WorldWideScience

Sample records for catalytic wet air

  1. Catalytic wet Air Oxidation of o-Chlorophenol in Wastewater

    Institute of Scientific and Technical Information of China (English)

    徐新华; 汪大翬

    2003-01-01

    Catalytic wet air oxidation (CWAO) was investigated in laboratory-scale experiments for the treatment of o-chlorophenol in wastewater. Experimental results showed that wet air oxidation (WAO) process in the absence of catalyst was also effective for o-chlorophenol in wastewater treatment. Up to 80% of the initial CODCr was removed by wet air oxidation at 270℃ with twice amount of the required stoichiometric oxygen supply. At temperature of 150℃, the removal rate of CODCr was only 30%. Fe2(SO4)3, CuSO4, Cu(NO3)2 and MnSO4 exhibited high catalytic activity. Higher removal rate of CODCr was obtained by CWAO. More than 96% of the initial CODCr was removed at 270℃ and 84.6%-93.6% of the initial CODCr was removed at 150℃. Mixed catalysts had better catalytic activity for the degradation of o-chlorophenol in wastewater.

  2. Homogeneous catalytic wet air oxidation for the treatment oftextile wastewaters

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An extensive series of experiments was carried out in order to identify suitable catalysts to boost the reaction rate of wet air oxidation of real textile wastewaters at relatively mild temperature and pressure. Experimental results indicated that all catalysts tested in this investigation had shown an impressive increase in the initial COD and TOC removal rate as well as the COD and TOC removal levels in two hours reaction. Among all the catalysts tested, copper salts were more effective than the rest. Anions of the salt soluffonsalso played a role in the catalytic process with nitrate ions having better effect than sulfate ions. Hence copper nitrates were more effective than copper sulfates. It was also found that a mixture of salts with different metals performed better than either of the component single salt alone.

  3. Catalytic wet air oxidation for the treatment of emulsifying wastewater

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jian-fu; CHEN Ling; LU Yi-cheng; TANG Wen-wei

    2005-01-01

    The wet air oxidation (WAO) and catalytic WAO (CWAO) of the high strength emulsifying wastewater containing nonionic surfactants have been investigated in terms of COD and TOC removal. The WAO and homogeneous CWAO processes were carried out at the temperature from 433 K to 513 K, with initial oxygen pressure 1.2 MPa. It was found that homogeneous catalyst copper(Cu ( NO3 )2 )had an fairly good catalytic activity for the WAO process, and the oxidation was catalyzed when the temperature was higher than 473 K.Moreover, several heterogeneous catalysts were proved to be effective for the WAO process. At the temperature 473 K, after 2 h reaction,WAO process could achieve about 75% COD removal and 66% TOC removal, while catalysts Cu/Al2O3 and Mn-Ce/Al2O3 elevated the COD removal up to 86%-89% and that of TOC up to 82%. However, complete elimination of COD and TOC was proved to be difficult even the best non-noble catalyst was used. Therefore, the effluent from WAO or CWAO process need to be further disposed. The bioassay proved that the effluent from WAO process was amenable to the biochemical method.

  4. Catalytic wet air oxidation of chlorophenols over supported ruthenium catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Li Ning [Institut de recherches sur la catalyse et l' environnement de Lyon (IRCELYON), UMR 5256, CNRS/Universite Claude Bernard Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex (France); Descorme, Claude [Institut de recherches sur la catalyse et l' environnement de Lyon (IRCELYON), UMR 5256, CNRS/Universite Claude Bernard Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex (France)]. E-mail: claude.descorme@catalyse.cnrs.fr; Besson, Michele [Institut de recherches sur la catalyse et l' environnement de Lyon (IRCELYON), UMR 5256, CNRS/Universite Claude Bernard Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex (France)

    2007-07-31

    A series of noble metal (Pt, Pd, Ru) loaded zirconia catalysts were evaluated in the catalytic wet air oxidation (CWAO) of mono-chlorophenols (2-CP, 3-CP, 4-CP) under relatively mild reaction conditions. Among the investigated noble metals, Ru appeared to be the best to promote the CWAO of CPs as far as incipient-wetness impregnation was used to prepare all the catalysts. The position of the chlorine substitution on the aromatic ring was also shown to have a significant effect on the CP reactivity in the CWAO over 3 wt.% Ru/ZrO{sub 2}. 2-CP was relatively easier to degradate compared to 3-CP and 4-CP. One reason could be the higher adsorption of 2-CP on the catalyst surface. Further investigations suggested that 3 wt.% Ru/ZrO{sub 2} is a very efficient catalyst in the CWAO of 2-CP as far as high 2-CP conversion and TOC abatement could still be reached at even lower temperature (393 K) and lower total pressure (3 MPa). Additionally, the conversion of 2-CP was demonstrated to increase with the initial pH of the 2-CP solution. The dechlorination reaction is promoted at higher pH. In all cases, the adsorption of the reactants and the reaction intermediates was shown to play a major role. All parameters that would control the molecule speciation in solution or the catalyst surface properties would have a key effect.

  5. Degradation of paracetamol by catalytic wet air oxidation and sequential adsorption - Catalytic wet air oxidation on activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Quesada-Penate, I. [Universite de Toulouse, INPT, UPS, Laboratoire de Genie Chimique, 4, Allee Emile Monso, F-31432 Toulouse (France); CNRS, Laboratoire de Genie Chimique, F-31432 Toulouse (France); Julcour-Lebigue, C., E-mail: carine.julcour@ensiacet.fr [Universite de Toulouse, INPT, UPS, Laboratoire de Genie Chimique, 4, Allee Emile Monso, F-31432 Toulouse (France); CNRS, Laboratoire de Genie Chimique, F-31432 Toulouse (France); Jauregui-Haza, U.J. [Instituto Superior de Tecnologias y Ciencias Aplicadas, Ave. Salvador Allende y Luaces, Habana (Cuba); Wilhelm, A.M.; Delmas, H. [Universite de Toulouse, INPT, UPS, Laboratoire de Genie Chimique, 4, Allee Emile Monso, F-31432 Toulouse (France); CNRS, Laboratoire de Genie Chimique, F-31432 Toulouse (France)

    2012-06-30

    Highlights: Black-Right-Pointing-Pointer Three activated carbons (AC) compared as adsorbents and oxidation catalysts. Black-Right-Pointing-Pointer Similar evolution for catalytic and adsorptive properties of AC over reuses. Black-Right-Pointing-Pointer Acidic and mesoporous AC to be preferred, despite lower initial efficiency. Black-Right-Pointing-Pointer Oxidative degradation of paracetamol improves biodegradability. Black-Right-Pointing-Pointer Convenient hybrid adsorption-regenerative oxidation process for continuous treatment. - Abstract: The concern about the fate of pharmaceutical products has raised owing to the increasing contamination of rivers, lakes and groundwater. The aim of this paper is to evaluate two different processes for paracetamol removal. The catalytic wet air oxidation (CWAO) of paracetamol on activated carbon was investigated both as a water treatment technique using an autoclave reactor and as a regenerative treatment of the carbon after adsorption in a sequential fixed bed process. Three activated carbons (ACs) from different source materials were used as catalysts: two microporous basic ACs (S23 and C1) and a meso- and micro-porous acidic one (L27). During the first CWAO experiment the adsorption capacity and catalytic performance of fresh S23 and C1 were higher than those of fresh L27 despite its higher surface area. This situation changed after AC reuse, as finally L27 gave the best results after five CWAO cycles. Respirometry tests with activated sludge revealed that in the studied conditions the use of CWAO enhanced the aerobic biodegradability of the effluent. In the ADOX process L27 also showed better oxidation performances and regeneration efficiency. This different ageing was examined through AC physico-chemical properties.

  6. CATALYTIC WET AIR OXIDATION OF INDUSTRIAL EFFLUENTS USING A Pt CATALIST SUPPORTED ON MULTIWALLED CARBON NANOTUBES

    OpenAIRE

    Gabriel Ovejero; José L. Sotelo; Araceli Rodríguez; Ana Vallet; Juan García

    2011-01-01

    In this work, catalytic wet air oxidation in a batch reactor was studied by catalytic wet air oxidation to treat industrial wastewater. Basic Yellow 11, a basic dye, was employed as a model compound and platinum supported over multi-walled nanotubes (Pt/MWNT) was used as catalyst. Additionally, two different industrial wastewaters were tested. The results prove the high effectivity of this treatment, showing high extents of total organic carbon and toxicity removal of the final effluent. We c...

  7. Pretreatment of apramycin wastewater by catalytic wet air oxidation

    Institute of Scientific and Technical Information of China (English)

    YANG Shao-xia; FENG Yu-jie; WAN Jia-feng; LIN Qing-ying; ZHU Wan-peng; JIANG Zhan-peng

    2005-01-01

    The pretreatment technology of wet air oxidation(WAO) and coagulation and acidic hydrolysis for apramycin wastewater was investigated in this paper. The COD, apramycin, NH4+ concentration, and the ratio of BOD5/COD were analyzed, and the color and odor of the effluent were observed. WAO of apramycin wastewater, without catalyst and with RuO2/Al2 O3 and RuO2-CeO2/Al2 O3 catalysts, was carried out at degradation temperature of 200℃ and the total pressure of 4 MPa in a 1 L batch reactor. The result showed that the apramycin removals were respectively 50.2% and 55.0%, COD removals were 40.0% and 46.0%, and the ratio of BOD5/COD was increased to 0.49 and 0.54 with RuO2/Al2 O3 and RuO2-CeO2/Al2 O3 catalysts in catylytic wet air oxidation(CWAO) after the reaction of 150 min. With the pretreatment of coagulation and acidic hydrolysis, COD and apramycin removals were slight decreased, and the ratio of BOD5/COD was increased to 0.45, and the effluents was not suitable to biological treatment. The color and odor of the wastewater were the apramycin wastewater. The addition of CeO2 could promote the activity and stability of RuO2/Al2 O3 in WAO of apramycin wastewater.

  8. Catalytic and non-catalytic wet air oxidation of sodium dodecylbenzene sulfonate: kinetics and biodegradability enhancement.

    Science.gov (United States)

    Suárez-Ojeda, María Eugenia; Kim, Jungkwon; Carrera, Julián; Metcalfe, Ian S; Font, Josep

    2007-06-18

    Wet air oxidation (WAO) and catalytic wet air oxidation (CWAO) were investigated as suitable precursors for the biological treatment of industrial wastewater containing sodium dodecylbenzene sulfonate (DBS). Two hours WAO semi-batch experiments were conducted at 15 bar of oxygen partial pressure (P(O2)) and at 180, 200 and 220 degrees C. It was found that the highest temperature provides appreciable total organic carbon (TOC) and chemical oxygen demand (COD) abatement of about 42 and 47%, correspondingly. Based on the main identified intermediates (acetic acid and sulfobenzoic acid) a reaction pathway for DBS and a kinetic model in WAO were proposed. In the case of CWAO experiments, seventy-two hours tests were done in a fixed bed reactor in continuous trickle flow regime, using a commercial activated carbon (AC) as catalyst. The temperature and P(O2) were 140-160 degrees C and 2-9 bar, respectively. The influence of the operating conditions on the DBS oxidation, the occurrence of oxidative coupling reactions over the AC, and the catalytic activity (in terms of substrate removal) were established. The results show that the AC without any supported active metal behaves bi-functional as adsorbent and catalyst, giving TOC conversions up to 52% at 160 degrees C and 2 bar of P(O2), which were comparable to those obtained in WAO experiments. Respirometric tests were completed before and after CWAO and to the main intermediates identified through the WAO and CWAO oxidation route. Then, the readily biodegradable COD (COD(RB)) of the CWAO and WAO effluents were found. Taking into account these results it was possible to compare whether or not the CWAO or WAO effluents were suitable for a conventional activated sludge plant inoculated with non adapted culture. PMID:17363148

  9. Catalytic and non-catalytic wet air oxidation of sodium dodecylbenzene sulfonate: Kinetics and biodegradability enhancement

    International Nuclear Information System (INIS)

    Wet air oxidation (WAO) and catalytic wet air oxidation (CWAO) were investigated as suitable precursors for the biological treatment of industrial wastewater containing sodium dodecylbenzene sulfonate (DBS). Two hours WAO semi-batch experiments were conducted at 15bar of oxygen partial pressure (PO2) and at 180, 200 and 220deg. C. It was found that the highest temperature provides appreciable total organic carbon (TOC) and chemical oxygen demand (COD) abatement of about 42 and 47%, correspondingly. Based on the main identified intermediates (acetic acid and sulfobenzoic acid) a reaction pathway for DBS and a kinetic model in WAO were proposed. In the case of CWAO experiments, seventy-two hours tests were done in a fixed bed reactor in continuous trickle flow regime, using a commercial activated carbon (AC) as catalyst. The temperature and PO2 were 140-160deg. C and 2-9bar, respectively. The influence of the operating conditions on the DBS oxidation, the occurrence of oxidative coupling reactions over the AC, and the catalytic activity (in terms of substrate removal) were established. The results show that the AC without any supported active metal behaves bi-functional as adsorbent and catalyst, giving TOC conversions up to 52% at 160deg. C and 2 bar of PO2, which were comparable to those obtained in WAO experiments. Respirometric tests were completed before and after CWAO and to the main intermediates identified through the WAO and CWAO oxidation route. Then, the readily biodegradable COD (CODRB) of the CWAO and WAO effluents were found. Taking into account these results it was possible to compare whether or not the CWAO or WAO effluents were suitable for a conventional activated sludge plant inoculated with non adapted culture

  10. SPONTANEOUS CATALYTIC WET AIR OXIDATION DURING PRE-TREATMENT OF HIGH-LEVEL RADIOACTIVE WASTE SLUDGE

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D.; Herman, C.; Pareizs, J.; Bannochie, C.; Best, D.; Bibler, N.; Fellinger, T.

    2009-10-01

    Savannah River Remediation, LLC (SRR) operates the Defense Waste Processing Facility for the U.S. Department of Energy at the Savannah River Site. This facility immobilizes high-level radioactive waste through vitrification following chemical pretreatment. Catalytic destruction of formate and oxalate ions to carbon dioxide has been observed during qualification testing of non-radioactive analog systems. Carbon dioxide production greatly exceeded hydrogen production, indicating the occurrence of a process other than the catalytic decomposition of formic acid. Statistical modeling was used to relate the new reaction chemistry to partial catalytic wet air oxidation of both formate and oxalate ions driven by the low concentrations of palladium, rhodium, and/or ruthenium in the waste. Variations in process conditions led to increases or decreases in the total oxidative destruction, as well as partially shifting the preferred species undergoing destruction from oxalate ion to formate ion.

  11. Application of Catalytic Wet Air Oxidation to Treatment of Landfill Leachate on Co/Bi Catalyst

    Institute of Scientific and Technical Information of China (English)

    LI Hai-sheng; LIU Liang; ZHANG Rong; DONG De-ming; LIU Hong-liang; LI Yu

    2004-01-01

    Catalytic wet air oxidation(CWAO) was employed to reduce the organic compounds in landfill leachate and the effects of temperature, oxygen pressure, catalyst dosage, and concentration of the organic compounds on the TOC and CODCr removal rates were studied. The degradation kinetics of landfill leachate was also investigated and an exponential experiential model consisting of four influential factors was established to describe the reduction of the organic compounds in the landfill leachate. Meanwhile, the GC-MS technique was used to detect the components of the organic intermediates for the inference of the decomposition mechanisms of the organic compounds in landfill leachate. The results reveal that the reaction temperature and the catalyst dosage are the most important factors affecting the degradation reaction of the organic compounds and that the principal intermediates confirmed by GC-MS are organic acids at a percentage of more than 88% with no aldehydes or alcohols detected. The decomposition mechanisms of the organic compounds in landfill leachate were inferred based on the GC-MS information as follows: the activated gas phase O2 captured the hydrogen of the organic pollutants to produce free radicals, which then initiated the catalytic reaction. So most of the organic compounds were oxidized into CO2 and H2O ultimately. In general, catalytic wet air oxidation over catalyst Co3O4/Bi2O3 was a very promising technique for the treatment of landfill leachate.

  12. Kinetics study on catalytic wet air oxidation of phenol by several metal oxide catalysts

    Institute of Scientific and Technical Information of China (English)

    WAN Jia-feng; FENG Yu-jie; CAI Wei-min; YANG Shao-xia; SUN Xiao-jun

    2004-01-01

    Four metal oxide catalysts composed of copper (Cu), stannum (Sn), copper-stannum (Cu-Sn) and copper-cerium(Cu-Ce) respectively were prepared by the co-impregnation method, and γ-alumina(γ-Al2O3) is selected as support. A first-order kinetics model was established to study the catalytic wet air oxidation of phenol at different temperature when these catalysts were used. The model simulations are good agreement with present experimental data. Results showed that the reaction rate constants can be significantly increased when catalysts were used, and the catalyst of 6% Cu-10%Ce/γ-Al2O3 showed the best catalytic activity. This is consistent with the result of catalytic wet air oxidation of phenol and the COD removal can be arrived at 98.2% at temperature 210℃, oxygen partial pressure 3 MPa and reaction time 30 min. The activation energies of each reaction with different catalysts are nearly equal, which is found to be about 42 kJ/mol and the reaction in this study is proved to be kinetics control.

  13. Catalytic wet air oxidation of 2-chlorophenol over sewage sludge-derived carbon-based catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Tu, Yuting [Institut de recherches sur la catalyse et l’environnement de Lyon (IRCELYON), CNRS – Université Claude Bernard Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex (France); School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Xiong, Ya; Tian, Shuanghong [School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275 (China); Kong, Lingjun [School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Descorme, Claude, E-mail: claude.descorme@ircelyon.univ-lyon1.fr [Institut de recherches sur la catalyse et l’environnement de Lyon (IRCELYON), CNRS – Université Claude Bernard Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex (France)

    2014-07-15

    Highlights: • A sewage sludge derived carbon-supported iron oxide catalyst (FeSC) was prepared. • FeSC exhibited high catalytic activity in the wet air oxidation of 2-chlorophenol. • A strong correlation was observed between the 2-CP conversion, the iron leaching and the pH. • Using an acetate buffer, the iron leaching was suppressed while keeping some catalytic activity. • A simplified reaction pathway was proposed for the CWAO of 2-CP over the FeSC catalyst. - Abstract: A sewage sludge derived carbon-supported iron oxide catalyst (FeSC) was prepared and used in the Catalytic Wet Air Oxidation (CWAO) of 2-chlorophenol (2-CP). The catalysts were characterized in terms of elemental composition, surface area, pH{sub PZC}, XRD and SEM. The performances of the FeSC catalyst in the CWAO of 2-CP was assessed in a batch reactor operated at 120 °C under 0.9 MPa oxygen partial pressure. Complete decomposition of 2-CP was achieved within 5 h and 90% Total Organic Carbon (TOC) was removed after 24 h of reaction. Quite a straight correlation was observed between the 2-CP conversion, the amount of iron leached in solution and the pH of the reaction mixture at a given reaction time, indicating a strong predominance of the homogeneous catalysis contribution. The iron leaching could be efficiently prevented when the pH of the solution was maintained at values higher than 4.5, while the catalytic activity was only slightly reduced. Upon four successive batch CWAO experiments, using the same FeSC catalyst recovered by filtration after pH adjustment, only a very minor catalyst deactivation was observed. Finally, based on all the identified intermediates, a simplified reaction pathway was proposed for the CWAO of 2-CP over the FeSC catalyst.

  14. Conversion of the refractory ammonia and acetic acid in catalytic wet air oxidation of animal byproducts

    Institute of Scientific and Technical Information of China (English)

    Virginie Fontanier; Sofiane Zalouk; Stéphane Barbati

    2011-01-01

    Wet air oxidation (WAO) and catalytic wet air oxidation (CWAO) of slaughtered animal byproducts (ABPs) were investigated.Two step experiment was carried out consisting ofa non-catalysed WAO run followed by a CWAO run at 170-275℃, 20 MPa, and reaction time 180 min.The WAO (1st step) of sample (5 g/L total organic carbon (TOC)) yielded (82.0 ± 4)% TOC removal and (78.4 ± 13.2)%conversion of the initial organic-N into NH4+-N.Four metal catalysts (Pd, Pt, Rh, Ru) supported over alumina have been tested in catalytic WAO (2nd step) at elevated pH to enhance ammonia conversion and organic matter removal, particularly acetic acid.It was found that the catalysts Ru, Pt, and Rh had significant effects on the TOC removal (95.1%, 99.5% and 96.7%, respectively) and on the abatement of ammonia (93.4%, 96.7% and 96.3%, respectively) with high nitrogen selectivity.The catalyst Pd was found to have the less activity while Pt had the best performance.The X-Ray diffraction analysis showed that the support of catalyst was not stable under the experimental conditions since it reacted with phosphate present in solution.Nitrite and nitrate ions were monitored during the oxidation reaction and it was concluded that CWAO of ammonia in real waste treatment framework was in good agreement with the results obtained from the literature for ideal solutions of ammonia.

  15. Preparation of rare-earth metal complex oxide catalysts for catalytic wet air oxidation

    Institute of Scientific and Technical Information of China (English)

    LI Ning; LI Guangming; YAO Zhenya; ZHAO Jianfu

    2007-01-01

    Catalytic wet air oxidation(CWAO)is one of the most promising technologies for pollution abatement.Developing catalysts with high activity and stability is crucial for the application of the CWAO process.The Mn/Ce complex oxide catalyrsts for CWAO of high concentration phenol containing wastewater were prepared by coprecipitation.The catalyst preparation conditions were optimized by using an orthogonal layout method and single-factor experimental analysis.The Mn/Ce serial catalysts were characterized by Brunauer-Emmett-Teller(BET)analysis and the metal cation leaching was measured by inductively coupled plasma torch-atomic emission spectrometry(ICP-AES).The results show that the catalysts have high catalytic activities even at a low temperature(80℃)and low oxygen partial pressure(0.5 MPa)in a batch reactor.The metallic ion leaching is comparatively low(Mn<6.577 mg/L and Ce<0.6910 mg/L,respectively)in the CWAO process.The phenol,CODCD and TOC removal efficiencies in the solution exceed 98.5% using the optimal catalyst(named CSP).The new catalyst would have a promising application in CWAO treatment of high concentration organic wastewater.

  16. Supported noble metal catalysts in the catalytic wet air oxidation of industrial wastewaters and sewage sludges.

    Science.gov (United States)

    Besson, M; Descorme, C; Bernardi, M; Gallezot, P; di Gregorio, F; Grosjean, N; Minh, D Pham; Pintar, A

    2010-12-01

    This paper reviews some catalytic wet air oxidation (CWAO) investigations of industrial wastewaters over platinum and ruthenium catalysts supported on TiO2 and ZrO2 formulated to be active and resistant to leaching, with particular focus on the stability of the catalyst. Catalyst recycling experiments were performed in batch reactors and long-term stability tests were conducted in trickle-bed reactors. The catalyst did not leach upon treatment of Kraft bleaching plant and olive oil mill effluents, and could be either recycled or used for long periods of time in continuous reactors. Conversely, these catalysts were rapidly leached when used to treat effluents from the production of polymeric membranes containing N,N-dimethylformamide. The intermediate formation of amines, such as dimethylamine and methylamine with a high complexing capacity for the metal, was shown to be responsible for the metal leaching. These heterogeneous catalysts also deactivated upon CWAO of sewage sludges due to the adsorption of the solid organic matter. Pre-sonication of the sludge to disintegrate the flocs and improve solubility was inefficient. PMID:21214003

  17. Development of a Catalytic Wet Air Oxidation Method to Produce Feedstock Gases from Waste Polymers

    Science.gov (United States)

    Kulis, Michael J.; Guerrero-Medina, Karen J.; Hepp, Aloysius F.

    2012-01-01

    Given the high cost of space launch, the repurposing of biological and plastic wastes to reduce the need for logistical support during long distance and long duration space missions has long been recognized as a high priority. Described in this paper are the preliminary efforts to develop a wet air oxidation system in order to produce fuels from waste polymers. Preliminary results of partial oxidation in near supercritical water conditions are presented. Inherent corrosion and salt precipitation are discussed as system design issues for a thorough assessment of a second generation wet air oxidation system. This work is currently being supported by the In-Situ Resource Utilization Project.

  18. Catalytic wet-air oxidation of lignin in a three-phase reactor with aromatic aldehyde production

    OpenAIRE

    Sales F.G.; Abreu C.A.M.; Pereira J. A. F. R.

    2004-01-01

    In the present work a process of catalytic wet air oxidation of lignin obtained from sugar-cane bagasse is developed with the objective of producing vanillin, syringaldehyde and p-hydroxybenzaldehyde in a continuous regime. Palladium supported on g-alumina was used as the catalyst. The reactions in the lignin degradation and aldehyde production were described by a kinetic model as a system of complex parallel and series reactions, in which pseudo-first-order steps are found. For the purpose o...

  19. Catalytic wet-air oxidation of lignin in a three-phase reactor with aromatic aldehyde production

    Directory of Open Access Journals (Sweden)

    Sales F.G.

    2004-01-01

    Full Text Available In the present work a process of catalytic wet air oxidation of lignin obtained from sugar-cane bagasse is developed with the objective of producing vanillin, syringaldehyde and p-hydroxybenzaldehyde in a continuous regime. Palladium supported on g-alumina was used as the catalyst. The reactions in the lignin degradation and aldehyde production were described by a kinetic model as a system of complex parallel and series reactions, in which pseudo-first-order steps are found. For the purpose of producing aromatic aldehydes in continuous regime, a three-phase fluidized reactor was built, and it was operated using atmospheric air as the oxidizer. The best yield in aromatic aldehydes was of 12%. The experimental results were compatible with those values obtained by the pseudo-heterogeneous axial dispersion model (PHADM applied to the liquid phase.

  20. Catalytic Wet Air Oxidation of o-Chlorophenol in Wastewater%邻氯苯酚废水的催化湿式氧化处理

    Institute of Scientific and Technical Information of China (English)

    徐新华; 汪大翚

    2003-01-01

    Catalytic wet air oxidation (CWAO) was investigated in laboratory-scale experiments for the treatmentof o-chlorophenol in wastewater. Experimental results showed that wet air oxidation (WAO) process in the absence ofcatalyst was also effective for o-chlorophenol in wastewater treatment. Up to 80% of the initial CODCr was removedby wet air oxidation at 270℃ with twice amount of the required stoichiometric oxygen supply. At temperatureof 150℃, the removal rate of CODCr was only 30%. Fe2(SO4)3, CuSO4, Cu(NO3)2 and MnSO4 exhibited highcatalytic activity. Higher removal rate of CODCr was obtained by CWAO. More than 96% of the initial CODCrwas removed at 270℃ and 84.6%-93.6% of the initial CODCr was removed at 150℃. Mixed catalysts had bettercatalytic activity for the degradation of o-chlorophenol in wastewater.

  1. Investigation on preparation of CuO-SnO2-CeO2/γ-Al2O3 catalysts for catalytic wet air oxidation process and their catalytic activity for degradation of phenol

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-jun; ZHANG Mi-lin; WAN Jia-feng; XIA Zhi; LIU Xiao-hui; LIU hui

    2008-01-01

    Catalytic Wet Air Oxidation process is an efficient measure for treatment of wastewater with great strength which is not biodegradable. Heterocatalysts now become the key investigation subject of catalytic wet air oxidation process due to their good stability and easy separation. In the paper, CuO-SnOE-CeO2/γ-Al2O3 catalysts are prepared by impregnation method, with SnO2 as a doping component, CuO as an active component, CeO2 as a structure stabilizer, γ-Al2O3 as a substrate. XPS test is carried out to investigate the effect of Sn on the chemical surrounding of Cu and O element on the catalyst surface and their catalytic activity. It is shown that the right do-ping of Sn can increase Cu+ content on the catalyst surface, as a result the quantity of adsorption oxygen is also increased. It is found that Cu + content on the catalyst surface is one of the primary factors that determin catalytic activity of catalyst through analyzing the catalytic wet air oxidation process of phenol.

  2. Toxicity to Daphnia magna and Vibrio fischeri of Kraft bleach plant effluents treated by catalytic wet-air oxidation.

    Science.gov (United States)

    Pintar, Albin; Besson, Michèle; Gallezot, Pierre; Gibert, Janine; Martin, Dominique

    2004-01-01

    Two Kraft-pulp bleaching effluents from a sequence of treatments which include chlorine dioxide and caustic soda were treated by catalytic wet-air oxidation (CWAO) at T=463 K in trickle-bed and batch-recycle reactors packed with either TiO2 extrudates or Ru(3 wt%)/TiO2 catalyst. Chemical analyses (TOC removal, color, HPLC) and bioassays (48-h and 30-min acute toxicity tests using Daphnia magna and Vibrio fischeri, respectively) were used to get information about the toxicity impact of the starting effluents and of the treated solutions. Under the operating conditions, complex organic compounds are mostly oxidized into carbon dioxide and water, along with short-chain carboxylic acids. Bioassays were found as a complement to chemical analyses for ensuring the toxicological impact on the ecosystem. In spite of a large decrease of TOC, the solutions of end products were all more toxic to Daphnia magna than the starting effluents by factors ranging from 2 to 33. This observation is attributed to the synergistic effects of acetic acid and salts present in the solutions. On the other hand, toxicity reduction with respect to Vibrio fischeri was achieved: detoxification factors greater than unity were measured for end-product solutions treated in the presence of the Ru(3 wt%)/TiO2 catalyst, suggesting the absence of cumulative effect for this bacteria, or a lower sensitivity to the organic acids and salts. Bleach plant effluents treated by the CWAO process over the Ru/TiO2 catalyst were completely biodegradable. PMID:14675640

  3. Carbon and nitrogen removal from glucose-glycine melanoidins solution as a model of distillery wastewater by catalytic wet air oxidation.

    Science.gov (United States)

    Phuong Thu, Le; Michèle, Besson

    2016-06-01

    Sugarcane molasses distillery wastewater contains melanoidins, which are dark brown recalcitrant nitrogenous polymer compounds. Studies were carried out in batch mode to evaluate Pt and Ru supported catalysts in the Catalytic Wet Air Oxidation (CWAO) process of a synthetic melanoidins solution, prepared by stoichiometric reaction of glucose with glycine. The addition of a catalyst slightly improved TOC removal compared with the non-catalytic reaction, and especially promoted the conversion of ammonium produced from organically-bound nitrogen in melanoidins to molecular nitrogen and nitrate. The selectivity to N2 attained 89% in the presence of the Pt catalysts in the reaction conditions used (TOC=2200mgL(-1), TN=280mgL(-1), 0.5g catalyst loaded with 3% metal, 210°C, 70bar total air pressure). To avoid leaching of the active metal by organically-bound nitrogen, the reaction was very efficiently performed in a two-step reaction consisting in WAO to convert nitrogen into ammonium, before the introduction of a catalyst. PMID:26900982

  4. 催化湿式氧化预处理造纸黑液%Pretreatment of Black Liquor by Catalytic Wet Air Oxidation

    Institute of Scientific and Technical Information of China (English)

    董振海; 李利敏; 闫海生; 于姗姗; 李秀珍; 毕延文

    2011-01-01

    采用连续式固定床反应器,利用自制稀土类复合金属氧化物催化剂对草浆造纸黑液进行了催化湿式氧化(CWAO)预处理研究.通过正交实验确定了最佳工艺条件为:进水COD 40 800 mg/L,空速0.8h-1,反应温度260℃,反应压力6.5 MPa.在此最佳条件下进行实验,COD去除率达90%.经CWAO工艺处理后,草浆造纸黑液的可生化性显著提高,BOD5/COD由0.11提高至0.62.在1 000 h CWAO连续实验中,自制稀土类复合金属氧化物催化剂显示出较高催化活性和较好的稳定性.%The black liquor from straw pulp paper-making was pretreated by catalytic wet air oxidation (CWAO) in the continuous fixed bed reactor with self-made rare earth oxide catalyst. The optimum process conditions determined by the orthogonal tests are as follows: influent COD 40 800 mg/L,space velocity 0. 8 h-1 .reaction temperature 260℃, reaction pressure 6. 5 Mpa. Under these conditions, the COD removal rate is 90%. The biodegradability of the treated black liquor is significantly improved with BOD5/COD increased from 0. 11 to 0. 62. During 1 000 h of the CWAO continuous experiment, the catalytic activity and stability of the self-made rare earth oxide catalyst are good.

  5. Graphene-based materials in catalytic wet peroxide oxidation

    OpenAIRE

    Gomes, Helder; Ribeiro, Rui; Pastrana-Martínez, Luisa; Figueiredo, José; Faria, Joaquim; Silva, Adrián

    2014-01-01

    In catalytic wet peroxide oxidation (CWPO),an advanced oxidation process, hydrogen peroxide (H2O2) is decomposed catalytically giving rise to hydroxyl radicals (HO•).These radicals, exhibiting high oxidizing potential, serve as effective and non selective species for the degradation of several organic pollutants in liquid phase. Since the report of Lücking et al. [1], carbon materials have been explored as catalysts for CWPO[2]. Recent reports address process intensification issues, br...

  6. Nanostructured Catalytic Reactors for Air Purification Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  7. Nanostructured Catalytic Reactors for Air Purification Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase II project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  8. Research Progress on Catalyst of Catalytic Wet Air Oxidation for Phenol Wastewater%催化湿式氧化含酚废水催化剂的研究进展

    Institute of Scientific and Technical Information of China (English)

    李荣; 段大勇

    2015-01-01

    Catalytic wet air oxidation ( CWAO ) technology is an effective technology for phenol wastewater, developing and selecting suitable catalyst is a key factor of CWAO. Active components were briefly introduced and CWAO catalyst for phenol wastewater treatment was carried out. It was specified that selecting the best combination of suitable active component and carrier of CWAO catalyst can improve the efficiency of phenol degradation, developing the catalyst with high activity, stability and cheap characteristics was the development direction of CWAO for phenol wastewater treatment.%催化湿式氧化技术是处理含酚废水的有效技术,此技术的关键是合适催化剂的研制和选用。本文对催化湿式氧化含酚废水催化剂的活性组分、载体等情况进行了综述,并指出选用最佳活性组分和载体的组合能够提高催化剂对苯酚的降解效率,研发高活性、高稳定性及廉价的催化剂是催化湿式氧化含酚废水的发展方向。

  9. Process of forming catalytic surfaces for wet oxidation reactions

    Science.gov (United States)

    Jagow, R. B. (Inventor)

    1977-01-01

    A wet oxidation process was developed for oxidizing waste materials, comprising dissolved ruthenium salt in a reactant feed stream containing the waste materials. The feed stream is introduced into a reactor, and the reactor contents are then raised to an elevated temperature to effect deposition of a catalytic surface of ruthenium black on the interior walls of the reactor. The feed stream is then maintained in the reactor for a period of time sufficient to effect at least partial oxidation of the waste materials.

  10. Degradation of Bagasse Alkaline Lignin by Catalytic Wet Air Oxidation with Five Catalysts%催化剂对甘蔗渣碱木质素催化湿空气氧化降解的催化作用

    Institute of Scientific and Technical Information of China (English)

    姚向荣; 詹怀宇; 周生飞

    2011-01-01

    In this paper, bagasse alkaline lignin was degraded by Catalytic Wet Air Oxidation (CWAO) with five different catalysts. The results showed that the main degradation products were; p-hydroxybenzaldehyde, vanillin, syringaldehyde, syringic acid, vanillic acid and acetosyringone. The concentration of aromatic substances increased when the reaction time increased. Catalysts had a significant effect on the concentration of aromatic substances. Using CO2O3 as catalyst, the concentration of vanillin, syringaldehyde and acetosyringone were 400.2 mg/L, 351.4 mg/L, and 248.7 mg/L respectively, and the concentration of vanillin increased 82.6% comparing to no catalyst was used. Using AQ as catalyst, the concentration of vanillin was 344. 9 mg/L which was 1. 5 times of that without using catalyst. Using Co2O3, CuSO4, MnO2, AQ, Fe2O3 as catalysts, the total concentrations of phenolic aldehyde compounds were 1696 mg/L, 1658 mg/L, 1584 mg/ L, 1347 mg/L and 1250 mg/L respectively,which explained that using Co2O3 as the catalyst was the best, and CuSO4 and MnO2 were the next, the catalysts of AQ and Fe2O3 only contributed to produce several kinds of phenolic aldehyde compounds with small molecules.%选取5种不同的催化剂对甘蔗渣碱木质素进行了催化湿空气氧化降解。结果表明,甘蔗渣碱木质素催化湿空气氧化降解的主要产物为对羟基苯甲醛、香草醛、丁香醛、丁香酸、香草酸和乙酰丁香酮;在实验条件下,反应时间对催化剂催化效果的影响较大,随着反应时间的延长,大部分小分子酚醛类化合物的浓度逐渐升高;使用催化剂能较大幅度地提高小分子酚醛类化合物的浓度。以Co2O3为催化剂,丁香醛、乙酰丁香酮、香草醛的浓度分别为400.2 mg/L、351.4 mg/L 248.7 mg/L,与未添加催化剂相比较,香草醛浓度提高了 82.6%;当以AQ为催化剂时,香草醛浓度为344.9mg/L,与空白样相比其浓度提高了1.5倍以上。

  11. Study on Catalytic Wet Oxidation of H2S into Sulfur on Fe/Cu Catalyst

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A wet catalytic oxidation at room temperature was investigated with solution containing ferric, ferrous and cupric ions for H2S removal. The experiments were carried out in a two step process,and the results obtained show that the removal efficiency of H2S can always reach 100% in a 300 mm scrubbing column with four sieve plates, and the regeneration of ferric ions in 200 mm bubble column can match the consumed ferric species in absorption. Removal of H2S, production of elemental sulfur and regeneration of ferric, cupric ions can all be accomplished at the same time. No raw material is consumed except O2 in flue gas or air, the process has no secondary pollution and no problem of catalyst degradation and congestion.

  12. Advanced methods for the treatment of organic aqueous wastes: wet air oxidation and wet peroxide oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Debellefontaine, Hubert; Chakchouk, Mehrez; Foussard, Jean Noel [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France). Dept. de Genie des Procedes Industriels; Tissot, Daniel; Striolo, Phillipe [IDE Environnement S.A., Toulouse (France)

    1993-12-31

    There is a growing concern about the problems of wastes elimination. Various oxidation techniques are suited for elimination of organic aqueous wastes, however, because of the environmental drawbacks of incineration, liquid phase oxidation should be preferred. `Wet Air Oxidation` and `Wet Peroxide Oxidation`are alternative processes which are discussed in this paper. 17 refs., 13 figs., 4 tabs.

  13. HAZARDOUS AIR POLLUTANTS: WET REMOVAL RATES AND MECHANISMS

    Science.gov (United States)

    Fourteen hazardous organic air pollutants were evaluated for their potentials to be wet deposited by precipitation scavenging. This effort included a survey of solubilities (Henry's Law constants) in the literature, measurement of solubilities of three selected species, developme...

  14. Key parameters when developing carbonaceous materials for catalytic wet peroxide oxidation

    OpenAIRE

    Ribeiro, Rui; Silva, Adrián; Pastrana-Martínez, Luisa; Figueiredo, José; Faria, Joaquim; Gomes, Helder

    2014-01-01

    Catalytic wet peroxide oxidation (CWPO) is an advanced oxidation process, operated using simple equipment and mild operating conditians, in which highly oxidizing hydraxyl radicaIs (HO') are generated fram the catalytic decompasition af hydrogen peroxide (H,O,) [L 2). Sinee the report of Lüeking el ai. in 1998 [3], the develapment af suitab-Ie -carbonaceous materials (without any added metal phase) for CWPO has been intensively explored [4). lhe influenee of struetUfal and surr...

  15. Wet-air oxidation cleans up black wastewater

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    Sterling Organics produces the analgesic paracetamol (acetaminophen) at its Dudley, England, plant. The wastewater from the batch process contains intermediates such as para-aminophenol (PAP) and byproducts such as thiosulfates, sulfites and sulfides. To stay ahead of increasingly strict environmental legislation, Sterling Organics installed a wet-air oxidation system at the Dudley facility in August 1992. The system is made by Zimpro Environmental Inc. (Rothschild, Wis.). Zimpro's wet-air oxidation system finds a way around the limitations of purely chemical or physical processes. In the process, compressed air at elevated temperature and pressure oxidizes the process intermediates and byproducts and removes the color from the wastewater.

  16. The applicability of the catalytic wet-oxidation to CELSS

    Science.gov (United States)

    Takahashi, Y.; Nitta, K.; Ohya, H.; Oguchi, M.

    1987-01-01

    The wet oxidation catalysis of Au, Pd, Pt, Rh or Ru on a ceramic honeycomb carrier was traced in detail by 16 to 20 repetitive batch tests each. As a result, Pt or Pd on a honeycomb carrier was shown to catalyze complete nitrogen gasification as N2. Though the catalysts which realize both complete nitrogen gasification and complete oxidation could not be found, the Ru+Rh catalyst was found to be most promising. Ru honeycomb catalyzed both nitrification and nitrogen gasification.

  17. Orange II removal by catalytic wet peroxide oxidation using activated carbon xerogels

    OpenAIRE

    Pinho, Maria; Silva, Adrián; Fathy, Nady; Attia, Amina; Gomes, Helder; Faria, Joaquim

    2013-01-01

    Orange II is a synthetic dye widely employed in the textile industry and responsible for serious environrnentaI cancerns. Dyes like this urge the development af new technologies for the treatment af wastewaters generated in this industrial activity. Those include catalytic wet peroxide oxidation (CWPO), which is an advanced oxidation process (AOP) based on the generation of hydroxyl radicais (I-lO·) from hydrogen peroxide with tlle aid ofa suitable catalysl [I].

  18. Magnetic carbon xerogels for the catalytic wet peroxide oxidation of 4-nitrophenol solutions

    OpenAIRE

    Ribeiro, R; Silva, Adrián; Faria, Joaquim; Gomes, Helder

    2015-01-01

    Catalytic wet peroxide oxidation (CWPO) is a well-known advanced oxidation process for the removal of organic pollutants from industrial process waters and wastewater. Specifically, CWPO employs hydrogen peroxide (H2O2) as oxidation source and a suitable catalyst to promote its decomposition via formation of hydroxyl radicals (HO•), which exhibit high oxidizing potential and serve as effective species in the destruction of a huge range of organic pollutants

  19. Catalytic Converters Maintain Air Quality in Mines

    Science.gov (United States)

    2014-01-01

    At Langley Research Center, engineers developed a tin-oxide based washcoat to prevent oxygen buildup in carbon dioxide lasers used to detect wind shears. Airflow Catalyst Systems Inc. of Rochester, New York, licensed the technology and then adapted the washcoat for use as a catalytic converter to treat the exhaust from diesel mining equipment.

  20. Physical effects of negative air ions in a wet sauna

    Science.gov (United States)

    Watanabe, I.; Noro, Hiroshi; Ohtsuka, Yoshinori; Mano, Yukio; Agishi, Yuko

    The physical effects of negative air ions on humans were determined in an experimental sauna room equipped with an ionizer. Thirteen healthy persons took a wet sauna bath (dry bulb temperature 42° C, relative humidity 100%, 10 min exposure) with or without negative air ions. The subjects were not told when they were being exposed to negative air ions. There were no differences in the moods of these persons or changes in their blood pressures between the two saunas. The surface temperatures of the foreheads, hands, and legs in the sauna with negative ions were significantly higher than those in the sauna without ions. The pulse rates and sweat produced in the sauna with ions were singificantly higher than those in the sauna without ions. The results suggest that negative ions may amplify the effects on humans of the sauna.

  1. Spacecraft Water Regeneration by Catalytic Wet Air Oxidation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this project is to develop advanced catalysts for a volatile removal assembly used to purify spacecraft water. The innovation of the proposed...

  2. Catalytic wet peroxide oxidation of phenol solutions over CuO/CeO{sub 2} systems

    Energy Technology Data Exchange (ETDEWEB)

    Massa, Paola, E-mail: pamassa@fi.mdp.edu.ar [Division Catalizadores y Superficies, INTEMA, Universidad Nacional de Mar del Plata/CONICET, Juan B. Justo 4302, 7600 Mar del Plata, Buenos Aires (Argentina); Ivorra, Fernando; Haure, Patricia; Fenoglio, Rosa [Division Catalizadores y Superficies, INTEMA, Universidad Nacional de Mar del Plata/CONICET, Juan B. Justo 4302, 7600 Mar del Plata, Buenos Aires (Argentina)

    2011-06-15

    Three 5% CuO/CeO{sub 2} catalysts were synthesized by sol-gel, precipitation and combustion methods, followed by incipient wetness impregnation with copper nitrate. The samples were characterized by XRD, TPR, BET and tested for the catalytic wet peroxide oxidation of a phenol solution (5 g/L). The reaction took place in a batch reactor at atmospheric pressure, in a temperature range of 60-80{sup Degree-Sign }C , during 4 h. Phenol conversion, H{sub 2}O{sub 2} consumption, pH and chemical oxygen demand were determined. The reaction temperature and the catalyst loading did improve the phenol and the H{sub 2}O{sub 2} conversions. The effect on the selectivity towards complete mineralization was less marked, with levels among 60-70%. Stepwise addition of H{sub 2}O{sub 2} was also tested.

  3. Catalytic wet oxidation of thiocyanate with homogeneous copper(II) sulphate catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Collado, Sergio; Laca, Adriana [Department of Chemical Engineering and Environmental Technology, University of Oviedo, c/ Julian Claveria s/n, E-33071, Oviedo (Spain); Diaz, Mario, E-mail: mariodiaz@uniovi.es [Department of Chemical Engineering and Environmental Technology, University of Oviedo, c/ Julian Claveria s/n, E-33071, Oviedo (Spain)

    2010-05-15

    The wet oxidation of thiocyanate has been investigated in a semi-batch reactor at temperatures between 423 and 473 K and pressures between 6.1 x 10{sup 3} and 1.0 x 10{sup 4} kPa in the presence of copper(II) sulphate as catalyst. The effects of copper concentration, initial thiocyanate concentration, pressure and temperature on the reaction rate were analyzed and the main products of reaction were identified. A kinetic model for the Cu-catalyzed reaction is here proposed, including temperature, oxygen concentration, and the reduction of Cu{sup 2+} to Cu{sup +} that gives an accurate prediction of the oxidation process under the assayed conditions. A mechanistic model based on the formation of a transition complex between a copper cation and two thiocyanate anions has been proposed for the catalytic wet oxidation.

  4. Catalytic wet oxidation of thiocyanate with homogeneous copper(II) sulphate catalyst.

    Science.gov (United States)

    Collado, Sergio; Laca, Adriana; Díaz, Mario

    2010-05-15

    The wet oxidation of thiocyanate has been investigated in a semi-batch reactor at temperatures between 423 and 473 K and pressures between 6.1 x 10(3) and 1.0 x 10(4)kPa in the presence of copper(II) sulphate as catalyst. The effects of copper concentration, initial thiocyanate concentration, pressure and temperature on the reaction rate were analyzed and the main products of reaction were identified. A kinetic model for the Cu-catalyzed reaction is here proposed, including temperature, oxygen concentration, and the reduction of Cu(2+) to Cu(+) that gives an accurate prediction of the oxidation process under the assayed conditions. A mechanistic model based on the formation of a transition complex between a copper cation and two thiocyanate anions has been proposed for the catalytic wet oxidation.

  5. Wet air oxidation of seedcorn wastes containing pesticides and insecticides

    Energy Technology Data Exchange (ETDEWEB)

    Sievers, M.; Schlaefer, O.; Onyeche, T.I.; Schroeder, C.; Bormann, H.; Schaefer, S. [CUTEC-Inst. GmbH (Clausthal Environment Technology Inst.), Clausthal-Zellerfeld (Germany)

    2003-07-01

    Wet air oxidation as an alternative treatment process to pyrolysis and combustion of seedcorn wastes was investigated in lab-scale experiments. Due to solid condition of the seed corn waste, the process has been adapted by repeated spraying of water on the seed corn bulk to avoid the production of sludge and its subsequent dewatering. Original seed corns from industrial production plants were used for a degradation kinetic study under smooth wet air oxidation conditions. The temperatures were between 80 and 150 C, the pressure from 1 to 4.5 bar and the pH at different values from 3 to 13. Degradation rates for five different compounds of pesticides and insecticides, namely Imidacloprid, Thiram, Hymexazol, Carbofuran and Tefluthrin were conducted. These compounds represent the recently used in agricultural seedcorn applications. The degradation rate depends linearly on temperature between 80 and 150 C. At 120 C the lowest degradation rate was found for Tefluthrin by 25 mg/h per L reaction volume while the highest degradation rate to be conducted was for Imidacloprid at 363 mg/h L. (orig.)

  6. Kinetics of Wet Air Oxidation of Wastewater from Natural Fiber Web Desizing

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This work described the application of wet air oxidation (WAO) to the treatment of desizing wastewater from natural fiber processing. A two-liter autoclave batch reactor was used for the experiments. The range of operating temperature examined was between 150 and 290℃, and partial pressure of oxygen ranged from 0.375 to 2.25 MPa standardized at 25℃. Variations in Chemical Oxygen Demand(COD) and Total Organic Carbon(TOC) were monitored during each experiment and used to assess the performance of the process. Experimental results showed that WAO can be an efficient method for the treatment of desizing wnstewater. Furthermore, Catalytic Wet Air Oxidation (CWAO) was applied to reduce the reaction temperature and pressure in WAO process. A higher COD removal ratio was achieved under more mild reaction condition with the aid of CWAO. A mathematical model was also proposed to simulate the WAO process of desizing wastewater, in which three distinct kinetics steps were considered to describe the degradation of starch. The model simulations were in well agreement with the experimental data.

  7. Session 6: Water depollution from aniline and phenol by air oxidation and adsorptive-catalytic oxidation in liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Dobrynkin, N.M.; Batygina, M.V.; Noskov, A.S. [Boreskov Institute of Catalysis of Siberian Branch of Russian Academy of Sciences, Pr. Ak. Lavrentieva (Russian Federation)

    2004-07-01

    This paper is devoted to development of carbon catalysts and application of catalytic wet air oxidation for deep cleaning of polluted waters. The described catalysts and method are solving the problem of development environmentally reliable method for fluids treatment and allow carrying out the adsorption of pollutants on carbon CAPM (catalytically active porous material) with following regeneration of the CAPM without the loss of adsorptive qualities. The experiments have shown a principal capability simultaneously to use carbon CAPM as adsorbent and either as catalyst, or as a catalyst support for oxidation of aniline and phenol in water solutions. (authors)

  8. Leachate Treatment UsingWet Air Oxidation Processes

    Directory of Open Access Journals (Sweden)

    A Ebrahimi

    2011-04-01

    Full Text Available "nBackground and Objectives: Wet air oxidation (WAO is One of the advanced oxidation process which reduce organic matter concentration from industrial wastewater, toxic and non biodegradable substances and, solid waste leachate,etc. In this study the efficiency of wet air oxidation method in leachate treatment generating from Esfahan Composting factory was Evaluated."nMaterial and Methods: The experiment was carried out by adding 1.5 Lit of pretreated leachate sample the steel reactor with the volume of 3L. The reactor then underwent10 bar pressure at different temperature (100, 200 and 300 °C and various retention time (30, 60 and 90 min. Leachate sample in 18 stages from composting factory in Isfahan in the volume of 20 Lit was taken and the WAO method, was used for pre-treatments. Removal efficiency of COD, BOD, NH4-N, NO3 and TSS were examined."nResults: The results showed that the removal efficiency was more than 35% for COD, 38% for BOD, and 85% for TSS within one hour of reaction. The Maximum removal efficiency obtained in this study were 53.3% for NH4-N and 73.9 % forNO3-N."nConclusion: the results indicate that the reaction temperatures are the most important factors affecting degradation of organic matter. COD and BOD5 removal efficiency by WAO process increased as the time of reaction went up. In addition, BOD5/COD ratios of the effluents, which are generally regarded as an important index of biodegradability of leachate sample, were determined and improved grately as it reached to 84%. TheWAO process presented in this paper is considered an efficient process for pretreatment of leachate, as the COD, BOD5 and NO3 reduction observed in leachate samples.

  9. Low temperature catalytic combustion of natural gas - hydrogen - air mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Newson, E.; Roth, F. von; Hottinger, P.; Truong, T.B. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The low temperature catalytic combustion of natural gas - air mixtures would allow the development of no-NO{sub x} burners for heating and power applications. Using commercially available catalysts, the room temperature ignition of methane-propane-air mixtures has been shown in laboratory reactors with combustion efficiencies over 95% and maximum temperatures less than 700{sup o}C. After a 500 hour stability test, severe deactivation of both methane and propane oxidation functions was observed. In cooperation with industrial partners, scaleup to 3 kW is being investigated together with startup dynamics and catalyst stability. (author) 3 figs., 3 refs.

  10. USING WET AIR OXIDATION TECHNOLOGY TO DESTROY TETRAPHENYLBORATE

    Energy Technology Data Exchange (ETDEWEB)

    Adu-Wusu, K; Daniel McCabe, D; Bill Wilmarth, B

    2007-04-04

    A bench-scale feasibility study on the use of a Wet Air Oxidation (WAO) process to destroy a slurry laden with tetraphenylborate (TPB) compounds has been undertaken. WAO is an aqueous phase process in which soluble and/or insoluble waste constituents are oxidized using oxygen or oxygen in air at elevated temperatures and pressures ranging from 150 C and 1 MPa to 320 C and 22 MPa. The products of the reaction are CO{sub 2}, H{sub 2}O, and low molecular weight oxygenated organics (e.g. acetate, oxalate). Test results indicate WAO is a feasible process for destroying TPB, its primary daughter products [triphenylborane (3PB), diphenylborinic acid (2PB), and phenylboronic acid (1PB)], phenol, and most of the biphenyl byproduct. The required conditions are a temperature of 300 C, a reaction time of 3 hours, 1:1 feed slurry dilution with 2M NaOH solution, the addition of CuSO{sub 4}.5H{sub 2}O solution (500 mg/L Cu) as catalyst, and the addition of 2000 mL/L of antifoam. However, for the destruction of TPB, its daughter compounds (3PB, 2PB, and 1PB), and phenol without consideration for biphenyl destruction, less severe conditions (280 C and 1-hour reaction time with similar remaining above conditions) are adequate.

  11. Development of wet-proofed catalyst and catalytic exchange process for tritium extraction

    Energy Technology Data Exchange (ETDEWEB)

    Song, Myung Jae; Son, Soon Hwan; Chung, Yang Gun; Lee, Gab Bock [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

    1995-12-31

    To apply a liquid phase catalytic exchange(LPCE) process for the tritium extraction from tritiated heavy water, the wet proofed catalyst to allow the hydrogen isotopic exchange reaction between liquid water and hydrogen gas was developed. A styrene divinyl benzene copolymer was selected as am effective catalyst support and prepared by suspension copolymerization. After post-treatment, final catalyst supports were dipped in chloroplatinic acid solution. The catalyst support had a good physical properties at a particular preparation condition. The catalytic performance was successfully verified through hydrogen isotopic exchange reaction in the exchange column. A mathematical model for the tritium removal process consisted of LPCE front-ended process and cryogenic distillation process was established using the NTU-HTU method for LPCE column and the FUG method for cryogenic distillation column, respectively. A computer program was developed using the model and then used to investigate optimum design variables which affect the size of columns and tritium inventory (author). 84 refs., 113 figs.

  12. 14 CFR 119.53 - Wet leasing of aircraft and other arrangements for transportation by air.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Wet leasing of aircraft and other arrangements for transportation by air. 119.53 Section 119.53 Aeronautics and Space FEDERAL AVIATION... Chapter § 119.53 Wet leasing of aircraft and other arrangements for transportation by air. (a)...

  13. The study of leachate treatment by using three advanced oxidation process based wet air oxidation

    OpenAIRE

    Mokhtari Mehdi; Ebrahimi Asghar; Ehrampoush Mohammad Hassan; Karimi Behroz

    2013-01-01

    Abstract Wet air oxidation is regarded as appropriate options for wastewater treatment with average organic compounds. The general purpose of this research is to determine the efficiency of three wet air oxidation methods, wet oxidation with hydrogen peroxide and absorption with activated carbon in removing organic matter and nitrogenous compounds from Isfahan's urban leachate. A leachate sample with the volume of 1.5 liters entered into a steel reactor with the volume of three liters and was...

  14. The Study of LeachateTreatment by Using Three Advanced Oxidation Process Based Wet air Oxidation

    OpenAIRE

    Behroz Karimi; Mohammad Hassan Ehrampoush; Asghar Ebrahimi; Mehdi Mokhtari

    2013-01-01

    Wet air oxidation is regarded as appropriate options for wastewater treatment with average organic compounds. The general purpose of this research is to determine the efficiency of three wet air oxidation methods, wet oxidation with hydrogen peroxide and absorption with activated carbon in removing organic matter and nitrogenous compounds from Isfahan's urban leachate. A leachate sample with the volume of 1.5 liters entered into a steel reactor with the volume of three liters and was put unde...

  15. Treatment of hydraulic fracturing wastewater by wet air oxidation.

    Science.gov (United States)

    Wang, Wei; Yan, Xiuyi; Zhou, Jinghui; Ma, Jiuli

    2016-01-01

    Wastewater produced by hydraulic fracturing for oil and gas production is characterized by high salinity and high chemical oxygen demand (COD). We applied a combination of flocculation and wet air oxidation technology to optimize the reduction of COD in the treatment of hydraulic fracturing wastewater. The experiments used different values of flocculant, coagulant, and oxidizing agent added to the wastewater, as well as different reaction times and treatment temperatures. The use of flocculants for the pretreatment of fracturing wastewater was shown to improve treatment efficiency. The addition of 500 mg/L of polyaluminum chloride (PAC) and 20 mg/L of anionic polyacrylamide (APAM) during pretreatment resulted in a COD removal ratio of 8.2% and reduced the suspended solid concentration of fracturing wastewater to 150 mg/L. For a solution of pretreated fracturing wastewater with 12 mL of added H2O2, the COD was reduced to 104 mg/L when reacted at 300 °C for 75 min, and reduced to 127 mg/L when reacted at the same temperature for 45 min while using a 1 L autoclave. An optimal combination of these parameters produced treated wastewater that met the GB 8978-1996 'Integrated Wastewater Discharge Standard' level I emission standard. PMID:26942530

  16. Low-temperature catalytic gasification of wet industrial wastes. FY 1991--1992 interim report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.C.; Neuenschwander, G.G.; Hart, T.R.; Phelps, M.R.; Sealock, L.J. Jr.

    1993-07-01

    A catalytic gasification system operating in a pressurized water environment has been developed and refined at Pacific Northwest Laboratory (PNL) for over 12 years. Initial experiments were aimed at developing kinetics information for steam gasification of biomass in the presence of catalysts. The combined use of alkali and metal catalysts was reported for gasification of biomass and its components at low temperatures (350{degrees}C to 450{degrees}C). From the fundamental research evolved the concept of a pressurized, catalytic gasification system for converting wet biomass feedstocks to fuel gas. Extensive batch reactor testing and limited continuous reactor system (CRS) testing were undertaken in the development of this system under sponsorship of the US Department of Energy. A wide range of biomass feedstocks were tested, and the importance of the nickel metal catalyst was identified. Specific use of this process for treating food processing wastes was also studied. The concept application was further expanded to encompass cleanup of hazardous wastewater streams, and results were reported for batch reactor tests and continuous reactor tests. Ongoing work at PNL focuses on refining the catalyst and scaling the system to long-term industrial needs. The process is licensed as the Thermochemical Environmental Energy System (TEES{reg_sign}) to Onsite*Ofsite, Inc., of Duarte, California. This report is a follow-on to the 1989--90 interim report [Elliott et al. 1991], which reviewed the results of the studies conducted with a fixed-bed, continuous-feed, tubular reactor. The discussion here provides an overview of experiments on the wide range of potential feedstock materials conducted in a batch reactor; development of new catalyst materials; and tests performed in continuous-flow reactors at three scales. The appendices contain the history and background of the process development, as well as more detailed descriptions and results of the recent studies.

  17. Catalytic wet peroxidation of pyridine bearing wastewater by cerium supported SBA-15

    Energy Technology Data Exchange (ETDEWEB)

    Subbaramaiah, V. [Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand (India); Srivastava, Vimal Chandra, E-mail: vimalcsr@yahoo.co.in [Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand (India); Mall, Indra Deo [Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand (India)

    2013-03-15

    Highlights: ► Cerium supported SBA-15 (Ce/SBA-15) synthesized by two-step synthesis. ► Characterization of Ce/SBA-15 by FTIR, XRD and BET surface area. ► Catalytic peroxidation of pyridine by Ce/SBA-15. ► Optimization of parameters like catalyst dose, H{sub 2}O{sub 2} dose, initial concentration and temperature. ► Catalyst reusability and leaching study performed. -- Abstract: Cerium supported SBA-15 (Ce/SBA-15) was synthesized by two-step synthesis method in acidic medium. It was further characterized by various characterization techniques such as X-ray diffraction, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy and N{sub 2} adsorption–desorption pore size distribution analysis. The Ce/SBA-15 showed highly ordered meso-structure with pore diameter ≈ 70–100 A and pore volume ≈ 0.025 cm{sup 3}/g. Ce/SBA-15 was further evaluated as a catalyst for the oxidation of highly toxic and non-biodegradable material, pyridine, by catalytic wet-peroxidation method. The effects of various operating parameters such as catalyst dose (0.5–6 g/l), stoichiometric ratio of H{sub 2}O{sub 2}/pyridine (1–6), initial pyridine concentration (50–800 mg/l) and temperature (313–358 K) have been evaluated and optimized. Ce/SBA-15 showed stable performance during reuse for six cycles with negligible cerium leaching. Kinetic and thermodynamic parameters and operation cost have also been determined.

  18. Chloride ions promoted the catalytic wet peroxide oxidation of phenol over clay-based catalysts.

    Science.gov (United States)

    Zhou, Shiwei; Zhang, Changbo; Xu, Rui; Gu, Chuantao; Song, Zhengguo; Xu, Minggang

    2016-01-01

    Catalytic wet peroxide oxidation (CWPO) of phenol over clay-based catalysts in the presence and absence of NaCl was investigated. Changes in the H2O2, Cl(-), and dissolved metal ion concentration, as well as solution pH during phenol oxidation, were also studied. Additionally, the intermediates formed during phenol oxidation were detected by liquid chromatography-mass spectroscopy and the chemical bonding information of the catalyst surfaces was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the presence of Cl(-) increased the oxidation rate of phenol to 155%, and this phenomenon was ubiquitous during the oxidation of phenolic compounds by H2O2 over clay-based catalysts. Cl(-)-assisted oxidation of phenol was evidenced by several analytical techniques such as mass spectroscopy (MS) and XPS, and it was hypothesized that the rate-limiting step was accelerated in the presence of Cl(-). Based on the results of this study, the CWPO technology appears to be promising for applications in actual saline phenolic wastewater treatment. PMID:26942523

  19. Catalytic wet oxidation of the pretreated synthetic pulp and paper mill effluent under moderate conditions.

    Science.gov (United States)

    Garg, Anurag; Mishra, I M; Chand, Shri

    2007-01-01

    In the present study, catalytic wet oxidation (CWO) was investigated for the destruction of organic pollutants in the thermally pretreated effluent from a pulp and paper mill under moderate temperature and pressure conditions. The thermal pretreatment studies were conducted at atmospheric pressure and 368K using copper sulfate as a catalyst. The thermal pretreatment reduced COD by about 61%. The filtrate of the thermal pretreatment step was used at pH 8.0 for CWO at 383-443K temperature and a total pressure of 0.85MPa for 4h. Catalysts used for the reaction include copper sulfate, 5% CuO/95% activated carbon, 60% CuO/40% MnO(2), and 60% CuO/40% CeO(2). Maximum COD reduction was found to be 89% during CWO step using 5% CuO/95% activated carbon with a catalyst loading of 8gl(-1) at 443K and 0.85MPa total pressure. Overall COD reduction for the pretreatment and the CWO was found to be 96%. Besides this, 60% CuO/40% CeO(2) catalyst also exhibited the similar activity as that of obtained with 5% CuO/95% activated carbon catalyst at 423K temperature and 0.85MPa total pressure. The pH of the solution during the experimental runs decreases initially due to the formation of carboxylic acid and then increases due to the decomposition of acids. PMID:16934854

  20. Catalytic oxidation with Al-Ce-Fe-PILC as a post-treatment system for coffee wet processing wastewater.

    Science.gov (United States)

    Sanabria, Nancy R; Peralta, Yury M; Montañez, Mardelly K; Rodríguez-Valencia, Nelson; Molina, Rafael; Moreno, Sonia

    2012-01-01

    The effluent from the anaerobic biological treatment of coffee wet processing wastewater (CWPW) contains a non-biodegradable compound that must be treated before it is discharged into a water source. In this paper, the wet hydrogen peroxide catalytic oxidation (WHPCO) process using Al-Ce-Fe-PILC catalysts was researched as a post-treatment system for CWPW and tested in a semi-batch reactor at atmospheric pressure and 25 °C. The Al-Ce-Fe-PILC achieved a high conversion rate of total phenolic compounds (70%) and mineralization to CO(2) (50%) after 5 h reaction time. The chemical oxygen demand (COD) of coffee processing wastewater after wet hydrogen peroxide catalytic oxidation was reduced in 66%. The combination of the two treatment methods, biological (developed by Cenicafé) and catalytic oxidation with Al-Ce-Fe-PILC, achieved a 97% reduction of COD in CWPW. Therefore, the WHPCO using Al-Ce-Fe-PILC catalysts is a viable alternative for the post-treatment of coffee processing wastewater. PMID:22907449

  1. PERFORMANCE OF ACTIVATED SLUDGE-POWDERED ACTIVATED CARBON-WET AIR REGENERATION SYSTEMS

    Science.gov (United States)

    The investigation summarized in the report was undertaken to evaluate the performance of powdered activated carbon (PAC) technology used in conjunction with wet air regeneration (WAR) at municipal wastewater treatment plants. Excessive ash concentrations accumulated in the mixed ...

  2. Unprecedented Catalytic Wet Oxidation of Glucose to Succinic Acid Induced by the Addition of n-Butylamine to a Ru(III) Catalyst.

    Science.gov (United States)

    Podolean, Iunia; Rizescu, Cristina; Bala, Camelia; Rotariu, Lucian; Parvulescu, Vasile I; Coman, Simona M; Garcia, Hermenegildo

    2016-09-01

    A new pathway for the catalytic wet oxidation (CWO) of glucose is described. Employing a cationic Ru@MNP catalyst, succinic acid is obtained in unprecedently high yield (87.5 %) for a >99.9 % conversion of glucose, most probably through a free radical mechanism combined with catalytic didehydroxylation of vicinal diols and hydrogenation of the resulted unsaturated intermediate. PMID:27511900

  3. Repeated bouncing of drops on wetting and non-wetting surfaces mediated by a persisting thin air film

    Science.gov (United States)

    de Ruiter, Jolet; Lagraauw, Rudy; van den Ende, Dirk; Mugele, Frieder

    2014-11-01

    Liquid drops impinging onto solid surfaces undergo a variety of impact scenarios such as splashing, sticking, and bouncing, depending on impact conditions and substrate properties. Bouncing requires efficient conversion of initial kinetic energy into surface energy and back into kinetic energy. This process is believed to be limited to non-wetting, in particular superhydrophobic surfaces, for which viscous dissipation during drop-substrate contact is minimal. Here, we report a novel bouncing mechanism that applies equally to non-wetting and wetting systems for flat surfaces with contact angles down to 10 degrees. For initial impact speeds up to about 0.5 m/s we demonstrate using dual wavelength interferometry that aqueous and non-aqueous drops remain separated from the substrate by air films of (sub)micrometer thickness at all times throughout a series of up to 16 consecutive bouncing events. We show that the purely dissipative force arising from the viscous squeeze-out of air is responsible for both the momentum transfer and for a substantial part of the residual energy dissipation.

  4. A compact process for the treatment of olive mill wastewater by combining wet hydrogen peroxide catalytic oxidation and biological techniques

    Energy Technology Data Exchange (ETDEWEB)

    Azabou, Samia [Laboratoire des BioProcedes, Centre de Biotechnologie de Sfax, BP 1177, 3018 Sfax (Tunisia); Najjar, Wahiba [Laboratoire de Chimie des Materiaux et Catalyse, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunis (Tunisia); Bouaziz, Mohamed [Laboratoire des BioProcedes, Centre de Biotechnologie de Sfax, BP 1177, 3018 Sfax (Tunisia); Ghorbel, Abdelhamid [Laboratoire de Chimie des Materiaux et Catalyse, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunis (Tunisia); Sayadi, Sami, E-mail: sami.sayadi@cbs.rnrt.tn [Laboratoire des BioProcedes, Centre de Biotechnologie de Sfax, BP 1177, 3018 Sfax (Tunisia)

    2010-11-15

    A system based on combined actions of catalytic wet oxidation and microbial technologies for the treatment of highly polluted OMW containing polyphenols was studied. The wet hydrogen peroxide catalytic oxidation (WHPCO) process has been investigated in the semi-batch mode at atmospheric pressure, using aluminium-iron-pillared inter layer clay ((Al-Fe)PILC), under two different catalytic processes: ((Al-Fe)PILC/H{sub 2}O{sub 2}/ultraviolet radiations) at 25 deg. C and ((Al-Fe)PILC/H{sub 2}O{sub 2}) at 50 deg. C. The results show that raw OMW was resistant to the photocatalytic process. However ((Al-Fe)PILC/H{sub 2}O{sub 2}), system operating at 50 deg. C reduced considerably the COD, colour and total phenolic contents, and thus decreased the inhibition of the marine photobacteria Vibrio fischeri luminescence by 70%. This study also examined the feasibility of coupling WHPCO and anaerobic digestion treatment. Biomethanisation experiments performed with raw OMW or pre-treated OMW proved that pre-treatments with ((Al-Fe)PILC/H{sub 2}O{sub 2}) system, for more than 2 h, resulted in higher methane production. Both untreated OMW as well as 2-h pre-treated OMW revealed as toxic to anaerobic bacteria.

  5. A compact process for the treatment of olive mill wastewater by combining wet hydrogen peroxide catalytic oxidation and biological techniques

    International Nuclear Information System (INIS)

    A system based on combined actions of catalytic wet oxidation and microbial technologies for the treatment of highly polluted OMW containing polyphenols was studied. The wet hydrogen peroxide catalytic oxidation (WHPCO) process has been investigated in the semi-batch mode at atmospheric pressure, using aluminium-iron-pillared inter layer clay ((Al-Fe)PILC), under two different catalytic processes: ((Al-Fe)PILC/H2O2/ultraviolet radiations) at 25 deg. C and ((Al-Fe)PILC/H2O2) at 50 deg. C. The results show that raw OMW was resistant to the photocatalytic process. However ((Al-Fe)PILC/H2O2), system operating at 50 deg. C reduced considerably the COD, colour and total phenolic contents, and thus decreased the inhibition of the marine photobacteria Vibrio fischeri luminescence by 70%. This study also examined the feasibility of coupling WHPCO and anaerobic digestion treatment. Biomethanisation experiments performed with raw OMW or pre-treated OMW proved that pre-treatments with ((Al-Fe)PILC/H2O2) system, for more than 2 h, resulted in higher methane production. Both untreated OMW as well as 2-h pre-treated OMW revealed as toxic to anaerobic bacteria.

  6. Analysis of a wet scrubber network in the air remediation of industrial workplaces: benefit for the city air quality

    OpenAIRE

    Avveduto, Alessandro; Salisburgo, Cesare Dari; Pace, Lorenzo; Curci, Gabriele; Monaco, Alessio; De Giovanni, Marina; Giammaria, Franco; SPANTO, Giuseppe; Tripodi, Paolo

    2015-01-01

    Industrial activities carried out in confined spaces are characterized by a very specific type of air pollution. The extended exposure to this kind of pollution is often highly harmful, resulting in dramatic effects both on health and safety aspects. The indoor industrial abatement systems, adopted to purify the air, are typically applied to the emission points. The processed air is subsequently emitted outside. In this study we present the experimental results of three-stage wet scrubber sys...

  7. A kinetic model of municipal sludge degradation during non-catalytic wet oxidation.

    Science.gov (United States)

    Prince-Pike, Arrian; Wilson, David I; Baroutian, Saeid; Andrews, John; Gapes, Daniel J

    2015-12-15

    Wet oxidation is a successful process for the treatment of municipal sludge. In addition, the resulting effluent from wet oxidation is a useful carbon source for subsequent biological nutrient removal processes in wastewater treatment. Owing to limitations with current kinetic models, this study produced a kinetic model which predicts the concentrations of key intermediate components during wet oxidation. The model was regressed from lab-scale experiments and then subsequently validated using data from a wet oxidation pilot plant. The model was shown to be accurate in predicting the concentrations of each component, and produced good results when applied to a plant 500 times larger in size. A statistical study was undertaken to investigate the validity of the regressed model parameters. Finally the usefulness of the model was demonstrated by suggesting optimum operating conditions such that volatile fatty acids were maximised. PMID:26426294

  8. About sorption-catalytic air cleaning in premises for people habitation in megapolises

    Directory of Open Access Journals (Sweden)

    A.V. Cрechevichkin

    2011-01-01

    Full Text Available The basic sources of pollution of the air environment in megapolises, and also of internal atmosphere of premises for people habitation, in respect of their possible clearing by sorption-catalytic methods are systematized. Design and principle of action of the room sorption-catalytic three-chambered filter for clearing of turnaround air of a thermo premise of gaseous ammonia, hydrogen sulfide, carbon dioxide and organic substances are described.

  9. Combination of coagulation and catalytic wet oxidation for the treatment of pulp and paper mill effluents.

    Science.gov (United States)

    Verenich; Laari, A; Nissen, M; Kallas, J

    2001-01-01

    Wet oxidation (WO) is a well established process for purification of concentrated municipal and industrial wastewaters. Many attempts have been made to modify the WO process or to create a suitable combination of processes. This work was undertaken to investigate wet oxidation integrated with coagulation, i.e. to treat the sludge remaining after coagulation with a WO process. The possibility of regeneration of the used coagulant was also considered. Two waters from paper mills were used: TMP (thermomechanical pulp) circulation water and membrane concentrate. About 50% of the COD in the original water can be removed by coagulation using Fe2(SO4)3. The results from the wet oxidation experiments show the positive effect of iron in the chemical sludge as a catalyst. The efficiency of the WO process was enhanced almost by 100%. The remaining dissolved organic matter can be easily removed biologically. PMID:11695452

  10. 40 CFR 424.40 - Applicability; description of the covered calcium carbide furnaces with wet air pollution control...

    Science.gov (United States)

    2010-07-01

    ... covered calcium carbide furnaces with wet air pollution control devices subcategory. 424.40 Section 424.40... FERROALLOY MANUFACTURING POINT SOURCE CATEGORY Covered Calcium Carbide Furnaces With Wet Air Pollution Control Devices Subcategory § 424.40 Applicability; description of the covered calcium carbide...

  11. Removal of Xylene fromWaste Air Stream Using Catalytic Ozonation Process

    Directory of Open Access Journals (Sweden)

    H Mokarami

    2010-10-01

    Full Text Available "n "n "nBackgrounds and Objectives: Volatile organic compounds (VOCs are one of the common groups of contaminants encountered in the industrial activities, emitted through air stream into the atmosphere. To prevent the human and environmental health from the adverse effects of VOCs, air streams containing VOCs need to be treated before discharging to environment. This study was aimed at investigating the catalytic ozonation process for removing xylene from a contaminated air stream."nMaterials and Methods: In the present work, a bench scale experimental setup was constructed and used for catalytic ozonation of xylene. The performance of catalytic ozonation process was compared with that of single adsorption and ozonation in removal of several concentration of xylene under the similar experimental conditions."nResults: The results indicated that the efficiency of catalytic ozonation was higher than that of single adsorption and ozonation in removal of xylene. The emerging time and elimination capacity of xylene for inlet concentration of 300 ppm was 1.4 and 5.8 times of those in adsorption system. The activated carbon acted as catalyst in the presence of ozone and thus attaining the synergistic effect for xylene degradation."nConclusion: catalytic ozonation process is an efficient technique the treatment of air streams containing high concentrations of xylene. The adsorption systems can also be simply retrofitted to catalytic ozonation process and thereby improving their performance for treating VOCs.

  12. Sulfate Attack Resistance of Air-entrained Silica Fume Concrete under Dry-Wet Cycle Condition

    Institute of Scientific and Technical Information of China (English)

    YANG Jiansen; WANG Peiming; LI Haoxin; YANG Xu

    2016-01-01

    Based on the erosion resistant coefficient, the effects of water-cement ratio, air-entrained, silica fume content and sand ratio on the sulfate attack resistance of air-entrained silica fume concrete were studied by orthogonal experiments in order to explore its sulfate attack resistance under dry-wet condition. A more signiifcant model of concrete resistance to sulfate attack was also established, thus this work provided a strategy reference for quantitative design of sulfate attack resistant concrete. The experimental results show that dry-wet cycle deteriorates the concrete resistance to the sulfate attack, and leads to the remarkable declines of concrete strength and sulfate resistance. Air bubbles in the air-entrained silica fume concrete lower and delay the damage resulted from the crystallization sulfate salt. However this delay gradually disappears when most of the close bubbles are breached by the alternative running of the sulfate salt crystallization and the permeating pressure, and then the air bubbles are iflled with sulfate salt crystallization. The concrete is provided with the strongest sulfate resistance when it is prepared with the 0.47 water-binder ratio, 6.0% air-entrained, 5% silica fume and 30% sand ratio. The erosion resistant coefifcientsK80 andK150 of this concrete are increased by 9%, 7%, 9%, and 5% respectively as compared with those of concretes without silica fume and air entraining.

  13. Modifications of oxidized Zircaloy-4 surface in contact with radiolysed wet air

    Energy Technology Data Exchange (ETDEWEB)

    Guipponi, C. [Universite de Lyon, Institut de Physique Nucleaire de Lyon, Universite Claude Bernard Lyon 1, CNRS UMR5822, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Millard-Pinard, N., E-mail: millard@ipnl.in2p3.fr [Universite de Lyon, Institut de Physique Nucleaire de Lyon, Universite Claude Bernard Lyon 1, CNRS UMR5822, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Bererd, N. [Universite de Lyon, Institut de Physique Nucleaire de Lyon, Universite Claude Bernard Lyon 1, CNRS UMR5822, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Universite de Lyon, UCBL-IUT Lyon 1, departement chimie, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne Cedex (France); Serris, E.; Pijolat, M.; Peres, V. [Ecole Nationale Superieure des Mines de Saint Etienne, Centre SPIN, CNRS UMR5148, 158 cours Fauriel, 42 033 Saint Etienne Cedex (France); Wasselin-Trupin, V. [Institut de Radioprotection et de Surete Nucleaire, BP. 17, 92 262 Fontenay aux Roses (France)

    2012-02-01

    In the framework of radioactive waste geological disposal, the long term evolution of the nuclear wastes packages and the release of the radionuclides from the wastes have to be studied. Regarding compacted wastes (cladding tubes) coming from reprocessing of spent fuel, the Zircaloy-4 (zirconium alloy) cladding tubes have been activated and oxidized in reactors. In the disposal, the radioactive waste is exposed to humid air in a first phase and to water after the resaturation phase. In order to better assess the degradation process of these nuclear waste package, the influence of wet air proton radiolysis on the behavior of surface oxidized Zircaloy-4 has been investigated. Radiolysis experiments were performed using an irradiation cell which is associated to an extracted beam. Samples are exposed to wet air, under and without radiolysis, during 12 and 24 h. The water partial pressure has been fixed at 6 and 50 mbar in order to have, respectively, localized adsorbed water molecules and a thin film of adsorbed water. Before and after each treatment, sample surfaces were characterized by X-ray Photoelectron Spectroscopy (XPS) in order to identify the elements at the topmost surface of the solid. The wet air radiolysis causes changes at the surface of oxidized Zircaloy-4 and influences the corrosion phenomenon. Indeed, an enrichment of tin and the presence of nitrogen species were observed. It could be due to the formation of tritin(II) tetrahydroxide dinitrate and a Zr{sup 4+} tetramer on the topmost oxide surface.

  14. Treatment of desizing wastewater from the textile industry by wet air oxidation

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper describes the application of wet air oxidation to the treatment of desizing wastewater from two textile companies. A two-liter high temperature, high pressure autoclave reactor was used in the study. The range of operating temperatures examined was between 150 and 290℃, and the partial pressure of oxygen ranged from 0. 375 to 2.25 MPa. Variations in pH,CODCr and TOD content were monitored during each experiment and used to assess the extent of conversion of the process. The effects of temperature, pressure and reaction time were explored extensively. More than 90 % CODCr reduction and 80 % TOC removal have been obtained. The results have also been demonstrated that WAO is a suitable pre-treatment methods due to improvement of the BOD5/CODCr ratio of desizing wastewater. The reaction kinetics of wet air oxidation of desizing wastewater has been proved to be two steps, a fast reaction followed by a slow reaction stage.

  15. Catalytic wet peroxide oxidation of aniline in wastewater using copper modified SBA-15 as catalyst.

    Science.gov (United States)

    Kong, Liming; Zhou, Xiang; Yao, Yuan; Jian, Panming; Diao, Guowang

    2016-01-01

    SBA-15 mesoporous molecular sieves modified with copper (Cu-SBA-15) were prepared by pH-adjusting hydrothermal method and characterized by X-ray diffraction, BET, transmission electron microscopy, UV-Vis and (29)Si MAS NMR. The pH of the synthesis gel has a significant effect on the amount and the dispersion of copper on SBA-15. The Cu-SBA-15(4.5) (where 4.5 denotes the pH value of the synthesis gel) modified with highly dispersed copper was used as catalyst for the oxidation of aniline by H2O2. The Cu-SBA-15(4.5) shows a higher catalytic activity compared to CuO on the surface of SBA-15. The influences of reaction conditions, such as initial pH of the aqueous solutions, temperature, as well as the dosages of H2O2 and catalyst were investigated. Under weakly alkaline aqueous solution conditions, the aniline conversion, the H2O2 decomposition and the total organic carbon (TOC) removal could be increased significantly compared to the acid conditions. The percentage of leaching Cu(2+) could be decreased from 45.0% to 3.66% when the initial pH of solution was increased from 5 to 10. The TOC removal could be enhanced with the increases of temperature, H2O2 and catalyst dosage, but the aniline conversion and H2O2 decomposition change slightly with further increasing dosage of catalyst and H2O2. At 343 K and pH 8.0, 100% aniline conversion and 66.9% TOC removal can be achieved under the conditions of 1.0 g/L catalyst and 0.05 mol/L H2O2 after 180 min. Although copper might be slightly leached from catalyst, the homogeneous Cu(2+) contribution to the whole catalytic activity is unimportant, and the highly dispersed copper on SBA-15 plays a dominant role. PMID:26227827

  16. Catalytic wet peroxide oxidation of aniline in wastewater using copper modified SBA-15 as catalyst.

    Science.gov (United States)

    Kong, Liming; Zhou, Xiang; Yao, Yuan; Jian, Panming; Diao, Guowang

    2016-01-01

    SBA-15 mesoporous molecular sieves modified with copper (Cu-SBA-15) were prepared by pH-adjusting hydrothermal method and characterized by X-ray diffraction, BET, transmission electron microscopy, UV-Vis and (29)Si MAS NMR. The pH of the synthesis gel has a significant effect on the amount and the dispersion of copper on SBA-15. The Cu-SBA-15(4.5) (where 4.5 denotes the pH value of the synthesis gel) modified with highly dispersed copper was used as catalyst for the oxidation of aniline by H2O2. The Cu-SBA-15(4.5) shows a higher catalytic activity compared to CuO on the surface of SBA-15. The influences of reaction conditions, such as initial pH of the aqueous solutions, temperature, as well as the dosages of H2O2 and catalyst were investigated. Under weakly alkaline aqueous solution conditions, the aniline conversion, the H2O2 decomposition and the total organic carbon (TOC) removal could be increased significantly compared to the acid conditions. The percentage of leaching Cu(2+) could be decreased from 45.0% to 3.66% when the initial pH of solution was increased from 5 to 10. The TOC removal could be enhanced with the increases of temperature, H2O2 and catalyst dosage, but the aniline conversion and H2O2 decomposition change slightly with further increasing dosage of catalyst and H2O2. At 343 K and pH 8.0, 100% aniline conversion and 66.9% TOC removal can be achieved under the conditions of 1.0 g/L catalyst and 0.05 mol/L H2O2 after 180 min. Although copper might be slightly leached from catalyst, the homogeneous Cu(2+) contribution to the whole catalytic activity is unimportant, and the highly dispersed copper on SBA-15 plays a dominant role.

  17. Development of the Monolith Froth Reactor for Catalytic Wet Oxidation of CELSS Model Wastes

    Science.gov (United States)

    Abraham, Martin; Fisher, John W.

    1995-01-01

    The aqueous phase oxidation of acetic acid, used as a model compound for the treatment of CELSS (Controlled Ecological Life Support System) waste, was carried out in the monolith froth reactor which utilizes two-phase flow in the monolith channels. The catalytic oxidation of acetic acid was carried out over a Pt/Al2O3 catalyst, prepared at The University of Tulsa, at temperatures and pressures below the critical point of water. The effect of externally controllable parameters (temperature, liquid flow rate, distributor plate orifice size, pitch, and catalyst distance from the distributor plate) on the rate of acetic acid oxidation was investigated. Results indicate reaction rate increased with increasing temperature and exhibited a maximum with respect to liquid flow rate. The apparent activation energy calculated from reaction rate data was 99.7 kJ/mol. This value is similar to values reported for the oxidation of acetic acid in other systems and is comparable to intrinsic values calculated for oxidation reactions. The kinetic data were modeled using simple power law kinetics. The effect of "froth" feed system characteristics was also investigated. Results indicate that the reaction rate exhibits a maximum with respect to distributor plate orifice size, pitch, and catalyst distance from the distributor plate. Fundamental results obtained were used to extrapolate where the complete removal of acetic acid would be obtained and for the design and operation of a full scale CELSS treatment system.

  18. Low-temperature catalytic gasification of wet industrial wastes. FY 1993--1994 interim report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.C.; Hart, T.R.; Neuenschwander, G.G.; Deverman, G.S.; Werpy, T.A.; Phelps, M.R.; Baker, E.G.; Sealock, L.J. Jr.

    1995-03-01

    Process development research is continuing on a low-temperature, catalytic gasification system that has been demonstrated to convert organics in water (dilute or concentrated) to useful and environmentally safe gases. The system, licensed under the trade name Thermochemical Environmental Energy System (TEESO), treats a wide variety of feedstocks ranging from hazardous organics in water to waste sludges from food processing. The current research program is focused on the use of continuous-feed, tubular reactors systems for testing catalysts and feedstocks in the process. A range of catalysts have been tested, including nickel and other base metals, as well as ruthenium and other precious metals. Results of extensive testing show that feedstocks, ranging from 2% para-cresol in water to potato waste and spent grain, can be processed to > 99% reduction of chemical oxygen demand (COD). The product fuel gas contains from 40% up to 75% methane, depending on the feedstock. The balance of the gas is mostly carbon dioxide with < 5% hydrogen and usually < 1% ethane and higher hydrocarbons. The byproduct water stream carries residual organics from 10 to 1,000 mg/l COD, depending on the feedstock. The level of development of TEES has progressed to the initial phases of industrial process demonstration. Testing of industrial waste streams is under way at both the bench scale and engineering scale of development.

  19. Wet deposition of air pollution at southwest monsoon outbreak and its impact on groundwater resources of Greater Kochi region

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, T.; Nair, M.; Balachandran, K.K.; Nair, K.K.C.

    The replenishable groundwater resources from natural recharge for Greater Kochi Region (GKR) is of low quantity and it suffer from salinity intrusion, with the level of ground water development at 21.02%. The wet deposition of air pollution...

  20. Resting Study of Tracer Experiment on Catalytic Wet Oxidation Reactor under Micro-gravity and Earth Gravity Conditions

    Institute of Scientific and Technical Information of China (English)

    YANG Ji; JIA Jin-ping

    2005-01-01

    The International Space Station(ISS) employs catalytic wet oxidation carried out in a Volatile Reactor Assembly (VRA) for water recycling. Previous earth gravity experiments show that the VRA is very effective at removing polar,low molecular weight organics. To compare the reactor performance under micro-gravity and Earth gravity conditions,a tracer study was performed on a space shuttle in 1999 by using 0. 2% potassium carbonate as the chemical tracer.In this paper, the experimental data were analyzed and it is indicated that the reactor can be considered as a plug flow one under both micro-gravity and earth gravity experimental conditions. It has also been proved that dispersion is not important in the VRA reactor under the experimental conditions. Tracer retardation was observed in the experiments and it is most likely caused by catalyst adsorption. It is concluded that the following reasons may also have influence on the retardation of mean residence time: (1) the liquid can be held by appurtenances, which will retard the mean residence time; (2) the pores can hold the tracer, which can also retard the mean residence time.

  1. CATALYTIC WET PEROXIDE OXIDATION OF HYDROQUINONE WITH Co(Ⅱ)/ACTIVE CARBON CATALYST LOADED IN STATIC BED

    Institute of Scientific and Technical Information of China (English)

    LI Chunxiang; YAN Yongsheng; XU Wanzhen

    2008-01-01

    Catalysts based on Co(Ⅱ) supported on active carbon were prepared and loaded in static bed.The hydroquinone wouid be degraded completely after treated by Catalytic wet peroxide oxidation method with Co(Ⅱ)/active carbon catalyst.After activate treatment, the active carbon was immerged in cobaltoas nitrate solution, then put into a drying oven, Co(Ⅱ) could be loaded on the micro-surface of carbon.Taking the static bed as the equipment, the absorption of active carbon and catalysis of Co(Ⅱ) was used to reduce activation energy of hydroquinone.Thus hydroquinone could be drastically degraded and the effluent can be drained under the standard.Referring to Fenton reaction mechanism, experiment had been done to study the heterogeneous catalyzed oxidation mechanism of Co(Ⅱ).The degradation rate of hydroquinone effluent could be achieved to 92% when treated in four columns at H2O2 concentration 10%, reaction temperature 40℃, pH 5 and reaction time 2.5h.

  2. CATALYTIC WET PEROXIDE OXIDATION OF HYDROQUINONE WITH Co(II)/ACTIVE CARBON CATALYST LOADED IN STATIC BED

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Catalysts based on Co(II) supported on active carbon were prepared and loaded in static bed. The hydroquinone would be degraded completely after treated by Catalytic wet peroxide oxidation method with Co(II)/active carbon catalyst. After activate treatment, the active carbon was immerged in cobaltous nitrate solution, then put into a drying oven, Co(II) could be loaded on the micro-surface of carbon. Taking the static bed as the equipment, the absorption of active carbon and catalysis of Co(II) was used to reduce activation energy of hydroquinone. Thus hydroquinone could be drastically degraded and the effluent can be drained under the standard. Referring to Fenton reaction mechanism, experiment had been done to study the heterogeneous catalyzed oxidation mechanism of Co(II). The degradation rate of hydroquinone effluent could be achieved to 92% when treated in four columns at H2O2 concentration 10%, reaction temperature 40℃ , pH 5 and reaction time 2.5h.

  3. Analysis of a wet scrubber network in the air remediation of industrial workplaces: benefit for the city air quality

    CERN Document Server

    Avveduto, Alessandro; Pace, Lorenzo; Curci, Gabriele; Monaco, Alessio; De Giovanni, Marina; Giammaria, Franco; Spanto, Giuseppe; Tripodi, Paolo

    2015-01-01

    Industrial activities carried out in confined spaces are characterized by a very specific type of air pollution. The extended exposure to this kind of pollution is often highly harmful, resulting in dramatic effects both on health and safety aspects. The indoor industrial abatement systems, adopted to purify the air, are typically applied to the emission points. The processed air is subsequently emitted outside. In this study we present the experimental results of three-stage wet scrubber systems installed in the industrial workplace of a (i) fiberglass processing plant, where the highest exposure levels to volatile compounds are nowadays today monitored,and of a (ii) waste-to-energy plant, characterized by a very high particulate matter level. The adopted technology, to be used as complementing strategy,does not require special disposal procedures and the processed air is re-emitted in the same work environment for the benefit of the work operators. The operation of the scrubbers network during the working a...

  4. Treatment of desizing wastewater from the textile industry by wet air oxidation

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper describes the application of wet air oxidation to the treatment of desizing wastewater from two textile companies. A two-liter high temperature, high pressure autoclave reactor was used in the study. The range of operating temperatures examined was between 150 and 290℃, and the partial pressure of oxygen ranged from 0. 375 to 2.25 MPa. Variations in pH,CODCr and TOD content were monitored during each experiment and used to assess the extent of conversion of the process. The effects of temperature, pressure and reaction time were explored extensively. More than 90 % CODCr reduction and 80 % TOC removal have been obtained. The results have also been demonstrated that WAO is a suitable pre-treatment methods due to improvement of the BOD5/CODCr ratio of desizing wastewater. The reaction kinetics of wet air oxidation of desizing wastewater has been proved to be two steps, a fast reaction followed by a slow reaction stage.

  5. The Study of LeachateTreatment by Using Three Advanced Oxidation Process Based Wet air Oxidation

    Directory of Open Access Journals (Sweden)

    Behroz Karimi

    2013-01-01

    Full Text Available Wet air oxidation is regarded as appropriate options for wastewater treatment with average organic compounds. The general purpose of this research is to determine the efficiency of three wet air oxidation methods, wet oxidation with hydrogen peroxide and absorption with activated carbon in removing organic matter and nitrogenous compounds from Isfahan's urban leachate. A leachate sample with the volume of 1.5 liters entered into a steel reactor with the volume of three liters and was put under a 10-bar pressure, at temperatures of 100, 200, and 300[degree sign] as well as three retention times of 30, 60, and 90 minutes. The sample was placed at 18 stages of leachate storage ponds in Isfahan Compost Plant with the volume of 20 liters, using three WPO, WAO methods and a combination of WAO/GAC for leachate pre-treatment. Thirty percent of pure oxygen and hydrogen peroxide were applied as oxidation agents. The COD removal efficiency in WAO method is 7.8-33.3%, in BOD is 14.7-50.6%, the maximum removal percentage (efficiency for NH4-N is 53.3% and for NO3-N is 56.4-73.9%. The removal efficiency of COD and BOD5 is 4.6%-34 and 24%-50 respectively in WPO method. Adding GAC to the reactor, the removal efficiency of all parameters was improved. The maximum removal efficiency was increased 48% for COD, 31%-43.6 for BOD5 by a combinational method, and the ratio of BOD5/COD was also increased to 90%. In this paper, WAO and WPO process was used for Leachate pre-treatment and WAO/GAC combinational process was applied for improving the organic matter removal and leachate treatment; it was also determined that the recent process is much more efficient in removing resistant organic matter.

  6. Intrinsic catalytic properties of extruded clay honeycomb monolith toward complete oxidation of air pollutants.

    Science.gov (United States)

    Assebban, Mhamed; El Kasmi, Achraf; Harti, Sanae; Chafik, Tarik

    2015-12-30

    The present work highlights the intrinsic catalytic properties of extruded clay honeycomb monolith toward complete oxidation of various air pollutants namely CO, methane, propane, acetylene, propene, n-butene, methanol, ethanol, n-propanol, n-butanol, acetone, dimethyl ether, benzene, toluene, o-xylene, monochlorobenzene and 1,2-dichlorobenzene. Total catalytic conversion was achieved for all tested compounds with different behaviors depending on pollutants' structural and chemical nature. The comparison of T50 values obtained from light-off curves allowed the establishment of the following reactivity sequence: ketone>alcohol>ether>CO>alkyne>aromatic>alkene>chlorinated aromatic>alkane. The intrinsic catalytic performances of the natural clay was ascribed to the implication of a quite complex mixture constituted by OH groups (Brønsted acids) and coordinately-unsaturated cations, such as Al(3+), Fe(3+) and Fe(2+) (Lewis acids). Hence, the combination of the clay's intrinsic catalytic performances and easier extrudability suggests a promissory potential for application in air pollution control. PMID:26259164

  7. Catalytically stabilized combustion of lean methane-air-mixtures: a numerical model

    Energy Technology Data Exchange (ETDEWEB)

    Dogwiler, U.; Benz, P.; Mantharas, I. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The catalytically stabilized combustion of lean methane/air mixtures has been studied numerically under conditions closely resembling the ones prevailing in technical devices. A detailed numerical model has been developed for a laminar, stationary, 2-D channel flow with full heterogeneous and homogeneous reaction mechanisms. The computations provide direct information on the coupling between heterogeneous-homogeneous combustion and in particular on the means of homogeneous ignitions and stabilization. (author) 4 figs., 3 refs.

  8. Role of Bismuth Oxide in Bi-MCo2O4(M=Co,Ni,Cu,Zn) Catalysts for Wet Air Oxidation of Acetic Acid

    Institute of Scientific and Technical Information of China (English)

    JIANG Peng-bo; CHENG Tie-xin; ZHUANG Hong; CUI Xiang-hao; BI Ying-li; ZHEN Kai-ji

    2004-01-01

    Two series of cobalt(Ⅲ)-containing spinel catalysts were prepared by the decomposition of the corresponding nitrates. The catalysts doped with bismuth oxide exhibit a higher activity in the wet air oxidation of acetic acid than those without dopant bismuth oxide. The catalysts were investigated by XRD, TEM, ESR, UV-DRS and XPS, and the interaction between Co and Bi was studied as well. It has been found that nano-sized bismuth oxide is paved on the surface of cobalt spinel crystal and the structures of cobalt(Ⅲ)-containing spinel are still maintained. The shift of the binding energy of Bi4f7/2 is related to the catalytic activity of these catalysts doped with bismuth oxide.

  9. Degradation of H-acid in aqueous solution by microwave assisted wet air oxidation using Ni-loaded GAC as catalyst

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yao-bin; QUAN Xie; ZHAO Hui-min; CHEN Shuo; YANG Feng-lin

    2005-01-01

    A novel process, microwave assisted catalytic wet air oxidation(MW-CWO), was applied for the degradation of H-acid( 1-amino8-naphthol-3, 6-disulfonic acid) in aqueous solution. Ni-loaded granular activated carbon (GAG), prepared by immersion-calcination method, was used as catalyst. The results showed that the MW-CWO process was very effective for the degradation of H-acid in aqueous solution under atmospheric pressure with 87.4% TOC (total organic carbon) reduction in 20 min. Ni on GAC existed in the form of NiO as specified by XRD. Loss of Ni was significant in the initial stage, and then remained almost constant after 20 min reaction. BET surface area results showed that the surface property of GAC after MW-CWO process was superior to that of blank GAC.

  10. Experimental evaluation of dry/wet air-cooled heat exchangers. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, S.G.; Gruel, R.L.; Huenefeld, J.C.; Eschbach, E.J.; Johnson, B.M.; Kreid, D.K.

    1982-08-01

    The ultimate goal of this project was to contribute to the development of improved cooling facilities for power plants. Specifically, the objective during FY-81 was to experimentally determine the thermal performance and operating characteristics of an air-cooled heat exchanger surface manufactured by the Unifin Company. The performance of the spiral-wound finned tube surface (Unifin) was compared with two inherently different platefin surfaces (one developed by the Trane Co. and the other developed by the HOETERV Institute) which were previously tested as a part of the same continuing program. Under dry operation the heat transfer per unit frontal area per unit inlet temperature difference (ITD) of the Unifin surface was 10% to 20% below that of the other two surfaces at low fan power levels. At high fan power levels, the performances of the Unifin and Trane surfaces were essentially the same, and 25% higher than the HOETERV surface. The design of the Unifin surface caused a significantly larger air-side pressure drop through the heat exchanger both in dry and deluge operation. Generally higher overall heat transfer coefficients were calculated for the Unifin surface under deluged operation. They ranged from 2.0 to 3.5 Btu/hr-ft/sup 2/-/sup 0/F as compared to less than 2.0 Btu hr-ft/sup 2/-/sup 0/F for the Trane and HOETERV surfaces under similar conditions. The heat transfer enhancement due to the evaporative cooling effect was also measureably higher with the Unifin surface as compared to the Trane surface. This can be primarily attributed to the better wetting characteristics of the Unifin surface. If the thermal performance of the surfaces are compared at equal face velocities, the Unifin surface is as much as 35% better. This method of comparison accounts for the wetting characteristics while neglecting the effect of pressure drop. Alternatively the surfaces when compared at equal pressure drop essentially the same thermal performance.

  11. Tailoring activated carbons as catalyst for catalytic wet air oxidation of phenol

    OpenAIRE

    Baricot Mendoza, Maretva Denise

    2008-01-01

    Debido al marcado desarrollo que han tenido las actividades industriales en el mundo, el acceso al agua potable es cada vez más difícil. Durante el último siglo el consumo mundial de agua se ha incrementado 10 veces y de acuerdo con información de la Organización Mundial de la Salud 1.1 miles de millones de personas no tienen acceso a agua potable y 2.4 miles de millones no disponen de las condiciones sanitarias apropiadas. Adicionalmente, sólo 0.8% de la reserva global de agua es apta para e...

  12. Dry/wet performance of a plate-fin air-cooled heat exchanger with continuous corrugated fins

    International Nuclear Information System (INIS)

    The performance and operating characteristics of a plate-fin heat exchanger in dry/wet or deluge operations was experimentally determined. Development of the deluge heat/mass transfer model continued. The experiments were conducted in a specially-designed wind tunnel at the PNL. Air that was first heated and humidified to specified conditions was circulated at a controlled rate through a 2 ft x 6 ft heat exchanger module. The heat exchanger used in the tests was a wavy surface, plate fin on tube configuration. Hot water was circulated through the tubes at high flow rates to maintain an essentially isothermal condition on the tube side. Deionized water sprayed on the top of the vertically oriented plate fins was collected at the bottom of the core and recirculated. Instrumentation was provided for measurement of flow rates and thermodynamic conditions in the air, in the core circulation water, and in the deluge water. Measurements of the air side pressure drop and heat rejection rate were made as a function of air flow rate, air inlet temperature and humidity, deluge water flow rate, and the core inclination from the vertical. An overall heat transfer coefficient and an effective deluge film convective coefficient was determined. The deluge model, for predicting heat transfer from a wet finned heat exchanger was further developed and refined, and a major extension of the model was formulated that permits simultaneous calculation of both the heat transfer and evaporation rates from the wetted surface. The experiments showed an increase in the heat rejection rate due to wetting, accompanied by a proportional increase in the air side pressure drop. For operation at the same air side pressure drop, the enhancement ratio Q/sub w//Q/sub d/ varied between 2 and 5 for the conditions tested. Thus, the potential enhancement of heat transfer due to wetting can be substantial

  13. Dry/wet performance of a plate-fin air-cooled heat exchanger with continuous corrugated fins

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, S.G.; Kreid, D.K.; Johnson, B.M.

    1981-01-01

    The performance and operating characteristics of a plate-fin heat exchanger in dry/wet or deluge operations was experimentally determined. Development of the deluge heat/mass transfer model continued. The experiments were conducted in a specially-designed wind tunnel at the PNL. Air that was first heated and humidified to specified conditions was circulated at a controlled rate through a 2 ft x 6 ft heat exchanger module. The heat exchanger used in the tests was a wavy surface, plate fin on tube configuration. Hot water was circulated through the tubes at high flow rates to maintain an essentially isothermal condition on the tube side. Deionized water sprayed on the top of the vertically oriented plate fins was collected at the bottom of the core and recirculated. Instrumentation was provided for measurement of flow rates and thermodynamic conditions in the air, in the core circulation water, and in the deluge water. Measurements of the air side pressure drop and heat rejection rate were made as a function of air flow rate, air inlet temperature and humidity, deluge water flow rate, and the core inclination from the vertical. An overall heat transfer coefficient and an effective deluge film convective coefficient was determined. The deluge model, for predicting heat transfer from a wet finned heat exchanger was further developed and refined, and a major extension of the model was formulated that permits simultaneous calculation of both the heat transfer and evaporation rates from the wetted surface. The experiments showed an increase in the heat rejection rate due to wetting, accompanied by a proportional increase in the air side pressure drop. For operation at the same air side pressure drop, the enhancement ratio Q/sub w//Q/sub d/ varied between 2 and 5 for the conditions tested. Thus, the potential enhancement of heat transfer due to wetting can be substantial.

  14. Methodology to determine the appropriate amount of excess air for the operation of a gas turbine in a wet environment

    Energy Technology Data Exchange (ETDEWEB)

    Lugo-Leyte, R.; Zamora-Mata, J.M.; Torres-Aldaco, A. [Universidad Autonoma Metropolitana-Iztapalapa, Departamento de Ingenieria de Procesos e Hidraulica, San Rafael Atlixco 186, Col Vicentina 09340, Iztapalapa, Mexico, D.F. (Mexico); Toledo-Velazquez, M. [Instituto Politecnico Nacional, Escuela Superior de Ingenieria Mecanica y Electrica, Seccion de Estudios de Posgrado e Investigacion, Laboratorio de Ingenieria Termica e Hidraulica Aplicada, Unidad Profesional Adolfo Lopez Mateos, Edificio 5, 3er piso SEPI-ESIME, C.P. 07738, Col. Lindavista, Mexico D.F. (Mexico); Salazar-Pereyra, M. [Tecnologico de Estudios Superiores de Ecatepec, Division de Ingenieria Mecatronica e Industrial, Posgrado en Ciencias en Ingenieria Mecatronica, Av. Tecnologico s/n, Col. Valle de Anahuac, C.P. 55210, Ecatepec de Morelos, Estado de Mexico (Mexico)

    2010-02-15

    This paper addresses the impact of excess air on turbine inlet temperature, power, and thermal efficiency at different pressure ratios. An explicit relationship is developed to determine the turbine inlet temperature as a function of excess air, pressure ratio and relative humidity. The effect of humidity on the calculation of excess air to achieve a pre-established power output is analyzed and presented. Likewise it is demonstrated that dry air calculations provide a valid upper bound for the performance of a gas turbine under a wet environment. (author)

  15. An investigation of turbulent catalytically stabilized channel flow combustion of lean hydrogen - air mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Mantzaras, I.; Benz, P.; Schaeren, R.; Bombach, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The catalytically stabilised thermal combustion (CST) of lean hydrogen-air mixtures was investigated numerically in a turbulent channel flow configuration using a two-dimensional elliptic model with detailed heterogeneous and homogeneous chemical reactions. Comparison between turbulent and laminar cases having the same incoming mean properties shows that turbulence inhibits homogeneous ignition due to increased heat transport away from the near-wall layer. The peak root-mean-square temperature and species fluctuations are always located outside the extent of the homogeneous reaction zone indicating that thermochemical fluctuations have no significant influence on gaseous combustion. (author) 4 figs., 6 refs.

  16. Study on dynamics characteristics of wet air oxidation of non-ionic surfactants

    Institute of Scientific and Technical Information of China (English)

    ZENG XinPing; TANG WenWei; ZHAO JianFu; GU GuoWei

    2008-01-01

    Wet air oxidation is an effective method to deal with highly concentrated nondegradable emulsification wastewater which contains non-ionic surfactants. This article illustrates our investigation on dynamic characteristics of wet air oxidation of typical non-ionic surfactants like polyether, phenol ether and widely used alcohol ether. The experimental results indicated that the oxidation rate of polyether, phenol ether and alcohol ether obviously ascended as the temperature rose. A good oxidation effect was available at 240℃. The TOC removal rate could reach 88.0%, 94% and 91.5%, after 125 min reaction. Alcohol ether was prone to an easier oxidation compared with polyether and phenol ether when the temperature was 220℃ or below. The oxidation rate of alcohol ether was higher than that of polyether at 160℃, while the oxidation rate of polyether was higher than that of phenol ether between 180℃ and 220℃. During the later period of the reaction at 240℃, the rate of phenol ether was higher than that of alcohol ether, which was still higher than that of polyether. Partitioned first order kinetics model analysis showed that the apparent activation energy of alcohol ether was lower than that of both polyether and phenol ether in the leading stage and lagging stage, and it was easy to acquire a higher oxidation rate for alcohol ether at low temperature. Three parameter general dynamics model analyses showed that the reason why the oxidation rate of polyether was lower than that of alcohol ether was that the oxidation of polyether was more apt to be converted to intermediate production than that of alcohol ether, whereas between 200℃ and 220℃, the direct oxidation rate of polyether and the oxidation rate of intermediate product were obviously lower than that of alcohol ether. The apparent activation energy of direct and indirect oxidation of polyether was 43.37 and 60.45 kJ·mol-1, respectively, while the corresponding apparent activation energy of alcohol

  17. Study on dynamics characteristics of wet air oxidation of non-ionic surfactants

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Wet air oxidation is an effective method to deal with highly concentrated nondegradable emulsification wastewater which contains non-ionic surfactants. This article illustrates our investigation on dynamic characteristics of wet air oxidation of typical non-ionic surfactants like polyether, phenol ether and widely used alcohol ether. The experimental results indicated that the oxidation rate of polyether, phenol ether and alcohol ether obviously ascended as the temperature rose. A good oxidation effect was available at 240℃. The TOC removal rate could reach 88.0%, 94% and 91.5%, after 125 min reaction. Alcohol ether was prone to an easier oxidation compared with polyether and phenol ether when the temperature was 220℃ or below. The oxidation rate of alcohol ether was higher than that of polyether at 160℃, while the oxidation rate of polyether was higher than that of phenol ether between 180℃ and 220℃. During the later period of the reaction at 240℃, the rate of phenol ether was higher than that of alcohol ether, which was still higher than that of polyether. Partitioned first order kinetics model analy-sis showed that the apparent activation energy of alcohol ether was lower than that of both polyether and phenol ether in the leading stage and lagging stage, and it was easy to acquire a higher oxidation rate for alcohol ether at low temperature. Three parameter general dynamics model analyses showed that the reason why the oxidation rate of polyether was lower than that of alcohol ether was that the oxidation of polyether was more apt to be converted to intermediate production than that of alcohol ether, whereas between 200℃ and 220℃, the direct oxidation rate of polyether and the oxidation rate of intermediate product were obviously lower than that of alcohol ether. The apparent activation energy of direct and indirect oxidation of polyether was 43.37 and 60.45 kJ?mol?1, respectively, while the corre-sponding apparent activation energy of alcohol

  18. ADVECTION-DIFFUSION NUMERICAL MODEL OF AN AIR POLLUTANT EMITTED FROM AN AREA SOURCE OF PRIMARY POLLUTANT WITH WET DEPOSITION

    Directory of Open Access Journals (Sweden)

    C M SURESHA

    2012-01-01

    Full Text Available A two dimensional advection-diffusion numerical model of air pollutant emitted from an area source of primary pollutant with wet deposition is presented. We study the effect of removal mechanism i.e. wet deposition on primary pollutant with respect to distance and height for stable and neutral cases. The numerical model has been solved by using Crank-Nicolson implicit finite difference technique. Concentration contours are plotted and results are analysed for primary pollutant in stable and neutral atmospheric situations for various meteorological parameters.

  19. Treatment of biomass gasification wastewater using a combined wet air oxidation/activated sludge process

    Energy Technology Data Exchange (ETDEWEB)

    English, C.J.; Petty, S.E.; Sklarew, D.S.

    1983-02-01

    A lab-scale treatability study for using thermal and biological oxidation to treat a biomass gasification wastewater (BGW) having a chemical oxygen demand (COD) of 46,000 mg/l is described. Wet air oxidation (WA0) at 300/sup 0/C and 13.8 MPa (2000 psi) was used to initially treat the BGW and resulted in a COD reduction of 74%. This was followed by conventional activated sludge treatment using operating conditions typical of municipal sewage treatment plants. This resulted in an additional 95% COD removal. Overall COD reduction for the combined process was 99%. A detailed chemical analysis of the raw BGW and thermal and biological effluents was performed using gas chromatography/mass spectrometry (GC/MS). These results showed a 97% decrease in total extractable organics with WA0 and a 99.6% decrease for combined WA0 and activated sludge treatment. Components of the treated waters tended to be fewer in number and more highly oxidized. An experiment was conducted to determine the amount of COD reduction caused by volatilization during biological treatment. Unfortunately, this did not yield conclusive results. Treatment of BGW using WA0 followed by activated sludge appears to be very effective and investigations at a larger scale are recommended.

  20. ESR ST study of hydroxyl radical generation in wet peroxide system catalyzed by heterogeneous ruthenium

    NARCIS (Netherlands)

    Rokhina, E.V.; Golovina, E.A.; As, van H.; Virkutyte, J.

    2009-01-01

    Ru-based catalysts gained popularity because of their applicability for a variety of processes, including carbon monoxide oxidation, wet air catalytic oxidation and wastewater treatment. The focus of a current study was generation of hydroxyl radicals in the wet peroxide system catalyzed by heteroge

  1. Zimpro's biophysical treatment and wet-air-regeneration-system engineering study for H-COAL wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Churton, B.M.

    1982-12-01

    As part of an overall environmental evaluation of the H-COAL liquefaction process, sour water treatability studies have been performed. These studies consisted of the following major components: H-COAL sour and stripped water characterization study; Zimpro's biophysical treatability and characterization study on H-COAL Wastwater; Zimpro's biophysical treatment system stress testing; Zimpro's biophysical treatment and wet air regeneration system engineering study; engineering analysis of reuse concepts for treated H-COAL wastewater; and evaluation of reverse osmosis treatment of treated H-COAL wastewater. These studies indicate that H-COAL Sour Water can be successfully treated for reuse or for discharge to public waters. Zimpro performed the first three studies on the biophysical treatment utilizing Powdered Activated Carbon Treatment (PACT). The PACT studies achieved the following results: Five-day biochemical oxygen demand (BOD/sub 5/) removal was > 98.8%; chemical oxygen demand (COD) removal was 85 to 87%; esentailly complete nitrification was achieved; phenolics removal was > 99%; priority pollutants were removed to levels below Environmental Protection Agency (EPA) defined detection limits; PACT operated well using wet air regenerated carbon; and carbon recovery was approx. 90% in the wet air regeneration step. The third step in the Zimpro studies was a larger scale pilot investigation to: Confirm information developed in bench-scale experiments on a larger scale; provide performance data necessary to evaluate the PACTs Wet Air Regeneration System; optimize PACT operating conditions; produce treatment wastewater for additional testing; and perform a stress test at elevated concentrations of cyanide and thiocyanate. The results of the third Zimpro study are presented here.

  2. Air-side performance evaluation of three types of heat exchangers in dry, wet and periodic frosting conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ping [Zhejiang Vocational College of Commerce, Hangzhou, Binwen Road 470 (China); Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign 1206 West Green Street, Urbana, IL 61801 (United States); Hrnjak, P.S. [Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign 1206 West Green Street, Urbana, IL 61801 (United States)

    2009-08-15

    The performances of three types of heat exchangers that use the louver fin geometry: (1) parallel flow parallel fin with extruded flat tubes heat exchanger (PF{sup 2}), (2) parallel flow serpentine fin with extruded flat tubes heat exchanger (PFSF) and (3) round tube wave plate fin heat exchanger (RTPF) have been experimentally studied under dry, wet and frost conditions and results are presented. The parameters quantified include air-side pressure drop, water retention on the surface of the heat exchanger, capacity and overall heat transfer coefficient for air face velocity 0.9, 2 and 3 m/s, air humidity 70% and 80% and different orientations. The performances of three types of heat exchanger are compared and the results obtained are presented. The condensate drainage behavior of the air-side surface of these three heat exchanger types was studied using both the dip testing method and wind tunnel experiment. (author)

  3. Microlith-Based Catalytic Reactor for Air Quality and Trace Contaminant Control Applications

    Science.gov (United States)

    Vilekar, Saurabh; Hawley, Kyle; Junaedi, Christian; Crowder, Bruce; Prada, Julian; Mastanduno, Richard; Perry, Jay L.; Kayatin, Matthew J.

    2015-01-01

    Traditionally, gaseous compounds such as methane, carbon monoxide, and trace contaminants have posed challenges for maintaining clean air in enclosed spaces such as crewed spacecraft cabins as they are hazardous to humans and are often difficult to remove by conventional adsorption technology. Catalytic oxidizers have provided a reliable and robust means of disposing of even trace levels of these compounds by converting them into carbon dioxide and water. Precision Combustion, Inc. (PCI) and NASA - Marshall (MSFC) have been developing, characterizing, and optimizing high temperature catalytic oxidizers (HTCO) based on PCI's patented Microlith® technology to meet the requirements of future extended human spaceflight explorations. Current efforts have focused on integrating the HTCO unit with a compact, simple recuperative heat exchanger to reduce the overall system size and weight while also reducing its energy requirements. Previous efforts relied on external heat exchangers to recover the waste heat and recycle it to the oxidizer to minimize the system's power requirements; however, these units contribute weight and volume burdens to the overall system. They also result in excess heat loss due to the separation of the HTCO and the heat recuperator, resulting in lower overall efficiency. Improvements in the recuperative efficiency and close coupling of HTCO and heat recuperator lead to reductions in system energy requirements and startup time. Results from testing HTCO units integrated with heat recuperators at a variety of scales for cabin air quality control and heat melt compactor applications are reported and their benefits over previous iterations of the HTCO and heat recuperator assembly are quantified in this paper.

  4. Sewage-sludge-derived carbonaceous materials for catalytic wet hydrogen peroxide oxidation of m-cresol in batch and continuous reactors.

    Science.gov (United States)

    Yu, Yang; Wei, Huangzhao; Yu, Li; Wang, Wei; Zhao, Ying; Gu, Bin; Sun, Chenglin

    2016-01-01

    In this study, four sewage-sludge-derived carbonaceous materials (SWs) were evaluated for their catalytic wet hydrogen peroxide oxidation (CWPO) performance of m-cresol in batch reactor and continuous reactor, respectively. The SWs were produced by carbonization (SW); carbonization with the addition of CaO (CaO-SW); HNO3 pretreatment (HNO3-SW) and steam activation (Activated-SW). The properties of SW catalysts were assessed by thermogravimetric analysis, Brunauer-Emmett-Teller, Fourier Transform Infrared Spectroscopy, X-ray Fluorescence, Scanning electron microscopy, energy dispersive X-ray analysis and zeta potential. The results showed that SW treated by HNO3 (HNO3-SW) had a high conversion of m-cresol in batch reactor and continuous reactor, respectively. Under the conditions of batch reaction (Cm-cresol = 100 mg L(-1), CH2O2 = 15.7 mmol L(-1), initial pH=7.0, 0.5 g L(-1) catalyst, 80°C, 180 min adsorption and 210 min oxidation), the conversion of m-cresol reached 100% and total organic carbon removal was 67.1%. It had a high catalytic activity and stability on the treatment of m-cresol in CWPO for more than 1100 h. Furthermore, a possible reaction mechanism for the oxidation of m-cresol to 2-methyl-p-benzoquinone by CWPO was proposed. PMID:26109374

  5. THE INFLUENCE OF AIR-DRYING ON HYPER-REMINERALIZATION OF DEMINERALIZED DENTIN - A STUDY ON BULK AS WELL AS ON THIN WET SECTION OF BOVINE DENTIN

    NARCIS (Netherlands)

    INABA, D; IIJIMA, Y; TAKAGI, O; RUBEN, J; ARENDS, J

    1995-01-01

    The influence of air-drying on the remineralization of demineralized bovine dentine was examined in wet bulk samples, in dried bulk samples as well as in wet thin sections. Bulk samples of bovine dentine were first demineralized in an acidic gel (pH = 5) at 37 degrees C for 3 weeks. After 24-hour pr

  6. Research on Synergy of Combining Electrochemical Oxidation and Catalytic Wet Oxidation%电场效应与催化湿式氧化协同作用研究

    Institute of Scientific and Technical Information of China (English)

    王华; 李光明; 张芳; 黄菊文

    2009-01-01

    A new catalytic wet oxidation fixed-bed reactor combined with three-dimensional electric-field was developed to investigate catalytic wet oxidation, electrochemical oxidation and electroassisted catalytic wet oxidation of the solution containing phenol in the presence of a catalyst Mn-Sn-Sb-3/γ-Al_2O_3 . Good eleetroassisted catalytic wet oxidation efficiency was obtained in the setup for the combination system even at mild conditions ( T = 130℃, po_2 =1.0 MPa) that the phenol conversion and TOC reduction were up to 94.0% and 88.4% after 27 min treatment, respectively. The result also shows that the rate constants of electroassisted catalytic wet oxidation are much higher than that of not only both catalytic wet oxidation and electrochemical oxidation process alone but also additive efficiencies of catalytic wet oxidation and electrochemical oxidation processes, which indicates an apparent synergetic effect between CWO and ECO processes.%在自行研制开发的一套固定床和复合三维电场一体化连续式催化湿式氧化反应器中,采用浸渍法制备的Mn-Sn-Sb-3/γAl_2O_3催化剂,实验研究了苯酚催化湿式氧化、电催化氧化以及电场效应下的催化湿式氧化过程的行为.结果表明,一体化反应器在较低反应温度(T=130℃)和氧分压(Po_2=1.0 MPa)下即可获得相当满意的处理效果,空时仅为27min时苯酚和TOC的去除率就分别可达到94.0%和88.4%.电场效应下的催化湿式氧化协同降解苯酚的反应速率常数大于单独电催化或催化湿式氧化降解苯酚的反应速率常数,而且还大大超过两者之和,电催化氧化对催化湿式氧化工艺存在明显的协同增效作用.

  7. Impact of Hong Kong's Voluntary Catalytic Converter Replacement Programme on Roadside Air Quality

    Science.gov (United States)

    Simpson, I. J.; Guo, H.; Louie, P. K. K.; Luk, C.; Lyu, X.; Meinardi, S.; Yam, Y. S.; Blake, D. R.

    2015-12-01

    As part of its ongoing policies to improve roadside air quality, in 2013 the Hong Kong government launched an incentive programme to replace catalytic converters and oxygen sensors in taxis and light buses mainly fueled by liquefied petroleum gas (LPG). The majority of replacements occurred from October 2013 to April 2014, with 75% of eligible vehicles participating in the programme, or 16,472 vehicles. Based on taxi exhaust measurements at a Hong Kong vehicle testing facility, the concentrations of n-butane, propane and i-butane (the primary components of LPG) decreased by 97% following the replacements. To determine the impact of the programme on roadside air quality, long-term measurements of volatile organic compounds (VOCs) were analyzed before, during and after the replacement programme, mainly at a busy roadside location in Mong Kok, Hong Kong. A clear decrease in the levels of major pollutants associated with LPG vehicle exhaust was observed at the roadside. For example, average (± 1 standard deviation) n-butane levels from October to April decreased from 13.0 ± 3.6 and 13.9 ± 2.6 ppbv in the two years preceding the programme, to 9.2 ± 2.9 ppbv during the programme, to 6.2 ± 1.7 ppbv the year after the programme. By contrast, compounds such as i-pentane that are not strongly associated with LPG or with LPG exhaust remained steady, averaging 0.90 ± 0.34, 1.01 ± 0.31, 0.93 ± 0.37, and 0.91 ± 0.42 ppbv from October to April of 2011/12, 2012/13, 2013/14 and 2014/15, respectively. Impacts of the programme on roadside levels of nitrogen oxides (NOx) and ozone (O3) will also be discussed. Because many taxis are high mileage vehicles that travel several hundred kilometers daily, their catalytic converters need to be replaced approximately every 18 months. Therefore ongoing vehicle maintenance will be required in order to preserve the gains made from this initial subsidy programme.

  8. Analisis Pengaruh Salinitas dan Temperatur Air Laut pada Wet Underwater Welding terhadap Laju Korosi

    OpenAIRE

    Adrian Dwilaksono; Heri Supomo; Triwilaswandio Wuruk Pribadi

    2013-01-01

    Struktur konstruksi badan kapal lambat laut mengalami kerusakan . Apabila kapal mengalami kerusakan pada konisi darurat, pekerjaan las bawah air menjadi hal yang diutamakan. Sedangkan faktor korosi pada pengelasan basah bawah air merupakan masalah yang pasti terjadi. Melalu penelitian ini dikaji perbandingan laju korosi sambungan las material baja karbon rendah yang diberi perlakuan pengelasan basah bawah air dengan salinitas 33‰ , 35‰ dan suhu 200C, 250C. Dari keempat variasi pengelasan ters...

  9. Development of a New Type of Green Switch Air Entraining Agent for Wet-Mix Shotcrete and Its Engineering Application

    Directory of Open Access Journals (Sweden)

    Guoming Liu

    2016-01-01

    Full Text Available Air entraining agent (AEA can bring a lot of microbubbles into fresh concrete for improving its fluidity; however, high fluidity has adverse effect on the shootability of wet-mix shotcrete. In order to solve the contradictory issue, the paper developed a new type of green switch air entraining agent (GSAE that can improve both the pumpability and shootability. The single-admixture and combination tests containing foaming ability and surface tension were performed with Deer agitator and automatic tension meter. The new AEA was developed with two constituents A and B. A was prepared with Sapindus mukorossi(S-1, dodecyl trimethyl ammonium chloride(1231, and polyacrylamide. B was prepared with lauryl sodium sulfate (K12 and silicone oil. The mass mix proportion was S-1 : 1231 : polyacrylamide : K12 : silicone oil = 1 : 0.33 : 0.2 : 0.33 : 0.47. The application method of GSAE proposed that A was premixed with fresh concrete and then B was added at nozzle. Experimental investigation showed that the optimal mixing amount of GSAE was 0.1%–0.2% relative to cement. All performance measured of wet-mix shotcrete with 0.12% GSAE met the first-grade product requirements of the China National Standard. Compared with the conventional type of AEA, the proposed GSAE is capable of effectively improving pumpability and shootability.

  10. Wet chemical treatments of high purity Ge crystals for γ-ray detectors: Surface structure, passivation capabilities and air stability

    Energy Technology Data Exchange (ETDEWEB)

    Carturan, S., E-mail: carturan@lnl.infn.it [Department of Physics and Astronomy, University of Padova, Padova (Italy); INFN, Laboratori Nazionali di Legnaro, Legnaro, Padova (Italy); Maggioni, G. [Department of Physics and Astronomy, University of Padova, Padova (Italy); INFN, Laboratori Nazionali di Legnaro, Legnaro, Padova (Italy); Rezvani, S.J. [Department of Physics, University of Camerino, Camerino, Macerata (Italy); Gunnella, R. [Department of Physics, University of Camerino, Camerino, Macerata (Italy); INFN, Laboratori Nazionali di Frascati, Frascati (Italy); Pinto, N. [Department of Physics, University of Camerino, Camerino, Macerata (Italy); INFN, Sezione di Perugia, Perugia (Italy); Gelain, M. [Department of Physics and Astronomy, University of Padova, Padova (Italy); INFN, Laboratori Nazionali di Legnaro, Legnaro, Padova (Italy); Napoli, D.R. [INFN, Laboratori Nazionali di Legnaro, Legnaro, Padova (Italy)

    2015-07-01

    Aiming at the production of HPGe diodes for γ-ray detection, surface passivation of the pristine Germanium surface is pursued by treatment of freshly etched, highly reactive Ge (100) surface by different chemicals, to obtain chemisorbed species with sufficient insulating properties for allowing high voltage application (up to 1100 V) with low leakage currents (lower than 30 pA). (100) surface termination of Ge crystal with hydride, methoxide, and sulphide is carried out by wet chemical treatments using suitable reactants. The chemical composition of the newly formed monolayers is investigated with regards to the nature of chemical bonding with Ge atop atoms. To this aim Fourier Transform Infrared Spectrometry (FTIR) and X-ray Photoelectron Spectroscopy (XPS) were used; the performance as dielectric layer of each native Ge compound/complex is measured directly from I–V measurements of a HPGe diode. Atomic stability of each surface layer is monitored detecting structural changes after air exposure by XPS and FTIR spectroscopies and by relevant leakage current variations. - Highlights: • Different surface passivations were applied to HPGe by wet chemical methods. • New chemical bonds were characterized by FTIR and XPS. • Air stability: hydride and sulphide treatments display the best oxidation resistance. • I–V measurements: all the treatments provided efficient passivation.

  11. Catalytic Destruction of a Surrogate Organic Hazardous Air Pollutant as a Potential Co-benefit for Coal-fired Selective Catalyst Reduction Systems

    Science.gov (United States)

    Catalytic destruction of benzene (C6H6), a surrogate for organic hazardous air pollutants (HAPs) produced from coal combustion, was investigated using a commercial selective catalytic reduction (SCR) catalyst for evaluating the potential co-benefit of the SCR technology for reduc...

  12. Analisis Pengaruh Salinitas dan Temperatur Air Laut pada Wet Underwater Welding terhadap Laju Korosi

    Directory of Open Access Journals (Sweden)

    Adrian Dwilaksono

    2013-03-01

    Full Text Available Struktur konstruksi badan kapal lambat laut mengalami kerusakan . Apabila kapal mengalami kerusakan pada konisi darurat, pekerjaan las bawah air menjadi hal yang diutamakan. Sedangkan faktor korosi pada pengelasan basah bawah air merupakan masalah yang pasti terjadi. Melalu penelitian ini dikaji perbandingan laju korosi sambungan las material baja karbon rendah yang diberi perlakuan pengelasan basah bawah air dengan salinitas 33‰ , 35‰ dan suhu 200C, 250C. Dari keempat variasi pengelasan tersebut diberikan variasi ketebalan pelat sebagai pembanding. Penelitian laju korosi dilakukan dengan pengujian terhadap material baja A36 yang dilas menggunakan metode SMAW pada pengelasan basah bawah air pada posisi 1G (datar dengan elektroda AWS E-6013 yang dilapisi isolasi yang bersifat kedap air. Dari data pengujian laju korosi  diketahui bahwa pengelasan basah bawah air dengan salinitas 35‰ lebih tinggi di bandingkan dengan pengelasan basah bawah air dengan salinitas 33‰, sedangkan untuk pengujian laju korosi dengan variasi suhu diketahui bahwa dengan suhu 250C cenderung lebih besar, meskipun hasil nya tidak signifikan dibandingkan dengan suhu 200C, dan semakin tebal pelat, laju korosinya juga cenderung lebih tinggi. Hasil pengujian menunjukkan bahwa ketebalan yang berkurang pada Salinitas 33‰ dan Suhu 200C yaitu sebesar 0.2124 (mm/year , untuk Suhu 250C yaitu sebesar 0.2139(mm/year pada plat 10mm, Sedangkan untuk plat 12 mm , suhu 200C yaitu sebesar 0.3203 (mm/year , untuk Suhu 250C yaitu sebesar 0.3205 (mm/year. Untuk Salinitas 35‰ dan Suhu 200C yaitu sebesar 0.4521 (mm/year , untuk Suhu 250C yaitu sebesar 0.4538(mm/year pada plat 10mm, Sedangkan untuk plat 12 mm , suhu 200C yaitu sebesar 0.5547 (mm/year , untuk Suhu 250C yaitu sebesar 0.5550 (mm/year.

  13. Gas Dispersion in Granular Porous Media under Air-Dry and Wet Conditions

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Hamamoto, S; Kawamoto, K;

    2012-01-01

    Subsurface gaseous-phase transport is governed by three gas transport parameters: the air permeability coefficient (ka), gas diffusion coefficient (DP), and gas dispersion coefficient (DH). Among these, DH is the least understood due to hitherto limited research into the relationship between gas...... dispersion. Glass beads and various sands of different shapes (angular and rounded) with mean particle diameters (d50) ranging from 0.19 to 1.51 mm at both air-dry and variable moisture contents were used as granular porous media. Gas dispersion coefficients and gas dispersivities (a = DH/v, where v...... is the pore-gas velocity) were determined by fitting the advection–dispersion equation to the measured breakthrough curves. For all test conditions, DH increased linearly with v. The test results showed that neither soil column length nor diameter had significant effect on gas dispersivity. Under air...

  14. Post-treatment of biologically treated wastewater containing organic contaminants using a sequence of H2O2 based advanced oxidation processes: photolysis and catalytic wet oxidation.

    Science.gov (United States)

    Rueda-Márquez, J J; Sillanpää, M; Pocostales, P; Acevedo, A; Manzano, M A

    2015-03-15

    In this paper the feasibility of a multi-barrier treatment (MBT) for the regeneration of synthetic industrial wastewater (SIWW) was evaluated. Industrial pollutants (orange II, phenol, 4-chlorophenol and phenanthrene) were added to the effluent of municipal wastewater treatment plant. The proposed MBT begins with a microfiltration membrane pretreatment (MF), followed by hydrogen peroxide photolysis (H2O2/UVC) and finishing, as a polishing step, with catalytic wet peroxide oxidation (CWPO) using granular activated carbon (GAC) at ambient conditions. During the microfiltration step (0.7 μm) the decrease of suspended solids concentration, turbidity and Escherichia coli in treated water were 88, 94 and 99%, respectively. Also, the effluent's transmittance (254 nm) was increased by 14.7%. Removal of more than 99.9% of all added pollutants, mineralization of 63% of organic compounds and complete disinfection of total coliforms were reached during the H2O2/UVC treatment step (H2O2:TOC w/w ratio = 5 and an UVC average dose accumulated by wastewater 8.80 WUVC s cm(-2)). The power and efficiency of the lamp, the water transmittance and photoreactor geometry are taken into account and a new equation to estimate the accumulated dose in water is suggested. Remaining organic pollutants with a higher oxidation state of carbon atoms (+0.47) and toxic concentration of residual H2O2 were present in the effluent of the H2O2/UVC process. After 2.3 min of contact time with GAC at CWPO step, 90 and 100% of total organic carbon and residual H2O2 were removed, respectively. Also, the wastewater toxicity was studied using Vibrio fischeri and Sparus aurata larvae. The MBT operational and maintenance costs (O&M) was estimated to be 0.59 € m(-3). PMID:25600300

  15. Abatement of phenolic mixtures by catalytic wet oxidation enhanced by Fenton's pretreatment: Effect of H2O2 dosage and temperature

    International Nuclear Information System (INIS)

    Catalytic wet oxidation (CWO) of a phenolic mixture containing phenol, o-cresol and p-cresol (500 mg/L on each pollutant) has been carried out using a commercial activated carbon (AC) as catalyst, placed in a continuous three-phase reactor. Total pressure was 16 bar and temperature was 127 deg. C. Pollutant conversion, mineralization, intermediate distribution, and toxicity were measured at the reactor outlet. Under these conditions no detoxification of the inlet effluent was found even at the highest catalyst weight (W) to liquid flow rate (QL) ratio used. On the other hand, some Fenton Runs (FR) have been carried out in a batch way using the same phenolic aqueous mixture previously cited. The concentration of Fe2+ was set to 10 mg/L. The influence of the H2O2 amount (between 10 and 100% of the stoichiometric dose) and temperature (30, 50, and 70 deg. C) on phenols conversion, mineralization, and detoxification have been analyzed. Phenols conversion was near unity at low hydrogen peroxide dosage but mineralization and detoxification achieved an asymptotic value at each temperature conditions. The integration of Fenton reagent as pretreatment of the CWO process remarkably improves the efficiency of the CWO reactor and allows to obtain detoxified effluents at mild temperature conditions and relatively low W/QL values. For a given phenolic mixture a temperature range of 30-50 deg. C in the Fenton pretreatment with a H2O2 dosage between 20 and 40% of the stoichiometric amount required can be proposed

  16. CuZnAl Mixed Oxide Catalyst Prepared from Hydrotalcite-like Precursor for Catalytic Wet Oxidation of Phenol%由类水滑石前驱体制备的CuZnAl复合氧化物催化剂催化湿氧化处理苯酚

    Institute of Scientific and Technical Information of China (English)

    孙颖; 杨民; 窦和瑞; 何雨; 王炜; 孙承林

    2003-01-01

    @@ The efficiency of several noble metals for catalytic wet oxidation (CWO) of various pollutants has been demonstrated[1,2]. However, the noble metals are expensive, affecting greatly the economics of the corresponding process.

  17. Sustainability of the Catalytic Activity of a Silica-Titania Composite (STC) for Long-Term Indoor Air Quality Control

    Science.gov (United States)

    Coutts, Janelle L.; Levine, Lanfang H.; Richards, Jeffrey T.

    2011-01-01

    TiO2-assisted photocatalytic oxidation (PCO) is an emerging technology for indoor air quality control and is also being evaluated as an alternative trace contaminant control technology for crew habitats in space exploration. Though there exists a vast range of literature on the development of photocatalysts and associated reactor systems, including catalyst performance and performance-influencing factors, the critical question of whether photocatalysts can sustain their initial catalytic activity over an extended period of operation has not been adequately addressed. For a catalyst to effectively serve as an air quality control product, it must be rugged enough to withstand exposure to a multitude of low concentration volatile organic compounds (VOCs) over long periods of time with minimal loss of activity. The objective of this study was to determine the functional lifetime of a promising photocatalyst - the silica-titania composite (STC) from Sol Gel Solutions, LLC in a real-world scenario. A bench-scale STC-packed annular reactor under continuous irradiation by a UV-A fluorescent black-light blue lamp ((lambda)max = 365 nm) was exposed to laboratory air continuously at an apparent contact time of 0.27 sand challenged with a known concentration of ethanol periodically to assess any changes in catalytic activity. Laboratory air was also episodically spiked with halocarbons (e.g., octafluoropropane), organosulfur compounds (e.g., sulfur hexafluoride), and organosilicons (e.g., siloxanes) to simulate accidental releases or leaks of such VOCs. Total organic carbon (TOC) loading and contaminant profiles of the laboratory air were also monitored. Changes in STC photocatalytic performance were evaluated using the ethanol mineralization rate, mineralization efficiency, and oxidation intermediate (acetaldehyde) formation. Results provide insights to any potential catalyst poisoning by trace halocarbons and organosulfur compounds.

  18. Wet-bulb, dew point, and air temperature trends in Spain

    Science.gov (United States)

    Moratiel, R.; Soriano, B.; Centeno, A.; Spano, D.; Snyder, R. L.

    2016-08-01

    This study analyses trends of mean (T m), maximum (T x), minimum (T n), dew point (T d), and wet-bulb temperatures (T w) on an annual, seasonal, and monthly time scale over Spain during the period 1981-2010. The main purpose was to determine how temperature and humidity changes are impacting on T w, which is probably a better measure of climate change than temperature alone. In this study, 43 weather stations were used to detect data trends using the nonparametric Mann-Kendall test and the Sen method to estimate the slope of trends. Significant linear trends observed for T m, T x, and T n versus year were 56, 58, and 47 % of the weather stations, respectively, with temperature ranges between 0.2 and 0.4 °C per decade. The months with bigger trends were April, May, June, and July with the highest trend for T x. The spatial behaviour of T d and T w was variable, with various locations showing trends from -0.6 to +0.3 °C per decade for T d and from -0.4 to +0.5 °C per decade for T w. Both T d and T w showed negative trends for July, August, September, November, and December. Comparing the trends versus time of each variable versus each of the other variables exhibited poor relationships, which means you cannot predict the trend of one variable from the trend of another variable. The trend of T x was not related to the trend of T n. The trends of T x, T m, and T n versus time were unrelated to the trends versus time of either T d or T w. The trend of T w showed a high coefficient of determination with the trend of T d with an annual value of R 2 = 0.86. Therefore, the T w trend is more related to changes in humidity than temperature.

  19. Correlation between the microstructures of graphite oxides and their catalytic behaviors in air oxidation of benzyl alcohol.

    Science.gov (United States)

    Geng, Longlong; Wu, Shujie; Zou, Yongcun; Jia, Mingjun; Zhang, Wenxiang; Yan, Wenfu; Liu, Gang

    2014-05-01

    A series of graphite oxide (GO) materials were obtained by thermal treatment of oxidized natural graphite powder at different temperatures (from 100 to 200 °C). The microstructure evolution (i.e., layer structure and surface functional groups) of the graphite oxide during the heating process is studied by various characterization means, including XRD, N2 adsorption, TG-DTA, in situ DRIFT, XPS, Raman, TEM and Boehm titration. The characterization results show that the structures of GO materials change gradually from multilayer sheets to a transparent ultrathin 2D structure of the carbon sheets. The concentration of surface COH and HOCO groups decrease significantly upon treating temperature increasing. Benzyl alcohol oxidation with air as oxidant source was carried out to detect the catalytic behaviors of different GO materials. The activities of GO materials decrease with the increase of treating temperatures. It shows that the structure properties, including ultrathin sheets and high specific surface area, are not crucial factors affecting the catalytic activity. The type and amount of surface oxygen-containing functional groups of GO materials tightly correlates with the catalytic performance. Carboxylic groups on the surface of GO should act as oxidative sites for benzyl alcohol and the reduced form could be reoxidized by molecular oxygen.

  20. 湿法烟气脱硫环境下亚硫酸钙的非催化氧化%NON-CATALYTIC OXIDATION KINETICS OF CALCIUM SULFITE IN WET LIMESTONE-GYPSUM FGD PROCESS

    Institute of Scientific and Technical Information of China (English)

    杜谦; 吴少华; 朱群益; 秦裕琨

    2003-01-01

    A study on non-catalytic oxidation kinetics of calcium sulfite is presented under typical conditions of wet flue gas desulfurization (FGD)in this paper. A laboratory-scale mechanically stirred tank reactor is used with continuous feed of both gas and liquid phase. The results show that increasing CaSO3 load from a lower value, the reaction rate increases and is limited by solid sulfite dissolution. The oxidation rate limitation is observed at loads exceeding certain concentration. The rate limitation is possibly caused by solid sulfite solubility or oxygen gas-liquid diffusion. The experimental conclusions are useful for design and operation of the holding tank in forced-oxidation wet FGD.

  1. Study on the active sites of Cu-ZSM-5 in trichloroethylene catalytic combustion with air

    Institute of Scientific and Technical Information of China (English)

    Cheng Hua Xu; Chuan Qi Liu; Yan Zhong; Xiu Zhou Yang; Jian Ying Liu; Ying Chun Yang; Zhi Xiang Ye

    2008-01-01

    The catalytic activity of Cu-ZSM-5 in trichloroethylene (TCE) combustion increases with the increasing skeletal Cu amount and however decreases with the increase of surface amorphous CuO,which is detected by infrared spectroscopy (IR) and diffuse reflectance ultraviolet-visible spectroscopy (DRS-UV-vis),therefore the skeletal Cu species are concluded to be the active sites for the TCE combustion.

  2. Simulation Analysis of Sludge Disposal and Volatile Fatty Acids Production from Gravity Pressure Reactor via Wet Air Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gwon Woo [Biomass and Waste Energy Laboratory, KIER, Daejeon (Korea, Republic of); Seo, Tae Wan; Lee, Hong-Cheol; Hwang, In-Ju [Environmental and Plant Engineering Research Institute, KICT, Goyang (Korea, Republic of)

    2016-04-15

    Efficacious wastewater treatment is essential for increasing sewage sludge volume and implementing strict environmental regulations. The operation cost of sludge treatment amounts up to 50% of the total costs for wastewater treatment plants, therefore, an economical sludge destruction method is crucially needed. Amid several destruction methods, wet air oxidation (WAO) can efficiently treat wastewater containing organic pollutants. It can be used not only for sludge destruction but also for useful by-product production. Volatile fatty acids (VFAs), one of many byproducts, is considered to be an important precursor of biofuel and chemical materials. Its high reaction condition has instituted the study of gravity pressure reactor (GPR) for an economical process of WAO to reduce operation cost. Simulation of subcritical condition was conducted using Aspen Plus with predictive Soave-Redlich-Kwong (PSRK) equation of state. Conjointly, simulation analysis for GPR depth, oxidizer type, sludge flow rate and oxidizer injection position was carried out. At GPR depth of 1000m and flow rate of 2 ton/h, the conversion and yield of VFAs were 92.02% and 0.17g/g, respectively.

  3. Wet air oxidation of resorcinol as a model treatment for refractory organics in wastewaters from the wood processing industry.

    Science.gov (United States)

    Weber, Bernd; Chavez, Alma; Morales-Mejia, Julio; Eichenauer, Sabrina; Stadlbauer, Ernst A; Almanza, Rafael

    2015-09-15

    Wastewater treatment systems are important tools to enhance sustainability in terms of reducing environmental impact and complying with sanitary requirements. This work addresses the wet air oxidation (WAO) process for pre-treatment of phenolic wastewater effluents. The aim was to increase biodegradability prior to a subsequent anaerobic stage. In WAO laboratory experiments using a micro-autoclave, the model compound resorcinol was degraded under different oxygen availability regims within the temperature range 150 °C-270 °C. The activation energy was determined to be 51.5 kJ/mol. Analysis of the products revealed that after 3 h of reaction at 230 °C, 97.5% degradation of resorcinol was achieved. At 250 °C and the same reaction time complete removal of resorcinol was observed. In this case the total organic carbon content was reduced down to 29%, from 118.0 mg/L down to 34.4 mg/L. Under these process conditions, the pollutant was only partially mineralized and the ratio of the biological oxygen demand relative to the chemical oxygen demand, which is 0.07 for resorcinol, was increased to a value exceeding 0.5. The main by-product acetic acid, which is a preferred compound for methanogenic bacteria, was found to account for 33% of the total organic carbon. PMID:26164636

  4. Catalytic properties of Co3O4 nanoparticles for rechargeable Li/air batteries

    OpenAIRE

    Kim, Kwan Su; Park, Yong Joon

    2012-01-01

    Three types of Co3O4 nanoparticles are synthesized and characterized as a catalyst for the air electrode of a Li/air battery. The shape and size of the nanoparticles are observed using scanning electron microscopy and transmission electron microscopy analyses. The formation of the Co3O4 phase is confirmed by X-ray diffraction. The electrochemical property of the air electrodes containing Co3O4 nanoparticles is significantly associated with the shape and size of the nanoparticles. It appears t...

  5. Toluene removal from waste air stream by the catalytic ozonation process with MgO/GAC composite as catalyst.

    Science.gov (United States)

    Rezaei, Fatemeh; Moussavi, Gholamreza; Bakhtiari, Alireza Riyahi; Yamini, Yadollah

    2016-04-01

    This paper investigates the catalytic potential of MgO/GAC composite for toluene elimination from waste air in the catalytic ozonation process (COP). The MgO/GAC composite was a micro-porous material with the BET surface area of 1082m(2)/g. Different functional groups including aromatic CC, saturated CO of anhydrates, hydroxyl groups and SH bond of thiols were identified on the surface of MgO/GAC. Effects of residence time (0.5-4s), inlet toluene concentration (100-400ppmv) and bed temperature (25-100°C) were investigated on degradation of toluene in COP. Impregnation of GAC with MgO increased the breakthrough time and removal capacity by 73.9% and 64.6%, respectively, at the optimal conditions. The catalytic potential of the GAC and MgO/GAC for toluene degradation was 11.1% and 90.6%, respectively, at the optimum condition. The highest removal capacity using MgO/GAC (297.9gtoulene/gMgO/GAC) was attained at 100°C, whereas the highest removal capacity of GAC (128.5mgtoulene/gGAC) was obtained at 25°C. Major by-products of the toluene removal in COP with GAC were Formic acid, benzaldehyde, O-nitro-p-cresol and methyl di-phenyl-methane. MgO/GAC could greatly catalyze the decomposition of toluene in COPand formic acid was the main compound desorbed from the catalyst. Accordingly, the MgO/GAC is an efficient material to catalyze the ozonation of hydrocarbon vapors. PMID:26784452

  6. The Influence of Slight Protuberances in a Micro-Tube Reactor on Methane/Moist Air Catalytic Combustion

    Directory of Open Access Journals (Sweden)

    Ruirui Wang

    2016-05-01

    Full Text Available The combustion characteristics of methane/moist air in micro-tube reactors with different numbers and shapes of inner wall protuberances are investigated in this paper. The micro-reactor with one rectangular protuberance (six different sizes was studied firstly, and it is shown that reactions near the protuberance are mainly controlled by diffusion, which has little effect on the outlet temperature and methane conversion rate. The formation of cavities and recirculation zones in the vicinity of protuberances leads to a significant increase of the Arrhenius reaction rate of CH4 and gas velocity. Next, among the six different simulated conditions (0–5 rectangular protuberances, the micro-tube reactor with five rectangular protuberances shows the highest methane conversion rate. Finally, the effect of protuberance shape on methane/moist air catalytic combustion is confirmed, and it is found that the protuberance shape has a greater influence on methane conversion rate than the number of protuberances. The methane conversion rate in the micro-tube decreases progressively in the following order: five triangular slight protuberances > five rectangular protuberances > five trapezoidal protuberances > smooth tube. In all tests of methane/moist air combustion conditions, the micro-tube with five triangular protuberances has the peak efficiency and is therefore recommended for high efficiency reactors.

  7. 干球温度和湿球温度对湿式空冷器冷却能力的影响%Impact of dry-bulb and wet-bulb temperature on cooling capacity of wet-type air cooler

    Institute of Scientific and Technical Information of China (English)

    任志强

    2016-01-01

    依据湿式空冷器测试标准建立了性能测试试验台, 试验研究了干球温度和湿球温度对湿式空冷器冷却能力的影响. 结果表明, 当湿球温度一定时, 干球温度对湿式空冷器的影响较大; 因此, 设计湿式空冷器时不能只考虑湿球温度, 不考虑干球温度. 同时分析了湿球温度与湿空冷管程进水温度的温差对湿式空冷器冷却能力的影响.%According to the test standard of wet-type air cooler, a performance test-bed was established to study the impact of dry-bulb and wet-bulb temperature on cooling capacity of wet-type air cooler. The results showed that, when the wet-bulb temperature was fixed, dry-bulb temperature had appreciably effect on the cool-ing capacity of the wet-type air cooler; the consideration of the wet-type air cooler design should include not only wet-bulb temperature, but also dry-bulb temperature. The influence of the temperature difference between wet-bulb and inlet water of wet air cooled tube on cooling capacity of wet-type air cooler were also analyzed.

  8. Catalytic activity trends of oxygen reduction reaction for nonaqueous Li-air batteries.

    Science.gov (United States)

    Lu, Yi-Chun; Gasteiger, Hubert A; Shao-Horn, Yang

    2011-11-30

    We report the intrinsic oxygen reduction reaction (ORR) activity of polycrystalline palladium, platinum, ruthenium, gold, and glassy carbon surfaces in 0.1 M LiClO(4) 1,2-dimethoxyethane via rotating disk electrode measurements. The nonaqueous Li(+)-ORR activity of these surfaces primarily correlates to oxygen adsorption energy, forming a "volcano-type" trend. The activity trend found on the polycrystalline surfaces was in good agreement with the trend in the discharge voltage of Li-O(2) cells catalyzed by nanoparticle catalysts. Our findings provide insights into Li(+)-ORR mechanisms in nonaqueous media and design of efficient air electrodes for Li-air battery applications. PMID:22044022

  9. Catalytic Reductive Degradation of Methyl Orange Using Air Resilient Copper Nanostructures

    Directory of Open Access Journals (Sweden)

    Razium Ali Soomro

    2015-01-01

    Full Text Available The study describes the application of oxidation resistant copper nanostructures as an efficient heterogeneous catalyst for the treatment of organic dye containing waste waters. Copper nanostructures were synthesized in an aqueous environment using modified surfactant assisted chemical reduction route. The synthesized nanostructures have been characterized by UV-Vis, Fourier transform infrared spectroscopy FTIR spectroscopy, Atomic force microscopy (AFM, Scanning Electron Microscopy (SEM, and X-ray diffractometry (XRD. These surfactant capped Cu nanostructures have been used as a heterogeneous catalyst for the comparative reductive degradation of methyl orange (MO in the presence of sodium borohydride (NaBH4 used as a potential reductant. Copper nanoparticles (Cu NPs were found to be more efficient compared to copper nanorods (Cu NRds with the degradation reaction obeying pseudofirst order reaction kinetics. Shape dependent catalytic efficiency was further evaluated from activation energy (EA of reductive degradation reaction. The more efficient Cu NPs were further employed for reductive degradation of real waste water samples containing dyes collected from the drain of different local textile industries situated in Hyderabad region, Pakistan.

  10. Effect of inlet temperature on the performance of a catalytic reactor. [air pollution control

    Science.gov (United States)

    Anderson, D. N.

    1978-01-01

    A 12 cm diameter by 15 cm long catalytic reactor was tested with No. 2 diesel fuel in a combustion test rig at inlet temperatures of 700, 800, 900, and 1000 K. Other test conditions included pressures of 3 and 6 x 10 to the 5th power Pa, reference velocities of 10, 15, and 20 m/s, and adiabatic combustion temperatures in the range 1100 to 1400 K. The combustion efficiency was calculated from measurements of carbon monoxide and unburned hydrocarbon emissions. Nitrogen oxide emissions and reactor pressure drop were also measured. At a reference velocity of 10 m/s, the CO and unburned hydrocarbons emissions, and, therefore, the combustion efficiency, were independent of inlet temperature. At an inlet temperature of 1000 K, they were independent of reference velocity. Nitrogen oxides emissions resulted from conversion of the small amount (135 ppm) of fuel-bound nitrogen in the fuel. Up to 90 percent conversion was observed with no apparent effect of any of the test variables. For typical gas turbine operating conditions, all three pollutants were below levels which would permit the most stringent proposed automotive emissions standards to be met.

  11. Combustion of CH4/H2/air mixtures in catalytic microreactors.

    Science.gov (United States)

    Specchia, Stefania; Vella, Luigi D; Burelli, Sara; Saracco, Guido; Specchia, Vito

    2009-03-23

    The combustion of CH(4)/H(2)/HC mixtures in a very small space represents an alternative, innovative way to produce thermal/electrical energy. Pd/NiCrO(4) catalysts are lined on SiC monoliths via in situ solution combustion synthesis (SCS), and the monoliths are then tested by feeding CH(4), H(2), and lean CH(4)/H(2) mixtures into a lab-scale test rig at an output thermal power of 7.6 MW(th) m(-3). In all cases, the combustion temperature shifts to values lower than those observed in non-catalytic combustion. When the power density is kept constant (by adding H(2) to the gas mixture), the value of CH(4)-T(50) (the half-conversion temperature of CH(4)) decreases relative to that of pure CH(4), and the slope of the conversion curve becomes steeper. The higher the H(2) concentration is, the higher the reactivity of the mixture towards CH(4) oxidation-probably due to a higher production of H(2) reactive radicals (OH).

  12. 新风湿球温度在组合式空调机中的应用%Application of Fresh Air Wet Bulb Temperature in Combined Air Conditioner

    Institute of Scientific and Technical Information of China (English)

    刘晓鹏

    2016-01-01

    提出了组合式空调机运行工况判断标准,论述了新风湿球温度在春季、秋季及过渡季节的应用,讨论了湿球温度与送风温度的关系,分析了湿球温度变化趋势影响因素,对拓宽管理人员思路和提高运行人员操作水平有很好的启发和借鉴作用,可有效提升管理水平,降低空调运行能耗。%This paper presents the application of fresh air wet bulb temperature in spring, autumn and transition season to determine the operating conditions of the combined air conditioner. Then it discusses the relationship between wet bulb tem-perature and air supply temperature, analyzes the influencing factors of wet bulb temperature. It has a good reference for broadening the mind of management and improving the operational level of operators. Also it can effectively improve the management level and reduce the energy consumption of air conditioning.

  13. Understanding the wetting properties of nanostructured selenium coatings: the role of nanostructured surface roughness and air-pocket formation

    Directory of Open Access Journals (Sweden)

    Tran PA

    2013-05-01

    Full Text Available Phong A Tran,1,2 Thomas J Webster31Department of Chemical and Biomolecular Engineering, University of Melbourne, Melbourne, VIC, Australia; 2The Particulate Fluid Processing Centre, University of Melbourne, Melbourne, VIC, Australia; 3Department of Chemical Engineering and Program in Bioengineering, Northeastern University, Boston, MA, USAAbstract: Wetting properties of biomaterials, in particular nanomaterials, play an important role, as these influence interactions with biological elements, such as proteins, bacteria, and cells. In this study, the wetting phenomenon of titanium substrates coated with selenium nanoparticles was studied using experimental and mathematical modeling tools. Importantly, these selenium-coated titanium substrates were previously reported to increase select protein adsorption (such as vitronectin and fibronectin, to decrease bacteria growth, and increase bone cell growth. Increased selenium nanoparticle coating density resulted in higher contact angles but remained within the hydrophilic regime. This trend was found in disagreement with the Wenzel model, which is widely used to understand the wetting properties of rough surfaces. The trend also did not fit well with the Cassie–Baxter model, which was developed to understand the wetting properties of composite surfaces. A modified wetting model was thus proposed in this study, to understand the contributing factors of material properties to the hydrophilicity/hydrophobicity of these nanostructured selenium-coated surfaces. The analysis and model created in this study can be useful in designing and/or understanding the wetting behavior of numerous biomedical materials and in turn, biological events (such as protein adsorption as well as bacteria and mammalian cell functions.Keywords: hydrophilicity, hydrophobicity, Wenzel model, Cassie–Baxter model, free energy, implant material, proteins, cells, bacteria

  14. Numerical study of methanol–steam reforming and methanol–air catalytic combustion in annulus reactors for hydrogen production

    International Nuclear Information System (INIS)

    Highlights: ► Performance of mini-scale integrated annulus reactors for hydrogen production. ► Flow rates fed to combustor and reformer control the reactor performance. ► Optimum performance is found from balance of flow rates to combustor and reformer. ► Better performance can be found when shell side is designed as combustor. -- Abstract: This study presents the numerical simulation on the performance of mini-scale reactors for hydrogen production coupled with liquid methanol/water vaporizer, methanol/steam reformer, and methanol/air catalytic combustor. These reactors are designed similar to tube-and-shell heat exchangers. The combustor for heat supply is arranged as the tube or shell side. Based on the obtained results, the methanol/air flow rate through the combustor (in terms of gas hourly space velocity of combustor, GHSV-C) and the methanol/water feed rate to the reformer (in terms of gas hourly space velocity of reformer, GHSV-R) control the reactor performance. With higher GHSV-C and lower GHSV-R, higher methanol conversion can be achieved because of higher reaction temperature. However, hydrogen yield is reduced and the carbon monoxide concentration is increased due to the reversed water gas shift reaction. Optimum reactor performance is found using the balance between GHSV-C and GHSV-R. Because of more effective heat transfer characteristics in the vaporizer, it is found that the reactor with combustor arranged as the shell side has better performance compared with the reactor design having the combustor as the tube side under the same operating conditions.

  15. Catalytic Partial Oxidation of Methane with Air to Syngas in a Pilot-Plant-Scale Spouted Bed Reactor

    Institute of Scientific and Technical Information of China (English)

    魏伟胜; 徐建; 方大伟; 鲍晓军

    2003-01-01

    On the basis of hydrodynamic and scaling-up studies, a pilot-plant-scale thermal spouted bed reactor (50 mm in ID and 1500 mm in height) was designed and fabricated by scaling-down cold simulators. It was tested for making syngas via catalytic partial oxidation (CPO) of methane by air. The effects of various operating conditions such as operating pressure and temperature, feed composition, and gas flowrate etc. on the CPO process were investigated. CH4 conversion of 92.20% and selectivity of 92.3% and 83.30/0 to CO and H2, respectively, were achieved at the pressure of 2.1 MPa. It was found that when the spouted bed reactor was operated within the stable spouting flow regime, the temperature profiles along the bed axis were much more uniform than those operated within the fixed-bed regime. The CH4 conversion and syngas selectivity were found to be close to thermodynamic equilibrium limits. The results of the present investigation showed that spouted bed could be considered as a potential type of chemical reactor for the CPO process of methane.

  16. DRY/WET PERFORMANCE OF A PLATE-FIN AIR COOLED HEAT EXCHANGER WITH CONTINUOUS CORRUGATED FINS

    Science.gov (United States)

    The report describes work to (1) determine experimentally the performance and operating characteristics of a plate-fin heat exchanger during dry/wet or 'deluge' operation and (2) continue developing the deluge heat/mass transfer model. This work supports the improvement of power ...

  17. A review of induction and attachment times of wetting thin films between air bubbles and particles and its relevance in the separation of particles by flotation.

    Science.gov (United States)

    Albijanic, Boris; Ozdemir, Orhan; Nguyen, Anh V; Bradshaw, Dee

    2010-08-11

    Bubble-particle attachment in water is critical to the separation of particles by flotation which is widely used in the recovery of valuable minerals, the deinking of wastepaper, the water treatment and the oil recovery from tar sands. It involves the thinning and rupture of wetting thin films, and the expansion and relaxation of the gas-liquid-solid contact lines. The time scale of the first two processes is referred to as the induction time, whereas the time scale of the attachment involving all the processes is called the attachment time. This paper reviews the experimental studies into the induction and attachment times between minerals and air bubbles, and between oil droplets and air bubbles. It also focuses on the experimental investigations and mathematical modelling of elementary processes of the wetting film thinning and rupture, and the three-phase contact line expansion relevant to flotation. It was confirmed that the time parameters, obtained by various authors, are sensitive enough to show changes in both flotation surface chemistry and physical properties of solid surfaces of pure minerals. These findings should be extended to other systems. It is proposed that measurements of the bubble-particle attachment can be used to interpret changes in flotation behaviour or, in conjunction with other factors, such as particle size and gas dispersion, to predict flotation performance. PMID:20478547

  18. 1 - Aromatization of n-hexane and natural gasoline over ZSM-5 zeolite, 2- Wet catalytic oxidation of phenol on fixed bed of active carbon; 1 - Aromatisation de n-hexane et d'essence sur zeolithe ZSM-5, 2 - Oxydation catalytique en voie humide du phenol sur charbon actif

    Energy Technology Data Exchange (ETDEWEB)

    Suwanprasop, S.

    2005-04-15

    I - The production of aromatic hydrocarbons from n-hexane and natural gasoline over Pd loaded ZSM-5 zeolite in a tubular reactor was achieved under the suitable conditions at 400 deg. C, and 0.4 ml/min reactant feeding rate, employing ZSM-5 (0.5% Pd content) as a catalyst. Under these conditions, n-hexane and natural gasoline conversions were found to be 99.7% and 94.3%, respectively (with respective aromatic selectivity of 92.3% and 92.6%). II - Wet catalytic air oxidation of phenol over a commercial active carbon was studied in a three phase fixed bed reactor under mild temperature and oxygen partial pressure. Exit phenol concentration, COD, and intermediates were analysed. Oxidation of phenol was significantly improved when increasing operating temperature, oxygen partial pressure, and liquid space time, while up or down flow modes had only marginal effect. A complete model involving intrinsic kinetics and all mass transfer limitations gave convenient reactor simulation. (author)

  19. Total catalytic wet oxidation of phenol and its chlorinated derivates with MnO{sub 2}/CeO{sub 2} catalyst in a slurry

    Energy Technology Data Exchange (ETDEWEB)

    Luna, A.J. [Instituto Nacional de Propriedade Industrial (INPI), Rio de Janeiro, RJ (Brazil)], e-mail: airtonj@inpi.gov.br; Rojas, L.O.A.; Sousa, J.F. de [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. of Chemical Engineering; Melo, D.M.A. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. of Chemistry; Benachour, M. [Universidade Federal de Pernambuco (UFPE)Recife, PE (Brazil). Dept. of Chemical Engineering

    2009-07-15

    In the present work, a synthetic effluent of phenol was treated by means of a total oxidation process - Catalyzed Wet Oxidation (CWO). A mixed oxide of Mn-Ce (7:3), the catalyst, was synthesized by co-precipitation from an aqueous solution of MnCl{sub 2} and CeCl{sub 3} in a basic medium. The mixed oxide, MnO{sub 2}/CeO{sub 2}, was characterized and used in the oxidation of phenol in a slurry reactor in the temperature range of 80-130 deg C and pressure of 2.04-4.76 MPa. A phenol solution containing 2.4-dichlorophenol and 2.4- dichlorophenoxyacetic acid was also degraded with good results. A lumped kinetic model, with two parallel reaction steps, fits precisely with the integrated equation and the experimental data. The kinetic parameters obtained are in agreement with the Arrhenius equation. The activation energies were determined to be 38.4 for the total oxidation and 53.4 kJ/mol for the organic acids formed. (author)

  20. Total catalytic wet oxidation of phenol and its chlorinated derivates with MnO2/CeO2 catalyst in a slurry

    Directory of Open Access Journals (Sweden)

    A. J. Luna

    2009-09-01

    Full Text Available In the present work, a synthetic effluent of phenol was treated by means of a total oxidation process-Catalyzed Wet Oxidation (CWO. A mixed oxide of Mn-Ce (7:3, the catalyst, was synthesized by co-precipitation from an aqueous solution of MnCl2 and CeCl3 in a basic medium. The mixed oxide, MnO2/CeO2, was characterized and used in the oxidation of phenol in a slurry reactor in the temperature range of 80-130ºC and pressure of 2.04-4.76 MPa. A phenol solution containing 2.4-dichlorophenol and 2.4-dichlorophenoxyacetic acid was also degraded with good results. A lumped kinetic model, with two parallel reaction steps, fits precisely with the integrated equation and the experimental data. The kinetic parameters obtained are in agreement with the Arrhenius equation. The activation energies were determined to be 38.4 for the total oxidation and 53.4 kJ/mol for the organic acids formed.

  1. 催化湿式过氧化氢氧化预处理有机磷农药废水的研究%Study on catalytic wet hydrogen peroxide oxidation for the pretreatment of organophosphorus pesticide wastewater

    Institute of Scientific and Technical Information of China (English)

    陈春燕

    2015-01-01

    以自制Fe2O3-CeO2/γ-Al2O3为催化剂,采用催化湿式过氧化氢氧化法(CWPO)预处理有机磷农药废水,通过单因素和正交试验研究了过氧化氢投加量、起始pH、反应温度和反应时间对COD的去除效果及影响规律。结果表明,反应最优条件为H2O2投加量2 mL、起始pH=5、反应温度80℃、反应时间40 min,在此条件下COD的去除率可达85.8%,可生化性提高到B/C=0.43。运用一级动力学模型和Arrhenius经验公式,建立了催化湿式过氧化氢氧化降解COD的动力学方程。%With self-made Fe2O3-CeO2/γ-Al2O3 as catalyst,the phosphate pesticide wastewater has been pretreated by catalytic wet peroxide oxidation(CWPO) process. The removing effect and influencing rules of the factors including dosage of H2O2,initial pH value,reaction temperature,and reaction time on the removing rate of COD are investigated through single factor experiments and orthogonal tests. The results show that the optimal COD removing efficiency is more than 85.8% and biodegradability of wastewater can be up to B/C=0.43,under the following conditions:the dosage of H2O2 is 2 mL,pH value 5,reaction temperature 80℃and reaction time 40 min. The kinetics equation of catalytic wet peroxide oxidation of COD degradation has been established by using the first-order kinetics model and Arrhenius empirical formula.

  2. APPLICATION OF WET TYPE SMOKE DESULFURIZATION DEDUSTING TECHNOLOGY IN TMP CATALYTIC AND CRACKING UNIT%湿式烟气脱硫除尘技术在TMP催化裂化装置的应用

    Institute of Scientific and Technical Information of China (English)

    高传成; 马传波; 王付印

    2014-01-01

    A new smoke desulfurization dedusting unit by adopting sodium magnesium wet type desulfurization technology was built on 0.3 Mt/a TMP catalytic and cracking plant of Hengyuan Petrochemical Company .The industrial running results showed that the new built des-ulfurization dedusting unit had good operational flexibility and economic stability .Minimum con-tent of SO2 in the purified smoke could reach 3 mg/m3 and the removal rate was 99.9%.The av-erage dust content of the purified smoke was 16.3 mg/m3 and preceded the design value .Each control index on the discharged exhaust gas of the TMP catalytic and cracking unit after reforma-tion met the discharge standard requirement , which realized high efficient and continuous run-ning.%恒源石化在0.3 Mt/a的 TMP 催化裂化装置采用钠镁法湿式烟气脱硫技术,新建1套烟气脱硫除尘装置。工业运行结果表明,钠镁法烟气脱硫除尘装置具有良好的操作弹性,运行经济可靠。净化后烟气中的SO2浓度最低能达到3 mg/m3,SO2脱除率达到99.9%,净化烟气平均粉尘含量16.3 mg/m3,优于设计值。实现了高效连续运行,可控外排废气中的各项指标满足排放要求。

  3. Oil sands development and its impact on atmospheric wet deposition of air pollutants to the Athabasca Oil Sands Region, Alberta, Canada.

    Science.gov (United States)

    Lynam, Mary M; Dvonch, J Timothy; Barres, James A; Morishita, Masako; Legge, Allan; Percy, Kevin

    2015-11-01

    Characterization of air pollutant deposition resulting from Athabasca oil sands development is necessary to assess risk to humans and the environment. To investigate this we collected event-based wet deposition during a pilot study in 2010-2012 at the AMS 6 site 30 km from the nearest upgrading facility in Fort McMurray, AB, Canada. Sulfate, nitrate and ammonium deposition was (kg/ha) 1.96, 1.60 and 1.03, respectively. Trace element pollutant deposition ranged from 2 × 10(-5) - 0.79 and exhibited the trend Hg oil sands development, urban activities and forest fires were deposited. High deposition of the elements Sr, Mn, Fe and Mg which are tracers for soil and crustal dust implies land-clearing, mining and hauling emissions greatly impacted surrounding human settlements and ecosystems. PMID:26277649

  4. Control of oil-wetting on technical textiles by means of photo-chemical surface modification and its relevance to the performance of compressed air filters

    Energy Technology Data Exchange (ETDEWEB)

    Bahners, Thomas, E-mail: bahners@dtnw.de [Deutsches Textilforschungszentrum Nord-West gGmbH (DTNW), Adlerstr. 1, 47798 Krefeld (Germany); Mölter-Siemens, Wolfgang; Haep, Stefan [Institut für Energie- und Umwelttechnik e.V. (IUTA), Bliersheimer Str. 60, 47229 Duisburg (Germany); Gutmann, Jochen S. [Deutsches Textilforschungszentrum Nord-West gGmbH (DTNW), Adlerstr. 1, 47798 Krefeld (Germany); Universität Duisburg-Essen, Physikalische Chemie and CENIDE, Universitätsstr. 2, 45141 Essen (Germany)

    2014-09-15

    Highlights: • The oil repellence of textile fabrics was increased following the Wenzel concept. • Fiber surfaces were micro-roughened by means of pulsed UV laser irradiation. • Subsequent UV-induced grafting yielded pronounced oil repellence. • The grafting process conserved the delicate topography of the fiber surfaces. • The modified fabrics showed favorable drainage behavior in oil droplet separation. - Abstract: A two-step process comprising a surface roughening step by excimer laser irradiation and a post-treatment by photo-grafting to decrease the surface free energy was employed to increase the oil repellence of technical fabrics made of poly(ethylene terephthalate) (PET). The modification was designed to improve the performance of multi-layer filters for compressed air filtration, in which the fabrics served to remove, i.e. drain, oil separated from the air stream. In detail, the fibers surfaces were roughened by applying several laser pulses at a wavelength of 248 nm and subsequently photo-grafted with 1H,1H,2H,2H-perfluoro-decyl acrylate (PPFDA). The oil wetting behavior was increased by the treatments from full wetting on the as-received fabrics to highly repellent with oil contact angles of (131 ± 7)°. On surfaces in the latter state, oil droplets did not spread or penetrate even after one day. The grafting of PPFDA alone without any surface roughening yielded an oil contact angle of (97 ± 11)°. However, the droplet completely penetrated the fabric over a period of one day. The drainage performance was characterized by recording the pressure drop over a two-layer model filter as a function of time. The results proved the potential of the treatment, which reduced the flow resistance after 1-h operation by approximately 25%.

  5. Precipitation of antimony from the solution of sodium thioantimonite by air oxidation in the presence of catalytic agents

    Institute of Scientific and Technical Information of China (English)

    杨天足; 赖琼琳; 唐建军; 楚广

    2002-01-01

    The behavior of antimony oxidation in the solution of sodium thioantimonite was studied in the presence of catalytic agents. The catalytic effects of the respective addition of cupric sulfate, sodium tartrate, potassium permanganate, phenol, 1,2-dihydroxybenzene and their combination on the oxidation of sodium thioantimonite were investigated. A pilot test was carried out. The results show that the respective use of sodium tartrate, cupric sulfate, potassium permanganate, phenol and 1,2-dihydroxybenzene have little catalytic effect on the oxidation of sodium thioantimonite. However there exists obvious catalytic oxidation by the combination of 0.25 g/L 1,2-dihydroxybenzene, 0.5 g/L potassium permanganate and 1.0 g/L phenol. Moreover, high blast intensity, the increase of temperature and NaOH concentration favor the oxidation of antimony. The oxidation process of antimony has such advantages as quick reaction and low operation costs. The results of the pilot test are consistent with those of laboratory experiments.

  6. Wet Oxidation of PVA-Containing Desizing Wastewater

    Institute of Scientific and Technical Information of China (English)

    雷乐成; 汪大翬

    2000-01-01

    Polyvinyl alcohol (PVA)-containing desizing wastewater was treated by various wet oxidation methods.Parameters such as reaction temperature, initial solution pH, and the dosage of H2O2 were investigated in terms of chemical oxygen demand (CODcr) and total organic carbon (TOC) removal rate. Up to 90% of the initial CODcr was removed by wet air oxidation(WAO) at 270℃ with stoichiometric oxygen supply, while at temperature of 200℃, the CODcr removal rate was found to be 80%. Similar results were obtained by Promoted WAO (PWAO) and wet peroxide oxidation(WPO) at a lower temperature of 150℃. Reaction temperature was found to have a significant effect on the oxidation performance for all the methods. Initial solution pH was observed to play a significant role in PWAO and WPO where H2O2 was employed. Comparison of WAO, CWAO(catalytic wet air oxidation), PWAO and WPO shows that the rate of CODcr removal increases in the order: WAO, CWAO, PWAO and WPO.

  7. TASK TECHNICAL AND QUALITY ASSURANCE PLAN FOR OUT-OF-TANK DESTRUCTION OF TETRAPHENYLBORATE VIA WET AIR OXIDATION TECHNOLOGY: PHASE I - BENCH SCALE TESTS

    Energy Technology Data Exchange (ETDEWEB)

    Adu-Wusu, K

    2006-03-31

    Tank 48H return to service is critical to the processing of high level waste (HLW) at Savannah River Site (SRS). Liquid Waste Disposition (LWD) management has the goal of returning Tank 48H to routine service by January 2010 or as soon as practical. Tank 48H currently holds legacy material containing organic tetraphenylborate (TPB) compounds from the operation of the In-Tank Precipitation process. This material is not compatible with the waste treatment facilities at SRS and must be removed or undergo treatment to destroy the organic compounds before the tank can be returned to Tank Farm service. Tank 48H currently contains {approx}240,000 gallons of alkaline slurry with about 2 wt % potassium and cesium tetraphenylborate (KTPB and CsTPB). The main radioactive component in Tank 48H is {sup 137}Cs. The waste also contains {approx}0.15 wt % Monosodium Titanate (MST) which has adsorbed {sup 90}Sr, U, and Pu isotopes. A System Engineering Evaluation of technologies/ideas for the treatment of TPB identified Wet Air Oxidation (WAO) as a leading alternative technology to the baseline aggregation approach. Over 75 technologies/ideas were evaluated overall. Forty-one technologies/ideas passed the initial screening evaluation. The 41 technologies/ideas were then combined to 16 complete solutions for the disposition of TPB and evaluated in detail. Wet Air Oxidation (WAO) is an aqueous phase process in which soluble or suspended waste components are oxidized using molecular oxygen contained in air. The process operates at elevated temperatures and pressures ranging from 150 to 320 C and 7 to 210 atmospheres, respectively. The products of the reaction are CO{sub 2}, H{sub 2}O, and low molecular weight oxygenated organics (e.g. acetate, oxalate). The basic flow scheme for a typical WAO system is as follows. The waste solution or slurry is pumped through a high-pressure feed pump. An air stream containing sufficient oxygen to meet the oxygen requirements of the waste stream is

  8. Experimental Study on Emission Control of Premixed Catalytic Combustion of Natural Gas Using Preheated Air%使用加热空气的预混天然气催化燃烧的实验研究

    Institute of Scientific and Technical Information of China (English)

    许考; 刘中良; 何洪; 程水源; 马重芳

    2007-01-01

    In this paper the premixed catalytic combustion emissions such as CO, unburned hydrocarbon (UHC),NOx and the temperature distribution in the catalytic monolith with ultra low concentration of Pd were studied.Three types of monoliths were used for experiments and the temperature of preheated air was respectively 50℃,100℃ and 200℃. The results showed that preheated air made radial temperature in the catalytic monolith uniform which helped to avoid local hot spots so as to decrease NOx emission. The experiment also proved that the shorter monolith showed much better catalytic combustion performance than longer one and the temperature at the exit of the shorter monolith was relatively lower. On the contrary, the temperature was higher in the longer monolith and the lethal NOx emission was slightly increased.

  9. Hydrogen peroxide detection in wet air with a Prussian Blue based solid salt bridged three electrode system.

    Science.gov (United States)

    Komkova, Maria A; Karyakina, Elena E; Marken, Frank; Karyakin, Arkady A

    2013-03-01

    We report on a novel electroanalytical system for hydrogen peroxide (H2O2) detection in humidity or droplets of aerosol, formed by air bubbling through a washing chamber; the resulting flow mimics the exhaled human breath. The system is based on a planar three-electrode structure (with a Prussian Blue based H2O2 transducer modified working electrode) bridged by a solid salt-saturated filament material (filter paper, cotton textile). Respective to the hydrogen peroxide content in the washing valve, the response of the aerosol-sensing system is linear in the concentration range of 0.1-10 μM, which overlaps the generally accepted H2O2 content in exhaled breath condensate (EBC), with the sensitivity of 8 A M(-1) cm(-2). The response to the upper limit of the calibration range is stable for more than 50 injection cycles recorded within 3 days. Both the stability and the suitable calibration range allow one to consider the reported aerosol-sensing system as a prototype for a simple (avoiding intermediate EBC collection) noninvasive diagnostic tool for pulmonary patients. PMID:23374034

  10. Wetting transitions

    International Nuclear Information System (INIS)

    When a liquid droplet is put onto a surface, two situations distinguishable by the contact angle may result. If the contact angle is zero, the droplet spreads across the surface, a situation referred to as complete wetting. On the other hand, if the contact angle is between 0 deg. and 180 deg., the droplet does not spread, a situation called partial wetting. A wetting transition is a surface phase transition from partial wetting to complete wetting. We review the key experimental findings on this transition, together with simple theoretical models that account for the experiments. The wetting transition is generally first order (discontinuous), implying a discontinuity in the first derivative of the surface free energy. In this case, if one measures the thickness of the adsorbed film beside the droplet, at the wetting transition a discontinuous jump in film thickness occurs from a microscopically thin to a thick film. We show that this can lead to the observation of metastable surface states and an accompanying hysteresis. The observed hysteresis poses, in turn, a number of questions concerning the nucleation of wetting films that we also consider here. In addition, we consider the equilibrium wetting film thickness that results from a competition between the long-range van der Waals forces and gravity. Finally, the first-order character of the wetting transition can lead to a similar transition even when the phase that does the wetting is not (yet) stable in the bulk. For such prewetting transitions, a discontinuous thin-to-thick film transition occurs off bulk coexistence. We show that, for the large variety of systems for which prewetting transitions have been observed, the behaviour is surprisingly uniform, and can be mapped onto a simple generic phase diagram. The second part of the review deals with the exceptions to the first-order nature of the wetting transition. Two different types of continuous or critical wetting transition have been reported, for which

  11. Regional-scale impacts of Phase 1 of the Clean Air Act Amendments in the USA: the relation between emissions and concentrations, both wet and dry

    International Nuclear Information System (INIS)

    A comparison of data records in the 1990s, both before (1991-1994) and after (1995-1997) implementation of Phase I of the Clean Air Act Amendments (CAAA) of 1990 for the eastern US, shows a significant reduction in SO2 emissions for most states, except for Texas, North Carolina, Illinois, Florida, and Alabama. However, of the major NOx emitting states, only two eastern states (New York and Pennsylvania) show significant declines in NOx. A pattern of large declines in SO2 emissions (>20%) after CAAA implementation, and large declines in precipitation SO42- and H+, as well as air concentrations of SO2 and SO42- (components of dry deposition), exists for most regions of the eastern US. In most cases, the emission/concentration relations are close to 1:1 when the source region based on 15-h back trajectories is used for the New England region, and source regions based on 9-h back trajectories are used for the six other eastern US regions that were studied. The southern Appalachian Mountain region, an acid-sensitive area receiving high levels of acidic deposition, has not seen an appreciable improvement in precipitation acidity. This area has also shown the least improvement in wet and dry sulfur concentrations, of the areas examined. Precipitation base cations (Ca2+ and Mg2+) show a pattern of either increasing or level concentrations when comparing 1990-1994 to 1995-1998 data, for six of the seven regions examined. Ammonium concentrations have generally changed 15%. (Author)

  12. Oil sands development and its impact on atmospheric wet deposition of air pollutants to the Athabasca Oil Sands Region, Alberta, Canada.

    Science.gov (United States)

    Lynam, Mary M; Dvonch, J Timothy; Barres, James A; Morishita, Masako; Legge, Allan; Percy, Kevin

    2015-11-01

    Characterization of air pollutant deposition resulting from Athabasca oil sands development is necessary to assess risk to humans and the environment. To investigate this we collected event-based wet deposition during a pilot study in 2010-2012 at the AMS 6 site 30 km from the nearest upgrading facility in Fort McMurray, AB, Canada. Sulfate, nitrate and ammonium deposition was (kg/ha) 1.96, 1.60 and 1.03, respectively. Trace element pollutant deposition ranged from 2 × 10(-5) - 0.79 and exhibited the trend Hg < Se < As < Cd < Pb < Cu < Zn < S. Crustal element deposition ranged from 1.4 × 10(-4) - 0.46 and had the trend: La < Ce < Sr < Mn < Al < Fe < Mg. S, Se and Hg demonstrated highest median enrichment factors (130-2020) suggesting emissions from oil sands development, urban activities and forest fires were deposited. High deposition of the elements Sr, Mn, Fe and Mg which are tracers for soil and crustal dust implies land-clearing, mining and hauling emissions greatly impacted surrounding human settlements and ecosystems.

  13. DEVELOPMENT OF CONSTRUCTION OF A CATALYTIC REACTOR FOR METHANE OXIDISING IN VENTILATION AIR IN COAL MINES AND THE RESEARCH ON INTEGRATED “HEAT PIPE” RECUPERATOR

    Directory of Open Access Journals (Sweden)

    Lech Hys

    2013-04-01

    Full Text Available The article presents the analysis whose result is the selection of appropriate design and construction of a monolithic CMR reactor intended for oxidising methane from ventilation air in coal mines. The description of “heat-pipe” recuperator cooperating with the reactor was also presented. The research was mainly aimed at verifying the compliance with the work of autothermity premise obtained by the return of part of heat from catalytic reaction. The result of research was to define the range volumetric fume expense ensuring autothermity and the definition of maximum recuperator efficiency. The range of volumetric expense was 18–25 m3/h and maximum value of efficiency coefficient was η = 0.50 for the volumetric expense of 18 m3/h.

  14. Recovery and characterization of Balanites aegyptiaca Del. kernel proteins. Effect of defatting, air classification, wet sieving and aqueous ethanol treatment on solubility, digestibility, amino acid composition and sapogenin content.

    Science.gov (United States)

    Mohamed, A M; Wolf, W; Spiess, W E

    2000-02-01

    In order to find alternative protein sources in African regions where protein deficiency in nutrition is prevailing, solubility, in-vitro digestibility, amino acid composition and chemical score of Balanites aegyptiaca Del. kernel proteins were investigated as a function of different processing steps including defatting, air classification, wet sieving and aqueous ethanol treatment. Air classification delivered a fine fraction of 58.1% of the total protein. Applying a wet sieving process, a protein concentrate of 72.9% protein content was achieved but the recovery was very low (35.6%). However, in case of isoelectric precipitation followed by aqueous ethanol treatment both protein content (78.2%) and recovery (53.7%) were high. Data concerning the chemical score revealed, that lysine content of the defatted kernel flour amounted to 74.2% of the recommended FAO/WHO standard level. In-vitro protein digestibility was found to be higher than of legume proteins. The digestible protein of the full fat flour, defatted flour, air classified and wet sieved fine fractions and protein concentrate were 91.9, 93.7, 82.0, 86.4 and 94.2%, respectively. The sapogenin content per 100 g protein of the investigated protein preparations was significantly lower (46% to 62%) than of the initial material (oilcake). PMID:10702992

  15. Recovery and characterization of Balanites aegyptiaca Del. kernel proteins. Effect of defatting, air classification, wet sieving and aqueous ethanol treatment on solubility, digestibility, amino acid composition and sapogenin content.

    Science.gov (United States)

    Mohamed, A M; Wolf, W; Spiess, W E

    2000-02-01

    In order to find alternative protein sources in African regions where protein deficiency in nutrition is prevailing, solubility, in-vitro digestibility, amino acid composition and chemical score of Balanites aegyptiaca Del. kernel proteins were investigated as a function of different processing steps including defatting, air classification, wet sieving and aqueous ethanol treatment. Air classification delivered a fine fraction of 58.1% of the total protein. Applying a wet sieving process, a protein concentrate of 72.9% protein content was achieved but the recovery was very low (35.6%). However, in case of isoelectric precipitation followed by aqueous ethanol treatment both protein content (78.2%) and recovery (53.7%) were high. Data concerning the chemical score revealed, that lysine content of the defatted kernel flour amounted to 74.2% of the recommended FAO/WHO standard level. In-vitro protein digestibility was found to be higher than of legume proteins. The digestible protein of the full fat flour, defatted flour, air classified and wet sieved fine fractions and protein concentrate were 91.9, 93.7, 82.0, 86.4 and 94.2%, respectively. The sapogenin content per 100 g protein of the investigated protein preparations was significantly lower (46% to 62%) than of the initial material (oilcake).

  16. The Influence of Slight Protuberances in a Micro-Tube Reactor on Methane/Moist Air Catalytic Combustion

    OpenAIRE

    Ruirui Wang; Jingyu Ran; Xuesen Du; Juntian Niu; Wenjie Qi

    2016-01-01

    The combustion characteristics of methane/moist air in micro-tube reactors with different numbers and shapes of inner wall protuberances are investigated in this paper. The micro-reactor with one rectangular protuberance (six different sizes) was studied firstly, and it is shown that reactions near the protuberance are mainly controlled by diffusion, which has little effect on the outlet temperature and methane conversion rate. The formation of cavities and recirculation zones in the vicinity...

  17. Influence of Inlet Air Dry-Bulb and Wet-Bulb Temperature on Cooling Effect in Spraying Cooling Tower%喷雾冷却塔进塔干湿球温度对冷却效果的影响

    Institute of Scientific and Technical Information of China (English)

    路建岭; 吴培浩; 余鹏

    2011-01-01

    According to the principle of atoraization cooling, a 80t/h experimental counter-flow no-padding spraying cooling tower was established. And through four experimental conditions the influence of the inlet air dry-bulb /wet-bulb temperature on cooling effect in spraying cooling tower was analyzed. The results showed; when inlet air dry-bulb temperature increased by 2℃, the cooling range reduced by only 0.2℃ and the cooling efficiency only reduced by 3.2% , when inlet air wet-bulb temperature increased by 1. 8℃, the cooling range reduced by 0.8℃ and the cooling efficiency reduced by about 13.4% , which showed that the inlet air wet - bulb temperature had a larger impact on the cooling effect than that of the inlet air dry-bulb temperature in spraying cooling tower.%根据雾化冷却原理,建立了80t/h试验用逆流式无填料喷雾冷却塔,并通过4个工况的试验分析了进塔空气干湿球温度对喷雾冷却塔冷却效果的影响,结果表明:当进塔空气干球温度增加2℃时,冷却温差仅减小0.2℃,冷却效率仅减小0.8%;当进塔空气湿球温度增大1.8℃时,冷却温差减小0.8℃,冷却效率减小13.4%;进塔空气湿球温度对喷雾冷却塔的冷却效果影响较大.

  18. Post-treatment of refinery wastewater effluent using a combination of AOPs (H2O2 photolysis and catalytic wet peroxide oxidation) for possible water reuse. Comparison of low and medium pressure lamp performance.

    Science.gov (United States)

    Rueda-Márquez, J J; Levchuk, I; Salcedo, I; Acevedo-Merino, A; Manzano, M A

    2016-03-15

    The main aim of this work was to study the feasibility of multi-barrier treatment (MBT) consisting of filtration, hydrogen peroxide photolysis (H2O2/UVC) and catalytic wet peroxide oxidation (CWPO) for post-treatment of petroleum refinery effluent. Also the possibility of water reuse or safe discharge was considered. The performance of MBT using medium (MP) and low (LP) pressure lamps was compared as well as operation and maintenance (O&M) cost. Decomposition of organic compounds was followed by means of gas chromatography-mass spectrometry (GC-MS), total organic carbon (TOC) and chemical oxygen demand (COD) analysis. After filtration step (25 μm) turbidity and concentration of suspended solids decreased by 92% and 80%, respectively. During H2O2/UVC process with LP lamp at optimal conditions (H2O2:TOC ratio 8 and UVC dose received by water 5.28 WUVC s cm(-2)) removal of phenolic compounds, TOC and COD was 100%, 52.3% and 84.3%, respectively. Complete elimination of phenolic compounds, 47.6% of TOC and 91% of COD was achieved during H2O2/UVC process with MP lamp at optimal conditions (H2O2:TOC ratio 5, UVC dose received by water 6.57 WUVC s cm(-2)). In order to compare performance of H2O2/UVC treatment with different experimental set up, the UVC dose required for removal of mg L(-1) of COD was suggested as a parameter and successfully applied. The hydrophilicity of H2O2/UVC effluent significantly increased which in turn enhanced the oxidation of organic compounds during CWPO step. After H2O2/UVC treatment with LP and MP lamps residual H2O2 concentration was 160 mg L(-1) and 96.5 mg L(-1), respectively. Remaining H2O2 was fully consumed during subsequent CWPO step (6 and 3.5 min of contact time for LP and MP, respectively). Total TOC and COD removal after MBT was 94.7% and 92.2% (using LP lamp) and 89.6% and 95%, (using MP lamp), respectively. The O&M cost for MBT with LP lamp was estimated to be 0.44 € m(-3) while with MP lamp it was nearly five

  19. DESTRUCTION OF TETRAPHENYLBORATE IN TANK 48H USING WET AIR OXIDATION BATCH BENCH SCALE AUTOCLAVE TESTING WITH ACTUAL RADIOACTIVE TANK 48H WASTE

    Energy Technology Data Exchange (ETDEWEB)

    Adu-Wusu, K; Paul Burket, P

    2009-03-31

    Wet Air Oxidation (WAO) is one of the two technologies being considered for the destruction of Tetraphenylborate (TPB) in Tank 48H. Batch bench-scale autoclave testing with radioactive (actual) Tank 48H waste is among the tests required in the WAO Technology Maturation Plan. The goal of the autoclave testing is to validate that the simulant being used for extensive WAO vendor testing adequately represents the Tank 48H waste. The test objective was to demonstrate comparable test results when running simulated waste and real waste under similar test conditions. Specifically: (1) Confirm the TPB destruction efficiency and rate (same reaction times) obtained from comparable simulant tests, (2) Determine the destruction efficiency of other organics including biphenyl, (3) Identify and quantify the reaction byproducts, and (4) Determine off-gas composition. Batch bench-scale stirred autoclave tests were conducted with simulated and actual Tank 48H wastes at SRNL. Experimental conditions were chosen based on continuous-flow pilot-scale simulant testing performed at Siemens Water Technologies Corporation (SWT) in Rothschild, Wisconsin. The following items were demonstrated as a result of this testing. (1) Tetraphenylborate was destroyed to below detection limits during the 1-hour reaction time at 280 C. Destruction efficiency of TPB was > 99.997%. (2) Other organics (TPB associated compounds), except biphenyl, were destroyed to below their respective detection limits. Biphenyl was partially destroyed in the process, mainly due to its propensity to reside in the vapor phase during the WAO reaction. Biphenyl is expected to be removed in the gas phase during the actual process, which is a continuous-flow system. (3) Reaction byproducts, remnants of MST, and the PUREX sludge, were characterized in this work. Radioactive species, such as Pu, Sr-90 and Cs-137 were quantified in the filtrate and slurry samples. Notably, Cs-137, boron and potassium were shown as soluble as a

  20. Catalytic thermal barrier coatings

    Science.gov (United States)

    Kulkarni, Anand A.; Campbell, Christian X.; Subramanian, Ramesh

    2009-06-02

    A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

  1. Drop splashing is independent of substrate wetting

    CERN Document Server

    Latka, Andrzej; Nagel, Sidney R; de Pablo, Juan J

    2016-01-01

    A liquid drop impacting a dry solid surface with sufficient kinetic energy will splash, breaking apart into numerous secondary droplets. This phenomenon shows many similarities to forced wetting, including the entrainment of air at the contact line. Because of these similarities and the fact that forced wetting has been shown to depend on the wetting properties of the surface, existing theories predict splashing to depend on wetting properties as well. However, using high-speed interference imaging we observe that wetting properties have no effect on splashing for various liquid-surface combinations. Additionally, by fully resolving the Navier-Stokes equations at length and time scales inaccessible to experiments, we find that the shape and motion of the air-liquid interface at the contact line are independent of wettability. We use these findings to evaluate existing theories and to compare splashing with forced wetting.

  2. 正丁烷/氢气/空气混合物催化着火的实验研究%Experimental study on catalytic ignition ofn-C4H10/H2/air mixtures

    Institute of Scientific and Technical Information of China (English)

    钟北京; 于亚薇; 熊鹏飞

    2014-01-01

    通过实验研究了正丁烷/氢气/空气混合物在 Pt 催化剂表面上的催化着火特性。实验发现,氢气在正丁烷/空气混合物的催化着火过程中既存在热作用,也存在化学作用。当化学作用为主导时,可燃混合物的化学催化着火温度明显低于热着火温度。实验结果表明,只有当氢气在可燃混合物的含量大于某个临界值时,化学催化着火才能发生,而且该临界值的大小以及催化着火温度均与可燃混合物的当量比有关。%An experimental study on catalytic ignition ofn-C4H10/H2/air mixtures in the Pt-coated catalyst surface was conducted. Hydrogen had not only thermal, but also chemical effects on the catalytic ignition of the n-C4H10/air mixtures. The chemical catalytic ignition temperature of the combustible mixtures was obviously lower than thermal ignition when chemical effect was dominant. However, chemical catalytic ignition occurred only when hydrogen content in the combustible mixtures was greater than a critical value. The critical value and the catalytic ignition temperature were related to equivalence ratio of the combustible mixtures.

  3. Enhanced Control of Mercury and other HAPs by Innovative Modifications to Wet FGD Processes

    International Nuclear Information System (INIS)

    The overall objective of this project was to learn more about controlling emissions of hazardous air pollutants (HAPs) from coal-fired power plants that are equipped with wet flue gas desulfurization (FGD) systems. The project was included by FETC as a Phase I project in its Mega-PRDA program. Phase I of this project focused on three research areas. These areas in order of priority were: (1) Catalytic oxidation of vapor-phase elemental mercury; (2) Enhanced particulate-phase HAPs removal by electrostatic charging of liquid droplets; and (3) Enhanced mercury removal by addition of additives to FGD process liquor. Mercury can exist in two forms in utility flue gas--as elemental mercury and as oxidized mercury (predominant form believed to be HgCl2). Previous test results have shown that wet scrubbers effectively remove the oxidized mercury from the gas but are ineffective in removing elemental mercury. Recent improvements in mercury speciation techniques confirm this finding. Catalytic oxidation of vapor-phase elemental mercury is of interest in cases where a wet scrubber exists or is planned for SO2 control. If a loW--cost process could be developed to oxidize all of the elemental mercury in the flue gas, then the maximum achievable mercury removal across the existing or planned wet scrubber would increase. Other approaches for improving control of HAPs included a method for improving particulate removal across the FGD process and the use of additives to increase mercury solubility. This paper discusses results related only to catalytic oxidation of elemental mercury

  4. Fe salts as catalyst for the wet oxidation of o-chlorophenol

    Institute of Scientific and Technical Information of China (English)

    XU Xin-hua; HE Ping; JIN Jian; HAO Zhi-wei

    2005-01-01

    Catalytic wet air oxidation (CWAO) of o-chlorophenol in wastewater was studied in a stainless steel autoclave using four different Fe catalysts in the temperature range of 100-200 ℃. Experimental results showed that high rate of o-chlorophenol and CODcr (Chemical Oxygen Demand, mg/L) removal by CWAO was obtained at relatively low temperature and pressure. The catalysts Fe2(SO4)3, FeSO4, Fe2O3 and FeCl3 all exhibited high catalytic activity. More than 93.7% of the initial CODCr and nearly100% of o-chlorophenol were removed at 150 ℃ after 150 min with FeSO4 as catalyst. The CWAO of o-chlorophenol was found to be pseudo-first order reaction with respect to o-chlorophenol, with activation energy of 75.56 k J/mol in the temperature range of100-175 ℃.

  5. 液滴碰撞液膜润湿壁面空气夹带数值分析∗%Numerical analysis on air entrapment during droplet impacting on a wetted surface

    Institute of Scientific and Technical Information of China (English)

    李大树; 仇性启; 郑志伟

    2015-01-01

    A numerical model is developed using the coupled level set and volume of fluid method including heat transfer and contact resistance to simulate air entrapment during a droplet impacting on a wetted surface. The dynamic characteristics of the phase interface are analysed. The mechanisms of deformation of the phase interface and formation of entrapped air are explored. The effects of impacting velocity and thickness of liquid film on characteristics of entrapped air are studied. The mechanism of heat transfer is also obtained in this article. The obtained results are as follows. The pressure difference between liquid and gas before the droplet impacting is the main factor determining the deformation of phases interface and the formation of air entrapment. The larger the impacting velocity, the larger the pressure inside the compressed air film is. When the droplet contacts the liquid film, the velocities of the droplet and liquid film increase to their maximum values, and at the impacting axis, they are approximately the same, nearly half the impacting velocity. The velocity distributions of phase interface of the droplet and liquid film are nearly the same in the area of impacting center. The impacting velocity has important effects on the dimensionless arc from bottom to breaking point and the dimensionless diameter of the air. The dimensionless arc and dimensionless diameter decrease with increasing impacting velocity. The dimensionless deforming heights of the droplet and liquid film are closely related to Stokes number: the larger the Stokes number, the larger the dimensionless deforming heights are, and they can be expressed as a power function with Stokes number. The initial thickness of liquid film also affects dimensionless deforming heights of the droplet and liquid film and dimensionless diameter of the entrapped air: the larger the dimensionless thickness of the liquid film, the larger the dimensionless deforming heights are, and the dimensionless

  6. 夏季空调室外计算湿球温度的选用问题%Selection of outdoor design wet-bulb temperature for summer air conditioning

    Institute of Scientific and Technical Information of China (English)

    刘鸣; 曾婷婷

    2015-01-01

    Presents the climatic zoning in Chinese standard and ASHRAE Standard 90.1-2010. Analyses the difference of outdoor design wet-bulb temperature for summer air conditioning for some cities between Chinese and American standards.Selecting some typical cities in China,adopts the outdoor design parameters for summer stipulated in Chinese and American standards respectively to calculate the cooling load from outdoor design air,and finds that the results in the cities with low and middle wet-bulb temperature are very different.Compared to the outdoor design wet-bulb temperature for summer air conditioning stipulated in American standard,the design parameter for the same city in our standard is generally larger,especially in dry-hot climate area,which increasing the initial cost of air conditioning system designed by our specifications.%介绍了我国标准和 ASHRAE Standard 90.1-2010中的气候分区,分析了中美两国标准中给出的我国一些城市的夏季空调室外计算湿球温度的差异。选择我国部分典型城市,分别采用中美两国标准中给出的夏季室外计算参数计算了新风冷负荷,发现在中、低湿球温度城市二者的计算结果差别很大。相对于美国 ASHRAE 给出的同一城市的夏季空调室外计算湿球温度,我国标准给出的设计参数值普遍偏大,尤其是在干热气候区偏差更大,这必定导致在这类地区设计的空调系统初投资增大。

  7. Air

    Science.gov (United States)

    ... house) Industrial emissions (like smoke and chemicals from factories) Household cleaners (spray cleaners, air fresheners) Car emissions (like carbon monoxide) *All of these things make up “particle pollution.” They mostly come from cars, trucks, buses, and ...

  8. TiO2-sludge carbon enhanced catalytic oxidative reaction in environmental wastewaters applications.

    Science.gov (United States)

    Athalathil, Sunil; Erjavec, Boštjan; Kaplan, Renata; Stüber, Frank; Bengoa, Christophe; Font, Josep; Fortuny, Agusti; Pintar, Albin; Fabregat, Azael

    2015-12-30

    The enhanced oxidative potential of sludge carbon/TiO2 nano composites (SNCs), applied as heterogeneous catalysts in advanced oxidation processes (AOPs), was studied. Fabrification of efficient SNCs using different methods and successful evaluation of their catalytic oxidative activity is reported for the first time. Surface modification processes of hydrothermal deposition, chemical treatment and sol-gel solution resulted in improved catalytic activity and good surface chemistry of the SNCs. The solids obtained after chemical treatment and hydrothermal deposition processes exhibit excellent crystallinity and photocatalytic activity. The highest photocatalytic rate was obtained for the material prepared using hydrothermal deposition technique, compared to other nanocomposites. Further, improved removal of bisphenol A (BPA) from aqueous phase by means of catalytic ozonation and catalytic wet air oxidation processes is achieved over the solid synthesized using chemical treatment method. The present results demonstrate that the addition of TiO2 on the surface of sludge carbon (SC) increases catalytic oxidative activity of SNCs. The latter produced from harmful sludge materials can be therefore used as cost-effective and efficient sludge derived catalysts for the removal of hazardous pollutants. PMID:26223014

  9. Catalytic performance of heteroatom-modified carbon nanotubes in advanced oxidation processes

    Institute of Scientific and Technical Information of China (English)

    João Restivo; Raquel P. Rocha; Adrián M. T. Silva; José J. M. Órfão; Manuel F. R. Pereira; José L. Figueiredo

    2014-01-01

    Multi-walled carbon nanotubes (CNTs) were submitted to chemical and thermal treatments in or-der to incorporate different heteroatoms on the surface. O-, S-and N-containing groups were suc-cessfully introduced onto the CNTs without significant changes of the textural properties. The cata-lytic activity of these heteroatom-modified CNTs was studied in two liquid phase oxidation pro-cesses:catalytic ozonation and catalytic wet air oxidation (CWAO), using oxalic acid and phenol as model compounds. In both cases, the presence of strongly acidic O-containing groups was found to decrease the catalytic activity of the CNTs. On the other hand, the introduction of S species (mainly sulfonic acids) enhanced the removal rate of the model compounds, particularly in the CWAO of phenol. Additional experiments were performed with a radical scavenger and sodium persulfate, in order to clarify the reaction mechanism. Nitrogen functionalities improve the catalytic performance of the original CNTs, regardless of the process or of the pollutant.

  10. Air

    International Nuclear Information System (INIS)

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  11. Cycled storage-discharge plasma catalytic process for toluene removal from indoor air%循环的存储-放电等离子体催化新过程脱除室内空气中甲苯

    Institute of Scientific and Technical Information of China (English)

    范红玉; 李小松; 刘艳霞; 刘景林; 赵德志; 朱爱民

    2011-01-01

    Non-thermal plasmas (NTPs) technique has a great potential for indoor air purification, however, the high energy cost and secondary pollutants formation limit its practical application. To resolve these problems, a cycled storage-discharge (CSD) plasma catalytic process was explored for the removal of low-concentration toluene from indoor air in this study. The performance of toluene storage and plasma catalytic oxidation of adsorbed-state toluene over non-loaded and silver-loaded HZSM-5 catalysts was investigated. The experimental results showed that silver-loaded HZSM-5 catalysts gave a longer breakthrough time than non-loaded HZSM-5 catalysts at the storage stage (storage condition: 0. 1 g · m-3 C7H8, 40% relative humidity (RH, 25℃), 2000 ml · min-1 flow rate of simulated air). With input power of 40 W, the adsorbed-state toluene could be almost oxidized to CO2 in 10 min at the discharge stage (carbon balance about 100%, CO2 selectivity 98. 2%). It was further proved that there was no toluene desorbed during the process of plasma catalytic oxidation by on-line detection with mass spectrometry (MS) and Fourier transform infrared spectrometry (FTIR). Preliminary investigation on the stability of the CSD process for toluene removal was conducted. This study provides a novel plasma catalytic process for removing toluene from indoor air.%@@ 引言 室内空气中的挥发性有机化合物(VOCs),如甲醛(HCHO)、苯(CH)、甲苯(CH)等,是一类对人体有极大危害的室内空气污染物[1-2].传统的脱除VOCs的方法有吸附法、催化氧化法、热焚烧法等,这些方法在经济上或处理效率上或多或少存在缺陷.用于室内空气中VOCs脱除的理想方法应该同时具备脱除效率高、室温脱除、操作简单、能耗低及无二次污染物等特点.

  12. Experimental and Numerical Study on Characteristics of MethaneWet Air Reforming in a Micro-combustor%微细腔内甲烷-湿空气重整特性试验与数值模拟

    Institute of Scientific and Technical Information of China (English)

    赵柳洁; 冉景煜; 张力; 王方明

    2012-01-01

    To study the auto-thermal reforming process of methane-wet air in a micro-combustor,a straight tube experimental system has been established with a tube diameter of 2 mm,based on which experimental tests and 3D numerical simulation are performed to analyze the conversion characteristics of the reforming,focusing on the influence of reaction temperature and feed gas ratio on the methane conversion rate and H2 yield.Study results show that at the same mass flow of methane,both the methane conversion rate and H2 yield increase with rising temperature,air-methane ratio and steam-methane ratio;the influence of air-methane ratio on methane conversion rate is greater than on H2 yield.The system with low mass flow of feed gas is more efficient than that with high mass flow in H2 yield during methane-wet air reforming.Test results agree well with that of the numerical simulation.%针对甲烷-湿空气在微细腔内的自热重整,建立了直径为2mm的微细直管试验系统,采用试验研究和三维数值计算两种方法分析了微反应器内甲烷-湿空气自热重整转化特性,并重点分析了反应温度、原料气组分比例变化对重整反应中甲烷转化率和氢气产率的影响.结果表明:在相同的甲烷流量工况下,随着温度的升高以及空/碳比和水/碳比的增大,甲烷转化率和氢气产率均增大,其中空-碳比对甲烷转化率的影响比对氢气产率的影响大;进气质量流量较小的体系比较大的体系在重整产氢方面的效果好.试验和数值模拟得到的结果比较一致.

  13. Modeled Wet Nitrate Deposition

    Data.gov (United States)

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  14. Surface and Hydrodynamic Forces in Wetting Films

    OpenAIRE

    Pan, Lei

    2013-01-01

    The process of froth flotation relies on using air bubbles to collect desired mineral particles dispersed in aqueous media on the surface, while leaving undesirous mineral particles behind. For a particle to be collected on the surface of a bubble, the thin liquid films (or wetting films) of water formed in between must rupture. According to the Frumkin-Derjaguin isotherm, it is necessary that wetting films can rupture when the disjoining pressures are negative. However, the negative disjoini...

  15. Automobile air pollution: control equipment--catalytic converters. Volume 2. 1977-January, 1980 (citations from the Engineering Index Data Base). Report for 1977-Jan 80

    Energy Technology Data Exchange (ETDEWEB)

    Cavagnaro, D.M.

    1980-02-01

    The citations of worldwide engineering literature cover automotive catalytic converters. Included are such topics as converter design and materials, performance tests, effectiveness in pollutant reduction, catalyst poisoning, catalyst selection, chemistry involved in the emission control, and the overall feasibility of using these converters under normal driving conditions. Control of sulfuric acid and sulfate emissions is also discussed. (This updated bibliography contains 142 abstracts, 37 of which are new entries to the previous edition.)

  16. Haptic perception of wetness

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kosters, N.D.; Daanen, H.A.M.; Kappers, A.M.L.

    2011-01-01

    The sensation of wetness is well-known but barely investigated. There are no specific wetness receptors in the skin, but the sensation is mediated by temperature and pressure perception. In our study, we have measured discrimination thresholds for the haptic perception of wetness of three di erent t

  17. Reaction mechanism and degradation course of azo dyes by catalytic wet peroxide oxidation(CWPO)%催化湿式过氧化(CWPO)偶氮染料反应机理及降解历程研究

    Institute of Scientific and Technical Information of China (English)

    张蕾; 马宏瑞

    2011-01-01

    采用浸渍法制备出具有较高催化活性的催化剂CuO/γ-Al2O3,通过XRD、电镜等手段对催化剂进行了表征。降解了几种不同结构的偶氮染料,并通过改变CWPO的反应条件推断了其催化反应机理。采用紫外/可见分光光度计(UV-Vis)和傅里叶红外光谱仪(IR)等手段对染料降解过程进行跟踪和分析,对比染料处理前后紫外可见光谱与红外光谱图的变化,说明染料分子结构中的偶氮键发生断裂,破坏了分子结构的偶氮-苯环共轭发色体系,从而达到了脱色的目的。并借助水杨酸验证了CWPO体系中.OH的产生及CWPO反应机理。%The catalyst CuO/γ-Al2O3 with high catalytic activity by impregnation was prepared,and were examined by XRD、SEM to characterize the catalyst.Azo dyes of several different structures were degraded,and the reaction conditions were changed to study the reaction mechanism of CWPO.The UV/Visible spectrophotometer(UV-Vis) and the Fourier transform infrared spectrometer(IR) were used to track and analyze the degradation process of the dyes.Compared the UV-Vis and IR spectra before and after wastewater treatment,indicating the structure of the azo dye molecules bond was broken,destroyed azo benzene conjugated chromophoric system of the molecular structure,so as to achieve the purpose of bleaching.The salicylic acid was used to infer the ·OH generation and reaction mechanism in the CWPO system.

  18. The Relationship Between Soil Air Filled Porosity and Soil Methane Oxidation is Almost Identical in Both Dry and Wet Temperate Eucalypt Forests

    Science.gov (United States)

    Fest, B. J.; Wardlaw, T.; Hinko-Najera, N.; Arndt, S. K.

    2015-12-01

    In order to gain a better understanding of the temporal variation in soil methane (CH4) exchange in temperate evergreen eucalypt forests in south-eastern Australia we measured soil CH4 exchange in high temporal resolution (every 2 hours or less) over two consecutive years (Wombat State Forest, Victoria, AUS) and over one year (Warra, Tasmania, AUS) in two temperate Eucalyptus obliqua (L. Her) forests with contrasting annual precipitation (Wombat State Forest = 870 mm yr-1, Warra = 1700 mm yr-1). Both forests were continuous CH4 sinks with the Victorian site having a sink strength of -1.79 kg CH4 ha-1 yr-1 and the Tasmanian site having a sink strength of -3.83 kg CH4 ha-1 yr-1. Our results show that CH4 uptake was strongly controlled by soil moisture at both sites and explained up to 90% of the temporal variability in CH4 uptake. Furthermore, when soil moisture was expressed as soil air filled porosity (AFP) we were able to predict the CH4 uptake of one site by the linear regression between AFP and CH4 uptake from the other site. Soil temperature only had an apparent control over seasonal variation in CH4 uptake during periods when soil moisture and soil temperature were closely correlated. The fluctuation of the generally low soil nitrogen levels did not influence soil CH4 uptake at either site.

  19. EFFECTS OF FEED CONCENTRATION AND WATER VAPOR ON CATALYTIC COMBUSTION OF ETHYL ACETATE AND BENZENE IN AIR OVER CR-ZSM-5 CATALYST

    Directory of Open Access Journals (Sweden)

    Ahmad Zuhairi Abdullah

    2010-09-01

    Full Text Available Catalytic combustion of ethyl acetate (EAc and benzene (Bz over chromium exchanged ZSM-5 (Si/Al=240 is reported. An 11 mm i.d. fixed-bed catalytic reactor, operated at temperatures between 100 oC and 500 oC, and under excess oxygen condition, was used for the catalytic activity measurement. Apparent order of reaction and apparent activation energy were determined by operating the reactor differentially at a gas hourly space velocity (GHSV of 78,900 h-1 and feed concentrations between 3,500 ppm to 17,700 ppm and 3,700 to 12,400 ppm for ethyl acetate and benzene, respectively. Ethyl acetate was more reactive than benzene due to highly reactive carbonyl group in the molecule. The combustion process satisfactorily fitted pseudo first-order kinetics with respect to organic concentration and a zero-order dependence on the oxygen concentration. The presence of water vapor (9,000 ppm in the feed stream was found to weaken the reactivity of these organics which could also be demonstrated with increases in the activation energy from 23.1 kJ/mole to 37.6 kJ/mole for ethyl acetate and from 27.6 kJ/mole to 46.1 kJ/mole for benzene. Water vapor was found to play a positive role in the formation of carbon dioxide yield in ethyl acetate combustion. Deactivation of catalyst by water appeared to be only temporary and the activity reverted back to its original value once the source of water vapor was removed.

  20. PREFACE: Dynamics of wetting Dynamics of wetting

    Science.gov (United States)

    Grest, Gary S.; Oshanin, Gleb; Webb, Edmund B., III

    2009-11-01

    Capillary phenomena associated with fluids wetting other condensed matter phases have drawn great scientific interest for hundreds of years; consider the recent bicentennial celebration of Thomas Young's paper on equilibrium contact angles, describing the geometric shape assumed near a three phase contact line in terms of the relevant surface energies of the constituent phases [1]. Indeed, nearly a century has passed since the seminal papers of Lucas and Washburn, describing dynamics of capillary imbibition [2, 3]. While it is generally appreciated that dynamics of fluid wetting processes are determined by the degree to which a system is out of capillary equilibrium, myriad complications exist that challenge the fundamental understanding of dynamic capillary phenomena. The topic has gathered much interest from recent Nobel laureate Pierre-Gilles de Gennes, who provided a seminal review of relevant dissipation mechanisms for fluid droplets spreading on solid surfaces [4] Although much about the dynamics of wetting has been revealed, much remains to be learned and intrinsic technological and fundamental interest in the topic drives continuing high levels of research activity. This is enabled partly by improved experimental capabilities for resolving wetting processes at increasingly finer temporal, spatial, and chemical resolution. Additionally, dynamic wetting research advances via higher fidelity computational modeling capabilities, which drive more highly refined theory development. The significance of this topic both fundamentally and technologically has resulted in a number of reviews of research activity in wetting dynamics. One recent example addresses the evaluation of existing wetting dynamics theories from an experimentalist's perspective [5]. A Current Opinion issue was recently dedicated to high temperature capillarity, including dynamics of high temperature spreading [6]. New educational tools have recently emerged for providing instruction in wetting

  1. Wetting in electrolyte solutions.

    Science.gov (United States)

    Ibagon, Ingrid; Bier, Markus; Dietrich, S

    2013-06-01

    Wetting of a charged substrate by an electrolyte solution is investigated by means of classical density functional theory applied to a lattice model. Within the present model the pure, i.e., salt-free solvent, for which all interactions are of the nearest-neighbor type only, exhibits a second-order wetting transition for all strengths of the substrate-particle and the particle-particle interactions for which the wetting transition temperature is nonzero. The influences of the substrate charge density and of the ionic strength on the wetting transition temperature and on the order of the wetting transition are studied. If the substrate is neutral, the addition of salt to the solvent changes neither the order nor the transition temperature of the wetting transition of the system. If the surface charge is nonzero, upon adding salt this continuous wetting transition changes to first-order within the wide range of substrate surface charge densities and ionic strengths studied here. As the substrate surface charge density is increased, at fixed ionic strength, the wetting transition temperature decreases and the prewetting line associated with the first-order wetting transition becomes longer. This decrease of the wetting transition temperature upon increasing the surface charge density becomes more pronounced by decreasing the ionic strength. PMID:23758391

  2. Wet oxidation of quinoline

    DEFF Research Database (Denmark)

    Thomsen, A.B.; Kilen, H.H.

    1998-01-01

    time was less important within the range studied. Nitrifying bacteria were used to measure the inhibition from wet oxidative-treated samples to study the effect of the (wet oxidation) reaction conditions. Wet oxidation made quinoline more toxic to Nitrosomonas. This was observed for Nitrobacter as well......The influence of oxygen pressure (0.4 and 2 MPa). reaction time (30 and 60 min) and temperature (260 and 280 degrees C) on the wet oxidation of quinoline has been studied. The dominant parameters for the decomposition of quinoline were oxygen pressure and reaction temperature. whereas the reaction....... The combined wet oxidation and biological treatment of reaction products resulted in 91% oxidation of the parent compound to CO2 and water. Following combined wet oxidation and biological treatment the sample showed low toxicity towards Nitrosomonas and no toxicity towards Nitrobacter. (C) 1998 Elsevier...

  3. Catalytic effect of heat-treated iron and copper phthalocyanines in non-aqueous electrolyte Li/air batteries. A review

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Sheng S.; Ren, Xiaoming; Tran, Dat T.; Read, Jeffrey [U.S. Army Research Laboratory, RDRL-SED-C, Adelphi, MD (United States)

    2012-07-01

    In this review, we summarize our research on the characterization of FeCu/C catalyst and its effect in non-aqueous electrolyte Li/air cells. The catalyst is synthesized by impregnating metal phthalocyanine complex into a high surface area carbon, followed by pyrolyzing the complex-loaded carbon under argon atmosphere. High resolution X-ray photoelectron spectroscopy (HR-XPS) results indicate that the metals in the catalyst are present in the form of a mixture of metal-nitrogen complexes (MN) and metal oxides (MO). Using coin-type Li/air cells as the testing vehicle, the FeCu/C is determined to affect the Li/air cells in three manners: (1) It catalyzes two-electron oxygen reduction reaction (ORR) to form Li{sub 2}O{sub 2}, which reduces discharge polarization of the Li/air cells, (2) It promotes chemical disproportionation of Li{sub 2}O{sub 2}, which leads to an apparent four-electron ORR, and (3) It induces reduction of electrolyte solvents, which adds a second lower discharge voltage plateau at {proportional_to} 1.7 V. In addition, the FeCu/C catalyst increases the open circle voltage (OCV) recovery rate of the Li/air cells as a result of the chemical disproportionation of Li{sub 2}O{sub 2}, which releases oxygen and the resulting oxygen participates in OCV recovery. (orig.)

  4. MULTI-POLLUTANT CONTROL USING MEMBRANE--BASED UP-FLOW WET ELECTROSTATIC PRECIPITATION

    Energy Technology Data Exchange (ETDEWEB)

    James Reynolds

    2004-10-29

    This is the Final Report of the ''Multi-Pollutant Control Using Membrane-Based Up-flow Wet Electrostatic Precipitation'' project funded by the US Department of Energy's National Energy Technology Laboratory under DOE Award No. DE-FC26-02NT41592 to Croll-Reynolds Clean Air Technologies (CRCAT). In this 18 month project, CRCAT and its team members conducted detailed emission tests of metallic and new membrane collection material within a wet electrostatic precipitator (WESP) at First Energy's Penn Power's Bruce Mansfield (BMP) plant in Shippingport, Pa. The Membrane WESP was designed to be as similar as the metallic WESP in terms of collection area, air-flow, and electrical characteristics. Both units are two-field units. The membrane unit was installed during the 2nd and 3rd quarters of 2003. Testing of the metallic unit was performed to create a baseline since the Mansfield plant had installed selective catalytic reduction equipment for NOx control and a sodium bisulfate injection system for SO3 control during the spring of 2003. Tests results on the metallic WESP were consistent with previous testing for PM2.5, SO3 mist and mercury. Testing on the membrane WESP demonstrated no adverse impact and equivalent removal efficiencies as that of the metallic WESP. Testing on both units was performed at 8,000 acfm and 15,000 acfm. Summary results are shown.

  5. Electro Catalytic Oxidation (ECO) Operation

    Energy Technology Data Exchange (ETDEWEB)

    Morgan Jones

    2011-03-31

    The power industry in the United States is faced with meeting many new regulations to reduce a number of air pollutants including sulfur dioxide, nitrogen oxides, fine particulate matter, and mercury. With over 1,000 power plants in the US, this is a daunting task. In some cases, traditional pollution control technologies such as wet scrubbers and SCRs are not feasible. Powerspan's Electro-Catalytic Oxidation, or ECO{reg_sign} process combines four pollution control devices into a single integrated system that can be installed after a power plant's particulate control device. Besides achieving major reductions in emissions of sulfur dioxide (SO{sub 2}), nitrogen oxides (NOx), fine particulate matter (PM2.5) and mercury (Hg), ECO produces a highly marketable fertilizer, which can help offset the operating costs of the process system. Powerspan has been operating a 50-MW ECO commercial demonstration unit (CDU) at FirstEnergy Corp.'s R.E. Burger Plant near Shadyside, Ohio, since February 2004. In addition to the CDU, a test loop has been constructed beside the CDU to demonstrate higher NOx removal rates and test various scrubber packing types and wet ESP configurations. Furthermore, Powerspan has developed the ECO{reg_sign}{sub 2} technology, a regenerative process that uses a proprietary solvent to capture CO{sub 2} from flue gas. The CO{sub 2} capture takes place after the capture of NOx, SO{sub 2}, mercury, and fine particulate matter. Once the CO{sub 2} is captured, the proprietary solution is regenerated to release CO{sub 2} in a form that is ready for geological storage or beneficial use. Pilot scale testing of ECO{sub 2} began in early 2009 at FirstEnergy's Burger Plant. The ECO{sub 2} pilot unit is designed to process a 1-MW flue gas stream and produce 20 tons of CO{sub 2} per day, achieving a 90% CO{sub 2} capture rate. The ECO{sub 2} pilot program provided the opportunity to confirm process design and cost estimates, and prepare for large

  6. Study on flaking of wet corn by heating

    Institute of Scientific and Technical Information of China (English)

    WANG Mingming; WANG Defu

    2007-01-01

    Flaking on high-moisture corn (wet corn) by hot-air heating was studied in the paper. The wet-heating approach was beneficial to improve corn gelatinization by experimental results. By the experiments, a set of optimal parameters was obtained: hot-air temperature 120-130 ℃, heating duration 70 min, gap between rollers 0.5-1.0 mm, 150-200 r·min-1 for rotational speed of rollers.

  7. Wetting Transition in Water

    Science.gov (United States)

    Friedman, S. R.; Khalil, M.; Taborek, P.

    2013-11-01

    Optical images were used to study the wetting behavior of water on graphite, sapphire, and quartz along the liquid vapor coexistence curve from room temperature to 300°C. Wetting transitions were identified by the temperature at which the contact angle decreased to zero and also by the disappearance of dropwise condensation. These two methods yielded consistent values for the wetting temperatures, which were 185°C, 234°C, and 271°C for water on quartz, sapphire, and graphite, respectively. We compare our results with the theoretical predictions based on a simplified model of the water-substrate potential and sharp interfaces.

  8. Traction of Pneumatic Tires on Wet Runways

    Science.gov (United States)

    Horne, Walter B.; Joyner, Upshur T.

    1965-01-01

    Recent work on the traction of pneumatic tires on wet runways is discussed, and it is shown that a loss of tire traction adversely affects cross-wind landings. The effect of runway surface texture is discussed,, and a simple method for measuring surface texture is described. A preliminary correlation of tire traction with surface texture is shown. Results of work at Langley Research Center on the use of air jets to improve tire traction on wet or flooded runways indicate that this is a promising approach for alleviating the large losses in tire braking and sideways traction that occur when tire hydroplaning occurs on a flooded runway.

  9. Adsorption and wetting.

    NARCIS (Netherlands)

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption

  10. Adsorption and wetting.

    OpenAIRE

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption and wetting are derived. The surface pressure of a film, formed by vapour adsorption on a solid surface, is calculated by integrating the vapour adsorption isotherm. The surface pressure at the sat...

  11. Study on the Degradation of Bamboo Alkaline Lignin by Catalytic Wet Air Oxidation to Obtain Aromatic Aldehydes%竹子碱木素催化湿空气氧化降解生成芳香醛的研究

    Institute of Scientific and Technical Information of China (English)

    周生飞; 詹怀宇; 付时雨

    2010-01-01

    对竹子碱木素进行了催化湿空气氧化降解.结果表明,竹子碱木素催化湿空气氧化的丰要降解产物为 3 种芳香醛,含量从高到低依次为香草醛、对羟基苯甲醛和丁香醛.芳香醛浓度随降解时间的增加先升高后降低;催化剂的使用对芳香醛浓度有显著的影响,但不改变 3 种芳香醛的含量相对大小顺序;催化剂能较大地提高芳香醛的最岛浓度,且能明显缩短芳香醛浓度达到极大值的时间;与无催化剂或蒽醌(AQ)作为催化剂相比,CuSO4/FeCl3 作为催化剂时,能使芳香醛的浓度提高 1 倍以上,香草醛、对羟基苯甲醛、丁香醛的最高浓度分别为 1.34、1.07、0.59 g/L,总芳香醛的最高浓度为 2.87 g/L.

  12. Mathematical model and general laws of wet compression

    Institute of Scientific and Technical Information of China (English)

    王永青; 刘铭; 廉乐明; 何健勇; 严家騄

    2002-01-01

    Wet compression is an effective way to enhance the performance of gas turbines and it has attracted a good deal of attention in recent years. The one-sidedness and inaccuracy of previous studies,which took concentration gradient as mass transfer potential are discussed. The mass transfer process is analyzed from the viewpoint of non-equilibrium thermodynamics,by taking generalized thermodynamic driving force as mass transfer potential,and the corresponding mass-transfer coefficient is obtained using the heat and mass transfer equilibrium occurring between moist air and water droplets at wet-bulb temperature for the sake of avoiding complex tests and providing more accurate formulas. A mathematical model of wet compression is therefore established,and the general laws of wet compression are investigated. The results show that the performance of atomizer is critical for wet compression and wet compression is more suitable for compressors with higher pressure ratio and longer compression time.

  13. Using wet FGD systems to absorb mercury

    Energy Technology Data Exchange (ETDEWEB)

    Renninger, S.A.; Farthing, G.A.; Ghorishi, S.B. (and others) [Babcock and Wilcox Co. (US)

    2004-10-01

    For the past 12 years, the Babcock and Wilcox Company has been striving to develop mercury-reduction techniques that utilize, whenever possible, existing plant pollution control devices. This article discusses one such technique, which has demonstrated the potential for removing more than 95% of oxidized mercury in a wet flue gas desulfurization system at a low incremental cost and with little or no impact on the system's operation or SO{sub 2} removal performance. B & W's techniques enhance the mercury control ability of wet FGD systems using sodium hydrosulfide injection. This has been tested in a combined air quality control system at Mt. Storm Power Station in West Virginia comprising an SCR system and ESP with a wet FGD system. 6 figs.

  14. Catalytic Partial Oxidation of Methane with Air to Syngas in a Pilot-Plant-Scale Spouted Bed Reactor%甲烷空气部分氧化制合成气喷动床反应器的研究

    Institute of Scientific and Technical Information of China (English)

    魏伟胜; 徐建; 方大伟; 鲍晓军

    2003-01-01

    On the basis of hydrodynamic and scaling-up studies, a pilot-plant-scale thermal spouted bed reactor (50 mm in ID and 1500 mm in height) was designed and fabricated by scaling-down cold simulators. It was tested for making syngas via catalytic partial oxidation (CPO) of methane by air. The effects of various operating conditions such as operating pressure and temperature, feed composition, and gas fiowrate etc. on the CPO process were investigated. CH4 conversion of 92.2% and selectivity of 92.3% and 83.3% to CO and H2, respectively, were achieved at the pressure of 2.1 MPa. It was found that when the spouted bed reactor was operated within the stable spouting flow regime, the temperature profiles along the bed axis were much more uniform than those operated within the fixed-bed regime. The CH4 conversion and syngas selectivity were found to be close to thermodynamic equilibrium limits. The results of the present investigation showed that spouted bed could be considered as a potential type of chemical reactor for the CPO process of methane.

  15. Wrinkling of wet paper

    Science.gov (United States)

    Kim, Ho-Young; Kim, Jungchul; Mahadevan, L.

    2011-11-01

    It is a mundane experience that paper stained with water wrinkles. It is because a wetted portion of paper, which swells due to the hygroexpansive nature of the cellulose fiber network, deforms out of its original plane. Here we quantify the dynamics of wrinkling of wet paper coupled to the capillary imbibition of water into paper using a combination of experiment and theory. While supplying water from a capillary tube that touches the center of a paper strip, we measure the spreading rate of the wet area, wait time for the out-of-plane buckling, and temporal growth of a wrinkling magnitude. Using a theoretical model assuming a linear increase of the strain and an exponential decay of the elastic modulus with the water concentration, we construct scaling laws to predict the simultaneous capillary imbibition and wrinkling rates. This work was supported by the Wyss Institute of Harvard University.

  16. 水蒸气和空气活化对VPO催化剂物性及催化性能的影响%INFLUENCE OF STEAM AND AIR ACTIVATION ON THE PHYSICAL PTOPERTY AND CATALYTIC PERFORMANCE OF VPO CATALYSTS

    Institute of Scientific and Technical Information of China (English)

    许磊; 薛东; 王海波; 佟明友

    2012-01-01

    Vanadium phosphate oxide (VPO) catalyst precursor was activated under the atmosphere of air and steam/air (S/A) mixed gas respectively. The activated catalyst samples were characterized by XRD, XPS and SEM to study their crystal structure and surface property. Results showed that after activation under S/A mixed gas and air, the main crystal phase of the catalyst was (VO)2P2O7 and VO-PO4, respectively. The presence of water vapor during activation reduced the average valence state of vanadium (AV),but increased the P/V atomic ratio of catalyst surface. The catalytic performance of these prepared catalysts was evaluated by selective oxidation of w-butane to maleic anhydride reaction. It was shown that catalyst FVO-1 activated by mixed gas with S/A volume ratio of 1/3, having an AV of 4. 198 and P/V atomic ratio of 1. 17 exhibited good catalytic performance: its conversion of butane was 87. 10% and the selectivity of maleic anhydride reached 72. 89%.%在对钒磷氧(VPO)催化剂的前躯体进行活化的过程中,分别采用空气和水蒸气/空气混合气作为活化氛围.通过X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)等表征手段,考察了不同气氛活化催化剂的晶相结构和表面性质.结果表明:采用水蒸气/空气活化的VPO催化剂的主要晶相是(VO)2P2O7,而采用空气活化的催化剂的主要晶相是VOPO4;水蒸气的加入降低了催化剂中钒的平均价态(AV值),提高了表面P/V原子比.当采用水蒸气/空气体积比1:3的混合气活化时,所得催化剂FVO-1的P/V原子比为1.17,AV值为4.198.FVO-1催化剂对正丁烷选择性氧化制顺丁烯二酸酐反应的催化性能评价结果表明,正丁烷转化率达到87.10%,顺丁烯二酸酐选择性达到72.89%.

  17. Methods and apparatus for catalytic hydrothermal gasification of biomass

    Science.gov (United States)

    Elliott, Douglas C.; Butner, Robert Scott; Neuenschwander, Gary G.; Zacher, Alan H.; Hart, Todd R.

    2012-08-14

    Continuous processing of wet biomass feedstock by catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent separation of sulfur contaminants, or combinations thereof. Treatment further includes separating the precipitates out of the wet feedstock, removing sulfur contaminants, or both using a solids separation unit and a sulfur separation unit, respectively. Having removed much of the inorganic wastes and the sulfur that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

  18. Wetting of real surfaces

    CERN Document Server

    Bormashenko, Edward Yu

    2013-01-01

    The problem of wetting and drop dynamics on various surfaces is very interesting from both the scientificas well as thepractical viewpoint, and subject of intense research.The results are scattered across papers in journals, sothis workwill meet the need for a unifying, comprehensive work.

  19. 常温常压下等离子体催化脱除空气中的苯%Plasma-catalytic removal of benzene from atmospheric pressure air at normal temperature

    Institute of Scientific and Technical Information of China (English)

    丁慧贤; 张增凤; 徐占春

    2012-01-01

    苯是典型的室内空气污染物,严重影响人体健康。在大气压及35℃下,通过在催化剂上进行介质阻挡放电的方式,进行了等离子体一催化氧化脱除空气中苯的研究。当气体中C6H6的体积分数为103.5X10~、H:0的体积分数为1.0%、空气为平衡气,输入能量密度为114J/L,空速为16500h^-1时,苯的脱除率可达93.5%。而在同样实验条件下,单纯等离子体脱除苯和单纯催化氧化脱除苯的脱除率分别为62.8%和9.0%。这一实验结果说明,等离子体与Ag/CeO,催化剂在催化氧化空气中苯的过程中产生了协同效应,等离子体产生的活性自由基在Ag/CeO,催化剂催化氧化苯的氧化一还原循环过程中起到了至关重要的作用。%Aimed at addressing benzene (C6H6 ) , a typical indoor air pollutant threatening to cause serious health disorders in human beings, this paper reports plasma-catalytic oxidation of benzene in gas streams via dielectric barrier discharges over Ag/Ce02 pellets at atmospheric pressure and 35 ℃. A feed gas mixture of 103.5 x 10-6 C6H6, 1.0% H20 in air, GHSV of 16 500 h^-l, and input discharge energy density of 114 J/L contribute to the benzene removal rate of 93.5%. But the same experimental conditions

  20. Physicochemical properties and combustion behavior of duckweed during wet torrefaction.

    Science.gov (United States)

    Zhang, Shuping; Chen, Tao; Li, Wan; Dong, Qing; Xiong, Yuanquan

    2016-10-01

    Wet torrefaction of duckweed was carried out in the temperature range of 130-250°C to evaluate the effects on physicochemical properties and combustion behavior. The physicochemical properties of duckweed samples were investigated by ultimate analysis, proximate analysis, FTIR, XRD and SEM techniques. It was found that wet torrefaction improved the fuel characteristics of duckweed samples resulting from the increase in fixed carbon content, HHVs and the decrease in nitrogen and sulfur content and atomic ratios of O/C and H/C. It can be seen from the results of FTIR, XRD and SEM analyses that the dehydration, decarboxylation, solid-solid conversion, and condensation polymerization reactions were underwent during wet torrefaction. In addition, the results of thermogravimetric analysis (TGA) in air indicated that wet torrefaction resulted in significant changes on combustion behavior and combustion kinetics parameters. Duckweed samples after wet torrefaction behaved more char-like and gave better combustion characteristics than raw sample.

  1. WET SOLIDS FLOW ENHANCEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-03-25

    The yield locus, tensile strength and fracture mechanisms of wet granular materials were studied. The yield locus of a wet material was shifted to the left of that of the dry specimen by a constant value equal to the compressive isostatic stress due to pendular bridges. for materials with straight yield loci, the shift was computed from the uniaxial tensile strength, either measured in a tensile strength tester or calculated from the correlation, and the angle of internal friction of the material. The predicted shift in the yield loci due to different moisture contents compare well with the measured shift in the yield loci of glass beads, crushed limestone, super D catalyst and Leslie coal. Measurement of the void fraction during the shear testing was critical to obtain the correct tensile strength theoretically or experimentally.

  2. Wetting phenomena in electrolyte solutions

    OpenAIRE

    Ibagon, Ingrid

    2014-01-01

    The present study analyzes wetting phenomena in electrolyte solutions. They are investigated by means of classical density functional theory. First, the wetting of a charged substrate by an electrolyte solution is studied with emphasis on the influence of the substrate charge density and of the ionic strength on the wetting transition temperature and on the order of the wetting transition. The corresponding models consist of solvent particles, anions, and cations. Two mean field approaches ar...

  3. Wetting of porous solids.

    Science.gov (United States)

    Patkar, Saket; Chaudhuri, Parag

    2013-09-01

    This paper presents a simple, three stage method to simulate the mechanics of wetting of porous solid objects, like sponges and cloth, when they interact with a fluid. In the first stage, we model the absorption of fluid by the object when it comes in contact with the fluid. In the second stage, we model the transport of absorbed fluid inside the object, due to diffusion, as a flow in a deforming, unstructured mesh. The fluid diffuses within the object depending on saturation of its various parts and other body forces. Finally, in the third stage, oversaturated parts of the object shed extra fluid by dripping. The simulation model is motivated by the physics of imbibition of fluids into porous solids in the presence of gravity. It is phenomenologically capable of simulating wicking and imbibition, dripping, surface flows over wet media, material weakening, and volume expansion due to wetting. The model is inherently mass conserving and works for both thin 2D objects like cloth and for 3D volumetric objects like sponges. It is also designed to be computationally efficient and can be easily added to existing cloth, soft body, and fluid simulation pipelines. PMID:23846102

  4. On the effect of soil wetness on thermal stress

    Science.gov (United States)

    Ookouchi, Y.; Segal, M.; Pielke, R. A.; Mahrer, Y.

    1987-03-01

    A coupled atmosphere-soil model was applied in order to evaluate the impact of soil wetness on human stress in the absence of horizontal gradients in moisture. The results are illustrated and discussed with consideration to various combinations of wind speed and lower level atmospheric moisture during daylight hours with summer weather conditions. A thermal index composed of the air temperature and wet-bulb temperature does not show major changes as a function of variation of soil mosture. When wind speed and solar radiation are also considered, in a more detailed thermal index, relatively wet soil is associated with the optimal thermal comfort.

  5. Wet oxidation of salicylic acid solutions.

    Science.gov (United States)

    Collado, Sergio; Garrido, Laura; Laca, Adriana; Diaz, Mario

    2010-11-15

    Salicylic acid is a frequent pollutant in several industrial wastewaters. Uncatalyzed wet air oxidation, which is a promising technique for the treatment of phenolic effluents, has not been analyzed yet for the removal of salicylic acid. The effect of different conditions of pH (1.3-12.3), pressure (1.0-4.1 MPa), temperature (413-443 K), and initial concentrations (1.45-14.50 mM) on the wet oxidation of salicylate/salicylic acid solutions have here been investigated. The pH value of the reaction media was found to be a key parameter for the rate of the oxidation process with an optimum at pH 3.1, when the concentrations of salicylic acid and salicylate were similar. The oxidation reaction followed pseudofirst-order kinetics with respect to salicylic acid and 0.82 order with respect to dissolved oxygen. Additionally, the evolution of the color during the wet oxidation was analyzed and discussed in relation with the formation of intermediate compounds. Then, a reaction pathway for the noncatalytic wet oxidation of the salicylic acid was proposed.

  6. Catalytic distillation structure

    Science.gov (United States)

    Smith, Jr., Lawrence A.

    1984-01-01

    Catalytic distillation structure for use in reaction distillation columns, a providing reaction sites and distillation structure and consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and being present with the catalyst component in an amount such that the catalytic distillation structure consist of at least 10 volume % open space.

  7. Catalytic combustor for hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Mercea, J.; Grecu, E.; Fodor, T.; Kreibik, S.

    1982-01-01

    The performance of catalytic combustors for hydrogen using platinum-supported catalysts is described. Catalytic plates of different sizes were constructed using fibrous and ceramic supports. The temperature distribution as well as the reaction efficiency as a function of the fuel input rate was determined, and a comparison between the performances of different plates is discussed.

  8. Research progress of catalysts for producing N-phosphonomethyl glycine by air (oxygen) catalytic oxidation%空气(氧气)催化氧化合成草甘膦催化剂的研究进展

    Institute of Scientific and Technical Information of China (English)

    陈丹; 李国儒; 黄敏建; 陈标华; 银凤翔

    2014-01-01

    用于空气(氧气)催化氧化双甘膦合成草甘膦的催化剂主要有活性炭催化剂、贵金属催化剂和过渡金属催化剂。本文分别概述了这3种催化剂的研究进展,分析比较了这些催化剂的优点和缺点:活性炭催化剂成本低廉、制备简单但是套用次数少,副产甲醛含量高;贵金属催化剂不仅收率高、产品质量好,而且催化剂可多次套用,但是成本过高,制备和再生也困难;过渡金属催化剂属均相催化,催化剂和产物易分离,但是产品收率较低。最后结合国内现状,认为开发一种催化效果更优、生产成本更低廉、使用和再生简单且环境友好的催化剂是国内草甘膦生产企业亟待解决的问题。%There are mainly three kinds of catalysts used for producing N-phosphonomethyl glycine by air (oxygen) catalytic oxidation:activated carbon,noble metal and transition metal catalysts. The research progress of these catalysts and their relative merits for applications in N-phosphonomethyl glycine synthesis are summarized and analyzed in this paper. Activated carbon catalysts are low cost and can be simply prepared,but they possess short working life and leave too much formaldehyde as by-product. Noble metal catalysts have long operation life and the obtained product is high yield with good quality,but the catalysts are high cost and difficult to be prepared and regenerated. Transition metal catalysts belong to homogeneous catalysts and can be easily separated from products but with low yield. Hence,to address the domestic problems faced by glyphosate enterprises,catalysts,which are low cost,environmental friendly and easily prepared and regenerated,with high activities are urgently required.

  9. Olefin metathesis in air.

    Science.gov (United States)

    Piola, Lorenzo; Nahra, Fady; Nolan, Steven P

    2015-01-01

    Since the discovery and now widespread use of olefin metathesis, the evolution of metathesis catalysts towards air stability has become an area of significant interest. In this fascinating area of study, beginning with early systems making use of high oxidation state early transition metal centers that required strict exclusion of water and air, advances have been made to render catalysts more stable and yet more functional group tolerant. This review summarizes the major developments concerning catalytic systems directed towards water and air tolerance.

  10. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  11. Use catalytic combustion for LHV gases

    Energy Technology Data Exchange (ETDEWEB)

    Tucci, E.R.

    1982-03-01

    This paper shows how low heating value (LHV) waste gases can be combusted to recover energy even when the gases won't burn in a normal manner. Significant energy and economic savings can result by adopting this process. Catalytic combustion is a heterogeneous surface-catalyzed air oxidation of fuel, gaseous or liquid, to generate thermal energy in a flameless mode. The catalytic combustion process is quite complex since it involves numerous catalytic surface and gas-phase chemical reactions. During low temperature surface-catalyzed combustion, as in start-up, the combustion stage is under kinetically controlled conditions. The discussion covers the following topics - combustor substrates; combustor washcoating and catalyzing; combustor operational modes (turbine or tabular modes); applications in coal gasification and in-situ gasification; waste process gases. 16 refs.

  12. PREFACE: Wetting: introductory note

    Science.gov (United States)

    Herminghaus, S.

    2005-03-01

    The discovery of wetting as a topic of physical science dates back two hundred years, to one of the many achievements of the eminent British scholar Thomas Young. He suggested a simple equation relating the contact angle between a liquid surface and a solid substrate to the interfacial tensions involved [1], γlg cos θ = γsg - γsl (1) In modern terms, γ denotes the excess free energy per unit area of the interface indicated by its indices, with l, g and s corresponding to the liquid, gas and solid, respectively [2]. After that, wetting seems to have been largely ignored by physicists for a long time. The discovery by Gabriel Lippmann that θ may be tuned over a wide range by electrochemical means [3], and some important papers about modifications of equation~(1) due to substrate inhomogeneities [4,5] are among the rare exceptions. This changed completely during the seventies, when condensed matter physics had become enthusiastic about critical phenomena, and was vividly inspired by the development of the renormalization group by Kenneth Wilson [6]. This had solved the long standing problem of how to treat fluctuations, and to understand the universal values of bulk critical exponents. By inspection of the critical exponents of the quantities involved in equation~(1), John W Cahn discovered what he called critical point wetting: for any liquid, there should be a well-defined transition to complete wetting (i.e., θ = 0) as the critical point of the liquid is approached along the coexistence curve [7]. His paper inspired an enormous amount of further work, and may be legitimately viewed as the entrance of wetting into the realm of modern physics. Most of the publications directly following Cahn's work were theoretical papers which elaborated on wetting in relation to critical phenomena. A vast amount of interesting, and in part quite unexpected, ramifications were discovered, such as the breakdown of universality in thin film systems [8]. Simultaneously, a number

  13. Wetting and Minimal Surfaces

    CERN Document Server

    Bachas, C; Wiese, K J; Bachas, Constantin; Doussal, Pierre Le; Wiese, Kay Joerg

    2006-01-01

    We study minimal surfaces which arise in wetting and capillarity phenomena. Using conformal coordinates, we reduce the problem to a set of coupled boundary equations for the contact line of the fluid surface, and then derive simple diagrammatic rules to calculate the non-linear corrections to the Joanny-de Gennes energy. We argue that perturbation theory is quasi-local, i.e. that all geometric length scales of the fluid container decouple from the short-wavelength deformations of the contact line. This is illustrated by a calculation of the linearized interaction between contact lines on two opposite parallel walls. We present a simple algorithm to compute the minimal surface and its energy based on these ideas. We also point out the intriguing singularities that arise in the Legendre transformation from the pure Dirichlet to the mixed Dirichlet-Neumann problem.

  14. Catalytic distillation process

    Science.gov (United States)

    Smith, Jr., Lawrence A.

    1982-01-01

    A method for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C.sub.4 feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

  15. Catalytic Functions of Standards

    NARCIS (Netherlands)

    K. Blind (Knut)

    2009-01-01

    textabstractThe three different areas and the examples have illustrated several catalytic functions of standards for innovation. First, the standardisation process reduces the time to market of inventions, research results and innovative technologies. Second, standards themselves promote the diffusi

  16. Wetting front instability in an initially wet unsaturated fracture

    Energy Technology Data Exchange (ETDEWEB)

    Nicholl, M.J.; Glass, R.J.; Nguyen, H.A.

    1992-12-31

    Experimental results exploring gravity-driven wetting front instability in a pre-wetted, rough-walled analog fracture are presented. Initial conditions considered include a uniform moisture field wetted to field capacity of the analog fracture and the structured moisture field created by unstable infiltration into an initially dry fracture. As in previous studies performed under dry initial conditions, instability was found to result both at the cessation of stable infiltration and at flux lower than the fracture capacity under gravitational driving force. Individual fingers were faster, narrower, longer, and more numerous than observed under dry initial conditions. Wetting fronts were found to follow existing wetted structure, providing a mechanism for rapid recharge and transport.

  17. Fundamental Difficulties Associated With Underwater Wet Welding

    Directory of Open Access Journals (Sweden)

    Joshua E. Omajene,

    2014-06-01

    Full Text Available The offshore industries carry out welding activities in the wet environment. It is evident that the wet environments possess difficulties in carrying out underwater welding. Therefore there is the need to improve the quality of weld achieved in underwater welding. This paper investigates the difficulties associated with underwater welding. The objective of this research paper is to identify and analyze the different difficulties in underwater welding so as to make a clear background for further research to identifying the processes of eliminating these difficulties. The major difficulties in underwater welding are the cooling rate of the weld metal and arc stability during underwater wet welding at a higher depth. Methods of decreasing the cooling rate of weld metal and how to achieve arc stability are the major methods of approach. The result of welds achieved in underwater welding will be much improved as compared to air welding if the effects of the difficulties associated with underwater welding are eliminated. This will lead to a more robust welding activities being carried out underwater.

  18. Recycled High-Density Polyethylene and Rice Husk as a Wetted Pad in Evaporative Cooling System

    Directory of Open Access Journals (Sweden)

    Nitipong Soponpongpipat

    2011-01-01

    Full Text Available Problem statement: The low cost and easy-to-find materials, for being used as wetted pad of evaporative cooling system, are necessary for agriculture. This study, thus, studied the evaporative cooling efficiency and pressure drop of recycled High-Density Polyethylene (HDPE and rice husk as a wetted pad in evaporative cooling system. Approach: The study was done by establishing the tested wetted pad with 25.4 and 50.8 mm of thickness. The velocity air flow through wetted pad was controlled at 1, 2 and 3 m sec−1 respectively. In addition, the dry bulb and wet bulb temperatures of inlet air were controlled at 30.1 ± 1.0°C and 23.2 ± 1.1°C, respectively. The commercial wetted pad was also tested in order to compare results with rice husk and recycled HDPE. Results: It was found that rice husk wetted pad gave the average saturation efficiency of 55.9 %, while HDPE gave the average saturation efficiency of 29.1%. However, the pressure drop across wetted pad of rice husk and recycled HDPE was significantly higher than that of commercial wetted pad. For the effect of air velocity on saturation efficiency and pressure drop, it was found that higher air velocity decreased saturation efficiency and increased pressure drop across wetted pad. Conclusion: Finally, the rice husk has a potential as wetted pad material. However, further study about optimum point between operation cost and materials cost of using rice husk wetted pad is needed.

  19. Catalytic conversion of light alkanes

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.

    1992-06-30

    The second Quarterly Report of 1992 on the Catalytic Conversion of Light Alkanes reviews the work done between April 1, 1992 and June 31, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products that can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon uwspomdon fuel. During the past quarter we have continued to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. We continue to investigate three molecular environments for the active catalytic species that we are trying to generate: electron-deficient macrocycles (PHASE I), polyoxometallates (PHASE II), and regular oxidic lattices including zeolites and related structures as well as other molecular surface structures having metal oxo groups (PHASE I).

  20. Catalytic ignition of light hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    K. L. Hohn; C.-C. Huang; C. Cao

    2009-01-01

    Catalytic ignition refers to phenomenon where sufficient energy is released from a catalytic reaction to maintain further reaction without additional extemai heating. This phenomenon is important in the development of catalytic combustion and catalytic partial oxidation processes, both of which have received extensive attention in recent years. In addition, catalytic ignition studies provide experimental data which can be used to test theoretical hydrocarbon oxidation models. For these reasons, catalytic ignition has been frequently studied. This review summarizes the experimental methods used to study catalytic ignition of light hydrocarbons and describes the experimental and theoretical results obtained related to catalytic ignition. The role of catalyst metal, fuel and fuel concentration, and catalyst state in catalytic ignition are examined, and some conclusions are drawn on the mechanism of catalytic ignition.

  1. Catalytic Decomposition of Methylene Chloride by Sulfated Titania Catalysts

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Catalytic decomposition of methylene chloride in air below 300℃ was studied.Sulfated titania was very effective in converting 959ppm methylene chloride selectively to CO,CO2 and HCl.Complete decomposition of methylene chloride was achieved at low temperature(275℃).It was found that the acidic property of catalyst was a determinant factor for the catalytic activity.The presence of water vapor in the feed stream remarkably reduced the catalytic activity,which could be due to the blockage of acidic sites on the surface of catalyst by water molecules.A bifunctional catalyst comprising copper oxide was developed to improve the selectivity of catalytic oxidation,which indicated that copper oxide can promote the deep oxidation of methylene chloride.The crystal form of TiO2 imposes an important influence upon the catalytic oxidation.

  2. Water recovery by catalytic treatment of urine vapor

    Science.gov (United States)

    Budininkas, P.; Quattrone, P. D.; Leban, M. I.

    1980-01-01

    The objective of this investigation was to demonstrate the feasibility of water recovery on a man-rated scale by the catalytic processing of untreated urine vapor. For this purpose, two catalytic systems, one capable of processing an air stream containing low urine vapor concentrations and another to process streams with high urine vapor concentrations, were designed, constructed, and tested to establish the quality of the recovered water.

  3. Catalytic coherence transformations

    Science.gov (United States)

    Bu, Kaifeng; Singh, Uttam; Wu, Junde

    2016-04-01

    Catalytic coherence transformations allow the otherwise impossible state transformations using only incoherent operations with the aid of an auxiliary system with finite coherence that is not being consumed in any way. Here we find the necessary and sufficient conditions for the deterministic and stochastic catalytic coherence transformations between a pair of pure quantum states. In particular, we show that the simultaneous decrease of a family of Rényi entropies of the diagonal parts of the states under consideration is a necessary and sufficient condition for the deterministic catalytic coherence transformations. Similarly, for stochastic catalytic coherence transformations we find the necessary and sufficient conditions for achieving a higher optimal probability of conversion. We thus completely characterize the coherence transformations among pure quantum states under incoherent operations. We give numerous examples to elaborate our results. We also explore the possibility of the same system acting as a catalyst for itself and find that indeed self-catalysis is possible. Further, for the cases where no catalytic coherence transformation is possible we provide entanglement-assisted coherence transformations and find the necessary and sufficient conditions for such transformations.

  4. Investigations of VOx/SBA-15 catalytic performance in propane dehydrogenation with CO2

    OpenAIRE

    Ze?czak, Kamila; Michorczyk, Piotr; Ogonowski, Jan

    2011-01-01

    The catalytic activity of V-containing SBA-15 materials wereprepared by incipient wetness method and tested in propane dehydrogenation with carbon dioxide. It has been found that vanadium catalysts show relatively high catalytic activity and selectivity to propene. The highest activity exhibits the sample containing 5 wt. % of V. At temperature 823 K, propane conversion and propene selectivity were 26,7%, while 70 %, respectively.

  5. Facile Growth of Suspended SWNTs by Wet Catalyst Method

    Science.gov (United States)

    Jeong, G.-H.; Yamazaki, A.; Takagi, D.; Okuda, M.; Suzuki, S.; Yoshimura, H.; Kobayashi, Y.; Homma, Y.

    2005-03-01

    Nanosized wet catalysts have recently employed for the single-walled carbon nanotubes (SWNTs) growth with a uniform diameter, which is a key factor governing electronic properties of the SWNTs. Suspended SWNTs are useful for clarification of the physical/optical properties due to their interaction-free feature between substrate. For this reason, we tried to grow the diameter-controlled suspended SWNTs using pillar substrates and catalytic-metal containing organic molecules, which have refined catalyst size. Ferritin consisting of protein shell and encaging iron particles in its inner space and Co-filled apoferritin are utilized as a wet catalyst. By controlled experiments, SWNTs are successfully synthesized not only on flat substrates but also on Si-substrates with nanopillars. Low concentration of the ferritin gives the narrow diameter distribution of the SWNTs, which is confirmed by Raman spectroscopy. In addition, suspended SWNTs with narrow tube-diameter ranges are for the first time achieved using Co-filled aopferritins.

  6. Squeezing wetting and nonwetting liquids

    OpenAIRE

    Samoilov, V. N.; Persson, B. N. J.

    2004-01-01

    We present molecular-dynamics results for the squeezing of octane (C8H18) between two approaching solid elastic walls with different wetting properties. The interaction energy between the octane bead units and the solid walls is varied from a very small value (1 meV), corresponding to a nonwetting surface with a very large contact angle (nearly 180 degrees), to a high value (18.6 meV) corresponding to complete wetting. When at least one of the solid walls is wetted by octane we observe well d...

  7. Development studies of a novel wet oxidation process

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, T.W.; Dhooge, P.M. [Delphi Research, Inc., Albuquerque, NM (United States)

    1995-10-01

    Many DOE waste streams and remediates contain complex and variable mixtures of organic compounds, toxic metals, and radionuclides. These materials are often dispersed in organic or inorganic matrices, such as personal protective equipment, various sludges, soils, and water. Incineration and similar combustive processes do not appear to be viable options for treatment of these waste streams due to various considerations. The objective of this project is to develop a novel catalytic wet oxidation process for the treatment of multi-component wastes. The DETOX process uses a unique combination of metal catalysts to increase the rate of oxidation of organic materials.

  8. Fabrication of Core-Shell Structural SiO2@H3[PM12O40] Material and Its Catalytic Activity

    Directory of Open Access Journals (Sweden)

    Xin Yang

    2014-01-01

    Full Text Available Through a natural tree grain template and sol-gel technology, the heterogeneous catalytic materials based on polyoxometalate compounds H3[PM12O40] encapsulating SiO2: SiO2@H3[PM12O40] (SiO2@PM12, M = W, Mo with core-shell structure had been prepared. The structure and morphology of the core-shell microspheres were characterized by the XRD, IR spectroscopy, UV-Vis absorbance, and SEM. These microsphere materials can be used as heterogeneous catalysts with high activity and stability for catalytic wet air oxidation of pollutant dyes safranine T (ST at room condition. The results show that the catalysts have excellent catalytic activity in treatment of wastewater containing 10 mg/L ST, and 94% of color can be removed within 60 min. Under different cycling runs, it is shown that the catalysts are stable under such operating conditions and the leaching tests show negligible leaching effect owing to the lesser dissolution.

  9. Topographical Anisotropy and Wetting of Ground Stainless Steel Surfaces

    Directory of Open Access Journals (Sweden)

    Cornelia Bellmann

    2012-12-01

    Full Text Available Microscopic and physico-chemical methods were used for a comprehensive surface characterization of different mechanically modified stainless steel surfaces. The surfaces were analyzed using high-resolution confocal microscopy, resulting in detailed information about the topographic properties. In addition, static water contact angle measurements were carried out to characterize the surface heterogeneity of the samples. The effect of morphological anisotropy on water contact angle anisotropy was investigated. The correlation between topography and wetting was studied by means of a model of wetting proposed in the present work, that allows quantifying the air volume of the interface water drop-stainless steel surface.

  10. Performance characterization of a hydrogen catalytic heater.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry Alan; Kanouff, Michael P.

    2010-04-01

    This report describes the performance of a high efficiency, compact heater that uses the catalytic oxidation of hydrogen to provide heat to the GM Hydrogen Storage Demonstration System. The heater was designed to transfer up to 30 kW of heat from the catalytic reaction to a circulating heat transfer fluid. The fluid then transfers the heat to one or more of the four hydrogen storage modules that make up the Demonstration System to drive off the chemically bound hydrogen. The heater consists of three main parts: (1) the reactor, (2) the gas heat recuperator, and (3) oil and gas flow distribution manifolds. The reactor and recuperator are integrated, compact, finned-plate heat exchangers to maximize heat transfer efficiency and minimize mass and volume. Detailed, three-dimensional, multi-physics computational models were used to design and optimize the system. At full power the heater was able to catalytically combust a 10% hydrogen/air mixture flowing at over 80 cubic feet per minute and transfer 30 kW of heat to a 30 gallon per minute flow of oil over a temperature range from 100 C to 220 C. The total efficiency of the catalytic heater, defined as the heat transferred to the oil divided by the inlet hydrogen chemical energy, was characterized and methods for improvement were investigated.

  11. Rapid Deployment of Rich Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Richard S. Tuthill

    2004-06-10

    The overall objective of this research under the Turbines Program is the deployment of fuel flexible rich catalytic combustion technology into high-pressure ratio industrial gas turbines. The resulting combustion systems will provide fuel flexibility for gas turbines to burn coal derived synthesis gas or natural gas and achieve NO{sub x} emissions of 2 ppmvd or less (at 15 percent O{sub 2}), cost effectively. This advance will signify a major step towards environmentally friendly electric power generation and coal-based energy independence for the United States. Under Phase 1 of the Program, Pratt & Whitney (P&W) performed a system integration study of rich catalytic combustion in a small high-pressure ratio industrial gas turbine with a silo combustion system that is easily scalable to a larger multi-chamber gas turbine system. An implementation plan for this technology also was studied. The principal achievement of the Phase 1 effort was the sizing of the catalytic module in a manner which allowed a single reactor (rather than multiple reactors) to be used by the combustion system, a conclusion regarding the amount of air that should be allocated to the reaction zone to achieve low emissions, definition of a combustion staging strategy to achieve low emissions, and mechanical integration of a Ceramic Matrix Composite (CMC) combustor liner with the catalytic module.

  12. Development of Pillared Clays for Wet Hydrogen Peroxide Oxidation of Phenol and Its Application in the Posttreatment of Coffee Wastewater

    Directory of Open Access Journals (Sweden)

    Nancy R. Sanabria

    2012-01-01

    Full Text Available This paper focuses on the use of pillared clays as catalysts for the Fenton-like advanced oxidation, specifically wet hydrogen peroxide catalytic oxidation (WHPCO. This paper discusses the limitations on the application of a homogeneous Fenton system, development of solid catalysts for the oxidation of phenol, advances in the synthesis of pillared clays, and their potential application as catalysts for phenol oxidation. Finally, it analyzes the use of pillared clays as heterogeneous Fenton-like catalysts for a real wastewater treatment, emphasizing the oxidation of phenolic compounds present in coffee wastewater. Typically, the wet hydrogen peroxide catalytic oxidation in a real effluent system is used as pretreatment, prior to biological treatment. In the specific case of coffee wet processing wastewater, catalytic oxidation with pillared bentonite with Al-Fe is performed to supplement the biological treatment, that is, as a posttreatment system. According to the results of catalytic activity of pillared bentonite with Al-Fe for oxidation of coffee processing wastewater (56% phenolic compounds conversion, 40% selectivity towards CO2, and high stability of active phase, catalytic wet hydrogen peroxide oxidation emerges as a viable alternative for management of this type of effluent.

  13. Reentrant Wetting of Network Fluids

    Science.gov (United States)

    Bernardino, N. R.; Telo da Gama, M. M.

    2012-09-01

    We use a simple mesoscopic Landau-Safran theory of network fluids to show that a reentrant phase diagram, in the “empty liquid” regime, leads to nonmonotonic surface tension and reentrant wetting, as previously reported for binary mixtures. One of the wetting transitions is of the usual kind, but the low temperature transition may allow the display of the full range of fluctuation regimes predicted by renormalization group theory.

  14. Transport kinetics of wetting layers

    OpenAIRE

    Herminghaus, Stephan; Paatzsch, Thomas; Häcker, T.; Leiderer, Paul

    1995-01-01

    The transport kinetics of wetting layers of ethanol and propane on silver substrates is investigated by monitoring the temporal decay of pulsed-laser-induced spatial thickness modulations. Our method allows to distinguish between different transport mechanisms, such as direct exchange with the vapour phase, viscous flow within the wetting layer, or surface diffusion. In either ease, the activation energy found for the lateral transport points to viscous flow as the dominant mechanism in the i...

  15. Wetting film dynamics and stability

    OpenAIRE

    Radoev, B.; Stoeckelhuber, K. W.; Tsekov, R.; Letocart, P

    2011-01-01

    Although the wetting films are similar in many aspects to other thin liquid films, there are some differences in their behavior, too. In contrast to soap and emulsion films, whose surfaces are homogeneous, solid substrates of wetting films are heterogeneous as a rule, unless special measures for their homogenization are taken. Here we mean primarily heterogeneous distribution of surface energy leading to existence of hydrophobic domains on hydrophilic surfaces and vice versa. As is known, suc...

  16. Wetting of polymer covered surfaces

    OpenAIRE

    Halperin, A.; De Gennes, P.G.

    1986-01-01

    We consider solid surfaces, partly covered with flexible, neutral, linear polymers (by adsorption or by grafting), wetted by a liquid which is a good solvent of the poymer. We give formulae for the spreading coefficient S as a function of chain length, solvent quality and adsorption strength. We also discuss the wetting films obtained in spreading a droplet of (non volatile) solvent : the equilibrium thickness e of the film is a compromise between S (favouring thin films) and the coil entropi...

  17. Catalytic Conversion of Biofuels

    DEFF Research Database (Denmark)

    Jørgensen, Betina

    This thesis describes the catalytic conversion of bioethanol into higher value chemicals. The motivation has been the unavoidable coming depletion of the fossil resources. The thesis is focused on two ways of utilising ethanol; the steam reforming of ethanol to form hydrogen and the partial oxida...

  18. Catalytic Phosphination and Arsination

    Institute of Scientific and Technical Information of China (English)

    Kwong Fuk Yee; Chan Kin Shing

    2004-01-01

    The catalytic, user-friendly phosphination and arsination of aryl halides and triflates by triphenylphosphine and triphenylarsine using palladium catalysts have provided a facile synthesis of functionalized aryl phosphines and arsines in neutral media. Modification of the cynaoarisne yielded optically active N, As ligands which will be screened in various asymmetric catalysis.

  19. Catalytic efficiency of designed catalytic proteins.

    Science.gov (United States)

    Korendovych, Ivan V; DeGrado, William F

    2014-08-01

    The de novo design of catalysts that mimic the affinity and specificity of natural enzymes remains one of the Holy Grails of chemistry. Despite decades of concerted effort we are still unable to design catalysts as efficient as enzymes. Here we critically evaluate approaches to (re)design of novel catalytic function in proteins using two test cases: Kemp elimination and ester hydrolysis. We show that the degree of success thus far has been modest when the rate enhancements seen for the designed proteins are compared with the rate enhancements by small molecule catalysts in solvents with properties similar to the active site. Nevertheless, there are reasons for optimism: the design methods are ever improving and the resulting catalyst can be efficiently improved using directed evolution.

  20. Effects of carrier and Mn loading on supported manganese oxide catalysts for catalytic combustion of methane

    Institute of Scientific and Technical Information of China (English)

    Jinyan Hu; Wei Chu; Limin Shi

    2008-01-01

    Supported manganese oxide catalysts were prepared by incipient wetness impregnation method for methane cat-alytic combustion, and effects of the support (Al2O3, SiO2 and TiO2) and Mn loading were investigated. These catalysts were characterized with N2 adsorption, X-ray diffraction, X-ray photoelectron spectroscopy and temperature-programmed reduction techniques. Methane conversion varied in a large range depending on supports or Mn loading. Al2O3 supported 15% Mn cata-lyst exhibited better activity toward methane catalytic oxidation. The manganese state and oxygen species played an important role in the catalytic performance.

  1. 174 Reduction in Allergic Rhinitis Index by Decreasing Aero-Allergens and Malodor Causing Volatile Organic Compounds by Luna Air Purifiers Using Photo-Catalytic Oxidation (PCO) Technology

    OpenAIRE

    Ghosh, Nabarun; Aguaiza, Cristina; Guzman, Alicia; Chudasama, Jay; Bennert, Jeff; Das, A. B.

    2012-01-01

    Background The quality of the environment within buildings is a topic of major importance for public health. Breathing pure and clean air allows us to think more clearly, sleep more soundly, and stay healthier. Studies show that we receive 56% of our energy from the air we breathe, more than from water and food combined. On average we breathe 37 pounds of air a day. It has been established that the use of negative ions in a purification system is an effective means of eradicating aeroallergen...

  2. Wet sipping system at Wolsong-1

    International Nuclear Information System (INIS)

    After many years of operation, the on-power failed fuel detection and location systems along with alarm area gamma monitors at Wolsong-1 have successfully demonstrated that most, if not all, defective and suspect fuel bundles can be located before discharge to the fuel bay. Today, discharged bundles are now being transferred from the fuel bay to the AECL designed Modular Air-Cooled Storage (MACSTOR) canister facilities. Since these canisters are licensed for storing intact fuel bundles only, a procedure was needed at Wolsong-1 to separate any suspect or defective bundles that do not release fission products in detectable quantities. Therefore, KNF designed and built a wet sipper to enclose an irradiated bundle inside a sealed container at the bottom of the fuel bay. Various techniques were then used to enhance the release of water soluble fission products from defective fuel elements before circulating water samples from the immediate vicinity of an irradiated fuel bundle to an inspection station located at the top of the fuel bay. Any water samples with elevated levels of gamma activity were direct indications of a fuel cladding breach. The presence of defective fuel elements were then verified by visual inspection. The system performance test was performed in the Wolsong-1 nuclear power plant on March 2009.This paper describes the results of the wet sipping tests. (author)

  3. Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

    Science.gov (United States)

    Elliott, Douglas C; Oyler, James

    2013-12-17

    Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogenous catalyst for gasification.

  4. Catalytic Combustion Characteristics of H2/n-CaH10/Air Mixtures in Swiss-Roll Combustor%H2/n-C4H10/Air预混气在Swiss—roll燃烧器中的催化燃烧特性

    Institute of Scientific and Technical Information of China (English)

    杨帆; 钟北京

    2012-01-01

    In micro catalytic combustion, due to the competitive adsorption between fuel and oxygen molecular on the catalyst surface, the lower combustion limits are at the fuel rich condition. To enhance the utilization of fuel and enlarge the flammable range, hydrogen was added into the n-butane/air mixtures. Then catalytic combustion characteristics of H2/n-C4H10/air mixtures in Swiss-roll combustor were studied. Experimental results indicate that the addition of hydrogen and enlarge the flammable range of n-butane and the lower limits is fuel lean. Thus the utilization of fuel is high. The steady state combustion experiments show that the highest temperature of combustor is at fuel rich.%在微尺度催化燃烧中,由于燃料和氧气对于催化剂表面活性位的竞争,导致了可燃下限为富燃的情况。为了提高燃料利用率,拓宽可燃范围,本文在正丁烷/空气的混合气中加入一定量的氢气,在Swiss—roll燃烧器内研究了氯气/正丁烷/空气预混气的燃烧特性。结果表明,氢气能够有效拓宽正丁烷的可燃范围,可燃下限能够低于1,以贫燃的条件实现高燃料利用率。对于稳定燃烧温度的实验结果表明,燃烧器最高温度出现在富燃料一侧。

  5. A catalytic cracking process

    Energy Technology Data Exchange (ETDEWEB)

    Degnan, T.F.; Helton, T.E.

    1995-07-20

    Heavy oils are subjected to catalytic cracking in the absence of added hydrogen using a catalyst containing a zeolite having the structure of ZSM-12 and a large-pore crystalline zeolite having a Constraint Index less than about 1. The process is able to effect a bulk conversion of the oil at the same time yielding a higher octane gasoline and increased light olefin content. (author)

  6. Robust non-wetting PTFE surfaces by femtosecond laser machining.

    Science.gov (United States)

    Liang, Fang; Lehr, Jorge; Danielczak, Lisa; Leask, Richard; Kietzig, Anne-Marie

    2014-08-08

    Nature shows many examples of surfaces with extraordinary wettability,which can often be associated with particular air-trapping surface patterns. Here,robust non-wetting surfaces have been created by femtosecond laser ablation of polytetrafluoroethylene (PTFE). The laser-created surface structure resembles a forest of entangled fibers, which support structural superhydrophobicity even when the surface chemistry is changed by gold coating. SEM analysis showed that the degree of entanglement of hairs and the depth of the forest pattern correlates positively with accumulated laser fluence and can thus be influenced by altering various laser process parameters. The resulting fibrous surfaces exhibit a tremendous decrease in wettability compared to smooth PTFE surfaces; droplets impacting the virgin or gold coated PTFE forest do not wet the surface but bounce off. Exploratory bioadhesion experiments showed that the surfaces are truly air-trapping and do not support cell adhesion. Therewith, the created surfaces successfully mimic biological surfaces such as insect wings with robust anti-wetting behavior and potential for antiadhesive applications. In addition, the fabrication can be carried out in one process step, and our results clearly show the insensitivity of the resulting non-wetting behavior to variations in the process parameters,both of which make it a strong candidate for industrial applications.

  7. Robust Non-Wetting PTFE Surfaces by Femtosecond Laser Machining

    Directory of Open Access Journals (Sweden)

    Fang Liang

    2014-08-01

    Full Text Available Nature shows many examples of surfaces with extraordinary wettability, which can often be associated with particular air-trapping surface patterns. Here, robust non-wetting surfaces have been created by femtosecond laser ablation of polytetrafluoroethylene (PTFE. The laser-created surface structure resembles a forest of entangled fibers, which support structural superhydrophobicity even when the surface chemistry is changed by gold coating. SEM analysis showed that the degree of entanglement of hairs and the depth of the forest pattern correlates positively with accumulated laser fluence and can thus be influenced by altering various laser process parameters. The resulting fibrous surfaces exhibit a tremendous decrease in wettability compared to smooth PTFE surfaces; droplets impacting the virgin or gold coated PTFE forest do not wet the surface but bounce off. Exploratory bioadhesion experiments showed that the surfaces are truly air-trapping and do not support cell adhesion. Therewith, the created surfaces successfully mimic biological surfaces such as insect wings with robust anti-wetting behavior and potential for antiadhesive applications. In addition, the fabrication can be carried out in one process step, and our results clearly show the insensitivity of the resulting non-wetting behavior to variations in the process parameters, both of which make it a strong candidate for industrial applications.

  8. Olefin metathesis in air.

    Science.gov (United States)

    Piola, Lorenzo; Nahra, Fady; Nolan, Steven P

    2015-01-01

    Since the discovery and now widespread use of olefin metathesis, the evolution of metathesis catalysts towards air stability has become an area of significant interest. In this fascinating area of study, beginning with early systems making use of high oxidation state early transition metal centers that required strict exclusion of water and air, advances have been made to render catalysts more stable and yet more functional group tolerant. This review summarizes the major developments concerning catalytic systems directed towards water and air tolerance. PMID:26664625

  9. Olefin metathesis in air

    Directory of Open Access Journals (Sweden)

    Lorenzo Piola

    2015-10-01

    Full Text Available Since the discovery and now widespread use of olefin metathesis, the evolution of metathesis catalysts towards air stability has become an area of significant interest. In this fascinating area of study, beginning with early systems making use of high oxidation state early transition metal centers that required strict exclusion of water and air, advances have been made to render catalysts more stable and yet more functional group tolerant. This review summarizes the major developments concerning catalytic systems directed towards water and air tolerance.

  10. Olefin metathesis in air

    Science.gov (United States)

    Piola, Lorenzo; Nahra, Fady

    2015-01-01

    Summary Since the discovery and now widespread use of olefin metathesis, the evolution of metathesis catalysts towards air stability has become an area of significant interest. In this fascinating area of study, beginning with early systems making use of high oxidation state early transition metal centers that required strict exclusion of water and air, advances have been made to render catalysts more stable and yet more functional group tolerant. This review summarizes the major developments concerning catalytic systems directed towards water and air tolerance. PMID:26664625

  11. Squeezing wetting and nonwetting liquids.

    Science.gov (United States)

    Samoilov, V N; Persson, B N J

    2004-01-22

    We present molecular-dynamics results for the squeezing of octane (C8H18) between two approaching solid elastic walls with different wetting properties. The interaction energy between the octane bead units and the solid walls is varied from a very small value (1 meV), corresponding to a nonwetting surface with a very large contact angle (nearly 180 degrees), to a high value (18.6 meV) corresponding to complete wetting. When at least one of the solid walls is wetted by octane we observe well defined molecular layers develop in the lubricant film when the thickness of the film is of the order of a few atomic diameters. An external squeezing-pressure induces discontinuous, thermally activated changes in the number n of lubricant layers (n-->n-1 layering transitions). With increasing interaction energy between the octane bead units and the solid walls, the transitions from n to n-1 layers occur at higher average pressure. This results from the increasing activation barrier to nucleate the squeeze-out with increasing lubricant-wall binding energy (per unit surface area) in the contact zone. Thus, strongly wetting lubricant fluids are better boundary lubricants than the less wetting ones, and this should result in less wear. We analyze in detail the effect of capillary bridge formation (in the wetting case) and droplets formation (in the nonwetting case) on the forces exerted by the lubricant on the walls. For the latter case small liquid droplets may be trapped at the interface, resulting in a repulsive force between the walls during squeezing, until the solid walls come into direct contact, where the wall-wall interaction may be initially attractive. This effect is made use of in some practical applications, and we give one illustration involving conditioners for hair care application. PMID:15268334

  12. Why do pigeon feathers repel water? Hydrophobicity of pennae, Cassie-Baxter wetting hypothesis and Cassie-Wenzel capillarity-induced wetting transition.

    Science.gov (United States)

    Bormashenko, Edward; Bormashenko, Yelena; Stein, Tamir; Whyman, Gene; Bormashenko, Ester

    2007-07-01

    Wetting of pigeon feathers has been studied. It was demonstrated that the Cassie-Baxter wetting regime is inherent for pigeon pennae. The water drop, supported by network formed by barbs and barbules, sits partially on air pockets. Small static apparent angle hysteresis justifies the Cassie-Baxter wetting hypothesis. A twofold structure of a feather favors large contact angles and provides its water repellency. Cassie-Wenzel transition has been observed under drop evaporation, when drop radius becomes small enough for capillarity-induced water penetration into the protrusions, formed by barbules.

  13. Preparation and Use of a Room-Temperature Catalytic Converter

    Science.gov (United States)

    Wong, Gareth; Mark, Bernard; Chen, Xijia; Furch, Toran; Singmaster, K. A.; Wagenknecht, Paul S.

    2001-12-01

    A solid-state catalyst that effectively converts a CO/air mixture to CO2 at room temperature is readily prepared. The catalyst, which is composed of metallic gold on iron(III) oxide, is loaded into a simple flow cell to test its catalytic activity. Mixtures of CO and air are run through the catalyst and subsequently analyzed by gas-phase infrared spectroscopy to determine the effectiveness of the catalyst.

  14. Andreas Acrivos Dissertation Award: Onset of Dynamic Wetting Failure - The Mechanics of High-Speed Fluid Displacement

    Science.gov (United States)

    Vandre, Eric

    2014-11-01

    Dynamic wetting is crucial to processes where a liquid displaces another fluid along a solid surface, such as the deposition of a coating liquid onto a moving substrate. Dynamic wetting fails when process speed exceeds some critical value, leading to incomplete fluid displacement and transient phenomena that impact a variety of applications, such as microfluidic devices, oil-recovery systems, and splashing droplets. Liquid coating processes are particularly sensitive to wetting failure, which can induce air entrainment and other catastrophic coating defects. Despite the industrial incentives for careful control of wetting behavior, the hydrodynamic factors that influence the transition to wetting failure remain poorly understood from empirical and theoretical perspectives. This work investigates the fundamentals of wetting failure in a variety of systems that are relevant to industrial coating flows. A hydrodynamic model is developed where an advancing fluid displaces a receding fluid along a smooth, moving substrate. Numerical solutions predict the onset of wetting failure at a critical substrate speed, which coincides with a turning point in the steady-state solution path for a given set of system parameters. Flow-field analysis reveals a physical mechanism where wetting failure results when capillary forces can no longer support the pressure gradients necessary to steadily displace the receding fluid. Novel experimental systems are used to measure the substrate speeds and meniscus shapes associated with the onset of air entrainment during wetting failure. Using high-speed visualization techniques, air entrainment is identified by the elongation of triangular air films with system-dependent size. Air films become unstable to thickness perturbations and ultimately rupture, leading to the entrainment of air bubbles. Meniscus confinement in a narrow gap between the substrate and a stationary plate is shown to delay air entrainment to higher speeds for a variety of

  15. Wet deposition in the northeastern United States

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J; Mohnen, V; Kadlecek, J

    1980-12-01

    Attempts are made to examine concentration and wet deposition of pollutant material at selected stations within the northeastern United States and to characterize as many events as possible with respect to air mass origin. Further attempts are made to develop a regional pattern for the deposition of dominant ion species. MAP3S (US Multistate Atmospheric Power Production Pollution Study) data for 1977 to 1979 are used to determine concentration and deposition on an event basis from which monthly, seasonal, annual, and cumulative averages are developed. The ARL-ATAD trajectory model is used to characterize individual events as to air mass origin. Case studies are examined to illustrate variability in the chemical composition of precipitation originating from distinctly different air mass trajectories. A difference in concentration of pollution-related ions in precipitation is noted between Midwest/Ohio Valley and Great Lakes/Canadian air mass origins for carefully selected cases. Total deposition of the major ions is examined in an effort to develop a regional pattern for deposition over a period of at least one year. For that purpose, total deposition is normalized to remove the variability in precipitation amounts for inter-station comparison. No marked gradient is noted in the normalized deposition totals within the northeast of the United States. The Adirondack region exhibited the lowest normalized ion deposition value, while the Illinois station showed the highest of the MAP3S network. The data analysis suggest that the acid rain phenomena covers the entire northeast. The concept of large scale mixing emerges to account for the lack of a significant gradient in the normalized deposition.

  16. Inhibiting Wet Oxidation of Ammonia

    Science.gov (United States)

    Onisko, D. B. L.

    1985-01-01

    Simple modification of wet-oxidation process for treating organicwaste reduces loss of fixed nitrogen, potentially valuable byproduct of process. Addition of sufficient sulfuric acid to maintain reaction pH below 3 greatly reduces oxidation of ammonia to free nitrogen. No equipment modification required.

  17. IDENTIFICATION AND RESPONSES TO POTENTIAL EFFECTS OF SCR AND WET SCRUBBERS ON SUBMICRON PARTICULATE EMISSIONS AND PLUME CHARACTERISTICS

    Science.gov (United States)

    Applications of selective catalytic reduction (SCR) systems and wet flue gas desulfurization (FGD) scrubbers on coal-fired boilers have led to substantial reductions in emissions of nitrogen oxides (NOX) and sulfur dioxide (SO2). However, observations of pilot- and full-scale tes...

  18. Catalytic pyrolysis of olive mill wastewater sludge

    Science.gov (United States)

    Abdellaoui, Hamza

    From 2008 to 2013, an average of 2,821.4 kilotons/year of olive oil were produced around the world. The waste product of the olive mill industry consists of solid residue (pomace) and wastewater (OMW). Annually, around 30 million m3 of OMW are produced in the Mediterranean area, 700,000 m3 year?1 in Tunisia alone. OMW is an aqueous effluent characterized by an offensive smell and high organic matter content, including high molecular weight phenolic compounds and long-chain fatty acids. These compounds are highly toxic to micro-organisms and plants, which makes the OMW a serious threat to the environment if not managed properly. The OMW is disposed of in open air evaporation ponds. After evaporation of most of the water, OMWS is left in the bottom of the ponds. In this thesis, the effort has been made to evaluate the catalytic pyrolysis process as a technology to valorize the OMWS. The first section of this research showed that 41.12 wt. % of the OMWS is mostly lipids, which are a good source of energy. The second section proved that catalytic pyrolysis of the OMWS over red mud and HZSM-5 can produce green diesel, and 450 °C is the optimal reaction temperature to maximize the organic yields. The last section revealed that the HSF was behind the good fuel-like properties of the OMWS catalytic oils, whereas the SR hindered the bio-oil yields and quality.

  19. Low-temperature gas from marine shales: wet gas to dry gas over experimental time

    OpenAIRE

    Jarvie Daniel M; Mango Frank D

    2009-01-01

    Abstract Marine shales exhibit unusual behavior at low temperatures under anoxic gas flow. They generate catalytic gas 300° below thermal cracking temperatures, discontinuously in aperiodic episodes, and lose these properties on exposure to trace amounts of oxygen. Here we report a surprising reversal in hydrocarbon generation. Heavy hydrocarbons are formed before light hydrocarbons resulting in wet gas at the onset of generation grading to dryer gas over time. The effect is moderate under ga...

  20. Novel Catalytic Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Stuart Nemser, PhD

    2010-10-01

    There are many industrial catalytic organic reversible reactions with amines or alcohols that have water as one of the products. Many of these reactions are homogeneously catalyzed. In all cases removal of water facilitates the reaction and produces more of the desired chemical product. By shifting the reaction to right we produce more chemical product with little or no additional capital investment. Many of these reactions can also relate to bioprocesses. Given the large number of water-organic compound separations achievable and the ability of the Compact Membrane Systems, Inc. (CMS) perfluoro membranes to withstand these harsh operating conditions, this is an ideal demonstration system for the water-of-reaction removal using a membrane reactor. Enhanced reaction synthesis is consistent with the DOE objective to lower the energy intensity of U.S. industry 25% by 2017 in accord with the Energy Policy Act of 2005 and to improve the United States manufacturing competitiveness. The objective of this program is to develop the platform technology for enhancing homogeneous catalytic chemical syntheses.

  1. Underwater sustainability of the "Cassie" state of wetting.

    Science.gov (United States)

    Bobji, Musuvathi S; Kumar, S Vijay; Asthana, Ashish; Govardhan, Raghuraman N

    2009-10-20

    A rough hydrophobic surface when immersed in water can result in a "Cassie" state of wetting in which the water is in contact with both the solid surface and the entrapped air. The sustainability of the entrapped air on such surfaces is important for underwater applications such as reduction of flow resistance in microchannels and drag reduction of submerged bodies such as hydrofoils. We utilize an optical technique based on total internal reflection of light at the water-air interface to quantify the spatial distribution of trapped air on such a surface and its variation with immersion time. With this technique, we evaluate the sustainability of the Cassie state on hydrophobic surfaces with four different kinds of textures. The textures studied are regular arrays of pillars, ridges, and holes that were created in silicon by a wet etching technique, and also a texture of random craters that was obtained through electrodischarge machining of aluminum. These surfaces were rendered hydrophobic with a self-assembled layer of fluorooctyl trichlorosilane. Depending on the texture, the size and shape of the trapped air pockets were found to vary. However, irrespective of the texture, both the size and the number of air pockets were found to decrease with time gradually and eventually disappear, suggesting that the sustainability of the "Cassie" state is finite for all the microstructures studied. This is possibly due to diffusion of air from the trapped air pockets into the water. The time scale for disappearance of air pockets was found to depend on the kind of microstructure and the hydrostatic pressure at the water-air interface. For the surface with a regular array of pillars, the air pockets were found to be in the form of a thin layer perched on top of the pillars with a large lateral extent compared to the spacing between pillars. For other surfaces studied, the air pockets are smaller and are of the same order as the characteristic length scale of the texture

  2. WET SOLIDS FLOW ENHANCEMENT; FINAL

    International Nuclear Information System (INIS)

    The yield locus, tensile strength and fracture mechanisms of wet granular materials were studied. The yield locus of a wet material was shifted to the left of that of the dry specimen by a constant value equal to the compressive isostatic stress due to pendular bridges. for materials with straight yield loci, the shift was computed from the uniaxial tensile strength, either measured in a tensile strength tester or calculated from the correlation, and the angle of internal friction of the material. The predicted shift in the yield loci due to different moisture contents compare well with the measured shift in the yield loci of glass beads, crushed limestone, super D catalyst and Leslie coal. Measurement of the void fraction during the shear testing was critical to obtain the correct tensile strength theoretically or experimentally

  3. Gold-Copper Nanoparticles: Nanostructural Evolution and Bifunctional Catalytic Sites

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Jun; Shan, Shiyao; Yang, Lefu; Mott, Derrick; Malis, Oana; Petkov, Valeri; Cai, Fan; Ng, Mei; Luo, Jin; Chen, Bing H.; Engelhard, Mark H.; Zhong, Chuan-Jian

    2012-12-12

    Understanding of the atomic-scale structure is essential for exploiting the unique catalytic properties of any nanoalloy catalyst. This report describes novel findings of an investigation of the nanoscale alloying of gold-copper (AuCu) nanoparticles and its impact on the surface catalytic functions. Two pathways have been explored for the formation of AuCu nanoparticles of different compositons, including wet chemical synthesis from mixed Au- and Cu-precursor molecules, and nanoscale alloying via an evolution of mixed Au- and Cu-precursor nanoparticles near the nanoscale melting temperatures. For the evolution of mixed precursor nanoparticles, synchrotron x-ray based in-situ real time XRD was used to monitor the structural changes, revealing nanoscale alloying and reshaping towards an fcc-type nanoalloy (particle or cube) via a partial melting–resolidification mechanism. The nanoalloys supported on carbon or silica were characterized by in-situ high-energy XRD/PDFs, revealing an intriguing lattice "expanding-shrinking" phenomenon depending on whether the catalyst is thermochemically processed under oxidative or reductive atmosphere. This type of controllable structural changes is found to play an important role in determining the catalytic activity of the catalysts for carbon monoxide oxidation reaction. The tunable catalytic activities of the nanoalloys under thermochemically oxidative and reductive atmospheres are also discussed in terms of the bifunctional sites and the surface oxygenated metal species for carbon monoxide and oxygen activation.

  4. Wetting hysteresis induced by nanodefects.

    Science.gov (United States)

    Giacomello, Alberto; Schimmele, Lothar; Dietrich, Siegfried

    2016-01-19

    Wetting of actual surfaces involves diverse hysteretic phenomena stemming from ever-present imperfections. Here, we clarify the origin of wetting hysteresis for a liquid front advancing or receding across an isolated defect of nanometric size. Various kinds of chemical and topographical nanodefects, which represent salient features of actual heterogeneous surfaces, are investigated. The most probable wetting path across surface heterogeneities is identified by combining, within an innovative approach, microscopic classical density functional theory and the string method devised for the study of rare events. The computed rugged free-energy landscape demonstrates that hysteresis emerges as a consequence of metastable pinning of the liquid front at the defects; the barriers for thermally activated defect crossing, the pinning force, and hysteresis are quantified and related to the geometry and chemistry of the defects allowing for the occurrence of nanoscopic effects. The main result of our calculations is that even weak nanoscale defects, which are difficult to characterize in generic microfluidic experiments, can be the source of a plethora of hysteretical phenomena, including the pinning of nanobubbles. PMID:26721395

  5. Wetting hysteresis induced by nanodefects.

    Science.gov (United States)

    Giacomello, Alberto; Schimmele, Lothar; Dietrich, Siegfried

    2016-01-19

    Wetting of actual surfaces involves diverse hysteretic phenomena stemming from ever-present imperfections. Here, we clarify the origin of wetting hysteresis for a liquid front advancing or receding across an isolated defect of nanometric size. Various kinds of chemical and topographical nanodefects, which represent salient features of actual heterogeneous surfaces, are investigated. The most probable wetting path across surface heterogeneities is identified by combining, within an innovative approach, microscopic classical density functional theory and the string method devised for the study of rare events. The computed rugged free-energy landscape demonstrates that hysteresis emerges as a consequence of metastable pinning of the liquid front at the defects; the barriers for thermally activated defect crossing, the pinning force, and hysteresis are quantified and related to the geometry and chemistry of the defects allowing for the occurrence of nanoscopic effects. The main result of our calculations is that even weak nanoscale defects, which are difficult to characterize in generic microfluidic experiments, can be the source of a plethora of hysteretical phenomena, including the pinning of nanobubbles.

  6. Wet water glass production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake. The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

  7. 77 FR 3966 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Regional Haze

    Science.gov (United States)

    2012-01-26

    ... selective catalytic reduction (SCR) for NO X control and wet scrubbers to limit SO 2 emissions from both... to add selective non-catalytic reduction (SNCR) in 2012 to reduce NO X emissions and flue gas... scrubber and fabric filter at Edwards unit 3. Company-wide reductions from Ameren EGUs are projected to...

  8. Removal efficiencies of PCDDs/PCDFs by air pollution control devices in municipal solid waste incinerators.

    Science.gov (United States)

    Kim, S C; Jeon, S H; Jung, I R; Kim, K H; Kwon, M H; Kim, J H; Yi, J H; Kim, S J; You, J C; Jung, D H

    2001-01-01

    Removal efficiencies of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) by air pollution control devices (APCDs) in the commercial-scale municipal solid waste (MSW) incinerators with a capacity of above 200 ton/day were evaluated. The removal efficiencies of PCDDs/PCDFs were up to 95% when the activated carbon (AC) was injected in front of electrostatic precipitator (EP). Spray dryer absorber/bag filter (SDA/BF) had high removal efficiency (99%)) of PCDDs/PCDFs when a mixture of lime and AC was sprayed into the SDA. When the AC was not added in scrubbing solution, the whole congeners of PCDDs/PCDFs were enriched in the wet scrubber (WS) with negative removal efficiencies of -25% to -5731%. Discharge of PCDDs/PCDFs was decreased with increasing the proportions of AC added in scrubbing solution. Selective catalytic reduction (SCR) system had the removal efficiencies of up to 93% during the test operation.

  9. HYDROGEN TRANSFER IN CATALYTIC CRACKING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Hydrogen transfer is an important secondary reaction of catalytic cracking reactions, which affects product yield distribution and product quality. It is an exothermic reaction with low activation energy around 43.3 kJ/mol. Catalyst properties and operation parameters in catalytic cracking greatly influence the hydrogen transfer reaction. Satisfactory results are expected through careful selection of proper catalysts and operation conditions.

  10. Full scale calcium bromide injection with subsequent mercury oxidation and removal within wet flue gas desulphurization system: Experience at a 700 MW coal-fired power facility

    Science.gov (United States)

    Berry, Mark Simpson

    The Environmental Protection Agency promulgated the Mercury and Air Toxics Standards rule, which requires that existing power plants reduce mercury emissions to meet an emission rate of 1.2 lb/TBtu on a 30-day rolling average and that new plants meet a 0.0002 lb/GWHr emission rate. This translates to mercury removals greater than 90% for existing units and greater than 99% for new units. Current state-of-the-art technology for the control of mercury emissions uses activated carbon injected upstream of a fabric filter, a costly proposition. For example, a fabric filter, if not already available, would require a 200M capital investment for a 700 MW size unit. A lower-cost option involves the injection of activated carbon into an existing cold-side electrostatic precipitator. Both options would incur the cost of activated carbon, upwards of 3M per year. The combination of selective catalytic reduction (SCR) reactors and wet flue gas desulphurization (wet FGD) systems have demonstrated the ability to substantially reduce mercury emissions, especially at units that burn coals containing sufficient halogens. Halogens are necessary for transforming elemental mercury to oxidized mercury, which is water-soluble. Plants burning halogen-deficient coals such as Power River Basin (PRB) coals currently have no alternative but to install activated carbon-based approaches to control mercury emissions. This research consisted of investigating calcium bromide addition onto PRB coal as a method of increasing flue gas halogen concentration. The treated coal was combusted in a 700 MW boiler and the subsequent treated flue gas was introduced into a wet FGD. Short-term parametric and an 83-day longer-term tests were completed to determine the ability of calcium bromine to oxidize mercury and to study the removal of the mercury in a wet FGD. The research goal was to show that calcium bromine addition to PRB coal was a viable approach for meeting the Mercury and Air Toxics Standards rule

  11. Soil aeration status in a lowland wet grassland

    Science.gov (United States)

    Barber, K. R.; Leeds-Harrison, P. B.; Lawson, C. S.; Gowing, D. J. G.

    2004-02-01

    The maintenance or development of plant community diversity in species-rich wet grasslands has been a focus of water management considerations in the UK for the past 20 years. Much attention has been given to the control of water levels in the ditch systems within these wet grassland systems. In this paper we report measurements of aeration status and water-table fluctuation made on a peat soil site at Tadham Moor in Somerset, UK, where water management has focused on the maintenance of wet conditions that often result in flooding in winter and wet soil conditions in the spring and summer. Measurement and modelling of the water-table fluctuation indicates the possibility of variability in the aeration of the root environment and anoxic conditions for much of the winter period and for part of the spring and summer. We have used water content and redox potential measurements to characterize the aeration status of the peat soil. We find that air-filled porosity is related to water-table depth in these situations. Redox potentials in the spring were generally found to be low, implying a reducing condition for nitrate and iron. A significant relationship (p < 0.01) between redox potential and water-table depth exists for data measured at 0.1 m depth, but no relationship could be found for data from 0.4 m depth.

  12. Two-Phase Flow Simulation of Heat Exchanger of Wet Enthalpy Recycling Energy-Saving Fresh Air Condition%回收湿焓的新风换气节能空调换热部件的两相流模拟

    Institute of Scientific and Technical Information of China (English)

    朱冬生; 区志江; 蒋翔

    2012-01-01

    This paper focus on wet enthalpy recycling energy-saving fresh air condition.Established a computational model of corrugated plate evaporative condenser base on the volume of fluid(VOF) method.Using this model,this paper simulated and analyzed the influence factors of the plate heat transfer performance,such as heat flux density,water inlet temperature,water spray,gas inlet velocity and plate spacing.Results show that:the effects of heat flux on the wall temperature and gas-liquid interface temperature is linear;in the same heat flux,the interface temperature be reduced accordingly with the spray density increases;increasing gas flow rate or reducing the plate space can play the role of enhancing heat transfer.%本文着眼于一种回收湿焓的新风换气节能空调,基于Volume of Fluid算法,建立其核心换热部件波纹板换热器板外两相流传热传质的计算模型,并利用该模型模拟分析了壁面热流密度、喷淋水入口温度、喷淋水量、气相进口速度及板间距等因素对板外传热性能的影响。结果表明:热流密度对壁面温度、两相界面温度的影响是线性的;壁面热流密度增大、冷却水喷淋密度减小、气相进口速度提高、板间距减小对传热传质效果具有强化作用。

  13. Wet deposition of poly- and perfluorinated compounds in Northern Germany

    Energy Technology Data Exchange (ETDEWEB)

    Dreyer, Annekatrin, E-mail: annekatrin.dreyer@gkss.d [GKSS Research Centre, Institute for Coastal Research, Max Planck Str. 1, 21502 Geesthacht (Germany); Matthias, Volker; Weinberg, Ingo; Ebinghaus, Ralf [GKSS Research Centre, Institute for Coastal Research, Max Planck Str. 1, 21502 Geesthacht (Germany)

    2010-05-15

    Twenty precipitation samples were taken concurrently with air samples at a northern German monitoring site over a period of 7 months in 2007 and 2008. Thirty four poly- and perfluorinated compounds (PFC) were determined in rain water samples by solid phase extraction and HPLC-MS/MS analysis. Seventeen compounds were detected in rain water with SIGMAPFC concentrations ranging from 1.6 ng L{sup -1} to 48.6 ng L{sup -1}. Perfluorooctanoate (PFOA) and perfluorobutanate (PFBA) were the compounds that were usually observed in highest concentrations. Calculated SIGMAPFC deposition rates were between 2 and 91 ng m{sup -2} d{sup -1}. These findings indicate that particle phase PFC are deposited from the atmosphere by precipitation. A relationship between PFC wet deposition and air concentration may be established via precipitation amounts. Trajectory analysis revealed that PFC concentration and deposition estimates in precipitation can only be explained if a detailed air mass history is considered. - Information on air mass history, meteorological conditions, and distribution of PFC sources is necessary to understand and estimate PFC concentrations and wet deposition.

  14. Bifunctional catalytic electrode

    Science.gov (United States)

    Cisar, Alan (Inventor); Murphy, Oliver J. (Inventor); Clarke, Eric (Inventor)

    2005-01-01

    The present invention relates to an oxygen electrode for a unitized regenerative hydrogen-oxygen fuel cell and the unitized regenerative fuel cell having the oxygen electrode. The oxygen electrode contains components electrocatalytically active for the evolution of oxygen from water and the reduction of oxygen to water, and has a structure that supports the flow of both water and gases between the catalytically active surface and a flow field or electrode chamber for bulk flow of the fluids. The electrode has an electrocatalyst layer and a diffusion backing layer interspersed with hydrophilic and hydrophobic regions. The diffusion backing layer consists of a metal core having gas diffusion structures bonded to the metal core.

  15. Catalytic quantum error correction

    CERN Document Server

    Brun, T; Hsieh, M H; Brun, Todd; Devetak, Igor; Hsieh, Min-Hsiu

    2006-01-01

    We develop the theory of entanglement-assisted quantum error correcting (EAQEC) codes, a generalization of the stabilizer formalism to the setting in which the sender and receiver have access to pre-shared entanglement. Conventional stabilizer codes are equivalent to dual-containing symplectic codes. In contrast, EAQEC codes do not require the dual-containing condition, which greatly simplifies their construction. We show how any quaternary classical code can be made into a EAQEC code. In particular, efficient modern codes, like LDPC codes, which attain the Shannon capacity, can be made into EAQEC codes attaining the hashing bound. In a quantum computation setting, EAQEC codes give rise to catalytic quantum codes which maintain a region of inherited noiseless qubits. We also give an alternative construction of EAQEC codes by making classical entanglement assisted codes coherent.

  16. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  17. ZnO/MoO 3 mixed oxide nanotube: A highly efficient and stable catalyst for degradation of dye by air under room conditions

    Science.gov (United States)

    Huang, Jiguo; Wang, Xiaohong; Li, Sen; Wang, Yu

    2010-10-01

    As a continuation of our work to develop catalysts with high activity for catalytic air wet oxidation process under mild conditions, degradation of wastewater containing 0.3 g/L Safranin-T (ST) by air oxidation over ZnO/MoO 3 nanotube catalyst was studied. It was found the decolorization efficiency and the chemical oxygen demand (COD) removal of ST reached above 98% and 95%, respectively, within 18 min at room temperature and atmospheric pressure. And the organic pollutants were totally mineralized to simple inorganic species such as HCO 3-, Cl - and NO 3-, while the total organic carbon (TOC) decreased 99.3%. The structure and morphology of the catalyst after ten cycling runs showed that the catalyst was stable under such operating condition and the leaching test showed negligible leaching effect. This ZnO/MoO 3 nanotube is proved to be an active and stable heterogeneous catalyst in CWAO of ST under extremely mild conditions.

  18. Unsteady catalytic processes and sorption-catalytic technologies

    International Nuclear Information System (INIS)

    Catalytic processes that occur under conditions of the targeted unsteady state of the catalyst are considered. The highest efficiency of catalytic processes was found to be ensured by a controlled combination of thermal non-stationarity and unsteady composition of the catalyst surface. The processes based on this principle are analysed, in particular, catalytic selective reduction of nitrogen oxides, deep oxidation of volatile organic impurities, production of sulfur by the Claus process and by hydrogen sulfide decomposition, oxidation of sulfur dioxide, methane steam reforming and anaerobic combustion, selective oxidation of hydrocarbons, etc.

  19. Unsteady catalytic processes and sorption-catalytic technologies

    Energy Technology Data Exchange (ETDEWEB)

    Zagoruiko, A N [G.K. Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2007-07-31

    Catalytic processes that occur under conditions of the targeted unsteady state of the catalyst are considered. The highest efficiency of catalytic processes was found to be ensured by a controlled combination of thermal non-stationarity and unsteady composition of the catalyst surface. The processes based on this principle are analysed, in particular, catalytic selective reduction of nitrogen oxides, deep oxidation of volatile organic impurities, production of sulfur by the Claus process and by hydrogen sulfide decomposition, oxidation of sulfur dioxide, methane steam reforming and anaerobic combustion, selective oxidation of hydrocarbons, etc.

  20. NiMo/Al{sub 2}O{sub 3}-MgO (x) catalysts. The effect of the prolonged exposure to ambient air on the textural and catalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Solis, D.; Klimova, T.; Ramirez, J. [Departamento de Ingenieria Quimica, Facultad de Quimica, UNAM. Cd. Universitaria,, Coyoacan (Mexico); Cortez, T. [Instituto Mexicano del Petroleo, Tratamiento de Crudo Maya, Eje central Lazaro Cardenas 152, Col. San Bartolo Atepehuacan, C.P. (Mexico)

    2004-11-24

    In the search to obtain stable catalysts for selective elimination of sulfur from gasoline, maintaining octane number, NiMo catalysts supported on Al-Mg mixed oxides were prepared by the sol-gel method and evaluated after 6-month storage in contact with ambient air, the results were compared with the freshly prepared samples. Both, freshly prepared and aged samples were characterized by nitrogen physisorption measurements (S{sub BET}), infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRD) and high-resolution electron microscopy (HREM), they were tested in the thiophene hydrodesulfurization reaction.The results indicate that the incorporation of small amounts of magnesia (5mol%) into the alumina support, leads to the catalyst with low hydrogenation function and appropriate stability during prolonged contact with ambient conditions.

  1. Transformations in oil shale ash at wet deposition

    International Nuclear Information System (INIS)

    Estonian oil shale ash contains chemically active compounds which would undergo different spontaneous transformations in the atmosphere of air. For explaining these processes the system ash-water-air was studied storing moisture samples of ash in laboratory in open-air as well as hermetic conditions. The samples of dry ash formed at pulverized combustion of oil shale at the Baltic Power Plant, and samples obtained from ash storing plateau from different depth of different boreholes were under investigation. Storing conditions as well as the properties of initial samples have a great influence upon the processes taking place at storing of ashes. The results obtained could be used to explain and control the processes taking place at storing of ashes under atmospheric (wet) conditions

  2. Coal combustion by wet oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.

    1980-11-15

    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  3. Increasing heat stress relief produced by coupled coat wetting and forced ventilation.

    Science.gov (United States)

    Berman, A

    2008-12-01

    Coupling repeated wetting of the coat and forced ventilation is most efficient in removing heat stress in more humid climates. The procedure was initiated approximately 24 yr ago and is widely used, but the impact of air velocity on the efficiency of heat stress relief has not been examined. This study examined the feasibility of using surface temperature for real-time estimation of heat stress relief. It was carried out in midsummer in Israel on 6 mature lactating Holsteins. A 15 x 15 cm area on the right side of the body was thoroughly wetted. Hair surface and skin temperature on the wetted area and adjacent dry area were measured at 1-min intervals for 15 min while air movement was less than 0.1 m/s, and the sequence was repeated with air velocities of 0.5 to 3 m/s perpendicular to the body surface. Because the cooled surface was small, the response to cooling was local. In 3 animals, the whole left side of the body also was wetted and exposed to forced ventilation (1.5 m/s) to combine local cooling with larger body surface cooling. The air temperature was 29.5 +/- 0.05 degrees C, and the relative humidity was 56.7 +/- 0.2%. Rectal temperature and respiratory frequency indicated minor heat stress. Mean wet hair surface temperature (Thw) and wet skin temperature were 2.1 and 1.5 degrees C lower than the respective dry hair surface temperature (Thd) and dry skin temperature. At an air velocity of 0.5 m/s, Thw was practically identical to that in still air and to Thd. At greater air velocities, Thw decreased immediately after wetting, and minimal values were reached within 1 min, were maintained for 6 to 7 min after wetting, and reached 95% of the mean Thd value by 8 and 11 min after wetting at 1 and 2 m/s, respectively. Wetting the coat had the potential to reduce Thd temperature by 10 to 11 degrees C. The relatively small difference between Thd and Thw probably is due to heat flow from the body. The latter was estimated by comparing enthalpies at Thd, at Thw, and

  4. Microwave assisted wet oxidation of p-nitrophenol

    Institute of Scientific and Technical Information of China (English)

    BO; Longli; CHEN; Shuo; QUAN; Xie; LIU; Xitao; ZHAO; Huimin

    2005-01-01

    Aqueous solution of p-nitrophenol (PNP) was treated continuously by microwave assisted wet oxidation while flowing through a granular activated carbon (GAC) fixed bed. PNP was pre-adsorbed onto GAC prior to being put into the reactor so as to prevent PNP adsorption on GAC during microwave irradiation. PNP solutions with different initial concentration (218.6 mg/L and 1200 mg/L) were treated under conditions of microwave power 500 W, liquid flow 6.4 mL/min and air flow 40 mL/min or 60 mL/min. The results indicated that the removal of PNP was higher than 90% and more than 65% PNP was mineralized. Phenol, nitrobenzene, hydroquinone and benzoquinone occurred as course products during the operation process, which were degraded further. The biodegradability of the outflow was improved greatly by microwave assisted wet oxidation.

  5. Indicators of changing landscape wetness in the western Canadian Arctic

    Science.gov (United States)

    Marsh, P.; de Jong, T.; Walker, B.

    2015-12-01

    The landscape of the western Canadian arctic has been changing over the last 5 decades in response to warming air temperatures and decreasing precipitation. Changes include thinner snowcover, decreased river and lake ice thickness, deepening active layer, increasing thaw slumping, and expanding shrub cover for example. Although there are no long term data sets to consider changes in soil wetness in this region, changes in surface moisture can be considered through analysis of both long term stream discharge records and remote sensing of tundra ponds and lakes. In this paper, we will use these long term records in order to explore past changes to this environment. In addition, we will outline details of ongoing observations at long term observatories and modelling efforts to consider the controls on future changes in wetness.

  6. Single-metalloprotein wet biotransistor

    Science.gov (United States)

    Alessandrini, Andrea; Salerno, Marco; Frabboni, Stefano; Facci, Paolo

    2005-03-01

    Metalloproteins are redox molecules naturally shuttling electrons with high efficiency between molecular partners. As such, they are candidates of choice for bioelectronics. In this work, we have used bacterial metalloprotein azurin, hosted in a nanometer gap between two electrically biased gold electrodes, to demonstrate an electrochemically gated single-molecule transistor operating in an aqueous environment. Gold-chemisorbed azurin shows peaks in tunneling current upon changing electrode potential and a related variation in tunneling barrier transparency which can be exploited to switch an electron current through it. These results suggest the wet approach to molecular electronics as a viable method for exploiting electron transfer of highly specialized biomolecules.

  7. Precursor films in wetting phenomena

    OpenAIRE

    Popescu, M. N.; Oshanin, G.; Dietrich, S.; Cazabat, A. -M.

    2012-01-01

    The spontaneous spreading of non-volatile liquid droplets on solid substrates poses a classic problem in the context of wetting phenomena. It is well known that the spreading of a macroscopic droplet is in many cases accompanied by a thin film of macroscopic lateral extent, the so-called precursor film, which emanates from the three-phase contact line region and spreads ahead of the latter with a much higher speed. Such films have been usually associated with liquid-on-solid systems, but in t...

  8. Ultra Low NOx Catalytic Combustion for IGCC Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Shahrokh Etemad; Benjamin Baird; Sandeep Alavandi; William Pfefferle

    2008-03-31

    In order to meet DOE's goals of developing low-emissions coal-based power systems, PCI has further developed and adapted it's Rich-Catalytic Lean-burn (RCL{reg_sign}) catalytic reactor to a combustion system operating on syngas as a fuel. The technology offers ultra-low emissions without the cost of exhaust after-treatment, with high efficiency (avoidance of after-treatment losses and reduced diluent requirements), and with catalytically stabilized combustion which extends the lower Btu limit for syngas operation. Tests were performed in PCI's sub-scale high-pressure (10 atm) test rig, using a two-stage (catalytic then gas-phase) combustion process for syngas fuel. In this process, the first stage consists of a fuel-rich mixture reacting on a catalyst with final and excess combustion air used to cool the catalyst. The second stage is a gas-phase combustor, where the air used for cooling the catalyst mixes with the catalytic reactor effluent to provide for final gas-phase burnout and dilution to fuel-lean combustion products. During testing, operating with a simulated Tampa Electric's Polk Power Station syngas, the NOx emissions program goal of less than 0.03 lbs/MMBtu (6 ppm at 15% O{sub 2}) was met. NOx emissions were generally near 0.01 lbs/MMBtu (2 ppm at 15% O{sub 2}) (PCI's target) over a range on engine firing temperatures. In addition, low emissions were shown for alternative fuels including high hydrogen content refinery fuel gas and low BTU content Blast Furnace Gas (BFG). For the refinery fuel gas increased resistance to combustor flashback was achieved through preferential consumption of hydrogen in the catalytic bed. In the case of BFG, stable combustion for fuels as low as 88 BTU/ft{sup 3} was established and maintained without the need for using co-firing. This was achieved based on the upstream catalytic reaction delivering a hotter (and thus more reactive) product to the flame zone. The PCI catalytic reactor was also shown

  9. Hydrolysis of Miscanthus for bioethanol production using dilute acid presoaking combined with wet explosion pre-treatment and enzymatic treatment

    DEFF Research Database (Denmark)

    Sørensen, Annette; Teller, Philip Johan; Hilstrøm, Troels;

    2008-01-01

    xylose prior to wet explosion. The acid presoaking extracted 63.2% xylose and 5.2% glucose. Direct enzymatic hydrolysis of the presoaked biomass was found to give only low sugar yields of 24-26% glucose. Wet explosion is a pre-treatment method that combines wet-oxidation and steam explosion. The effect...... of wet explosion on non-presoaked and presoaked Miscanthus was investigated using both atmospheric air and hydrogen peroxide as the oxidizing agent. All wet explosion pre-treatments showed to have a disrupting effect on the lignocellulosic biomass, making the sugars accessible for enzymatic hydrolysis......Miscanthus is a high yielding bioenergy crop. In this study we used acid presoaking, wet explosion, and enzymatic hydrolysis to evaluate the combination of the different pre-treatment methods for bioethanol production with Miscanthus. Acid presoaking is primarily carried out in order to remove...

  10. 排气质量流量和过量空气系数对三效催化转换器动态特性的影响%Effect of Exhaust Mass Flow and Inlet Excess Air Ratio on Dynamic Characteristic of Three-Way Catalytic Converter

    Institute of Scientific and Technical Information of China (English)

    何玲; 于秀敏; 李国良; 李想; 杜婷婷; 许艳军

    2011-01-01

    在发动机瞬态工况下,试验研究了排气质量流量、过量空气系数的阶跃幅值和周期对三效催化转换器动态特性的影响规律.试验结果表明,排气质量流量、过量空气系数的阶跃幅值和周期对三效催化转换器活性层中铈(Ce)表面氧气吸附和脱附存储能力(OSC)、排放影响显著.稀混合气向浓混合气阶跃后,排气质量流量增加,出口过量空气系数在理论混合气的时间并不线性增加,三效催化转换器出口排放降低,排气流量增加到一定值时,排放性能恶化.由浓混合气向稀混合气阶跃后,催化转换器出口的过量空气系数在理论混合气的时间随排气质量流量、过量空气系数的幅值线性增加.老化三效催化转换器的氧存储力减弱,是车载自动诊断系统(OBD)检测催化转换器是否老化的依据.%Dynamic response of three-way catalytic converter with different exhaust mass flows, inlet amplitude and period was analyzed experimentally under transient conditions. Results show that engine emissions and oxygen storage capacity (OSC)of three-way catalytic converter with Ceria (Ce)catalyst on the washcoat is affected by exhaust mass flow, amplitude and period of inlet excess air ratio. When ex- haust mass flow increases, emissions decrease at the beginning and turn deteriorated at some mass flow, and duration of outlet excess air ratio at stoichiometry increases non-linearly after the lean-rich step. Dura- tion of outlet excess air ratio at stoichiometry increases linearly as increasing exhaust mass flow and outlet excess air ratio amplitude after the rich-lean step. Oxygen storage capacity of Ceria of aged three-way cata- lytic converter is low and the on-board diagnostics (OBD) can diagnose the condition of three-way cata- lytic converter.

  11. Catalytic production of biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Theilgaard Madsen, A.

    2011-07-01

    The focus of this thesis is the catalytic production of diesel from biomass, especially emphasising catalytic conversion of waste vegetable oils and fats. In chapter 1 an introduction to biofuels and a review on different catalytic methods for diesel production from biomass is given. Two of these methods have been used industrially for a number of years already, namely the transesterification (and esterification) of oils and fats with methanol to form fatty acid methyl esters (FAME), and the hydrodeoxygenation (HDO) of fats and oils to form straight-chain alkanes. Other possible routes to diesel include upgrading and deoxygenation of pyrolysis oils or aqueous sludge wastes, condensations and reductions of sugars in aqueous phase (aqueous-phase reforming, APR) for monofunctional hydrocarbons, and gasification of any type of biomass followed by Fischer-Tropsch-synthesis for alkane biofuels. These methods have not yet been industrialised, but may be more promising due to the larger abundance of their potential feedstocks, especially waste feedstocks. Chapter 2 deals with formation of FAME from waste fats and oils. A range of acidic catalysts were tested in a model fat mixture of methanol, lauric acid and trioctanoin. Sulphonic acid-functionalised ionic liquids showed extremely fast convertion of lauric acid to methyl laurate, and trioctanoate was converted to methyl octanoate within 24 h. A catalyst based on a sulphonated carbon-matrix made by pyrolysing (or carbonising) carbohydrates, so-called sulphonated pyrolysed sucrose (SPS), was optimised further. No systematic dependency on pyrolysis and sulphonation conditions could be obtained, however, with respect to esterification activity, but high activity was obtained in the model fat mixture. SPS impregnated on opel-cell Al{sub 2}O{sub 3} and microporous SiO{sub 2} (ISPS) was much less active in the esterification than the original SPS powder due to low loading and thereby low number of strongly acidic sites on the

  12. Reactive wetting properties of TiO2 nanoparticles predicted by ab initio molecular dynamics simulations

    Science.gov (United States)

    Brandt, Erik G.; Agosta, Lorenzo; Lyubartsev, Alexander P.

    2016-07-01

    Small-sized wet TiO2 nanoparticles have been investigated by ab initio molecular dynamics simulations. Chemical and physical adsorption of water on the TiO2-water interface was studied as a function of water content, ranging from dry nanoparticles to wet nanoparticles with monolayer coverage of water. The surface reactivity was shown to be a concave function of water content and driven by surface defects. The local coordination number at the defect was identified as the key factor to decide whether water adsorption proceeds through dissociation or physisorption on the surface. A consistent picture of TiO2 nanoparticle wetting at the microscopic level emerges, which corroborates existing experimental data and gives further insight into the molecular mechanisms behind nanoparticle wetting. These calculations will facilitate the engineering of metal oxide nanoparticles with a controlled catalytic water activity.Small-sized wet TiO2 nanoparticles have been investigated by ab initio molecular dynamics simulations. Chemical and physical adsorption of water on the TiO2-water interface was studied as a function of water content, ranging from dry nanoparticles to wet nanoparticles with monolayer coverage of water. The surface reactivity was shown to be a concave function of water content and driven by surface defects. The local coordination number at the defect was identified as the key factor to decide whether water adsorption proceeds through dissociation or physisorption on the surface. A consistent picture of TiO2 nanoparticle wetting at the microscopic level emerges, which corroborates existing experimental data and gives further insight into the molecular mechanisms behind nanoparticle wetting. These calculations will facilitate the engineering of metal oxide nanoparticles with a controlled catalytic water activity. Electronic supplementary information (ESI) available: Simulation data on equilibration of energies and structures (root-mean-square-deviations and

  13. Elucidating the mysteries of wetting.

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Edmund Blackburn, III (,; ); Bourdon, Christopher Jay; Grillet, Anne Mary; Sackinger, Philip A.; Grest, Gary Stephen; Emerson, John Allen; Ash, Benjamin Jesse; Heine, David R.; Brooks, Carlton, F.; Gorby, Allen D.

    2005-11-01

    Nearly every manufacturing and many technologies central to Sandia's business involve physical processes controlled by interfacial wetting. Interfacial forces, e.g. conjoining/disjoining pressure, electrostatics, and capillary condensation, are ubiquitous and can surpass and even dominate bulk inertial or viscous effects on a continuum level. Moreover, the statics and dynamics of three-phase contact lines exhibit a wide range of complex behavior, such as contact angle hysteresis due to surface roughness, surface reaction, or compositional heterogeneities. These thermodynamically and kinetically driven interactions are essential to the development of new materials and processes. A detailed understanding was developed for the factors controlling wettability in multicomponent systems from computational modeling tools, and experimental diagnostics for systems, and processes dominated by interfacial effects. Wettability probed by dynamic advancing and receding contact angle measurements, ellipsometry, and direct determination of the capillary and disjoining forces. Molecular scale experiments determined the relationships between the fundamental interactions between molecular species and with the substrate. Atomistic simulations studied the equilibrium concentration profiles near the solid and vapor interfaces and tested the basic assumptions used in the continuum approaches. These simulations provide guidance in developing constitutive equations, which more accurately take into account the effects of surface induced phase separation and concentration gradients near the three-phase contact line. The development of these accurate models for dynamic multicomponent wetting allows improvement in science based engineering of manufacturing processes previously developed through costly trial and error by varying material formulation and geometry modification.

  14. Catalytic combustion over high temperature stable metal oxides

    Energy Technology Data Exchange (ETDEWEB)

    Berg, M. [TPS Termiska Processer AB, Nykoeping (Sweden)

    1996-12-31

    This thesis presents a study of the catalytic effects of two interesting high temperature stable metal oxides - magnesium oxide and manganese substituted barium hexa-aluminate (BMA) - both of which can be used in the development of new monolithic catalysts for such applications. In the first part of the thesis, the development of catalytic combustion for gas turbine applications is reviewed, with special attention to alternative fuels such as low-BTU gas, e.g. produced in an air blown gasifier. When catalytic combustion is applied for such a fuel, the primary advantage is the possibility of decreasing the conversion of fuel nitrogen to NO{sub x}, and achieving flame stability. In the experimental work, MgO was shown to have a significant activity for the catalytic combustion of methane, lowering the temperature needed to achieve 10 percent conversion by 270 deg C compared with homogeneous combustion.The reaction kinetics for methane combustion over MgO was also studied. It was shown that the heterogeneous catalytic reactions were dominant but that the catalytically initiated homogeneous gas phase reactions were also important, specially at high temperatures. MgO and BMA were compared. The latter showed a higher catalytic activity, even when the differences in activity decreased with increasing calcination temperature. For BMA, CO{sub 2} was the only product detected, but for MgO significant amounts of CO and C{sub 2}-hydrocarbons were formed. BMA needed a much lower temperature to achieve total conversion of other fuels, e.g. CO and hydrogen, compared to the temperature for total conversion of methane. This shows that BMA-like catalysts are interesting for combustion of fuel mixtures with high CO and H{sub 2} content, e.g. gas produced from gasification of biomass. 74 refs

  15. Catalytic cracking of lignites

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, M.; Nowak, S.; Naegler, T.; Zimmermann, J. [Hochschule Merseburg (Germany); Welscher, J.; Schwieger, W. [Erlangen-Nuernberg Univ. (Germany); Hahn, T. [Halle-Wittenberg Univ., Halle (Germany)

    2013-11-01

    A most important factor for the chemical industry is the availability of cheap raw materials. As the oil price of crude oil is rising alternative feedstocks like coal are coming into focus. This work, the catalytic cracking of lignite is part of the alliance ibi (innovative Braunkohlenintegration) to use lignite as a raw material to produce chemicals. With this new one step process without an input of external hydrogen, mostly propylene, butenes and aromatics and char are formed. The product yield depends on manifold process parameters. The use of acid catalysts (zeolites like MFI) shows the highest amount of the desired products. Hydrogen rich lignites with a molar H/C ratio of > 1 are to be favoured. Due to primary cracking and secondary reactions the ratio between catalyst and lignite, temperature and residence time are the most important parameter to control the product distribution. Experiments at 500 C in a discontinuous rotary kiln reactor show yields up to 32 wt-% of hydrocarbons per lignite (maf - moisture and ash free) and 43 wt-% char, which can be gasified. Particularly, the yields of propylene and butenes as main products can be enhanced four times to about 8 wt-% by the use of catalysts while the tar yield decreases. In order to develop this innovative process catalyst systems fixed on beads were developed for an easy separation and regeneration of the used catalyst from the formed char. (orig.)

  16. Catalytic Membrane Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, T.J.; Brinker, C.J.; Gardner, T.J.; Hughes, R.C.; Sault, A.G.

    1998-12-01

    The proposed "catalytic membrane sensor" (CMS) was developed to generate a device which would selectively identify a specific reagent in a complex mixture of gases. This was to be accomplished by modifying an existing Hz sensor with a series of thin films. Through selectively sieving the desired component from a complex mixture and identifying it by decomposing it into Hz (and other by-products), a Hz sensor could then be used to detect the presence of the select component. The proposed "sandwich-type" modifications involved the deposition of a catalyst layered between two size selective sol-gel layers on a Pd/Ni resistive Hz sensor. The role of the catalyst was to convert organic materials to Hz and organic by-products. The role of the membraneo was to impart both chemical specificity by molecukir sieving of the analyte and converted product streams, as well as controlling access to the underlying Pd/Ni sensor. Ultimately, an array of these CMS elements encompassing different catalysts and membranes were to be developed which would enable improved selectivity and specificity from a compiex mixture of organic gases via pattern recognition methodologies. We have successfully generated a CMS device by a series of spin-coat deposited methods; however, it was determined that the high temperature required to activate the catalyst, destroys the sensor.

  17. Catalytic gasification of biomass

    Science.gov (United States)

    Robertus, R. J.; Mudge, L. K.; Sealock, L. J., Jr.; Mitchell, D. H.; Weber, S. L.

    1981-12-01

    Methane and methanol synthesis gas can be produced by steam gasification of biomass in the presence of appropriate catalysts. This concept is to use catalysts in a fluidized bed reactor which is heated indirectly. The objective is to determine the technical and economic feasibility of the concept. Technically the concept has been demonstrated on a 50 lb per hr scale. Potential advantages over conventional processes include: no oxygen plant is needed, little tar is produced so gas and water treatment are simplified, and yields and efficiencies are greater than obtained by conventional gasification. Economic studies for a plant processing 2000 T/per day dry wood show that the cost of methanol from wood by catalytic gasification is competitive with the current price of methanol. Similar studies show the cost of methane from wood is competitive with projected future costs of synthetic natural gas. When the plant capacity is decreased to 200 T per day dry wood, neither product is very attractive in today's market.

  18. Catalytic Hydrothermal Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Douglas C.

    2015-05-31

    The term “hydrothermal” used here refers to the processing of biomass in water slurries at elevated temperature and pressure to facilitate the chemical conversion of the organic structures in biomass into useful fuels. The process is meant to provide a means for treating wet biomass materials without drying and to access ionic reaction conditions by maintaining a liquid water processing medium. Typical hydrothermal processing conditions are 523-647K of temperature and operating pressures from 4-22 MPa of pressure. The temperature is sufficient to initiate pyrolytic mechanisms in the biopolymers while the pressure is sufficient to maintain a liquid water processing phase. Hydrothermal gasification is accomplished at the upper end of the process temperature range. It can be considered an extension of the hydrothermal liquefaction mechanisms that begin at the lowest hydrothermal conditions with subsequent decomposition of biopolymer fragments formed in liquefaction to smaller molecules and eventually to gas. Typically, hydrothermal gasification requires an active catalyst to accomplish reasonable rates of gas formation from biomass.

  19. Immigration process in catalytic medium

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The longtime behavior of the immigration process associated with a catalytic super-Brownian motion is studied. A large number law is proved in dimension d≤3 and a central limit theorem is proved for dimension d=3.

  20. Immigration process in catalytic medium

    Institute of Scientific and Technical Information of China (English)

    洪文明; 王梓坤

    2000-01-01

    The longtime behavior of the immigration process associated with a catalytic super-Brown-ian motion is studied. A large number law is proved in dimension d≤3 and a central limit theorem is proved for dimension d = 3.

  1. Wetting and Non-Wetting Models of Black Carbon Activation

    Science.gov (United States)

    Henson, B. F.; Laura, S.

    2006-12-01

    We present the results of recent modeling studies on the activation of black carbon (BC) aerosol to form cloud condensation nuclei (CCN). We use a model of BC activation based on a general modification of the Koehler equation for insoluble activation in which we introduce a term based on the activity of water adsorbed on the particle surface. We parameterize the model using the free energy of adsorption, a parameter directly comparable to laboratory measurements of water adsorption on carbon. Although the model of the water- surface interaction is general, the form of the activation equation that results depends upon a further model of the distribution of water on the particle. One possible model involves the symmetric growth of a water shell around the isoluble particle core (wetting). This model predicts upper and lower bounding curves for the activation supersaturation given by the range of water interaction energies from hydrophobic to hydrophilic which are in agreement with a large body of recent activation data. The resulting activation diameters are from 3 to 10 times smaller than activation of soluble particles of identical dry diameter. Another possible model involves an exluded liquid droplet growing in contact with the particle (non-wetting). The geometry of this model much more resembles classic assumptions of heterogeneous nucleation theory. This model can yield extremely high activation supersaturation as a function of diameter, as has been observed in some experiments, and enables calculations in agreement with some of these results. We discuss these two geometrical models of water growth, the different behaviors predicted by the resulting activation equation, and the means to determine which model of growth is appropriate for a given BC particle characterized by either water interaction energy or morphology. These simple models enable an efficient and physically reasonable means to calculate the activation of BC aerosol to form CCN based upon a

  2. Mechanisms of wet oxidation by hydrogen peroxide

    International Nuclear Information System (INIS)

    A research programme is currently under way at BNL and MEL to investigate the possible use of Hydrogen Peroxide with metal ion catalysts as a wet oxidation treatment system for CEGB organic radioactive wastes. The published literature relating to the kinetics and mechanism of oxidation and decomposition reactions of hydrogen peroxide is reviewed and the links with practical waste management by wet oxidation are examined. Alternative wet oxidation systems are described and the similarities to the CEGB research effort are noted. (author)

  3. Catalytic glycerol steam reforming for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Monica, E-mail: monica.dan@itim-cj.ro; Mihet, Maria, E-mail: maria.mihet@itim-cj.ro; Lazar, Mihaela D., E-mail: diana.lazar@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj Napoca (Romania)

    2015-12-23

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H{sub 2}. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al{sub 2}O{sub 3}. The catalyst was prepared by wet impregnation method and characterized through different methods: N{sub 2} adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H{sub 2}, CH{sub 4}, CO, CO{sub 2}. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H{sub 2}O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  4. Catalytic glycerol steam reforming for hydrogen production

    Science.gov (United States)

    Dan, Monica; Mihet, Maria; Lazar, Mihaela D.

    2015-12-01

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H2. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al2O3. The catalyst was prepared by wet impregnation method and characterized through different methods: N2 adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H2, CH4, CO, CO2. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H2O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  5. Determination of fungal spore release from wet building materials

    DEFF Research Database (Denmark)

    Kildesø, J.; Wurtz, H.; Nielsen, Kristian Fog;

    2003-01-01

    of typical indoor fungi has been measured under controlled conditions. The fungi were cultivated for a period of 4-6 weeks on sterilized wet wallpapered gypsum boards at a relative humidity (RH) of approximately 97%. A specially designed small chamber (P-FLEC) was placed on the gypsum board. The release...... and Trichoderma harzianum ), the number of spores produced on the gypsum board and subsequently released was quantified. Also the relationship between air velocities from 0.3 to 3 m/s over the surface and spore release has been measured. The method was found to give very reproducible results for each fungal...

  6. Modified Wenzel and Cassie equations for wetting on rough surfaces

    CERN Document Server

    Xu, Xianmin

    2016-01-01

    We study a stationary wetting problem on rough and inhomogeneous solid surfaces. We derive a new formula for the apparent contact angle by asymptotic two-scale homogenization method. The formula reduces to a modified Wenzel equation for geometrically rough surfaces and a modified Cassie equation for chemically inhomogeneous surfaces. Unlike the classical Wenzel and Cassie equations, the modified equations correspond to local minimizers of the total interface energy in the solid-liquid-air system, so that they are consistent with experimental observations. The homogenization results are proved rigorously by a variational method.

  7. Carbon nanotube fiber spun from wetted ribbon

    Science.gov (United States)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  8. A mesoscopic model for (de)wetting.

    Science.gov (United States)

    Merabia, S; Pagonabarraga, I

    2006-06-01

    We present a mesoscopic model for simulating the dynamics of a non-volatile liquid on a solid substrate. The wetting properties of the solid can be tuned from complete wetting to total non-wetting. This model opens the way to study the dynamics of drops and liquid thin films at mesoscopic length scales of the order of the nanometer. As particular applications, we analyze the kinetics of spreading of a liquid drop wetting a solid substrate and the dewetting of a liquid film on a hydrophobic substrate. In all these cases, very good agreement is found between simulations and theoretical predictions. PMID:16775662

  9. Thunderstorms Increase Mercury Wet Deposition.

    Science.gov (United States)

    Holmes, Christopher D; Krishnamurthy, Nishanth P; Caffrey, Jane M; Landing, William M; Edgerton, Eric S; Knapp, Kenneth R; Nair, Udaysankar S

    2016-09-01

    Mercury (Hg) wet deposition, transfer from the atmosphere to Earth's surface by precipitation, in the United States is highest in locations and seasons with frequent deep convective thunderstorms, but it has never been demonstrated whether the connection is causal or simple coincidence. We use rainwater samples from over 800 individual precipitation events to show that thunderstorms increase Hg concentrations by 50% relative to weak convective or stratiform events of equal precipitation depth. Radar and satellite observations reveal that strong convection reaching the upper troposphere (where high atmospheric concentrations of soluble, oxidized mercury species (Hg(II)) are known to reside) produces the highest Hg concentrations in rain. As a result, precipitation meteorology, especially thunderstorm frequency and total rainfall, explains differences in Hg deposition between study sites located in the eastern United States. Assessing the fate of atmospheric mercury thus requires bridging the scales of global transport and convective precipitation. PMID:27464305

  10. Catalytic Synthesis of Nitriles in Continuous Flow

    DEFF Research Database (Denmark)

    Nordvang, Emily Catherine

    The objective of this thesis is to report the development of a new, alternative process for the flexible production of nitrile compounds in continuous flow. Nitriles are an important class of compounds that find applications as solvents, chemical intermediates and pharmaceutical compounds......, alternative path to acetonitrile from ethanol via the oxidative dehydrogenation of ethylamine. The catalytic activity and product ratios of the batch and continuous flow reactions are compared and the effect of reaction conditions on the reaction is investigated. The effects of ammonia in the reaction...... dehydrogenation of ethylamine and post-reaction purging.Chapter 4 outlines the application of RuO2/Al2O3 catalysts to the oxidative dehydrogenation of benzylamine in air, utilizing a new reaction setup. Again, batch and continuous flow reactions are compared and the effects of reaction conditions, ammonia...

  11. Effects of Gas Velocity and Temperature on Nitric Oxide Conversion in Simulated Catalytic Converter

    OpenAIRE

    Sathaporn Chuepeng

    2012-01-01

    Problem statement: Gaseous emissions from gasoline engine such as carbon monoxide, unburned hydrocarbon and nitrogen oxides were usually reduced in three-way catalytic converter simultaneously around theoretical fuel and air combustion. Engine speed and load and other parameters were varied over a wide range of operating conditions, resulting in different exhaust gas composition and condition intake into catalytic converter. This work was studied the conversion of Nitric Oxide (NO) in exhaust...

  12. Characterization of Catalytic Porous Medium Using Platinum for Micro-combustion Application

    OpenAIRE

    Miskam Muhamad Azman; Hassan Suhaimi; Zainal Alauddin Zainal Alimuddin; Ishak Mohammad Zulfikar

    2014-01-01

    In this study, catalytic alumina porous medium has been fabricated by using platinum as an active material for micro-combustion application. Platinum has been deposited onto porous medium surface via wet impregnation method. The porous medium undergoes surface modification process via wash coating method using gamma alumina (γ-Al2O3) solution, before being impregnated with platinum in order to increase the surface area. The surface morphology of porous medium entirely changes from smooth “sol...

  13. Time-varying wetting behavior on copper wafer treated by wet-etching

    Energy Technology Data Exchange (ETDEWEB)

    Tu, Sheng-Hung; Wu, Chuan-Chang [Department of Chemical and Materials Engineering, National Central University, Jhongli 320, Taiwan, ROC (China); Wu, Hsing-Chen [Advanced Technology Materials Inc, Hsinchu 310, Taiwan, ROC (China); Cheng, Shao-Liang [Department of Chemical and Materials Engineering, National Central University, Jhongli 320, Taiwan, ROC (China); Sheng, Yu-Jane, E-mail: yjsheng@ntu.edu.tw [Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Tsao, Heng-Kwong, E-mail: hktsao@cc.ncu.edu.tw [Department of Chemical and Materials Engineering, National Central University, Jhongli 320, Taiwan, ROC (China)

    2015-06-30

    Graphical abstract: - Highlights: • A thin oxide layer always remains on surfaces of Cu wafers after aqueous etching. • A pure Cu wafer is obtained by the HAc treatment and the water CA is about 45°. • The oxide layer and CA grow with time after the Cu wafer is exposed to air. • Surface roughness and hydrophobicity of pure Cu wafers grow rapidly in vacuum. - Abstract: The wet cleaning process in semiconductor fabrication often involves the immersion of the copper wafer into etching solutions and thereby its surface properties are significantly altered. The wetting behavior of a copper film deposited on silicon wafer is investigated after a short dip in various etching solutions. The etchants include glacial acetic acid and dilute solutions of nitric acid, hydrofluoric acid, and tetramethylammonium hydroxide. It was found that in most cases a thin oxide layer still remains on the surface of as-received Cu wafers when they are subject to etching treatments. However, a pure Cu wafer can be obtained by the glacial acetic acid treatment and its water contact angle (CA) is about 45°. As the pure Cu wafer is placed in the ambient condition, the oxide thickness grows rapidly to the range of 10–20 Å within 3 h and the CA on the hydrophilic surface also rises. In the vacuum, it is surprising to find that the CA and surface roughness of the pure Cu wafer can grow significantly. These interesting results may be attributed to the rearrangement of surface Cu atoms to reduce the surface free energy.

  14. Fast and Slow Wetting Dynamics on nanostructured surfaces

    Science.gov (United States)

    Nandyala, Dhiraj; Rahmani, Amir; Cubaud, Thomas; Colosqui, Carlos

    2015-11-01

    This talk will present force-displacement and spontaneous drop spreading measurements on diverse nanostructured surfaces (e.g., mesoporous titania thin films, nanoscale pillared structures, on silica or glass substrates). Experimental measurements are performed for water-air and water-oil systems. The dynamics of wetting observed in these experiments can present remarkable crossovers from fast to slow or arrested dynamics. The emergence of a slow wetting regime is attributed to a multiplicity of metastable equilibrium states induced by nanoscale surface features. The crossover point can be dramatically advanced or delayed by adjusting specific physical parameters (e.g., viscosity of the wetting phases) and geometric properties of the surface nanostructure (e.g., nanopore/pillar radius and separation). Controlling the crossover point to arrested dynamics can effectively modify the degree of contact angle hysteresis and magnitude of liquid adhesion forces observed on surfaces of different materials. This work is supported by a SEED Award from The Office of Brookhaven National Laboratory Affairs at Stony Brook University.

  15. 湿式氧化-磷酸盐固定化组合工艺处理磷霉素制药废水及其资源化%Fosfomycin pharmaceutical wastewater treatment and phosphorus recovery using hybrid wet air oxidation-phosphate immobilization process

    Institute of Scientific and Technical Information of China (English)

    邱光磊; 宋永会; 曾萍; 肖书虎; 段亮; 彭剑峰; 袁鹏

    2011-01-01

    采用湿式氧化-磷酸盐固定化组合工艺处理COD为72750mg·L-1、总有机磷(TOP)为8225 mg·L-1的磷霉素制药废水并对废水中磷进行资源化回收.首先,采用湿式氧化工艺,利用分子氧作为氧化剂,将废水中有机磷转化成无机磷酸盐,分别考察了反应温度、氧分压和废水初始pH值对湿式氧化处理效果的影响,结果显示:在反应温度200℃、氧分压为1.0 MPa、废水初始pH值为11.2的条件下,湿式氧化工艺可实现废水中COD去除率57%、TOP去除率99%以上,高反应温度、高氧分压以及高废水初始pH值对COD和TOP的去除有利.采用磷酸钙(CP)沉淀和磷酸铵镁(MgNH4PO46H2O,MAP)结晶方法,对湿式氧化处理后废水中磷酸盐进行固定化回收,考察了不同Ca2+/PO34-摩尔比以及Mg2+/NH4+/PO34-摩尔比条件下,磷酸盐固定化工艺对湿式氧化处理后磷霉素废水中磷的回收效果,结果显示:在Ca2+/PO34-摩尔比2∶1以及Mg2+/NH4+/PO34-摩尔比1.1∶1∶1,废水PO34--P浓度9500mg·L-1条件下,CP沉淀和MAP结晶工艺均可以实现磷酸盐固定化回收率99.9%以上,出水PO34--P浓度低于5.0 mg·L-1.采用扫描电子显微镜(SEM)和X射线衍射(XRD)对固定化磷回收产物进行了表征,结果表明回收产物分别为具有较高纯净度的MAP和掺杂有一定量无定形磷酸钙的羟基磷灰石(Ca5(PO4)3OH,HAP).%Hybrid wet air oxidation-phosphate immobilization was applied to fosfomycin wastewater treatment and phosphorus recovery. The chemical oxygen demand (COD) and total organic phosphorus (TOP) concentrations of the wastewater were 72750 mg·L-1 and 8225 mg·L-1 , respectively. Firstly, O2 was used as oxidant in the wet air oxidation process to break down and transform concentrated and refractory organic phosphorus substances into phosphate, and the effects of reaction temperature, oxygen partial pressure and initial wastewater pH value were studied. The

  16. Laboratory Evaluation of Electrostatic Spray Wet Scrubber to Control Particulate Matter Emissions from Poultry Facilities

    Science.gov (United States)

    Particulate matter (PM) is a major air pollutant emitted from animal production and has significant impacts on health and the environment. Abatement of PM emissions is imperative and effective PM control technologies are strongly needed. In this work, an electrostatic spray wet scrubber (ESWS) techn...

  17. Generalization of the Wet-Bulb Temperature Notion to the Case of Electromagnetic Drying

    Science.gov (United States)

    Afanas'ev, A. M.; Siplivyi, B. N.

    2016-05-01

    A method of estimating the stationary temperature of the surface a body blown over by air and subjected to the action of electromagnetic radiation, representing a generalization of the wet-bulb temperature notion to the case of electromagnetic drying, has been developed.

  18. Characteristics of wet work in nurses

    NARCIS (Netherlands)

    Jungbauer, FHW; Steenstra, FB; Groothoff, JW; Coenraads, PJ

    2005-01-01

    Background objectives: Nursing is known for its high prevalence of hand dermatitis, mainly caused by the intense exposure to wet work in nursing activities. We aimed to study the characteristics of wet work exposure in nursing. Method: Trained observers monitored the duration and frequency of differ

  19. Curvature controlled wetting in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Mikheev, Lev V.

    1995-01-01

    A complete wetting transition at vanishing curvature of the substrate in two-dimensional circular geometry is studied by the transfer matrix method. We find an exact formal mapping of the partition function of the problem onto that of a (1+1)-dimensional wetting problem in planar geometry...

  20. 7 CFR 29.2316 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.2316 Section 29.2316 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Official Standard Grades for Virginia Fire-Cured Tobacco (u.s. Type 21) § 29.2316 Wet...

  1. 7 CFR 29.3077 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.3077 Section 29.3077 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in an unsafe...

  2. 7 CFR 29.2570 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.2570 Section 29.2570 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2570 Wet (W). Any sound tobacco...

  3. 7 CFR 29.1083 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.1083 Section 29.1083 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1083 Wet (W). Any sound tobacco containing excessive moisture to the extent that it is...

  4. 7 CFR 29.3567 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.3567 Section 29.3567 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3567 Wet (W). Any sound tobacco containing excessive moisture to the extent that it is...

  5. Anomalous wetting of helium on cesium

    International Nuclear Information System (INIS)

    The authors report studies of the anomalous wetting of a cesium substrate by a liquid helium film by means of the technique of third sound. A hysteretic pre-wetting transition is observed as a function of the amount of helium in the experimental cell. 10 refs., 2 figs

  6. 40 CFR 63.5870 - How do I calculate annual uncontrolled and controlled organic HAP emissions from my wet-out area...

    Science.gov (United States)

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic... and controlled organic HAP emissions from my wet-out area(s) and from my oven(s) for...

  7. Roles of catalytic oxidation in control of vehicle exhaust emissions

    International Nuclear Information System (INIS)

    Catalytic oxidation was initially associated with the early development of catalysis and it subsequently became a part of many industrial processes, so it is not surprising it was used to remove hydrocarbons and CO when it became necessary to control these emissions from cars. Later NOx was reduced in a process involving reduction over a Pt/Rh catalyst followed by air injection in front of a Pt-based oxidation catalyst. If over-reduction of NO to NH3 took place, or if H2S was produced, it was important these undesirable species were converted to NOx and SOx in the catalytic oxidation stage. When exhaust gas composition could be kept stoichiometric hydrocarbons, CO and NOx were simultaneously converted over a single Pt/Rh three-way catalyst (TWC). With modern TWCs car tailpipe emissions can be exceptionally low. NO is not catalytically dissociated to O2 and N2 in the presence of O2, it can only be reduced to N2. Its control from lean-burn gasoline engines involves catalytic oxidation to NO2 and thence nitrate that is stored and periodically reduced to N2 by exhaust gas enrichment. This method is being modified for diesel engines. These engines produce soot, and filtration is being introduced to remove it. The exhaust temperature of heavy-duty diesels is sufficient (250-400oC) for NO to be catalytically oxidised to NO2 over an upstream platinum catalyst that smoothly oxidises soot in the filter. The exhaust gas temperature of passenger car diesels is too low for this to take place all of the time, so trapped soot is periodically burnt in O2 above 550oC. Catalytic oxidation of higher than normal amounts of hydrocarbon and CO over an upstream catalyst is used to give sufficient temperature for soot combustion with O2 to take place. (author)

  8. Catalytic Hydrothermal Conversion of Wet Biomass Feedstocks and Upgrading – Process Design and Optimization

    DEFF Research Database (Denmark)

    Hoffmann, Jessica; Toor, Saqib; Rosendahl, Lasse

    Liquid biofuels will play a major role for a more sustainable energy system of the future. The CatLiq® process is a 2nd generation biomass conversion process that is based on hydrothermal liquefaction. Hydrothermal liquefaction offers a very efficient and feedstock flexible way of converting...

  9. Long term wet spent nuclear fuel storage

    International Nuclear Information System (INIS)

    The meeting showed that there is continuing confidence in the use of wet storage for spent nuclear fuel and that long-term wet storage of fuel clad in zirconium alloys can be readily achieved. The importance of maintaining good water chemistry has been identified. The long-term wet storage behaviour of sensitized stainless steel clad fuel involves, as yet, some uncertainties. However, great reliance will be placed on long-term wet storage of spent fuel into the future. The following topics were treated to some extent: Oxidation of the external surface of fuel clad, rod consolidation, radiation protection, optimum methods of treating spent fuel storage water, physical radiation effects, and the behaviour of spent fuel assemblies of long-term wet storage conditions. A number of papers on national experience are included

  10. Air Pollution

    Science.gov (United States)

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, ...

  11. Pt-TiO2/MWCNTs Hybrid Composites for Monitoring Low Hydrogen Concentrations in Air

    Directory of Open Access Journals (Sweden)

    Stefano Trocino

    2012-09-01

    Full Text Available Hydrogen is a valuable fuel for the next energy scenario. Unfortunately, hydrogen is highly flammable at concentrations higher than 4% in air. This aspect makes the monitoring of H2 leaks an essential issue for safety reasons, especially in the transportation field. In this paper, nanocomposites based on Pt-doped TiO2/multiwalled carbon nanotubes (MWCNTs have been introduced as sensitive materials for H2 at low temperatures. Pt-TiO2/MWNTs nanocomposites with different composition have been prepared by a simple wet chemical procedure and their morphological, microstructural and electrical properties were investigated. Resistive thick-film devices have been fabricated printing the hybrid nanocomposites on alumina substrates provided with Pt interdigitated electrodes. Electrical tests in air have shown that embedding MWCNTs in the TiO2 matrix modify markedly the electrical conductivity, providing a means to decrease the resistance of the sensing layer. Pt acts as a catalytic additive. Pt-TiO2/MWNTs-based sensors were found to be sensitive to hydrogen at concentrations between 0.5 and 3% in air, satisfying the requisites for practical applications in hydrogen leak detection devices.

  12. Catalytic distillation water recovery subsystem

    Science.gov (United States)

    Budininkas, P.; Rasouli, F.

    1985-01-01

    An integrated engineering breadboard subsystem for the recovery of potable water from untreated urine based on the vapor phase catalytic ammonia removal was designed, fabricated and tested. Unlike other evaporative methods, this process catalytically oxidizes ammonia and volatile hydrocarbons vaporizing with water to innocuous products; therefore, no pretreatment of urine is required. Since the subsystem is fabricated from commercially available components, its volume, weight and power requirements are not optimized; however, it is suitable for zero-g operation. The testing program consists of parametric tests, one month of daily tests and a continuous test of 168 hours duration. The recovered water is clear, odorless, low in ammonia and organic carbon, and requires only an adjustment of its pH to meet potable water standards. The obtained data indicate that the vapor phase catalytic ammonia removal process, if further developed, would also be competitive with other water recovery systems in weight, volume and power requirements.

  13. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    Vivek V Ranade

    2014-03-01

    Catalytic reactions are ubiquitous in chemical and allied industries. A homogeneous or heterogeneous catalyst which provides an alternative route of reaction with lower activation energy and better control on selectivity can make substantial impact on process viability and economics. Extensive studies have been conducted to establish sound basis for design and engineering of reactors for practising such catalytic reactions and for realizing improvements in reactor performance. In this article, application of recent (and not so recent) developments in engineering reactors for catalytic reactions is discussed. Some examples where performance enhancement was realized by catalyst design, appropriate choice of reactor, better injection and dispersion strategies and recent advances in process intensification/ multifunctional reactors are discussed to illustrate the approach.

  14. Catalytic activity of Au nanoparticles

    DEFF Research Database (Denmark)

    Larsen, Britt Hvolbæk; Janssens, Ton V.W.; Clausen, Bjerne;

    2007-01-01

    Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change with par......Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change...... with particle size. We find that the fraction of low-coordinated Au atoms scales approximately with the catalytic activity, suggesting that atoms on the corners and edges of Au nanoparticles are the active sites. This effect is explained using density functional calculations....

  15. Precursor films in wetting phenomena

    International Nuclear Information System (INIS)

    The spontaneous spreading of non-volatile liquid droplets on solid substrates poses a classic problem in the context of wetting phenomena. It is well known that the spreading of a macroscopic droplet is in many cases accompanied by a thin film of macroscopic lateral extent, the so-called precursor film, which emanates from the three-phase contact line region and spreads ahead of the latter with a much higher speed. Such films have been usually associated with liquid-on-solid systems, but in the last decade similar films have been reported to occur in solid-on-solid systems. While the situations in which the thickness of such films is of mesoscopic size are fairly well understood, an intriguing and yet to be fully understood aspect is the spreading of microscopic, i.e. molecularly thin, films. Here we review the available experimental observations of such films in various liquid-on-solid and solid-on-solid systems, as well as the corresponding theoretical models and studies aimed at understanding their formation and spreading dynamics. Recent developments and perspectives for future research are discussed. (topical review)

  16. Precursor films in wetting phenomena.

    Science.gov (United States)

    Popescu, M N; Oshanin, G; Dietrich, S; Cazabat, A-M

    2012-06-20

    The spontaneous spreading of non-volatile liquid droplets on solid substrates poses a classic problem in the context of wetting phenomena. It is well known that the spreading of a macroscopic droplet is in many cases accompanied by a thin film of macroscopic lateral extent, the so-called precursor film, which emanates from the three-phase contact line region and spreads ahead of the latter with a much higher speed. Such films have been usually associated with liquid-on-solid systems, but in the last decade similar films have been reported to occur in solid-on-solid systems. While the situations in which the thickness of such films is of mesoscopic size are fairly well understood, an intriguing and yet to be fully understood aspect is the spreading of microscopic, i.e. molecularly thin, films. Here we review the available experimental observations of such films in various liquid-on-solid and solid-on-solid systems, as well as the corresponding theoretical models and studies aimed at understanding their formation and spreading dynamics. Recent developments and perspectives for future research are discussed. PMID:22627067

  17. Wetting in mixtures of water, nonionic amphiphiles, and nonpolar solvents

    Science.gov (United States)

    Kahlweit, M.; Busse, G.

    1989-07-01

    As is well known, medium- and long-chain alkanes do not spread across H2O-air interfaces, but shape a lens. In this paper it is shown that the same holds for the upper amphiphile-rich phase in binary H2O-amphiphile mixtures with medium- and long-chain nonionic amphiphiles that show a (closed) miscibility gap with water. This finding is somewhat unexpected because surfactants form monolayers at H2O-air interfaces which should facilitate the spreading of the amphiphile-rich phase. This wetting behavior corresponds to that in ternary H2O-oil-nonionic amphiphile mixtures with a three-phase body, in which the middle amphiphile-rich phase does not spread across the H2O-oil interface. The results may stimulate further studies on critical-point wetting [for a recent review see, e.g., S. Dietrich, in Phase Transitions and Critical Phenomena, edited by C. Domb and J. L. Lebowitz (Academic, London, 1988), Vol. 12, p. 1.], and may also help clarifying the properties of microemulsions [for a recent review see, e.g., M. Kahlweit, R. Strey, P. Firman, D. Haase, J. Jen, and R. Schomäcker, Langmuir 4, 499 (1988)].

  18. Development of Pillared Clays for Wet Hydrogen Peroxide Oxidation of Phenol and Its Application in the Posttreatment of Coffee Wastewater

    OpenAIRE

    Nancy R. Sanabria; Rafael Molina; Sonia Moreno

    2012-01-01

    This paper focuses on the use of pillared clays as catalysts for the Fenton-like advanced oxidation, specifically wet hydrogen peroxide catalytic oxidation (WHPCO). This paper discusses the limitations on the application of a homogeneous Fenton system, development of solid catalysts for the oxidation of phenol, advances in the synthesis of pillared clays, and their potential application as catalysts for phenol oxidation. Finally, it analyzes the use of pillared clays as heterogeneous Fenton-l...

  19. Catalytic destruction of tar in biomass derived producer gas

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate catalytic destruction of tar formed during gasification of biomass, with the goal of improving the quality of the producer gas. This work focuses on nickel based catalysts treated with alkali in an effort to promote steam gasification of the coke that deposits on catalyst surfaces. A tar conversion system consisting of a guard bed and catalytic reactor was designed to treat the producer gas from an air blown, fluidized bed biomass gasifier. The guard bed used dolomite to crack the heavy tars. The catalytic reactor was used to evaluate three commercial steam reforming catalysts. These were the ICI46-1 catalyst from Imperial Chemical Industry and Z409 and RZ409 catalysts from Qilu Petrochemical Corp. in China. A 0.5-3 l/min slipstream from a 5 tpd biomass gasifier was used to test the tar conversion system. Gas and tar were sampled before and after the tar conversion system to evaluate the effectiveness of the system. Changes in gas composition as functions of catalytic bed temperature, space velocity and steam/TOC (total organic carbon) ratio are presented. Structural changes in the catalysts during the tests are also described

  20. Catalytic oxidation of volatile organic compounds (VOCs) - A review

    Science.gov (United States)

    Kamal, Muhammad Shahzad; Razzak, Shaikh A.; Hossain, Mohammad M.

    2016-09-01

    Emission of volatile organic compounds (VOCs) is one of the major contributors to air pollution. The main sources of VOCs are petroleum refineries, fuel combustions, chemical industries, decomposition in the biosphere and biomass, pharmaceutical plants, automobile industries, textile manufacturers, solvents processes, cleaning products, printing presses, insulating materials, office supplies, printers etc. The most common VOCs are halogenated compounds, aldehydes, alcohols, ketones, aromatic compounds, and ethers. High concentrations of these VOCs can cause irritations, nausea, dizziness, and headaches. Some VOCs are also carcinogenic for both humans and animals. Therefore, it is crucial to minimize the emission of VOCs. Among the available technologies, the catalytic oxidation of VOCs is the most popular because of its versatility of handling a range of organic emissions under mild operating conditions. Due to that fact, there are numerous research initiatives focused on developing advanced technologies for the catalytic destruction of VOCs. This review discusses recent developments in catalytic systems for the destruction of VOCs. Review also describes various VOCs and their sources of emission, mechanisms of catalytic destruction, the causes of catalyst deactivation, and catalyst regeneration methods.

  1. Order of wetting transitions in electrolyte solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ibagon, Ingrid, E-mail: ingrid@is.mpg.de; Bier, Markus, E-mail: bier@is.mpg.de; Dietrich, S. [Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, 70569 Stuttgart, Germany and IV. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart (Germany)

    2014-05-07

    For wetting films in dilute electrolyte solutions close to charged walls we present analytic expressions for their effective interface potentials. The analysis of these expressions renders the conditions under which corresponding wetting transitions can be first- or second-order. Within mean field theory we consider two models, one with short- and one with long-ranged solvent-solvent and solvent-wall interactions. The analytic results reveal in a transparent way that wetting transitions in electrolyte solutions, which occur far away from their critical point (i.e., the bulk correlation length is less than half of the Debye length) are always first-order if the solvent-solvent and solvent-wall interactions are short-ranged. In contrast, wetting transitions close to the bulk critical point of the solvent (i.e., the bulk correlation length is larger than the Debye length) exhibit the same wetting behavior as the pure, i.e., salt-free, solvent. If the salt-free solvent is governed by long-ranged solvent-solvent as well as long-ranged solvent-wall interactions and exhibits critical wetting, adding salt can cause the occurrence of an ion-induced first-order thin-thick transition which precedes the subsequent continuous wetting as for the salt-free solvent.

  2. Order of wetting transitions in electrolyte solutions

    International Nuclear Information System (INIS)

    For wetting films in dilute electrolyte solutions close to charged walls we present analytic expressions for their effective interface potentials. The analysis of these expressions renders the conditions under which corresponding wetting transitions can be first- or second-order. Within mean field theory we consider two models, one with short- and one with long-ranged solvent-solvent and solvent-wall interactions. The analytic results reveal in a transparent way that wetting transitions in electrolyte solutions, which occur far away from their critical point (i.e., the bulk correlation length is less than half of the Debye length) are always first-order if the solvent-solvent and solvent-wall interactions are short-ranged. In contrast, wetting transitions close to the bulk critical point of the solvent (i.e., the bulk correlation length is larger than the Debye length) exhibit the same wetting behavior as the pure, i.e., salt-free, solvent. If the salt-free solvent is governed by long-ranged solvent-solvent as well as long-ranged solvent-wall interactions and exhibits critical wetting, adding salt can cause the occurrence of an ion-induced first-order thin-thick transition which precedes the subsequent continuous wetting as for the salt-free solvent

  3. Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems

    Energy Technology Data Exchange (ETDEWEB)

    Richard Rhudy

    2006-06-30

    -based catalyst began with almost 98% elemental mercury oxidation across the catalyst, but declined to 79% oxidation after nearly 13 months in service. The other two catalysts, an SCR-type catalyst (titanium/vanadium) and an experimental fly-ash-based catalyst, were significantly less active. The palladium-based and SCR-type catalysts were effectively regenerated at the end of the long-term test by flowing heated air through the catalyst overnight. The carbon-based catalyst was not observed to regenerate, and no regeneration tests were conducted on the fourth, fly-ash-based catalyst. Preliminary process economics were developed for the palladium and carbon-based catalysts for a scrubbed, North Dakota lignite application. As described above, the pilot-scale results showed the catalysts could not sustain 90% or greater oxidation of elemental mercury in the flue gas for a period of two years. Consequently, the economics were based on performance criteria in a later DOE NETL solicitation, which required candidate mercury control technologies to achieve at least a 55% increase in mercury capture for plants that fire lignite. These economics show that if the catalysts must be replaced every two years, the catalytic oxidation process can be 30 to 40% less costly than conventional (not chemically treated) activated carbon injection if the plant currently sells their fly ash and would lose those sales with carbon injection. If the plant does not sell their fly ash, activated carbon injection was estimated to be slightly less costly. There was little difference in the estimated cost for palladium versus the carbon-based catalysts. If the palladium-based catalyst can be regenerated to double its life to four years, catalytic oxidation process economics are greatly improved. With regeneration, the catalytic oxidation process shows over a 50% reduction in mercury control cost compared to conventional activated carbon injection for a case where the plant sells its fly ash. At Spruce Plant

  4. A Simplified Method to Calculate the Wet Bulb Globe Temperature(WBGT)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; MENG Qing-lin; ZHAO Li-hua; ZHANG Yu-feng

    2009-01-01

    Wet bulb globe temperature(WBGT) is a comprehensive index obtained mainly from three pa-rameters:black globe temperature(Tg),wet bulb temperature(Tw),and dry bulb temperature(Ta).While in field observation and numerical simulation,black globe temperature and wet bulb temperature were not easy to obtain, so WBGT was difficult to measure and calculate directly.In order to solve this problem,air dry bulb temperature, wet bulb temperature,globe temperature,relative humidity,mean air velocity,solar radiation and wet bulb globe temperature were collected during the summer(July)in Guangzhou.Correlation analysis and regression analysis were used to get a simplified method to calculate WBGT.The results showed that dry bulb temperature,relative humidity,solar radiation and WBGT were interrelated to some extent.These three pa-rameters could be used in the simplified method to predict WBGT,and the linear correlation and precision of this model were high.In addition,we used the measured data to verify the simplified method,and the results showed that the error of the calculated value and the measured value was all below 5%,which means the simpli-fied calculating method is feasible and can be used in field observation and simulation research of urban thermal environment.

  5. 允差范围内变化的房间空调器测试结果算法修正%Correcting Algorithm on Experimental Results of Room Air Conditioner Performance with Dry-bulb and Wet-bulb Temperatures Changing within Allowances

    Institute of Scientific and Technical Information of China (English)

    张忠斌; 杜垲; 黄虎; 张若楠

    2014-01-01

    提出一种求解干湿球温度在国家标准允差范围内变化的制冷量和能效比实测结果向名义工况值回归逼近的修正算法,并以制冷工况下的室内侧干湿球温度允差范围变化的房间空调器制冷量和能效比测试结果为实例进行算法修正。该算法基于制冷量和能效比实测结果,采用多元高次方程逼近求解两者的回归方程,并用贝塞尔公式验证其收敛性。运用层次分析法(Analytic hierarchy process,AHP)量化分析干湿球温度对制冷量和能效比的影响程度,进而得出在干湿球温度允差范围内制冷量和能效比的修正算法。该修正算法可对任意工况下制冷量和能效比的实测值进行修正,并以此为基础对房间空调器能效等级进行评判。修正算法能更加准确地评判房间空调器能效等级,可对现行房间空调器性能测试方法进行完善。%A correcting algorithm is provided to work out regression equations to process the experimental results of cooling capacity (CC) and energy efficiency ratio (EER) of room air conditioner(RAC) when dry-bulb and wet-bulb temperatures (D&WBTs) change in the allowances set in national standard in China. Thereby, values of CC and EER under nominal working condition can be worked out. A case of the correcting algorithm is illustrated based on the experimental results of CC and EER with indoor D&WBTs changing in the allowances under space cooling condition. Based on the experimental results, the multiple high order equation is adopted to solve the regression equations of CC and EER respectively. Bessel formula is adopted to verify the convergence. The analytic hierarchy process (AHP) is adopted to present a quantitative analysis of the D&WBTs’ influence on CC and EER;thereby, the correcting equations for CC and EER with D&WBTs changing within the allowances are obtained. Within the allowances set in the national standard, these two correcting equations

  6. Wetting transitions at soft, sliding interfaces

    Science.gov (United States)

    Martin, A.; Clain, J.; Buguin, A.; Brochard-Wyart, F.

    2002-03-01

    We observe (by optical interferometry) the contact of a rubber cap squeezing a nonwetting liquid against a plate moving at velocity U. At low velocities, the contact is dry. It becomes partially wet above a threshold velocity Vc1, with two symmetrical dry patches on the rear part. Above a second velocity Vc2, the contact is totally wet. This regime U>Vc2 corresponds to the hydroplaning of a car (decelerating on a wet road). We interpret the transitions at Vc1, Vc2 in terms of a competition between (a) liquid invasion induced by shear (b) spontaneous dewetting of the liquid (between nonwettable surfaces).

  7. Catalytic properties of niobium compounds

    International Nuclear Information System (INIS)

    The catalytic activity and selectivity of niobium compounds including oxides, salts, organometallic compounds and others are outlined. The application of these compounds as catalysts to diversified reactions is reported. The nature and action of niobium catalysts are characteristic and sometimes anomalous, suggesting the necessity of basic research and the potential use as catalysts for important processes in the chemical industry. (Author)

  8. Simple, chemoselective, catalytic olefin isomerization.

    Science.gov (United States)

    Crossley, Steven W M; Barabé, Francis; Shenvi, Ryan A

    2014-12-01

    Catalytic amounts of Co(Sal(tBu,tBu))Cl and organosilane irreversibly isomerize terminal alkenes by one position. The same catalysts effect cycloisomerization of dienes and retrocycloisomerization of strained rings. Strong Lewis bases like amines and imidazoles, and labile functionalities like epoxides, are tolerated.

  9. Hydrolysis of Miscanthus for bioethanol production using dilute acid presoaking combined with wet explosion pre-treatment and enzymatic treatment.

    Science.gov (United States)

    Sørensen, Annette; Teller, Philip J; Hilstrøm, Troels; Ahring, Birgitte K

    2008-09-01

    Miscanthus is a high yielding bioenergy crop. In this study we used acid presoaking, wet explosion, and enzymatic hydrolysis to evaluate the combination of the different pre-treatment methods for bioethanol production with Miscanthus. Acid presoaking is primarily carried out in order to remove xylose prior to wet explosion. The acid presoaking extracted 63.2% xylose and 5.2% glucose. Direct enzymatic hydrolysis of the presoaked biomass was found to give only low sugar yields of 24-26% glucose. Wet explosion is a pre-treatment method that combines wet-oxidation and steam explosion. The effect of wet explosion on non-presoaked and presoaked Miscanthus was investigated using both atmospheric air and hydrogen peroxide as the oxidizing agent. All wet explosion pre-treatments showed to have a disrupting effect on the lignocellulosic biomass, making the sugars accessible for enzymatic hydrolysis. The combination of presoaking, wet explosion, and enzymatic hydrolysis was found to give the highest sugar yields. The use of atmospheric air gave the highest xylose yield (94.9% xylose, 61.3% glucose), while hydrogen peroxide gave the highest glucose yield (82.4% xylose, 63.7% glucose). PMID:18164954

  10. Kinetics of wet peroxide oxidation of phenol with a gold/activated carbon catalyst

    OpenAIRE

    Domínguez, Carmen M.; Quintanilla, Asunción; Casas, José Antonio; Rodríguez, Juan José

    2014-01-01

    Gold nanoparticles supported on activated carbon (Au/AC) have been tested in catalytic wet peroxide oxidation using phenol as target pollutant. In the current work, the effect of several operating conditions, including initial pH (3.5–10.5), catalyst load (0–6 g/L), initial phenol concentration (0.1–5 g/L), hydrogen peroxide dose (4–100% of the theoretical stoichiometric amount) and reaction temperature (50–80 °C) has been investigated. The results show that the Au/AC catalyst would be useful...

  11. National Ignition Facility wet weather construction plan

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, A N

    1998-01-01

    This report presents a wet weather construction plan for the National Ignition Facility (NIF) construction project. Construction of the NIF commenced in mid- 1997, and excavation of the site was completed in the fall. Preparations for placing concrete foundations began in the fall, and above normal rainfall is expected over the tinter. Heavy rainfall in late November impacted foundation construction, and a wet weather construction plan was determined to be needed. This wet weather constiction plan recommends a strategy, techniques and management practices to prepare and protect the site corn wet weather effects and allow construction work to proceed. It is intended that information in this plan be incorporated in the Stormwater Pollution Prevention Plan (SWPPP) as warranted.

  12. ROE Wet Sulfate Deposition 2009-2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  13. ROE Wet Nitrate Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  14. ROE Wet Nitrate Deposition 2011-2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 2011 to 2013. Summary data in this indicator were provided by EPA’s...

  15. Tualatin River - Wet Prairie Restoration Phase III

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Forty five acres of wet prairie and 11 acres of adjacent lands were treated for reed canarygrass in this ongoing project. Federally threatened Nelson’s...

  16. Wet Chemistry of Spinel Iron oxide Particles

    OpenAIRE

    Jolivet, J.; Chanéac, C.; Prené, P.; Vayssières, L.; Tronc, E.

    1997-01-01

    Various properties of spinel iron oxide nanograins are reviewed, illustrating the broad possibilities of wet chemistry for tailoring materials for a wide range of utilizations, from catalysis and sensors to cast magnetic materials.

  17. A WET TALE: TOXICITY OF COMPLEX EFFLUENTS

    Science.gov (United States)

    This course covers standards, regulations, policy, guidance and technical aspects of implementing the whole effluent toxicity program. The curriculum incorporates rationale and information on WET test requirements from USEPA documents, such as the Technical Support Document for W...

  18. Selenium Speciation and Management in Wet FGD Systems

    Energy Technology Data Exchange (ETDEWEB)

    Searcy, K; Richardson, M; Blythe, G; Wallschlaeger, D; Chu, P; Dene, C

    2012-02-29

    This report discusses results from bench- and pilot-scale simulation tests conducted to determine the factors that impact selenium speciation and phase partitioning in wet FGD systems. The selenium chemistry in wet FGD systems is highly complex and not completely understood, thus extrapolation and scale-up of these results may be uncertain. Control of operating parameters and application of scrubber additives have successfully demonstrated the avoidance or decrease of selenite oxidation at the bench and pilot scale. Ongoing efforts to improve sample handling methods for selenium speciation measurements are also discussed. Bench-scale scrubber tests explored the impacts of oxidation air rate, trace metals, scrubber additives, and natural limestone on selenium speciation in synthetic and field-generated full-scale FGD liquors. The presence and concentration of redox-active chemical species as well as the oxidation air rate contribute to the oxidation-reduction potential (ORP) conditions in FGD scrubbers. Selenite oxidation to the undesirable selenate form increases with increasing ORP conditions, and decreases with decreasing ORP conditions. Solid-phase manganese [Mn(IV)] appeared to be the significant metal impacting the oxidation of selenite to selenate. Scrubber additives were tested for their ability to inhibit selenite oxidation. Although dibasic acid and other scrubber additives showed promise in early clear liquor (sodium based and without calcium solids) bench-scale tests, these additives did not show strong inhibition of selenite oxidation in tests with higher manganese concentrations and with slurries from full-scale wet FGD systems. In bench-tests with field liquors, addition of ferric chloride at a 250:1 iron-to-selenium mass ratio sorbed all incoming selenite to the solid phase, although addition of ferric salts had no impact on native selenate that already existed in the field slurry liquor sample. As ORP increases, selenite may oxidize to selenate more

  19. Biodegradation of wet-white leather

    OpenAIRE

    Ollé Otero, Lluís; Jorba Rafart, Montse; Font Vallès, Joaquim; Shendrik, Alexander; Bacardit Dalmases, Anna

    2011-01-01

    This paper deals with the study of the physical, chemical and biological processes associated with the deterioration of wet-white leather. The samples of leather were exposed for eight months to outdoor weathering and then their properties were subsequently evaluated. The results indicate that resistance and dimensional stability of wet-white (THPS-syntan) leather is higher than that of chrometanned leather. The comparative work with chrome leather was described earlier.

  20. Fundamental Difficulties Associated With Underwater Wet Welding

    OpenAIRE

    Joshua E. Omajene,; Jukka Martikainen

    2014-01-01

    The offshore industries carry out welding activities in the wet environment. It is evident that the wet environments possess difficulties in carrying out underwater welding. Therefore there is the need to improve the quality of weld achieved in underwater welding. This paper investigates the difficulties associated with underwater welding. The objective of this research paper is to identify and analyze the different difficulties in underwater welding so as to make a clear back...

  1. Wetting and phase separation at surfaces

    Indian Academy of Sciences (India)

    Sanjay Puri; Kurt Binder

    2005-06-01

    We study the problem of surface-directed spinodal decomposition, viz., the dynamical interplay of wetting and phase separation at surfaces. In particular, we focus on the kinetics of wetting-layer growth in a semi-infinite geometry for arbitrary surface potentials and mixture compositions. We also present representative results for phase separation in confined geometries, e.g., cylindrical pores, thin films, etc.

  2. Avalanche Dynamics in Wet Granular Materials

    OpenAIRE

    Tegzes, P.; Vicsek, T.; P. Schiffer

    2002-01-01

    We have studied the dynamics of avalanching wet granular media in a rotating drum apparatus. Quantitative measurements of the flow velocity and the granular flux during avalanches allow us to characterize novel avalanche types unique to wet media. We also explore the details of viscoplastic flow (observed at the highest liquid contents) in which there are lasting contacts during flow, leading to coherence across the entire sample. This coherence leads to a velocity independent flow depth at h...

  3. PARAMETRIC EVALUATION OF VOC CONVERSION VIA CATALYTIC INCINERATION

    Directory of Open Access Journals (Sweden)

    Kaskantzis Neto G.

    1997-01-01

    Full Text Available Abstract - A pilot-scale catalytic incineration system was used to investigate the effectiveness of catalytic incineration as a means of reducing volatile organic compound (VOC air pollutants. The objectives of the study were: 1 to investigate the effects of operating and design variables on the reduction efficiency of VOCs; and 2 to evaluate reduction efficiencies for specific compounds in different chemical classes. The study results verified that the following factors affect the catalyst performance: inlet temperature, space velocity, compound type, and compound inlet concentration. Tests showed that reduction efficiencies exceeding 98% were possible, given sufficiently high inlet gas temperatures for the following classes of compounds: alcohols, acetates, ketones, hydrocarbons, and aromatics

  4. Improvement of Heating Method for Measuring the Wetness of Flowing Wet Steam

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    In this paper,an improvement of heating method for measuring wetness of the flowing wet steam is developed,the basic principle of the heating method is presented and the mathematical model has been built for analyzing the thermodynamics problems during the process of heating,Moreover,an instrument for measuring wetness of wet steam flow was designed and made out.This instument has been used for measuring wetness of the wet steam flow at the outlet of the nozzle rig in Thermal Turbine Laboratory,Xi'an Jiaotong University,By analyzing the relative error of the result,it was found that this instrument has fairly high accuracy,it can be used as the prototype of practical instrument and has an important applicable value in engineering.

  5. Air Abrasion

    Science.gov (United States)

    ... delivered directly to your desktop! more... What Is Air Abrasion? Article Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air Abrasion for Everyone? print full article print this ...

  6. Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gary Blythe; Conor Braman; Katherine Dombrowski; Tom Machalek

    2010-12-31

    This document is the final technical report for Cooperative Agreement DE-FC26-04NT41992, 'Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems,' which was conducted over the time-period January 1, 2004 through December 31, 2010. The objective of this project has been to demonstrate at pilot scale the use of solid catalysts and/or fixed-structure mercury sorbents to promote the removal of total mercury and oxidation of elemental mercury in flue gas from coal combustion, followed by wet flue gas desulfurization (FGD) to remove the oxidized mercury at high efficiency. The project was co-funded by the U.S. DOE National Energy Technology Laboratory (DOE-NETL), EPRI, Great River Energy (GRE), TXU Energy (now called Luminant), Southern Company, Salt River Project (SRP) and Duke Energy. URS Group was the prime contractor. The mercury control process under development uses fixed-structure sorbents and/or catalysts to promote the removal of total mercury and/or oxidation of elemental mercury in the flue gas from coal-fired power plants that have wet lime or limestone FGD systems. Oxidized mercury not adsorbed is removed in the wet FGD absorbers and leaves with the byproducts from the FGD system. The project has tested candidate materials at pilot scale and in a commercial form, to provide engineering data for future full-scale designs. Pilot-scale catalytic oxidation tests have been completed for periods of approximately 14 to19 months at three sites, with an additional round of pilot-scale fixed-structure sorbent tests being conducted at one of those sites. Additionally, pilot-scale wet FGD tests have been conducted downstream of mercury oxidation catalysts at a total of four sites. The sites include the two of three sites from this project and two sites where catalytic oxidation pilot testing was conducted as part of a previous DOE-NETL project. Pilot-scale wet FGD tests were also conducted at a fifth site, but with no catalyst or fixed

  7. Ethanol-selective catalytic reduction of NO by Ag/Al2O3 catalysts: Activity and deactivation by alkali salts

    DEFF Research Database (Denmark)

    Schill, Leonhard; Putluru, Siva Sankar Reddy; Jacobsen, Casper Funk;

    2012-01-01

    Ag/Al2O3 catalysts with and without potassium doping were prepared by incipient wetness impregnation and characterized by N2 physisorption, XRPD, NH3-TPD and SEM. The influence of the Ag content from 1 to 5 wt.% was investigated for the selective catalytic reduction (SCR) of NO with ethanol. The 3...

  8. Catalytic Fast Pyrolysis: A Review

    Directory of Open Access Journals (Sweden)

    Theodore Dickerson

    2013-01-01

    Full Text Available Catalytic pyrolysis is a promising thermochemical conversion route for lignocellulosic biomass that produces chemicals and fuels compatible with current, petrochemical infrastructure. Catalytic modifications to pyrolysis bio-oils are geared towards the elimination and substitution of oxygen and oxygen-containing functionalities in addition to increasing the hydrogen to carbon ratio of the final products. Recent progress has focused on both hydrodeoxygenation and hydrogenation of bio-oil using a variety of metal catalysts and the production of aromatics from bio-oil using cracking zeolites. Research is currently focused on developing multi-functional catalysts used in situ that benefit from the advantages of both hydrodeoxygenation and zeolite cracking. Development of robust, highly selective catalysts will help achieve the goal of producing drop-in fuels and petrochemical commodities from wood and other lignocellulosic biomass streams. The current paper will examine these developments by means of a review of existing literature.

  9. Combined catalytic converter and afterburner

    Energy Technology Data Exchange (ETDEWEB)

    Ma, T.T.-H.

    1994-11-30

    This patent describes the combined use of a catalytic converter and afterburner. An afterburner chamber and a catalyst matrix are disposed in series within a casing. A combustible premixed charge is ignited in the afterburner chamber before it enters the catalyst matrix. This invention overcomes the problem encountered in previous designs of some of the premixed charge passing unreacted through the device unless a very long afterburner chamber is used. (UK)

  10. Thermodynamics of catalytic nanoparticle morphology

    Science.gov (United States)

    Zwolak, Michael; Sharma, Renu; Lin, Pin Ann

    Metallic nanoparticles are an important class of industrial catalysts. The variability of their properties and the environment in which they act, from their chemical nature & surface modification to their dispersion and support, allows their performance to be optimized for many chemical processes useful in, e.g., energy applications and other areas. Their large surface area to volume ratio, as well as varying sizes and faceting, in particular, makes them an efficient source for catalytically active sites. These characteristics of nanoparticles - i.e., their morphology - can often display intriguing behavior as a catalytic process progresses. We develop a thermodynamic model of nanoparticle morphology, one that captures the competition of surface energy with other interactions, to predict structural changes during catalytic processes. Comparing the model to environmental transmission electron microscope images of nickel nanoparticles during carbon nanotube (and other product) growth demonstrates that nickel deformation in response to the nanotube growth is due to a favorable interaction with carbon. Moreover, this deformation is halted due to insufficient volume of the particles. We will discuss the factors that influence morphology and also how the model can be used to extract interaction strengths from experimental observations.

  11. The role of bio-inspired hierarchical structures in wetting.

    Science.gov (United States)

    Grewal, H S; Cho, Il-Joo; Yoon, Eui-Sung

    2015-04-01

    Superhydrophobicity facilitates the development of self-cleaning, anti-biofouling, and anti-corrosion surfaces. The leaves of the lotus (Nelumbo nucifera) and taro (Colocasia esculenta) plants are well known for their self-cleaning properties. A hierarchical structure comprising papillae epidermal cells superimposed with epicuticular wax crystalloids of varying shapes, sizes, and orientations is an important aspect of the surface of these plant leaves. We fabricated two types of hierarchical structures biomimicking the surface topography of the lotus leaf. The hierarchical patterns successfully demonstrated the superhydrophobic state in comparison with nano and micro patterns. We used the finite element method (FEM) to simulate and understand the wetting process. The FEM simulations showed good correlation with the experimental results. FEM was helpful in understanding the wetting of enormously complex biological surfaces with relative ease, and it qualifies as a potential tool for designing superhydrophobic surfaces. Using the FEM framework, we further designed surfaces to optimize the order of the shapes in hierarchy. The results showed that the superhydrophobic surface with the lowest wetted area was obtained by placing shapes with smaller geometric angles at the top of the hierarchy. This arrangement of shapes provides the optimum combination of superhydrophobicity and surface integrity. This observation explains why the hierarchical structure of many superhydrophobic leaves follows this order. We also investigated the complex hierarchical structure of Salvinia minima. Owing to its remarkable ability to entrap air and pin the contact line, it exhibits superhydrophobicity along with the much-required Cassie state. These properties of Salvinia minima make it an excellent candidate for developing omniphobic surfaces. PMID:25856043

  12. The Analysis of Characteristics in Dry and Wet Environments of Silicon Nanowire-Biosensor.

    Science.gov (United States)

    Choi, Hyoun Mo; Shin, Dong Jae; Lee, Jung Han; Mo, Hyun-Sun; Park, Tae Jung; Park, Byung-Gook; Kim, Dong Myong; Choi, Sung-Jin; Kim, Dae Hwan; Park, Jisun

    2016-05-01

    Our study investigates differences in sensitivity of dry and wet environment in the field of biosensing experiment in detail and depth. The sensitivity of biosensing varies by means of surrounding conditions of silicon nanowire field effect transistor (SiNW FET). By examining charged polymer reaction in the silicon nanowire transistor (SiNW), we have discovered that the threshold voltage (V(T)) shift and change of subthreshold slope (SS) in wet environment are smaller than that of the air. Furthermore, we analyzed the sensitivity through modifying electrolyte concentration in the wet condition, and confirmed that V(T) shift increases in low concentration condition of phosphate buffered saline (PBS) due to the Debye length. We believe that the results we have found in this study would be the cornerstone in contributing to advanced biosensing experiment in the future.

  13. Assessing wet snow avalanche activity using detailed physics based snowpack simulations

    Science.gov (United States)

    Wever, N.; Vera Valero, C.; Fierz, C.

    2016-06-01

    Water accumulating on microstructural transitions inside a snowpack is often considered a prerequisite for wet snow avalanches. Recent advances in numerical snowpack modeling allow for an explicit simulation of this process. We analyze detailed snowpack simulations driven by meteorological stations in three different climate regimes (Alps, Central Andes, and Pyrenees), with accompanying wet snow avalanche activity observations. Predicting wet snow avalanche activity based on whether modeled water accumulations inside the snowpack locally exceed 5-6% volumetric liquid water content is providing a higher prediction skill than using thresholds for daily mean air temperature, or the daily sum of the positive snow energy balance. Additionally, the depth of the maximum water accumulation in the simulations showed a significant correlation with observed avalanche size. Direct output from detailed snow cover models thereby is able to provide a better regional assessment of dangerous slope aspects and potential avalanche size than traditional methods.

  14. The Analysis of Characteristics in Dry and Wet Environments of Silicon Nanowire-Biosensor.

    Science.gov (United States)

    Choi, Hyoun Mo; Shin, Dong Jae; Lee, Jung Han; Mo, Hyun-Sun; Park, Tae Jung; Park, Byung-Gook; Kim, Dong Myong; Choi, Sung-Jin; Kim, Dae Hwan; Park, Jisun

    2016-05-01

    Our study investigates differences in sensitivity of dry and wet environment in the field of biosensing experiment in detail and depth. The sensitivity of biosensing varies by means of surrounding conditions of silicon nanowire field effect transistor (SiNW FET). By examining charged polymer reaction in the silicon nanowire transistor (SiNW), we have discovered that the threshold voltage (V(T)) shift and change of subthreshold slope (SS) in wet environment are smaller than that of the air. Furthermore, we analyzed the sensitivity through modifying electrolyte concentration in the wet condition, and confirmed that V(T) shift increases in low concentration condition of phosphate buffered saline (PBS) due to the Debye length. We believe that the results we have found in this study would be the cornerstone in contributing to advanced biosensing experiment in the future. PMID:27483843

  15. Development studies for a novel wet oxidation process

    Energy Technology Data Exchange (ETDEWEB)

    Dhooge, P.M.; Hakim, L.B.

    1994-01-01

    A catalytic wet oxidation process (DETOX), which uses an acidic iron solution to oxidize organic compounds to carbon dioxide, water, and other simple products, was investigated as a potential method for the treatment of multicomponent hazardous and mixed wastes. The organic compounds picric acid, poly(vinyl chloride), tetrachlorothiophene, pentachloropyridine, Aroclor 1260 (a polychlorinated biphenyl), and hexachlorobenzene were oxidized in 125 ml reaction vessels. The metals arsenic, barium, beryllium, cadmium, cerium (as a surrogate for plutonium), chromium, lead, mercury, neodymium (as a surrogate for uranium), nickel, and vanadium were tested in the DETOX solution. Barium, beryllium, cerium, chromium, mercury, neodymium, nickel, and vanadium were all found to be very soluble (>100 g/l) in the DETOX chloride-based solution. Arsenic, barium, cadmium, and lead solubilities were lower. Lead could be selectively precipitated from the DETOX solution. Chromium(VI) was reduced to relatively non-toxic chromium(III) by the solution. Six soils were contaminated with arsenic, barium, beryllium, chromium, lead, and neodymium oxides at approximately 0.1% by weight, and benzene, trichloroethene, mineral oil, and Aroclor 1260 at approximately 5% by weight total, and 5.g amounts treated with the DETOX solution in unstirred 125. ml reaction bombs. It is felt that soil treatment in a properly designed system is entirely possible despite incomplete oxidation of the less volatile organic materials in these unstirred tests.

  16. Quantum confinement of lead titanate nanocrystals by wet chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Kaviyarasu, K., E-mail: kaviyarasuloyolacollege@gmail.com [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P O Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), Materials Research Department (MSD), iThemba LABS-National Research Foundation - NRF, 1 Old Faure Road, 7129, P O Box 722, Somerset West, Western Cape Province (South Africa); Manikandan, E., E-mail: maniphysics@gmail.com [Nanosciences African Network (NANOAFNET), Materials Research Department (MSD), iThemba LABS-National Research Foundation - NRF, 1 Old Faure Road, 7129, P O Box 722, Somerset West, Western Cape Province (South Africa); Central Research Laboratory, Sree Balaji Medical College & Hospital, Bharath University, Chrompet, Chennai, Tamil Nadu (India); Nuru, Z.Y. [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P O Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), Materials Research Department (MSD), iThemba LABS-National Research Foundation - NRF, 1 Old Faure Road, 7129, P O Box 722, Somerset West, Western Cape Province (South Africa); Maaza, M., E-mail: likmaaz@gmail.com [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P O Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), Materials Research Department (MSD), iThemba LABS-National Research Foundation - NRF, 1 Old Faure Road, 7129, P O Box 722, Somerset West, Western Cape Province (South Africa)

    2015-11-15

    Lead Titanate (PbTiO{sub 3)} is a category of the practical semiconductor metal oxides, which is widely applied in various scientific and industrial fields because of its catalytic, optical, and electrical properties. PbTiO{sub 3} nanocrystalline materials have attracted a wide attention due to their unique properties. PbTiO{sub 3} nanocrystals were investigated by X-ray diffraction (XRD) to identify the PbTiO{sub 3} nanocrystals were composed a tetragonal structure. The diameter of a single sphere was around 20 nm and the diameter reached up to 3 μm. The chemical composition of the samples and the valence states of elements were determined by X-ray photoelectron spectroscopy (XPS) in detail. - Highlights: • Single crystalline NSs of PbTiO{sub 3} fabricated by wet chemical method. • PbTiO{sub 3} NSs were uniform and continuous along the long axis. • Tetragonal perovskite structure with the diameter 20 nm and length 3 μm. • XPS spectrum was fitted with Lorentzian function respectively. • The size of the images is also 10 μm × 10 μm.

  17. Quantum confinement of lead titanate nanocrystals by wet chemical method

    International Nuclear Information System (INIS)

    Lead Titanate (PbTiO3) is a category of the practical semiconductor metal oxides, which is widely applied in various scientific and industrial fields because of its catalytic, optical, and electrical properties. PbTiO3 nanocrystalline materials have attracted a wide attention due to their unique properties. PbTiO3 nanocrystals were investigated by X-ray diffraction (XRD) to identify the PbTiO3 nanocrystals were composed a tetragonal structure. The diameter of a single sphere was around 20 nm and the diameter reached up to 3 μm. The chemical composition of the samples and the valence states of elements were determined by X-ray photoelectron spectroscopy (XPS) in detail. - Highlights: • Single crystalline NSs of PbTiO3 fabricated by wet chemical method. • PbTiO3 NSs were uniform and continuous along the long axis. • Tetragonal perovskite structure with the diameter 20 nm and length 3 μm. • XPS spectrum was fitted with Lorentzian function respectively. • The size of the images is also 10 μm × 10 μm

  18. Noble metal/functionalized cellulose nanofiber composites for catalytic applications.

    Science.gov (United States)

    Gopiraman, Mayakrishnan; Bang, Hyunsik; Yuan, Guohao; Yin, Chuan; Song, Kyung-Hun; Lee, Jung Soon; Chung, Ill Min; Karvembu, Ramasamy; Kim, Ick Soo

    2015-11-01

    In this study, cellulose acetate nanofibers (CANFs) with a mean diameter of 325 ± 2.0 nm were electrospun followed by deacetylation and functionalization to produce anionic cellulose nanofibers (f-CNFs). The noble metal nanoparticles (RuNPs and AgNPs) were successfully decorated on the f-CNFs by a simple wet reduction method using NaBH4 as a reducing agent. TEM and SEM images of the nanocomposites (RuNPs/CNFs and AgNPs/CNFs) confirmed that the very fine RuNPs or AgNPs were homogeneously dispersed on the surface of f-CNFs. The weight percentage of the Ru and Ag in the nanocomposites was found to be 13.29 wt% and 22.60 wt% respectively; as confirmed by SEM-EDS analysis. The metallic state of the Ru and Ag in the nanocomposites was confirmed by XPS and XRD analyses. The usefulness of these nanocomposites was realized from their superior catalytic activity. In the aerobic oxidation of benzyl alcohol to benzaldehyde, the RuNPs/CNFs system gave a better yield of 89% with 100% selectivity. Similarly, the AgNPs/CNFs produced an excellent yield of 99% (100% selectivity) in the aza-Michael reaction of 1-phenylpiperazine with acrylonitrile. Mechanism has been proposed for the catalytic systems. PMID:26256382

  19. Catalytical degradation of relevant pollutants from waters using magnetic nanocatalysts

    Science.gov (United States)

    Nadejde, C.; Neamtu, M.; Schneider, R. J.; Hodoroaba, V.-D.; Ababei, G.; Panne, U.

    2015-10-01

    The catalytic efficiency of two magnetically responsive nanocatalysts was evaluated for the degradation of Reactive Black 5 (RB5) and Reactive Yellow 84 (RY84) azo dyes using hydrogen peroxide as oxidant under very mild conditions (atmospheric pressure, room temperature). In order to obtain the nanocatalysts, the surface of magnetite (Fe3O4) nanoparticles, prepared by a co-precipitation method, was further modified with ferrous oxalate, a highly sensitive non-hazardous reducing agent. The sensitized nanomaterials were characterized by X-ray diffraction, scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy and vibrating sample magnetometry, and used in the catalytic wet hydrogen peroxide oxidation (CWHPO) of RB5 and RY84, in laboratory-scale experiments. The effect of important variables such as catalyst dosage, H2O2 concentration, and contact time was studied in the dye degradation kinetics. The results showed that it was possible to remove up to 99.7% dye in the presence of 20 mM H2O2 after 240 min of oxidation for a catalyst concentration of 10 g L-1 at 25 °C and initial pH value of 9.0. CWHPO of reactive dyes using sensitized magnetic nanocatalysts can be a suitable pre-treatment method for complete decolorization of effluents from textile dyeing and finishing processes, once the optimum operating conditions are established.

  20. Recent developments in research on catalytic reaction networks

    Directory of Open Access Journals (Sweden)

    Roberto Serra

    2013-09-01

    Full Text Available Over the last years, analyses performed on a stochastic model of catalytic reaction networks have provided some indications about the reasons why wet-lab experiments hardly ever comply with the phase transition typically predicted by theoretical models with regard to the emergence of collectively self-replicating sets of molecule (also defined as autocatalytic sets, ACSs, a phenomenon that is often observed in nature and that is supposed to have played a major role in the emergence of the primitive forms of life. The model at issue has allowed to reveal that the emerging ACSs are characterized by a general dynamical fragility, which might explain the difficulty to observe them in lab experiments. In this work, the main results of the various analyses are reviewed, with particular regard to the factors able to affect the generic properties of catalytic reactions network, for what concerns, not only the probability of ACSs to be observed, but also the overall activity of the system, in terms of production of new species, reactions and matter.

  1. Plasma coating formed TIO2 catalysts usage in cleaning the air from nitrogen oxides and carbon monoxide

    OpenAIRE

    Vitalij Kolodynskij; Pranas Baltrėnas

    2015-01-01

    The present catalytic air purification device–air cleaning device is capable to reduce nitrogen oxide sand carbon monoxide concentrations in polluted air stream and to achieve high cleaning efficiency. The principle of operation of catalytic air cleaning device is based on plasma coating formed catalysts usage. At high temperatures and oxygen concentrations in the experimental device channel, catalysts become active and reactions of conversion of pollutants start. In this research, the effici...

  2. Tunable Reactive Wetting of Sn on Microporous Cu Layer

    Institute of Scientific and Technical Information of China (English)

    Qingquan Lai; Lei Zhang; Cai Chen; J.K. Shang

    2012-01-01

    Wetting of microporous Cu layer by liquid Sn resulted in contact angles from 0 to 33 deg., tunable by varying wetting temperature and porous microstructure. The wetting was dominated by the interracial metallurgical reaction, which can lead to pore closure phenomenon, as the liquid infiltration facilitating the wetting process.

  3. Energy and heat balance in wet DCT

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, Viren; Moser, Alexander; Schaefer, Michael; Ritschel, Michael [BorgWarner Drivetrain Engineering GmbH, Ketsch (Germany)

    2012-11-01

    Wet clutch systems are well known for their thermal robustness and versatility in a wide range of automotive applications. Conventional automatics have used them for a long time as torque converter lock-up clutches, shift elements and launch clutches. With the development of DCTs, wet clutch technology has evolved in terms of launch and shift performance, controllability, robustness and efficiency. This paper discusses improvements in the wet clutch and their impact on today's vehicle applications in terms of heat and energy management. Thermal robustness is a crucial aspect for an automatic transmission. In addition to the clutch thermal performance, the influence of transmission oil cooler and oil sump warm-up behavior are discussed. Based on our latest development activities, test results and simulations, we shall discuss the latest friction material enhancement and its impact on DCTs in terms of efficiency and performance. Drag loss is a much-discussed topic during the development of wet clutch systems. This paper discusses in detail the cause and break-up of various energy losses in a wet DCT. Efficient energy management strategies for actuation systems, cooling, and lubrication, clutch apply, and pre-selection in modern power trains with engine start / stop are evaluated based on the latest test and simulation results. Finally, the paper summarizes the performance and efficiency optimized moist clutch system. (orig.)

  4. Performance of some surfactants as wetting agents

    Energy Technology Data Exchange (ETDEWEB)

    Shalaby, M.N.; El-Shanny, O.A.A. [Egyptian Petroleum Research Institute (EPRI), Cairo (Egypt). Evaluation and Analysis Dept.

    2005-12-01

    The wetting power of anionic surfactant: sodium dodecyl sulfate (SDS), and nonionic surfactants: polyoxyethelene(14)monolaurate [La(EO){sub 14}] and polyoxyethelene(14)monoeleate [OI(EO){sub 14}] has been studied to determine their performance as wetting agents. The study reveals that the nonionic compound with a long hydrophobic chain exhibits higher wettability than the shorter one when used at very low cocentrations (below CMC) and the reverse is shown with high concentrations (above CMC). the wetting power of the investigated surfactants increases as the CMC values increases. In case of the nonionic compounds and at surfactant concentrations equal their CMC values, OI(EO){sub 14} shows a higher wetting power than La(EO){sub 14} while is possesses a lower HLB value. The anionic surfactant shows an optimum wetting in comparison with the tested nonionic one. The wettability of all the investigated samples increases as the surface tension of their solutions increases to the allowed limit that can be reached in the presence of surfactant. (orig.)

  5. Wetting and adsorption modification in the system

    Directory of Open Access Journals (Sweden)

    Yuliya Bogdanova

    2015-09-01

    Full Text Available Regularities of wetting and adsorption modification of surfaces of continual membranes made from highly permeable glassy polymers poly[1-(trimethylsilyl-1-propyne] (PTMSP and poly(4-methyl-2-pentyn (PMP with aqueous ethanol solutions and alcohol solutions containing organic dyes (Solvent Blue 35 and Remazol Brilliant Blue were investigated. Isotherms of stress wetting of polymer membrane surface by etanol solutions were found out to have maximums in the range of concentrations corresponding to the beginning of liquid sorption into the membrane and polymer swelling. Thus, the principal possibility of optimization of nanofiltration experiments by liquid wetting angle measurements on continuous polymer membrane surfaces was shown. The presence of the dye was shown not to affect PMP wetting. But in the case of PTMSP, it leads to shear of the maximum of stress wetting isotherms to the range of higher concentrations. It was found out the effectiveness of the adsorption surface modification of continuous polymer membrane surfaces by ethanol solutions containing dyes does not dependent on chemical nature of the dye. At the same time, there are different trends in the energy characteristics of the membrane surface.

  6. WET STRENGTH PAPER REPULPING: LABORATORY EVALUATION

    Institute of Scientific and Technical Information of China (English)

    NishiK.Bhardwaj; VikasRajan; A.G.Kulkarni

    2004-01-01

    The recycling of wet strength papers in a normal recycling mill is often troublesome due to the severe operating conditions required to defibre wet strength papers. The various methods are presented which will quickly allow mills to determine the most effective pulping aids to use when repulping wet strength papers. The repulping of wet strength paper with inorganic chemicals was investigated in the laboratory. The effects of major variables, that is, repulping time, pulp consistency, soaking time, temperature, and reactant concentration in the repulping stage were examined using Plackett-Burman design. The repulping time was the most crucial & influential process variable affecting repulping characteristic and formation related properties. The more significant repulping process variables affecting pulp yield were repulping time, soaking temperature and pulp consistency whereas for formation index and feature size, repulping time, pulp consistency, soaking temperature and time were the more important variables. The formation index is increased by an increase in repulping time, pulp consistency and soaking time whereas the feature size is decreased by an increase in repulping time, soaking temperature and pulp consistency. The formation index and the rejects were more sensitive to changes in process variables than were the feature size or the pulp yield. The pulp recycled from wet strength waste paper had good physical strength properties.

  7. WET STRENGTH PAPER REPULPING:LABORATORY EVALUATION

    Institute of Scientific and Technical Information of China (English)

    Nishi K. Bhardwaj; Vikas Rajan; A.G. Kulkarni

    2004-01-01

    The recycling of wet strength papers in a normal recycling mill is often troublesome due to the severe operating conditions required to defibre wet strength papers. The various methods are presented which will quickly allow mills to determine the most effective pulping aids to use when repulping wet strength papers. The repulping of wet strength paper with inorganic chemicals was investigated in the laboratory. The effects of major variables, that is,repulping time, pulp consistency, soaking time,temperature, and reactant concentration in the repulping stage were examined using Plackett-Burman design. The repulping time was the most crucial & influential process variable affecting repulping characteristic and formation related properties. The more significant repulping process variables affecting pulp yield were repulping time,soaking temperature and pulp consistency whereas for formation index and feature size, repulping time,pulp consistency, soaking temperature and time were the more important variables. The formation index is increased by an increase in repulping time, pulp consistency and soaking time whereas the feature size is decreased by an increase in repulping time,soaking temperature and pulp consistency. The formation index and the rejects were more sensitive to changes in process variables than were the feature size or the pulp yield. The pulp recycled from wet strength waste paper had good physical strength properties.

  8. Wetting films on chemically patterned surfaces.

    Science.gov (United States)

    Karakashev, Stoyan I; Stöckelhuber, Klaus W; Tsekov, Roumen

    2011-11-15

    The behavior of thin wetting films on chemically patterned surfaces was investigated. The patterning was performed by means of imprinting of micro-grid on methylated glass surface with UV-light (λ=184.8 nm). Thus imprinted image of the grid contained hydrophilic cells and hydrophobic bars on the glass surface. For this aim three different patterns of grids were utilized with small, medium and large size of cells. The experiment showed that the drainage of the wetting aqueous films was not affected by the type of surface patterning. However, after film rupturing in the cases of small and medium cells of the patterned grid the liquid from the wetting film underwent fast self-organization in form of regularly ordered droplets covering completely the cells of the grid. The droplets reduced significantly their size upon time due to evaporation. In the cases of the largest cell grid, a wet spot on the place of the imprinted grid was formed after film rupturing. This wet spot disassembled slowly in time. In addition, formation of a periodical zigzag three-phase contact line (TPCL) was observed. This is a first study from the planned series of studies on this topic. PMID:21875710

  9. Design consideration for wet welded joints

    Energy Technology Data Exchange (ETDEWEB)

    Szelagowski, P.; Osthus, V. [GKSS Research Center, Geesthacht (Germany); Petershagen, H.; Pohl, R. [Univ. Hamburg (Germany). Inst. fuer Schiffbau; Lafaye, G. [Stolt Comex Seaway S.A., Marseille (France)

    1996-12-01

    Wet welding has become a joining technique that under certain circumstances can provide results which cannot be distinguished between wet or dry production and the achievable mechanical quality is comparable to dry atmospheric welds. Wet welding is not a process which can be applied easily and which can be properly handled by untrained diver welders. Wet welding is more than any other kind of welding process or procedure a joining technique that requires the full job-concentration and -knowledge of an excellent trained and skilled diver welder throughout the whole production time, who is 100% identifying himself with his task. Furthermore he must be fully aware of the production requirements and possible metallurgical/environmental reactions and outcomes. He must be able to be fully concentrated on the process performance throughout his total work shift. In short: he must be an outstanding expert in his field. The following paper will highlight these subjects and show the necessity of their exact observation to achieve excellent quality in wet welding.

  10. Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

    NARCIS (Netherlands)

    Klaassen, W.

    2001-01-01

    Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules f

  11. A review of liquid-phase catalytic hydrodechlorination

    Directory of Open Access Journals (Sweden)

    Alba Nelly Ardila Arias

    2010-04-01

    Full Text Available This survey was aimed at introducing the effect of light organochlorinated compound emissions on the envi-ronment, particularly on water, air, soil, biota and human beings. The characteristics and advantages of liquid phase catalytic hydrodechlorination as a technology for degrading these chlorinated compounds is also outlined and the main catalysts used in the hydrodechlorination process are described. Special emphasis is placed on palladium catalysts, their activity, the nature of active species and deactivation. The effect of several parameters is introduced, such as HCl, solvent, base addition and type of reducing agent used. The main results of kinetic studies, reactors used and the most important survey conclusions are presented.

  12. Power generation characteristics of tubular type SOFC by wet process

    Energy Technology Data Exchange (ETDEWEB)

    Tajiri, H.; Nakayama, T. [Kyushu Electric Power Company, Inc., Fukuoka (Japan); Kuroishi, M. [TOTO Ltd., Kanagawa (Japan)] [and others

    1996-12-31

    The development of a practical solid oxide fuel cell requires improvement of a cell performance and a cell manufacturing technology suitable for the mass production. In particular tubular type SOFC is thought to be superior in its reliability because its configuration can avoid the high temperature sealing and reduce the thermal stress resulting from the contact between cells. The authors have fabricated a tubular cell with an air electrode support by a wet processing technique, which is suitable for mass production in improving a power density. To enhance the power output of the module, the Integrated Tubular-Type (ITT) cell has been developed. This paper reports the performance of the single cells with various active anode areas and the bundle with series-connected 9-ITT cells with an active anode area of 840 cm{sup 2}.

  13. Catalytic partial oxidation of methane over porous silica supported VO{sub x} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Pirovano, C.; Schoenborn, E.; Kalevaru, V.N.; Wohlrab, S.; Luecke, B.; Martin, A. [University Rostock e.V., Rostock (Germany). Leibniz Inst. for Catalysis

    2011-07-01

    High surface area mesoporous siliceous MCM-41 and SBA-15 materials have been used as supports to disperse vanadium oxide species using wet impregnation and incipient wetness impregnation methods. These materials were used as catalysts for the partial oxidation of methane (POM) to formaldehyde. The physico-chemical properties of the solids were studied by means of BET, DR-UV/Vis spectroscopy, Py-FTIR and TEM. The influence of support and the preparation method on the dispersion of VOx is also investigated. The catalytic properties of the catalysts were examined in a fixed bed stainless steel reactor at 923 K. So far a maximum production of formaldehyde can be detected on SBA-15 supported VOx-catalysts prepared by incipient wetness impregnation. On this V/SBA-15 material a covalent attachment of catalytic active molecular vanadium species dominates, which in turn leads to a lower activation temperature and thereby reduced over-oxidation. From the best case, the space time yield of HCHO could be reached close to 775 g{sub HCHO} Kg{sub cat}{sup -1} h{sup -1}. (orig.)

  14. Molecular Dynamics Simulations for Predicting Surface Wetting

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2014-06-01

    Full Text Available The investigation of wetting of a solid surface by a liquid provides important insights; the contact angle of a liquid droplet on a surface provides a quantitative measurement of this interaction and the degree of attraction or repulsion of that liquid type by the solid surface. Molecular dynamics (MD simulations are a useful way to examine the behavior of liquids on solid surfaces on a nanometer scale. Thus, we surveyed the state of this field, beginning with the fundamentals of wetting calculations to an examination of the different MD methodologies used. We highlighted some of the advantages and disadvantages of the simulations, and look to the future of computer modeling to understand wetting and other liquid-solid interaction phenomena.

  15. Handling of wet residues in industry

    DEFF Research Database (Denmark)

    Villanueva, Alejandro

    , to remove from it the substances which presence impedes reusing the water. These substances accumulate in a by-product called wet residue. An integral part of water recycling projects in the industry is the handling and disposal of the wet residues generated. The treatment, utilisation and disposal of wet......In countries with high prices of fresh water use and wastewater discharge, water recycling has become an alternative to traditional water consumption and discharge for industries with water-based processes. Industrial water recycling means in many cases that water has to be treated and cleaned...... residues depend totally on the industrial sector of origin and the composition of the water to be recycled. Treatment is more problematic in some cases than in others, but in all water recycling applications it is an issue of concern. The present study addresses this concern by providing a package...

  16. Wetted-region structure in horizontal unsaturated fractures: Water entry through the surrounding porous matrix

    International Nuclear Information System (INIS)

    Small-scale processes that influence wetted structure within the plane of a horizontal fracture as the fracture wets or drains through the matrix are investigated. Our approach integrates both aperture-scale modeling and physical experimentation. Several types of aperture-scale models have been defined and implemented. A series of physical experimental systems that allow us to measure wetted-region structure as a function of system parameters and water pressure head in analogue fractures also have been designed. In our preliminary proof-of-concept experiment, hysteresis is clearly evident in the measured saturation/pressure relation, as is the process of air entrapment, which causes a reduction in the connected areas between blocks and the wetted region available for flow in the plane of the fracture. A percolation threshold where the system is quickly spanned, allowing fluid conduction in the fracture plane, is observed which is analogous to that found in the aperture-scale models. A fractal wetted and entrapped-region structure is suggested by both experiment and modeling. This structure implies that flow tortuosity for both flow in the fracture and for inter-block fluid transfer is a scale-dependent function of pressure head

  17. Wet scrubbing of biomass producer gas tars using vegetable oil

    Science.gov (United States)

    Bhoi, Prakashbhai Ramabhai

    The overall aims of this research study were to generate novel design data and to develop an equilibrium stage-based thermodynamic model of a vegetable oil based wet scrubbing system for the removal of model tar compounds (benzene, toluene and ethylbenzene) found in biomass producer gas. The specific objectives were to design, fabricate and evaluate a vegetable oil based wet scrubbing system and to optimize the design and operating variables; i.e., packed bed height, vegetable oil type, solvent temperature, and solvent flow rate. The experimental wet packed bed scrubbing system includes a liquid distributor specifically designed to distribute a high viscous vegetable oil uniformly and a mixing section, which was designed to generate a desired concentration of tar compounds in a simulated air stream. A method and calibration protocol of gas chromatography/mass spectroscopy was developed to quantify tar compounds. Experimental data were analyzed statistically using analysis of variance (ANOVA) procedure. Statistical analysis showed that both soybean and canola oils are potential solvents, providing comparable removal efficiency of tar compounds. The experimental height equivalent to a theoretical plate (HETP) was determined as 0.11 m for vegetable oil based scrubbing system. Packed bed height and solvent temperature had highly significant effect (p0.05) effect on the removal of model tar compounds. The packing specific constants, Ch and CP,0, for the Billet and Schultes pressure drop correlation were determined as 2.52 and 2.93, respectively. The equilibrium stage based thermodynamic model predicted the removal efficiency of model tar compounds in the range of 1-6%, 1-4% and 1-2% of experimental data for benzene, toluene and ethylbenzene, respectively, for the solvent temperature of 30° C. The NRTL-PR property model and UNIFAC for estimating binary interaction parameters are recommended for modeling absorption of tar compounds in vegetable oils. Bench scale

  18. The effect of noble metals on catalytic methanation reaction over supported Mn/Ni oxide based catalysts

    OpenAIRE

    Wan Azelee Wan Abu Bakar; Rusmidah Ali; Nurul Shafeeqa Mohammad

    2015-01-01

    Carbon dioxide (CO2) in sour natural gas can be removed using green technology via catalytic methanation reaction by converting CO2 to methane (CH4) gas. Using waste to wealth concept, production of CH4 would increase as well as creating environmental friendly approach for the purification of natural gas. In this research, a series of alumina supported manganese–nickel oxide based catalysts doped with noble metals such as ruthenium and palladium were prepared by wetness impregnation method. T...

  19. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.

    2012-08-07

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  20. Controllable underwater anisotropic oil-wetting

    Energy Technology Data Exchange (ETDEWEB)

    Yong, Jiale; Chen, Feng, E-mail: chenfeng@mail.xjtu.edu.cn; Yang, Qing; Farooq, Umar; Bian, Hao; Du, Guangqing; Hou, Xun [State Key Laboratory for Manufacturing System Engineering and Key Laboratory of Photonics Technology for Information of Shaanxi Province, School of Electronics and Information Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2014-08-18

    This Letter demonstrates a simple method to achieve underwater anisotropic oil-wetting using silicon surfaces with a microgroove array produced by femtosecond laser ablation. The oil contact angles along the direction perpendicular to the grooves are consistently larger than those parallel to the microgroove arrays in water because the oil droplet is restricted by the energy barrier that exists between the non-irradiated domain and the trapped water in the laser-ablated microgrooves. This underwater anisotropic oil-wetting is able to be controlled, and the anisotropy can be tuned from 0° to ∼20° by adjusting the period of the microgroove arrays.

  1. Equilibrating nanoparticle monolayers using wetting films.

    Science.gov (United States)

    Pontoni, Diego; Alvine, Kyle J; Checco, Antonio; Gang, Oleg; Ocko, Benjamin M; Pershan, Peter S

    2009-01-01

    Monolayers of bimodal gold nanoparticles on silicon are investigated by a combination of microscopy (dry monolayers) and x-ray diffraction (dry and wet monolayers). In the presence of an excess of small particles, the nanoscale packing structure closely resembles the small-particle-rich scenario of the structural crossover transition that has been predicted and also observed with micron-scale hard-sphere colloids. Structural morphology is monitored in situ during monolayer dissolution and reassembly within the thin liquid wetting film. This approach allows investigation of size and solvent effects on nanoparticles in quasi-two-dimensional confinement. PMID:19257214

  2. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    Directory of Open Access Journals (Sweden)

    S. J. Solomon

    2005-05-01

    Full Text Available A novel atmospheric methanol measurement technique, employing selective gas-phase catalytic conversion of methanol to formaldehyde followed by detection of the formaldehyde product, has been developed and tested. The effects of temperature, gas flow rate, gas composition, reactor-bed length, and reactor-bed composition on the methanol conversion efficiency of a molybdenum-rich, iron-molybdate catalyst [Mo-Fe-O] were studied. Best results were achieved using a 1:4 mixture (w/w of the catalyst in quartz sand. Optimal methanol to formaldehyde conversion (>95% efficiency occurred at a catalyst housing temperature of 345°C and an estimated sample-air/catalyst contact time of <0.2 s. Potential interferences arising from conversion of methane and a number of common volatile organic compounds (VOC to formaldehyde were found to be negligible under most atmospheric conditions and catalyst housing temperatures. Using the new technique, atmospheric measurements of methanol were made at the University of Bremen campus from 1 to 15 July 2004. Methanol mixing ratios ranged from 1 to 5 ppb with distinct maxima at night. Formaldehyde mixing ratios, obtained in conjunction with methanol by periodically bypassing the catalytic converter, ranged from 0.2 to 1.6 ppb with maxima during midday. These results suggest that selective, catalytic methanol to formaldehyde conversion, coupled with existing formaldehyde measurement instrumentation, is an inexpensive and effective means for monitoring atmospheric methanol.

  3. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    Directory of Open Access Journals (Sweden)

    S. J. Solomon

    2005-01-01

    Full Text Available A novel atmospheric methanol measurement technique, employing selective gas-phase catalytic conversion of methanol to formaldehyde followed by detection of the formaldehyde product, has been developed and tested. The effects of temperature, gas flow rate, gas composition, reactor-bed length, and reactor-bed composition on the methanol conversion efficiency of a molybdenum-rich, iron-molybdate catalyst [Mo-Fe-O] were studied. Best results were achieved using a 1:4 mixture (w/w of the catalyst in quartz sand. Optimal methanol to formaldehyde conversion (>95% efficiency occurred at a catalyst housing temperature of 345°C and an estimated sample-air/catalyst contact time of <0.2 seconds. Potential interferences arising from conversion of methane and a number of common volatile organic compounds (VOC to formaldehyde were found to be negligible under most atmospheric conditions and catalyst housing temperatures. Using the new technique, atmospheric measurements of methanol were made at the University of Bremen campus from 1 to 15 July 2004. Methanol mixing ratios ranged from 1 to 5 ppb with distinct maxima at night. Formaldehyde mixing ratios, obtained in conjunction with methanol by periodically bypassing the catalytic converter, ranged from 0.2 to 1.6 ppb with maxima during midday. These results suggest that selective, catalytic methanol to formaldehyde conversion, coupled with existing formaldehyde measurement instrumentation, is an inexpensive and effective means for monitoring atmospheric methanol.

  4. Effects of air humidity on ionization chamber response

    International Nuclear Information System (INIS)

    A study of the effect of air humidity on four different ionization chamber cap materials verified earlier studies (Kristensen and Sundbom, 1981; Mijnheer et al., 1983) and extended our understanding of the problem. We found nylon and A-150 plastic caps swell as they absorb water from the air. This accounts for as much as 2.5% increase in ionization response. Graphite chambers readily absorb and desorb water from the air. This creates a problem in maintaining dry air in a wet graphite chamber. Humid air has a different density and W value than dry air (Niatel, 1969, 1975). This decreases the charge collected in a wet graphite chamber. We observe a decrease in response of approximately 2%, a value greater than can be accounted for by these effects alone. Polyethylene chambers are unaffected by humid air. 4 refs., 9 figs

  5. Kinetics of heterogeneous catalytic reactions

    CERN Document Server

    Boudart, Michel

    2014-01-01

    This book is a critical account of the principles of the kinetics of heterogeneous catalytic reactions in the light of recent developments in surface science and catalysis science. Originally published in 1984. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase acc

  6. Molecular catalytic coal liquid conversion

    Energy Technology Data Exchange (ETDEWEB)

    Stock, L.M.; Yang, Shiyong [Univ. of Chicago, IL (United States)

    1995-12-31

    This research, which is relevant to the development of new catalytic systems for the improvement of the quality of coal liquids by the addition of dihydrogen, is divided into two tasks. Task 1 centers on the activation of dihydrogen by molecular basic reagents such as hydroxide ion to convert it into a reactive adduct (OH{center_dot}H{sub 2}){sup {minus}} that can reduce organic molecules. Such species should be robust withstanding severe conditions and chemical poisons. Task 2 is focused on an entirely different approach that exploits molecular catalysts, derived from organometallic compounds that are capable of reducing monocyclic aromatic compounds under very mild conditions. Accomplishments and conclusions are discussed.

  7. Computational Introduction of Catalytic Activity into Proteins.

    Science.gov (United States)

    Bertolani, Steve J; Carlin, Dylan Alexander; Siegel, Justin B

    2016-01-01

    Recently, there have been several successful cases of introducing catalytic activity into proteins. One method that has been used successfully to achieve this is the theozyme placement and enzyme design algorithms implemented in Rosetta Molecular Modeling Suite. Here, we illustrate how to use this software to recapitulate the placement of catalytic residues and ligand into a protein using a theozyme, protein scaffold, and catalytic constraints as input. PMID:27094294

  8. Estimating the temperature of a catalytic converter

    Energy Technology Data Exchange (ETDEWEB)

    Ma, T.T.-H.

    1994-11-02

    A method is described for estimating the temperature in a catalytic converter used in the exhaust system of an internal combustion engine. Pressure sensors monitor the flow resistance across the catalytic converter to provide an indication of the temperature inside. This feedback system allows heating devices to be switched off and thus avoid overheating, while maintaining the catalytic converter's efficiency by assuring that it does not operate below its light off temperature. (UK)

  9. Estimating the temperature of a catalytic converter

    Energy Technology Data Exchange (ETDEWEB)

    Ma, T.T.-H.

    1994-11-02

    A method of estimating the temperature of a catalytic converter used in the exhaust system of an internal combustion engine is described. Heated exhaust gas oxygen (HEGO) sensors are placed upstream and downstream of the catalytic converter. The temperature of the catalytic converter shortly after start-up is measured by monitoring the resistance of the HEGO sensor's heating element. The downstream sensor is used for mixture control and to double check results of the upstream sensor. (UK)

  10. Some Aspects of the Catalytic Organic Synthesis

    Institute of Scientific and Technical Information of China (English)

    Anil; K.Saikia

    2007-01-01

    1 Results Catalytic reactions are gaining importance due to its low cost, operational simplicity, high efficiency and selectivity. It is also getting much attention in green synthesis. Many useful organic reactions, including the acylation of alcohols and aldehydes, carbon-carbon, carbon-nitrogen, carbon-sulfur bond forming and oxidation reactions are carried out by catalyst. We are exploring the catalytic acylation of alcohols and aldehydes in a simple and efficient manner. Catalytic activation of unr...

  11. Bubble Hair and Other Acquired Hair Shaft Anomalies due to Hot Ironing on Wet Hair

    OpenAIRE

    Savitha, AS; S Sacchidanand; Revathy, TN

    2011-01-01

    Bubble hair is an acquired hair shaft abnormality characterized by multiple airfilled spaces within the hair shaft. It is a result of thermal injury. We report a classic case of 22-year-old female who complained of dry brittle hair of two-week duration. Patient had used hot iron on wet hair twice to straighten hair. Hair microscopy was diagnostic and showed multiple air-filled spaces within the hair shaft.

  12. Characteristics of flow in wet conical spouted beds of unequal-sized spherical Particles

    OpenAIRE

    M. S. Bacelos; PASSOS M. L.; J. T. Freire

    2008-01-01

    Interparticle forces, developed in wet spouted beds composed of a mixture of spherical particles with different size distributions, intensify particle segregation mechanisms interfering in gas distribution inside the bed and, consequently, in the spouting flow characteristics. Therefore, this paper is aimed at describing the effect of interparticle forces on the air-solid flow distribution in conical spouted beds of unequal-sized particles coated by a thin glycerol film. Experimental results ...

  13. Investigation of sub-wet bulb temperature evaporative cooling system for cooling in buildings

    OpenAIRE

    Alharbi, Abdulrahman

    2014-01-01

    The work presented in this thesis investigates design, computer modelling and testing a sub-wet bulb temperature evaporative cooling system for space air conditioning in buildings. The context of this evaporative cooling technology design is specifically targeted at locations with a hot and dry climate such as that prevailing in most regions of Middle East countries. The focus of this technology is to address the ever-escalating energy consumption in buildings for space cooling using mechanic...

  14. Nanotemplated High-Temperature Materials for Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Elm Svensson, Erik

    2008-06-15

    Catalytic combustion is a promising technology for heat and power applications, especially gas turbines. By using catalytic combustion ultra low emissions of nitrogen oxides (NO{sub x}), carbon monoxide (CO) and unburned hydrocarbons (UHC) can be reached simultaneously, which is very difficult with conventional combustion technologies. Besides achieving low emission levels, catalytic combustion can stabilize the combustion and thereby be used to obtain stable combustion with low heating-value gases. This thesis is focused on the high-temperature part of the catalytic combustor. The level of performance demanded on this part has proven hard to achieve. In order to make the catalytic combustor an alternative to the conventional flame combustor, more stable catalysts with higher activity have to be developed. The objective of this work was to develop catalysts with higher activity and stability, suitable for the high-temperature part of a catalytic combustor fueled by natural gas. Two template-based preparation methods were developed for this purpose. One method was based on soft templates (microemulsion) and the other on hard templates (carbon). Supports known for their stability, magnesia and hexaaluminate, were prepared using the developed methods. Catalytically active materials, perovskite (LaMnO{sub 3}) and ceria (CeO{sub 2}), were added to the supports in order to obtain catalysts with high activities and stabilities. The supports were impregnated with active materials by using a conventional technique as well as by using the microemulsion technique. It was shown that the microemulsion method can be used to prepare catalysts with higher activity compared to the conventional methods. Furthermore, by using a microemulsion to apply active materials onto the support a significantly higher activity was obtained than when using the conventional impregnation technique. Since the catalysts will operate in the catalytic combustor for extended periods of time under harsh

  15. Wettability alteration by trimeric cationic surfactant at water-wet/oil-wet mica mineral surfaces

    International Nuclear Information System (INIS)

    The wettability of oil reservoir rock affects the efficiency of the oil recovery process by reducing the capillary force. Methyldodecylbis [2-(dimethyldodecylammonio) ethyl] ammonium tribromide is a trimeric cationic surfactant that contains three dodecyl chains and three quaternary ammonium head groups connected by divinyl groups. The surfactant was synthesized, purified and used as a new wetting alteration agent. This paper focuses on the ability of this trimeric cationic surfactant to alter the wettability of water-wet and oil-wet mica mineral surfaces. The contact angle data of the solid-liquid interface in oil/water/solid three-phase system show that the trimeric cationic surfactant, when compared with single- and double-chain cationic surfactant, is a more effective wetting agent for water-wet and oil-wet mica surfaces at lower concentration. Measurements by atomic force microscopy (AFM) show that the surfactant molecules have formed a monolayer to reverse the wetting properties. On the water-wet surface, the surface is suffused with negative charge, which could attract the cationic head of surfactant, and leave the hydrophobic tails exposed. In contrast, on the oil-wet surface, the hydrophobic tails were attracted by hydrophobic interactions to the oil film between the surfactant and the crude oil. The hydrophilic heads were left outside to form a hydrophilic layer, which could explain the wettable to hydrophilic trend. Alteration to the degree of wettability is mainly dependent on the adsorption areas of the surfactant. The data show that the ability of the trimeric cationic surfactant affect the wettability is independent of surface tension.

  16. Wet oxidation of a spacecraft model waste

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T.

    1985-01-01

    Wet oxidation was used to oxidize a spacecraft model waste under different oxidation conditions. The variables studied were pressure, temperature, duration of oxidation, and the use of one homogeneous and three heterogeneous catalysts. Emphasis is placed on the final oxidation state of carbon and nitrogen since these are the two major components of the spacecraft model waste and two important plant nutrients.

  17. A literature review on wet deposition

    International Nuclear Information System (INIS)

    The literature on wet deposition or precipitation scavenging have been reviewed with special reference to predicting the radiological consequences of accidental contamination. The work was part of the EEC Radiation Protection Programme and done under a subcontract with Association Euratom-C.E.A. No. SC-014-BIAF-423-DK(SD). (author)

  18. Characteristics of wetting temperature during spray cooling

    International Nuclear Information System (INIS)

    An experimental study has been done to elucidate the effects of mass flux and subcooling of liquid and thermal properties of solid on the wetting temperature during cooling of a hot block with spray. A water spray was impinged at one of the end surfaces of a cylindrical block initially heated at 400 or 500degC. The experimental condition was mass fluxes G=1-9 kg/m2 s and degrees of subcooling ΔTsub =20, 50, 80 K. Three blocks of copper, brass and carbon steel were prepared. During spray cooling internal block temperature distribution and sputtering sound pressure level were recorded and the surface temperature and heat flux were evaluated with 2D inverse heat conducting analysis. Cooling process on cooling curves is divided into four regimes categorized by change in a flow situation and the sound level. The wetting temperature defined as the wall temperature at a minimum heat flux point was measured over an extensive experimental range. The wetting wall temperature was correlated well with the parameter of GΔTsub. The wetting wall temperature increases as GΔTsub increases and reaches a constant value depending on the material of the surface at higher region of GΔTsub. (author)

  19. Verification of wet blasting decontamination technology

    International Nuclear Information System (INIS)

    Macoho Co., Ltd. participated in the projects of 'Decontamination Verification Test FY 2011 by the Ministry of the Environment' and 'Decontamination Verification Test FY 2011 by the Cabinet Office.' And we tested verification to use a wet blasting technology for decontamination of rubble and roads contaminated by the accident of Fukushima Daiichi Nuclear Power Plant of the Tokyo Electric Power Company. As a results of the verification test, the wet blasting decontamination technology showed that a decontamination rate became 60-80% for concrete paving, interlocking, dense-grated asphalt pavement when applied to the decontamination of the road. When it was applied to rubble decontamination, a decontamination rate was 50-60% for gravel and approximately 90% for concrete and wood. It was thought that Cs-134 and Cs-137 attached to the fine sludge scraped off from a decontamination object and the sludge was found to be separated from abrasives by wet cyclene classification: the activity concentration of the abrasives is 1/30 or less than the sludge. The result shows that the abrasives can be reused without problems when the wet blasting decontamination technology is used. (author)

  20. Analysis of Altimeter Wet Troposphere Range Correction

    Institute of Scientific and Technical Information of China (English)

    纪永刚; 张杰; 姬光荣; 张有广

    2004-01-01

    Wet path delay caused by tropospheric water vapor must be considered before altimeter data are used in oceanic application. This paper analyzed several methods of atmosphere water range correction (AWRC) using Seasat, Geosat, TOPEX and ERS-1 data, especially the calculated delay path using brightness temperature of TMR on TOPEX and EMR on ERS-1; and discussed some other problems of AWRC.

  1. Influence of summer and winter climate variability on nitrogen wet deposition in Norway

    Directory of Open Access Journals (Sweden)

    L. R. Hole

    2007-09-01

    Full Text Available Dominating wind patterns around Norway may change due to climate warming. This could affect transport of polluted air masses and precipitation. Here, we study relations between reactive nitrogen wet deposition and air mass transport during summer and winter expressed in the form of climate indices, at seven sites in Southern Norway for the period 1980–2005. Atmospheric nitrate concentrations decreased with 0 to 50% in the period, particularly at sites with little precipitation, and mostly during 1990–2005. For comparison, reported reductions in emissions of oxidised nitrogen in Europe in 1989–2003 were 23%. Climate indices explained up to 36% of the variation in winter nitrate deposition at the western and northern sites – and also explained 60% of the variation in winter precipitation (R=0.77. This suggests that the variation in nitrate wet deposition is closely related to variation in precipitation, and that the climate indices seem to also partly control the variation in atmospheric nitrate concentrations (R=−0.45 at coastal sites. At the coastal sites, local air temperature was highly correlated (R=0.84 with winter nitrate deposition, suggesting that warm, humid winter weather results in increased wet nitrate deposition. For ammonia the pattern was similar, but this compound is more influenced by local sources. Expected severe increase in precipitation in western and northern regions as a consequence of climate change suggest that nitrogen deposition in these areas will increase under global warming if emissions are held constant.

  2. Catalytic reforming feed characterisation technique

    Energy Technology Data Exchange (ETDEWEB)

    Larraz Mora, R.; Arvelo Alvarez, R. [Univ. of La Laguna, Chemical Engineering Dept., La Laguna (Spain)

    2002-09-01

    The catalytic reforming of naphtha is one of the major refinery processes, designed to increase the octane number of naphtha or to produce aromatics. The naphtha used as catalytic reformer feedstock usually contains a mixture of paraffins, naphthenes, and aromatics in the carbon number range C{sub 6} to C{sub 10}. The detailed chemical composition of the feed is necessary to predict the aromatics and hydrogen production as well as the operation severity. The analysis of feed naphtha is usually reported in terms of its ASTM distillation curve and API or specific gravity. Since reforming reactions are described in terms of lumped chemical species (paraffins, naphthenes and aromatics), a feed characterisation technique should be useful in order to predict reforming operating conditions and detect feed quality changes. Unfortunately online analyzer applications as cromatography or recently introduced naphtha NMR [1] are scarce in most of refineries. This work proposes an algorithmic characterisation method focusing on its main steps description. The method could help on the subjects previously described, finally a calculation example is shown. (orig.)

  3. A Capillary-Based Static Phase Separator for Highly Variable Wetting Conditions

    Science.gov (United States)

    Thomas, Evan A.; Graf, John C.; Weislogel, Mark M.

    2010-01-01

    The invention, a static phase separator (SPS), uses airflow and capillary wetting characteristics to passively separate a two-phase (liquid and air) flow. The device accommodates highly variable liquid wetting characteristics. The resultant design allows for a range of wetting properties from about 0 to over 90 advancing contact angle, with frequent complete separation of liquid from gas observed when using appropriately scaled test conditions. Additionally, the design accommodates a range of air-to-liquid flow-rate ratios from only liquid flow to over 200:1 air-to-liquid flow rate. The SPS uses a helix input section with an ice-cream-cone-shaped constant area cross section (see figure). The wedge portion of the cross section is on the outer edge of the helix, and collects the liquid via centripetal acceleration. The helix then passes into an increasing cross-sectional area vane region. The liquid in the helix wedge is directed into the top of capillary wedges in the liquid containment section. The transition from diffuser to containment section includes a 90 change in capillary pumping direction, while maintaining inertial direction. This serves to impinge the liquid into the two off-center symmetrical vanes by the airflow. Rather than the airflow serving to shear liquid away from the capillary vanes, the design allows for further penetration of the liquid into the vanes by the air shear. This is also assisted by locating the air exit ports downstream of the liquid drain port. Additionally, any droplets not contained in the capillary vanes are re-entrained downstream by a third opposing capillary vane, which directs liquid back toward the liquid drain port. Finally, the dual air exit ports serve to slow the airflow down, and to reduce the likelihood of shear. The ports are stove-piped into the cavity to form an unfriendly capillary surface for a wetting fluid to carryover. The liquid drain port is located at the start of the containment region, allowing for

  4. Epimacular brachytherapy for wet AMD: current perspectives

    Directory of Open Access Journals (Sweden)

    Casaroli-Marano RP

    2014-08-01

    Full Text Available Ricardo P Casaroli-Marano,1,2 Socorro Alforja,1 Joan Giralt,1 Michel E Farah2 1Instituto Clínic de Oftalmología (Hospital Clínic de Barcelona, University of Barcelona, Barcelona, Spain; 2Department of Ophthalmology and Visual Sciences, Universidade Federal de Sao Paulo, Escola Paulista de Medicina, Sao Paulo, Brazil Abstract: Age-related macular degeneration (AMD is considered the most common cause of blindness in the over-60 age group in developed countries. There are basically two forms of presentation: geographic (dry or atrophic and wet (neovascular or exudative. Geographic atrophy accounts for approximately 85%–90% of ophthalmic frames and leads to a progressive degeneration of the retinal pigment epithelium and the photoreceptors. Wet AMD causes the highest percentage of central vision loss secondary to disease. This neovascular form involves an angiogenic process in which newly formed choroidal vessels invade the macular area. Today, intravitreal anti-angiogenic drugs attempt to block the angiogenic events and represent a major advance in the treatment of wet AMD. Currently, combination therapy for wet AMD includes different forms of radiation delivery. Epimacular brachytherapy (EMBT seems to be a useful approach to be associated with current anti-vascular endothelial growth factor agents, presenting an acceptable efficacy and safety profile. However, at the present stage of research, the results of the clinical trials carried out to date are insufficient to justify extending routine use of EMBT for the treatment of wet AMD. Keywords: macular degeneration, radiation, vascular endothelial growth factor, combined therapy, intravitreal therapy, vitrectomy

  5. Block copolymer hollow fiber membranes with catalytic activity and pH-response

    KAUST Repository

    Hilke, Roland

    2013-08-14

    We fabricated block copolymer hollow fiber membranes with self-assembled, shell-side, uniform pore structures. The fibers in these membranes combined pores able to respond to pH and acting as chemical gates that opened above pH 4, and catalytic activity, achieved by the incorporation of gold nanoparticles. We used a dry/wet spinning process to produce the asymmetric hollow fibers and determined the conditions under which the hollow fibers were optimized to create the desired pore morphology and the necessary mechanical stability. To induce ordered micelle assembly in the doped solution, we identified an ideal solvent mixture as confirmed by small-angle X-ray scattering. We then reduced p-nitrophenol with a gold-loaded fiber to confirm the catalytic performance of the membranes. © 2013 American Chemical Society.

  6. Characterization of Catalytic Porous Medium Using Platinum for Micro-combustion Application

    Directory of Open Access Journals (Sweden)

    Miskam Muhamad Azman

    2014-07-01

    Full Text Available In this study, catalytic alumina porous medium has been fabricated by using platinum as an active material for micro-combustion application. Platinum has been deposited onto porous medium surface via wet impregnation method. The porous medium undergoes surface modification process via wash coating method using gamma alumina (γ-Al2O3 solution, before being impregnated with platinum in order to increase the surface area. The surface morphology of porous medium entirely changes from smooth “solid-rock” into rough “sand-like” after the wash coating process. The amount of platinum deposited onto the treated porous medium is 1.66 wt.%. LPG combustion analysis shows that the combustion is successfully occur inside the catalytic porous media with overall efficiency of 71%.

  7. Recycle attuned catalytic exchange (RACE) for reliable and low inventory processing of highly tritiated water

    International Nuclear Information System (INIS)

    The detritiation of highly tritiated water by liquid phase catalytic exchange needs dilution of the feed with water to tritium concentrations suitable for catalyst and safety rules and to assure flow rates large enough for wetting the catalyst. Dilution by recycling detritiated water from within the exchange process has three advantages: the amount and concentration of the water for dilution is controlled within the exchange process, there is no additional water load to processes located downstream RACE, and the ratio of gas to liquid flow rates in the exchange column could be adjusted by using several recycles differing in amount and concentration to avoid an excessively large number of theoretical separation stages. In this paper, the flexibility of the recycle attuned catalytic exchange (RACE) and its effect on the cryogenic distillation are demonstrated for the detritiation of the highly tritiated water from a tritium breeding blanket

  8. CMOS-compatible catalytic growth of graphene on a silicon dioxide substrate

    Science.gov (United States)

    Lee, Jae-Hyun; Kim, Min-Sung; Lim, Jae-Young; Jung, Su-Ho; Kang, Seog-Gyun; Shin, Hyeon-Jin; Choi, Jae-Young; Hwang, Sung-Woo; Whang, Dongmok

    2016-08-01

    We report the direct growth of graphene on a dielectric SiO2 surface by utilizing complementary metal oxide semiconductor compatible germane as a gas-phase catalyst. Results of Raman spectroscopy and XPS confirmed that the synthesized graphene consist of a sp2 hybridized carbon network. We were able to fabricate graphene field effect transistors without the wet etching process, and the calculated mobility was ˜160 cm2/V.s at high carrier concentration (n = 3 × 1012 cm-2). Furthermore, the crystallinity and morphology of graphene is easily controlled from single-layer graphene to graphene nanowall structures by adjusting the reaction conditions. The results of this study verify the promising catalytic graphene growth method on a non-catalytic insulating surface without metal contaminations.

  9. Low-temperature catalytic gasification of food processing wastes. 1995 topical report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.C.; Hart, T.R.

    1996-08-01

    The catalytic gasification system described in this report has undergone continuing development and refining work at Pacific Northwest National Laboratory (PNNL) for over 16 years. The original experiments, performed for the Gas Research Institute, were aimed at developing kinetics information for steam gasification of biomass in the presence of catalysts. From the fundamental research evolved the concept of a pressurized, catalytic gasification system for converting wet biomass feedstocks to fuel gas. Extensive batch reactor testing and limited continuous stirred-tank reactor tests provided useful design information for evaluating the preliminary economics of the process. This report is a follow-on to previous interim reports which reviewed the results of the studies conducted with batch and continuous-feed reactor systems from 1989 to 1994, including much work with food processing wastes. The discussion here provides details of experiments on food processing waste feedstock materials, exclusively, that were conducted in batch and continuous- flow reactors.

  10. Removal of ammonia from aqueous solutions by catalytic oxidation with copper-based rare earth composite metal materials: catalytic performance, characterization, and cytotoxicity evaluation

    Institute of Scientific and Technical Information of China (English)

    Chang-Mao Hung

    2011-01-01

    Ammonia (NH3) has an important use in the chemical industry and is widely found in industrial wastewater.For this investigation of copper-based rare earth composite metal materials,aqueous solutions containing 400 mg/L of ammonia were oxidized in a batch-bed reactor with a catalyst prepared by the co-precipitation of copper nitrate,lanthanum nitrate and cerium nitrate.Barely any of the dissolved ammonia was removed by wet oxidation without a catalyst,but about 88% of the ammonia was reduced during wet oxidation over the catalysts at 423 K with an oxygen partial pressure of 4.0 MPa.The catalytic redox behavior was determined by cyclic voltammetry (CV).Furthermore,the catalysts were characterized using thermogravimetric analyzer (TGA) and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX),which showed that the catalytic behavior was related to the metal oxide properties of the catalyst.In addition,the copper-lanthanum-cerium composite-induced cytotoxicity in the human lung MRC-5 cell line was tested,and the percentage cell survival was determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetra-zolium (MTS) analysis in vitro.No apparent cytotoxicity was observed when the human lung cells were exposed to the copper-lanthanum-cerium composite.

  11. Surface Structure and Catalytic Performance of Ni-Fe Catalyst for Low-Temperature CO Hydrogenation

    Directory of Open Access Journals (Sweden)

    Fanhui Meng

    2014-01-01

    Full Text Available Catalysts 16NixFe/Al2O3 (x is 0, 1, 2, 4, 6, 8 were prepared by incipient wetness impregnation method and the catalytic performance for the production of synthetic natural gas (SNG from CO hydrogenation in slurry-bed reactor were studied. The catalysts were characterized by BET, XRD, UV-Vis DRS, H2-TPR, CO-TPD, and XPS, and the results showed that the introduction of iron improved the dispersion of Ni species, weakened the interaction between Ni species and support and decreased the reduction temperature and that catalyst formed Ni-Fe alloy when the content of iron exceeded 2%. Experimental results revealed that the addition of iron to the catalyst can effectively improve the catalytic performance of low-temperature CO methanation. Catalyst 16Ni4Fe/Al2O3 with the iron content of 4% exhibited the best catalytic performance, the conversion of CO and the yield of CH4 reached 97.2% and 84.9%, respectively, and the high catalytic performance of Ni-Fe catalyst was related to the property of formed Ni-Fe alloy. Further increase of iron content led to enhancing the water gas shift reaction.

  12. Photosynthetic responses to leaf surface wetness in tropical plant species of Costa Rica with varying leaf traits

    Science.gov (United States)

    Aparecido, L. M. T.; Moore, G. W.; Miller, G. R.; Cahill, A. T.

    2015-12-01

    Wet tropical forests are some of the environments with the greatest annual precipitation, but are also considered as the world's major carbon sink; however, literature postulates that phothsynthesis rates are inhibited while leaves are wet. Yet measurements of photosynthesis during wet conditions are challenging to obtain due to equipment limitations and the extreme complexity of canopy-atmosphere interactions in tropical environments. The objective of this study was to evaluate tropical species reactions to simulated leaf wetness and test the hypothesis that leaf wetness reduces rates of photosynthesis. In a central Costa Rica site with an average 4200 mm annual rainfall, we selected six tropical species with distinct leaf traits in which five sun-exposed leaf replicates from each species were subjected to gas exchange measurements using a LI-6400 IRGA (LICOR Inc., Lincoln, NE) under dry and wet/misted leaf conditions. Relationships between photosynthesis (As) and stomatal conductance (gs) with leaf to air temperature difference (DT), VPD, and relative humidity were evaluated using linear regression analysis. We found that the responses varied greatly among species, but all plants maintained a baseline of activity under wet leaf conditions, suggesting that abaxial leaf As was a significant percentage of total leaf As. Stachytarpheta jamaicens had an 18.7% reduction in As, while others, like Zamia skinneri, had a 7% increase in As. Tibouchina heteromalla showed a rapid stomatal recovery of 2 mins, while Carapa guianensis was slower with 7 mins. This variability between species suggests that leaf traits, such as presence or absence of trichomes, water repellency, vein distribution and size and leaf angle variation, may be critical for optimizing photosynthesis under wet conditions. Relative humidity and leaf temperature were the strongest secondary influences on As and gs under wet leaf conditions. While tropical vegetation-atmosphere interactions are complex, such

  13. Gecko Adhesion on Wet and Dry Patterned Substrates.

    Science.gov (United States)

    Stark, Alyssa Y; Palecek, Amanda M; Argenbright, Clayton W; Bernard, Craig; Brennan, Anthony B; Niewiarowski, Peter H; Dhinojwala, Ali

    2015-01-01

    Perhaps one of the most astounding characteristics of the gecko adhesive system is its versatility. Geckos can locomote across complex substrates in a variety of conditions with apparent ease. In contrast, many of our synthetic pressure sensitive adhesives fail on substrates that are dirty, wet or rough. Although many studies have investigated the effect of environmental challenges on performance, the interaction of multiple, potentially compromising variables is studied less often. Here we focus on substrate structure and surface water, both of which are highly relevant to the biological system and to synthetic design. To do this we utilized a highly controlled, patterned substrate (Sharklet®, by Sharklet® Technologies Inc.). This allowed us to test independently and jointly the effects of reduced surface area substrates, with a defined pattern, on adhesion in both air and water. Our results show that adhesion is not significantly impaired in air, whereas surface area and pattern significantly affect adhesion in water. These findings highlight the need to study multiple parameters that are relevant to the gecko adhesive system to further improve our understanding of the biological system and to design better, more versatile synthetics.

  14. Gecko Adhesion on Wet and Dry Patterned Substrates.

    Directory of Open Access Journals (Sweden)

    Alyssa Y Stark

    Full Text Available Perhaps one of the most astounding characteristics of the gecko adhesive system is its versatility. Geckos can locomote across complex substrates in a variety of conditions with apparent ease. In contrast, many of our synthetic pressure sensitive adhesives fail on substrates that are dirty, wet or rough. Although many studies have investigated the effect of environmental challenges on performance, the interaction of multiple, potentially compromising variables is studied less often. Here we focus on substrate structure and surface water, both of which are highly relevant to the biological system and to synthetic design. To do this we utilized a highly controlled, patterned substrate (Sharklet®, by Sharklet® Technologies Inc.. This allowed us to test independently and jointly the effects of reduced surface area substrates, with a defined pattern, on adhesion in both air and water. Our results show that adhesion is not significantly impaired in air, whereas surface area and pattern significantly affect adhesion in water. These findings highlight the need to study multiple parameters that are relevant to the gecko adhesive system to further improve our understanding of the biological system and to design better, more versatile synthetics.

  15. Acoustics of automotive catalytic converter assemblies

    Science.gov (United States)

    Dickey, Nolan S.; Selamet, Ahmet; Parks, Steve J.; Tallio, Kevin V.; Miazgowicz, Keith D.; Radavich, Paul M.

    2003-10-01

    In an automotive exhaust system, the purpose of the catalytic converter is to reduce pollutant emissions. However, catalytic converters also affect the engine and exhaust system breathing characteristics; they increase backpressure, affect exhaust system acoustic characteristics, and contribute to exhaust manifold tuning. Thus, radiated sound models should include catalytic converters since they can affect both the source characteristics and the exhaust system acoustic behavior. A typical catalytic converter assembly employs a ceramic substrate to carry the catalytically active noble metals. The substrate has numerous parallel tubes and is mounted in a housing with swelling mat or wire mesh around its periphery. Seals at the ends of the substrate can be used to help force flow through the substrate and/or protect the mat material. Typically, catalytic converter studies only consider sound propagation in the small capillary tubes of the substrate. Investigations of the acoustic characteristics of entire catalytic converter assemblies (housing, substrate, seals, and mat) do not appear to be available. This work experimentally investigates the acoustic behavior of catalytic converter assemblies and the contributions of the separate components to sound attenuation. Experimental findings are interpreted with respect to available techniques for modeling sound propagation in ceramic substrates.

  16. Understanding catalytic biomass conversion through data mining

    NARCIS (Netherlands)

    E.J. Ras; B. McKay; G. Rothenberg

    2010-01-01

    Catalytic conversion of biomass is a key challenge that we chemists face in the twenty-first century. Worldwide, research is conducted into obtaining bulk chemicals, polymers and fuels. Our project centres on glucose valorisation via furfural derivatives using catalytic hydrogenation. We present her

  17. Silver nanocluster catalytic microreactors for water purification

    Science.gov (United States)

    Da Silva, B.; Habibi, M.; Ognier, S.; Schelcher, G.; Mostafavi-Amjad, J.; Khalesifard, H. R. M.; Tatoulian, M.; Bonn, D.

    2016-07-01

    A new method for the elaboration of a novel type of catalytic microsystem with a high specific area catalyst is developed. A silver nanocluster catalytic microreactor was elaborated by doping a soda-lime glass with a silver salt. By applying a high power laser beam to the glass, silver nanoclusters are obtained at one of the surfaces which were characterized by BET measurements and AFM. A microfluidic chip was obtained by sealing the silver coated glass with a NOA 81 microchannel. The catalytic activity of the silver nanoclusters was then tested for the efficiency of water purification by using catalytic ozonation to oxidize an organic pollutant. The silver nanoclusters were found to be very stable in the microreactor and efficiently oxidized the pollutant, in spite of the very short residence times in the microchannel. This opens the way to study catalytic reactions in microchannels without the need of introducing the catalyst as a powder or manufacturing complex packed bed microreactors.

  18. Selective catalytic oxidation of ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Leppaelahti, J.; Koljonen, T. [VTT Energy, Espoo (Finland)

    1996-12-31

    In the combustion of fossil fuels, the principal source of nitrogen oxides is nitrogen bound in the fuel structure. In gasification, a large part of fuel nitrogen forms NH{sub 3}, which may form nitrogen oxides during gas combustion. If NH{sub 3} and other nitrogen species could be removed from hot gas, the NO emission could be considerably reduced. However, relatively little attention has been paid to finding new means of removing nitrogen compounds from the hot gasification gas. The possibility of selectively oxidizing NH{sub 3} to N{sub 2} in the hot gasification has been studied at VTT Energy. The largest NH{sub 3} reductions have been achieved by catalytic oxidation on aluminium oxides. (author) (4 refs.)

  19. Reducing catalytic converter pressure loss

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    This article examines why approximately 30--40% of total exhaust-system pressure loss occurs in the catalytic converter and what can be done to reduce pressure loss. High exhaust-system backpressure is of concern in the design of power trains for passenger cars and trucks because it penalizes fuel economy and limits peak power. Pressure losses occur due to fluid shear and turning during turbulent flow in the converter headers and in entry separation and developing laminar-flow boundary layers within the substrate flow passages. Some of the loss mechanisms are coupled. For example, losses in the inlet header are influenced by the presence of the flow resistance of a downstream substrate. Conversely, the flow maldistribution and pressure loss of the substrate(s) depend on the design of the inlet header.

  20. Non-catalytic recuperative reformer

    Energy Technology Data Exchange (ETDEWEB)

    Khinkis, Mark J.; Kozlov, Aleksandr P.; Kurek, Harry

    2015-12-22

    A non-catalytic recuperative reformer has a flue gas flow path for conducting hot flue gas from a thermal process and a reforming mixture flow path for conducting a reforming mixture. At least a portion of the reforming mixture flow path is embedded in the flue gas flow path to permit heat transfer from the hot flue gas to the reforming mixture. The reforming mixture flow path contains substantially no material commonly used as a catalyst for reforming hydrocarbon fuel (e.g., nickel oxide, platinum group elements or rhenium), but instead the reforming mixture is reformed into a higher calorific fuel via reactions due to the heat transfer and residence time. In a preferred embodiment, extended surfaces of metal material such as stainless steel or metal alloy that are high in nickel content are included within at least a portion of the reforming mixture flow path.

  1. Catalytic Graphitization of Phenolic Resin

    Institute of Scientific and Technical Information of China (English)

    Mu Zhao; Huaihe Song

    2011-01-01

    The catalytic graphitization of thermal plastic phenolic-formaldehyde resin with the aid of ferric nitrate (FN) was studied in detail. The morphologies and structural features of the products including onion-like carbon nanoparticles and bamboo-shaped carbon nanotubes were investigated by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction and Raman spectroscopy measurements. It was found that with the changes of loading content of FN and residence time at 1000℃, the products exhibited various morphologies. The TEM images showed that bamboo-shaped carbon nanotube consisted of tens of bamboo sticks and onion-like carbon nanoparticle was made up of quasi-spherically concentrically closed carbon nanocages.

  2. Catalytic converter with thermoelectric generator

    Energy Technology Data Exchange (ETDEWEB)

    Parise, R.J.

    1998-07-01

    The unique design of an electrically heated catalyst (EHC) and the inclusion of an ECO valve in the exhaust of an internal combustion engine will meet the strict new emission requirements, especially at vehicle cold start, adopted by several states in this country as well as in Europe and Japan. The catalytic converter (CC) has been a most useful tool in pollution abatement for the automobile. But the emission requirements are becoming more stringent and, along with other improvements, the CC must be improved to meet these new standards. Coupled with the ECO valve, the EHC can meet these new emission limits. In an internal combustion engine vehicle (ICEV), approximately 80% of the energy consumed leaves the vehicle as waste heat: out the tail pipe, through the radiator, or convected/radiated off the engine. Included with the waste heat out the tail pipe are the products of combustion which must meet strict emission requirements. The design of a new CC is presented here. This is an automobile CC that has the capability of producing electrical power and reducing the quantity of emissions at vehicle cold start, the Thermoelectric Catalytic Power Generator. The CC utilizes the energy of the exothermic reactions that take place in the catalysis substrate to produce electrical energy with a thermoelectric generator. On vehicle cold start, the thermoelectric generator is used as a heat pump to heat the catalyst substrate to reduce the time to catalyst light-off. Thus an electrically heated catalyst (EHC) will be used to augment the abatement of tail pipe emissions. Included with the EHC in the exhaust stream of the automobile is the ECO valve. This valve restricts the flow of pollutants out the tail pipe of the vehicle for a specified amount of time until the EHC comes up to operating temperature. Then the ECO valve opens and allows the full exhaust, now treated by the EHC, to leave the vehicle.

  3. Effect of dry and wet ambient environment on the pulsed laser ablation of titanium

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Nisar, E-mail: chnisarali@gmail.com [Centre for Advanced Studies in Physics, GC University Lahore (Pakistan); Bashir, Shazia; Umm-i-Kalsoom,; Akram, Mahreen; Mahmood, Khaliq [Centre for Advanced Studies in Physics, GC University Lahore (Pakistan)

    2013-04-01

    Surface and structural properties of the laser irradiated titanium targets have been investigated under dry and wet ambient environments. For this purpose KrF Excimer laser of wavelength 248 nm, pulse duration of 20 ns and repetition rate of 20 Hz has been employed. The targets were exposed for various number of laser pulses ranging from 500 to 2000 in the ambient environment of air, de-ionized water and propanol at a fluence of 3.6 J/cm{sup 2}. The surface morphology, chemical composition and crystallographical analysis were performed by using Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD), respectively. For both central and peripheral ablated areas, significant difference in surface morphology has been observed in case of dry and wet ambient conditions. Large sized and diffused grains are observed in case of dry ablation. Whereas, in case of wet ablation, small sized, and well defined grains with distinct grain boundaries and significantly enhanced density are revealed. This difference is ascribed to the confinement effects of the liquid. The peripheral ablated area shows redeposition in case of dry ablation whereas small sized grain like structures are formed in case of wet ablation. EDS analysis exhibits variation in chemical composition under both ambient conditions. When the targets are treated in air environment, enhancement of the oxygen as well as nitrogen content is observed while in case of de-ionized water and propanol only increase in content of oxygen is observed. X-ray diffraction analysis exhibits formation of oxides and nitrides in case of air, whereas, in case of de-ionized water and propanol only oxides along with hydrides are formed. For various number of laser pulses the variation in the peak intensity, crystallinity and d-spacing is observed under both ambient conditions.

  4. The composition of wet deposition in El Paso, Texas

    Science.gov (United States)

    Emmert, Sonny

    The composition of precipitation reflects the transport of particles from varying air mass source regions as well as input from local environmental and anthropogenic activities. Air research in El Paso, TX, U.S.A/Ciudad Juarez, Chihuahua, Mexico has been traditionally limited to studies of local inputs of air pollution; no transition has been made to studying the scavenging, washout, and transport of pollutants by precipitation. The goal of this research project was to identify transported pollutants in precipitation, and determine if there were any health and ecological implications. The research investigated biological, chemical, and geological constituents in precipitation samples collected between September 2004 and October 2005. A variety of analysis techniques were used to determine composition of the precipitation. These techniques included bacterial and fungal plate counts, inductively coupled plasma/mass spectrometry, ion chromatography, transmission electron microscopy, scanning electron microscopy, and electron microprobe analysis. Samples were collected from an urban site in El Paso, Texas at the campus of the University of Texas at El Paso. Wet only samples were the target of the sample collection. Particulate matter <10 microns was correlated with fungal growth while particulate matter < 2.5 microns was correlated with bacterial growth in analyzed samples. Microscopy methods revealed new techniques in particle characterization, evidence of anthropogenic influence, and a wide variety of particle compositions. The ionic chemistry results reflected elevated levels of ions as well as an overall alkalinity of rainwater samples. Elemental analysis of the inorganic fraction suggested elevated enrichment of Phosphorus in the study area and possible ratios for transport identification of southwestern dust storms.

  5. Effects of wetness in steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Hesketh, J.A.; Walker, P.J. [Alstom Power, Rugby (United Kingdom). Power Turbo Systems Sector

    2005-12-15

    Courses in mechanical engineering usually introduce the theory of axial-flow turbo-machines in terms of simple velocity triangles representing the bulk flow of ideal compressible fluid through the blade passages. A distinctive practical difference, peculiar to steam turbines (ST), is the presence of liquid-water in the flow field. The steam wetness in such turbines is widely known to be doubly-damaging, leading to both loss of efficiency and to mechanical damage (erosion, etc.) of the machine components. Over recent decades, a whole new field of mechanical engineering science has evolved on the subject of wetness in steam turbines, and general practices have been established within the industry. This article reviews the general effects that are of major importance to the turbine designer/engineer, power plant operator, and especially to researchers in this field. (author)

  6. Liquid holdup in wet-gas pipelines

    International Nuclear Information System (INIS)

    An experimental study of two-phase flow was conducted to investigate liquid holdup in wet-gas pipelines. The liquid-holdup data were obtained by passing spheres through a 1,333-ft [406.3-m] -long, 3.068-in. [77.93-mm] -ID horizontal pipe and measuring the liquid volumes removed. Three different two-phase mixtures were used. The holdup data were compared with predicted holdup values and were used to evaluate a mechanistic model for stratified flow. None of the methods could accuratly predict liquid holdup in this low-holdup region. Two new empirical liquid-holdup correlations for horizontal flow were proposed. The first is strictly for wet-gas pipelines (0< y/sub L/<0.35); the second is for any horizontal pipeline (0< y/sub L/<1.0)

  7. Wet electron microscopy with quantum dots.

    Science.gov (United States)

    Timp, Winston; Watson, Nicki; Sabban, Alon; Zik, Ory; Matsudaira, Paul

    2006-09-01

    Wet electron microscopy (EM) is a new imaging method with the potential to allow higher spatial resolution of samples. In contrast to most EM methods, it requires little time to perform and does not require complicated equipment or difficult steps. We used this method on a common murine macrophage cell line, IC-21, in combination with various stains and preparations, to collect high resolution images of the actin cytoskeleton. Most importantly, we demonstrated the use of quantum dots in conjunction with this technique to perform light/electron correlation microscopy. We found that wet EM is a useful tool that fits into a niche between the simplicity of light microscopy and the high spatial resolution of EM.

  8. A novel method for "Wet" SEM.

    Science.gov (United States)

    Barshack, Iris; Kopolovic, Juri; Chowers, Yehuda; Gileadi, Opher; Vainshtein, Anya; Zik, Ory; Behar, Vered

    2004-01-01

    Progress in the processing of wet tissues, without the need of fixation and complex preparation procedures, may facilitate the microscopic examination of tissues and cells. Microscopic examination of tissues is a central tool in clinical diagnosis as well as in diverse areas of research. The authors present the application of Wet SEM, a technology for imaging fully hydrated samples at atmospheric pressure in a scanning electron microscope (SEM). The technique is based on 2 principles. First, samples are imaged in sealed specimen capsules and are separated from the evacuated interior of the electron microscope by a thin, electron-transparent partition membrane that is strong enough to sustain a 1-atm pressure difference. Second, imaging is done in a SEM, based on detection of backscattered electrons, which penetrate a few microns into the specimen and thus give information on the cellular level.

  9. Experimental Investigation of Wetting with Magnetic Fluids.

    Science.gov (United States)

    Manukyan, Selin; Schneider, Marius

    2016-05-24

    Here we report the experimental results of the general wetting behavior of an oil-based ferrofluid and a water-based magnetic paint droplet on a hydrophobic surface under the effect of an external magnetic field. By increasing the magnetic field in the vertical direction, the height of the oil-based ferrofluid droplet increases while the width decreases; on the contrary, under the same circumstances, the height of the water-based magnetic paint droplet decreases whereas the width increases. The wetting behavior of the oil-based ferrofluid and the water-based magnetic paint droplets is evaluated as a function of the contact angle, contact line diameter, and hysteresis curve alterations. Conclusively, a general explanation is given for the contrary behavior of both liquids, and some application processes for future implementations are introduced. PMID:27119597

  10. Economic and technical assessment of the desiccant wheel effect on the thermal performance of cross flow cooling towers in variable wet bulb temperature

    Science.gov (United States)

    Banooni, Salem; Chitsazan, Ali

    2014-05-01

    Performance improvements of cross flow cooling towers in variable wet bulb temperature were performed. A conventional mathematical model is used to predict desiccant wheel effect on the performance of cooling tower. It is found that by using optimum parameters of desiccant wheel, the inlet air wet bulb temperature into the cooling tower would decrease more than 6 °C and outlet water temperature would decrease more than 4 °C.

  11. STUDY ON WET STRENGTH PERFORMANCE OF KENAF MULCH

    Institute of Scientific and Technical Information of China (English)

    Jinghui Zhou; Xinge Wu; Hongwei Zhu

    2004-01-01

    Optimum applied technical conditions of wet strength agent for kenaf mulch were studied in this article. Breaking length, wet-dry strength ratio, tear index and burst index of kenaf mulch were measured and optimum wet strength agent was selected. The aim is to make mulch have properties of heat preservation, humidity preservation, growth prompting, biodegradation and maximum wet strength and to improve impact resistance of mulch to rainwater so as to assure growth of plant and replace plastic film.

  12. Estimating wetting front coordinates under surface trickle irrigation

    OpenAIRE

    MOLAVI, Ahad; SADRADDINI, Aliashraf; NAZEMI, Amir Hossein; FARD, Ahmad Fakheri

    2012-01-01

    In this study, wetting front or wetted bulb coordinates in soil under surface trickle irrigation were measured for 1 loam soil and 2 sandy loam soils with 2 different emitter discharges of 2 and 4 L h-1 by using the trenching method. A model is presented for estimating wetted bulb coordinates with a function of emitter discharge, water application time, average variation in volumetric water content, and saturated hydraulic conductivity of soil. For calculating the distance of the maximum wet ...

  13. Advance of Wetting Front in Silt Loam Soil

    OpenAIRE

    Mohamed Mahmood; Haki E. Yassen

    2013-01-01

    Under drip irrigation , the plant's root is concentrated inside the wetted bulb (region). Thus, the development of these roots and the plant production are greatly affected by the wetting pattern. Therefore, the wetting pattern of soil under drip irrigation must be taken into consideration in the design of drip irrigation system for both single dripping source or multi-overlapping wetting patterns of dripping water sources.2The aim of this study is to evaluate the effect of initial water cont...

  14. Hydrogen and helium films as model systems of wetting

    OpenAIRE

    Herminghaus, Stephan; Vorberg, Jens; Gau, Hartmut; Conradt, Robert N. J.; Reinelt, Dietmar; Ulmer, Holger; Leiderer, Paul; Przyrembel, Michael

    1997-01-01

    Optical experiments on the wetting properties of liquid 4He and molecular hydrogen are reviewed. Hydrogen films on noble metal surfaces serve as model systems for studying triple point wetting, a continuous transition between wetting and non-wetting. By means of optically excited surface plasmons, the adsorbed film thickness for temperatures around, and far below, the bulk melting temperature is measured, and the physical mechanisms responsible for the transition are elucidated. Possible appl...

  15. Making Activated Carbon by Wet Pressurized Pyrolysis

    Science.gov (United States)

    Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark

    2006-01-01

    A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb

  16. Thermal Equilibrium and Wet Gas Compressor Performance

    OpenAIRE

    Aalvik, Marthe

    2011-01-01

    The wet gas performance model established for this master s thesis is based on results achieved from a single stage, low pressure ratio, centrifugal compressor set up at NTNU. Water droplets are injected to the flow right before the inlet. The GMF varies from 0.9 to 0.65 throughout the experiments preformed. Compressor performance is achieved by simulations in HYSYS with atmospheric inlet conditions. The importance of accurate measurements is evident to achieve the correct performance. A lite...

  17. Wet flue gas desulphurization and new fuels

    Energy Technology Data Exchange (ETDEWEB)

    Kiil, S.; Dam-Johansen, K.; Michelsen, M.L.

    1998-04-01

    This thesis describes experimental and theoretical investigations of wet flue gas desulphurization (FGD). A review of the current knowledge of the various rate determining steps in wet FDG plants is presented. The mechanism underlying the rate of dissolution of finely grained limestone particles was examined in a laboratory batch apparatus using acid titration. Three Danish limestones of different origin were tested. A transient, mass transport controlled, mathematical model was developed to describe the dissolution process. Model predictions were found to be qualitatively in good agreement with experimental data. Empirical correlations for the dimensionless mass transfer coefficients in a pilot plant (falling-film column) were determined. The presence of inert particles in the liquid phase was found to decrease the rate of gas phase mass transport with up to 15%, though the effect could not be correlated. A detailed model for a wet FGD pilot plant, based on the falling film principle, was developed. All important rate determining steps, absorption of SO{sub 2}, oxidation of HSO{sub 3}{sup -}, dissolution of limestone, and crystallisation of gypsum were included. Model predictions were compared to experimental data such as gas phase concentration profiles of SO{sub 2}, slurry pH-profiles, solids contents of slurry, liquid phase concentrations, and residual limestone in the gypsum. The possibility of co-firing straw and coal was investigated in a full-scale power plant. No effects on the overall performance of the wet FGD plant were observed, though laboratory experiments with fine dust and fly ash from the full-scale experiments showed a decrease in limestone reactivity. (EG) EFP-95. 45 refs.; Also ph.d. thesis of Soeren Kiil

  18. Dynamics of complete wetting liquid under evaporation

    Science.gov (United States)

    Pham, Chi-Tuong; Berteloot, Guillaume; Lequeux, FranC.{C.}Ois; Limat, Laurent

    2009-11-01

    We study the dynamics of a contact line under evaporation and complete wetting conditions taking into account the divergent nature of evaporation near the border of the liquid, as evidenced by Deegan et al. [Nature 389, 827]. The model we propose shows the existence of a precursor film at the edge of the liquid. The length of the precursor film is controlled by Hamacker constant and evaporative flux. Past the precursor film, Tanner's law is generalized accounting for evaporative effects.

  19. Study of polycaprolactone wet electrospinning process

    OpenAIRE

    E. Kostakova; M. Seps; P. Pokorny; Lukas, D.

    2014-01-01

    Wet electrospinning is a useful method for 3-dimensional structure control of nanofibrous materials. This innovative technology uses a liquid collector instead of the metal one commonly used for standard electrospinning. The article compares the internal structural features of polycaprolactone (PCL) nanofibrous materials prepared by both technologies. We analyze the influence of different water/ethanol compositions used as a liquid collector on the morphology of the resultant polycaprolactone...

  20. Static wetting behaviour of diblock copolymers

    OpenAIRE

    Ausserre, D.; Raghunathan, V.; Maaloum, M.

    1993-01-01

    Thin liquid films of ordered diblock copolymers deposited on a solid substrate form a multilayer stacking parallel to the solid surface. A multilayer with a finite extend can be stable, metastable, or unstable, depending on the relative values of the surface energies of the various interfaces. The spreading parameter and chemical potential of a n-layer are derived, and used for classifying all possible situations. It is shown that only mono- and bilayers can be stable, and that non-wetting mu...

  1. The role of thin films in wetting

    OpenAIRE

    Marmur, Abraham

    1988-01-01

    The role of thin films in wetting is reviewed. Three modes of spontaneous spreading are discussed : incomplete spreading, complete spreading and mixed-mode spreading. A thin film can be either molecular or colloidal in thickness. Molecularly adsorbed films are mainly associated with incomplete spreading. Colloidal films usually extend from the bulk of the liquid in dynamic situations of complete spreading. Their existence at equilibriuim with the bulk depends on the orientation in the gravita...

  2. Revolutionary systems for catalytic combustion and diesel catalytic particulate traps.

    Energy Technology Data Exchange (ETDEWEB)

    Stuecker, John Nicholas; Witze, Peter O.; Ferrizz, Robert Matthew; Cesarano, Joseph, III; Miller, James Edward

    2004-12-01

    This report is a summary of an LDRD project completed for the development of materials and structures conducive to advancing the state of the art for catalyst supports and diesel particulate traps. An ancillary development for bio-medical bone scaffolding was also realized. Traditionally, a low-pressure drop catalyst support, such as a ceramic honeycomb monolith, is used for catalytic reactions that require high flow rates of gases at high-temperatures. A drawback to the traditional honeycomb monoliths under these operating conditions is poor mass transfer to the catalyst surface in the straight-through channels. ''Robocasting'' is a unique process developed at Sandia National Laboratories that can be used to manufacture ceramic monoliths with alternative 3-dimensional geometries, providing tortuous pathways to increase mass transfer while maintaining low-pressure drops. These alternative 3-dimensional geometries may also provide a foundation for the development of self-regenerating supports capable of trapping and combusting soot particles from a diesel engine exhaust stream. This report describes the structures developed and characterizes the improved catalytic performance that can result. The results show that, relative to honeycomb monolith supports, considerable improvement in mass transfer efficiency is observed for robocast samples synthesized using an FCC-like geometry of alternating rods. Also, there is clearly a trade-off between enhanced mass transfer and increased pressure drop, which can be optimized depending on the particular demands of a given application. Practical applications include the combustion of natural gas for power generation, production of syngas, and hydrogen reforming reactions. The robocast lattice structures also show practicality for diesel particulate trapping. Preliminary results for trapping efficiency are reported as well as the development of electrically resistive lattices that can regenerate the structure

  3. Study of polycaprolactone wet electrospinning process

    Directory of Open Access Journals (Sweden)

    E. Kostakova

    2014-08-01

    Full Text Available Wet electrospinning is a useful method for 3-dimensional structure control of nanofibrous materials. This innovative technology uses a liquid collector instead of the metal one commonly used for standard electrospinning. The article compares the internal structural features of polycaprolactone (PCL nanofibrous materials prepared by both technologies. We analyze the influence of different water/ethanol compositions used as a liquid collector on the morphology of the resultant polycaprolactone nanofibrous materials. Scanning electron micro-photographs have revealed a bimodal structure in the wet electrospun materials composed of micro and nanofibers uniformly distributed across the sample bulk. We have shown that the full-faced, twofold fiber distribution is due to the solvent composition and is induced and enhanced by increasing the ethanol weight ratio. Moreover, the comparison of fibrous layers morphology obtained by wet and dry spinning have revealed that beads that frequently appeared in dry spun materials are created by Plateau-Rayleigh instability of the fraction of thicker fibers. Theoretical conditions for spontaneous and complete immersion of cylindrical fibers into a liquid collector are also derived here.

  4. Wetting and cavitation pathways on nanodecorated surfaces.

    Science.gov (United States)

    Amabili, Matteo; Lisi, Emanuele; Giacomello, Alberto; Casciola, Carlo Massimo

    2016-03-28

    In this contribution we study the wetting and nucleation of vapor bubbles on nanodecorated surfaces via free energy molecular dynamics simulations. The results shed light on the stability of superhydrophobicity in submerged surfaces with nanoscale corrugations. The re-entrant geometry of the cavities under investigation is capable of sustaining a confined vapor phase within the surface roughness (Cassie state) both for hydrophobic and hydrophilic combinations of liquid and solid. The atomistic system is of nanometric size; on this scale thermally activated events can play an important role ultimately determining the lifetime of the Cassie state. Such a superhydrophobic state can break down by full wetting of the texture at large pressures (Cassie-Wenzel transition) or by nucleating a vapor bubble at negative pressures (cavitation). Specialized rare event techniques show that several pathways for wetting and cavitation are possible, due to the complex surface geometry. The related free energy barriers are of the order of 100kBT and vary with pressure. The atomistic results are found to be in semi-quantitative accord with macroscopic capillarity theory. However, the latter is not capable of capturing the density fluctuations, which determine the destabilization of the confined liquid phase at negative pressures (liquid spinodal). PMID:26905783

  5. Design Aspects of Wet Scrubber System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun-Chul; Bang, Young-suk; Jung, Woo-Young; Lee, Doo-Yong [FNC Technology Co. Ltd., Yongin (Korea, Republic of)

    2015-10-15

    The water pool in the wet scrubber system has advantage to cope with decay heat based on the thermal hydraulic balance such as condensation and evaporation inside it. This study focuses on the design aspects of the wet scrubber system to estimate the required water pool mass during the mission time and size of the scrubbing tank including inner structures. The design of the wet scrubber system include the estimation of the required water mass during the mission time and sizing of the scrubber vessel to contain the water pool. The condensation due to the inlet steam and evaporation due to the steam and non-condensable gas superheat and decay heat from filtered fission products should be considered to estimate the water mass required to maintain its function during the mission time. On the other hand, the level swelling due to the noncondensable gas is another important design aspect on the sizing of the scrubber vessel and determination of the entry elevation of the filtration components such as the droplet separator or filter. The minimum water level based on the minimum collapsed water level should be higher than the exit of scrubber nozzle.

  6. Estimating soil wetness using satellite data

    Science.gov (United States)

    Choudhury, Bhaskar J.; Golus, Robert E.

    1988-01-01

    Improved estimates of soil wetness were obtained using observations from both the NIMBUS-7 Scanning Multichannel Microwave Radiometer (SMMR) and the NOAA-7 Advanced Very High Resolution Radiometer (AVHRR). SMMR 66 GHz frequency, horizontal polarization, brightness temperature T(BH) was first correlated with soil wetness, as computed using an Antecedent Precipitation Index (API) model, for a number of SMMR ground resolution areas involving a fairly wide range of vegetation densities. The API generally accounted for more than 70 percent of the observed temporal variability in T(BH), with linear correlations being significant at the 1 percent level. The regression slope of T(BH) versus API correlated well, at the 1 percent level, with a vegetation index derived from AVHRR visible and near-infrared observations. The regression intercept was found to correlate less satisfactorily, but was significant at the 5 percent level. These linear regression results were used to develop a diagnostic model for soil wetness using SMMR and AVHRR data only.

  7. Characteristics of wet work in the cleaning industry

    NARCIS (Netherlands)

    Jungbauer, F H W; Van Der Harst, J J; Schuttelaar, M L; Groothoff, J W; Coenraads, P J

    2004-01-01

    Wet work is the main cause of occupational contact dermatitis in the cleaning industry. Dermatologists and occupational physicians need to base their primary and secondary prevention for workers in the cleaning industry on the characteristics of wet work exposures. We quantified the burden of wet wo

  8. Electrochemistry of Layered Graphitic Carbon Nitride Synthesised from Various Precursors: Searching for Catalytic Effects.

    Science.gov (United States)

    Yew, Ying Teng; Lim, Chee Shan; Eng, Alex Yong Sheng; Oh, Junghoon; Park, Sungjin; Pumera, Martin

    2016-02-16

    Graphitic carbon nitride (g-C3 N4 ), synthesised by pyrolysis of different precursors (dicyandiamide, melamine and urea) under varying reaction conditions (air and nitrogen gas) is subjected to electrochemical studies for the elucidation of the inherent catalytic efficiency of the pristine material. Contrary to popular belief, pristine g-C3 N4 shows negligible, if any, enhancement in its electrochemical behaviour in this comprehensive study. Voltammetric analysis reveals g-C3 N4 to display similar catalytic efficiency to the unmodified glassy carbon electrode surface on which the bulk material was deposited. This highlights the non-catalytic nature of the pristine material and challenges the feasibility of using g-C3 N4 as a heterogeneous catalyst to deliver numerous promised applications.

  9. Investigation of Precipitation Variations over Wet and Dry Areas from Observation and Model

    Directory of Open Access Journals (Sweden)

    James H. Trammell

    2015-01-01

    Full Text Available Our observational study revealed that the precipitation increased over the wet area and decreased over the dry area during the past two decades. Here, we further investigate whether the current atmospheric models can quantitatively capture the characteristics of precipitation from the observation. The NASA Goddard Institute for Space Studies (GISS model is used to examine the historic simulation of the precipitation, in which the historic greenhouse gases and aerosols are included in the radiative forcing. The consistency between the historic GISS simulation and the Global Precipitation Climatology Project (GPCP precipitation suggests that the model can qualitatively capture the temporal trends of precipitation over the wet and dry areas. However, the precipitation trends are weaker in the model than in the observation. The observed trends of precipitation do not appear in the control simulation with the fixed concentrations of greenhouse gases and aerosols, which suggests that the global warming due to anthropogenic forcing can influence the temporal variations of precipitation over the wet and dry areas. Diagnostic studies of other variables from the model further suggest that enhanced rising air can increase the precipitation over the wet area.

  10. Aerosol chemistry during the wet season in central Amazonia - The influence of long-range transport

    Science.gov (United States)

    Talbot, R. W.; Andreae, M. O.; Berresheim, H.; Artaxo, P.; Garstang, M.

    1990-01-01

    The temporal variation in the concentration and chemistry of the atmospheric aerosol over central Amazonia, Brazil, during the 1987 wet season is discussed based on ground and aircraft collected data obtained during the NASA GTE ABLE 2B expedition conducted in April/May 1987. It is found that wet-season aerosol concentrations and composition are variable in contrast to the more uniform biogenic aerosol observed during the 1985 dry season; four distinct intervals of enhanced aerosol concentration coincided with short periods (3 to 5 d) of extensive rainfall. It is hypothesized that aerosol chemistry in Amazonia during the wet season is strongly influenced by long-range transport of soil dust, marine aerosol, and possibly biomass combustion products advected into the central Basin by large-scale tropospheric circulation, producing periodic pulses of material input to local boundary layer air. The resultant wet-season aerosol regime is dynamic, in contrast to the uniformity of natural biogenic aerosols during the dry season.

  11. Liquid spreading under partial wetting conditions

    Science.gov (United States)

    Chen, M.; Pahlavan, A. A.; Cueto-Felgueroso, L.; McKinley, G. H.; Juanes, R.

    2013-12-01

    Traditional mathematical descriptions of multiphase flow in porous media rely on a multiphase extension of Darcy's law, and lead to nonlinear second-order (advection-diffusion) partial differential equations for fluid saturations. Here, we study horizontal redistribution of immiscible fluids. The traditional Darcy-flow model predicts that the spreading of a finite amount of liquid in a horizontal porous medium never stops; a prediction that is not substantiated by observation. To help guide the development of new models of multiphase flow in porous media [1], we draw an analogy with the flow of thin films. The flow of thin films over flat surfaces has been the subject of much theoretical, experimental and computational research [2]. Under the lubrication approximation, the classical mathematical model for these flows takes the form of a nonlinear fourth-order PDE, where the fourth-order term models the effect of surface tension [3]. This classical model, however, effectively assumes that the film is perfectly wetting to the substrate and, therefore, does not capture the partial wetting regime. Partial wetting is responsible for stopping the spread of a liquid puddle. Here, we present experiments of (large-volume) liquid spreading over a flat horizontal substrate in the partial wetting regime, and characterize the four spreading regimes that we observe. We extend our previous theoretical work of two-phase flow in a capillary tube [4], and develop a macroscopic phase-field modeling of thin-film flows with partial wetting. Our model naturally accounts for the dynamic contact angle at the contact line, and therefore permits modeling thin-film flows without invoking a precursor film, leading to compactly-supported solutions that reproduce the spreading dynamics and the static equilibrium configuration observed in the experiments. We anticipate that this modeling approach will provide a natural mathematical framework to describe spreading and redistribution of immiscible

  12. Development of Catalytic Cooking Plates

    Energy Technology Data Exchange (ETDEWEB)

    Hjelm, Anna-Karin; Silversand, Fredrik [CATATOR AB, Lund (Sweden); Tena, Emmanuel; Berger, Marc [Gaz de France (France)

    2004-04-01

    Gas catalytic combustion for gas stoves or cooking plates (closed catalytic burner system with ceramic plates) is a very promising technique in terms of ease of cleaning, power modulation and emissions. Previous investigations show that wire mesh catalysts, prepared and supplied by Catator AB (CAT), seem to be very well suited for such applications. Beside significantly reducing the NOx-emissions, these catalysts offer important advantages such as good design flexibility, low pressure drop and high heat transfer capacity, where the latter leads to a quick thermal response. Prior to this project, Gaz de France (GdF) made a series of measurements with CAT's wire mesh catalysts in their gas cooking plates and compared the measured performance with similar results obtained with theirs cordierite monolith catalysts. Compared to the monolith catalyst, the wire mesh catalyst was found to enable very promising results with respect to both emission levels (<10 mg NO{sub x} /kWh, <5 mg CO/kWh) and life-time (>8000 h vs. 700 h at 200 kW/m{sup 2}). It was however established that the radiation and hence, the thermal efficiency of the cooking plate, was significantly less than is usually measured in combination with the monolith (15 % vs. 32 %). It was believed that the latter could be improved by developing new burner designs based on CAT's wire mesh concept. As a consequence, a collaboration project between GdF, CAT and the Swedish Gas Technology AB was created. This study reports on the design, the construction and the evaluation of new catalytic burners, based on CAT's wire mesh catalysts, used for the combustion of natural gas in gas cooking stoves. The evaluation of the burners was performed with respect to key factors such as thermal efficiency, emission quality and pressure drop, etc, by the use of theoretical simulations and experimental tests. Impacts of parameters such as the the wire mesh number, the wire mesh structure (planar or folded), the

  13. Catalytic reaction in confined flow channel

    Energy Technology Data Exchange (ETDEWEB)

    Van Hassel, Bart A.

    2016-03-29

    A chemical reactor comprises a flow channel, a source, and a destination. The flow channel is configured to house at least one catalytic reaction converting at least a portion of a first nanofluid entering the channel into a second nanofluid exiting the channel. The flow channel includes at least one turbulating flow channel element disposed axially along at least a portion of the flow channel. A plurality of catalytic nanoparticles is dispersed in the first nanofluid and configured to catalytically react the at least one first chemical reactant into the at least one second chemical reaction product in the flow channel.

  14. Controlling Factors of Long-Term Trends in Mercury Wet Deposition and Precipitation Concentrations at Huntington Wildlife Forest

    Science.gov (United States)

    Ye, Z.; Mao, H.; Driscoll, C. T.

    2015-12-01

    Observations from the Mercury Deposition Network (MDN) at Huntington Wildlife Forest (HWF) suggested that a significant decline (r2 = 0.34, p = 0.03) from 2000 to 2013 in volume weighted mean (VWM) Hg concentrations in precipitation was linked to Hg emission decreases in the United States, especially in the Northeast and Midwest, and yet Hg wet deposition has remained fairly constant over the past two decades. The present study aimed to investigate the climatic, terrestrial, and anthropogenic factors that influenced the decadal pattern in Hg wet deposition in upstate NY. In spring and summer, when Hg wet deposition was the strongest, significant positive correlation (r2 = 0.89, p < 0.0001 in spring; r2 = 0.58, p = 0.002 in summer) of Hg wet deposition with precipitation was found. Increases in precipitation during these seasons could offset the decreasing of Hg concentration in precipitation. Besides, springtime positive correlation (r2 = 0.35, p = 0.02) between precipitation and the North Atlantic Oscillation (NAO) index together with geopotential height and wind speed analysis indicated that large-scale dynamical forcing was likely an important factor influencing the long term trend in springtime Hg wet deposition at HWF. To further quantify the roles of meteorological and anthropogenic factors in Hg wet deposition, the Community Multiscale Air Quality (CMAQ) model was employed using an algorithm depicting state-of-the-art Hg chemistry mechanism and up-to-date Hg emission inventories evaluated with MDN and Atmospheric Mercury Network (AMNet) measurement data. CMAQ simulations with a constant vs. realistic meteorological conditions for multiple warm seasons (including spring and summer) were used to characterize and quantify the impacts of inter-annual variability of precipitation and atmospheric circulation on Hg wet deposition. In addition, contributions to Hg wet deposition from decreases in anthropogenic emissions in NYS and nation-wide were quantified from

  15. Wetness measurements in a model multistage low pressure steam turbine

    International Nuclear Information System (INIS)

    Comprehensive measurement of wetness losses, exhaust fog droplet diameters, wetness and coarse water content have been taken in a model multistage LP steam turbine over a wide range of flow conditions. It was found that for conventional condensing turbine exhaust wetness fractions of approximately 0.10, the measured wetness loss factor was in reasonable agreement with the Baumann value. Comparison of exhaust wetness fractions derived from dynamometer power and five-hole probe radial traverse measurements, with those found independently from the Central Electricity Research Laboratories optical probe traverses, generally showed agreement to within approximately ±0.01. (author)

  16. Pilot-scale field study for ammonia removal from lagoon biogas using an acid wet scrubber.

    Science.gov (United States)

    Lin, Hongjian; Wu, Xiao; Miller, Curtis; Zhu, Jun; Hadlocon, Lara Jane; Manuzon, Roderick; Zhao, Lingying

    2014-01-01

    The anaerobic activities in swine slurry storage and treatment generate biogas containing gaseous ammonia component which is a chemical agent that can cause adverse environmental impacts when released to the atmosphere. The aim of this pilot plant study was to remove ammonia from biogas generated in a covered lagoon, using a sulfuric acid wet scrubber. The data showed that, on average, the biogas contained 43.7 ppm of ammonia and its concentration was found to be exponentially related to the air temperature inside the lagoon. When the air temperature rose to 35°C and the biogas ammonia concentration reached 90 ppm, the mass transfer of ammonia/ammonium from the deeper liquid body to the interface between the air and liquid became a limiting factor. The biogas velocity was critical in affecting ammonia removal efficiency of the wet scrubber. A biogas flow velocity of 8 to 12 mm s(-1) was recommended to achieve a removal efficiency of greater than 60%. Stepwise regression revealed that the biogas velocity and air temperature, not the inlet ammonia concentration in biogas, affected the ammonia removal efficiency. Overall, when 73 g L(-1) (or 0.75 M) sulfuric acid solution was used as the scrubber solution, removal efficiencies varied from 0% to 100% with an average of 55% over a 40-d measurement period. Mass balance calculation based on ammonium-nitrogen concentration in final scrubber liquid showed that about 21.3 g of ammonia was collected from a total volume of 1169 m(3) of biogas, while the scrubber solution should still maintain its ammonia absorbing ability until its concentration reaches up to 1 M. These results showed promising use of sulfuric acid wet scrubber for ammonia removal in the digester biogas.

  17. Vacuum-insulated catalytic converter

    Energy Technology Data Exchange (ETDEWEB)

    Benson, David K. (Golden, CO)

    2001-01-01

    A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

  18. Catalytic Chemistry on Oxide Nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Asthagiri, Aravind; Dixon, David A.; Dohnalek, Zdenek; Kay, Bruce D.; Rodriquez, Jose A.; Rousseau, Roger J.; Stacchiola, Dario; Weaver, Jason F.

    2016-05-29

    Metal oxides represent one of the most important and widely employed materials in catalysis. Extreme variability of their chemistry provides a unique opportunity to tune their properties and to utilize them for the design of highly active and selective catalysts. For bulk oxides, this can be achieved by varying their stoichiometry, phase, exposed surface facets, defect, dopant densities and numerous other ways. Further, distinct properties from those of bulk oxides can be attained by restricting the oxide dimensionality and preparing them in the form of ultrathin films and nanoclusters as discussed throughout this book. In this chapter we focus on demonstrating such unique catalytic properties brought by the oxide nanoscaling. In the highlighted studies planar models are carefully designed to achieve minimal dispersion of structural motifs and to attain detailed mechanistic understanding of targeted chemical transformations. Detailed level of morphological and structural characterization necessary to achieve this goal is accomplished by employing both high-resolution imaging via scanning probe methods and ensemble-averaged surface sensitive spectroscopic methods. Three prototypical examples illustrating different properties of nanoscaled oxides in different classes of reactions are selected.

  19. Halogen Chemistry on Catalytic Surfaces.

    Science.gov (United States)

    Moser, Maximilian; Pérez-Ramírez, Javier

    2016-01-01

    Halogens are key building blocks for the manufacture of high-value products such as chemicals, plastics, and pharmaceuticals. The catalytic oxidation of HCl and HBr is an attractive route to recover chlorine and bromine in order to ensure the sustainability of the production processes. Very few materials withstand the high corrosiveness and the strong exothermicity of the reactions and among them RuO2 and CeO2-based catalysts have been successfully applied in HCl oxidation. The search for efficient systems for HBr oxidation was initiated by extrapolating the results of HCl oxidation based on the chemical similarity of these reactions. Interestingly, despite its inactivity in HCl oxidation, TiO2 was found to be an outstanding HBr oxidation catalyst, which highlighted that the latter reaction is more complex than previously assumed. Herein, we discuss the results of recent comparative studies of HCl and HBr oxidation on both rutile-type (RuO2, IrO2, and TiO2) and ceria-based catalysts using a combination of advanced experimental and theoretical methods to provide deeper molecular-level understanding of the reactions. This knowledge aids the design of the next-generation catalysts for halogen recycling. PMID:27131113

  20. Wetting heterogeneity in mixed-wet porous media controls flow dissipation

    CERN Document Server

    Murison, Julie; Baret, Jean-Christophe; Herminghaus, Stephan; Schröter, Matthias; Brinkmann, Martin

    2013-01-01

    Wettability is crucial for multiphase flow in porous media. However, the effect of spatial distribution of wetting domains has previously only been dealt with by averaging contact angles over several pores. By preparing tailored bead packings with the same average surface wettability, but differing in the typical spatial extension of the same-type wetting domains, we show that models based solely on averages do not capture the dynamics of two phase flow in such systems. Using X-ray tomography we measure the typical length scale xi of the wetting domains in our samples. In capillary pressure saturation (CPS) experiments we find that xi controls the width of the hysteresis loop for xi <= d, d being the bead diameter. X-Ray tomography of the samples during both water and oil invasion shows that the front morphology is smoothened at small values of xi. Both observations are consistent with an increase of dissipation for small correlation length.

  1. Synthesis and catalytic property of Cu-Mn-Ce/ γ -Al2O3 complex oxide

    Institute of Scientific and Technical Information of China (English)

    黄可龙; 王红霞; 刘素琴; 桂客

    2002-01-01

    A new type of catalytic material for purification of automobile exhaust,Cu-Mn-Ce-O/ γ -Al2O3,has been studied.The factors affecting its catalytic activity,such as calcination temperature and the period of calcinations and so on have been investigated.Its catalytic activity after SO2-poisoning was determined in a fixed-bed reactor by exposing the sample to the atmosphere of 160 mL/min SO2/air.The study reveals that the catalyst has shown high catalytic activities for the conversion of NH3 oxidation by NO after sulfate.The conversion of NO reduction over the sulfated catalyst is somewhat higher than that over the fresh catalyst except that the optimum temperature has increased about 100 ℃.Also at the optimum process for the experiment,the selective catalytic oxidation of CO by NO is over 76% and the conversion of NO reduction is over 80% by NH3.

  2. Catalytic models developed through social work

    DEFF Research Database (Denmark)

    Jensen, Mogens

    2015-01-01

    The article develops the concept of catalytic processes in relation to social work with adolescents in an attempt to both reach a more nuanced understanding of social work and at the same time to develop the concept of catalytic processes in psychology. The social work is pedagogical treatment...... of adolescents placed in out-of-home care and is characterised using three situated cases as empirical data. Afterwards the concept of catalytic processes is briefly presented and then applied in an analysis of pedagogical treatment in the three cases. The result is a different conceptualisation of the social...... work with new possibilities of development of the work, but also suggestions for development of the concept of catalytic processes....

  3. Morphology-dependent field emission properties and wetting behavior of ZnO nanowire arrays

    Directory of Open Access Journals (Sweden)

    Ma Li

    2011-01-01

    Full Text Available Abstract The fabrication of three kinds of ZnO nanowire arrays with different structural parameters over Au-coated silicon (100 by facile thermal evaporation of ZnS precursor is reported, and the growth mechanism are proposed based on structural analysis. Field emission (FE properties and wetting behavior were revealed to be strongly morphology dependent. The nanowire arrays in small diameter and high aspect ratio exhibited the best FE performance showing a low turn-on field (4.1 V/μm and a high field-enhancement factor (1745.8. The result also confirmed that keeping large air within the films was an effective way to obtain super water-repellent properties. This study indicates that the preparation of ZnO nanowire arrays in an optimum structural model is crucial to FE efficiency and wetting behavior.

  4. MOBILE COMPLEX FOR CATALYTIC THERMAL WASTE TREATMENT

    Directory of Open Access Journals (Sweden)

    Vedi V.E.

    2012-12-01

    Full Text Available The design and purpose of the basic units of the mobile waste processing complex “MPK” are described. Experimental data of catalytic purification of exhaust gases are presented. Experimental data on catalytic clearing of final gases of a designed mobile incinerator plant are shown. It is defined, that concentrating of parasitic bridging in waste gases of the complex are considerably smaller, rather than allowed by normative documents.

  5. MOBILE COMPLEX FOR CATALYTIC THERMAL WASTE TREATMENT

    OpenAIRE

    Vedi V.E.; Rovenskii A.I.

    2012-01-01

    The design and purpose of the basic units of the mobile waste processing complex “MPK” are described. Experimental data of catalytic purification of exhaust gases are presented. Experimental data on catalytic clearing of final gases of a designed mobile incinerator plant are shown. It is defined, that concentrating of parasitic bridging in waste gases of the complex are considerably smaller, rather than allowed by normative documents.

  6. Catalytic Radical Domino Reactions in Organic Synthesis

    Science.gov (United States)

    Sebren, Leanne J.; Devery, James J.; Stephenson, Corey R.J.

    2014-01-01

    Catalytic radical-based domino reactions represent important advances in synthetic organic chemistry. Their development benefits synthesis by providing atom- and step-economical methods to complex molecules. Intricate combinations of radical, cationic, anionic, oxidative/reductive, and transition metal mechanistic steps result in cyclizations, additions, fragmentations, ring-expansions, and rearrangements. This Perspective summarizes recent developments in the field of catalytic domino processes. PMID:24587964

  7. Catalytic ammonia oxidation to nitrogen (I) oxide

    OpenAIRE

    MASALITINA NATALIYA YUREVNA; SAVENKOV ANATOLIY SERGEEVICH

    2015-01-01

    The process of synthesis of nitrous oxide by low-temperature catalytical oxidation of NH has been investigated for organic synthesis. The investigation has been carried out by the stage separation approach with NH oxidation occurring in several reaction zones, which characterized by different catalytic conditions. The selectivity for N₂O was 92–92,5 % at the ammonia conversion of 98–99.5 % in the optimal temperature range.

  8. Temperature Modulation of a Catalytic Gas Sensor

    OpenAIRE

    Eike Brauns; Eva Morsbach; Sebastian Kunz; Marcus Baeumer; Walter Lang

    2014-01-01

    The use of catalytic gas sensors usually offers low selectivity, only based on their different sensitivities for various gases due to their different heats of reaction. Furthermore, the identification of the gas present is not possible, which leads to possible misinterpretation of the sensor signals. The use of micro-machined catalytic gas sensors offers great advantages regarding the response time, which allows advanced analysis of the sensor response. By using temperature modulation, additi...

  9. Preparation and Catalytic Oxidation Activity on 2-mercaptoethanol of a Novel Catalytic Cellulose Fibres

    Institute of Scientific and Technical Information of China (English)

    YAO Yu-yuan; LI Ying-jie; CHEN Wen-xing; Lü Wang-yang; Lü Su-fang; XU Min-hong; LIU Fan

    2007-01-01

    Cobalt tetra(N-carbonylacylic) aminophthalocyanine was supported on cellulose fibres by graft reaction to obtain a novel polymer catalyst, catalytic cellulose fibres (CCF),and the optimal supporting conditions were pH = 6, 80℃,t = 120 min. The catalytic oxidation activity of CCF towards oxidation of 2-mereaptoethanol (MEA) in aqueous solution was investigated. The experimental results demonstrated that CCF had good catalytic oxidation activity on MEA at room temperature, causing no secondary pollution and remaining efficient for the repetitive tests with no obvious decrease of catalytic activity.

  10. Stable, Electroinactive Wetting Agent For Fuel Cells

    Science.gov (United States)

    Prakash, Surya G.; Olah, George A.; Narayanan, Sekharipuram R.; Surampudi, Subbarao; Halpert, Gerald

    1994-01-01

    Straight-chain perfluorooctanesulfonic acid (C8 acid) identified as innocuous and stable wetting agent for use with polytetrafluoroethylene-containing electrodes in liquid-feed direct-oxidation fuel cells suggested for use in vehicles and portable power supplies. C8 acid in small concentrations in aqueous liquid solutions of methanol, trimethoxymethane, dimethoxymethane, and trioxane enables oxidation of these substances by use of commercially available electrodes of type designed originally for use with gases. This function specific to C8 acid molecule and not achieved by other related perfluorolkanesulfonic acids.

  11. Wet oxidation processes for water pollution remediation

    OpenAIRE

    García Molina, Verónica

    2006-01-01

    [eng] The main objective of this work was to test the efficiency of wet oxidation processes when treating several types of aqueous wastes. On one side its performance for the abatement of chloro-organic aromatic toxic pollutants, such as 4-chlorophenol and 2,4-dichlorophenol has been studied. On the other hand, wastewater from pulp and paper mills, which has been reported to be an indirect source of entry of chlorophenols in the aquatic environment, has been investigated. More in detail, it h...

  12. Coefficient of Restitution of Wet Tennis Balls

    OpenAIRE

    Eugene Jang; Tony Kim

    2014-01-01

    The coefficient of restitution of a damp tennis ball is of interest to tennis players. Using a spray bottle, water was added to a tennis ball and the mass of water on the wet ball was determined. The ball was then dropped from a fixed height of 0.86 m. The motion was recorded with a video camera and the bounce height was measured. Using the bounce height and the original height, the coefficient of restitution for that mass of added water was determined. The research found the mass of wa...

  13. Low efficiency deasphalting and catalytic cracking

    International Nuclear Information System (INIS)

    This patent describes a process for converting an asphaltene and metals containing heavy hydrocarbon feed to lighter, more valuable products the metals comprising Ni and V. It comprises: demetallizing the feed by deasphalting the feed in a solvent deasphalting means operating at solvent deasphalting conditions including a solvent: feed volume ratio of about 1:1 to 4:1, using a solvent selected from the group of C4 to 400 degrees F. hydrocarbons and mixtures thereof; recovering from the solvent rich fraction a demetallized oil intermediate product, having a boiling range and containing at least 10 wt.% of the asphaltenes, and 5 to 30% of the Ni and V, and at least 10 wt.% of the solvent present in the solvent rich phase produced in the deasphalting means; catalytically cracking the demetallized oil intermediate product in a catalytic cracking means operating at catalytic cracking conditions to produce a catalytically cracked product vapor fraction having a lower boiling range than the boiling range of the demetallized oil intermediate product; and fractionating the catalytically cracked product in a fractionation means to produce catalytically cracked product fractions

  14. Ignition strategies for fuel mixtures in catalytic microburners

    Science.gov (United States)

    Seshadri, Vikram; Kaisare, Niket S.

    2010-03-01

    Ignition of methane-air and propane-air mixtures over platinum catalyst in a parallel-plate microburner is studied numerically and a comparison of their ignition characteristics is presented. The ignition behaviour of the two fuels is compared for the case of heated feed and the strategy of using propane-methane mixed fuel is analysed. We show that adding small quantities of propane reduces the ignition temperature of lean methane-air mixture. Transient response of the mixed methane-propane fuel reveals sequential ignition of propane followed by methane. Sensitivity analysis on physical properties of methane and propane shows that the higher apparent activation energy of methane combustion accounts for most of the observed differences in their ignition behaviour. Ignition by resistive preheating, specifically the effect of locally preheating initial section of the burner is investigated. The amount of electric power required for ignition decreases with decrease in the electrical preheating length. This reduction in ignition power is especially significant for low conductivity walls, compared to highly conducting walls. Finally, the gap size of the channel has a relatively small effect on ignition in catalytic microburners.

  15. Catalytic hydrogenation of carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Wayland, B.B.

    1992-12-01

    This project is focused on developing strategies to accomplish the reduction and hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. Our approaches to this issue are based on the recognition that rhodium macrocycles have unusually favorable thermodynamic values for producing a series of intermediate implicated in the catalytic hydrogenation of CO. Observations of metalloformyl complexes produced by reactions of H{sub 2} and CO, and reductive coupling of CO to form metallo {alpha}-diketone species have suggested a multiplicity of routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in constructing energy profiles for a variety of potential pathways, and these schemes are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Variation of the electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Emerging knowledge of the factors that contribute to M-H, M-C and M-O bond enthalpies is directing the search for ligand arrays that will expand the range of metal species that have favorable thermodynamic parameters to produce the primary intermediates for CO hydrogenation. Studies of rhodium complexes are being extended to non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics. Multifunctional catalyst systems designed to couple the ability of rhodium complexes to produce formyl and diketone intermediates with a second catalyst that hydrogenates these imtermediates are promising approaches to accomplish CO hydrogenation at mild conditions.

  16. Reactive wetting by liquid sodium on thin Au platin

    International Nuclear Information System (INIS)

    For practical use of an under-sodium viewer, the behavior of sodium wetting is investigated by modeling the reactive and non-reactive wetting of metallic-plated steels by liquid sodium to simulate sodium wetting. The non-reactive wetting simulation results showed good agreement with Tanner's law, in which the time dependencies of the droplet radius and contact angle are expressed as RN ∝ t1/10 and θ∝ t-3/10, respectively; therefore, the model was considered suitable for the simulation. To simulate reactive wetting, the model of fluid flow induced by the interfacial reaction was incorporated into the simulation of non-reactive wetting. The reactive wetting simulation results, such as the behavior of the precursor liquid film and central droplet, showed good agreement with sodium wetting experiments using thin Au plating at 250°C. An important result of the reactive wetting simulation is that the gradient of the reaction energy at the interface appeared on the new interface around the triple line, and that fluid flow was induced. This interfacial reactivity during sodium wetting of thin Au plating was enhanced by the reaction of sodium and nickel oxide through pinholes in the plating. (author)

  17. Development studies for a novel wet oxidation process. Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-07-01

    DETOX{sup SM} is a catalyzed wet oxidation process which destroys organic materials in an acidic water solution of iron at 373 to 473 K. The solution can be used repeatedly to destroy great amounts of organic materials. Since the process is conducted in a contained vessel, air emissions from the process can be well controlled. The solution is also capable of dissolving and concentrating many heavy and radioactive metals for eventual stabilization and disposal. The Phase 2 effort for this project is site selection and engineering design for a DETOX demonstration unit. Site selection was made using a set of site selection criteria and evaluation factors. A survey of mixed wastes at DOE sites was conducted using the Interim Mixed Waste Inventory Report. Sites with likely suitable waste types were identified. Potential demonstration sites were ranked based on waste types, interest, regulatory needs, scheduling, ability to provide support, and available facilities. Engineering design for the demonstration unit is in progress and is being performed by Jacobs Applied Technology. The engineering design proceeded through preliminary process flow diagrams (PFDs), calculation of mass and energy balances for representative waste types, process and instrumentation diagrams (P and IDs), preparation of component specifications, and a firm cost estimate for fabrication of the demonstration unit.

  18. Atmospheric transport and wet deposition of ammonium in North Carolina

    Science.gov (United States)

    Walker, John T.; Aneja, Viney P.; Dickey, David A.

    Wet deposition and transport analysis has been performed for ammonium (NH 4+) in North Carolina, USA. Multiple regression analysis is employed to model the temporal trend and seasonality in monthly volume-weighted mean NH 4+ concentrations in precipitation from 1983 to 1996 at six National Atmospheric Deposition Program/National Trends Network (NADP/NTN) sites. A significant ( ppopulated network of swine and poultry operations. This trend is positively correlated with increasing ammonia (NH 3) emissions related to the vigorous growth of North Carolina's swine population since 1990, particularly in the state's Coastal Plain region. A source-receptor regression model, which utilizes weekly NH 4+ concentrations in precipitation in conjunction with boundary layer air mass back trajectories, is developed to statistically test for the influence of a particular NH 3 source region on NH 4+ concentrations at surrounding NADP/NTN sites for the years 1995-1996. NH 3 emissions from this source region, primarily evolving from swine and poultry operations, are found to increase NH 4+ concentration in precipitation at sites up to ≈80 km away. At the Scotland County (NC36) and Wake County (NC41) sites, mean NH 4+ concentrations show increases of at least 44% for weeks during which 25% or more back trajectories are influenced by this source region.

  19. [Fe-ZSM-5 catalysts with different silica-alumina ratios for N2O, catalytic decomposition].

    Science.gov (United States)

    Lu, Ren-Jie; Zhang, Xin-Yan; Hao, Zheng-Ping

    2014-01-01

    The Fe-ZSM-5 catalysts were prepared with H-ZSM-5 of different Si/Al ratios by wet ion exchange and chemical vapor deposition. Then the catalysts were investigated by XRD, BET, TEM, UV-vis and NH3-TPD technologies to analyze the iron states in Fe-ZSM-5 zeolites. The results showed that after H-ZSM-5 zeolites were prepared by chemical vapor deposition and heating wet ion exchange, the nano Fe2 O3 particles were uniformly dispersed with the sizes of 8 nm in the Fe-ZSM-5-25 (Si/A1-25). Moreover, there were more oligonuclear Fe3+ Oy clusters in the Fe-ZSM-5-25 catalysts than in Fe-ZSM-5-300 (Si/Al-300). The results of catalytic performance on N2O decomposition showed that Fe-ZSM-5-25 catalysts had higher catalytic activities than Fe-ZSM-5-300 catalysts. The Fe-ZSM-5 catalysts prepared by chemical vapor deposition achieved the best catalytic activity in N2O decomposition among the catalysts prepared by the three methods. Moreover, the presence of O2 only slightly reduced N2O conversion, while NO promoted the N2O decomposition. Finally, after reaction for more than 100 h, Fe-ZSM-5 catalyst showed no obvious deactivation under simulated emission conditions. PMID:24720229

  20. Wenzel Wetting on Slippery Rough Surfaces

    Science.gov (United States)

    Stogin, Birgitt; Dai, Xianming; Wong, Tak-Sing

    2015-11-01

    Liquid repellency is an important surface property used in a wide range of applications including self-cleaning, anti-icing, anti-biofouling, and condensation heat transfer, and is characterized by apparent contact angle (θ*) and contact angle hysteresis (Δθ*). The Wenzel equation (1936) predicts θ* of liquids in the Wenzel state, and is one of the most fundamental equations in the wetting field. However, droplets in the Wenzel state on conventional rough surfaces exhibit large Δθ* , making it difficult to experimentally verify the model with precision. As a result, precise verification of the Wenzel wetting model has remained an open scientific question for the past 79 years. Here we introduce a new class of liquid-infused surfaces called slippery rough surfaces -- surfaces with significantly reduced Δθ* compared to conventional rough surfaces--and use them to experimentally assess the Wenzel equation with the highest precision to date. We acknowledge the funding support by National Science Foundation (NSF) CAREER Award #: 1351462 and Office of Navy Research MURI Award #: N00014-12-1-0875. Stogin acknowledges the support from the NSF Graduate Research Fellowship (Grant No. DGE1255832).