The role of dissolved oxygen in supercritical water in the oxidation of
ferritic–martensitic steel
The Journal of Supercritical Fluids, Volume 108, February 2016, Pages 56-60
Zhongliang Zhu, Hong Xu, Dongfang Jiang, Guoqiang Yue, Baorang Li, Naiqiang
Zhang
Abstract
To assess the role of dissolved oxygen in supercritical water on the growth
processes of oxide scales, a marker experiment of ferritic–martensitic steel was
performed by exposing to supercritical water (H216O) containing marked 18O2 at
600 °C under 25 MPa. The oxide scale was analysed by using Secondary Ion Mass
Spectrometry (SIMS). The oxygen isotope profile shows that dissolved oxygen and
supercritical water react with metals simultaneously. Dissolved oxygen changes
the oxidation/reduction potential of supercritical water leading to an increase
in the oxidation rate. The oxidation rate increases with increase in dissolved
oxygen content in supercritical water. The mechanism of the effect of dissolved
oxygen on oxidation is discussed.
Hydrogen production by partial oxidation gasification of a phenol, naphthalene,
and acetic acid mixture in supercritical water
International Journal of Hydrogen Energy, Volume 41, Issue 4, 30 January 2016,
Pages 2238-2246
Yuzhen Wang, Shuzhong Wang, Gaoyang Zhao, Yanfeng Guo, Yang Guo
Abstract
A mixture of phenol, acetic acid, and naphthalene was partially oxidized in
supercritical water in order to produce hydrogen. The effects of temperature,
oxidation ratio (OR), reaction time, and reactant concentrations on gaseous
distributions, gasification efficiencies, and reactants removal efficiencies
were investigated. Furthermore, the effects of oxygen on the main intermediate
products were analyzed, and possible degradation pathways were proposed. Results
indicated that higher temperatures significantly promoted the H2 yield. In
addition, small amounts of oxygen (OR <0.2) accelerated the production of H2 and
CH4. The maximum H2 gasification efficiency (240.25%) and H2 yield (70.16 mmol
g−1) were obtained at 560 °C, 25 MPa, reaction time of 20 s and OR of 0.2.
Longer reaction time enhanced the gasification efficiencies in 10 s, while the
effect was little when reaction times longer than 10 s. The concentrations of
the reactants did not significantly influence the gasification efficiencies.
Supercritical water oxidation of a model fecal sludge without the use of a
co-fuel
Chemosphere, Volume 141, December 2015, Pages 189-196
A. Miller, R. Espanani, A. Junker, D. Hendry, N. Wilkinson, D. Bollinger, J.M.
Abelleira-Pereira, M.A. Deshusses, E. Inniss, W. Jacoby
Abstract
A continuous supercritical water oxidation reactor was designed and constructed
to investigate the conversion of a feces simulant without the use of a co-fuel.
The maximum reactor temperature and waste conversion was determined as a
function of stoichiometric excess of oxygen in order to determine factor levels
for subsequent investigation. 48% oxygen excess showed the highest temperature
with full conversion. Factorial analysis was then used to determine the effects
of feed concentration, oxygen excess, inlet temperature, and operating pressure
on the increase in the temperature of the reacting fluid as well as a newly
defined non-dimensional number, NJa representing heat transfer efficiency.
Operating pressure and stoichiometric excess oxygen were found to have the most
significant impacts on NJa. Feed concentration had a significant impact on fluid
temperature increase showing an average difference of 46.4 °C between the
factorial levels.
Salt deposition problems in supercritical water oxidation
Chemical Engineering Journal, Volume 279, 1 November 2015, Pages 1010-1022
Donghai Xu, Chuanbao Huang, Shuzhong Wang, Guike Lin, Yang Guo
Abstract
The cooled wall reactor has been modified by adding an additional upper outlet
of products at 500–700 °C to improve energy recovery and make possible energy
generation with the supercritical water oxidation of different waste.
Experimental and modeling results of the performance of this new reactor
configuration are presented as well as a theoretical analysis of the energy
recovery of the reactor compared to other supercritical water oxidation
reactors. Different flow distributions were tested to find the best elimination
conditions. Total organic carbon removal over 99.99% was obtained at room
injection temperatures, when the fraction of products leaving the reactor in the
upper effluent is lower than 70% of feed flow. The performance of the reactor
was tested with the oxidation of a recalcitrant compound such as ammonia.
Removals higher than 99% of were achieved at temperatures near 700 °C. The
behavior of the reactor working with feeds with up to 2.5% wt Na2SO4 could be
injected in the reactor without plugging problems. Upper effluent always
presented a concentration of salt lower than 30 ppm. Theoretical energetic
analysis shows that the performance of this reactor is superior to other designs
obtaining a maximum power efficiency of 27% (0.339 kW/kg-feed).
Supercritical water oxidation for energy production by hydrothermal flame as
internal heat source. Experimental results and energetic study
Energy, Volume 90, Part 2, October 2015, Pages 1584-1594
Pablo Cabeza, Joao Paulo Silva Queiroz, Manuel Criado, Cristina Jiménez, Maria
Dolores Bermejo, Fidel Mato, Maria Jose Cocero
Abstract
The cooled wall reactor has been modified by adding an additional upper outlet
of products at 500–700 °C to improve energy recovery and make possible energy
generation with the supercritical water oxidation of different waste.
Experimental and modeling results of the performance of this new reactor
configuration are presented as well as a theoretical analysis of the energy
recovery of the reactor compared to other supercritical water oxidation
reactors. Different flow distributions were tested to find the best elimination
conditions. Total organic carbon removal over 99.99% was obtained at room
injection temperatures, when the fraction of products leaving the reactor in the
upper effluent is lower than 70% of feed flow. The performance of the reactor
was tested with the oxidation of a recalcitrant compound such as ammonia.
Removals higher than 99% of were achieved at temperatures near 700 °C. The
behavior of the reactor working with feeds with up to 2.5% wt Na2SO4 could be
injected in the reactor without plugging problems. Upper effluent always
presented a concentration of salt lower than 30 ppm. Theoretical energetic
analysis shows that the performance of this reactor is superior to other designs
obtaining a maximum power efficiency of 27% (0.339 kW/kg-feed).
Study on catalytic and non-catalytic supercritical water oxidation of
p-nitrophenol wastewater
Chemical Engineering Journal, Volume 277, 1 October 2015, Pages 30-39
Xiuqin Dong, Zhongdong Gan, Xianlin Lu, Wenzhu Jin, Yingzhe Yu, Minhua Zhang
Abstract
Catalytic and non-catalytic supercritical water oxidation of p-nitrophenol
contained in wastewater was performed using compressed air and hydrogen peroxide
as an oxidant, respectively. In catalytic process, the supported Mn2O3/Ti-Al
oxide composite catalyst was employed to accelerate the reaction rate.
Experiments were conducted to investigate the effect of temperature, pressure,
oxygen excess or dosage of hydrogen peroxide and residence time on the
destruction of p-nitrophenol. Appropriate reaction conditions were obtained for
both processes. Based on the products generated in reaction, possible reaction
pathways were speculated. A possible mechanism was also proposed for the
catalytic process according to the experiments focused on the crystal structure
transformation in catalyst MnO2. The comparison of the two processes indicated
that hydrogen peroxide is a better oxidant without its cost taken into
consideration, and the reaction rate of catalytic process is much higher than
that in non-catalytic process in spite of the better oxidant used in it.
Partial oxidation of landfill leachate in supercritical water: Optimization by
response surface methodology
Waste Management, Volume 43, September 2015, Pages 343-352
Yanmeng Gong, Shuzhong Wang, Haidong Xu, Yang Guo, Xingying Tang
Abstract
To achieve the maximum H2 yield (GYH2), TOC removal rate (TRE) and carbon
recovery rate (CR), response surface methodology was applied to optimize the
process parameters for supercritical water partial oxidation (SWPO) of landfill
leachate in a batch reactor. Quadratic polynomial models for GYH2, CR and TRE
were established with Box–Behnken design. GYH2, CR and TRE reached up to 14.32
mmol·gTOC−1, 82.54% and 94.56% under optimum conditions, respectively. TRE was
invariably above 91.87%. In contrast, TC removal rate (TR) only changed from
8.76% to 32.98%. Furthermore, carbonate and bicarbonate were the most abundant
carbonaceous substances in product, whereas CO2 and H2 were the most abundant
gaseous products. As a product of nitrogen-containing organics, NH3 has an
important effect on gas composition. The carbon balance cannot be reached duo to
the formation of tar and char. CR increased with the increase of temperature and
oxidation coefficient.
Characterization of cerium dioxide nanoparticles prepared by supercritical water
oxidation
Ceramics International, Volume 41, Issue 8, September 2015, Pages 10170-10176
Hongxu Li, Chao Li, Chuanqi Jiao, Shuai Wang
Abstract
CeO2 nanoparticles with high purity and crystallinity were prepared by a
continuous supercritical water oxidation (SCWO) reaction. The phase composition,
microstructure, and morphology of the prepared CeO2 particles were characterized
by X-Ray diffraction (XRD), field emission scanning electron microscope
(FE-SEM), BET specific surface area (BET), and X-ray photoelectron spectroscopy
(XPS). The size distribution of the particles is narrow with an average particle
size between 10 and 13 nm; the diameter decreased gradually as the Ce(NO3)3·6H2O
concentration in the preparation increased. The BET results show an increase in
the products׳ specific surface area as the Ce(NO3)3·6H2O concentration
increased, with an average surface area of 48 m2 g−1. SEM micrographs reveal
that the CeO2 particles are spherical, and that higher Ce(NO3)3·6H2O
concentrations are conducive to the formation of smaller particles. However,
excess Ce(NO3)3·6H2O caused serious agglomeration, due to the higher surface
energy. XPS patterns indicate that Ce(III) was almost completely oxidized to
Ce(IV) in the reaction, and that the binding capacity of Ce–O reduced gradually
with increasing concentrations of Ce(NO3)3.
Hydrolysis and oxidation of sodium toluene sulfonate in sub-/supercritical water
in the presence of CO2 or H2O2
The Journal of Supercritical Fluids, Volume 107, January 2016, Pages 61-68
Hassan S. Ghaziaskar, Jalal Razavizade, Khosrow F. Zare
Abstract
The hydrolysis of sodium toluene sulfonate (STS) in sub-/supercritical water in
the presence of CO2 was investigated using a continuous flow system at the
constant pressure of 250 bar. The effect of water flow-rates, reaction
temperature and CO2 flow-rates on the hydrolysis of STS was investigated.
Results showed that hydrolysis of STS increases with the increase in temperature
and CO2 flow rate. The optimum reaction conditions calculated by partial
factorial design were 452 °C, water flow rate of 2.3 mL min−1 and CO2 flow rate
of 0.08 mL min−1. Furthermore, supercritical water was used for total removal of
STS from industrial wastewater using H2O2 as an oxidant. Results showed that at
temperatures higher than 350 °C more than 99% of STS is oxidized while COD
remains high until reaction temperature of 450 °C after which COD of solution
diminished 81%.
The oxidation resistance of thermo-mechanically processed Incoloy 800HT in
supercritical water
The Journal of Supercritical Fluids, Volume 101, June 2015, Pages 150-160
Hamed Akhiani, Majid Nezakat, Sami Penttilä, Jerzy Szpunar
Abstract
In this study, we evaluate the oxidation behavior of Incoloy 800HT with a view
to its feasible application in the Gen IV supercritical water-cooled reactor. To
evaluate the role of microstructure, we implement a specific thermo-mechanical
treatment to process Incoloy 800HT. The processed samples were exposed to
supercritical water for 100, 300 and 1000 h. We found that the thermo-mechanical
processing not only improves the oxidation resistance, but also alleviates the
oxide scale spallation. The results demonstrated that in compare with texture,
grain size has stronger effect on the oxidation resistance of Incoloy 800HT in
supercritical water.
A new system design for supercritical water oxidation
Chemical Engineering Journal, Volume 269, 1 June 2015, Pages 343-351
Zhong Chen, Guangwei Wang, Fengjun Yin, Hongzhen Chen, Yuanjian Xu
Abstract
As the main obstacles for the industrialization of supercritical water oxidation
(SCWO) technology, corrosion and plugging are mostly occurring in the high
pressure high temperature (HPHT) sections, including preheater, reactor, heat
exchanger and cooler. In this paper, a lab-scale SCWO system based on dynamic
gas seal wall reactor (DGSWR) has been described, tested and discussed in
detail. The results showed that the preheating problems of waste with high solid
content has been solved and the “gas seal” of DGSWR has been successfully
verified under 28–29 MPa and around 400 °C. Sewage sludge with 2.62–11.78% dry
solid has been degraded and the COD removal efficiency can reach up to 99.15%.
However, the solid particle sedimentation was only partly achieved. According to
the results analysis, based on the Stokes’ Law, both small particle size and
counter-current of upward reaction medium and downward solids are responsible.
Future improvements for the SCWO system were also discussed at the end of this
article.
The treatment of landfill leachate over Ni/Al2O3 by supercritical water
oxidation
The Journal of Supercritical Fluids, Volume 100, May 2015, Pages 7-14
Ferda Civan, Demet H. Özaltun, Ekin Kıpçak, Mesut Akgün
Abstract
This study presents the findings of our research regarding the catalytic
treatment of landfill leachate over Ni/Al2O3 by supercritical water oxidation.
Hydrogen peroxide was used as the oxygen source. The experiments were carried
out at a constant pressure of 25 MPa, in the temperature range of 400–600 °C and
the reaction time range of 30–150 s. The effects of temperature, reaction time,
pressure, catalyst and oxidant use on the total organic carbon and total
nitrogen contents of the liquid effluents were examined. As a result, it was
seen that supercritical water oxidation was a very effective method for the
treatment of landfill leachate. Treatment efficiencies up to 98.2% in terms of
total organic carbon conversion were obtained. However nitrogen removal achieved
about 57% in terms of total nitrogen conversion.
Partial oxidation of n-hexadecane through decomposition of hydrogen peroxide in
supercritical water
Chemical Engineering Research and Design, Volume 93, January 2015, Pages 565-575
Y.M. Alshammari, K. Hellgardt
Abstract
This work reports the experimental analysis of partial oxidation of n-hexadecane
under supercritical water conditions. A novel reactor flow system was developed
which allows for total decomposition of hydrogen peroxide in a separate reactor
followed partial oxidation of n-hexadecane in a gasification reactor instead of
having both reactions in one reactor. The kinetics of hydrothermal decomposition
of hydrogen peroxide was studied in order to confirm its full conversion into
water and oxygen under the desired partial oxidation conditions, and the kinetic
data were found in a good agreement with previously reported literature. The gas
yield and gasification efficiency were investigated under different operating
parameters. Furthermore, the profile of CC/CC ratio was studied which showed the
favourable conditions for maximising yields of n-alkanes via hydrogenation of
their corresponding 1-alkenes. Enhanced hydrogenation of 1-alkenes was observed
at higher O/C ratios and higher residence times, shown by the increase in the
CC/CC ratio to more than unity, while increasing the temperature has shown much
less effect on the CC/CC ratio at the current experimental conditions. In
addition, GC–MS analysis of liquid samples revealed the formation of heavy
oxygenated compounds which may suggest a new addition reaction to account for
their formation under the current experimental conditions. Results show new
promising routes for hydrogen production with in situ hydrogenation of heavy
hydrocarbons in a supercritical water reactor.
Supercritical water oxidation of a pesticide wastewater
Chemical Engineering Research and Design, Volume 94, February 2015, Pages
396-406
Donghai Xu, Shuzhong Wang, Jie Zhang, Xingying Tang, Yang Guo, Chuanbao Huang
Abstract
In this research, we studied supercritical water oxidation (SCWO) of a pesticide
wastewater under a wide range of operation conditions in two reaction plants.
The results show that reaction temperature, oxidant coefficient (OC), and
residence time (t) can improve the wastewater XCOD (removal efficiency of
chemical oxygen demand). The residence time and OC have important influences on
XCOD at higher reaction temperatures (>500 °C). It is significant to increase
the preheating rate for the XCOD improvement of the pesticide wastewater in
SCWO. XCOD and XTN (removal efficiency of total nitrogen) are 99.42% and 86.70%
at 600 °C, 25 MPa, OC = 3.0 and t = 2.0 min, respectively. More than 92 wt%
total organic carbon (TOC) and 86.70 wt% total nitrogen in the wastewater are
converted into CO2 and N2 under the above conditions, respectively. Inconel 625
can be used as the reactor material in the wastewater SCWO plant, and its
corrosion rate is approximately 0.6 mm/year at 600 °C, 25 MPa and OC = 3.0
conditions. We also primarily design a 100 t/d SCWO plant for the tested
pesticide wastewater treatment on the basis of accomplished investigations. SCWO
together with traditional wastewater treatment methods is proposed to harmlessly
dispose the complicated wastewater. This information is valuable for guiding the
large-scale SCWO plant design for pesticide wastewater treatment.
Supercritical water oxidation with hydrothermal flame as internal heat source:
Efficient and clean energy production from waste
The Journal of Supercritical Fluids, Volume 96, January 2015, Pages 103-113
J.P.S. Queiroz, M.D. Bermejo, F. Mato, M.J. Cocero
Abstract
Supercritical water oxidation (SCWO) has the potential to be considered a clean
energy generation process, as the process effluent is a high temperature, high
pressure stream with a high enthalpy content that can be converted to heat and
shaft work. In this work the state of the art of SCWO has been reviewed,
focusing on energy production. For the description of thermodynamic and
transport properties, there are some methods recommended for pure substances,
but the applicability of those methods for mixtures at supercritical state is
yet not clear. Most of the work found in literature use cubic equations of state
and linear mixing rules. The design of reactors has evolved in order to reduce
the drawbacks of corrosion and salt deposition, in general, through the dilution
of reaction products. In order to make the process profitable energetically
different strategies must be used to keep the products at the highest
temperature without compromising the safety, and the hydrothermal flames if
correctly stabilized are a good choice. Reactors and reaction systems able to
process feeds consisting of suspension with high inorganic contents without
diluting the effluent reducing its temperature must be developed. On the other
hand, the systems of energy recovery must be improved, especially the expanders,
in order to recover the pressure work as well as the thermal energy. Modeling
tools can help in both aspects. But for developing good models a good
comprehension of thermal and transport properties of mixtures at supercritical
state, as well as oxidation kinetics under that condition are essential data
that must be further investigated in order to find energetically efficient
processes.
Synthesis of manganese oxide microparticles using supercritical water
The Journal of Supercritical Fluids, Volume 112, June 2016, Pages 114-118
Minsoo Kim, Seung-Ah Hong, Naechul Shin, Keun Hwa Chae, Hong-shik Lee, Sun Choi,
Youhwan Shin
Abstract
Manganese compounds of different oxidation states such as MnO2, MnCO3 Mn2O3, and
a mixture of MnO + Mn3O4 were synthesized using supercritical water (SCW) and
calcination process. The X-ray Diffraction (XRD) patterns confirmed that the use
of glycerol as a reducing agent in SCW process was successful in preventing
oxidation of manganese products. Scanning electron microscopy (SEM) images of
the manganese products showed micro-sized particles with different morphology
depending on the product. The simple two step synthesis procedure described in
this paper allows easy control of manganese oxidation states with direct
applicability in large scale production on an industrial level.
Catalytic cracking of heavy petroleum residue in supercritical water: Study on
the effect of different metal oxide nanoparticles
The Journal of Supercritical Fluids, Volume 113, July 2016, Pages 136-143
Morteza Golmohammadi, Seyed Javad Ahmadi, Jafar Towfighi
Abstract
Cracking of heavy petroleum residue obtained from the vacuum distillation unit
in supercritical water (SCW) was performed with and without catalysts. First,
different nanoparticles, including CeO2, Co3O4, and MnO2 were synthesized in a
batchwise SCW reactor; then, the abilities of aforementioned nanocatalysts to
convert vacuum residue (VR) into the lighter fractions as well as their
stability under severe condition of supercritical water were examined. The X-ray
diffractometery (XRD) and transmission electron microscopy (TEM) images
indicated that the obtained nanoparticles with a satisfactory size and
morphology were synthesized under supercritical condition. VR cracking
experiments were also conducted in a batchwise reactor under operating
condition, namely temperature: 450 °C, reaction time: 60 min, catalyst/oil ratio
(g/g): 1/5, and water/oil ratio (g/g): 80/3. The performance of different
nanocatalysts was compared based on the yield of maltene, coke, and asphaltene
obtained from VR cracking. As a result, it was determined that the efficiency of
nanocatalysts in VR cracking diminishes in the order of CeO2 > Co3O4 > MnO2,
while the non-catalytic cracking or SCW pyrolysis attained the lowest rank with
a slight difference with the case of MnO2. Moreover, the XRD was utilized to
investigate the stability of different catalysts. The results demonstrated that
only CeO2 was stable, whereas the other catalysts were reduced to the lower
oxidation states during the reaction. Nevertheless, the scanning electron
microscopy (SEM) image and the Brunauer–Emmett–Teller (BET) surface area of
spent CeO2 showed the agglomeration of nanoparticles after the reaction.
Turnover rates for the supercritical water reforming of glycerol on supported Ni
and Ru catalysts
Fuel, Volume 180, 15 September 2016, Pages 417-423
F.J. Gutiérrez Ortiz, F.J. Campanario, P. Ollero
Abstract
Supercritical water reforming (SCWR) of glycerol conversion data to hydrogen are
reported as reaction rates, normalized by the number of ostensible catalytic
sites (i.e., as turnover rates). The process was studied in a tubular fixed-bed
reactor using commercial Ni/Al2O3–SiO2 and Ru/Al2O3 catalysts. The kinetic
results were captured as rate equations, and the Arrhenius parameters
(pre-exponential factor and apparent activation energy) were obtained. In this
way, a quantitative measure of catalytic activity of these catalysts was
achieved and can be used as a reference in other studies.
Catalytic supercritical water gasification of plastics with supported RuO2: A
potential solution to hydrocarbons–water pollution problem
Process Safety and Environmental Protection, Volume 102, July 2016, Pages
140-149
Jude A. Onwudili, Paul T. Williams
Abstract
Here we report on a potential catalytic process for efficient clean-up of
plastic pollution in waters, such as the Great Pacific Garbage Patch (GPGP).
Detailed catalytic mechanisms of RuO2 during supercritical water gasification of
common polyolefin plastics including low-density polyethylene (LDPE),
high-density polyethylene (HDPE), polypropylene (PP) and polystyrene (PP) have
been investigated in a batch reactor at 450 °C for 60 min. All four plastics
gave very high carbon gasification efficiencies (CGE) and hydrogen gasification
efficiencies (HGE). Methane was the highest gas component, with a yield of up to
37 mol kg−1 LDPE using the 20 wt% RuO2 catalyst. Evaluation of the gas yields,
CGE and HGE revealed that the conversion of PS involved thermal degradation,
steam reforming and methanation; whereas hydrogenolysis was a possible
additional mechanism during the conversion of aliphatic plastics. The process
has the benefits of producing a clean-pressurized methane-rich fuel gas as well
as cleaning up hydrocarbons-polluted waters.
Effects of reaction time and catalyst on gasification of glucose in
supercritical water: Detailed reaction pathway and mechanisms
International Journal of Hydrogen Energy, Volume 41, Issue 16, 4 May 2016, Pages
6630-6639
Chao Zhu, Liejin Guo, Hui Jin, Jianbing Huang, Sha Li, Xiaoyan Lian
Abstract
Supercritical water gasification of glucose as a model compound for biomass was
conducted in quartz reactors at 500 °C. The concentration of glucose solution
was 5 wt.% and the reaction time was adjusted within the range of 10–1800 s. The
effects of reaction time and catalyst on the product distribution were
investigated and the formation and degradation pathways of intermediate products
with and without catalyst were discussed. The results show that the gas yields
increased while the yields of organic intermediates in residual liquid decreased
with the reaction time. The organic intermediates in residual liquid were mainly
composed of phenols, furans, organic acids, alcohols, arenes and ketones. The
Ru/Al2O3 catalyst had a significant influence on the gasification of glucose,
which promoted the degradation of intermediates to gaseous products, increased
the yield of hydrogen and inhibited the formation of char.
Influence of the reactant carbon–hydrogen–oxygen composition on the key products
of the direct gasification of dewatered sewage sludge in supercritical water
Bioresource Technology, Volume 208, May 2016, Pages 81-86
Miao Gong, Wei Zhu, Yujie Fan, Huiwen Zhang, Ying Su
Abstract
The supercritical water gasification of ten different types of dewatered sewage
sludges was investigated to understand the relationship between sludge
properties and gasification products. Experiments were performed in a
high-pressure autoclave at 400 °C for 60 min. Results showed that gasification
of sewage sludge in supercritical water consists mainly of a gasification
reaction, a carbonization reaction and a persistent organic pollutants synthesis
reaction. Changes in the reactant C/H/O composition have significant effects on
the key gasification products. Total gas production increased with increasing
C/H2O of the reactant. The char/coke content increased with increasing C/H ratio
of the reactant. A decrease in the C/O ratio of the reactant led to a reduction
in polycyclic aromatic hydrocarbon formation. This means that we can adjust the
reactant C/H/O composition by adding carbon-, hydrogen-, and oxygen-containing
substances such as coal, algae and H2O2 to optimize hydrogen production and to
inhibit an undesired by-product formation.
Hydrogen production from lignin, cellulose and waste biomass via supercritical
water gasification: Catalyst activity and process optimization study
Energy Conversion and Management, Volume 117, 1 June 2016, Pages 528-537
Kang Kang, Ramin Azargohar, Ajay K. Dalai, Hui Wang
Abstract
Process optimization for catalytic biomass supercritical water gasification
process (SCWG) was performed. By catalysts screening using cellulose and lignin
as biomass model compounds, K2CO3 and 20Ni0.36Ce/Al2O3 were identified as the
best catalysts. Then, an optimization study based on Taguchi experimental design
was conducted, and waste biomass including wheat straw, canola meal, and timothy
grass were used as feedstock. The effect of different parameters are studied.
For these parameters, the order of relative importance for hydrogen production
is: temperature > catalyst loading > catalyst type > biomass type. High
temperature (∼650 °C), and high catalyst loading (∼100%) are favorable for
hydrogen production. The average hydrogen yield using different waste biomass
was in the order of: canola meal > wheat straw > timothy grass.
Transpiring wall reactor in supercritical water oxidationReview Article
Chemical Engineering Research and Design, Volume 92, Issue 11, November 2014,
Pages 2626-2639
Donghai Xu, Shuzhong Wang, Chuanbao Huang, Xingying Tang, Yang Guo
Abstract
Reactor corrosion and plugging problems have hindered the commercialization of
supercritical water oxidation (SCWO) for wastewater purification. The use of
transpiring wall reactor (TWR) is an effective means to overcome the above two
problems by forming a protective water film on the internal surface of the
reactor to aviod contacting corrosive species and precipitated organic salts.
This work mainly aims to objectively review experimental investigations and
numerical simulation results concerning TWR. Subsequent investigations for
parameters optimizations of TWR are also proposed in order to ultimately build
effective regulation methods of obtaining excellent water film properties. All
this information is very important in guiding the structure design and operation
parameters optimization of TWR.
The products of heavy sulfur-rich oil conversion in a counter supercritical
water flow and their desulfurization by ZnO nanoparticles
The Journal of Supercritical Fluids, Volume 111, May 2016, Pages 121-128
Oxana N. Fedyaeva, Anatoly A. Vostrikov
Abstract
The conversion of heavy sulfur-rich oil (gross-formula CH1.59N0.01S0.027O0.03)
under its continuous supply into a counter supercritical water (SCW) flow and
the temperature gradient along the reactor axis (at the top −400 °C and at the
bottom −550 °C) at 30 MPa has been studied. The products dissolved in SCW were
alternately discharged from the reactor into the samplers through two parallel
pipelines, on one of which the cell, heated up to 400 °C and loaded with ZnO
nanoparticles, was mounted. Zinc oxide was synthesized during pumping SCW
through a layer of zinc shavings at 400 °C, 30 MPa. The yields of volatile and
liquid products and conversion residue have been found to be equal to 23.5,
62.8, and 11.9%, respectively, relative to the weight of oil supplied into the
reactor. Upon SCW conversion the fraction of asphaltene in the liquid products
was found to have decreased from 12 to 1 wt% while the fraction of saturated
hydrocarbons increased by 4–5 times as much, compared to crude oil. The
composition of the liquid products is defined by means of gas–liquid
chromatography, IR and 1H NMR spectroscopy. When reactants were pumped through
the cell loaded with ZnO, zinc sulfide was formed as a result of the interaction
of S-containing products with ZnO accompanied by near complete removal of H2S,
decrease in the S/C atomic ratio in group components of the liquid products and
insignificant increase in the O/C atomic ratio and fraction of resin in the
liquid products.
Co-oxidation of ammonia and isopropanol in supercritical water in a tubular
reactor
Chemical Engineering Research and Design, Volume 92, Issue 11, November 2014,
Pages 2568-2574
P. Cabeza, B. Al-Duri, M.D. Bermejo, M.J. Cocero
Abstract
Improvements in the ammonia removal were only appreciated with the lowest
IPA/NH3 molar ratios (0.125 and 0.25) while the oxygen ratio did not have
significant influence in the ammonia removal. Nevertheless, a direct relation
between the nitrate concentration and the oxygen in excess was found. Nitrate
concentration was also found to increase when the IPA/ammonia ratio increased.
Oxidation of ferritic and ferritic–martensitic steels in flowing and static
supercritical water
Corrosion Science, Volume 103, February 2016, Pages 124-131
Nai-qiang Zhang, Zhong-liang Zhu, Hong Xu, Xue-ping Mao, Ju Li
Abstract
The oxidation of ferritic steel and ferritic–martensitic steel was investigated
by exposure to flowing and static supercritical water (SCW) at 550–600 °C. The
oxidation kinetic curves follow parabolic and near-cubic rate equations for the
samples exposed to flowing and static SCW, respectively. The phase analysis
shows the presence of hematite, magnetite and spinel in flowing SCW while only
the magnetite and spinel phases are identified in static SCW. The mechanism of
the formation of hematite and the effect of the flow state of SCW on the time
exponent of oxidation kinetics are discussed.
Polycyclic aromatic hydrocarbon formation from gasification of sewage sludge in
supercritical water: The concentration distribution and effect of sludge
properties
The Journal of Supercritical Fluids, Volume 113, July 2016, Pages 112-118
Miao Gong, Wei Zhu, Huiwen Zhang, Ying Su, Yujie Fan
Abstract
The changes in the polycyclic aromatic hydrocarbon (PAH) concentration and
distribution in 10 different types of raw sewage sludge and gasified residues
were investigated, and the effects of the sludge properties and the organic
matter composition were determined. The results showed that the concentrations
of 2-ring and 6-ring PAHs increased significantly during the gasification
process. The PAHs in raw sludge were dominated by 3-ring and 4-ring PAHs, and
those after gasification were dominated by 2-ring and 3-ring PAHs. The total PAH
concentration increased with the increasing volatile matter content and
decreased with the increasing pH value. Phenols have been considered to be
important precursors for PAH synthesis. The crude fat and carbohydrate content
can promote lower-molecular-weight PAH formation, while lignin and humic
substance content can promote higher-molecular-weight PAH formation, which
indicates that the organic matter composition in raw sludge has a high impact on
the PAH distribution.
Treatment of municipal sewage sludge in supercritical water: A reviewReview
Article
Water Research, Volume 89, 1 February 2016, Pages 118-131
Lili Qian, Shuzhong Wang, Donghai Xu, Yang Guo, Xingying Tang, Laisheng Wang
Abstract
With increasing construction of wastewater treatment plants and stricter
policies, municipal sewage sludge (MSS) disposal has become a serious problem.
Treatment of MSS in supercritical water (SCW) can avoid the pre-drying procedure
and secondary pollution of conventional methods. SCW treatment methods can be
divided into supercritical water gasification (SCWG), supercritical water
partial oxidation (SCWPO) and supercritical water oxidation (SCWO) technologies
with increasing amounts of oxidants. Hydrogen-rich gases can be generated from
MSS by SCWG or SCWPO technology using oxidants less than stoichiometric ratio
while organic compounds can be completely degraded by SCWO technology with using
an oxidant excess. For SCWG and SCWPO technologies, this paper reviews the
influences of different process variables (MSS properties, moisture content,
temperature, oxidant amount and catalysts) on the production of gases. For SCWO
technology, this paper reviews research regarding the removal of organics with
or without hydrothermal flames and the changes in heavy metal speciation and
risk. Finally, typical systems for handling MSS are summarized and research
needs and challenges are proposed.
Study of transpiring fluid dynamics in supercritical water oxidation using a
transparent reactor
The Journal of Supercritical Fluids, Volume 88, April 2014, Pages 117-125
Zhong Chen, Guangwei Wang, Zakaria. A. Mirza, Shu Yang, Yuanjian Xu
Abstract
The transpiring wall reactor (TWR) is considered to be one of the most promising
reactors because it minimizes both corrosion and salt precipitation problems
that seriously hinder the industrialization of supercritical water oxidation
technologies. A transparent reactor is built to study the fluid dynamics of
transpiring flow, which are the foundation of reactor design and optimization.
The results showed that the transpiring flow is anisotropic with respect to the
surface of the transpiring wall due to both the static pressure and viscous
resistance. Finally, the novel idea of using air as the transpiring fluid
instead of water is presented in an attempt to alleviate current TWR problems
such as high energy consumption, high volume of pure water consumption, and
temperature fluctuation in the reaction area. A series of experiments and
theoretical derivations demonstrate that this novel idea is feasible.
Chapter 10 - Oxidation in High-Temperature and Supercritical Water
Supercritical Fluid Science and Technology, Volume 5, 2014, Pages 525-568
Gerd Brunner
Abstract
In this chapter, the application of hydrothermal and supercritical water is
discussed for eliminating toxic and dangerous compound by oxidation in an
aqueous environment. Oxidation can be carried out as oxidation in a liquid
aqueous environment in the temperature range from T = 100–374 °C, as wet air
oxidation (WAO), or as oxidation in supercritical water, known as supercritical
water oxidation (SCWO), and as oxidation in the so-called “hydrothermal flames.”
These oxidation reactions aim at the conversion of the organic compounds to
totally oxidized end products or such effluents that can be further treated with
conventional wastewater cleaning methods. For some applications, for example,
for conversion of methane to methanol, partial oxidation is of interest.
Oxidation in high-temperature and supercritical water refers to the oxidation of
organic compounds in water at high temperatures and elevated pressures. It
comprises (i) oxidation in a liquid aqueous environment in the temperature range
from T = 100–374 °C, known as WAO, since in most cases, air is used as oxidation
agent; (ii) oxidation in supercritical water, known as SCWO at temperatures
above the critical temperature of water in the range of up to about T = 550 °C;
and (iii) the oxidation of organic compounds in water in the so-called
“hydrothermal flames” at temperatures higher than T = 1000 °C. All oxidation
reactions aim at the conversion of the organic compounds, mostly to totally
oxidized end products, but also in some cases as partial oxidation, for the
purpose of forming interesting intermediate products. Nevertheless, the main
goal of such oxidation processes is the conversion of waste compounds to
harmless oxidation products.
In WAO, the oxidation is carried out usually at moderate pressures that can go
up to P = 20 MPa, if the temperature needed for the conversion approaches the
critical temperature of water. The oxidation is moderately fast and takes about
t = 1–3 h for the oxidation reaction. In SCWO, pressures are higher than in WAO,
but not necessarily higher than the critical pressure of water. The oxidation
reaction is fast and takes typically less than t = 60 s. The special properties
of water at supercritical conditions not only make possible to control the
reaction via density but also make it necessary to take care of precipitating
salts. In hydrothermal flames, pressures are high, typically higher than the
critical pressure of water, and the reaction is very fast in the range of t = 1
ms to t = 1 s. In all three cases, corrosion is a major issue.
In this chapter, fundamentals and applications of WAO, SCWO, and hydrothermal
flames are described with examples given. Process conditions as derived from
basic experiments and process verifications are discussed.
Valorization of horse manure through catalytic supercritical water gasification
Waste Management, In Press, Corrected Proof, Available online 5 April 2016
Sonil Nanda, Ajay K. Dalai, Iskender Gökalp, Janusz A. Kozinski
Abstract
The organic wastes such as lignocellulosic biomass, municipal solid waste,
sewage sludge and livestock manure have attracted attention as alternative
sources of energy. Cattle manure, a waste generated in surplus amounts from the
feedlot, has always been a chief environmental concern. This study is focused on
identifying the candidacy of horse manure as a next generation feedstock for
biofuel production through supercritical water gasification. The horse manure
was gasified in supercritical water to examine the effects of temperature
(400–600 °C), biomass-to-water ratio (1:5 and 1:10) and reaction time (15–45
min) at a pressure range of 23–25 MPa. The horse manure and resulting biochar
were characterized through carbon-hydrogen-nitrogen-sulfur (CHNS), inductively
coupled plasma-mass spectrometry (ICP-MS), thermogravimetric analysis (TGA),
Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and scanning
electron microscopy (SEM). The effects of alkali catalysts such as NaOH, Na2CO3
and K2CO3 at variable concentrations (1–2 wt%) were investigated to maximize the
hydrogen yields. Supercritical water gasification of horse manure with 2 wt%
Na2CO3 at 600 °C and 1:10 biomass-to-water ratio for 45 min revealed maximum
hydrogen yields (5.31 mmol/g), total gas yields (20.8 mmol/g) with greater
carbon conversion efficiency (43.1%) and enhanced lower heating value of gas
products (2920 kJ/Nm3). The manure-derived biochars generated at temperatures
higher than 500 °C also demonstrated higher thermal stability (weight loss <34%)
and larger carbon content (>70 wt%) suggesting their application in enhancing
soil fertility and carbon sequestration. The results propose that supercritical
water gasification could be a proficient remediation technology for horse manure
to generate hydrogen-rich gas products.
Experimental study on the operating characteristics of an inner preheating
transpiring wall reactor for supercritical water oxidation: Temperature profiles
and product properties
Energy, Volume 66, 1 March 2014, Pages 577-587
Fengming Zhang, Chunyan Xu, Yong Zhang, Shouyan Chen, Guifang Chen, Chunyuan Ma
Abstract
A new process to generate multiple thermal fluids by supercritical water
oxidation (SCWO) was proposed to enhance oil recovery. An inner preheating
transpiring wall reactor for SCWO was designed and tested to avoid plugging in
the preheating section. Hot water (400–600 °C) was used as auxiliary heat source
to preheat the feed to the reaction temperature. The effect of different
operating parameters on the performance of the inner preheating transpiring wall
reactor was investigated, and the optimized operating parameters were determined
based on temperature profiles and product properties. The reaction temperature
is close to 900 °C at an auxiliary heat source flow of 2.79 kg/h, and the
auxiliary heat source flow is determined at 6–14 kg/h to avoid the overheating
of the reactor. The useful reaction time is used to quantitatively describe the
feed degradation efficiency. The outlet concentration of total organic carbon
(TOCout) and CO in the effluent gradually decreases with increasing useful
reaction time. The useful reaction time needed for complete oxidation of the
feed is 10.5 s for the reactor.
Energetic analysis of gasification of biomass by partial oxidation in
supercritical water
Chinese Journal of Chemical Engineering, Volume 23, Issue 1, January 2015, Pages
205-212
Qingqing Guan, Chaohai Wei, Xinsheng Chai, Ping Ning, Senlin Tian, Junjie Gu,
Qiuling Chen, Rongrong Miao
Abstract
Partial oxidation gasification in supercritical water could produce fuel gases
(such as H2, CO and CH4) and significantly reduce the energy consumption. In
this work, an energetic model was developed to analyze the partial oxidative
gasification of biomass (glucose and lignin) in supercritical water and the
related key factors on which gasification under autothermal condition depended
upon. The results indicated that the oxidant equivalent ratio (ER) should be
over 0.3 as the concern about energy balance but less than 0.6 as the concern
about fuel gas production. Feedstocks such as glucose and lignin also had
different energy recovery efficiency. For materials which can be efficiently
gasified, the partial oxidation might be a way for energy based on the
combustion of fuel gases. Aromatic materials such as lignin and coal are more
potential since partial oxidation could produce similar amount of fuel gases as
direct gasification and offer additional energy. Energy recovered pays a key
role to achieve an autothermal process. Keeping heat exchanger efficiency above
80% and heat transfer coefficient below 15 kJ·s− 1 is necessary to maintain the
autothermal status. The results also indicated that the biomass loading should
be above 15% but under 20% for an autothermal gasification, since the increase
of biomass loading could improve the energy supplied but decrease the efficiency
of gasification and gaseous yields. In general, some specific conditions exist
among different materials.
Treatment of sewage sludge in supercritical water and evaluation of the combined
process of supercritical water gasification and oxidation
Bioresource Technology, Volume 176, January 2015, Pages 218-224
Lili Qian, Shuzhong Wang, Donghai Xu, Yang Guo, Xingying Tang, Longfei Wang
Abstract
Influences of temperature and oxidation coefficient (n) on sewage sludge
treatment in supercritical water and its corresponding reaction mechanism were
studied. Moreover, the combined process of supercritical water gasification
(SCWG) and supercritical water oxidation (SCWO) was also investigated. The
results show that ammonia nitrogen, phenols and pyridines are main refractory
intermediates. The weight of solid products at 873 K and n = 4 is only 3.5 wt.%
of the initial weight, which is lower than that after combustion. Volatile
organics in solid phase have almost released at 723 K and n = 0. Highest yield
of combustible gases was obtained at n = 0, and H2 yield can reach 11.81 mol/kg
at 873 K. Furthermore, the combination of SCWG at 723 K and SCWO at 873 K with a
total n = 1 is feasible for its good effluent quality and low operation costs.
Deuterium tracing study of unsaturated aliphatics hydrogenation by supercritical
water in upgrading heavy oil. Part II: Hydrogen donating capacity of water in
the presence of iron(III) oxide nanocatalyst
The Journal of Supercritical Fluids, Volume 110, April 2016, Pages 75-82
Morteza Hosseinpour, Shohreh Fatemi, Seyed Javad Ahmadi
Abstract
This paper is the second part of the vacuum residue (VR) cracking in
supercritical water and tracking the chemical behavior of water as the hydrogen
donor, using supercritical deuterium oxide (SC-D2O). In this research,
hydrogen-donating capacity of water is enhanced and investigated by using
heterogeneous catalyst of silica-supported iron oxide nanoparticles. Upgrading
process in the absence of catalyst has been reported at Part I, where a simple
comparative index, namely Hrel, was introduced in order to determine the
hydrogen contribution capacity of SC-H2O versus hydrocarbons through
hydrogenation of unsaturated compounds. Hexane soluble fraction (maltene) of the
product was analyzed by attenuated total reflectance infrared
(ATR-IR)spectroscopy, and it has revealed more than two fold increase in
contribution of hydrogen of water (Hrel = 35%) in catalytic cracking with lower
coke (8.4 wt%) formation, compared with non-catalytic cracking (Hrel = 16%) with
18.9 wt% of coke yield. In addition, gas chromatography analysis coupled with
mass spectroscopy (GC–MS) has revealed higher fractions of n-alkane in maltene
produced from catalytic cracking compared with non-catalytic process. The
average physical properties of the prepared maltene such as molecular weight,
density and viscosity were calculated by Aspen Plus@ engineering software and
they were predicted as: 87.1 g/mol, 0.69 g/ml and 0.33 cp, respectively, for the
catalytic cracking, versus; 105.54 g/mol, 0.70 g/ml and 0.47 cp in non-catalytic
process. The results indicate that nano iron oxide catalyst is effective towards
hydrogenation of the unsaturated fragments in VR cracking by supercritical
water, with less coke formation.
Sub- and supercritical water hydrolysis of agricultural and food industry
residues for the production of fermentable sugars: A reviewReview Article
Food and Bioproducts Processing, Volume 98, April 2016, Pages 95-123
Juliana M. Prado, Daniel Lachos-Perez, Tânia Forster-Carneiro, Mauricio A.
Rostagno
Abstract
Bioethanol has been researched as a potential alternative to substitute liquid
fossil fuels due to its eco-friendly characteristics and relatively low
production cost when compared to other bio-based fuels. First generation
bioethanol is produced from raw materials rich in simple sugars or starch, such
as sugarcane and corn, which are food sources. To avoid the fuel versus food
dilemma, second generation bioethanol aims at using non-edible raw materials, as
lignocellulosic agricultural residues, as source of fermentable sugars.
Hydrolysis with sub/supercritical water has demonstrated great potential to
decompose the lignocellulosic complex into simple sugars with several advantages
over conventional processes. This review provides an overview of the state of
the art on hydrolysis with sub- and supercritical water in the context of the
reuse of agricultural residues to produce suitable fermentation substrates for
the production of second generation bioethanol. Recent applications and advances
are put into context together, providing an insight into future research trends.
Chapter 9 - Supercritical Water Oxidation for Wastewater Destruction with Energy
Recovery
Supercritical Fluid Technology for Energy and Environmental Applications, 2014,
Pages 181-190
Violeta Vadillo, Jezabel Sánchez-Oneto, Juan R. Portela, Enrique J. Martínez de
la Ossa
Abstract
Supercritical water oxidation (SCWO) is a promising technology that respecting
the environment destroys wastes definitely and allows an energy recovery. This
process has been applied to many model compounds and real wastewaters at
laboratory scale. However SCWO treatments at pilot plant scale of real
wastewaters are much more limited in literature. Furthermore, the application of
this technology to industrial wastewaters has some drawbacks as corrosion, salt
deposition, management of biphasic wastes, presence of suspended solids and high
costs, so nowadays the industrial scale-up is scarce and it is being delayed. As
an attempt to reduce process costs, energy recovery from the effluent of the
reactor has been studied by several authors. In this chapter, the main aspects
of the SCWO are briefly described and the studies regarding energy recovery are
summarized.
Supercritical water oxidation of polyvinyl alcohol and desizing wastewater:
Influence of NaOH on the organic decomposition
Journal of Environmental Sciences, Volume 25, Issue 8, 1 August 2013, Pages
1583-1591
Jie Zhang, Shuzhong Wang, Yang Guo, Donghai Xu, Yanmeng Gong, Xingying Tang
Abstract
Polyvinyl alcohol is a refractory compound widely used in industry. Here we
report supercritical water oxidation of polyvinyl alcohol solution and desizing
wastewater with and without sodium hydroxide addition. However, it is difficult
to implement complete degradation of organics even though polyvinyl alcohol can
readily crack under supercritical water treatment. Sodium hydroxide had a
significant catalytic effect during the supercritical water oxidation of
polyvinyl alcohol. It appears that the OH− ion participated in the C–C bond
cleavage of polyvinyl alcohol molecules, the CO2-capture reaction and the
neutralization of intermediate organic acids, promoting the overall reactions
moving in the forward direction. Acetaldehyde was a typical intermediate product
during reaction. For supercritical water oxidation of desizing wastewater, a
high destruction rate (98.25%) based on total organic carbon was achieved. In
addition, cases where initial wastewater was alkaline were favorable for
supercritical water oxidation treatment, but salt precipitation and blockage
issues arising during the process need to be taken into account seriously.
Mechanism of glucose conversion in
supercritical water by DFT study
Journal of Analytical and Applied Pyrolysis, In Press, Corrected Proof,
Available online 15 March 2016
Yayun Zhang, Chao Liu, Xi Chen
Abstract
Using density function theory (DFT) simulations with B3LYP/AGU-cc-pVDZ level of
theory, six chemical reaction pathways of glucose decomposition in supercritical
water were proposed to explore the formation mechanism of some main outcomes
(levoglucosan, 5-hydroxymethylfurfural, hydroxylacetaldehyde, erythrose,
glyceraldehyde and fructose). In addition, seven potential dehydration ways in
glucose were investigated with and without the assistance of water molecule. All
dehydration reactions are accelerated when water molecules take part in the
reaction, because it can effectively lower the energy barrier of dehydration
reaction. In supercritical water surrounding with assistant of water molecule,
pathways 3 and 4 are preferred routes of glucose conversion to
hydroxylacetaldehyde and erythrose with the lowest energy barrier of 127 kJ/mol.
While a higher energy barrier (163 kJ/mol) is required to form glyceraldehyde
and fructose in pathways 5 and 6. Levoglucosan and 5-hydroxymethylfurfural are
hard to generate during this chemical processes because of their higher energy
barrier without water participating in. It seems like that water molecule acts
as a magic catalyst that can transfer hydrogen atom in dehydrations, keto-enol
tautomerization and structure rearrangement, which reducing the distance of
hydrogen atom moving, result in reducing these reactions energy barriers
dramatically. The computational results open a window to produce
hydroxylacetaldehyde and erythrose in theory. Moreover, it sheds some light on
the various proportions of different products in conversion of glucose in
supercritical water, as well as suggesting concrete reaction pathways to form
these main products, contributing to the elaboration of the mechanism of glucose
conversion and cellulose decomposition from a molecule level.
Hydrogen production by non-catalytic partial oxidation of coal in supercritical
water: Explore the way to complete gasification of lignite and bituminous coal
International Journal of Hydrogen Energy, Volume 38, Issue 29, 30 September
2013, Pages 12786-12794
Zhiwei Ge, Simao Guo, Liejin Guo, Changqing Cao, Xiaohui Su, Hui Jin
Abstract
Supercritical water gasification (SCWG) of coal is a promising technology for
clean coal utilization. In this paper, hydrogen production by non-catalytic
partial oxidation of coal was systematically investigated in supercritical water
(SCW) with quartz batch reactors for the first time. The influences of the main
operating parameters including residence time, temperature, oxidant equivalent
ratio (ER) and feed concentration on the gasification characteristics of coal
were investigated. The experimental results showed that H2 yield and carbon
gasification efficiency (CE) increased with increasing temperature and
decreasing feed concentration. CE increased with increasing ER, and H2 yield
peaked when ER equaled 0.1. CE increased quickly within 1 min and then tended to
be stable between 2 and 3 min. In particular, complete gasification of lignite
was obtained at 950 °C when ER equaled 0.1, as for bituminous coal, at a higher
temperature of 980 °C when ER equaled 0.2.
The use of dimensionless groups to analyse the mixing of streams with large
density differences in sub- and supercritical water
Chemical Engineering Journal, Volume 287, 1 March 2016, Pages 350-358
Duncan Housley, Thomas Huddle, Edward Lester, Martyn Poliakoff
Abstract
As water approaches supercritical conditions, it undergoes sharp changes in
density, dielectrics, surface tension and viscosity. Thus, the mixing of
supercritical and sub-critical water streams can be potentially impacted by the
vast differences in the properties of each fluid.
The reactor configurations employed have been characterised using previously
reported experimental techniques for assessing the mixing performance in systems
with large density gradients. The results obtained have been used to construct a
model framework characterised by the turbulence, relative stream momenta and
relative buoyancy of the different streams. This has been applied to rationalise
the observed reaction outcomes.
The results in this paper demonstrate the need for caution when comparing sets
of data from supercritical water reactors, undertaken with differing reactor
geometries.
Catalytic gasification of lignite in supercritical water with Ru/CeO2–ZrO2
International Journal of Hydrogen Energy, Volume 41, Issue 8, 2 March 2016,
Pages 4579-4591
Jiangdong Yu, Xiuyun Lu, Yunjie Shi, Qiuling Chen, Qingqing Guan, Ping Ning,
Senlin Tian, Junjie Gu
Abstract
A series of CeO2–ZrO2 (CZ) supported Ru catalysts were prepared and employed to
catalytic gasification of lignite in supercritical water (SCW). The influences
of Ru content, catalyst loading, reaction temperature and feed concentration on
gasification of lignite were investigated. Results indicated that Ru2/CZ shows
high activity for gasification of lignite and hydrogen production. At 500 °C and
17 min with a 2 wt% loading of lignite and a 2 g/g catalyst loading, carbon
gasification efficiency about 86% has been achieved and the highest H2 yield
(29.24 mol/kg) has been produced, representing nearly 21-fold enhancement of
yield compared to that in the noncatalytic case. The kinetic study in terms of
overall reaction rate was investigated and the activation energy Ea is 130 ± 26
kJ/mol. Furthermore, catalyst recycling experiments were conducted in order to
evaluate the stability of Ru2/CZ catalyst. The results and XPS data indicate
that ZrO2 enhance the stability of the catalyst. Thus, the Ru2/CZ catalyst seems
to be a promising material for SCWG of lignite for gas fuels, especially for
hydrogen.
Non-isothermal conversion of the Kashpir sulfur-rich oil shale in a
supercritical water flow
The Journal of Supercritical Fluids, Volume 109, March 2016, Pages 157-165
Oxana N. Fedyaeva, Vladimir R. Antipenko, Dmitriy Yu. Dubov, Tatyana V.
Kruglyakova, Anatoly A. Vostrikov
Abstract
The conversion of the Kashpir oil shale (gross-formula CH1.48N0.01S0.10O0.24) in
a flow of water vapor and supercritical water at uniform increase in temperature
(dT/dt = 1 °C/min) from 300 to 550 °C has been studied. Temperature dependences
of the yields of the volatile and liquid products and their component and
elemental compositions have been determined. The total yields of the volatile
and liquid products and the conversion residue formed during the experiment have
been found to be equal to 404.8, 383.8, and 543.0 mg/gC, respectively. The
maximum yield of the volatile products, containing H2S, CO2, H2, and CH4 as
major components, is observed at 300–360 °C. A high yield of these compounds is
brought about by the redox reactions of oil shale organic matter and mineral
components with water. The maximum yield of the liquid products is observed at
360–390 °C, the oil fraction in their composition increasing from 57% to 78%
along with increase in temperature. The composition of the liquid products is
defined by means of IR and 1H NMR spectroscopy. A new approach to the problem of
the Kashpir oil shale processing in SCW in order to obtain the desired
S-containing products is discussed.
Catalytic bitumen cracking in sub- and supercritical water
Fuel Processing Technology, Volume 142, February 2016, Pages 315-318
Xi-Kun Gai, Hiroyuki Arano, Peng Lu, Jian-Wei Mao, Yoshiharu Yoneyama, Cheng-Xue
Lu, Rui-Qin Yang, Noritatsu Tsubaki
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Production of methane and hydrogen via supercritical water gasification of
renewable glucose at a relatively low temperature: Effects of metal catalysts
and supportsOriginal Research Article
Fuel Processing Technology, Volume 143, March 2016, Pages 27-34
Izad Behnia, Zhongshun Yuan, Paul Charpentier, Chunbao (Charles) Xu
Abstract
The activities of various supported catalysts were tested in a continuous flow
reactor for production of CH4 and H2 from glucose via supercritical water
gasification (SCWG) at a relatively low temperature (500 °C). Based on this
preliminary study, among all catalysts tested in this study Ni20%Ru2%/γ-Al2O3
catalyst was found to be the most active, achieving complete conversion of all
carbon in glucose at 500 °C and a weight-hourly space velocity (WHSV) of 3 h− 1.
The addition of 2% Ru to Ni20%/γ-Al2O3 not only suppressed char/tar formation,
promoted the carbon gasification efficiently, but also increased methane
formation. Moreover, high stability of Ni20%Ru2%/γ-Al2O3 catalyst was
demonstrated in the experimental runs for 20 h on-stream. The roles of ruthenium
as a co-catalyst in Ni/Al2O3 were found to be not only increasing nickel
dispersion, enhancing nickel's reducibility, but also preventing leaching of Al
and Ni metals in SCW. However, NiRu supported on either TiO2 and activated
carbon led to lower catalytic activity and frequent plugging after only 3 h
on-stream.
Supercritical water reforming of glycerol: Performance of Ru and Ni catalysts on
Al2O3 support
Energy, Volume 96, 1 February 2016, Pages 561-568
F.J. Gutiérrez Ortiz, F.J. Campanario, P.G. Aguilera, P. Ollero
Abstract
Supercritical water reforming of glycerol was studied in a tubular fixed-bed
reactor using a Ru/Al2O3 catalyst, and was compared with our previous study
using a Ni-based catalyst, with the aim of enhancing the performance of a global
process designed under energy self-sufficient conditions. Relatively high
glycerol concentrations of up to 25 wt.% and temperatures from 500 to 800 °C
were tested. Glycerol conversion was very high (>99%) at temperatures of 600 °C
and above, but low at 500 and 550 °C (<50%) using the Ru/Al2O3 catalyst. The gas
product (dry basis) was mainly CH4 and CO2, while H2 production was quite low,
against expectations. Under the same operating conditions, the behavior of the
catalysts is quite different as the Ni catalyst promotes H2 production much more
than the Ru catalyst. A detailed discussion is provided on our results and those
of previous studies using the Ru/Al2O3 catalyst, thus acquiring more insight
into the catalyst behavior. The Ru catalyst showed a large increase in its
crystalline phase after testing, although the oxidation state of ruthenium did
not change.
Catalytic supercritical water gasification of primary paper sludge using a
homogeneous and heterogeneous catalyst: Experimental vs thermodynamic
equilibrium results
Bioresource Technology, Volume 201, February 2016, Pages 111-120
Jeanne Louw, Cara E. Schwarz, Andries J. Burger
Abstract
H2, CH4, CO and CO2 yields were measured during supercritical water gasification
(SCWG) of primary paper waste sludge (PWS) at 450 °C. Comparing these yields
with calculated thermodynamic equilibrium values offer an improved understanding
of conditions required to produce near-equilibrium yields. Experiments were
conducted at different catalyst loads (0–1 g/gPWS) and different reaction times
(15–120 min) in a batch reactor, using either K2CO3 or Ni/Al2O3–SiO2 as
catalyst. K2CO3 up to 1 g/gPWS increased the H2 yield significantly to 7.5
mol/kgPWS. However, these yields and composition were far from equilibrium
values, with carbon efficiency (CE) and energy recovery (ER) of only 29% and
20%, respectively. Addition of 0.5–1 g/gPWS Ni/Al2O3–SiO2 resulted in high H2
and CH4 yields (6.8 and 14.8 mol/kgPWS), CE of 84–90%, ER of 83% and a gas
composition relatively close to the equilibrium values (at hold times of 60–120
min).
Effect of oxygenated treatment on corrosion of the whole steam–water system in
supercritical power plant
Applied Thermal Engineering, Volume 93, 25 January 2016, Pages 1248-1253
Dongfang Jiang, Hong Xu, Bo Deng, Mengyuan Li, Zhuonan Xiao, Naiqiang Zhang
Abstract
The feedwater chemistry is critical to the overall corrosion and reliability of
the fossil fired generating units. The effect of dissolved oxygen on corrosion
of carbon steels in feedwater system is analyzed. The corrosion experiments of
boiler tube steels in supercritical water containing different dissolved oxygen
are carried out. The different effect mechanics of dissolved oxygen on corrosion
in different parts of steam–water system are defined. Flow accelerated corrosion
in low temperature feedwater system can be controlled by dissolved oxygen, but
dissolved oxygen can accelerate failure of boiler tubes at high temperature from
three aspects: corrosion rate, crack growth rate of SCC, and evaporating
consumption rate of chromium. Considering the corrosion of the whole steam–water
system, a more effective feedwater chemistry treatment method is proposed.
A comparative study of oxide scales grown on stainless steel and nickel-based
superalloys in ultra-high temperature supercritical water at 800 °C
Corrosion Science, Volume 106, May 2016, Pages 188-207
Yashar Behnamian, Amir Mostafaei, Alireza Kohandehghan, Babak Shalchi Amirkhiz,
Dominic Serate, Yifei Sun, Subiao Liu, Ermia Aghaie, Yimin Zeng, Markus
Chmielus, Wenyue Zheng, David Guzonas, Weixing Chen, Jing Li Luo
Abstract
This study investigates the oxidation behavior of several stainless steels and
nickel-based superalloys exposed to supercritical water at 800 °C for 12 h.
Characterization of the resulting oxide layers were conducted using weight
change measurements, X-ray diffraction, scanning/transmission electron
microscopy, and energy dispersive spectroscopy. Although the exposure time is
only 12 h, the thickness of the oxide layers formed was as high as 1 μm,
comprising different spinel structures. The influence of alloying elements such
as Al, Nb, Mo, Mn and Ti on the corrosion behavior is investigated and possible
corrosion mechanisms for each candidate alloy are discussed.
Oxidation of alloys for energy applications in
supercritical CO2 and H2O
Corrosion Science, In Press, Corrected Proof, Available online 19 March 2016
Gordon R. Holcomb, Casey Carney, Ömer N. Doğan
Abstract
To facilitate development of supercritical CO2 (sCO2) power plants, a comparison
of the oxidation behavior of austenitic stainless steels and Ni-base alloys in
sH2O and sCO2 were made. Experiments were conducted at 730 °C/207 bar (sCO2) and
726 °C/208 bar (sH2O). Ni-base alloys in sCO2 did not exhibit much change with
pressure. Ni-base alloys in sH2O had an increase in corrosion rate and the log
of the parabolic rate constant was proportional to pressure. Fine-grain
austenitic stainless steels in sCO2 and sH2O were both less protective with
pressure as the dense protective chromia scale was replaced with faster growing
Fe-oxide rich scales.
Supercritical water gasification of phenol using a Ru/CeO2 catalyst
Chemical Engineering Journal, Volume 283, 1 January 2016, Pages 358-365
Qingqing Guan, Xiaodian Huang, Jing Liu, Junjie Gu, Rongrong Miao, Qiuling Chen,
Ping Ning
Abstract
Phenols are typical aromatic pollutants and major byproducts of non-catalytic
gasification and liquefaction processes. In this work, Ru/CeO2 was prepared and
used to catalyze phenol gasification in supercritical water. The catalyst
improves carbon efficiency by about 90% at the conditions employed: 0.5 g
Ru/CeO2/g phenol catalyst loading at 550 °C with a water density of 0.0979 g/cm3
and a 5 wt% loading of phenol relative to water. This represents a more than
10-fold enhancement of carbon efficiency compared to the noncatalytic case, with
CH4 as the major gaseous product. GC–MS results show suppressed formation of
dimers, such as dibenzofuran and polycyclic aromatic hydrocarbons (PAHs), which
may be caused by the hydrogenation activity of Ru/CeO2. Kinetic modeling of the
gasification process gives an activation energy of 84.24 ± 22 kJ/mol and an
frequency factor (ln A) of 12.5 ± 2.9 for gaseous product formation, compared to
60 ± 17 kJ/mol and 7.53 ± 2.7 for char formation. Ru/CeO2 is stable in
supercritical water at temperatures up to 550 °C, suggesting that a Ru/CeO2
supercritical water gasification system may be a promising method for treating
phenols.
Hydrothermal conversion of Ulva macro algae in
supercritical water
The Journal of Supercritical Fluids, Volume 107, January 2016, Pages 182-188
Y. Graz, S. Bostyn, T. Richard, P. Escot Bocanegra, E. de Bilbao, J. Poirier, I.
Gokalp
Abstract
Ulva (Ulva armoricana and Ulva rotundata) are macro algae which are responsible
of environmental damages and are a cause of an eutrophication of the water in
the French coast (Mediterranean sea, Brittany). In this study, Ulva were
gasified in supercritical water in a batch reactor and in Hydrothermal Diamond
Anvil Cell apparatus. Experimental conditions evolve between 400 and 550 °C at
around 250 bar. Results show that a short time (7 min) in supercritical
condition is sufficient to obtain a significant conversion rate. H2 and CH4
concentrations exceed 15 mol.% at high temperature (550 °C) and high algae
concentrations are not favorable for H2 production. The solid residue represents
between 7 and 20 wt.% of the initial dry material and is mainly constituted of
carbon (20 wt.%) and inorganic compounds: salts (KCl, NaCl), CaSO4, SiO2 and
CaCO3. The very low dissolved organic carbon (DOC) values of the liquid residue
(<0.4 wt.%) confirm the high gasification rates. Thiophenes, pyridines, and
pyrazines were detected in the liquid phase. Hydrothermal Diamond Anvil Cell
(HDAC) experiments were performed to observe gasification stages at the
supercritical state.
The reproducibility of corrosion testing in supercritical water—Results of an
international interlaboratory comparison exercise
Corrosion Science, Volume 106, May 2016, Pages 147-156
D. Guzonas, S. Penttilä, W. Cook, W. Zheng, R. Novotny, A. Sáez-Maderuelo, J.
Kaneda
Abstract
A major challenge in supercritical water-cooled reactor development is the lack
of a consistent alloy database. An international interlaboratory comparison test
was organized to study the reproducibility of weight change data obtained for
identical alloys under similar conditions in different facilities. This paper
presents the test procedures, conditions, results, and additional
characterization data. More variation in weight change was observed than
expected. The scatter was small within the same laboratory, but large between
different laboratories. Much of this variation appears to be attributable to
differences in test facilities. The data generally agree on the relative ranking
of the corrosion resistance.
Conversion of brown coal continuously supplied into the reactor as coal–water
slurry in a supercritical water and water–oxygen mixture
The Journal of Supercritical Fluids, Volume 107, January 2016, Pages 707-714
Anatoly A. Vostrikov, Andrey V. Shishkin, Mikhail Ya. Sokol, Dmitriy Yu. Dubov,
Oxana N. Fedyaeva
Abstract
The results of a two-stage conversion of brown coal (gross-formula
CH0.96N0.01S0.002O0.31) in supercritical water (SCW) under isobaric conditions
(30 MPa) in the vertical tubular reactor of an original configuration are
presented. The first stage provides for a continuous supply of coal–water slurry
(CWS) into the reactor and discharging of the products with SCW into the
demountable samplers. The CWS composition was as follows (weight portions):
coal—100, water—125, and starch—2.25. It was found out that when increasing the
temperature of coal particles up to 600 °C during their falling down along the
reactor axis, the yields of volatile and liquid products were 25.4 and 27.5%,
respectively, relative to the weight of organic matter supplied into the
reactor. At the second stage of conversion, the SCW/O2 fluid was pumped through
a layer of coal particles accumulated at the reactor bottom during the first
stage. It was shown that as a result of heat emission during partial oxidation
of coal residue, the autothermal conditions for conversion were realized. The
yields of volatile combustible and liquid products at conversion in the SCW/O2
fluid were 25.1 and 3.4 wt.%, respectively. The increment of hydrogen in the
conversion products caused by water decomposition was equal to 20% relative to
the weight of hydrogen in initial coal.
Effect of supercritical water on the stability of WOX/TiO2 and NbOX/TiO2
catalysts during glycerol dehydration
The Journal of Supercritical Fluids, Volume 113, July 2016, Pages 158-165
Makoto Akizuki, Keiji Sano, Yoshito Oshima
Abstract
The catalytic stabilities of WOX/TiO2 (WTi) and NbOX/TiO2 (NbTi) during glycerol
dehydration in 400 °C supercritical water at 25 MPa and 33 MPa were
investigated. The effects of coking and active component leaching on catalytic
activities are quantitatively discussed. The catalytic activity of NbTi did not
decrease significantly with time at both pressures. At 25 MPa, the coke
precursors on the NbTi surface dissolved in the supercritical water because of
the middle-strength acidity of NbTi, thus preventing loss of catalytic
activities due to coking. At 33 MPa, coking was more suppressed, most likely
because the coke precursors were transferred from the catalyst pores more
effectively than at 25 MPa. Leaching of WOX from WTi occurred at the higher
reaction pressure due to high ion products of water, but leaching of Nb from
NbTi did not occur because of the high chemical stability of NbOX in acid/base
solutions.
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Analysis of supercritical water oxidation for detoxification of waste organic
solvent in university based on life cycle assessmentOriginal Research Article Journal of Hazardous Materials, Volume 194, 30 October 2011,
Pages 283-289
Yasunori Kikuchi, Kohjiro Kurata, Jun Nakatani, Masahiko Hirao, Yoshito Oshima Abstract Spray incineration and supercritical water oxidation (SCWO)
processes have been used for detoxifying waste organic fluids in the University
of Tokyo. In this study, we aim to elucidate the environmental aspects of these
waste treatment processes by life cycle assessment (LCA). Through the
investigation of actual plants, the inventory data and other characteristics of
actual plants were collected and analyzed. To confirm the potential of
SCWO, three modification types of the process and operation were
considered and assessed on the basis of estimated inventory data. The results
demonstrate that spray incineration has less environmental impact than
SCWO in all scenarios. However, SCWO has various
advantages for installation as a treatment process in universities such as
negligible risk of creating dioxins and particulate matter. Proper choice of the
treatment method for organic waste fluid requires a comprehensive analysis of
risks. Spray incineration poses the risk of providing dioxins and particulate
matter, while SCWO has such risk at negligible level.
This means that waste including concerned materials related to such emission
should be treated by SCWO. Using the right technologies
for the right tasks in the detoxification of hazardous materials should be
implemented for sustainable universities.
Analysis of the scale up of a transpiring wall reactor with a hydrothermal
flame as a heat source for the supercritical water oxidationOriginal Research Article The Journal of Supercritical Fluids, Volume 56, Issue 1,
February 2011, Pages 21-32
M.D. Bermejo, P. Cabeza, J.P.S. Queiroz, C. Jiménez, M.J. Cocero Abstract
Experimental data from a tubular reactor and from a transpiring wall reactor
(TWR) are used to analyze the scaling up of SCWO
reactors operating with a hydrothermal flame as a heat source. Results obtained
with the tubular reactor show that fluid velocity inside the reactor determines
the minimum injection temperature at which a stable hydrothermal flame is
formed. When the fluid velocity inside of the reactor is lower, the extinction
temperature of the hydrothermal flame in that reactor is also lower. Using this
reactor, extinction temperatures are always near or above the critical
temperature of water. Total TOC removals are possible working with
isopropyl-alcohol at temperatures between 650 and 700 °C and residence times of
0.5 s. Results of the TWR show that steady operation with a hydrothermal flame
inside is possible even when reagents are injected at subcritical conditions as
low as 170 °C. Temperature measurements show that reaction is not initiated in
the injector but in the reaction chamber, where fluid velocity is lower than 0.1
s. This was explained by estimating that the flame front velocity of a
hydrothermal flame is of the order of 0.1 m/s. Thus, it is expected that the
flame is stabilized in the reaction chamber and not in the injector, where fluid
velocities are higher than 2 m/s. A previously developed model of the TWR was
modified in order to describe the ignition in the reaction chamber and not in
the injector. The model reproduces satisfactorily experimental data and it was
used to propose the design of scaled up reactors for SCWO
with a hydrothermal flame inside.
Supercritical water oxidation of coal: Investigation of operating parameters'
effects, reaction kinetics and mechanismOriginal
Research Article Fuel Processing Technology, Volume 92, Issue 3, March 2011,
Pages 291-297
Shuzhong Wang, Yang Guo, Liang Wang, Yuzhen Wang, Donghai Xu, Honghe Ma Abstract
Supercritical water oxidation (SCWO) of coal was
conducted in a continuous tubular reactor under various reaction conditions. Our
experimental results show that the removal rate of chemical oxygen demand (COD)
had no significant dependence on the temperature variations. Effect of residence
time was less significant as exceeded fixed values. Free radical mechanism of
SCWO reaction may be a possible explanation for the relative low
conversion rate of coal at the range of tested oxygen excess. Compared with
other parameters, effect of pressure was less significant. A global power-law
rate expression was regressed from experimental data. The reaction orders for
coal slurry and oxidant were 1.79 and 0.28 respectively. The reaction activation
energy Ea was determined to be 112.3 kJ mol−1, and
the pre-exponential factor k0 was 412 (mol/L)−1.07
s−1. The deviation between the model and experimental data was within
± 9%. Free radical mechanism, oxidation and hydrolysis mechanisms and phenolic
hydroxyl oxidation mechanism were considered to be the possible mechanisms for
the SCWO process of coal.
Water density effects on methanol oxidation in supercritical water at high
pressure up to 100 MPaOriginal Research
Article The Journal of Supercritical Fluids, Volume 58, Issue 1, August
2011, Pages 142-149
Tatsuya Fujii, Rumiko Hayashi, Shin-ichiro Kawasaki, Akira Suzuki, Yoshito
Oshima Abstract
Reaction kinetics of methanol oxidation in supercritical water at high pressure
condition (420 °C; 34–100 MPa; ρ = 300–660 kg/m3) was
investigated. Pseudo-first order rate constant for methanol decomposition
increased with increasing water density. Effects of supercritical water on the
reaction kinetics were investigated using a detailed chemical kinetics model.
Incorporating the effect of diffusion in a reduced model revealed that overall
kinetics for SCWO of methanol is not diffusion-limited.
Roles of water as a reactant were also investigated. The dependence of
sensitivity coefficient for methanol concentration and rate of production of OH
radical on water density indicated that a reaction, HO2 + H2O
= OH + H2O2, enhanced the OH radical production and
thereby facilitated the decomposition of methanol. It is presumed that
concentration of key radicals could be controlled by varying pressure
intensively.
Pathways and kinetics of partial oxidation of phenol in supercritical waterOriginal Research Article Chemical Engineering Journal, Volume 175, 15 November 2011,
Pages 201-206
Qingqing Guan, Chaohai Wei, Xin-Sheng Chai Abstract This study reports on the pathways and kinetics of individual gaseous
species involved in the partial oxidation of phenol in supercritical water. The
pathway is a combination of supercritical water oxidation (SCWO)
and supercritical water gasification (SCWG) processes. A kinetic model that
involves oxygen is proposed that fits the experimental data and accurately
predicts the effects of the O/phenol ratio on the decomposition of phenol.
Specifically, at lower O/Phenol ratios, the gasification of acids and the water
gas shift reaction predominated, increasing the amount of H2 in the
gaseous products. At higher O/Phenol ratios, on the other hand, the oxidation of
acid intermediates and CO oxidation predominated, thereby increasing the amount
of CO2, while H2 decreased.
Experimental study of hydrothermal flames formation using a tubular injector
in a refrigerated reaction chamber. Influence of the operational and geometrical
parametersOriginal Research Article The Journal of Supercritical Fluids, Volume 59, November 2011,
Pages 140-148 M.D. Bermejo, C. Jiménez, P. Cabeza, A.
Matías-Gago, M.J. Cocero Abstract
Experimental results using three different empty tubular injectors into a
refrigerated reaction chamber containing a hydrothermal flame as an internal
heat source are presented. In the supercritical water oxidation process, one
method of avoiding external preheating is injecting the feed at room temperature
into a hydrothermal flame. In this way, plugging and corrosion problems produced
during transition from subcritical to supercritical conditions in the preheating
system can be avoided. The influence of feed flow, injection temperature and
diameter and length of the injector has been evaluated by studying the
temperature profiles along the reactor, the total organic carbon (TOC) removal
and the extinction temperatures at different conditions. It was possible to
inject reactants even at room temperature into the hydrothermal flame with
organic destruction efficiencies higher than 99.9%, presenting better
operational results than other reactors constructed by our research work. The
effect of salt addition under subcritical conditions in a hydrothermal flame was
also studied. Feeds containing up to 2.5 wt% Na2SO4 could
be injected in the reactor without plugging problems and a TOC removal of 99.7%
was achieved in these conditions. However, only about 10% of the salt introduced
in the reactor could be recovered.
Hydrothermal liquefaction of biomass: A review of subcritical water
technologiesReview Article Energy, Volume 36, Issue 5, May 2011, Pages 2328-2342
Saqib Sohail Toor, Lasse Rosendahl, Andreas Rudolf Abstract
This article reviews the hydrothermal liquefaction of biomass with the aim of
describing the current status of the technology. Hydrothermal liquefaction is a
medium-temperature, high-pressure thermochemical process, which produces a
liquid product, often called bio-oil or bi-crude. During the hydrothermal
liquefaction process, the macromolecules of the biomass are first hydrolyzed
and/or degraded into smaller molecules. Many of the produced molecules are
unstable and reactive and can recombine into larger ones. During this process, a
substantial part of the oxygen in the biomass is removed by dehydration or
decarboxylation. The chemical properties of bio-oil are highly dependent of the
biomass substrate composition. Biomass constitutes of various components such as
protein; carbohydrates, lignin and fat, and each of them produce distinct
spectra of compounds during hydrothermal liquefaction. In spite of the potential
for hydrothermal production of renewable fuels, only a few hydrothermal
technologies have so far gone beyond lab- or bench-scale.
Penetration length studies of supercritical water jets submerged in a
subcritical water environment using a novel optical Schlieren methodOriginal Research Article The Journal of Supercritical Fluids, Volume 57, Issue 2, June
2011, Pages 175-182
Tobias Rothenfluh, Martin J. Schuler, Philipp Rudolf von Rohr Abstract
In hydrothermal spallation deep drilling a high-velocity, hot, supercritical
water jet is directed towards the rock to induce fragmentation. One major
challenge in the realization of this novel technique is the entrainment of
comparatively cool, aqueous drilling fluid by the hot water jet, which can lead
to significant heat losses before the hot jet's energy can be transferred to the
rock. The present work quantifies such entrainment effects by determining
penetration lengths of supercritical water jets injected into a cool,
subcritical environment using a novel optical Schlieren method. Penetration
lengths of supercritical jets were found to be equal to the injector's nozzle
diameter and almost independent of the jet's temperature at the nozzle exit and
the jet's mass flow under almost all experimental conditions investigated. A
semi-empirical model adapted from steam jet studies confirmed these findings and
indicates that heat and mass transfer are primarily controlled by turbulent
mixing.
Hydrogen production from bioethanol reforming in supercritical waterOriginal Research Article The Journal of Supercritical Fluids, Volume 57, Issue 1, May
2011, Pages 58-65
Supaporn Therdthianwong, Nawadee Srisiriwat, Apichai Therdthianwong, Eric
Croiset Abstract
Hydrogen production by reforming and oxidative reforming of ethanol in
supercritical water (SCW) at the intermediate temperature range of 500–600 °C
and pressure of 25 MPa were investigated at different ethanol concentrations or
water to ethanol ratios (3, 20 and 30), with the absence and the presence of
oxygen (oxygen to ethanol ratio between 0 and 0.156). Hydrogen was the main
product accompanied with relatively low amounts of carbon dioxide, methane and
carbon monoxide. Some liquid products, such as acetaldehyde and, occasionally,
methanol were present. The ethanol conversion and hydrogen yield and selectivity
increased substantially as the water to ethanol ratio and the reaction
temperature increased. Ethanol was almost completely reformed and mainly
converted to hydrogen giving a H2/CO ratio of 2.6 at 550 °C and water
to ethanol ratio of 30 without carbon formation. Coke deposition was favored at
low water to ethanol ratio, especially at high temperatures (≥550 °C). The
hydrogen yield improved as the ethanol was partially oxidized by the oxygen
added into the feed at oxygen to ethanol ratios <0.071. It was evidenced that
the metal components in Inconel 625 reactor wall reduced by a hydrogen stream
acted as a catalyst promoting hydrocarbon reforming as well as water–gas-shift
reactions while dehydrogenation of ethanol forming acetaldehyde can proceed
homogeneously under the SCW condition. However, at high oxygen to ethanol ratio,
the reactor wall was gradually deactivated after being exposed to the oxidant in
the feed. The loss of the catalytic activity of the reactor surface was mainly
due to the metal oxide formation resulting in reduction of catalytic activity of
the reactor wall and reforming of carbon species was no longer promoted.
Supercritical water oxidation of Ion Exchange Resins in a stirred reactor:
Numerical modellingOriginal Research Article Chemical Engineering Science, In Press,
Corrected Proof, Available online 17 October 2011
A. Leybros, A. Roubaud, P. Guichardon, O. Boutin Abstract Supercritical water oxidation offers a viable alternative treatment to
destroy the organic structure of Ion Exchange Resins. In order to design and
define appropriate dimensions for the supercritical oxidation reactor, a 2D
simulation of the fluid dynamics and heat transfer during the oxidation process
has been investigated. The solver used is a commercial code, Fluent®
6.3. The turbulent flow field in the reactor, created by the stirrer is taken
into account with a k−ω model and a swirl imposed to the fluid.
Particle trajectories are modelled with the Discrete Random Walk Particle Model.
For the solubilization of the particles in supercritical water, a mechanism has
been proposed and implemented into Fluent® software through the Eddy
Dissipation Concept approach, taking into account the identified rate
determining species. Simulation results provide results on the flow, temperature
fields and oxidation localization inside the reactor. For the reactive
particles-supercritical water flow model, the effect of parameters, such as feed
flow rates or stirring velocity, can be focussed. Reaction temperature is
predicted with deviation lower than 15%. Degradation conversions are in good
agreement with experimental ones.
Hydrothermal liquefaction of biomass: A review of subcritical water
technologiesReview Article Energy, Volume 36, Issue 5, May 2011, Pages 2328-2342
Saqib Sohail Toor, Lasse Rosendahl, Andreas Rudolf Abstract This article reviews the hydrothermal liquefaction of biomass with the
aim of describing the current status of the technology. Hydrothermal
liquefaction is a medium-temperature, high-pressure thermochemical process,
which produces a liquid product, often called bio-oil or bi-crude. During the
hydrothermal liquefaction process, the macromolecules of the biomass are first
hydrolyzed and/or degraded into smaller molecules. Many of the produced
molecules are unstable and reactive and can recombine into larger ones. During
this process, a substantial part of the oxygen in the biomass is removed by
dehydration or decarboxylation. The chemical properties of bio-oil are highly
dependent of the biomass substrate composition. Biomass constitutes of various
components such as protein; carbohydrates, lignin and fat, and each of them
produce distinct spectra of compounds during hydrothermal liquefaction. In spite
of the potential for hydrothermal production of renewable fuels, only a few
hydrothermal technologies have so far gone beyond lab- or bench-scale.
Evolution of naphthalene and its intermediates during oxidation in
subcritical/supercritical waterOriginal
Research Article Proceedings of the Combustion Institute, Volume 33, Issue 2,
2011, Pages 3185-3194
Sikun Xu, Ian Butler, Iskender Gökalp, Janusz A. Kozinski Abstract
Oxidation of naphthalene (Nap) in supercritical water (SCW) was carried out in a
batch reactor (6-ml volume) up to 400 °C and 300 atm (maximum residence time of
1800 s). Two systems were studied. System A consisted of pure naphthalene mixed
with oxygen and water: 0.065 M Nap + 1.441 M O2 + 8.549 M H2O.
System B included, in addition to O2 and H2O, a heavy
metal and an ash to simulate their roles in the destruction of Nap: 0.065 M Nap
+ 1.441 M O2 + 0.008 M Cr(NO3)3 + 0.065 M Al2Si2O5·(OH)4
+ 8.624 M H2O. It was shown that, in general, the oxidation process
can be divided into three stages characterized by H2O2
decomposition to H2O and O2 (Stage 1), oxidation in
saturated/subcritical water up to 360 °C and 225 atm (Stage 2), and fast
oxidation in the supercritical region (Stage 3). The oxidation process revealed
different reaction rates in different systems. Relatively low activation energy
of 10–30 kJ/mol was obtained below 360 °C and 225 atm in the System A and in the
whole temperature range in the System B. High activation energy (139.5 kJ/mol)
was obtained for supercritical water oxidation of naphthalene in the System A.
The catalytic effect of Cr3+/ash stimulated naphthalene oxidation.
Time-resolved yields of major products and intermediates were obtained. The
reaction pattern was proposed. It describes the evolution of naphthalene and
intermediates as a sequence of reactions comprising transformations of the main
compounds and their inter-conversion. This radical-involving reaction mechanism
is mainly based on the quantification of the profiles of the intermediates.
Destruction of methylphosphonic acid in a supercritical water oxidation
bench-scale double wall reactorOriginal Research Article Journal of Environmental Sciences, Volume 23, Issue 4, April
2011, Pages 545-552
Bambang Veriansyah, Eun-Seok Song, Jae-Duck Kim Abstract
The destruction of methylphosphonic acid (MPA), a final product by
hydrolysis/neutralization of organophosphorus agents such as sarin and VX
(O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothionate), was
investigated in a a bench-scale, continuous concentric vertical double wall
reactor under supercritical water oxidation condition. The experiments were
conducted at a temperature range of 450-600°C and a fixed pressure of 25 MPa.
Hydrogen peroxide was used as an oxidant. The destruction efficiency (DE) was
monitored by analyzing total organic carbon (TOC) and MPA concentrations using
ion chromatography on the liquid effluent samples. The results showed that the
DE of MPA up to 99.999% was achieved at a reaction temperature of 600°C, oxygen
concentration of 113% storichiometric requirement, and reactor residence time of
8 sec. On the basis of the data derived from experiments, a global kinetic rate
equation for the DE of MPA and DE of TOC were developed by nonlinear regression
analysis. The model predictions agreed well with the experimental data.
Exploration of the effect of process variables on the production of
high-value fuel gas from glucose via supercritical water gasificationOriginal Research Article Bioresource Technology, Volume 102, Issue 3, February 2011,
Pages 3480-3487
Doug Hendry, Chandrasekar Venkitasamy, Nikolas Wilkinson, William Jacoby Abstract
A new continuous supercritical water gasification reactor was designed to
investigate glucose gasification in supercritical water at high temperatures and
low residence times. A 23 full factorial experiment was performed to
determine the effects of feed concentration, temperature, and residence time on
glucose gasification. The temperature levels (750 °C and 800 °C) were higher
than ever used, while the residence times (4 and 6.5 s) were shorter than ever
used in previous supercritical water gasification studies. The reactor proved
capable of attaining higher gasification rates than previously shown with high
efficiencies and yields. In addition, the glucose gasification reaction was
modeled by estimating activation energy and reaction order of glucose
gasification in supercritical water.
Continuous salt precipitation and separation from supercritical water. Part
3: Interesting effects in processing type 2 salt mixturesOriginal Research Article The Journal of Supercritical Fluids, In
Press, Corrected Proof, Available online 2 September 2011
Martin Schubert, John Aubert, Johannes B. Müller, Frédéric Vogel Abstract
Using a modified continuously operated laboratory plant which had been
constructed in our group to visualize the salt separation from supercritical
water using neutron radiography we investigated the continuous salt separation
and recovery from supercritical water for four different ternary salt and water
mixtures containing either a type 1 and a type 2 salt or a mixture of two type 2
salts.
As the mixture of Na3PO4/K2SO4 (both
type 2 salts) may form a mixture of K3PO4/Na2SO4
(type 1/type 2) by permutation of the ions during precipitation from
supercritical water, the separation performance of the K3PO4/Na2SO4
mixture containing the same concentration in sodium, potassium, sulfate, and
phosphate as the Na3PO4/K2SO4
mixture was investigated as well. Both mixtures showed the same trend in the
separation performance exhibiting a maximum in the separation efficiency in the
temperature range studied, and showing a preferential separation of sodium and
phosphate or potassium and sulfate ions depending on the temperature of the
separator vessel.
The mixtures of Na3PO4/Na2SO4 and Na2SO4/K2SO4
were “real type 2 salt mixtures”, i.e. mixtures in which the permutation of the
ions does not lead to the formation of a type 1 salt in the respective mixture.
The salts from the Na3PO4/Na2SO4
mixture could not be recovered as a concentrated brine. This salt mixture
behaved as would be expected for the respective single type 2 salt solutions of
either Na3PO4 or Na2SO4.
Interestingly, a concentrated brine could be recovered for the Na2SO4/K2SO4
mixture with the salt recovery in the brine effluent showing a maximum at a
separator setpoint temperature of 450–460 °C. Beyond this temperature the salt
mixture became “sticky”, thus exhibiting the behavior as would be expected for a
type 2 salt mixture.
Partial oxidative gasification of phenol for hydrogen in supercritical waterOriginal Research Article Applied Energy, Volume 88, Issue 8, August 2011, Pages
2612-2616
Qingqing Guan, Chaohai Wei, Huashun Shi, Chaofei Wu, Xin-Sheng Chai Abstract
The paper reports partial oxidative gasification of phenol for hydrogen in
supercritical water (SCW) at lower temperature (<753 K), at which cleavages of
aromatic ring occur difficultly and tend to undesirable polymerization. The
results showed that O2 is effective to gasification of phenol in SCW.
∼76% of phenol was gasified and 2.7
mol/mol of hydrogen was produced within 180 s with Na2CO3
as catalyst at the selected process conditions, a molar ratio of
oxygen-to-phenol, 7.5–1, 723 K, and 24 MPa. It was found that unstable
opening-rings products oxalic and maleic acid and stable dimmerization compounds
in liquid water were formed during partial oxidation process. The process also
indicated phenol was rapidly converted, and some opening-rings products were
slowly gasified, which also confirmed oxygen served as effective reactant for
ring-opening. Based on the given reaction conditions, a treatment process using
a real wastewater from coking industry was performed. The data showed that the
present technology provides an effective way to gasification of phenol
wastewater for high-value energy utilization.
Green chemical processes with supercritical fluids: Properties, materials,
separations and energyOriginal
Research Article The Journal of Supercritical Fluids, Volume 60, December 2011,
Pages 2-15
Hiroshi Machida, Masafumi Takesue, Richard L. Smith Jr. Abstract
In this work, an overview of the properties of supercritical fluids is given on
using water and carbon dioxide for developing green chemical processes. Present
industrial processes and emerging technologies that use supercritical fluids are
highlighted. Supercritical fluids are being used in transcritical cycles for
heat transfer due to their favorable thermophysical properties and their
environmental compatibility. Supercritical water is being proposed as a reaction
solvent for zinc silicate industrial phosphors, since it allows production of
luminescent materials at low temperatures (400 °C) and with less energy than
industrial solid-state methods that require high temperatures (1200 °C).
Supercritical CO2–ionic liquid systems have much potential as
biphasic systems for reactions and separations, however, when used for chiral
separations, the selectivity of these systems is not well understood yet. The
use of supercritical CO2 for viscosity reduction in ionic liquid
reaction systems seems to be a favorable research area with conversion of
d-fructose to
5-hydroxymethylfurfural in high yields (>90%) being an example. Systems to
convert biomass to energy by direct oxidation in supercritical water are under
development. Many opportunities exist for developing green chemical processes
with supercritical fluids.
Closing the phosphorus loop in England: The spatio-temporal balance of
phosphorus capture from manure versus crop demand for fertiliserOriginal Research Article Resources, Conservation and Recycling, Volume 55, Issue 12,
October 2011, Pages 1146-1153
Anna Bateman, Dan van der Horst, David Boardman, Arun Kansal, Cynthia
Carliell-Marquet Abstract Every year 90 million tonnes of housed livestock manures are produced in
the UK. This is a valuable reservoir of global phosphorus (P) and a point in the
cycle where it is vulnerable to being lost from the terrestrial system. Improved
manure management for the effective reuse of phosphorus is vital to
simultaneously tackle a major source of water pollution and reduce our
dependence on imported fertilisers. This paper quantifies, for the first time,
the spatial and temporal challenges of recycling the required amount of manure P
from areas of livestock production to areas of crop production in eight regions
of England. The analysis shows that England has a P deficit and therefore the
capacity to fully utilise the manure P on arable land, but that uneven spatial
distribution of livestock poses a significant challenge to closing the P loop in
agriculture. Two of the eight regions were shown to have surplus manure P, with
the remaining six regions having P deficits, indicating that an annual export of
4.7 thousand tonnes P (2.8 million tonnes manure) must take place from the west
to the east of the country each year to balance P supply and demand. Moreover,
housed manure production peaks between October and February, requiring an excess
of 23.0 thousand tonnes P (15 million tonnes manure) to be stored until it can
be used for crop fertilisation from March onwards. The results demonstrate the
scale of the challenge in managing manure P in an agricultural system that has
separated livestock production from crop production, a pattern that is echoed
throughout the developed world. To overcome the spatial and temporal challenges,
a logistical system is recommended that will balance the nutrient potential
(nitrogen and P content and availability) and pollution potential (eutrophication,
greenhouse gas emissions, particulates and nitrous oxide from transport) for
cost-effective and environmentally compatible redistribution of manure P from
areas of surplus to areas of deficit, when required.
Evolution of naphthalene and its intermediates during oxidation in
subcritical/supercritical waterOriginal
Research Article Proceedings of the Combustion Institute, Volume 33, Issue 2,
2011, Pages 3185-3194
Sikun Xu, Ian Butler, Iskender Gökalp, Janusz A. Kozinski Abstract
Oxidation of naphthalene (Nap) in supercritical water (SCW) was carried out in a
batch reactor (6-ml volume) up to 400 °C and 300 atm (maximum residence time of
1800 s). Two systems were studied. System A consisted of pure naphthalene mixed
with oxygen and water: 0.065 M Nap + 1.441 M O2 + 8.549 M H2O.
System B included, in addition to O2 and H2O, a heavy
metal and an ash to simulate their roles in the destruction of Nap: 0.065 M Nap
+ 1.441 M O2 + 0.008 M Cr(NO3)3 + 0.065 M Al2Si2O5·(OH)4
+ 8.624 M H2O. It was shown that, in general, the oxidation process
can be divided into three stages characterized by H2O2
decomposition to H2O and O2 (Stage 1), oxidation in
saturated/subcritical water up to 360 °C and 225 atm (Stage 2), and fast
oxidation in the supercritical region (Stage 3). The oxidation process revealed
different reaction rates in different systems. Relatively low activation energy
of 10–30 kJ/mol was obtained below 360 °C and 225 atm in the System A and in the
whole temperature range in the System B. High activation energy (139.5 kJ/mol)
was obtained for supercritical water oxidation of naphthalene in the System A.
The catalytic effect of Cr3+/ash stimulated naphthalene oxidation.
Time-resolved yields of major products and intermediates were obtained. The
reaction pattern was proposed. It describes the evolution of naphthalene and
intermediates as a sequence of reactions comprising transformations of the main
compounds and their inter-conversion. This radical-involving reaction mechanism
is mainly based on the quantification of the profiles of the intermediates.
Destruction of methylphosphonic acid in a supercritical water oxidation
bench-scale double wall reactorOriginal Research Article Journal of Environmental Sciences, Volume 23, Issue 4, April
2011, Pages 545-552
Bambang Veriansyah, Eun-Seok Song, Jae-Duck Kim Abstract
The destruction of methylphosphonic acid (MPA), a final product by
hydrolysis/neutralization of organophosphorus agents such as sarin and VX
(O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothionate), was
investigated in a a bench-scale, continuous concentric vertical double wall
reactor under supercritical water oxidation condition. The experiments were
conducted at a temperature range of 450-600°C and a fixed pressure of 25 MPa.
Hydrogen peroxide was used as an oxidant. The destruction efficiency (DE) was
monitored by analyzing total organic carbon (TOC) and MPA concentrations using
ion chromatography on the liquid effluent samples. The results showed that the
DE of MPA up to 99.999% was achieved at a reaction temperature of 600°C, oxygen
concentration of 113% storichiometric requirement, and reactor residence time of
8 sec. On the basis of the data derived from experiments, a global kinetic rate
equation for the DE of MPA and DE of TOC were developed by nonlinear regression
analysis. The model predictions agreed well with the experimental data.
Hydration of OH radical in high temperature waterOriginal Research Article Journal of Molecular Liquids, Volume 164, Issues 1-2, 1
November 2011, Pages 34-38
J. Szala-Bilnik, D. Swiatla-Wojcik Abstract
Molecular dynamics simulation study on the hydration and hydrogen-bonding of the
OH radical is presented for the 25 MPa isobar and the temperature ranging from
373 to 673 K. For the first time the water molecule and the radical have been
described by the flexible three- and two-site models, respectively, which
account for short-range interaction of the hydrogen atom. We have found that the
mechanism of hydration and the degree of radical–water hydrogen-bonding are
closely related to the structural transformations occurring in the
hydrogen-bonded network of the solvent. Compact and ordered network, typical for
the liquid phase, favours the cavity localization. Up to 573 K the decrease in
the number of water–water hydrogen bonds has been associated with the increase
in the number of radical–water H-bonds. Unlike the hydration in the condensed
liquid phase the low density of supercritical water at 673 K stimulates the
radical behaviour as a structure-maker. In the presence of OH the structural
inhomogeneity of the solvent has been noticeably reduced. Our work showed the
importance of short-range interaction of hydrogen atoms in hydration and
hydrogen bonding of OH at high temperatures and proved that neglect of the
angular condition greatly overestimates the number of radical–water H-bonds,
mostly of the H-acceptor type.
A review on process conditions for optimum bio-oil yield in hydrothermal
liquefaction of biomassReview
Article Renewable and Sustainable Energy Reviews, Volume 15, Issue 3,
April 2011, Pages 1615-1624
Javaid Akhtar, Nor Aishah Saidina Amin Abstract Hydrothermal liquefaction is a technique for obtaining clean biofuel from
biomass in the presence of a solvent at moderate to high temperature (250–550
°C) and pressure (5–25 MPa). Hydrothermal decomposition of biomass leads to the
formation of various compounds depending upon operating parameters. The role of
processing conditions including final liquefaction temperature, residence times,
rate of biomass heating, size of biomass particles, type of solvent media and
hydrogen donor solvents is important for the bio-oil yield and quality of the
product. The effect of these parameters on the yield and composition of the
liquid products is reviewed in the paper. A brief description about the
decomposition mechanism is also included to highlight the product types during
hydrothermal liquefaction.
Hydrothermal gasification of olive mill wastewater as a biomass source in
supercritical waterOriginal Research Article The Journal of Supercritical Fluids, Volume 57, Issue 1, May
2011, Pages 50-57
Ekin Kıpçak, Onur Ö. Söğüt, Mesut Akgün Abstract In this study, the hydrothermal gasification of biomass in supercritical
water is investigated. The work is of peculiar value since a real biomass, olive
mill wastewater (OMW), is used instead of model biomass compounds. OMW is a
by-product obtained during olive oil production, which has a complex nature
characterized by a high content of organic compounds and polyphenols. The high
content of organics makes OMW a desirable biomass candidate as an energy source.
The hydrothermal gasification experiments for OMW were conducted with five
different reaction temperatures (400, 450, 500, 550 and 600 °C) and five
different reaction times (30, 60, 90, 120 and 150 s), under a pressure of 25 MPa.
The gaseous products are mainly composed of hydrogen, carbon dioxide, carbon
monoxide and C1–C4 hydrocarbons, such as
methane, ethane, propane and propylene. Maximum amount of the gas product
obtained is 7.71 mL per mL OMW at a reaction temperature of 550 °C, with a
reaction time of 30 s. The gas product composition is 9.23% for hydrogen, 34.84%
for methane, 4.04% for ethane, 0.84% for propane, 0.83% for propylene, 49.34%
for carbon dioxide, and 0.88% for minor components such as n-butane,
i-butane, 1-butene, i-butene, t-2-butene,
1,3-butadiene and nitrogen at this reaction conditions.
Supercritical water gasification of an aqueous by-product from biomass
hydrothermal liquefaction with novel Ru modified Ni catalystsOriginal Research Article Bioresource Technology, Volume 102, Issue 17, September 2011,
Pages 8279-8287
Linghong Zhang, Pascale Champagne, Chunbao (Charles) Xu Abstract
Supercritical water gasification (SCWG) of glucose solution (50–200 g/L), a
simulated aqueous organic waste (composed of glucose, acetic acid and guaiacol)
and a real aqueous organic waste stream generated from a sludge hydrothermal
liquefaction process was performed in a bench-scale continuous down-flow tubular
reactor with novel 0.1RuNi/γ-Al2O3 or
0.1RuNi/activated carbon (AC) catalyst (10 wt.% Ni with a Ru-to-Ni molar ratio
of 0.1). 0.1RuNi/γ-Al2O3 was very
effective in catalyzing SCWG of glucose solution and the simulated aqueous
organic waste, attaining an H2 yield of 53.9 mol/kg dried
feedstock at 750 °C, 24 MPa and a WHSV of 6 h−1. However,
the γ-Al2O3-supported catalyst was not
resistant to the attack of alkali and nitrogen compounds in the real waste
during the SCWG of the real aqueous organic waste, whereas the AC-based catalyst
exhibited higher stability. This research provides a promising approach to the
treatment and valorization of aqueous organic waste via SCWG.
The behavior of phosphorus in sub- and super-critical water gasification of
sewage sludgeOriginal Research Article Chemical Engineering Journal, Volume 171, Issue 1, 15 June 2011,
Pages 190-196
W. Zhu, Z.R. Xu, L. Li, C. He Abstract
In this study, the behavior of phosphorus (P) during the non-catalytic sub- and
supercritical water gasification of dewatered sewage sludge was investigated
using a high-pressure autoclave. Various operating parameters such as reaction
temperature, pressure and residence time were varied to investigate their
effects on the P behaviors. The results supported that the majority of P
migrated into the solid residue since the concentration of total P in the solid
residue showed a significant increase (up to 20 mg-P/g). In addition, the
organic P in the sludge was almost completely converted into phosphate during
supercritical water gasification. A significant proportion of P remained in
aqueous phase was dissoluble reactive P, which was dominated of HPO42−.
Supercritical water oxidation of phenol with air. Experimental results and
modellingOriginal Research Article Chemical Engineering Journal, Volume 152, Issue 1, 1 October
2009, Pages 227-233
A. Fourcault, B. García-Jarana, J. Sánchez-Oneto, F. Marias, J.R. Portela Abstract
Hydrothermal oxidation is an efficient and clean way for the treatment of
wastewater containing organic matter. Because of its specific properties,
supercritical water ensures high conversion of a wide range of organic load in
the presence of an oxidant. The purpose of this work is to develop a
mathematical model for a continuous flow tubular reactor devoted to hydrothermal
oxidation. This reactor has a low ratio diameter length with one air injection.
The mathematical model is based on plug flow assumption. The governing equations
are: momentum, mass, species and energy balances. According to this model, the
profiles of temperature and concentration of chemical species are computed along
the reactor. The numerical predictions of the model are compared to experimental
profiles obtained in the case of supercritical oxidation of phenol. These
comparisons show very good agreement.
Investigation of thermochemical conversion of biomass in supercritical water
using a batch reactorOriginal Research Article Fuel, Volume 90, Issue 8, August 2011, Pages 2662-2670
Chandrasekar Venkitasamy, Doug Hendry, Nikolas Wilkinson, Lakdas Fernando,
William A. Jacoby Abstract
This study focused on gasification of biomass and a biomass model compound. Data
are presented that show the presence of supercritical water enhances
gasification efficiency, as it participates as both a solvent and a reactant. It
is established that biomass gasification efficiencies are in the same range for
all types of biomass. The thermodynamic changes of state are functions of
elemental composition, not biomass species. The oxidation state of carbon atom
of biomass is a key variable in determining the changes in enthalpy during both
conventional combustion and supercritical water gasification. The oxidation
state of the feed (together with the reaction conditions that influence the
degree to which water participates as a reactant) also determines the vapor
product composition.
Decomposition reactions to vapor products are rapid and complete at high
temperature (⩾550 °C), catalytic mediation is not required. Temperature and
residence time are important operating parameters for SCW gasification. Less
important are the pressure of gasification (in the range of 40–67 MPa) and the
presence of catalyst. The vapor yield, gas composition, the carbon and hydrogen
balance of SCW gasification are functions of gasification temperature, residence
time and biomass load (concentration).
Destruction of chemical agent simulants in a supercritical water oxidation
bench-scale reactorOriginal Research Article Journal of Hazardous Materials, Volume 147, Issues 1-2, 17
August 2007, Pages 8-14
Bambang Veriansyah, Jae-Duck Kim, Jong-Chol Lee Abstract In this
paper, ammonia as an important ingredient in landfill leachate was mainly
studied. Based on Peng–Robinson formulations and Gibbs free energy minimization
method, the estimation of equilibrium composition and thermodynamic analysis for
supercritical water oxidation of ammonia (SCWO) was
made. As equilibrium is reached, ammonia could be totally oxidized in SCW. N2
is the main product, and the formation of NO2 and NO could be
neglected. The investigation on SCWO of landfill
leachate was conducted in a batch reactor at temperature of 380–500 °C, reaction
time of 50–300 s and pressure of 25 MPa. The effect of reaction parameters such
as oxidant equivalent ratio, reaction time and temperature were investigated.
The results showed that COD and NH3 conversion improved as
temperature, reaction time and oxygen excess increased. Compared to organics, NH3
is a refractory compound in supercritical water. The conversion of COD and NH3
were higher in the presence of MnO2 than that without catalyst. The
interaction between reaction temperature and time was analyzed by using response
surface method (RSM) and the results showed that its influence on the NH3
conversion was relatively insignificant in the case without catalyst. A global
power-law rate expression was regressed from experimental data to estimate the
reaction rate of NH3. The activation energy with and without catalyst
for NH3 oxidation were 107.07 ± 8.57 kJ/mol and 83.22 ± 15.62 kJ/mol,
respectively.
1.
Operating
characteristics of a transpiring-wall SCWO reactor with a hydrothermal
flame as internal heat source Wellig, B. / Lieball, K. / Rudolf von Rohr, Ph., Jnl. of
Supercritical Fluids, May 2005
...Fig. 5 Schematic representation of the SCWO pilot plant. FI:
flow indication, PI: pressure...Operating characteristics of a
transpiring-wall SCWO reactor with a hydrothermal flame as
internal...A novel supercritical water oxidation (SCWO) system with
a transpiring-wall reactor...
2.
Supercritical
water oxidation improvements through chemical reactors energy integration Lavric, E.D. / Weyten, H. / De Ruyck, J. / Plesu, V. / Lavric, V., Applied
Thermal Engineering, Sep 2006
...Abstract Supercritical Water Oxidation (SCWO) is the process of
complete destruction...complete oxidation. Typical products from a SCWO
process include carbon dioxide, water, and inorganic salts or acids. SCWO
advantages include very high destruction...
Phosphorus
release from ash, dried sludge and sludge residue from supercritical water
oxidation by acid or base Stark, K. / Plaza, E. / Hultman, B., Chemosphere, Feb 2006
...alkaline and acid leaching between ash and SCWO residue. Table 1
Origin of the ashes Sample...Release of Fe, Al, PO4and Ca in ash A and SCWO
residue HCl NaOH M Fe% Al% PO4% Ca% M Fe...0.19 NaOH HCl M Fe% Al% PO4% M
Fe% PO4% SCWO 0 0.002 0.62 2.4 0 0.00 0.8 0.5 0.01 42...
6.
An
anti-corrosive reactor for the decomposition of halogenated hydrocarbons
with supercritical water oxidation Lee, H.C. / In, J.H. / Lee, S.Y. / Kim, J.H. / Lee, C.H., Jnl.
of Supercritical Fluids, Nov 2005
...porous ceramic tube (a) before, (b) after SCWO operation of
2,4-DCP and (c) shear strength...the general type and the floating type SCWO
reactors, and photographs of head, inside...residence time at
supercritical region in the SCWO of 2,4-DCP Pressure (bar) Maximum
temperature...
8.
Supercritical
water oxidation of o-dichlorobenzene: degradation studies and simulation
insights Svishchev, I.M. / Plugatyr, A., The Journal of Supercritical
Fluids, Feb 2006
...Abstract Supercritical water oxidation (SCWO) of an aromatic
chlorinated species,o-dichlorobenzene...temperature on the degradation
efficiency of the SCWO process. Experiments are also
performed...Introduction Supercritical water oxidation (SCWO) has
shown to be one of the most effective...
9.
Delocalized
organic pollutant destruction through a self-sustaining supercritical
water oxidation process Lavric, E.D. / Weyten, H. / De Ruyck, J. / Plesu, V. / Lavric, V., Energy
Conversion and Management, Jun 2005
...reaction schemes. Fig. 2 The flowsheet of SCWO process with a
supercritical steam turbine...scheme of closed Brayton cycle. Fig. 4 SCWO
flowsheet with closed Brayton cycle. Fig...Rankine cycle with
superheating. Fig. 6 SCWO flowsheet with organic Rankine cycle.
Table...
10.
Environmental
assessment of supercritical water oxidation and other sewage sludge
handling options. Magdalena Svanström / Morgan Fröling / Mattias Olofsson /
Margareta Lundin, Waste Manag Res, Aug 2005
...resource unit. Supercritical water oxidation (SCWO) can be used
for treatment of wet organic...has not yet been fully commercialized. SCWO
allows for complete oxidation of all organics...life-cycle assessment (LCA)
of sewage sludge SCWO (Aqua-Critox) is presented and the results...
11.
Critical
review of kinetic data for the oxidation of methanol in supercritical
water Vogel, F. / Blanchard, J.L.D. / Marrone, P.A. / Rice, S.F. / Webley,
P.A. / Peters, W.A. / Smith, K.A. / Tester, J.W., Jnl. of
Supercritical Fluids, Jul 2005
...al.[45]. Fig. 2 Schematic of a typical SCWO tubular flow reactor
set-up with separate...solid line). Fig. 6 Induction times for the SCWO
of methanol observed in tubular flow reactors...amperometric detector) of
reaction solutions from SCWO of methanol (upper trace), and from
methanol...
The
influence of Na2SO4 on the CO2 solubility
in water at high pressure Bermejo, M.D. / Martin, A. / Florusse, L.J. / Peters, C.J. / Cocero,
M.J., Fluid Phase Equilibria, Dec 2005
Supercritical water oxidation (SCWO) is a very efficient process for the
destruction of organic wastes. In this type of processes, conversions
higher than 99% can be achieved with residence times shorter than a
minute. The effluent of this...
The
destruction of industrial aqueous waste containing biocides in
supercritical water-development of the SUWOX process... Baur, S. / Schmidt, H. / Kramer, A. / Gerber, J., The Journal of
Supercritical Fluids, Feb 2005
...6. Fig. 3 Formation of acids during the SCWO process. Fig. 4
Formation of NaHCO 3 at...of s uper c ritical w ater o xidation (SCWO)
lies in the complete destruction of persistent...Chemie,
Chemisch-Physikalische Verfahren SCWO supercritical water oxidation
SUWOX supercritical...
16.
Probing
the chemical and electrochemical properties of SCWO systems Macdonald, D.D. / Kriksunov, L.B., Electrochimica Acta, Dec
2001
...chemical and electrochemical properties of SCWO systems Digby D.
Macdonald * * Corresponding...16802, USA Supercritical water oxidation (SCWO)
is currently being developed as a means...chemical agents. The advantages
offered by SCWO over incineration, for example, include...
17.
Cool
wall reactor for supercritical water oxidation - Modelling and operation
results Cocero, M.J. / Martinez, J.L., The Journal of Supercritical
Fluids, Sep 2004
...modelling of a supercritical water oxidation (SCWO) reactor
capable of operating effectively...Reactor design Supercritical water
oxidation (SCWO) Reactor modelling Reaction stable
intermediates...transversal surface (m 2 ) SS Stainless Steel SCWO
Supercritical water oxidation T Temperature...
18.
An
assessment of supercritical water oxidation (SCWO) - Existing problems,
possible solutions and new reactor concepts Kritzer, P. / Dinjus, E., Chemical Engineering Journal, Aug
2001
...assessment of supercritical water oxidation (SCWO) Existing
problems, possible solutions...process of supercritical water oxidation (SCWO)
is a promising alternative to the incineration...interest during the last
decade. However, SCWO as an end-of-pipe technology has some
disadvantages...
19.
Environmental
assessment of supercritical water oxidation of sewage sludge Svanstrom, M. / Froling, M. / Modell, M. / Peters, W.A. / Tester, J.,
Resources, Conservation and Recycling, Jul 2004
...of using supercritical water oxidation (SCWO) to treat sewage
sludge were studied using...system studied is the first commercial scale SCWO
plant for sewage sludge in the world, treating...production are also
important. Overall, SCWO processing of undigested sewage sludge...
20.
Destruction
of deca-chlorobiphenyl in supercritical water under oxidizing conditions
with and without Na2CO3 Fang, Z. / Xu, S.K. / Smith Jr., R.L. / Arai, K. / Kozinski, J.A., Jnl.
of Supercritical Fluids, Mar 2005
Decomposition of deca-chlorobiphenyl (10-CB) during pyrolysis and
oxidation in supercritical water (SCW) was studied in a hydrothermal
diamond anvil cell (HDAC) and batch reactors. HDAC was coupled with
optical and infrared microscopes....
21.
High
Curie temperature in B-site ordered Sr2CrWO6
epitaxial thin films Venimadhav, A. / Sher, F. / Attfield, J.P. / Blamire, M.G., Solid
State Communications, May 2006
...Fig. 1 (a)X-ray diffractiontheta-2thetascans of SCWO films (i)
on STO in Ar+O2, (ii) Ar alone, (iii...iii) shows the parasitic
phase.(b)phiscan of an SCWO film(c)(i)theta-2thetascans of SCWO
(111) peak on STO (ii)theta-2thetascans of SCWO...
22.
Supercritical
water oxidation of phenol and 2,4-dinitrophenol Vera Perez, I. / Rogak, S. / Branion, R., The Journal of
Supercritical Fluids, Jun 2004
...pilot-scale supercritical water oxidation (SCWO) system.
Treatment for approximately 40...conditions. Supercritical water oxidation
(SCWO) has been proposed as a technology capable...organic
hazardous wastes. The feasibility of SCWO as a waste destruction
technology has been...
23.
Salt
precipitation and scale control in supercritical water oxidation-part B:
commercial/full-scale applications Marrone, P.A. / Hodes, M. / Smith, K.A. / Tester, J.W., The
Journal of Supercritical Fluids, May 2004
...potential of supercritical water oxidation (SCWO) as a viable
technology for organic waste...expensive and frequent downtime of the SCWO
system. Other solids such as oxides exhibit...that have attempted to
commercialize the SCWO technology over the past two decades have...
24.
A
review of secondary sludge reduction technologies for the pulp and paper
industry Mahmood, T. / Elliott, A., Water Research, Jun 2006
...modified fromNichols, 1992). Fig. 7 Schematic of a sludge to oil
converter (modified fromCampbell, 1989). Fig. 8 Schematic of a SCWO
system (modified fromModell et al., 1992). Fig. 9 Schematic of a
wastewater treatment system with solubilization producing less...
25.
Salt
precipitation and scale control in supercritical water oxidation-Part A:
fundamentals and research Hodes, M. / Marrone, P.A. / Hong, G.T. / Smith, K.A. / Tester, J.W.,
The Journal of Supercritical Fluids, May 2004
...02139, USA Supercritical water oxidation (SCWO) is an effective
technology for treatment...of aqueous wastes. Commercialization of SCWO
processes has been hindered by concerns...operational procedures. Salts
are formed during SCWO when acidic solutions are neutralized to...
26.
Recent
advances on heat, chemical and process integration, multiobjective and
structural optimisation Klemes, J. / Stehlik, P., Applied Thermal Engineering, Sep
2006
...Integration (CREI) analysis[20]were applied to SCWO process and
the suitable network configuration...generation. Supercritical Water
Oxidation (SCWO) is the process of nearly complete
destruction...complete oxidation. Typical products from a SCWO
process include CO2, water, and inorganic...
27.
A
process for generating power from the oxidation of coal in supercritical
water Bermejo, M.D. / Cocero, M.J. / Fernandez-Polanco, F., Fuel,
Jan 2004
...oxidation of coal by supercritical water oxidation (SCWO) is
presented. Two versions of SCWO power plant are compared to two of
the most efficient...state. Calculated results show that net work in SCWO
power plant is 5% higher than in other power plants...
28.
Stainless
steel flow reactor for supercritical water oxidation: corrosion tests Hayward, T.M. / Svishchev, I.M. / Makhija, R.C., The Journal of
Supercritical Fluids, Dec 2003
...development of supercritical water oxidation (SCWO) into a
viable industrial process, is the...contributing factor to the corrosion
of SCWO experiment. Supercritical water oxidation...recent years
supercritical water oxidation (SCWO) has emerged as a promising new
technology...
Recycling
of sludge with the Aqua Reci process. K Stendahl / S Jäfverström, Water Sci Technol, Feb
2004
Supercritical Water Oxidation (SCWO) is an innovative and effective
destruction method for organics in sewage sludge. The SCWO process
leaves a slurry of inorganic ash...Reci. In a continuous pilot plant for
the SCWO process digested sludge has been treated...
31.
Spatial
hydration structures and dynamics of phenol in sub- and supercritical
water Andriy Plugatyr / Istok Nahtigal / Igor M. Svishchev, The
Journal of Chemical Physics, Jan 2006
...Diffusion and thermal diffusion in liquids Body INTRODUCTION The
continual development of the supercritical water oxidation (SCWO)
technology and other innovative applications of high-temperature water (in
advanced power cycles, hydrometallurgy, etc.) have...
05/02794
Developmental and environmental effects of the Kizildere geothermal power
project, Turkey Fuel and Energy Abstracts, Nov 2005
...1345-1364. Supercritical water oxidation (SCWO) is a recent
development aiming at the...paper focuses on the process simulation of SCWO
with emphasis on the proper modelling of...conditions and on the
possibility to make the SCWO process self-sufficient from the
energetic...
35.
05/02797
Hazard assessment of substances produced from the accidental heating of
chemical compounds Fuel and Energy Abstracts, Nov 2005
...1345-1364. Supercritical water oxidation (SCWO) is a recent
development aiming at the...paper focuses on the process simulation of SCWO
with emphasis on the proper modelling of...conditions and on the
possibility to make the SCWO process self-sufficient from the
energetic...
36.
In
situ characterisation of the oxidation of Ni in ultrasupercritical water Betova, I. / Bojinov, M. / Kinnunen, P. / Lehtovuori, V. / Peltonen, S.
/ Penttila, S. / Saario, T., Electrochemistry Communications,
Feb 2006
...The major disadvantages of SCW oxidation (SCWO) revolve around
high pressure (P 23MPa...waste streams, corrosion[5-7]. Although SCWO
is technologically able to destroy hazardous...not be suitable for the
most aggressive SCWO feed streams because they can exhibit both...
37.
Catalytic
denitrogenation of hydrocarbons through partial oxidation in supercritical
water Yuan, P.Q. / Cheng, Z.M. / Zhang, X.Y. / Yuan, W.K., Fuel,
Feb 2006
...hydrocarbons through catalytic SCW oxidation (SCWO), trying to
provide some fundamental information...pyrolysis as well as direct
oxidation under SCWO environment. In order to evaluate the
contribution...oxidation to the denitrogenation under SCWO
environment was hereby neglected. For the...
38.
Radiolysis
of phenol in aqueous solution at elevated temperatures Miyazaki, T. / Katsumura, Y. / Lin, M. / Muroya, Y. / Kudo, H. /
Taguchi, M. / Asano, M. / Yoshida, M., Radiation Physics and
Chemistry, Mar 2006
...dibenzofuran, and dibenzo-p-dioxin in the SCWO of phenol. They
reported this may be due...radiolysis of phenol in aqueous solution and SCWO.
However, in gas-phase reaction between...studied by this work and
literature in SCWO, gas-phase reaction and pulse radiolysis...
39.
05/02796
Estimate of ecological efficiency for thermal power plants in Brazil Fuel and Energy Abstracts, Nov 2005
...1345-1364. Supercritical water oxidation (SCWO) is a recent
development aiming at the...paper focuses on the process simulation of SCWO
with emphasis on the proper modelling of...conditions and on the
possibility to make the SCWO process self-sufficient from the
energetic...
OPA
oxidation rates in supercritical water Veriansyah, B. / Kim, J.D. / Lee, J.C. / Lee, Y.W., Journal of
Hazardous Materials, Sep 2005
...oxidation experiments conducted in the SCWO flow reactor
Reaction temperature (K) Residence...investigated under supercritical
water oxidation (SCWO) conditions in an isothermal tubular
reactor...Studies of supercritical water oxidation (SCWO) for
treating and destroying CWAs are underway...
44.
Advanced
vehicle routing algorithms for complex operations management problems Tarantilis, C.D. / Ioannou, G. / Prastacos, G., Journal of Food
Engineering, Oct 2005
Vehicle routing encompasses a whole class of complex optimization problems
that target the derivation of minimum total cost routes for a number of
resources (vehicles) located at a central point (depot) in order to
service efficiently a...
45.
Supercritical
water oxidation of sulfide. Tao Wang / Botao Xiang / Jun Liu / Zhongyao Shen, Environ Sci
Technol, May 2003
Supercritical water oxidation (SCWO) of sulfide wastewater with
oxygen as the...were conducted in a bench-scale continuous SCWO
installation, indicated that S2- could...MPa-30.0 MPa. The reaction
pathway of S2- in SCWO was determined to be S2- -- S2O3(2...
46.
Flameless
incineration of pyrene under sub-critical and supercritical water
conditions Onwudili, J.A. / Williams, P.T., Fuel, Jan 2006
...5]. Many supercritical water oxidation (SCWO) experiments have
been conducted at temperatures...needed for suitable application of the SCWO
process. Excellent destruction efficiencies...these reports confirm the
effectiveness of SCWO in the decomposition of organic pollutants...
47.
Project
M3-a study for a manned Mars mission in 2031 Taraba, M. / Zwintz, K. / Bombardelli, C. / Lasue, J. / Rogler, P. /
Ruelle, V. / Schlutz, J. / (...) / Sinzig, B., Acta Astronautica,
Jan 2006
This study deals with a manned mission which focuses on building an
orbital station around Mars. The advantages in comparison to
direct-landing scenarios are outlined and the necessary technology is
described. The orbiting station prohibits...
48.
Subject
Index Fluid Phase Equilibria, Dec 2005
...239 Prediction, 52 Predictive equation of state, 157 Propane, 13
Protein system, 52 PSRK, 1 Pure, 58 Pyridine, 87 SAFT, 254 SCWO,
220 Second cross virial coefficients, 229 Silybin, 186 Sodium sulphate,
220 Solubility of electrolytes, 180 Solubility, 7, 26.
49.
Supercritical
water oxidation of the PCB congener 2-chlorobiphenyl in methanol
solutions: a kinetic analysis. Christopher P O'Brien / Mark C Thies / David A Bruce, Environ
Sci Technol, Sep 2005
...forms. This study examined the supercritical water oxidation (SCWO)
of 2-chlorobiphenyl (2-PCB), using hydrogen peroxide as the...33.2 kJ/mol.
The primary organic reaction products from the SCWO of 2-PCB were
biphenyl at low temperatures (
50.
OPA
oxidation rates in supercritical water. Bambang Veriansyah / Jae-Duck Kim / Jong-Chol Lee / Youn-Woo Lee, J
Hazard Mater, Sep 2005
...OPA), one of high-risk wastes resulting from munitions
demilitarization, was investigated under supercritical water oxidation (SCWO)
conditions in an isothermal tubular reactor. H2O2 was used as the oxidant.
The reaction temperatures were ranged from 684 to...
51.
Catalytic
desulfurization of residual oil through partial oxidation in supercritical
water Yuan, P.Q. / Cheng, Z.M. / Jiang, W.L. / Zhang, R. / Yuan, W.K., Jnl.
of Supercritical Fluids, Aug 2005
...reduction mechanism of VR through catalytic SCWO. Catalytic
desulfurization of residual...were carried out under an SCW oxidation (SCWO)
environment in the presence of CoMo/gamma-Al2O3catalyst...desulfurization,
the stability of catalyst in an SCWO environment was examined. It
was found...
52.
Kinetic
model of wet oxidation of phenol at basic pH using a copper catalyst Santos, A. / Yustos, P. / Quintanilla, A. / Garcia-Ochoa, F., Chemical
Engineering Science, Sep 2005
...oxidation (WAO), supercritical water oxidation (SCWO) and
incineration. AOPs are commonly used...1997 Andreozzi et al., 1999). WAO
and SCWO are attractive alternatives to treat an...5-200bar for WAO
and above374?Cand 221bar for SCWO), WAO seems to be more accepted
than SCWO...
53.
Reaction
mechanism of styrene monomer recovery from waste polystyrene by
supercritical solvents Ke, H. / Li-hua, T. / Zi-bin, Z. / Cheng-fang, Z., Polymer
Degradation and Stability, Aug 2005
...results[11,12]. Supercritical water oxidation (SCWO) is a
rapidly emerging-waste-treatment method that...14]obtained high yield of
styrene monomer using SCWO to pyrolyse polystyrene. Though SCWO
has many advantages in cracking polymeric materials...
54.
Phosphate
recovery from sewage sludge in combination with supercritical water
oxidation. K Stendahl / S Jäfverström, Water Sci Technol, Feb
2003
Supercritical Water Oxidation (SCWO) is an innovative and effective
destruction method for organics in sewage sludge. The SCWO process
leaves a slurry of inorganic ash...sludge. In a continuous pilot plant for
the SCWO process digested sludge has been treated...
55.
Co-oxidation
effects of methanol and benzene on the decomposition of 4-chlorobiphenyl
in supercritical water Anitescu, G. / Munteanu, V. / Tavlarides, L.L., The Journal of
Supercritical Fluids, Feb 2005
...A comparison of 4CB reaction products (SCWO) shown by two GC-MSD
chromatograms in presence...RPs). Table 3 Reaction products of 4CB SCWO
at 773 K, 25 MPa, and 24.5 s residence...Introduction Supercritical water
oxidation (SCWO) is a process developed in particular to...
56.
Supercritical
water oxidation process under energetically self-sufficient operation Cocero, M.J. / Alonso, E. / Sanz, M.T. / Fdz-Polanco, F., The
Journal of Supercritical Fluids, Sep 2002
...study of the supercritical water oxidation (SCWO) process for
diluted wastewater is presented...Introduction Supercritical water
oxidation (SCWO) has demonstrated to be a powerful
technology...determination of reaction heats in the SCWO process.
Chen et al. [4] propose an oxidation...
57.
New
approach for kinetic parameters determination for hydrothermal oxidation
reaction Mateos, D. / Portela, J.R. / Mercadier, J. / Marias, F. / Marraud, C. /
Cansell, F., Jnl. of Supercritical Fluids, May 2005
...of water, the process is called supercritical water oxidation (SCWO)
and it typically implies pressures and temperatures varying...kinetic
studies on phenol, that the parameters obtained in WAO and SCWO
could not be used in operating conditions different from those...
58.
Dynamical
and structural properties of benzene in supercritical water Carlos Nieto-Draghi / Josep Bonet Àvalos / Oliver Contreras /
Philippe Ungerer / Jacqueline Ridard, The Journal of Chemical
Physics, Nov 2004
...temperature conditions are of particular interest. Examples are
supercritical water oxidation (SCWO) and supercritical extraction,
among others. For instance, SCWO becomes an important application
because it provides a reliable way to destroy biochemical...
59.
Wet
peroxide oxidation of chlorophenols Garcia-Molina, V. / Lopez-Arias, M. / Florczyk, M. / Chamarro, E. /
Esplugas, S., Water Research, Mar 2005
...technologies Supercritical Water Oxidation (SCWO), Subcritical
Oxidation or Wet Oxidation...operating costs (Catrinescu et al., 2003). SCWO
takes place above the critical point of...as oxidizing agent is common to
WO and SCWO processes. There is also one more process...
60.
Evaluation
of biomass gasification in supercritical water process for hydrogen
production Calzavara, Y. / Joussot-Dubien, C. / Boissonnet, G. / Sarrade, S., Energy
Conversion and Management, Mar 2005
Converting biomass into hydrogen can be accomplished in supercritical
water. State of the art experiments are thoroughly presented. Chars and
tars formation may be the most significant technological problem. However,
catalysis should be...
61.
Temperature
and pressure dependence of the absorption spectra and decay kinetics of
solvated electrons in ethanol from... Han, Z. / Katsumura, Y. / Lin, M. / He, H. / Muroya, Y. / Kudo, H.,
Chemical Physics Letters, Mar 2005
...destruction of the hazardous chemical waste has been proposed recently
by employing supercritical water oxidization process (SCWO). On the
other hand, comparing to water, the primary alcohols have much milder
critical points, for example, for water and ethanol...
62.
Isochoric
heat capacity measurements for a CO2 + n-decane mixture in the
near-critical and supercritical regions Polikhronidi, N.G. / Batyrova, R.G. / Abdulagatov, I.M. / Magee, J.W. /
Stepanov, G.V., Jnl. of Supercritical Fluids, Mar 2005
...number of technological applications including coal conversion, organic
synthesis, destructive oxidation of hazardous wastes (SCWO
processes), enhanced oil recovery, activated carbon regeneration,
formation of inorganic films and powders, supercritical chromatography...
63.
Pressurized
hot water extraction coupled with supercritical water oxidation in
remediation of sand and soil containing... Kronholm, J. / Kalpala, J. / Hartonen, K. / Riekkola, M.-L., The
Journal of Supercritical Fluids, Jun 2002
...PHWE) and supercritical water oxidation (SCWO) equipment was
constructed to extract polyaromatic...performed safely and effectively,
and the PHWE-SCWO procedure gave good extraction
recoveries...extraction (PHWE) Supercritical water oxidation (SCWO)
Soxhlet extraction Waste treatment 1 Introduction...
64.
Hydrothermal
reactions of methylamine Benjamin, K.M. / Savage, P.E., The Journal of Supercritical
Fluids, Nov 2004
...typical of supercritical water oxidation (SCWO) reactors, the
reaction seems to be governed...systems is supercritical water oxidation (SCWO).
This waste treatment technology uses...oxidizing harmful organic compounds
[3] . SCWO exploits the unique solvating properties...
65.
Supercritical
waste hydrothermal treatment modelisation of non-stationary phenomena in a
reactor Dutournie, P. / Mercadier, J., The Journal of Supercritical
Fluids, Dec 2004
...temperature. Super critical water oxidation (SCWO, P = 22.1 MPa
and 374 = 99.99%) in relatively...1994 and treats chemical wastewater by SCWO.
This unit treats 1 m 3 h -1 of liquid...simulation tools is necessary for
scaling up SCWO process. Some authors [2-4] use trading...
66.
Real
options and the value of generation capacity in the German electricity
market Hlouskova, J. / Kossmeier, S. / Obersteiner, M. / Schnabl, A., Review
of Financial Economics, Jan 2005
...Vehicle MSL Mars Science Laboratory MSO Mars Science Observatory NTP
Nuclear Thermal Propulsion PE polyethylene S/C spacecraft SCWO
Super Critical Wet Oxidation SEM Surface Excursion Module SOHO Solar and
Heliospheric Observatory SOI sphere of influence SPE...
Oxidation
of 4-chloro-3-methylphenol in pressurized hot water in liquid and vapor
phases Kronholm, J. / Huhtala, S. / Haario, H. / Riekkola, M.-L., Advances
in Environmental Research, Sep 2002
4-Chloro-3-methylphenol (c=2.0 mM), representing a model pollutant, was
oxidized both in liquid and vapor phases. The oxidant (hydrogen peroxide)
was used in an amount equivalent to 10 times that of the model pollutant.
Space times were...
69.
Reactions
of vanillic acid in sub- and supercritical water Gonzalez, G. / Salvado, J. / Montane, D., The Journal of
Supercritical Fluids, Sep 2004
The hydrothermal reactions of vanillic acid in water near the critical
point have been investigated in a continuous tubular reactor at
temperatures between 280 and 500^oC and pressures between 225 and 300bar.
Formation of...
70.
Hot
compressed water—a suitable and sustainable solvent and reaction medium? E Dinjus / A Kruse, Journal of Physics: Condensed Matter,
Apr 2004
...In supercritical water oxidation (SCWO) water is used as a
medium in which organic...known as supercritical water oxidation (SCWO),
has been worked out since the 1980s...from [2]). see [3–10, 36]). During
the SCWO process, the organic compounds react completely...
71.
Sulfur
transformations during supercritical water oxidation of a Chinese coal Wang, T. / Zhu, X., Fuel, Dec 2003
...semi-continuous Supercritical Water Oxidation (SCWO)
installation, indicated that the sulfur...containing sulfur in the
effluents of coal SCWO were determined as sulfide, thiosulfate...time
on the sulfur transformations during SCWO of coal were also
investigated. Coal Supercritical...
72.
Generalized
kinetic models for supercritical water oxidation of cutting oil wastes Portela, J.R. / Nebot, E. / Martnez de la Ossa, E., The Journal
of Supercritical Fluids, Oct 2001
...Spain Supercritical Water Oxidation (SCWO) has been proved to be
a powerful technology...the literature about the application of SCWO
to oily wastes. Even though these industrial...found in the literature. In
this work, SCWO have been tested to treat cutting oil wastes...
73.
Raman
spectroscopic study of CO2-NaCl-H2O mixtures in
synthetic fluid inclusions at high temperatures Chen, J. / Zheng, H. / Xiao, W. / Zeng, Y. / Weng, K., Geochimica
et Cosmochimica Acta, Mar 2004
Mixtures of CO"2-NaCl-H"2O contained in synthetic fluid
inclusions are studied by laser Raman spectroscopy at high temperatures.
With increasing temperature, the band splitting (X) of
@u"1-2@u"2 diad of spectrum of CO"2 presents more...
74.
Corrosion
in high-temperature and supercritical water and aqueous solutions: a
review Kritzer, P., The Journal of Supercritical Fluids, Apr 2004
...is given and compared with an oxidative treatment in air at the same
temperatures, but ambient pressure. Taking into account SCWO-typical
oxygen concentrations of around 5 mol/kg and a reaction pressure of 25 MPa,
this results in an oxygen partial pressure...
75.
A
double-wall reactor for hydrothermal oxidation with supercritical water
flow across the inner porous tube Fauvel, E. / Joussot-Dubien, C. / Guichardon, P. / Charbit, G. /
Charbit, F. / Sarrade, S., The Journal of Supercritical Fluids,
Jan 2004
...Supercritical water oxidation process (SCWO), which involves the
destruction of organic...dispose of those dangerous wastes. The SCWO
advantages are linked to the special physical...precipitation are the two
main limitations of SCWO process. They have to be overcome in
order...
76.
Catalytic
supercritical water oxidation of wastewater from terephthalic acid
manufacturing process Park, T.-J. / Lim, J.S. / Lee, Y.-W. / Kim, S.-H., The Journal
of Supercritical Fluids, Aug 2003
...Therefore, supercritical water oxidation (SCWO) is known to be
one of the most promising...compounds including PCBs and dioxins.
Nowadays, SCWO is being applied in pilot plants and a...of a
heterogeneous catalyst can improve SCWO for the complete conversion
of aromatic...
77.
Electrochemical
study of corrosion in aqueous high pressure, high temperature media and
measurements of materials... Delville, M.H. / Botella, P. / Jaszay, T. / Frayret, J.P., The
Journal of Supercritical Fluids, Jun 2003
...applications to the hydrothermal treatments of organic wastes by SCWO
M.H. Delville a * * Corresponding author. Tel.: +33-5-5684-8460...are
particularly dangerous and rapidly corrode the reactor of SCWO
pilots. We, therefore, undertook a study of different aqueous...
78.
Kinetic
comparison between subcritical and supercritical water oxidation of phenol Portela, J.R. / Nebot, E. / Martnez de la Ossa, E., Chemical
Engineering Journal, Jan 2001
...WAO) and supercritical water oxidation (SCWO) processes have
been studied by numerous...referred to as super critical water oxidation (SCWO),
is carried out at pressures and temperatures...for a given organic, i.e.
phenol [7] . SCWO is a promising emerging technology, not...
79.
Magnetic
inhomogeneity and valence state in SrCrWO double perovskite Jinhui Wang / Gongqiang Liu / Wei Zhong / Youwei Du, Journal of
Applied Physics, Dec 2002
...this article, the (designated herein as SCWO) ceramics without
ferrous ion have been...per formula unit for completely ordered SCWO,
only half of that of In this article...properties as well as XPS and FMR
spectra for SCWO. II. EXPERIMENT The SCWO ceramics were...
80.
Editorial Johnstone, H., Filtration and Separation, Jun 2003
...precious metals from spent catalysts is now available. We find out more
about the AquaCat (R) supercritical water oxidation (SCWO) process
on p.16-19. Continuing the product recovery theme we switch to the highly
competitive brewing industry, where market...
81.
Experimental
study, via current-potential curves, of the anodic behavior of Alloy C-276
and T60 titanium in chlorinated... Botella, P. / Frayret, C. / Jaszay, T. / Delville, M.H., The
Journal of Supercritical Fluids, Apr 2003
...build-up for supercritical water oxidation (SCWO) of organic
wastes. These preliminary results...to the oxidative context of the media
in SCWO processes. The determination of the corrosion...intrinsic
resistance to corrosion phenomena in SCWO conditions. One of the
main reasons of...
82.
Recovery
of Precious Metal Catalysts with Supercritical Water Oxidation Filtration and Separation, Jun 2003
...catalysts. ). The process utilizes supercritical water oxidation (SCWO)
a technique previously patented by Chematur Engineering. When...Johnson
Matthey and Chematur are now be able to provide an on-site SCWO
plant, so that these hazardous materials can be treated at the...
83.
Destruction
of PAHs from soil by using pressurized hot water extraction coupled with
supercritical water oxidation Kronholm, J. / Kuosmanen, T. / Hartonen, K. / Riekkola, M.-L., Waste
Management, Jan 2003
...PHWE) and supercritical water oxidation (SCWO) are advanced
techniques relying on water...effectively destructed in wastewater by SCWO:
municipal and industrial wastewaters containing...oxygen are the most
common oxidants used in SCWO, and the normal operating
temperatures...
84.
Platinum
catalysed wet oxidation of phenol in a stirred slurry reactor - The role
of oxygen and phenol loads on... Masende, Z.P.G. / Kuster, B.F.M. / Ptasinski, K.J. / Janssen, F.J.J.G.
/ Katima, J.H.Y. / Schouten, J.C., Catalysis Today, Apr 2003
...phenol first followed by phenol Pt platinum SCWO supercritical
water oxidation S.E. stoichiometric...identified during supercritical
water oxidation (SCWO) of phenol [10] . Phenol reaction networks in
SCWO have been recently reviewed [10] , in which...
85.
Platinum
catalysed wet oxidation of phenol in a stirred slurry reactor - A
practical operation window Masende, Z.P.G. / Kuster, B.F.M. / Ptasinski, K.J. / Janssen, F.J.J.G.
/ Katima, J.H.Y. / Schouten, J.C., Applied Catalysis B:
Environmental, Mar 2003
...selectivity to compound i (%) Sc Schmidt number SCWO
supercritical water oxidation S.E. stoichiometric...etc. [5] .
Supercritical water oxidation (SCWO) processes are carried out at
supercritical conditions. A recent review [6] on SCWO processes
shows that complete and rapid...
86.
Uncertainty
quantification in reacting-flow simulations through non-intrusive spectral
projection Reagana, M.T. / Najm, H.N. / Ghanem, R.G. / Knio, O.M., Combustion
and Flame, Feb 2003
...focus on supercritical water oxidation (SCWO). Supercritical
water oxidation has been...rapidly and completely. The design of the SCWO
process requires the development of appropriate...hydrogen-oxygen
freely-propagating flame at SCWO conditions, computed with the
Chemkin PREMIX...
87.
Muonium
kinetics in sub- and supercritical water Ghandi, K. / Addison-Jones, B. / Brodovitch, J.C. / Kecman, S. /
McKenzie, I. / Percival, P.W., Physica B, Feb 2003
...destruction by supercritical water oxidation (SCWO) [1-3] and
NCW or SCW for cooling and power...for the design and optimization of
future SCWO reactors [2,3] as well as the next generation...to
provide experimental data relevant to SCWO processes and the
radiolysis of water in...
88.
A
computational model for supercritical water oxidation of organic toxic
wastes Zhou, N. / Krishnan, A. / Vogel, F. / Peters, W.A., Advances in
Environmental Research, Jun 2000
...simulate the supercritical water oxidation (SCWO) process for
organic wastes. The SUPERTRAPP...reactor geometry was performed for
methane SCWO in a co-axial reactor and the optimized...heat and
chemistry simulations of methanol SCWO in the CSTR at MIT Energy
Lab were also...
89.
Hydrogen
generation from ethanol in supercritical water without catalyst Arita, T. / Nakahara, K. / Nagami, K. / Kajimoto, O., Tetrahedron
Letters, Jan 2003
...interest has been focused on the supercritical water oxidation (SCWO)
to decompose hazardous chemicals such as PCB, dioxins and
chlorinated...should be further oxidized to acetic acid as was observed in
SCWO. 15 Thus, the absence of acetic acid production in the
present...
90.
H4SiW12O40-catalyzed
oxidation of nitrobenzene in supercritical water: kinetic and mechanistic
aspects Arslan-Alaton, I. / Ferry, J.L., Applied Catalysis B:
Environmental, Oct 2002
...Introduction Supercritical water oxidation (SCWO) has been
gaining importance as a feasible...hazardous waste. After extended
exposure to the SCWO process, organic compounds are
oxidized...requirements are the major goals of catalytic SCWO and
several articles describing heterogeneously...
91.
Catalytic
wet oxidation of phenol in a trickle bed reactor over a Pt/TiO2
catalyst Maugans, C.B. / Akgerman, A., Water Research, Jan 2003
...including wet air oxidation (WAO), and supercritical water oxidation (SCWO).
WAO involves treating the aqueous organics with air at elevated
temperature and pressures [3-12] and SCWO is the same, but
occurring above the critical point of water [13-20...
92.
Potentiometric
pH measurements in acidic sulfate solutions at 250 oC relevant
to pressure leaching Seneviratne, D.S. / Papangelakis, V.G. / Zhou, X.Y. / Lvov, S.N., Hydrometallurgy,
Feb 2003
A flow-through yttria-stabilized zirconia (FTYSZ) electrode has been
employed for pH measurements at 250 ^oC in concentrated electrolyte
systems relevant to hydrometallurgical processing of nickeliferous
laterites. Experiments were...
93.
Life
support approaches for Mars missions Drysdale, A.E. / Ewert, M.K. / Hanford, A.J., Advances in Space
Research, Jan 2003
...elsewhere. This oxidation can be done in a variety of ways, from PC
systems such as incineration and super critical wet oxidation (SCWO)
to biological systems such as composting. A high degree of food closure
does have the advantage that there is very little waste...
94.
Recycling
efficiencies of C,H,O,N,S, and P elements in a biological life support
system based on micro-organisms and... Gros, J.B. / Poughon, L. / Lasseur, C. / Tikhomirov, A.A., Advances
in Space Research, Jan 2003
...dioxide required for the plant growth. Two ways can be considered. The
first consists of a physico-chemical process (wet oxidation, SCWO,
combustion/incineration) (Eckart, 1994), the second consists of taking
advantage of the possible ability of the liquefying compartment...
95.
Modeling
of supercritical water oxidation of phenol catalyzed by activated carbon Nunoura, T. / Lee, G.H. / Matsumura, Y. / Yamamoto, K., Chemical
Engineering Science, Aug 2002
...oxygen. Thus, supercritical water oxidation (SCWO) is an
efficient technology for the ultimate...the problems for the application
of the SCWO. For the purpose of mitigating the
severity...application of a suitable catalyst to the SCWO at a
lower operating temperature is efficient...
96.
Hydrothermal
flames in supercritical water oxidation: investigation in a pilot scale
continuous reactor Serikawa, R.M. / Usui, T. / Nishimura, T. / Sato, H. / Hamada, S. /
Sekino, H., Fuel, Jun 2002
...Introduction Supercritical water oxidation (SCWO) has been
considered an alternative to...several wastes. The public image for SCWO
is still a non-flame disposal and an extension process of wet oxidation. SCWO
proceeds by bringing together an oxidant...
97.
Minimization
of cobalt nuclide emissions in supercritical water oxidation of spent
resin Huang, Y.-J. / Paul Wang, H. / Li, C.-T. / Chien, Y.-C., Chemosphere,
Feb 2000
...organics in the supercritical water oxidation (SCWO) of the
Co-exchanged resin was found experimentally...formed and separated
effectively in the SCWO process, a minimal release of the
nuclide...species at elevated temperatures ( 1040 K). SCWO
Low-level radioactive wastes Nuclide emission...
98.
Minimization
of cobalt nuclide emissions in supercritical water oxidation of spent
resin. Y J Huang / H P Wang / C T Li / Y C Chien, Chemosphere, Feb
2000
...destruction of organics in the supercritical water oxidation (SCWO)
of the Co-exchanged resin was found experimentally. Due to an...solubility
of CoSO4 salt formed and separated effectively in the SCWO process,
a minimal release of the nuclide Co would be warranted...
99.
Pressurised
hot water extraction and thermal desorption of polycyclic aromatic
hydrocarbons from sediment with use of a... Andersson, T. / Hartonen, K. / Hyotylainen, T. / Riekkola, M.-L., Analytica
Chimica Acta, Aug 2002
...directly to LC or LC-GC [13] . Finally, it is worth to mention, that
PHWE can be online coupled with supercritical water oxidation (SCWO),
which enables successive extraction and oxidation of PAHs from soil [14] .
PAHs are formed by incomplete combustion of fossil...
100.
Research
trends Membrane Technology, Apr 2002
...wastewater Supercritical Water Oxidation (SCWO) was proposed
almost 20 years ago as a...substances such as carbon dioxide and water. SCWO
usually operates at a pressure of about...with other waste purification
processes, SCWO is characterized by high investment and...
101.
Shape
selectivity of trace by-products for supercritical water oxidation of
2-chlorophenol effected by CuO/ZSM-48 Lin, K.-S. / Wang, H.P., Applied Catalysis B: Environmental,
Oct 1999
...by-products in supercritical water oxidation (SCWO) of
2-chlorophenol (2CP) catalyzed by CuO...Experimentally, destruction
efficiency of 2CP in the SCWO process is effectively enhanced by
CuO...Cl-reinsertion) is extremely suppressed in the SCWO of 2CP
compared to those observed for zeolites...
102.
Elimination
of cutting oil wastes by promoted hydrothermal oxidation Portela, J.R. / Lopez, J. / Nebot, E. / Martnez de la Ossa, E., Journal
of Hazardous Materials, Nov 2001
...WAO) and supercritical water oxidation (SCWO) are two forms of
hydrothermal oxidation...due to the moderate temperatures used. SCWO
is a more powerful process since operating...technology. In order to
enhance WAO and SCWO efficiency at mild conditions, the use...
103.
Supercritical
water oxidation of 2-chlorophenol effected by Li+ and CuO/Zeolites Lin, K.-S. / Wang, H.P. / Yang, Y.W., Chemosphere, Oct 1999
...conversion of ZCP in superchtical wmer oxidabon (SCWO) process
is eictive]y enhmced n the presence...phenols and PAHs. The global reachon
mte of SCWO of 2CP hz the presence of LX is expressed...O]0 45. The
undesired by-pmducts in the SCWO of ZCP are also extensive]y
reduced ~a...
104.
Decomposition
of aniline in supercritical water Qi, X.-H. / Zhuang, Y.-Y. / Yuan, Y.-C. / Gu, W.-X., Journal of
Hazardous Materials, Feb 2002
...the oxidation behavior of aniline with supercritical water oxidation (SCWO)
process was studied. SCWO technology is a novel waste treatment
process developed since 1980. The SCWO process takes advantage of
the fact that above the critical point of...
105.
Elimination
of cutting oil wastes by promoted hydrothermal oxidation. J R Portela / J López / E Nebot / E Martínez de la Ossa, J
Hazard Mater, Nov 2001
...WAO) and supercritical water oxidation (SCWO) are two forms of
hydrothermal oxidation...due to the moderate temperatures used. SCWO
is a more powerful process since operating...technology.In order to
enhance WAO and SCWO efficiency at mild conditions, the use...
106.
Environment Focus on Catalysts, Feb 2002
...conversion rate. European Chemical News, 17 Dec 2001, 75 (1986), 26 SCWO
process for platinum group metals recovery A facility for the...mid-2002,
and the Aqua Critox supercritical water oxidation (SCWO) process
will be used to recover the metals. The technology has...
Organic
sulfur and hap removal from coal using hydrothermal treatment Timpe, R.C. / Mann, M.D. / Pavlish, J.H. / Louie, P.K.K., Fuel
Processing Technology, Oct 2001
...study of the economics of supercritical water oxidation (SCWO)
for use in waste treatment has been done. The hardware...hydrothermal
treatment are quite similar to that of SCWO, although in SCWO,
operating conditions are substantially more severe...
109.
Catalytic
decarboxylation of acetic acid with zirconia catalyst in supercritical
water Watanabe, M. / Inomata, H. / Smith, R.L. / Arai, K., Applied
Catalysis A: General, Oct 2001
...intermediate of supercritical water oxidation (SCWO) process
[10] , can be a probe for testing...destruction of acetic acid is low even
in SCWO condition [10] , the rate of decomposition...development of
a more rapid and lower energy cost SCWO process. Belsky et al. [11]
conducted the...
110.
Global
reaction heat of acetic acid oxidation in supercritical water Aymonier, C. / Gratias, A. / Mercadier, J. / Cansell, F., The
Journal of Supercritical Fluids, Nov 2001
...oxidation: research Chem. Oxid. 5 1995 1 [4] Schmieder H. Abeln J. SCWO:
facts and hopes Wiss. Ber.-Forschungszent. Karlsruhe 6271 1999...materials
during the process of Supercritical Water Oxidation (SCWO) The 6th
Meeting on Supercritical Fluids: Chemistry and Materials...
111.
Catalyst
activity, stability, and transformations during oxidation in supercritical
water Yu, J. / Savage, P.E., Applied Catalysis B: Environmental,
May 2001
...exposure to supercritical water oxidation (SCWO) conditions,
whereas the supported CuO...treated by supercritical water oxidation (SCWO).
This technology [1-3] converts organic...critical point of water (374 C,
218 atm). SCWO is effective for a wide variety of potential...
112.
Partial
oxidation of propane in sub- and supercritical water Armbruster, U. / Martin, A. / Krepel, A., The Journal of
Supercritical Fluids, Nov 2001
...interest during the last 20 years especially as a reaction medium for
the total oxidation of wastes (supercritical water oxidation, SCWO
[1] ). Meanwhile, this technology has been developed to commercial scale.
The process usually is carried out at temperatures...
113.
Phenol
oxidation over CuO/Al2O3 in supercritical water Yu, J. / Savage, P.E., Applied Catalysis B: Environmental,
Dec 2000
...non-catalytic supercritical water oxidation (SCWO). It also
simultaneously reduced the yield...rate law used previously for catalytic SCWO
of phenol over other transition metal oxides...technology termed
supercritical water oxidation (SCWO). Conventional SCWO
processes, which usually...
114.
Oxidation
of printed circuit board wastes in supercritical water Chien, Y.-C. / Wang, H.P. / Lin, K.-S. / Yang, Y.W., Water
Research, Dec 2000
...enhanced in the supercritical water oxidation (SCWO) process. By
X-ray diffraction (XRD) spectroscopy...bromine species from the resin
matrix in the SCWO process. supercritical water printed
circuit...Ca 2+ or K + in the early stage of the SCWO of
2-chlorophenol was observed ( Lin et...
115.
Hydrolysis
and oxidative decomposition of ethyl acetate in sub- and super-critical
water Armbruster, U. / Martin, A. / Krepel, A., Applied Catalysis B:
Environmental, Jun 2001
...dealing with the treatment of contaminated aqueous effluents under
super-critical conditions (super-critical water oxidation, SCWO) to
realise these advantages for disposal of hazardous compounds, e.g. [3] .
Results were promising, but this technology still...
116.
Heterogeneous
catalysis in supercritical water Savage, P.E., Catalysis Today, Nov 2000
...goal of supercritical water oxidation (SCWO). This technology
provides an alternative...severity of the processing conditions of SCWO
and thereby improve the economics has motivated...thorough review of work
related to catalytic SCWO, published by early 1996.
Heterogeneous...
117.
Advances
with supercritical fluids [review] Hauthal, W.H., Chemosphere, Apr 2001
...Peng-Robinson-Stryjek-Vera e.o.s RK e.o.s. Redlich-Kwong equation of
state SAFT statistical associating fluid theory sc supercritical SCWO
supercritical water oxidation SFC supercritical fluid chromatography SFE
supercritical fluid extraction SPE solid-phase extraction...
118.
Measurement
of the high-pressure-high-temperature fluid phase behavior of the systems
CF4+H2O, CF4+H2O+NaCl,... Smits, P.J. / Peters, C.J. / de Swaan Arons, J., Fluid Phase
Equilibria, Sep 1998
...high-pressure-high-temperature fluid phase behavior of model systems
encountered in supercritical water oxidation processes (SCWO) for
the destruction of CFCs has been detertnined experimentally. For that
purpose, the following systems have been selected...
119.
Selected
Titles Polymer Contents, Feb 2001
...dioxide E.L.V. Goetheer, M.W AL. Baars, L.J.P. van den Broeke, E.W.
Meijer, J.T F. Keurentjes 4634 Supercritical water oxidation (SCWO)
for poly( ethylene terephthalate) (PET) industry effluents M.J. Cocero, E.
Alonso, R. TorÃo, D. Vallelado, T. Sanz. F Fih-Pnlnnrn...
120.
SUWOX--a
facility for the destruction of chlorinated hydrocarbons Casal, V. / Schmidt, H., The Journal of Supercritical Fluids,
Jun 1998
...resists the attack of hydrochloric acid under SCWO conditions.
Tlle i`acility is equipped...water inside an altlmina reactol where the SCWO
destructiotl takes place, and an inert...C) in the presence o` oxygen [ I
] The SCWO process brings together water, organics...
121.
Oxidation
of 2,4-dichlorophenol in supercritical water Kuen, S.L. / Wang, H.P. / Li, M.C., Chemosphere, Apr 1998
...p-dioxin, from supercritical water oxidation (SCWO) of DCP at
673 K werv determined. We also...B1998 Etsevier Science Ltd Yey words: SCWO,
dichlorophenol, wer air oxidation, by...that the supercritical water
oxidation (SCWO) process is very adaptable to meet the...
122.
Oxidation
kinetics for methane/methanol mixtures in supercritical water Savage, P.E. / Rovira, J. / Stylski, N. / Martino, C.J., The
Journal of Supercritical Fluids, Apr 2000
...models for supercritical water oxidation (SCWO). Moreover, these
results show that a mechanism-based...Introduction Supercritical water
oxidation (SCWO) is a technology for treating organic wastes...c
=218 atm.). To design and optimize an SCWO process, it is desirable
to possess mathematical...
123.
Supercritical
water oxidation of high concentrations of phenol Matsumura, Y. / Nunoura, T. / Urase, T. / Yamamoto, K., Journal
of Hazardous Materials, Apr 2000
...Introduction Supercritical water oxidation (SCWO) is a promising
technology for treatment...compounds. The high efficiency with which SCWO
decomposes stable organic compounds with...can be decomposed to less than
1% using SCWO at 673 K. It is known that at temperatures...
124.
Production
of useful organic matter from sludge using hydrothermal treatment Shanableh, A., Water Research, Feb 2000
...achieved using supercritical water oxidation (SCWO).
Accordingly, hydrothermal treatment using SubCWO and SCWO can
provide a useful sludge management option...SubCWO) and supercritical
water oxidation (SCWO). Hydrothermal oxidation generates
superior...
125.
An
alternative method of oxidizing aqueous waste in supercritical water:
oxygen supply by means of electrolysis Misch, B. / Firus, A. / Brunner, G., The Journal of
Supercritical Fluids, Jun 2000
...the water needed to be cleaned. Supercritical water oxidation (SCWO)
is preferentially used for aqueous waste streams with too low...not only
in scientific but also in industrial fields [6,7] . SCWO is an
efficient treatment of polycyclic aromatic hydrocarbons...
126.
[Investigation
on the elimination of organic substances in urine by supercritical water
oxidation] T Wang / M Yang / B Xiang / Z Shen, Space Med Med Eng (Beijing),
Oct 1997
Application of Supercritical Water Oxidation (SCWO) to processing
of human metabolic wastes of Controlled Ecological...substance elimination
in urine and recover potable water. The SCWO of simulated urine was
investigated with oxygen as the oxidant...
127.
Thiodiglycol
hydrolysis and oxidation in sub- and supercritical water Lachance, R. / Paschkewitz, J. / DiNaro, J. / Tester, J.W., The
Journal of Supercritical Fluids, Nov 1999
...Introduction Supercritical water oxidation (SCWO) is an
efficient and clean technology for...oxidation reactions. A detailed
description of SCWO reactions can be found in reviews by
Thomason...et al. [2] and Savage et al. [3,4] . The SCWO process
brings together the organic contaminant...
128.
Use
of supercritical fluids for different processes including new
developments-a review Marr, R. / Gamse, T., Chemical Engineering and Processing,
Jan 2000
...these salts result in a sticky mass. Inserting oxygen into
supercritical water causes oxidation (Supercritical Water Oxidation SCWO)
and reaction rates are very high because a lot of substances are
completely miscible with water under these conditions and therefore...
129.
Factors
controlling corrosion in high-temperature aqueous solutions: a
contribution to the dissociation and solubility... Kritzer, P. / Boukis, N. / Dinjus, E., The Journal of
Supercritical Fluids, Jul 1999
...organic wastes (supercritical water oxidation SCWO) [21-24] . In
parallel with the increasing...phosphato complexes [51,54] . The process
of SCWO brought a renaissance of corrosion
investigations...concentrations of dissolved compounds. In the SCWO
process, hazardous organic material (e...
130.
Interferometric
Measurements of Gas Diffusivity in Supercritical Water Kuge, K. / Murayama, Y. / Honda, T. / Kato, Y. / Yoshizawa, Y., Progress
in Nuclear Energy, Jan 2000
...Lide D. R. (1975), Handbook of Chemistry and Physics, 56'* Ed., CRC
Press, New York. Oe T. (1997), Waste Water Treatment by SCWO. J. of
Japan Institute of Energy 76, 868. Saito S. (1996), The Science and
Technology of Supercritical Fluids, Sankyo Business...
131.
Wet
air oxidation: past, present and future Luck, F., Catalysis Today, Oct 1999
...contrast to supercritical water oxygen (SCWO), a complete
mineralization of the waste...results obtained in the first commercial SCWO
unit, which treats wastes containing long-chain...and Ti have been shown
to be stable in SCWO conditions and should be selected as
catalyst...
132.
Low
temperature oxidation of ammonia to nitrogen in liquid phase Ukropec, R. / Kuster, B.F.M. / Schouten, J.C. / van Santen, R.A., Applied
Catalysis B: Environmental, Oct 1999
...et al. [25] studied ammonia oxidation in supercritical water (SCWO)
in the temperature range of 530-700 C at 24.6 MPa. They found...10% in a
tubular reactor at 680 C. An evaluation of catalytic SCWO was
performed in the work of Ding et al. [26] . The same author...
133.
Decomposition
of 2-aminoethanol in sub- and supercritical water with/without hydrogen
peroxide Funazukuri, T. / Takahashi, M., Fuel, Jul 1999
...Decomposition 1 Introduction Supercritical water oxidation (SCWO)
has been increasingly paid attention as a new...without catalysts. There
are extensive reviews on SCWO [4] and wet oxidation [5] . In SCWO
of various materials, the decomposition behaviour...
134.
Optimization
models for determining nitric acid equilibria in supercritical water Ziegler, K.J. / Lasdon, L. / Chlistunoff, J. / Johnston, K.P., Computers
& Chemistry, Sep 1999
...et al., 1980 Miller and Bowman, 1989 Odenbrand et al., 1986 ).
Hydrothermal oxidation (HO), or supercritical water oxidation (SCWO)
( Gloyna and Li, 1993 Tester et al., 1993 ), produces less NO x species
than incineration due to thermodynamic and kinetic arguments...
135.
A
hard-sphere volume-translated van der Waals equation of state for
supercritical process modeling 1. Pure components Kutney, M.C. / Dodd, V.S. / Smith, K.A. / Herzog, H.J. / Tester, J.W.,
Fluid Phase Equilibria, Feb 1997
...modeling supercritical water oxidation (SCWO) of liquid and
slurried organic wastes. Kinetic and flow simulations of the SCWO
process require accurate predictions...Pr 0.35) which is of importance in SCWO
processes. To preserve simplicity and...
136.
Supercritical
water oxidation of polychlorinated biphenyls using hydrogen peroxide Hatakeda, K. / Ikushima, Y. / Sato, O. / Aizawa, T. / Saito, N., Chemical
Engineering Science, Jul 1999
...same conditions. Furthermore, in a flow-reactor system in addition to
the batch-reactor system, supercritical water oxidation (SCWO) of
polychlorinated biphenyls (PCBs) such as 3-PCB and Kanechlor KC-300
(KC-300) using hydrogen peroxide was carried out at 30...
137.
Corrosion
Screening Tests of High-Performance Ceramics in Supercritical Water
Containing Oxygen and Hydrochloric Acid Boukis, N. / Claussen, N. / Ebert, K. / Janssen, R. / Schacht, M., Journal
of the European Ceramic Society, Jan 1997
...simulated supercritical lteater oxidation (SCWO) environn2ent lt
as sneasured. Supercritival...ric acid 11as used to simulate tl~pical SCWO
con- ditions after tl2e decon2position...promising new technology' 2 often
called the SCWO process. Under these conditions oxygen...
138.
Deuteration
of hexane by 2HCl in supercritical deuterium oxide Yang, Y. / Evilia, R.F., The Journal of Supercritical Fluids,
Jun 1999
...Introduction The potential of supercritical water oxidation (SCWO)
for the environmentally benign destruction of organic wastes...importance
in understanding the physical and chemical ramifications of SCWO
and other reactions in this incompletely characterized medium...
139.
An
approach to legal reasoning based on a hybrid decision-support system Pal, K., Expert Systems with Applications, Jul 1999
This paper describes argument structures to generate plausible
explanations for the conclusions reached by rule-based reasoning (RBR),
and provides a means of integrating with case-based reasoning (CBR). The
area of application is a...
140.
Ternary
phase equilibria for the sodium chloride-sodium sulfate-water system at
200 and 250 bar up to 400oC DiPippo, M.M. / Sako, K. / Tester, J.W., Fluid Phase Equilibria,
Mar 1999
...Introduction Supercritical water oxidation (SCWO) is an emerging
technology for the treatment of aqueous organic waste . SCWO is
defined as oxidation which occurs in...primary sources of inorganic salts
in SCWO processing. First, aqueous wastes containing...
A
Short Enantioselective Synthesis of 1-Deoxy-L-xylulose by Antibody
Catalysis Shabat, D. / List, B. / Lerner, R.A. / Barbas, C.F., Tetrahedron
Letters, Feb 1999
...intadk in X biosynthesis of thiain (vitin B,)' and pyfidoxi (vitnin
B,)3. Both L- md D- enmtiomers = syn0esird by a wii rmEe of Scwo~misms
~m pynvic Kid md L- or D- gly=i*&, srtiwly.' hently [his sugs he in
Xund to k an ems non-~vionA biosynthetic pRCU%Or t...
143.
Corrosion
of zirconia ceramics in acidic solutions at high pressures and
temperatures Schacht, M. / Boukis, N. / Dinjus, E. / Ebert, K. / Janssen, R. /
Meschke, F. / Claussen, N., Journal of the European Ceramic Society,
Dec 1998
...is known as supercritical water oxidation (SCWO). The major
problem for the safe operation of SCWO is the corrosion of the
reactor materials...available on the corrosion of zirconia ceramics in SCWO
environments. Hazlebeck et al reported that...
A
Short Enantioselective Synthesis of 1-Deoxy-L-xylulose by Antibody
Catalysis Shabat, D. / List, B. / Lerner, R.A. / Barbas, C.F., Tetrahedron
Letters, Feb 1999
...intadk in X biosynthesis of thiain (vitin B,)' and pyfidoxi (vitnin
B,)3. Both L- md D- enmtiomers = syn0esird by a wii rmEe of Scwo~misms
~m pynvic Kid md L- or D- gly=i*&, srtiwly.' hently [his sugs he in
Xund to k an ems non-~vionA biosynthetic pRCU%Or t...
143.
Corrosion
of zirconia ceramics in acidic solutions at high pressures and
temperatures Schacht, M. / Boukis, N. / Dinjus, E. / Ebert, K. / Janssen, R. /
Meschke, F. / Claussen, N., Journal of the European Ceramic Society,
Dec 1998
...is known as supercritical water oxidation (SCWO). The major
problem for the safe operation of SCWO is the corrosion of the
reactor materials...available on the corrosion of zirconia ceramics in SCWO
environments. Hazlebeck et al reported that...
144.
A
Combined Modeling and Experimental Approach for Achieving a Simplified
Closed Ecosystem Turc, H.A. / Pintena, J. / Bagarri, P. / Gibiat, F. / Fabreguettes, V.,
Advances in Space Research, Jan 1999
...flow Liquid stacking Gas stacking Inputs / Outputs Seeding Injection,
high C02 v v air ( low C02 weous emuent Injection \ Flonv SCWO
reactor f eRespiratioLHarvest ,/Injection ' Grinding t-'Oxidation
Transpiration 7tercolateWateringDilutionj Liquid emuent Transfer...
145.
Fast
catalytic oxidation of phenol in supercritical water Zhang, X. / Savage, P.E., Catalysis Today, May 1998
...Introduction Supe}critical water oxidation (SCWO) is an emer
ging "green" technology for...industrial wastewater streams [1].
The SCWO process takes advantage of the unique properties...first
commercial facility employing the SCWO process became opera tional
in 1994 [2...
146.
Hydrothermal
oxidation of Navy excess hazardous materials Cohen, L.S. / Jensen, D. / Lee, G. / Ordway, D.W., Waste
Management, Oct 1998
...water and NaHCO3 for neutralizing acidic HTO effluents. Process
description HTO, also known as supercritical water oxidation (SCWO),
is a high pressure oxidation process that blends air, water, and organic
waste material in an oxidizer at temperatures and...
147.
Measurements
of the heat capacity at constant volume of H2O+Na2SO4
in near-critical and supercritical water Abdulagatov, I.M. / Dvoryanchikov, V.I. / Mursalov, B.A. / Kamalov, A.N.,
Fluid Phase Equilibria, Sep 1998
...importance in supercritical water oxidation (SCWO) technology
and other industrial applications...solutions at the conditions
encountered in SCWO and sodium sulfate is one of the most
common...525-535 in prospective applications of SCWO [3]. Adding an
electrolyte to water results...
148.
Supercritical
water oxidation for the destruction of municipal excess sludge and alcohol
distillery wastewater of... Goto, M. / Nada, T. / Ogata, A. / Kodama, A. / Hirose, T., The
Journal of Supercritical Fluids, Jun 1998
...clean solid (metal oxides, salts) and clean gas (0CO2. N ,), SCWO
is a proc~ess where oxidation reaction takes place in water
above...conductance, and solv.ttillg ability 111,12]. We have applied SCWO
~sith hydrogen peroxide as an oxidant to the treatmerlt of sludge...
149.
Studies
on experimental adjuvanted influenza vaccines: comparison of immune
stimulating complexes (IscomsTM) and... Coulter, A. / Wong, T.-Y. / Drane, D. / Bates, J. / Macfarlan, R. /
Cox, J., Vaccine, Jul 1998
...other vaccine s ompo- nents and potential (.ontamimarlts ('e.g.
AilCLj,l- 11 were eluted as discrete pt aks. Vaccine preparation /SCwO)llST~.
Lahoraory-scallh Iscomlt' X inz ~herc prepared hasically iry the ml~lllod
o' ML in / ell.4'. Briefly. to the d kired all...
150.
Product
distribution and reaction pathways for methylene chloride hydrolysis and
oxidation under hydrothermal... Marrone, P.A. / Gschwend, P.M. / Swallow, K.C. / Peters, W.A. / Tester,
J.W., The Journal of Supercritical Fluids, Jul 1998
...Methylene chloride Hydrolysis: Oxidatil)ll Supercritical water:
Reaction pathways 1. Introduction Oxidation in supercritical water (SCWO)
shovvs strong promise as an innovative and effective means ,9f destroying
hazardous organic coln * Corresponding author. Fax...
151.
Phenol
oxidation kinetics in supercritical water Oshima, Y. / Hori, K. / Toda, M. / Chommanad, T. / Koda, S., The
Journal of Supercritical Fluids, Jun 1998
...account, a more detailed kinel:ic . . L . . analysls IS stlll under
Investlgat:lon. 4. Conclusions The kinetic parameters in SCWO of
phenol were experimentally determined. By regression analysis, the global
rate of phenol disappearance was found tc~ be proportional...
152.
Chemical
reactions and phase equilibria of model halocarbons and salts in sub- and
supercritical water (200-300 bar,... Tester, J.W. / Marrone, P.A. / DiPippo, M.M. / Sako, K. / Reagan, M.T.
/ Arias, T. / Peters, W.A., The Journal of Supercritical Fluids,
Jun 1998
Experimental data and theoretical predictions of hydrolysis reaction
kinetics of model halocarbons and phase equilibria of their associated
neutralized salt reaction products are reported for a range of
hydrothermal conditions....
153.
Oxidation
rates of common organic compounds in supercritical water Rice, S.F. / Steeper, R.R., Journal of Hazardous Materials,
Apr 1998
...Introduction Supercritical water oxidation (SCWO) is a
developing hazardous-waste-treatment...chemical/radiological mixed waste.
The SCWO process is conceptually simple [1-3]. Organic...inorganic
acid anions. The development of SCWO technology depends on solving
several materials...
154.
Incorporation
of Parametric Uncertainty into Complex Kinetic Mechanisms: Application to
Hydrogen Oxidation in... Phenix, B.D. / Dinaro, J.L. / Tatang, M.A. / Tester, J.W. / Howard, J.B.
/ Mcrae, G.J., Combustion and Flame, Jan 1998
...Background Supercritical water oxidation (SCWO) is a thermally
based waste treatment technology...critical point of water (374C, 221
bar). SCWO has been shown to be an effective means...pilot and
production scale units. In the SCWO process, aqueous waste is
brought into...
155.
A
reduced mechanism for methanol oxidation in supercritical water Brock, E.E. / Savage, P.E. / Barker, J.R., Chemical Engineering
Science, Mar 1998
...1996) as being the fastest for methanol SCWO. The two additional
reactions that emerge...provide a complete mechanism for methanol SCWO,
how- ever, because they do not include...tions. It is well known that
combustion and SCWO kinetics often exhibit an induction period...
156.
Kinetics
and mechanism of methane oxidation in supercritical water Savage, P.E. / Jianli, Y. / Stylski, N. / Brock, E.E., The
Journal of Supercritical Fluids, Apr 1998
...observe that the DCKM predicts methane to be more reactive under SCWO
conditions than it was observed to be experimentally. The
experimental...validating the mechanism and then using it to learn more
about the SCWO chemistry. Accordingly, we saw no merit in tuning
the model parameters...
157.
Oxidation
of methanol over iron oxide based aerogels in supercritical CO2 Wang, C.-T. / Willey, R.J., Journal of Non-Crystalline Solids,
Apr 1998
...enhanced oil recovery using supercritical CO 2 , and paraffin
isomerization in supercritical fluids . Supercritical water oxidation (SCWO)
is a rapidly developing technology for the destruction of a wide variety
of organic hazardous wastes . Oxidation of aromatic...
158.
Catalytic
wet oxidation of phenol over a Pt/TiO2 catalyst Maugans, C.B. / Akgerman, A., Water Research, Dec 1997
...WAO), supercriti- cal water oxidation (SCWO), and catalytic wet
oxidation (CWO). WAO...reaction effluent requiring further treatment. SCWO
occurs at operating conditions above the...point of water (Pc = 218 atm,
TC = 374OC). SCWO yields complete and rapid oxidation of...
159.
Hydrothermal
decomposition and oxidation of p-nitroaniline in supercritical water Dong, S.L. / Kye, S.P. / Young, W.N. / Kim, Y.-C. / Choul, H.L., Journal
of Hazardous Materials, Oct 1997
...capability of supercritical water oxidation (SCWO) has been
shown by several works [1-4...critical to more comprehensive uses of SCWO
process. As noted in a previous study...nitrogen (N)-con- taining
compounds by SCWO is of particular concern in two respects...
Molecular
Simulation Study of Speciation in Supercritical Aqueous NaCl Solutions Chialvo, A.A. / Cummings, P.T. / Simonson, J.M. / Mesmer, R.e., Journal
of Molecular Liquids, Nov 1997
...attractive solvent and reaction medium for complete oxidation of
hazardous wastes [3-6], known as the supercritical water oxidation (SCWO)
process. The unique combination of the dissolving power of a liquid
combined with the transport properties of a gas and the...
162.
New
reactor system for supercritical water oxidation and its application on
phenol destruction Koo, M. / Lee, W.K. / Lee, C.H., Chemical Engineering Science,
Apr 1997
...INTRODLJCTION Supercritical water oxidation (SCWO) is an
excellent waste-treatment process...into carbon dioxide and water. The
idea of SCWO for wastewater treat- ment appeared in...projects for
wastewater treatment using SCWO are under opera- tion in the U.S.A.
and...
163.
Separation
of metal oxides from supercritical water by crossflow microfiltration Goemans, M.G.E. / Tiller, F.M. / Lixiong, L. / Gloyna, E.F., Journal
of Membrane Science, Feb 1997
...1995. The supercritical water oxidation (SCWO) pro- cess is an
effective treatment technology...124 (1997) l29 145 or generated in the SCWO
process-may create a corrosive and erosive...the nature of crossflow
filtration under SCWO conditions dictates special design
considerations...
164.
Decomposition
of nitrobenzene in supercritical water Dong, S.L. / Sang, D.P., Journal of Hazardous Materials, Nov
1996
...Introduction Supercritical water oxidation (SCWO) is a promising
waste treatment process...hazardous organic substances. The early SCWO
works have demonstrated that high destruction...1-4]. As the destruction
capability of SCWO has been demon- strated by these early...
165.
Oxidation
reactors for water and wastewater treatment Po, L.Y., Water Science and Technology, Jan 1997
...concentrations in the wastewater. For supercritical operations (SCWO),
inorganic compounds (e.g. salts) are virtually insoluble in...where
normally immiscible compounds fomm homogeneous mixtures. SCWO
reactors will operate homogeneously, thus eliminating mass transfer...
166.
Methanol
and Hydrogen Oxidation Kinetics in Water at Supercritical States Alkam, M.K. / Pai, V.M. / Butler, P.B. / Pitz, W.J., Combustion
and Flame, Jul 1996
...computational fluid dynamic (CFD) modeling efforts in SCWO, a
two-step reduced reaction mechanism was constructed...the jth reaction
step (kmol/m3-s) INTRODUCTION SCWO Background In supercritical
water oxidation (SCWO), di- lute organics (2%-lOSo organic by
weight...
167.
Recycling
of inorganic nutrients for hydroponic crop production following
incineration of inedible biomass Bubenheim, D.L. / Wignarajah, K., Advances in Space Research,
Jan 1997
...The three primary physical/chemical technologies currently being
investigated are incineration, super critical water oxidation (SCWO),
and steam reformation (2,4). The suitability of the products resulting
from processing of wastes utilizing these technologies...
168.
The
Relationship Between Electrochemical Behaviour and In-service Corrosion of
WC Based Cemented Carbides Human, A.M. / Exner, H.E., International Journal of Refractory
Metals and Hard Materials, Jan 1997
In long-life applications, the corrosion properties of cemented carbides
can have a large influence on overall performance. Cemented carbides with
improved corrosion resistance have been developed and are now commercially
available....
169.
Precipitation
of sodium chloride and sodium sulfate in water from sub- to supercritical
conditions: 150 to 550 oC, 100... Armellini, F.J. / Tester, J.W. / Hong, G.T., The Journal of
Supercritical Fluids, Sep 1994
...during the supercritical water oxidation (SCWO) waste treatment
process were performed...missions. 5-7 Supercritical-wateroxidation (SCWO)
is defined as oxidation that takes place...ternary system at apressure rel-
evant to the SCWO process can be formed.Figure 12 shows
isothermal...
170.
The
solubility of 1:1 nitrate electrolytes in supercritical water Dell'Orco, P. / Eaton, H. / Reynolds, T. / Buelow, S., The
Journal of Supercritical Fluids, Sep 1995
...In this region, the hydrothermal treatment process in which oxidation
occurs is known as supercritical-wateroxidation (SCWO).SCWO
has been shown on laboratory scales to be an efficient method for the
treatment of hazardous organic compounds. **2 At...
171.
Supercritical
water oxidation of acetic acid by potassium permanganate Chang, K.-C. / Li, L. / Gloyna, E.F., Journal of Hazardous
Materials, Jan 1993
Supercritical water oxidation (SCWO) of acetic acid by potassium
permanganate (KMnO"4) was studied. The experiments were performed in
a batch reactor at temperatures and pressures, respectively, ranging from
400 ^oC to 460 ^oC and from 275...
172.
Two-phase
ozonation of chlorinated organics Bhattacharyya, D. / Van Dierdonck, T.F. / West, S.D. / Freshour, A.R.,
Journal of Hazardous Materials, Apr 1995
...without UV), and high temperature and pressure operations such as wet
air oxidation (WAO) and supercritical water oxidation (SCWO) [1,2].
* Corresponding author. Tel: 606257-2794. Fax: 606257-7251.
0304-3894/95/$09.50 ( 1995 Elsevier Science B.V., All rights...
173.
On-line
failure diagnosis for compression refrigeration plants Grimmelius, H.T. / Woud, J.K. / Been, G., International Journal
of Refrigeration, Jan 1995
...variables \X, / ~F , REFRIGERANT X 4 V Pci Pcrkc Poil - pco 8 Peso 6
Apf 5 ~cj10 (Jco - Ooil.l condo1 2 Oexpj 1 3 evi I 4 f)evo I S Scwo
l 6 Ocwi 1 7 (Jchwi1 8 chwe lc ll vref amb The system boundary is defined
around the chiller, as indicated in Fi0ure 4. This...
174.
Supercritical
water oxidation: an engineering update Gloyna, E.F. / Li, L., Waste Management, Jan 1993
...concepts of supercritical water oxidation (SCWO), associated
engineering research, and...During the last few years a growing body of SCWO
knowledge has been assembled. A number...requirements, and process
integration. SCWO technology relies on the unique properties...
175.
Fate
of chromium and lead in supercritical water oxidation environment Gloyna, E.F., Waste Management, Jan 1994
...lead in supercritical water oxidation (SCWO) environments, and
b) the effect of additives...ids, the fate of chromium and lead in SCWO
envi- ronments as oxidation and corrosion...reaction species on the
potential toxicity of SCWO effluents is not clearly understood.
Such...
176.
Analysis
of post-combustion products from waste-derived fuel by FTIR spectroscopy Lindner, J.S. / Cook, R.L., Waste Management, Jan 1994
...lead in supercritical water oxidation (SCWO) environments, and
b) the effect of additives...ids, the fate of chromium and lead in SCWO
envi- ronments as oxidation and corrosion...reaction species on the
potential toxicity of SCWO effluents is not clearly understood.
Such...
177.
Experimental
methods for studying salt nucleation and growth from supercritical water Armellini, F.J. / Teste, J.W., The Journal of Supercritical
Fluids, Dec 1991
...formation during Supercritical Water Oxidation (SCWO), which is
an emerging waste treatment...and size of particles formed during the SCWO
process. Keywords:supercritical water...missions. 4~5 Supercriticalwater
oxidation (SCWO) is defined as oxidation that takes place...
178.
Catalytic
supercritical water oxidation of 1,4-dichlorobenzene Jin, L. / Ding, Z. / Abraham, M.A., Chemical Engineering Science,
Jun 1992
...oxidation in supercritical water, and catalytic SCWO at 374 C.
F7 Catalytic supercritical water...any reaction time, - although catalytic
SCWO provided s -~ comparable conversion after...surface reaction
with adsorbed oxygen. In SCWO (even in the absence of the
catalyst...
179.
Subcritical
and supercritical water oxidation of CELSS model wastes Takahashi, Y. / Wydeven, T. / Koo, C., Advances in Space
Research, Jan 1989
...WO) and supercrltlcal water oxidation (SCWO) are presently the
most hopeful candidate...the waste treatment techniques of WO and SCWO
still have many problems to be solved...and nitrogen are important because
WO or SCWO Is intended to work as a complete oxidizer...
180.
Incineration
for resource recovery in a closed ecological life support system Upadhye, R.S. / Wignarajah, K. / Wydeven, T., Environment
International, Jan 1993
...oxidation, and supercritical water oxidation (SCWO). Nonthermal
processes under investigation...Jagow 1972). Waste destruction by the SCWO
process makes use of water in its supercritical...needed to yield a
sterile product and 3) The SCWO process operates at a lower
temperature...
181.
Variation
of mean SiO bond lengths in silicon-oxygen octahedra Baur, W.H., Journal of Solid State Chemistry, Dec 1977
...coordination against oxygen is 0.407 A. Recently Reid et al. (1) have
reported on the synthesis of high-pressure pyrochlore-type ScWO!,4!
and Iny'Sif'O!,4' (the superscripts refer to the coordination numbers of
the atoms). This adds two more compounds to the...
The
telephone in question: Questions on communication Claisse, G. / Rowe, F., Computer Networks and ISDN Systems,
Jan 1987
The household use of the telephone is not well known. Who telephones? Why?
To whom? Over and above the diversity of telephone conversations, is it
possible to identify different telephone habits? Using a survey of
telephone calls (7252...
184.
Spectrochemical
Determination of Scandium in Silicate Rocks Kvalheim, A. / Streck, L.W., Spectrochimica Acta, Jan 1939
...04 ^-o-e / / of the lines above the cathode continuum in the
photographic spefctrum, because in the cathode n.a A /Sc win v'Scwo
layer method the image of the arc is focused on the spectrograph slit,
which is therefore not uniformly illuminated along its...
185.
Optimal
chain partitions of trees Misra, J. / Tarjan, R.E., Information Processing Letters,
Sep 1975
...University esf Texas at ..4us#», Awtft Texar 787th USA Ead.-e
TAttJAN a D1epØtwnt.of EkcdÃØl
Engfneeringáad Conkpt4r Scwo.saes.&tat the
ñlectrnnics Rewmh LabØntory, 4lfAtfrerdty of
ØfornTa at BErkeley, Berke?ey, C,A 94?20, llSA ~r ttaoeÃ...
A
convenient setting for differential calculus Seip, U., Journal of Pure and Applied Algebra, Jan 1979
Barr Received February 1977 Cartesian closed categories play an important
rôle in many aspects of mathematics. They appear in
algebraic geometry, in logic, in topology. Quite naturally one is tempted
to use this notion also for differential calculus.
188.
Electronic
structure of evaporated and annealed tungsten oxide films studied with UPS Hochst, H. / Bringans, R.D., Applications of Surface Science,
Jul 1982
...during the annealing 6~0 6.0T 5.5 5 ~ EF~0J ‘ 31
EFaCIt ‘31 3.0 A — 3.0 —~~‘
‘\ ~ I aWO~ SCWO 3.5 pc-W03 4 ‘0
I , 4,0 • 4.0 a-w03 300 500 700 900 1100 300 500 7~0
900 1100 ANNEAL TEMP~ (K) ANNEAL TEMP(K) Fig...
