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Sample records for catalytic rich gas process

  1. Process for catalytic flue gas denoxing

    International Nuclear Information System (INIS)

    With the increasing concern for the environment, stringency of legislation and industry's awareness of its own environmental responsibility, the demand for the reduction of emission levels of nitrogen oxides is becoming increasingly urgent. This paper reports that Shell has developed a low temperature catalytic deNOx system for deep removal of nitrogen oxides, which includes a low-pressure-drop reactor. This process is able to achieve over 90% removal of nitrogen oxides and therefore can be expected to meet legislation requirements for the coming years. The development of a low-temperature catalyst makes it possible to operate at temperatures as low as 120 degrees C, compared to 300-400 degrees C for the conventional honeycomb and plate-type catalysts. This allows an add-on construction, which is most often a more economical solution than the retrofits in the hot section required with conventional deNOx catalysts. The Lateral Flow Reactor (LFR), which is used for dust-free flue gas applications, and the Parallel Passage Reactor (PPR) for dust-containing flue gas applications, have been developed to work with pressure drops below 10 mbar

  2. A catalytic distillation process for light gas oil hydrodesulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Vargas-Villamil, F.D.; Marroquin, J.O.; Paz, C. de la; Rodriguez, E. [Prog. de Matematicas Aplicadas y Computacion, Prog. de Tratamiento de Crudo Maya, Instituto Mexicano del Petroleo, Mexico City, DF (Mexico)

    2004-07-01

    A light gas oil hydrodesulfurization process via catalytic distillation is developed and compared to a conventional process. By integrating the separation and reaction into a single unit, the catalytic distillation may produce a diesel with low concentration of sulfur compounds at a lower cost than the traditional reaction/separation process. The process proposed in this work is compared to an optimised conventional hydrodesulfurization unit which represents fairly well a plant that belongs to the National System of Refineries. During the optimisation of the conventional process, a compromise is established among the production of diesel and naphtha and the operating costs. The results show that the light gas oil hydrodesulfurization via catalytic distillation is as or more efficient than the conventional process. However, the removal of the sulfur compounds is carried out under less rigorous conditions. This design reduces the fix and operational costs. (author)

  3. Hazelnut shell to hydrogen-rich gaseous products via catalytic gasification process

    Energy Technology Data Exchange (ETDEWEB)

    Demirbas, A. [Selcuk Univ., Dept. of Chemical Engineering, Konya (Turkey)

    2004-01-15

    The gasification of biomass is a thermal treatment, which results in a high production of gaseous products and small quantities of char and ash. Steam reforming of hydrocarbons, partial oxidation of heavy oil residues, selected steam reforming of aromatic compounds, and gasification of coals and solid wastes to yield a mixture of H{sub 2} and CO (syngas), followed by a water-gas shift reaction to produce H{sub 2} and CO{sub 2}, are well-established processes. The samples, both untreated and impregnated with a catalyst, were pyrolyzed and gasified at 770, 925, 975, and 1025 K, and 975, 1075, 1175, and 1225 K temperatures, respectively. K{sub 2}CO{sub 3} was used as a catalyst, 10.0, 20.0, 30.0, and 50.0 wt% of the shell sample, in the catalytic-pyrolysis runs. The ratios of water-to-hazelnut shell were 0.7 and 1.9 in steam gasification runs. The total volume and the yield of gas from both pyrolysis and gasification increase with increasing temperature. The highest hydrogen-rich gas yield was obtained from the catalytic gasification run (water/hazelnut shell = 1.9) at 1225 K. (Author)

  4. System Study of Rich Catalytic/Lean burn (RCL) Catalytic Combustion for Natural Gas and Coal-Derived Syngas Combustion Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Shahrokh Etemad; Lance Smith; Kevin Burns

    2004-12-01

    Rich Catalytic/Lean burn (RCL{reg_sign}) technology has been successfully developed to provide improvement in Dry Low Emission gas turbine technology for coal derived syngas and natural gas delivering near zero NOx emissions, improved efficiency, extending component lifetime and the ability to have fuel flexibility. The present report shows substantial net cost saving using RCL{reg_sign} technology as compared to other technologies both for new and retrofit applications, thus eliminating the need for Selective Catalytic Reduction (SCR) in combined or simple cycle for Integrated Gasification Combined Cycle (IGCC) and natural gas fired combustion turbines.

  5. Selective catalytic oxidation of NH3 to N2 for catalytic combustion of low heating value gas under lean/rich conditions

    International Nuclear Information System (INIS)

    The selective catalytic oxidation (SCO) of ammonia to nitrogen has been examined over 5% Fe/Al2O3, 5% Mn/Al2O3, 20% CuO/Al2O3, 1% Pt/20% CuO/Al2O3, 2% Rh/Al2O3 and a Fe zeolite (Fe-SH-27) under fuel-lean and fuel-rich conditions in a monolith lab-scale reactor. For simulating fuel-bound nitrogen in a low heating value (LHV) gas 400ppm NH3 was added to the test gas. The SCO performance of the catalysts was tested both with and without water added to the gas stream. For SCO under fuel-lean conditions the Fe-zeolite catalyst exhibited the lowest NOx yield. For SCO under fuel-rich conditions the 20% CuO/Al2O3 was superior with close to zero NOx formation

  6. Catalytic processes during preferential oxidation of CO in H 2-rich streams over catalysts based on copper-ceria

    Science.gov (United States)

    Gamarra, D.; Hornés, A.; Koppány, Zs.; Schay, Z.; Munuera, G.; Soria, J.; Martínez-Arias, A.

    Nanostructured catalysts based on combinations between oxidised copper and cerium entities prepared by two different methods (impregnation of ceria and coprecipitation of the two components within reverse microemulsions) have been examined with respect to their catalytic performance for preferential oxidation of CO in a H 2-rich stream (CO-PROX). Correlations between their catalytic and redox properties are established on the basis of parallel analyses of temperature programmed reduction results employing both H 2 and CO as reactants as well as by XPS. Although general catalytic trends can be directly correlated with the redox properties observed upon separate interactions with each of the two reductants (CO and H 2), the existence of interferences between both reductants must be considered to complete details for such activity/redox correlation. Differences in the nature of the active oxidised copper-cerium contacts present in each case determine the catalytic properties of these systems for the CO-PROX process.

  7. Catalytic cracking process

    Science.gov (United States)

    Lokhandwala, Kaaeid A.; Baker, Richard W.

    2001-01-01

    Processes and apparatus for providing improved catalytic cracking, specifically improved recovery of olefins, LPG or hydrogen from catalytic crackers. The improvement is achieved by passing part of the wet gas stream across membranes selective in favor of light hydrocarbons over hydrogen.

  8. Process analysis of syngas production by non-catalytic POX of oven gas

    Institute of Scientific and Technical Information of China (English)

    Fuchen WANG; Xinwen ZHOU; Wenyuan GUO; Zhenghua DAI; Xin GONG; Haifeng LIU; Guangsuo YU; Zunhong YU

    2009-01-01

    A non-catalytic POX of oven gas is proposed to solve the problem of secondary pollution due to solid wastes produced from the great amount of organic sulfur contained in oven gas in the traditional catalytic partial oxidation (POX) process. A study of the measurement of flow field and a thermodynamic analysis of the process characteristics were conducted. Results show that there exist a jet-flow region, a recirculation-flow region, a tube-flow region, and three corresponding reaction zones in the non-catalytic POX reformer. The combustion of oven gas occurs mainly in the jet-flow region, while the reformation of oven gas occurs mainly in the other two regions. Soot would not be formed by CH4 cracking at above 1200℃. Since there are very little C2+ hydrocarbons in oven gas, the soot produced would be very tiny, even if they underwent cracking reaction. The integrated model for entrained bed gasification process was applied to simulate a non-catalytic POX reformer. It indicated that the proper oxygen-to-oven gas ratio is 0.22-0.28 at differ-ent pressures in the oven gas reformation process.

  9. Reduction of greenhouse gas emissions by catalytic processes

    International Nuclear Information System (INIS)

    Catalytic technologies for the abatement of greenhouse gases (GGs) can be an effective possibility for limiting the increasing tropospheric concentration of GGs and reducing their contribution to global warming. Two different cases are discussed: (1) reduction of anthropogenic emissions of non-CO2 GGs (N2O and CH4) and (2) reduction or conversion of CO2. In methane conversion waste gases containing diluted methane can be converted at low temperature using Pd supported on titania-ceria catalysts which show also a good resistance to deactivation. Rh supported on modified zirconia-alumina catalysts are effective and stable catalysts in low temperature decomposition of N2O. The concept of reduction of CO2 back to fuels in a photo-electrocatalytic reactor is also presented

  10. Catalytic ethanolysis and gasification of kraft lignin into aromatic alcohols and H2-rich gas over Rh supported on La2O3/CeO2-ZrO2.

    Science.gov (United States)

    Yang, Jing; Zhao, Liang; Liu, Chunze; Wang, Yuanyuan; Dai, Liyi

    2016-10-01

    Efficient catalytic ethanolysis and gasification of kraft lignin were conducted over a versatile supported catalyst Rh/La2O3/CeO2-ZrO2 to give high-value aromatic alcohols and H2-rich gas. The removal of phenolic hydroxyl group was the most prevalent reaction, and importantly, almost no phenols, undesired char and saturating the aromatic ring were detected. Meanwhile, the feedstock and solvent both played key roles in H2 generation that contributed to the hydrodeoxygenation of liquid components and made the whole catalytic process out of H2 supply. Reusability tests of catalyst indicated that the crystalline phase transition and agglomeration of support, the loss of noble metal Rh and carbon deposition were the possible reasons for its deactivation in supercritical ethanol. Comparing with water, methanol and isopropanol system, ethanol was the only effective solvent for the depolymerization process. PMID:27441830

  11. Selective Catalytic Oxidation of NH3 to N2 for Catalytic Combustion of Low Heating Value Gas under Lean/Rich Conditions

    Czech Academy of Sciences Publication Activity Database

    Kušar, H.M.J.; Ersson, A.G.; Vosecký, Martin; Järas, S.G.

    2005-01-01

    Roč. 58, 1-2 (2005), s. 25-32. ISSN 0926-3373 Institutional research plan: CEZ:AV0Z40720504 Keywords : catalytic combustion * selective catalytic oxidation * ammonia Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.809, year: 2005

  12. Thermodynamic analysis of a process for producing high-octane gasoline components from catalytic cracking gas

    Science.gov (United States)

    Ismailova, Z. R.; Pirieva, Kh. B.; Kasimov, A. A.; Dzhamalova, S. A.; Gadzhizade, S. M.; Nuriev, Sh. A.; Zeinalova, S. Kh.; Dzhafarov, R. P.

    2016-03-01

    The results from a thermodynamic analysis of high-octane gasoline component production from catalytic cracking gases using zeolite catalyst OMNIKAT-210P modified with Ni, Co, Cr are presented. The equilibrium constants of the reactions assumed to occur in this process are calculated, along with the equilibrium yield of the reactions.

  13. Data acquisition and quantitative analysis of stable hydrogen isotope in liquid and gas in the liquid phase catalytic exchange process

    International Nuclear Information System (INIS)

    A pilot plant for the Liquid Phase Catalytic Exchange process was built and has been operating to test the hydrophobic catalyst developed to remove the tritium generated at the CANDU nuclear power plants. The methods of quantitative analysis of hydrogen stable isotope were compared. Infrared spectroscopy was used for the liquid samples, and gas chromatography with hydrogen carrier gas showed the best result for gas samples. Also, a data acquisition system was developed to record the operation parameters. This record was very useful to investigate the causes of the system trip

  14. Pretreated Landfill Gas Conversion Process via a Catalytic Membrane Reactor for Renewable Combined Fuel Cell-Power Generation

    Directory of Open Access Journals (Sweden)

    Zoe Ziaka

    2013-01-01

    Full Text Available A new landfill gas-based reforming catalytic processing system for the conversion of gaseous hydrocarbons, such as incoming methane to hydrogen and carbon oxide mixtures, is described and analyzed. The exit synthesis gas (syn-gas is fed to power effectively high-temperature fuel cells such as SOFC types for combined efficient electricity generation. The current research work is also referred on the description and design aspects of permreactors (permeable reformers carrying the same type of landfill gas-reforming reactions. Membrane reactors is a new technology that can be applied efficiently in such systems. Membrane reactors seem to perform better than the nonmembrane traditional reactors. The aim of this research includes turnkey system and process development for the landfill-based power generation and fuel cell industries. Also, a discussion of the efficient utilization of landfill and waste type resources for combined green-type/renewable power generation with increased processing capacity and efficiency via fuel cell systems is taking place. Moreover, pollution reduction is an additional design consideration in the current catalytic processors fuel cell cycles.

  15. LHCB RICH gas system proposal

    CERN Document Server

    Bosteels, Michel; Haider, S

    2001-01-01

    Both LHCb RICH will be operated with fluorocarbon as gas radiator. RICH 1 will be filled with 4m^3 of C4F10 and RICH 2 with 100m^3 of CF4. The gas systems will run as a closed loop circulation and a gas recovery system within the closed loop is planned for RICH 1, where the recovery of the CF4 will only be realised during filling and emptying of the detector. Inline gas purification is foreseen for the gas systems in order to limit water and oxygen impurities.

  16. Catalytic seawater flue gas desulfurization process: an experimental pilot plant study

    Energy Technology Data Exchange (ETDEWEB)

    F. Vidal B.; P. Ollero; F.J. Gutierrez Ortiz; A. Villanueva [University of Seville, Seville (Spain). Department of Chemical and Environmental Engineering

    2007-10-15

    In previous articles by the authors on seawater S(IV) oxidation kinetics, a significant catalytic effect was demonstrated by means of a commercially available activated carbon. The aims of this study carried out at pilot plant scale were to assess the use of high-efficiency structured packing and to validate the positive results obtained previously in laboratory studies. A comparison between a packed tower and a spray column was made by maintaining the same desulfurization efficiency. A 47% reduction in seawater flow can be obtained with a packed tower. This option seems to be more economical, with a reduction in operation costs of least of 33%. With the appropriate activated carbon, it is possible to reach a greater oxidation rate at a low pH level than by operating conventionally at a high pH level without a catalyst. A preliminary technical and financial comparison between the advanced seawater desulfurization process (equipped with a packed tower and a catalytic oxidation plant) and the conventional process (spray tower and noncatalytic oxidation) was carried out. 18 refs., 4 figs., 4 tabs.

  17. Removal of P4, PH3 and H2S from Yellow Phosphoric Tail Gas by a Catalytic Oxidation Process

    Institute of Scientific and Technical Information of China (English)

    NingPing; Hans-JoergBart; MaLiping; WangXueqian

    2004-01-01

    Yellow phosphorus tail gas is a resource used to produce bulk chemicals, such as formates, oxalates, and methanol after its pretreatment and purification. In this study, catalytic oxidation of phosphorus and hydrogen sulfide in yellow phosphorus tail gas was investigated on an ordinary activated carbon (OAC) and a home-made catalyst KU2. The adsorption characteristics of phosphorus and hydrogen sulfide on the catalysts were studied in a fixed-bed system at different temperatures between 20℃ and 140℃ at atmospheric pressure. Both KU2 and OAC are proved to be effective catalysts in the catalytic oxidation process (COP) for H2S and PH3 removal. Purification efficiency increased with the increase of temperature and oxygen concentration in yellow phosphorus tail gases. Under optimized operation conditions, the product gases with a content of hydrogen sulfide <5mg/m3 and total phosphorus <5mg/m3 were obtained by using the COP process. Deactivated catalysts could be restored to the original activated state, even after several regenerations. A mathematical model was developed to simulate the experimental results and the mass transport coefficient from the experiment was evaluated. Good agreement between the experimental breakthrough curves and the model predictions was observed.

  18. Catalytic reforming process

    Energy Technology Data Exchange (ETDEWEB)

    Absil, R.P.; Huss, A. Jr.; McHale, W.D.; Partridge, R.D.

    1989-06-13

    This patent describes a catalytic reforming process which comprises contacting a naphtha range feed with a low acidity extrudate comprising an intermediate and/or a large pore acidic zeolite bound with a low acidity refractory oxide under reforming conditions to provide a reaction product of increased aromatic content, the extrudate having been prepared with at least an extrusion-facilitating amount of a low acidity refractory oxide in colloidal form and containing at least one metal species selected from the platinum group metals.

  19. Catalytic hot gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P. [VTT Energy, Espoo (Finland)

    1996-12-31

    Gasification gas that contains particulates can be purified from tars and ammonia by using nickel monolith catalysts. Temperatures over 900 deg C are required at 20 bar pressure to avoid deactivation by H{sub 2}S and carbon. Dolomites and limestones are effective tar decomposing catalysts only when calcined. Tar decomposition in gasification conditions can take place by steam or dry (CO{sub 2}) reforming reactions. These reactions follow apparent first order kinetics with respect to hydrocarbons in gasification conditions. (author) (16 refs.)

  20. Selective catalytic reduction system and process for control of NO.sub.x emissions in a sulfur-containing gas stream

    Science.gov (United States)

    Sobolevskiy, Anatoly

    2015-08-11

    An exhaust gas treatment process, apparatus, and system for reducing the concentration of NOx, CO and hydrocarbons in a gas stream, such as an exhaust stream (29), via selective catalytic reduction with ammonia is provided. The process, apparatus and system include a catalytic bed (32) having a reducing only catalyst portion (34) and a downstream reducing-plus-oxidizing portion (36). Each portion (34, 36) includes an amount of tungsten. The reducing-plus-oxidizing catalyst portion (36) advantageously includes a greater amount of tungsten than the reducing catalyst portion (36) to markedly limit ammonia salt formation.

  1. Thermodynamic Feasibility of Hydrogen-Rich Gas Production Supported by Iron Based Chemical Looping Process

    Directory of Open Access Journals (Sweden)

    Grzegorz Słowiński

    2016-01-01

    Full Text Available The continuously increasing oil prices as well as stronger environmental regulations regarding greenhouse emissions made the greatest economic powers search a new, price competitive, and environment friendly energy carrier, such as hydrogen. The world research activities in these terms focus on the development of integrated hydrogen and power generating technologies, particularly technologies of hydrogen production from various carbonaceous resources, like methane, coal, biomass, or waste, often combined with carbon dioxide capture. In the paper the thermodynamic analysis of the enhancement of hydrogen production in iron based chemical looping process is presented. In this method, iron oxide is first reduced to iron with a reducing agent, such as carbon oxide, hydrogen, or mixture of both gases (synthesis gas, and then, in the inverse reaction with steam, it is regenerated to iron oxide, and pure stream of hydrogen is produced.

  2. 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.

  3. Catalytic hot gas cleaning of gasification gas

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1997-12-31

    The aim of this work was to study the catalytic cleaning of gasification gas from tars and ammonia. In addition, factors influencing catalytic activity in industrial applications were studied, as well as the effects of different operation conditions and limits. Also the catalytic reactions of tar and ammonia with gasification gas components were studied. The activities of different catalyst materials were measured with laboratory-scale reactors fed by slip streams taken from updraft and fluid bed gasifiers. Carbonate rocks and nickel catalysts proved to be active tar decomposing catalysts. Ammonia decomposition was in turn facilitated by nickel catalysts and iron materials like iron sinter and iron dolomite. Temperatures over 850 deg C were required at 2000{sup -1} space velocity at ambient pressure to achieve almost complete conversions. During catalytic reactions H{sub 2} and CO were formed and H{sub 2}O was consumed in addition to decomposing hydrocarbons and ammonia. Equilibrium gas composition was almost achieved with nickel catalysts at 900 deg C. No deactivation by H{sub 2}S or carbon took place in these conditions. Catalyst blocking by particulates was avoided by using a monolith type of catalyst. The apparent first order kinetic parameters were determined for the most active materials. The activities of dolomite, nickel catalyst and reference materials were measured in different gas atmospheres using laboratory apparatus. This consisted of nitrogen carrier, toluene as tar model compound, ammonia and one of the components H{sub 2}, H{sub 2}O, CO, CO{sub 2}, CO{sub 2}+H{sub 2}O or CO+CO{sub 2}. Also synthetic gasification gas was used. With the dolomite and nickel catalyst the highest toluene decomposition rates were measured with CO{sub 2} and H{sub 2}O. In gasification gas, however, the rate was retarded due to inhibition by reaction products (CO, H{sub 2}, CO{sub 2}). Tar decomposition over dolomite was modelled by benzene reactions with CO{sub 2}, H

  4. 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.

  5. Industrial Gas Turbine Engine Catalytic Pilot Combustor-Prototype Testing

    Energy Technology Data Exchange (ETDEWEB)

    Etemad, Shahrokh [Precision Combustion, Inc., North Haven, CT (United States); Baird, Benjamin [Precision Combustion, Inc., North Haven, CT (United States); Alavandi, Sandeep [Precision Combustion, Inc., North Haven, CT (United States); Pfefferle, William [Precision Combustion, Inc., North Haven, CT (United States)

    2010-04-01

    PCI has developed and demonstrated its Rich Catalytic Lean-burn (RCL®) technology for industrial and utility gas turbines to meet DOE's goals of low single digit emissions. The technology offers stable combustion with extended turndown allowing ultra-low emissions without the cost of exhaust after-treatment and further increasing overall efficiency (avoidance of after-treatment losses). The objective of the work was to develop and demonstrate emission benefits of the catalytic technology to meet strict emissions regulations. Two different applications of the RCL® concept were demonstrated: RCL® catalytic pilot and Full RCL®. The RCL® catalytic pilot was designed to replace the existing pilot (a typical source of high NOx production) in the existing Dry Low NOx (DLN) injector, providing benefit of catalytic combustion while minimizing engine modification. This report discusses the development and single injector and engine testing of a set of T70 injectors equipped with RCL® pilots for natural gas applications. The overall (catalytic pilot plus main injector) program NOx target of less than 5 ppm (corrected to 15% oxygen) was achieved in the T70 engine for the complete set of conditions with engine CO emissions less than 10 ppm. Combustor acoustics were low (at or below 0.1 psi RMS) during testing. The RCL® catalytic pilot supported engine startup and shutdown process without major modification of existing engine controls. During high pressure testing, the catalytic pilot showed no incidence of flashback or autoignition while operating over a wide range of flame temperatures. In applications where lower NOx production is required (i.e. less than 3 ppm), in parallel, a Full RCL® combustor was developed that replaces the existing DLN injector providing potential for maximum emissions reduction. This concept was tested at industrial gas turbine conditions in a Solar Turbines, Incorporated high-pressure (17 atm.) combustion rig and in a modified Solar

  6. 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...

  7. Catalytic extraction processing of contaminated scrap metal

    International Nuclear Information System (INIS)

    Molten Metal Technology was awarded a contract to demonstrate the applicability of the Catalytic Extraction Process, a proprietary process that could be applied to US DOE's inventory of low level mixed waste. This paper is a description of that technology, and included within this document are discussions of: (1) Program objectives, (2) Overall technology review, (3) Organic feed conversion to synthetic gas, (4) Metal, halogen, and transuranic recovery, (5) Demonstrations, (6) Design of the prototype facility, and (7) Results

  8. Catalytic Processes in Biorefinery

    OpenAIRE

    Vitiello, Rosa

    2015-01-01

    The biorefinery is a system that uses as feedstocks biomasses and recover from these energy, fuel and chemicals. There are many processes considered in the biorefinery system, but in this thesis the biorefinery that uses as feedstock oil, in particular dedicated crops and waste vegetable oils were considered. In the first part of this thesis the biodiesel production process was studied. One possible route to produce biodiesel from waste oils (carachetrized by high concentrations of Fr...

  9. Catalytic O2- and NOsub(x)-removal: a process step for an off-gas cleaning system in reprocessing plants

    International Nuclear Information System (INIS)

    The last step of an off-gas purification system for future reprocessing plants of spent nuclear fuels is the retention of the radioactive krypton. If a cryogenic distillation process is chosen for this step, O2 and NOsub(x) must be removed prior to the cryogenic part in order to avoid radiolytic formation of ozone and crystallization problems, respectively. Simultaneous catalytic reduction with H2 was chosen using ruthenium on A12O3 as catalyst. The process step was tested in a semiscale unit with a gas throughput of 50 m3/h. The feed-gas was diluted by N2 in a gas loop by a factor of 10, to prevent formation of explosive gas mixtures. Residual O2- and NOsub(x)-concentrations 1 ppmv were attained routinely in the temperature range of the catalyst between 3500C and 5500C and at space velocities (GHVS) between 10000 and 15000 h-1. Formation of CH4 is very low (2O). H2 feed control is carried out by means of chemical analysis of O2 and NOsub(x) in the feed gas by calculating the necessary H2 amount and controlling the main H2-valve with a microcomputer. An additional small H2-valve is controlled by analysis of the H2 excess behind the catalyst bed. Even large concentration transients of O2 and NOsub(x) can thus be handled by the catalyst without breakthrough. (author)

  10. 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.

  11. Partitioning of mercury, arsenic, selenium, boron, and chloride in a full-scale coal combustion process equipped with selective catalytic reduction, electrostatic precipitation, and flue gas desulfurization systems

    Energy Technology Data Exchange (ETDEWEB)

    Chin-Min Cheng; Pauline Hack; Paul Chu; Yung-Nan Chang; Ting-Yu Lin; Chih-Sheng Ko; Po-Han Chiang; Cheng-Chun He; Yuan-Min Lai; Wei-Ping Pan [Western Kentucky University, Bowling Green, KY (United States). Institute for Combustion Science and Environmental Technology

    2009-09-15

    A full-scale field study was carried out at a 795 MWe coal-fired power plant equipped with selective catalytic reduction (SCR), an electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD) systems to investigate the distribution of selected trace elements (i.e., mercury, arsenic, selenium, boron, and chloride) from coal, FGD reagent slurry, makeup water to flue gas, solid byproduct, and wastewater streams. Flue gases were collected from the SCR outlet, ESP inlet, FGD inlet, and stack. Concurrent with flue gas sampling, coal, bottom ash, economizer ash, and samples from the FGD process were also collected for elemental analysis. By combining plant operation parameters, the overall material balances of selected elements were established. The removal efficiencies of As, Se, Hg, and B by the ESP unit were 88, 56, 17, and 8%, respectively. Only about 2.5% of Cl was condensed and removed from flue gas by fly ash. The FGD process removed over 90% of Cl, 77% of B, 76% of Hg, 30% of Se, and 5% of As. About 90% and 99% of the FGD-removed Hg and Se were associated with gypsum. For B and Cl, over 99% were discharged from the coal combustion process with the wastewater. Mineral trona (trisodium hydrogendicarbonate dehydrate, Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O) was injected before the ESP unit to control the emission of sulfur trioxide (SO{sub 3}). By comparing the trace elements compositions in the fly ash samples collected from the locations before and after the trona injection, the injection of trona did not show an observable effect on the partitioning behaviors of selenium and arsenic, but it significantly increased the adsorption of mercury onto fly ash. The stack emissions of mercury, boron, selenium, and chloride were for the most part in the gas phase. 47 refs., 3 figs., 11 tabs.

  12. Catalytic Processes for Clean Hydrogen Production from Hydrocarbons

    OpenAIRE

    ÖNSAN, Zeynep İlsen

    2007-01-01

    Conversion of hydrocarbon fuels to hydrogen with a high degree of purity acceptable for fuel cell operation presents interesting challenges for the design of new selective catalysts and catalytic processes. Natural gas, LPG, gasoline, and diesel are regarded as promising hydrocarbon fuels. Methanol has received attention despite its toxicity, and ethanol has recently become of interest as a much less toxic and renewable resource. Selective catalytic processes considered for commerci...

  13. Catalytic denitrification control process and system for combustion flue gases

    International Nuclear Information System (INIS)

    This patent describes a process for controlling the catalytic dentrification of flue gases by ammonia addition to the flue gas. It comprises withdrawing from a combustion process a flue gas stream containing at least about 20 volume parts NOx per million of flue gas, and controllably adding ammonia gas to the flue gas stream; passing the flue gas and ammonia mixture through a catalytic dentrification unit containing a dentrification catalyst material and reducing the NOx concentration in the flue gas; obtaining a control signal based on process parameter signals including the volume flow rate of the flue gas, and determining the quantity of ammonia initially added to the flue gas so that it is less than the amount theoretically required to reduce all of the NOx in the flue gas; obtaining a trim signal based on comparing the NOx concentration measured in the flue gas downstream of the catalytic dentrification unit and a desired NOx concentration; and providing additional ammonia injection based on the trim signal by adjusting the ammonia addition flow rate as needed to provide the desired reduced NOx concentration being emitted to the atmosphere and to avoid excess ammonia injection and system oscillation

  14. Microwave-assisted catalytic pyrolysis of lignocellulosic biomass for production of phenolic-rich bio-oil.

    Science.gov (United States)

    Mamaeva, Alisa; Tahmasebi, Arash; Tian, Lu; Yu, Jianglong

    2016-07-01

    Catalytic microwave pyrolysis of peanut shell (PT) and pine sawdust (PS) using activated carbon (AC) and lignite char (LC) for production of phenolic-rich bio-oil and nanotubes was investigated in this study. The effects of process parameters such as pyrolysis temperature and biomass/catalyst ratio on the yields and composition of pyrolysis products were investigated. Fast heating rates were achieved under microwave irradiation conditions. Gas chromatography-mass spectrometry (GC-MS) analysis of bio-oil showed that activated carbon significantly enhanced the selectivity of phenolic compounds in bio-oil. The highest phenolics content in the bio-oil (61.19 %(area)) was achieved at 300°C. The selectivity of phenolics in bio-oil was higher for PT sample compared to that of PS. The formation of nanotubes in PT biomass particles was observed for the first time in biomass microwave pyrolysis. PMID:27030958

  15. Catalytic combustion in gas stoves - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Hjelm, Anna-Karin [CATATOR AB, Lund (Sweden)

    2003-06-01

    Several independent studies show that gas stoves to some degree contribute to the indoor emissions of NO{sub x} especially in situations were the ventilation flow is poor. The peak-NO{sub x} concentrations can reach several hundred ppb but the integral concentration seldom exceeds about 20 - 50 ppb, which corresponds to an indoor-outdoor ratio of about 1 - 2.5. Epidemiological studies indicate increasing problems with respiratory symptoms in sensitive people at concentrations as low as 15 ppb of NO{sub 2}. Consequently, the NO{sub x}-concentration in homes where gas stoves are used is high enough to cause health effects. However, in situations where the ventilation flow is high (utilisation of ventilation hoods) the NO{sub x}-emissions are not likely to cause any health problems. This study has been aimed at investigating the possibilities to reduce the NO{sub x} emissions from gas stoves by replacing the conventional flame combustion with catalytic combustion. The investigation is requested by Swedish Gas Center, and is a following-up work of an earlier conducted feasibility study presented in April-2002. The present investigation reports on the possibility to use cheap and simple retro-fit catalytic design suggestions for traditional gas stoves. Experiments have been conducted with both natural and town gas, and parameters such as emissions of NO{sub x}, CO and unburned fuel gas and thermal efficiency, etc, have been examined and are discussed. The results show that it is possible to reduce the NO{sub x} emissions up to 80% by a simple retro-fit installation, without decreasing the thermal efficiency of the cooking plate. The measured source strengths correspond to indoor NO{sub x} concentrations that are below or equal to the average outdoor concentration, implying that no additional detrimental health effects are probable. The drawback of the suggested installations is that the concentration of CO and in some cases also CH{sub 4} are increased in the flue gases

  16. Experimental study on application of high temperature reactor excess heat in the process of coal and biomass co-gasification to hydrogen-rich gas

    International Nuclear Information System (INIS)

    The paper presents the results of the experimental study on the simulated application of HTR (High Temperature Reactor) excess heat in the process of allothermal co-gasification of coal and biomass. The laboratory scale installation with a fixed bed gasifier and auxiliary gasification agents pre-heating system, simulating the utilization of the HTR excess heat, were applied in the study. Steam and oxygen were the gasification media employed, and the process was focused on hydrogen-rich gas production. The results of the co-gasification of fuel blends of various biomass content at 800 °C and in various system configurations proved that the application of the simulated HTR excess heat in pre-heating of the gasification agents leads to the increase in the gaseous product yield. Furthermore, the HCA (Hierarchical Clustering Analysis) employed in the experimental data analysis revealed that the gasification of fuel blends of 20 and 40%w/w of biomass content results in higher volumes of the total gas, hydrogen, carbon monoxide and carbon dioxide than gasification of fuel blends of higher biomass content. - Highlights: • Simulated utilization of HTR excess heat in co-gasification of coal and biomass. • Assessment of three system configurations in terms of hydrogen production. • Application of the HCA in the experimental data set analysis. • Variation in gas components volume and content with fuel blend composition

  17. Catalytic Hydrothermal Gasification of Lignin-Rich Biorefinery Residues and Algae Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Douglas C.; Neuenschwander, Gary G.; Hart, Todd R.; Rotness, Leslie J.; Zacher, Alan H.; Santosa, Daniel M.; Valkenburt, Corinne; Jones, Susanne B.; Tjokro Rahardjo, Sandra A.

    2009-11-03

    This report describes the results of the work performed by PNNL using feedstock materials provided by the National Renewable Energy Laboratory, KL Energy and Lignol lignocellulosic ethanol pilot plants. Test results with algae feedstocks provided by Genifuel, which provided in-kind cost share to the project, are also included. The work conducted during this project involved developing and demonstrating on the bench-scale process technology at PNNL for catalytic hydrothermal gasification of lignin-rich biorefinery residues and algae. A technoeconomic assessment evaluated the use of the technology for energy recovery in a lignocellulosic ethanol plant.

  18. Catalytic extraction processing of contaminated scrap metal

    International Nuclear Information System (INIS)

    The contract was conceived to establish the commercial capability of Catalytic Extraction Processing (CEP) to treat contaminated scrap metal in the DOE inventory. In so doing, Molten Metal Technology, Inc. (MMT), pursued the following objectives: demonstration of the recycling of ferrous and non-ferrous metals--to establish that radioactively contaminated scrap metal can be converted to high-grade, ferrous and non-ferrous alloys which can be reused by DOE or reintroduced into commerce; immobilize radionuclides--that CEP will concentrate the radionuclides in a dense vitreous phase, minimize secondary waste generation and stabilize and reduce waste volume; destroy hazardous organics--that CEP will convert hazardous organics to valuable industrial gases, which can be used as feed gases for chemical synthesis or as an energy source; recovery volatile heavy metals--that CEP's off-gas treatment system will capture volatile heavy metals, such as mercury and lead; and establish that CEP is economical for processing contaminated scrap metal in the DOE inventory--that CEP is a more cost-effective and, complete treatment and recycling technology than competing technologies for processing contaminated scrap. The process and its performance are described

  19. Fuel gas conditioning process

    Science.gov (United States)

    Lokhandwala, Kaaeid A.

    2000-01-01

    A process for conditioning natural gas containing C.sub.3+ hydrocarbons and/or acid gas, so that it can be used as combustion fuel to run gas-powered equipment, including compressors, in the gas field or the gas processing plant. Compared with prior art processes, the invention creates lesser quantities of low-pressure gas per unit volume of fuel gas produced. Optionally, the process can also produce an NGL product.

  20. Experimental study of hydrogen-rich/oxygen-rich gas-gas injectors

    Institute of Scientific and Technical Information of China (English)

    Jin Ping; Li Mao; Cai Guobiao

    2013-01-01

    Five types of coaxial injectors were investigated experimentally using hot hydrogen-rich gas and oxygen-rich gas, which were respectively provided by a GH2/GO2 hydrogen-rich perburner and a GH2/GO2 oxygen-rich preburner. The injectors were the shear coaxial injector, the oxidizer post expansion coaxial injector, the fuel impinging coaxial injector, the central body coaxial injec-tor, and the shear tri-coaxial injector. The characteristic velocity efficiency and the combustor’s wall temperatures were obtained for different design parameters through the experiments. It can be con-cluded that angles of the oxidizer post expansion and the fuel impinging have little influence on the combustion performance and the wall temperatures. The contact area between fuel and oxidizer and the mass flow rate have significant impacts on the combustion performance. The shear tri-coaxial injector has the best combustion performance but also the highest wall temperatures among the five types of injectors.

  1. Advanced catalytic converter system for natural gas powered diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Strots, V.O.; Bunimovich, G.A.; Matros, Y.S. [Matros Technologies Inc., Chesterfield, Missouri (United States); Zheng, M.; Mirosh, E.A. [Alternative Fuel Systems Inc., Calgary, Alberta (Canada)

    1998-12-31

    The paper discusses the development of catalytic converter for aftertreatment of exhaust gas from diesel engines powered with natural gas. The converter, operated with periodical reversals of the flow, ensures destruction of CO and hydrocarbons, including methane. Both computer simulation and engine testing results are presented. 8 refs.

  2. OPERATING SPECIFICATIONS OF CATALYTIC CLEANING OF GAS FROM BIOMASS GASIFICATION

    Directory of Open Access Journals (Sweden)

    Martin Lisý

    2015-12-01

    Full Text Available The paper focuses on the theoretical description of the cleaning of syngas from biomass and waste gasification using catalytic methods, and on the verification of the theory through experiments. The main obstruction to using syngas from fluid gasification of organic matter is the presence of various high-boiling point hydrocarbons (i.e., tar in the gas. The elimination of tar from the gas is a key factor in subsequent use of the gas in other technologies for cogeneration of electrical energy and heat. The application of a natural or artificial catalyst for catalytic destruction of tar is one of the methods of secondary elimination of tar from syngas. In our experiments, we used a natural catalyst (dolomite or calcium magnesium carbonate from Horní Lánov with great mechanical and catalytic properties, suitable for our purposes. The advantages of natural catalysts in contrast to artificial catalysts include their availability, low purchase prices and higher resilience to the so-called catalyst poison. Natural calcium catalysts may also capture undesired compounds of sulphure and chlorine. Our paper presents a theoretical description and analysis of catalytic destruction of tar into combustible gas components, and of the impact of dolomite calcination on its efficiency. The efficiency of the technology is verified in laboratories. The facility used for verification was a 150 kW pilot gasification unit with a laboratory catalytic filter. The efficiency of tar elimination reached 99.5%, the tar concentration complied with limits for use of the gas in combustion engines, and the tar content reached approximately 35 mg/mn3. The results of the measurements conducted in laboratories helped us design a pilot technology for catalytic gas cleaning.

  3. Gas-rich sediment and coastal wetland loss in Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, M.D.; McGinnis, L.D.; Wilkey, P.L.; Miller, S.F.

    1993-03-01

    High rates of wetland loss in southern Louisiana provide the impetus for examining the role that trapped, biogenic gases play in regulating subsidence of coastal areas. A significant cause for wetland loss in this region is relative sea-level rise produced by sediment-volume reduction. Dewatering, grain reorientation and packing, and oxidation of organic-rich sediments are thought to be the main processes for volume loss. It is argued that natural and anthropogenic causes for sediment degasification play a critical role in sediment-volume reduction. Compressional wave velocities were measured at 34 sites in both the abandoned (Holocene) and modern parts of the Mssissippi Delta. A low-frequency source (<200 Hz) was used to maximize sound-wave dispersion caused by interstitial gas bubbles. Compressional wave velocities measured at low frequencies relative to the gas-bubble resonant-frequency undergo maximum change from the velocity for a gas-free sediment.

  4. 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

  5. Gas-Rich Companions of Isolated Galaxies

    CERN Document Server

    Pisano, D J; Wilcots, Eric M.

    1999-01-01

    We have used the VLA to search for gaseous remnants of the galaxy formation process around six extremely isolated galaxies. We found two distinct HI clouds around each of two galaxies in our sample (UGC 9762 & UGC 11124). These clouds are rotating and appear to have optical counterparts, strongly implying that they are typical dwarf galaxies. The companions are currently weakly interacting with the primary galaxy, but have short dynamical friction timescales (~1 Gyr) suggesting that these triple galaxy systems will shortly collapse into one massive galaxy. Given that the companions are consistent with being in circular rotation about the primary galaxy, and that they have small relative masses, the resulting merger will be a minor one. The companions do, however, contain enough gas that the merger will represent a significant infusion of fuel to drive future star formation, bar formation, or central activity, while building up the mass of the disk thus making these systems important pieces of the galaxy f...

  6. Removal of ammonia from producer gas in biomass gasification: integration of gasification optimisation and hot catalytic gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Hongrapipat, Janjira; Saw, Woei-Lean; Pang, Shusheng [University of Canterbury, Department of Chemical and Process Engineering, Christchurch (New Zealand)

    2012-12-15

    Ammonia (NH{sub 3}) is one of the main contaminants in the biomass gasification producer gas, which is undesirable in downstream applications, and thus must be removed. When the producer gas is used in integrated gasification combined cycle (IGCC) technology, NH{sub 3} is the main precursor of nitrogen oxides (NO{sub x}) formed in gas turbine, whereas in Fischer-Tropsch synthesis and in integrated gasification fuel cell (IGFC) technology, the NH{sub 3} gas poisons the catalysts employed. This paper presents a critical review on the recent development in the understanding of the NH{sub 3} formation in biomass gasification process and in the NH{sub 3} gas cleaning technologies. The NH{sub 3} gas concentration in the producer gas can firstly be reduced by the primary measures taken in the gasification process by operation optimisation and using in-bed catalytic materials. Further removal of the NH{sub 3} gas can be implemented by the secondary measures introduced in the post-gasification gas-cleaning process. Focus is given on the catalytic gas cleaning in the secondary measures and its advantages are analysed including energy efficiency, impacts on environment and recyclability of the catalyst. Based on the review, the most effective cleaning process is proposed with integration of both the primary and the secondary measures for application in a biomass gasification process. (orig.)

  7. 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.

  8. The Catalytic Pellet: A Rich Prototype for Engineering Up-Scaling

    Science.gov (United States)

    Arce, Pedro E.; Oyanader, Mario; Whitaker, Stephen

    2007-01-01

    This paper focuses on the use of scaling aspects for understanding transport processes with reaction in catalytic pores and pellets. The idea is to identify a systematic up-scaling approach in the learning process to help students with several concepts related to the transport-reaction process and the mathematical description associated with them.…

  9. Catalytic cracking process with vanadium passivation

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, J.V.; Jossens, L.W.

    1991-03-26

    This paper discusses a process for the catalytic cracking of metal-containing hydrocarbonaceous feedstock. It comprises contacting the feedstock under cracking conditions with a dual component catalyst composition. The catalyst composition comprises a first component comprising an active cracking catalyst; and a second component, as a separate and distinct entity, the second component comprising the following materials: a calcium and magnesium containing material selected from the group consisting of dolomite, substantially amorphous calcium magnesium silicate, calcium magnesium oxide, calcium magnesium acetate, calcium magnesium carbonate, and calcium magnesium subcarbonate; a magnesium containing material comprising a hydrous magnesium silicate; and a binder selected from the group consisting of kaolin, bentonite, montmorillonite, saponite, hectorite, alumina, silica, titania, zirconia, silica-alumina, and combinations thereof.

  10. Development of catalytic gas cleaning in gasification

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P.; Kurkela, E.; Staahlberg, P.; Hepola, J. [VTT Energy, Espoo (Finland)

    1996-12-31

    Gasification gas containing dust can be efficiently purified from tars and ammonia with a nickel monolith catalyst. Temperatures of >900 deg C and a residence time of about 1 s (SV 2 500 1/h) were needed at 5 bar pressure to achieve complete tar decomposition and 80 % ammonia conversion. Catalyst deactivation was not observed during test runs of 100 h. At lower pressures dolomites and limestones can also be applied for tar removal at about 900 deg C temperatures. (orig.) 12 refs.

  11. Gas recovery process

    International Nuclear Information System (INIS)

    In order to decontaminate a gas stream containing radioactive krypton, a preliminary step of removing oxygen and oxides of nitrogen by catalytic reaction with hydrogen is performed. The gas stream is then passed serially through a drier, a carbon dioxide adsorber and a xenon adsorber to remove sequentially water, CO2 and xenon therefrom. The gas exiting the xenon adsorber is passed to a krypton recovery plant wherein krypton is concentrated to a first level in a primary distillation column by contact with a reflux liquid in a packed section of the column. The liquid and vapour collecting at the bottom of the column is passed to a separator in which the liquid is separated from the vapour. The liquid is partially evaporated in a vessel to increase concentration thereof and is brought to a concentration of approximately 90 mole % or greater in a second distillation column thereby enabling efficient storage of a radioactive krypton product. (author)

  12. Natural gas combustion in a catalytic turbulent fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Foka, M.; Chaouki, J.; Guy, C.; Klvana, D. [Ecole Polytechnique de Montreal, Quebec (Canada). Dept. of Chemical Engineering

    1994-12-01

    Catalytic fluidized bed combustion of natural gas is shown to be an emerging technology capable of meeting all environmental constraints as far as nitrogen oxides and carbon monoxide are concerned. This technology uses powder catalysts in the turbulent flow regime where the gas-solid contact is optimal so as to maintain a high combustion efficiency. In fact, the catalytic combustion carried out in both the bubbling and the turbulent regimes at 450-500{sup o}C shows that the turbulent regime is more favorable. A single phase plug flow model with axial dispersion is shown to fit satisfactorily the data obtained at 500{sup o}C where the combustion efficiency is very good. A self-sustained combustion was achieved with a mixture of 4% methane at around 500{sup o}C with a complete conversion of methane and a zero emission of NO{sub x} and CO. (author)

  13. Catalytic extraction processing of contaminated scrap metal

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, T.P.; Johnston, J.E.; Payea, B.M. [Molten Metal Technology, Inc., Waltham, MA (United States)] [and others

    1995-10-01

    The U.S. Department of Energy issued a Planned Research and Development Announcement (PRDA) in 1993, with the objective of identifying unique technologies which could be applied to the most hazardous waste streams at DOE sites. The combination of radioactive contamination with additional contamination by hazardous constituents such as those identified by the Resource Conservation and Recovery Act (RCRA) pose an especially challenging problem. Traditional remediation technologies are increasingly becoming less acceptable to stakeholders and regulators because of the risks they pose to public health and safety. Desirable recycling technologies were described by the DOE as: (1) easily installed, operated, and maintained; (2) exhibiting superior environmental performance; (3) protective of worker and public health and safety; (4) readily acceptable to a wide spectrum of evaluators; and (5) economically feasible. Molten Metal Technology, Inc. (MMT) was awarded a contract as a result of the PRDA initiative to demonstrate the applicability of Catalytic Extraction Processing (CEP), MMT`s proprietary elemental recycling technology, to DOE`s inventory of low level mixed waste. This includes DOE`s inventory of radioactively- and RCRA-contaminated scrap metal and other waste forms expected to be generated by the decontamination and decommissioning (D&D) of DOE sites.

  14. Oxygen transport membrane system and method for transferring heat to catalytic/process reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Sean M.; Kromer, Brian R.; Litwin, Michael M.; Rosen, Lee J.; Christie, Gervase Maxwell; Wilson, Jamie R.; Kosowski, Lawrence W.; Robinson, Charles

    2016-01-19

    A method and apparatus for producing heat used in a synthesis gas production process is provided. The disclosed method and apparatus include a plurality of tubular oxygen transport membrane elements adapted to separate oxygen from an oxygen containing stream contacting the retentate side of the membrane elements. The permeated oxygen is combusted with a hydrogen containing synthesis gas stream contacting the permeate side of the tubular oxygen transport membrane elements thereby generating a reaction product stream and radiant heat. The present method and apparatus also includes at least one catalytic reactor containing a catalyst to promote the steam reforming reaction wherein the catalytic reactor is surrounded by the plurality of tubular oxygen transport membrane elements. The view factor between the catalytic reactor and the plurality of tubular oxygen transport membrane elements radiating heat to the catalytic reactor is greater than or equal to 0.5

  15. A Novel Study of Methane-Rich Gas Reforming to Syngas and Its Kinetics over Semicoke Catalyst

    Directory of Open Access Journals (Sweden)

    Guojie Zhang

    2014-01-01

    Full Text Available A small-size gasification unit is improved through process optimization to simulate industrial United Gas Improvement Company gasification. It finds that the reaction temperature has important impacts on semicoke catalyzed methane gas mixture. The addition of water vapor can enhance the catalytic activity of reforming, which is due to the fact that addition of water vapor not only removes carbon deposit produced in the reforming and gasification reaction processes, but also participates in gasification reaction with semicoke to generate some active oxygen-containing functional groups. The active oxygen-containing functional groups provide active sites for carbon dioxide reforming of methane, promoting the reforming reaction. It also finds that the addition of different proportions of methane-rich gas can yield synthesis gas with different H2/CO ratio. The kinetics study shows that the semicoke can reduce the activation energy of the reforming reaction and promote the occurrence of the reforming reaction. The kinetics model of methane reforming under the conditions of steam gasification over semicoke is as follows: k-=5.02×103·pCH40.71·pH20.26·exp(−74200/RT.

  16. 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.

  17. Biomass to hydrogen-rich syngas via catalytic steam gasification of bio-oil/biochar slurry.

    Science.gov (United States)

    Chen, Guanyi; Yao, Jingang; Liu, Jing; Yan, Beibei; Shan, Rui

    2015-12-01

    The catalytic steam gasification of bio-oil/biochar slurry (bioslurry) for hydrogen-rich syngas production was investigated in a fixed-bed reactor using LaXFeO3 (X=Ce, Mg, K) perovskite-type catalysts. The effects of elemental substitution in LaFeO3, temperature, water to carbon molar ratio (WCMR) and bioslurry weight hourly space velocity (WbHSV) were examined. The results showed that La0.8Ce0.2FeO3 gave the best performance among the prepared catalysts and had better catalytic activity and stability than the commercial 14 wt.% Ni/Al2O3. The deactivation caused by carbon deposition and sintering was significantly depressed in the case of La0.8Ce0.2FeO3 catalyst. Both higher temperature and lower WbHSV contributed to more H2 yield. The optimal WCMR was found to be 2, and excessive introducing of steam reduced hydrogen yield. The La0.8Ce0.2FeO3 catalyst gave a maximum H2 yield of 82.01% with carbon conversion of 65.57% under the optimum operating conditions (temperature=800°C, WCMR=2 and WbHSV=15.36h(-1)). PMID:26378962

  18. Northwestern University Facility for Clean Catalytic Process Research

    Energy Technology Data Exchange (ETDEWEB)

    Marks, Tobin Jay [Northwestern University

    2013-05-08

    Northwestern University with DOE support created a Facility for Clean Catalytic Process Research. This facility is designed to further strengthen our already strong catalysis research capabilities and thus to address these National challenges. Thus, state-of-the art instrumentation and experimentation facility was commissioned to add far greater breadth, depth, and throughput to our ability to invent, test, and understand catalysts and catalytic processes, hence to improve them via knowledge-based design and evaluation approaches.

  19. Catalytic steam gasification of biomass in fluidized bed at low temperature: Conversion from livestock manure compost to hydrogen-rich syngas

    International Nuclear Information System (INIS)

    Utilizing large amounts of animal waste as a source of renewable energy has the potential to reduce its disposal problems and associated pollution issues. Gasification characteristics of the manure compost make it possible for low temperature gasification. In this paper, an energy efficient approach to hydrogen-rich syngas from manure compost is represented at relatively low temperature, around 600 oC, in a continuous-feeding fluidized bed reactor. The effects of catalyst performance, reactor temperature, steam, and reaction type on gas yield, gas composition, and carbon conversion efficiency are discussed. The Ni-Al2O3 catalyst simultaneously promotes tar cracking and steam reforming. Higher temperature contributes to higher gas yield and carbon conversion. The steam introduction increases hydrogen yield, by steam reforming and water-gas shift reaction. Two-stage gasification is also tried, showing the advantage of better catalyst utilization and enhancing the catalytic reactions to some extent.

  20. Quantum-catalytic extraction process application to mixed waste processing

    International Nuclear Information System (INIS)

    The Catalytic Extraction Process (CEP) is a flexible and innovative technology which can process hazardous waste streams in a wide range of chemical and physical forms. The capabilities of CEP technology have been demonstrated on a commercial-scale prototype on RCRA listed hazardous waste streams. The results indicate that CEP can achieve almost 100% recycling of feed to commercially valuable products while maintaining high environmental performance. Specifically, CEP achieves Destruction Removal Efficiencies (DREs) ≥ 99.9999% with no detectable amounts of trace components. Furthermore, any solid products are non-leachable. Quantum-CEPTM, a technology that has evolved from CEP, allows processing of mixed waste streams and preparation for final form disposal. This paper discusses the theoretically achievable and experimentally demonstrated radionuclide partitioning achieved by Quantum-CEP. It also discusses the theoretical foundations and experimental evidence of Quantum-CEP's flexibility to drive partitioning to the desired phase by manipulating operating conditions, hence significantly improving volume reduction. Specifically, this paper focuses on (i) processing contaminated scrap metal and (ii) processing contaminated ion exchange resins using Quantum-CEP. Radionuclide surrogate demonstrations using CEP outlined in this paper indicate decontamination of metal to greater that 99% (limited by the lower detection limit (LDL)) while achieving stabilization of the vitreous phase. Processing of ion exchange resins contaminated with radioactive cobalt and cesium using CEP indicate complete recovery and concentration of the cobalt in the metal phase and condensation and capture of the cesium from the gaseous phase

  1. Pilot-Scale Biorefinery: Sustainable Transport Fuels from Biomass and Algal Residues via Integrated Pyrolysis, Catalytic Hydroconversion and Co-processing with Vacuum Gas Oil

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Olarte, M. V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hart, T. R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-07-21

    Beginning in 2010, UOP, along with the Department of Energy and other project partners, designed a pathway for an integrated biorefinery to process solid biomass into transportation fuel blendstocks. The integrated biorefinery (IBR) would convert second generation feedstocks into pyrolysis oil which would then be upgraded into fuel blendstocks without the limitations of traditional biofuels.

  2. Gas migration regimes and outgassing in particle-rich suspensions

    Directory of Open Access Journals (Sweden)

    Julie eOppenheimer

    2015-08-01

    Full Text Available Understanding how gases escape from particle-rich suspensions has important applications in nature and industry. Motivated by applications such as outgassing of crystal-rich magmas, we map gas migration patterns in experiments where we vary (1 particle fractions and liquid viscosity (10 Pa s – 500 Pa s, (2 container shape (horizontal parallel plates and upright cylinders, and (3 methods of bubble generation (single bubble injections, and multiple bubble generation with chemical reactions. We identify two successive changes in gas migration behavior that are determined by the normalized particle fraction (relative to random close packing, and are insensitive to liquid viscosity, bubble growth rate or container shape within the explored ranges. The first occurs at the random loose packing, when gas bubbles begin to deform; the second occurs near the random close packing, and is characterized by gas migration in a fracture-like manner. We suggest that changes in gas migration behavior are caused by dilation of the granular network, which locally resists bubble growth. The resulting bubble deformation increases the likelihood of bubble coalescence, and promotes the development of permeable pathways at low porosities. This behavior may explain the efficient loss of volatiles from viscous slurries such as crystal-rich magmas.

  3. Emerging catalytic processes for the production of adipic acid

    OpenAIRE

    Van de Vyver, Stijn; Roman, Yuriy

    2012-01-01

    Research efforts to find more sustainable pathways for the synthesis of adipic acid have led to the introduction of new catalytic processes for producing this commodity chemical from alternative resources. With a focus on the performance of oxygen and hydrogen peroxide as preferred oxidants, this minireview summarizes recent advances made in the selective oxidation of cyclohexene, cyclohexane, cyclohexanone and n-hexane to adipic acid. Special attention is paid to the exploration of catalytic...

  4. Gas cleaning and hydrogen sulfide removal for COREX coal gas by sorption enhanced catalytic oxidation over recyclable activated carbon desulfurizer.

    Science.gov (United States)

    Sun, Tonghua; Shen, Yafei; Jia, Jinping

    2014-02-18

    This paper proposes a novel self-developed JTS-01 desulfurizer and JZC-80 alkaline adsorbent for H2S removal and gas cleaning of the COREX coal gas in small-scale and commercial desulfurizing devices. JTS-01 desulfurizer was loaded with metal oxide (i.e., ferric oxides) catalysts on the surface of activated carbons (AC), and the catalyst capacity was improved dramatically by means of ultrasonically assisted impregnation. Consequently, the sulfur saturation capacity and sulfur capacity breakthrough increased by 30.3% and 27.9%, respectively. The whole desulfurizing process combined selective adsorption with catalytic oxidation. Moreover, JZC-80 adsorbent can effectively remove impurities such as HCl, HF, HCN, and ash in the COREX coal gas, stabilizing the system pressure drop. The JTS-01 desulfurizer and JZC-80 adsorbent have been successfully applied for the COREX coal gas cleaning in the commercial plant at Baosteel, Shanghai. The sulfur capacity of JTS-01 desulfurizer can reach more than 50% in industrial applications. Compared with the conventional dry desulfurization process, the modified AC desulfurizers have more merit, especially in terms of the JTS-01 desulfurizer with higher sulfur capacity and low pressure drop. Thus, this sorption enhanced catalytic desulfurization has promising prospects for H2S removal and other gas cleaning. PMID:24456468

  5. Effect of hydrogen on passivation quality of SiNx/Si-rich SiNx stacked layers deposited by catalytic chemical vapor deposition on c-Si wafers

    International Nuclear Information System (INIS)

    We investigate the role of hydrogen content and fixed charges of catalytic chemical vapor deposited (Cat-CVD) SiNx/Si-rich SiNx stacked layers on the quality of crystalline silicon (c-Si) surface passivation. Calculated density of fixed charges is on the order of 1012 cm−2, which is high enough for effective field effect passivation. Hydrogen content in the films is also found to contribute significantly to improvement in passivation quality of the stacked layers. Furthermore, Si-rich SiNx films deposited with H2 dilution show better passivation quality of SiNx/Si-rich SiNx stacked layers than those prepared without H2 dilution. Effective minority carrier lifetime (τeff) in c-Si passivated by SiNx/Si-rich SiNx stacked layers is as high as 5.1 ms when H2 is added during Si-rich SiNx deposition, which is much higher than the case of using Si-rich SiNx films prepared without H2 dilution showing τeff of 3.3 ms. - Highlights: • Passivation mechanism of Si-rich SiNx/SiNx stacked layers is investigated. • H atoms play important role in passivation quality of the stacked layer. • Addition of H2 gas during Si-rich SiNx film deposition greatly enhances effective minority carrier lifetime (τeff). • For a Si-rich SiNx film with refractive index of 2.92, τeff improves from 3.3 to 5.1 ms by H2 addition

  6. Study on Influence to Waste Water Treatment Plant’s Sludge by Low-carbon Catalytic Combustion Furnace of Natural Gas

    OpenAIRE

    Ren TianQi; Fang Kai; Zhang Shihong

    2016-01-01

    There are two parts in this experiment. One of is about the concentration of Variation of exhaust gas while heating sludge of waste water treatment plant. The other one is about introduce the problems of the traditional incineration processes of sludge of waste water treatment as compared between the sludge heated by natural gas catalytic combustion furnace and the tradition’s. We can see that natural gas low-carbon catalytic combustion furnace realize the near-zero emission of contaminates.

  7. Experimental Evaluation of SI Engine Operation Supplemented by Hydrogen Rich Gas from a Compact Plasma Boosted Reformer

    International Nuclear Information System (INIS)

    It is well known that hydrogen addition to spark-ignited (SI) engines can reduce exhaust emissions and increase efficiency. Micro plasmatron fuel converters can be used for onboard generation of hydrogen-rich gas by partial oxidation of a wide range of fuels. These plasma-boosted microreformers are compact, rugged, and provide rapid response. With hydrogen supplement to the main fuel, SI engines can run very lean resulting in a large reduction in nitrogen oxides (NO x ) emissions relative to stoichiometric combustion without a catalytic converter. This paper presents experimental results from a microplasmatron fuel converter operating under variable oxygen to carbon ratios. Tests have also been carried out to evaluate the effect of the addition of a microplasmatron fuel converter generated gas in a 1995 2.3-L four-cylinder SI production engine. The tests were performed with and without hydrogen-rich gas produced by the plasma boosted fuel converter with gasoline. A one hundred fold reduction in NO x due to very lean operation was obtained under certain conditions. An advantage of onboard plasma-boosted generation of hydrogen-rich gas is that it is used only when required and can be readily turned on and off. Substantial NO x reduction should also be obtainable by heavy exhaust gas recirculation (EGR) facilitated by use of hydrogen-rich gas with stoichiometric operation

  8. Emergency gas processing device

    International Nuclear Information System (INIS)

    The present invention provides an emergency gas processing device which discharged contaminated air in a reactor building to the outside. Namely, a suction port of an emergency gas processing pipeline is disposed in the inside of the reactor building. The exit of the pipeline is connected to an exhaustion pipe of the building. On the side of the inlet of the pipeline, there are disposed an inlet valve, an air dryer, a blower, a filter unit and an exit valve from the suction port to the downstream. A heater is disposed to the air dryer. A recycling pipeline equipped with an automatic closing valve for connecting the inlet side of the inlet valve and the inlet side of the exit valve is disposed. Then, the moisture in an emergency gas flown from the inlet valve is removed, heated by the heater, and the temperature of the emergency gas is elevated. Impurities are removed by the filter unit. The automatic closing valve of the recycling pipeline is opened and the blower and the heater are operated to keep the temperature and humidity in the filter unit to a predetermined value during stand-by time. Upon occurrence of an accident, the automatic closing valve is closed, and the aimed system operation is preformed. (I.S.)

  9. Testing marine shales' ability to generate catalytic gas at low temperature

    Science.gov (United States)

    Wei, L.; Schimmelmann, A.; Drobniak, A.; Sauer, P. E.; Mastalerz, M.

    2013-12-01

    Hydrocarbon gases are generally thought to originatevia low-temperature microbial or high-temperature thermogenicpathways (Whiticar, 1996) that can be distinguished by compound-specific hydrogen and carbon stable isotope ratios. An alternative low-temperature catalytic pathway for hydrocarbon generation from sedimentary organic matter has been proposed to be active at temperatures as low as 50oC (e.g.,Mango and Jarvie,2009,2010; Mango et al., 2010; Bartholomew et al., 1999). This hypothesis, however, still requires rigoroustesting by independent laboratory experiments.The possibility of catalytic generation of hydrocarbons in some source rocks (most likely in relatively impermeable and organic-rich shales where reduced catalytic centers can be best preserved) would offer an explanation for the finding of gas of non-microbial origin in formations that lack the thermal maturity for generating thermogenic gas.It is unknown whether catalytically generated methane would be isotopically different from thermogenicmethane (δ13CCH4>-50‰, δ2HCH4from -275‰ to -100‰) ormicrobially generated methane (δ13CCH4from -40‰ to -110‰, δ2HCH4from -400‰to -150‰) (Whiticar, 1998). In order to test for catalytic gas generationin water-wet shales and coals, we are conductinglaboratory experiments at three temperatures (60°C, 100°C, 200°C)and three pressures (ambient pressure, 107 Pa, 3x107 Pa)over periods of six months to several years. So far, our longest running experiments have reached one year. We sealed different types of thermally immature, pre-evacuatedshales (Mowry, New Albany, and Mahoganyshales) and coals (SpringfieldCoal and Wilcoxlignite)with isotopically defined waters in gold cells in the absence of elemental oxygen.Preliminary results show that these samples, depending on conditions, can generate light hydrocarbon gases (methane, ethane and propane) and CO2. Methane, CO2, and traces of H2havebeen generated at 60°C, whereas experiments at 100°C and 200

  10. Selective catalytic reduction system and process using a pre-sulfated zirconia binder

    Science.gov (United States)

    Sobolevskiy, Anatoly; Rossin, Joseph A.

    2010-06-29

    A selective catalytic reduction (SCR) process with a palladium catalyst for reducing NOx in a gas, using hydrogen as a reducing agent is provided. The process comprises contacting the gas stream with a catalyst system, the catalyst system comprising (ZrO.sub.2)SO.sub.4, palladium, and a pre-sulfated zirconia binder. The inclusion of a pre-sulfated zirconia binder substantially increases the durability of a Pd-based SCR catalyst system. A system for implementing the disclosed process is further provided.

  11. 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.

  12. Process gas solidification system

    International Nuclear Information System (INIS)

    A process for withdrawing gaseous UF6 from a first system and directing same into a second system for converting the gas to liquid UF6 at an elevated temperature, additionally including the step of withdrawing the resulting liquid UF6 from the second system, subjecting it to a specified sequence of flash-evaporation, cooling and solidification operations, and storing it as a solid in a plurality of storage vessels. (author)

  13. Simulation for Synthesis of TAME with Catalytic Distillation Process

    Institute of Scientific and Technical Information of China (English)

    Liu Boxue; Deng Zhengyong; Weng Huixin; Gao Buliang

    2008-01-01

    The triangular matrixing modified relaxation model equation was established for the synthesis of TAME with catalytic distillation process, and a new accelerated convergence technique was adopted. The simulation on the synthesis of TAME showed that the calculated data agreed well with the experimental results.

  14. Bacterial catalytic processes for transformation of metals.

    Science.gov (United States)

    Paknikar, K M

    1993-01-01

    Microorganisms actively participate in the transformation of metals and metalloids by various processes including adsorption, absorption, alkylation, oxidation and reduction reactions. Bacteria of the genera Thiobacillus and Sulfolobus have a chemolithotrophic mode of metabolism and catalyze various metal transformations. These bacteria are primarily involved in oxidation-reduction reactions of metals. Metal sulfides can be either directly oxidized by the microbes or oxidized by ferric iron, an end-product of microbial metabolism. These processes result in solubilization of iron, copper, molybdenum, uranium, and many other metals as well. Bacteria capable of these reactions are found, and they function in a variety of environments. Conditions which favor their growth are acidic pH (1.5 to 3.5) and temperatures which can be as high as 75 degrees C for Sulfolobus. The microbes have potential for mobilization of pollutants, or toxic elements, during resource extraction processes. In the absence of oxygen, iron, molybdenum and chromium may be reduced by microbes. PMID:8181951

  15. Gas phase heterogeneous catalytic oxidation of alkanes to aliphatic ketones and/or other oxygenates

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Manhua; Wang, Xiang; Yeom, Younghoon

    2015-09-29

    A catalyst, its method of preparation and its use for producing aliphatic ketones by subjecting alkanes C.sub.3 to C.sub.9 to a gas phase catalytic oxidation in the presence of air or oxygen, and, optionally, steam and/or one or more diluting gases. The catalyst comprises a catalytically active mixed metal oxide phase and a suitable support material onto and/or into which the active catalytic phase is dispersed.

  16. Gas phase heterogeneous catalytic oxidation of alkanes to aliphatic ketones and/or other oxygenates

    Science.gov (United States)

    Lin, Manhua; Wang, Xiang; Yeom, Younghoon

    2015-03-17

    A catalyst, its method of preparation and its use for producing aliphatic ketones by subjecting alkanes C.sub.3 to C.sub.9 to a gas phase catalytic oxidation in the presence of air or oxygen, and, optionally, steam and/or one or more diluting gases. The catalyst comprises a catalytically active mixed metal oxide phase and a suitable support material onto and/or into which the active catalytic phase id dispersed.

  17. Catalytic-Metal/PdO(sub x)/SiC Schottky-Diode Gas Sensors

    Science.gov (United States)

    Hunter, Gary W.; Xu, Jennifer C.; Lukco, Dorothy

    2006-01-01

    Miniaturized hydrogen- and hydrocarbon-gas sensors, heretofore often consisting of Schottky diodes based on catalytic metal in contact with SiC, can be improved by incorporating palladium oxide (PdOx, where 0 less than or equal to x less than or equal to 1) between the catalytic metal and the SiC. In prior such sensors in which the catalytic metal was the alloy PdCr, diffusion and the consequent formation of oxides and silicides of Pd and Cr during operation at high temperature were observed to cause loss of sensitivity. However, it was also observed that any PdOx layers that formed and remained at PdCr/SiC interfaces acted as barriers to diffusion, preventing further deterioration by preventing the subsequent formation of metal silicides. In the present improvement, the lesson learned from these observations is applied by placing PdOx at the catalytic metal/SiC interfaces in a controlled and uniform manner to form stable diffusion barriers that prevent formation of metal silicides. A major advantage of PdOx over other candidate diffusion-barrier materials is that PdOx is a highly stable oxide that can be incorporated into gas sensor structures by use of deposition techniques that are standard in the semiconductor industry. The PdOx layer can be used in a gas sensor structure for improved sensor stability, while maintaining sensitivity. For example, in proof-of-concept experiments, Pt/PdOx/SiC Schottky-diode gas sensors were fabricated and tested. The fabrication process included controlled sputter deposition of PdOx to a thickness of 50 Angstroms on a 400-m-thick SiC substrate, followed by deposition of Pt to a thickness of 450 Angstroms on the PdOx. The SiC substrate (400 microns in thickness) was patterned with photoresist and a Schottky-diode photomask. A lift-off process completed the definition of the Schottky-diode pattern. The sensors were tested by measuring changes in forward currents at a bias potential of 1 V during exposure to H2 in N2 at temperatures

  18. Commercial Test of Flexible Dual-Riser Catalytic Cracking Process

    Institute of Scientific and Technical Information of China (English)

    Tang Haitao; Wang Longyan; Wang Guoliang; Zhang Lixin; Wei Jialu; Chen Zhenghong; Teng Tiancan; Sun Zhonghang

    2003-01-01

    The technical features and commercial test results of flexible dual-riser fluidized catalytic cracking(FDFCC) process are presented for refiners to choose an efficient process to upgrade FCC naphtha and boostpropylene production in a RFCC unit. The commercial test results indicate that the olefin content of catalyti-25% and RON increased by 0.5-2 units in a RFCC unit. In addition, propylene yield and the production ratioof diesel to gasoline can also be remarkably enhanced in the RFCC unit.

  19. Design of Gas-Lift Reactor for Catalytic Oxidation

    Czech Academy of Sciences Publication Activity Database

    Gogová, Zuzana; Hanika, Jiří

    Praha: Process Engineering Publisher, 2008, s. 248. ISBN 978-80-02-02048-6. [18th International Congress of Chemical and Process Engineering CHISA 2008. Praha (CZ), 24.08.2008-28.08.2008] R&D Projects: GA ČR GD203/08/H032 Institutional research plan: CEZ:AV0Z40720504 Keywords : gas- lift reactor * model * glucose Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  20. AGN outflows trigger starbursts in gas-rich galaxies

    CERN Document Server

    Zubovas, Kastytis; King, Andrew; Wilkinson, Mark

    2013-01-01

    Recent well resolved numerical simulations of AGN feedback have shown that its effects on the host galaxy may be not only negative but also positive. In the late gas poor phase, AGN feedback blows the gas away and terminates star formation. However, in the gas-rich phase(s), AGN outflows trigger star formation by over-compressing cold dense gas and thus provide positive feedback on their hosts. In this paper we study this AGN-triggered starburst effect. We show that star formation rate in the burst increases until the star formation feedback counteracts locally the AGN outflow compression. Globally, this predicts a strong nearly linear statistical correlation between the AGN and starburst bolometric luminosities in disc galaxies, L_* \\propto L_{AGN}^{5/6}. The correlation is statistical only because AGN activity may fluctuate on short time scales (as short as tens of years), and because AGN may turn off but its effects on the host may continue to last until the AGN-driven outflow leaves the host, which may be...

  1. Process design for wastewater treatment: catalytic ozonation of organic pollutants.

    Science.gov (United States)

    Derrouiche, S; Bourdin, D; Roche, P; Houssais, B; Machinal, C; Coste, M; Restivo, J; Orfão, J J M; Pereira, M F R; Marco, Y; Garcia-Bordeje, E

    2013-01-01

    Emerging micropollutants have been recently the target of interest for their potential harmful effects in the environment and their resistance to conventional water treatments. Catalytic ozonation is an advanced oxidation process consisting of the formation of highly reactive radicals from the decomposition of ozone promoted by a catalyst. Nanocarbon materials have been shown to be effective catalysts for this process, either in powder form or grown on the surface of a monolithic structure. In this work, carbon nanofibers grown on the surface of a cordierite honeycomb monolith are tested as catalyst for the ozonation of five selected micropollutants: atrazine (ATZ), bezafibrate, erythromycin, metolachlor, and nonylphenol. The process is tested both in laboratorial and real conditions. Later on, ATZ was selected as a target pollutant to further investigate the role of the catalytic material. It is shown that the inclusion of a catalyst improves the mineralization degree compared to single ozonation. PMID:24056437

  2. Selective CO oxidation in hydrogen-rich gas over CuO/CeO2 catalysts

    International Nuclear Information System (INIS)

    A series of CuO/CeO2 catalysts with different Cu-Ce compositions were synthesized by co-precipitation method and characterized by X-ray diffraction, H2-TPR, CO-TPD, SEM and X-ray photoelectron spectroscopy (XPS) techniques. The effects of Cu-Ce composition and water vapor on the catalytic properties for the selective CO oxidation in the hydrogen-rich gas were investigated. The results indicated that CuO (10%)/CeO2 catalyst remained the maximum CO conversion and selectivity at 140 and 160 deg. C, while the performance of CuO/CeO2 catalysts deteriorated with the CuO molar ratio further increased. The interfacial CuO and CeO2 interaction and synergistic effect enhanced the redox properties of CuO/CeO2 catalyst and the highly dispersed copper species were proposed as the active sites for the selective CO oxidation. The blockage of catalytic active sites by absorbed water and the formation of CO-H2O surface complexes reduced the activity of CuO (10%)/CeO2 catalyst. The decreasing of surface lattice oxygen and absorbed oxygen species and the agglomeration of copper particles were the plausible interpretations for the deactivation of CuO (10%)/CeO2 catalyst

  3. Design and Experimentation with Sandwich Microstructure for Catalytic Combustion-Type Gas Sensors

    OpenAIRE

    Jun-Tao Gu; Yong-De Zhang; Jin-Gang Jiang

    2014-01-01

    The traditional handmade catalytic combustion gas sensor has some problems such as a pairing difficulty, poor consistency, high power consumption, and not being interchangeable. To address these issues, integrated double catalytic combustion of alcohol gas sensor was designed and manufactured using silicon micro-electro-mechanical systems (MEMS) technology. The temperature field of the sensor is analyzed using the ANSYS finite element analysis method. In this work, the silicon oxide-PECVD-oxi...

  4. 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

  5. Catalytic pleat filter bags for combined particulate separation and nitrogen oxides removal from flue gas streams

    International Nuclear Information System (INIS)

    The development of a high temperature catalytically active pleated filter bag with hybrid filter equipment for the combined removal of particles and nitrogen oxides from flue gas streams is presented. A special catalyst load in stainless steel mesh cartridge with a high temperature pleated filter bag followed by optimized catalytic activation was developed to reach the required nitrogen oxides levels and to maintain the higher collection efficiencies. The catalytic properties of the developed high temperature filter bags with hybrid filter equipment were studied and demonstrated in a pilot scale test rig and a demonstration plant using commercial scale of high temperature catalytic pleated filter bags. The performance of the catalytic pleated filter bags were tested under different operating conditions, such as filtration velocity and operating temperature. Moreover, the cleaning efficiency and residual pressure drop of the catalyst loaded cartridges in pleated filter bags were tested. As result of theses studies, the optimum operating conditions for the catalytic pleated filter bags are determined. (author)

  6. Novel test of modified Newtonian dynamics with gas rich galaxies.

    Science.gov (United States)

    McGaugh, Stacy S

    2011-03-25

    The current cosmological paradigm, the cold dark matter model with a cosmological constant, requires that the mass-energy of the Universe be dominated by invisible components: dark matter and dark energy. An alternative to these dark components is that the law of gravity be modified on the relevant scales. A test of these ideas is provided by the baryonic Tully-Fisher relation (BTFR), an empirical relation between the observed mass of a galaxy and its rotation velocity. Here, I report a test using gas rich galaxies for which both axes of the BTFR can be measured independently of the theories being tested and without the systematic uncertainty in stellar mass that affects the same test with star dominated spirals. The data fall precisely where predicted a priori by the modified Newtonian dynamics. The scatter in the BTFR is attributable entirely to observational uncertainty, consistent with a single effective force law. PMID:21517295

  7. Fiber-supported perovskites for catalytic combustion of natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Klvana, D.; Kirchnerova, J.; Chaouki, J.; Delval, J. [Department of Chemical Engineering, Ecole Polytechnique, PO Box 6079, Station Centre-Ville, Montreal (Canada); Yaieci, W. [Centre des technologies du gaz naturel, 1350, rue Nobel, Boucherville (Canada)

    1999-01-01

    Based on previous work, highly performing combustion catalyst consisting of an iron doped nickel-cobalt-based perovskite supported on commercial fiber blankets has been developed. The catalyst is particularly suitable for use in combustion of lean natural gas mixtures. With 12-15wt% perovskite loadings the catalyst exhibits activities comparable to those of commercial fiber-supported platinum. At temperatures below 1000K the catalyst activity seems stable, and resistant to low levels of mercaptan used as an odorant. Unlike platinum (or palladium) the catalyst promotes deep methane oxidation, i.e. no carbon monoxide formation, even in methane-rich mixtures. The combustion is inhibited by carbon dioxide, but water has no measurable influence. A simple kinetic model which takes the inhibition effect of carbon dioxide into account and permits more realistic conversion estimates is proposed: r{sub CO{sub 2}}=k{sub CH{sub 4}}P{sub CH{sub 4}}/(1+k{sub CO{sub 2}}P{sub CO{sub 2}})

  8. Selective catalytic reduction system and process for treating NOx emissions using a palladium and rhodium or ruthenium catalyst

    Science.gov (United States)

    Sobolevskiy, Anatoly; Rossin, Joseph A.; Knapke, Michael J.

    2011-07-12

    A process for the catalytic reduction of nitrogen oxides (NOx) in a gas stream (29) in the presence of H.sub.2 is provided. The process comprises contacting the gas stream with a catalyst system (38) comprising zirconia-silica washcoat particles (41), a pre-sulfated zirconia binder (44), and a catalyst combination (40) comprising palladium and at least one of rhodium, ruthenium, or a mixture of ruthenium and rhodium.

  9. Catalytic and surface oxidation processes on transition metal surfaces

    OpenAIRE

    Jaatinen, Sampsa

    2007-01-01

    Transition metals are technologically important catalytic materials. The transition metal catalysts are used for example in petroleum and fertilizer industry. In the car industry the catalytic materials are used in the catalytic converters. Because of the industrial importance the catalytic metals have been widely studied throughout the past decades. Nonetheless, the oxidation mechanisms of small molecules and the effect of alloying to catalytic properties of metals are not fully understood. ...

  10. Catalytic process for control of NO.sub.x emissions using hydrogen

    Science.gov (United States)

    Sobolevskiy, Anatoly; Rossin, Joseph A.; Knapke, Michael J.

    2010-05-18

    A selective catalytic reduction process with a palladium catalyst for reducing NOx in a gas, using hydrogen as a reducing agent. A zirconium sulfate (ZrO.sub.2)SO.sub.4 catalyst support material with about 0.01-2.0 wt. % Pd is applied to a catalytic bed positioned in a flow of exhaust gas at about 70-200.degree. C. The support material may be (ZrO.sub.2--SiO.sub.2)SO.sub.4. H.sub.2O and hydrogen may be injected into the exhaust gas upstream of the catalyst to a concentration of about 15-23 vol. % H.sub.2O and a molar ratio for H.sub.2/NO.sub.x in the range of 10-100. A hydrogen-containing fuel may be synthesized in an Integrated Gasification Combined Cycle power plant for combustion in a gas turbine to produce the exhaust gas flow. A portion of the fuel may be diverted for the hydrogen injection.

  11. Catalytic Cracking of Triglyceride-Rich Biomass toward Lower Olefins over a Nano-ZSM-5/SBA-15 Analog Composite

    Directory of Open Access Journals (Sweden)

    Xuan Hoan Vu

    2015-10-01

    Full Text Available The catalytic cracking of triglyceride-rich biomass toward C2–C4 olefins was evaluated over a hierarchically textured nano-ZSM-5/SBA-15 analog composite (ZSC-24 under fluid catalytic cracking (FCC conditions. The experiments were performed on a fully automated Single-Receiver Short-Contact-Time Microactivity Test unit (SR-SCT-MAT, Grace Davison at 550 °C and different catalyst-to-oil mass ratios (0–1.2 g∙g−1. The ZSC-24 catalyst is very effective for transformation of triglycerides to valuable hydrocarbons, particularly lower olefins. The selectivity to C2–C4 olefins is remarkably high (>90% throughout the investigated catalyst-to-oil ratio range. The superior catalytic performance of the ZSC-24 catalyst can be attributed to the combination of its medium acid site amount and improved molecular transport provided by the bimodal pore system, which effectively suppresses the secondary reactions of primarily formed lower olefins.

  12. Catalytic arylation methods from the academic lab to industrial processes

    CERN Document Server

    Burke, Anthony J

    2014-01-01

    A current view of the challenging field of catalytic arylation reactions. Clearly structured, the chapters in this one-stop resource are arranged according to the reaction type, and focus on novel, efficient and sustainable processes, rather than the well-known and established cross-coupling methods.The entire contents are written by two authors with academic and industrial expertise to ensure consistent coverage of the latest developments in the field, as well as industrial applications, such as C-H activation, iron and gold-catalyzed coupling reactions, cycloadditions or novel methodologies

  13. 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.

  14. Development and test of a new catalytic converter for natural gas fuelled engine

    Indian Academy of Sciences (India)

    M A Kalam; H H Masjuki; M Redzuan; T M I Mahlia; M A Fuad; M Mohibah; K H Halim; A Ishak; M Khair; A Shahrir; A Yusoff

    2009-06-01

    This paper presents characteristics of a new catalytic converter (catco) to be used for natural gas fuelled engine. The catco were developed based on catalyst materials consisting of metal oxides such as titanium dioxide (TiO2) and cobalt oxide (CoO) with wire mesh substrate. Both of the catalyst materials (such as TiO2 and CoO) are inexpensive in comparison with conventional catalysts (noble metals) such as palladium or platinum. In addition, the noble metals such as platinum group metals are now identified as human health risk due to their rapid emissions in the environment from various resources like conventional catalytic converter, jewelers and other medical usages. It can be mentioned that the TiO2/CoO based catalytic converter and a new natural gas engine such as compressed natural gas (CNG) direct injection (DI) engine were developed under a research collaboration program. The original engine manufacture catalytic conveter (OEM catco) was tested for comparison purposes. The OEM catco was based on noble metal catalyst with honeycomb ceramic substrate. It is experimentally found that the conversion efficiencies of TiO2/CoO based catalytic converter are 93%, 89% and 82% for NOx, CO and HC emissions respectively. It is calculated that the TiO2/CoO based catalytic converter reduces 24%, 41% and 40% higher NOx, CO and HC emissions in comparison to OEM catco respectively. The objective of this paper is to develop a low-cost three way catalytic converter to be used with the newly developed CNG-DI engine. Detailed review on catalytic converter, low-cost catalytic converter development characteristics and CNGDI engine test results have been presented with discussions.

  15. Kinetic and Phase Behaviors of Catalytic Cracking Dry Gas Hydrate in Water-in-Oil Emulsion

    Institute of Scientific and Technical Information of China (English)

    MA Qinglan; HUANG Qiang; CHEN Guangjin; WANG Xiulin; SUN Changyu; YANG Lanying

    2013-01-01

    The systematic experimental studies were performed on the hydrate formation kinetics and gas-hydrate equilibrium for a simulated catalytic cracking gas in the water-in-oil emulsion.The effect of temperature,pressure and initial gas-liquid ratio on the hydrate formation was studied,respectively.The data were obtained at pressures ranging from 3.5 to 5 MPa and temperatures from 274.15 to 277.15 K.The results showed that hydrogen and methane can be separated from the C2+ fraction by forming hydrate at around 273.15 K which is much higher temperature than that of the cryogenic separation method,and the hydrate formation rate can be enhanced in the water-in-oil emulsion compared to pure water.The experiments provided the basic data for designing the industrial process,and setting the suitable operational conditions.The measured data of gas-hydrate equilibria were compared with the predictions by using the Chen-Guo hydrate thermodynamic model.

  16. 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...

  17. Some problems in adsorption and calorimetric studies of the steps of catalytic processes

    Institute of Scientific and Technical Information of China (English)

    Victor E. Ostrovskii

    2004-01-01

    Principal side factors as well as technical and procedural peculiarities capable of distorting the results of measurements of adsorbed and desorbed amounts, of falsifying the nature of the processes proceeding in the systems under study, and of promoting artifacts in calorimetric and other studies of gas chemisorption on powders are considered. Modified techniques and procedures allowing the elimination of sources of side phenomena and artifacts and freeing traditional glass static adsorption apparatuses and experimental procedures from undesirable factors and peculiarities are proposed.Some available chemisorption and calorimetric data representing artifacts and also some data that are not artifacts but,due to imperfections of chemisorption techniques, show up as artifacts are presented and discussed. Several applications of the improved techniques and procedures to calorimetric and adsorption studies of the steps of catalytic processes proceeding on the basis of natural gas and of products of its processing are presented and discussed.

  18. Catalytic processes towards the production of biofuels in a palm oil and oil palm biomass-based biorefinery.

    Science.gov (United States)

    Chew, Thiam Leng; Bhatia, Subhash

    2008-11-01

    In Malaysia, there has been interest in the utilization of palm oil and oil palm biomass for the production of environmental friendly biofuels. A biorefinery based on palm oil and oil palm biomass for the production of biofuels has been proposed. The catalytic technology plays major role in the different processing stages in a biorefinery for the production of liquid as well as gaseous biofuels. There are number of challenges to find suitable catalytic technology to be used in a typical biorefinery. These challenges include (1) economic barriers, (2) catalysts that facilitate highly selective conversion of substrate to desired products and (3) the issues related to design, operation and control of catalytic reactor. Therefore, the catalytic technology is one of the critical factors that control the successful operation of biorefinery. There are number of catalytic processes in a biorefinery which convert the renewable feedstocks into the desired biofuels. These include biodiesel production from palm oil, catalytic cracking of palm oil for the production of biofuels, the production of hydrogen as well as syngas from biomass gasification, Fischer-Tropsch synthesis (FTS) for the conversion of syngas into liquid fuels and upgrading of liquid/gas fuels obtained from liquefaction/pyrolysis of biomass. The selection of catalysts for these processes is essential in determining the product distribution (olefins, paraffins and oxygenated products). The integration of catalytic technology with compatible separation processes is a key challenge for biorefinery operation from the economic point of view. This paper focuses on different types of catalysts and their role in the catalytic processes for the production of biofuels in a typical palm oil and oil palm biomass-based biorefinery. PMID:18434141

  19. Study on Influence to Waste Water Treatment Plant’s Sludge by Low-carbon Catalytic Combustion Furnace of Natural Gas

    Directory of Open Access Journals (Sweden)

    Ren TianQi

    2016-01-01

    Full Text Available There are two parts in this experiment. One of is about the concentration of Variation of exhaust gas while heating sludge of waste water treatment plant. The other one is about introduce the problems of the traditional incineration processes of sludge of waste water treatment as compared between the sludge heated by natural gas catalytic combustion furnace and the tradition’s. We can see that natural gas low-carbon catalytic combustion furnace realize the near-zero emission of contaminates.

  20. Electrolytic trapping of iodine from process gas streams

    International Nuclear Information System (INIS)

    A method for removing molecular, inorganic, and organic forms of iodine from process gas streams comprises the electrolytic oxidation of iodine in the presence of cobalt-III ions. The gas stream is passed through the anode compartment of a partitioned electrolytic cell having a nitric acid anolyte containing a catalytic amount of cobalt to cause the oxidation of effluent iodine species to aqueous soluble species

  1. A Technical and Economical Evaluation of CO2 Capture from Fluidized Catalytic Cracking (FCC Flue Gas

    Directory of Open Access Journals (Sweden)

    Digne Romina

    2014-11-01

    Full Text Available Environmental issues, related to greenhouse gas and among them CO2, are becoming short term challenges. Pressure on industries and therefore on refining to limit and manage CO2 emissions will be reinforced in next few years. Refining industry is responsible for about 2.7% of global CO2 emissions. Fluidized Catalytic Cracking unit (FCC, one of the main process in refining, represents by itself 20% of the refinery CO2 emissions. As FCC unit is present in half of the refining schemes, it is challenging to find technologies to manage its emissions. Based on an industrial case, the aims of the presented work are to determine if amine technology HiCapt+, developed for power plant, might be a relevant solution to manage FCC CO2 emissions and to evaluate the additional cost to be supported by refiners.

  2. A Technical and Economical Evaluation of CO2 Capture from Fluidized Catalytic Cracking (FCC) Flue Gas

    International Nuclear Information System (INIS)

    Environmental issues, related to greenhouse gas and among them CO2, are becoming short term challenges. Pressure on industries and therefore on refining to limit and manage CO2 emissions will be reinforced in next few years. Refining industry is responsible for about 2.7% of global CO2 emissions. Fluidized Catalytic Cracking unit (FCC), one of the main process in refining, represents by itself 20% of the refinery CO2 emissions. As FCC unit is present in half of the refining schemes, it is challenging to find technologies to manage its emissions. Based on an industrial case, the aims of the presented work are to determine if amine technology HiCapt+, developed for power plant, might be a relevant solution to manage FCC CO2 emissions and to evaluate the additional cost to be supported by refiners. (authors)

  3. A feasibility study on the industialization of catalytic process in connection with domestic chemical plants

    International Nuclear Information System (INIS)

    The technical and economical feasibility on the polymer catalytic process for the production of heavy water in corporating domestic hydrogen reforming plants (RHEX) were performed. It was suggested to run the RHEX process as a closed system to reduce the loss of concentrated deuterium. As a part of solution to this problem the method of recycling methane gas out of the process and of purifying the water from the hydrogen reforming process have been considered. The controlling factor affecting the unit production cost depends on the cost of polymer catalyst rather than the investment cost. If the catalyst would be produced with the suitable price, the proposed process could be quite competitive comparing with other heavy water production processes. (Author)

  4. Definition of a Thermodynamic Parameter to Calculate Carbon Dioxide Emissions in a Catalytic Reforming Process

    Directory of Open Access Journals (Sweden)

    Marie-Noëlle Pons

    2008-06-01

    Full Text Available In the context of global warming, reduction of carbon dioxide emissions in oil and gas processes is an environmental and financial issue for process design and comparison. Environmental impact of a system can be determined by life cycle assessment (LCA. However this method presents limitations. Exergy is a thermodynamic function often chosen to complete LCA as it enables quantifying energetic efficiency of a process and takes into account the relation between the considered process and its environment. The aim of this work is to build a correlation between CO2 emissions and a thermodynamic quantity which depends on exergy. For the process under consideration, this correlation has the following asset: it enables CO2 emissions calculation without performing an LCA, when operating conditions are modified. The process studied here is naphtha catalytic reforming.

  5. Spiral galaxies in clusters. III. Gas-rich galaxies in the Pegasus I cluster of galaxies

    International Nuclear Information System (INIS)

    We report the results of a 21-cm and optical survey of disk galaxies in the vicinity of the Pegasus I cluster of galaxies. The color--gas content relation [log(M/sub H//L/sub B/) vs (B-V)/sup T/0 ] for this particular cluster reveals the presence of a substantial number of blue, gas-rich galaxies. With few exceptions, the disk systems in Pegasus I retain large amounts of neutral hydrogen despite their presence in a cluster. This directly shows that environmental processes have not yet removed substantial amounts of gas from these disk galaxies. We conclude that the environment has had little or no observable effect upon the evolution of disk galaxies in Pegasus I. The overall properties of the Pegasus I spirals are consistent with the suggestion that this cluster is now at an early stage in its evolution

  6. Rapid catalytic processes in reforming of methane and successive synthesis of methanol and its derivatives

    Science.gov (United States)

    Inui, Tomoyuki

    1997-11-01

    In order to obtain high quality fuels and basic raw materials for petrochemical industries, novel catalysts which enable the realization of new synthetic routes have been investigated. First, a highly active Rh-modified Ni-based composite catalyst, NiCe 2O 3PtRh, supported on a ceramic fiber in a plate shape was developed, which reformed methane into the syngas having an appropriate ratio of H2/CO. Furthermore, more combustible ethane or propane was added into the reaction gas and its catalytic combustion was allowed to occur on the same catalyst. The combustion heat compensated the reforming heat resulting in an extraordinarily high space-time yield of hydrogen, as high as 10,000 mol/1·h, even under the condition of a very short contact time, 5 ms, and a very low furnace temperature at around 400°C. Next, a highly active catalyst for methanol synthesis from CO 2-rich or CO-rich syngases was developed. A Cu-based CuZnCrAlGa mixed oxide catalyst was prepared by the uniform gelation method and it was mixed with Pd supported on χ-alumina. The composite catalyst exhibited a much higher activity than the conventional catalyst prepared by the precipitation method and a space-time yield of methanol of 1,300 and 6,730 g/l·h was amounted, respectively, from CO 2-rich and CO-rich syngases under 80 atm and at 270°C. Finally, the products obtained as mentioned above were introduced into the reactor, which was connected in series and the methanol was totally converted into hydrocarbons. In the case of a HGa-silicate catalyst, gasoline was obtained at as high a value as 1,860 g/l·h in space-time yield, and in the case of SAPO-34, ethylene and propylene were obtained with an equivalent selectivity.

  7. Comprehensive Utilization of Biomass Process Residues Rich in Cellulose

    Science.gov (United States)

    Zhong, Mei; Li, Qiang; Yu, Jian; Dong, Li; Wang, Yin; Xu, Guangwen

    2010-11-01

    This article investigated the method preparing porous material (PM) with VL and SL. Applications of the prepared material was tested in removal aqueous phenol and COD in tarry water and as the catalyst support for selective catalytic reduction (SCR) of NO in flue gas. The results showed that the optimal activation condition in CO2 for the carbonized VL at 800° C was at 875° C for 1 h, which provided large BET surface area and micropore volume. This material exhibited the highest adsorption to aqueous phenol among all the tested materials including a commercial activated carbon made from coconut shell, showing the potential application of the VL-base porous material in wastewater treatment. The study demonstrated also that the vanadium-base selective catalytic reduction (SCR) catalyst supported on the VL-base porous material (V2O5/VL-PM) provided fairly good activity as well SO2 resistance at temperatures round 200° C for SCR of NO. The activation of the carbonized SL material in H2O was better than that in CO2 for developing the pore structure of the porous material. Steam can improve the formation of mesopore than CO2. This was confirmed by the conclusion that higher COD removal rate was occurred on the PM-1 from SL when H2O was used as an activator.

  8. HRI catalytic two-stage liquefaction (CTSL) process materials: chemical analysis and biological testing

    Energy Technology Data Exchange (ETDEWEB)

    Wright, C.W.; Later, D.W.

    1985-12-01

    This report presents data from the chemical analysis and biological testing of coal liquefaction materials obtained from the Hydrocarbon Research, Incorporated (HRI) catalytic two-stage liquefaction (CTSL) process. Materials from both an experimental run and a 25-day demonstration run were analyzed. Chemical methods of analysis included adsorption column chromatography, high-resolution gas chromatography, gas chromatography/mass spectrometry, low-voltage probe-inlet mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The biological activity was evaluated using the standard microbial mutagenicity assay and an initiation/promotion assay for mouse-skin tumorigenicity. Where applicable, the results obtained from the analyses of the CTSL materials have been compared to those obtained from the integrated and nonintegrated two-stage coal liquefaction processes. 18 refs., 26 figs., 22 tabs.

  9. Measurements of Gasification Characteristics of Coal and Char in CO2-Rich Gas Flow by TG-DTA

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2013-01-01

    Full Text Available Pyrolysis, combustion, and gasification properties of pulverized coal and char in CO2-rich gas flow were investigated by using gravimetric-differential thermal analysis (TG-DTA with changing O2%, heating temperature gradient, and flow rate of CO2-rich gases provided. Together with TG-DTA, flue gas generated from the heated coal, such as CO, CO2, and hydrocarbons (HCs, was analyzed simultaneously on the heating process. The optimum O2% in CO2-rich gas for combustion and gasification of coal or char was discussed by analyzing flue gas with changing O2 from 0 to 5%. The experimental results indicate that O2% has an especially large effect on carbon oxidation at temperature less than 1100°C, and lower O2 concentration promotes gasification reaction by producing CO gas over 1100°C in temperature. The TG-DTA results with gas analyses have presented basic reference data that show the effects of O2 concentration and heating rate on coal physical and chemical behaviors for the expected technologies on coal gasification in CO2-rich gas and oxygen combustion and underground coal gasification.

  10. Processing of exhaust gas

    International Nuclear Information System (INIS)

    Silicon carbide is an important component in exhaust gas filters for diesel engines. Norway produces and refines SiC, which is used in fireproof and ceramic industry and as an abrasive. It is also increasingly used in electronic industry. The emission from diesel engines consists of small spherical soot particles with an appendage of fuel, lubricating oil, water and sulphur compounds. These particles are intercepted by silicon carbide filters. There is a world-wide demand for environmentally friendly diesel engines and a growing demand for silicon carbide. From 2002, the EU permits a maximum emission of 0.025 grams per km of driving

  11. Wet flue gas desulfurization processes

    Directory of Open Access Journals (Sweden)

    Hayrunnisa Çavuşoğlu

    2013-04-01

    Full Text Available The wet flue gas desulfurization process is widely used for the treatment of exhaust gases in power stations. Due to its high level of effectiveness over the already available processes, it has also been the mostly preferred method by industry. Its high SO2 removal efficiency, wide applicability of absorption chemicals and the ease of the chemical process handling which does not require comprehensive konowledge are among the main advantages of this process. In this article, various wet flue gas desulfurization processes such as lime/limestone have beendiscussed.

  12. Effects of Particle Size on the Gas Sensitivity and Catalytic Activity of In2O3

    Science.gov (United States)

    Zhang, Xiaoshui; Gu, Ruiqin; Zhao, Jinling; Jin, Guixin; Zhao, Mengke; Xue, Yongliang

    2015-10-01

    Nanosized In2O3 powders with different particle sizes were prepared by the microemulsion synthetic method. The effects of particle size on the gas-sensing and catalytic properties of the as-prepared In2O3 were investigated. Reductions in particle size to nanometer levels improved the sensitivity and catalytic activity of In2O3 to i-C4H10 and C2H5OH. The sensitivity of nanosized In2O3 (<42 nm) sensors to i-C4H10, H2 and C2H5OH was 2-4 times higher than that of chemically precipitated In2O3 (130 nm) sensor. A nearly linear relationship was observed between the catalytic activity and specific surface area of In2O3 for the oxidation of i-C4H10 and C2H5OH at 275 °C. The relationship between gas sensitivity and catalytic activity was further discussed. The results of this work reveal that catalytic activity plays a key role in enhancing the sensitivity of gas-sensing materials.

  13. Conceptual design analysis of a collection and processing system for scrapped catalytic converters

    OpenAIRE

    Kuczka, Allan Anthony

    1991-01-01

    The systems engineering process has been applied to develop and evaluate a system that collects and processes scrapped catalytic converters to recover the platinum group metals retained by the converters' spent catalyst substrate. A needs analysis establishes a catalytic converter manufacturer's desire to reduce the cost of obtaining platinum group metals used to produce new catalytic converters. The analysis proposes a collection and processing system as an alternati...

  14. Integrated Process for the Catalytic Conversion of Biomass-Derived Syngas into Transportation Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lebarbier, Vanessa M.; Smith, Colin D.; Flake, Matthew D.; Albrecht, Karl O.; Gray, Michel J.; Ramasamy, Karthikeyan K.; Dagle, Robert A.

    2016-04-19

    Efficient synthesis of renewable fuels that will enable cost competitiveness with petroleum-derived fuels remains a grand challenge for U.S. scientists. In this paper, we report on an integrated catalytic approach for producing transportation fuels from biomass-derived syngas. The composition of the resulting hydrocarbon fuel can be modulated to meet specified requirements. Biomass-derived syngas is first converted over an Rh-based catalyst into a complex aqueous mixture of condensable C2+ oxygenated compounds (predominantly ethanol, acetic acid, acetaldehyde, ethyl acetate). This multi-component aqueous mixture then is fed to a second reactor loaded with a ZnxZryOz mixed oxide catalyst, which has tailored acid-base sites, to produce an olefin mixture rich in isobutene. The olefins then are oligomerized using a solid acid catalyst (e.g., Amberlyst-36) to form condensable olefins with molecular weights that can be targeted for gasoline, jet, and/or diesel fuel applications. The product rich in long-chain olefins (C7+) is finally sent to a fourth reactor that is needed for hydrogenation of the olefins into paraffin fuels. Simulated distillation of the hydrotreated oligomerized liquid product indicates that ~75% of the hydrocarbons present are in the jet-fuel range. Process optimization for the oligomerization step could further improve yield to the jet-fuel range. All of these catalytic steps have been demonstrated in sequence, thus providing proof-of-concept for a new integrated process for the production of drop-in biofuels. This unique and flexible process does not require external hydrogen and also could be applied to non-syngas derived feedstock, such as fermentation products (e.g., ethanol, acetic acid, etc.), other oxygenates, and mixtures thereof containing alcohols, acids, aldehydes and/or esters.

  15. Rapid gas hydrate formation process

    Science.gov (United States)

    Brown, Thomas D.; Taylor, Charles E.; Unione, Alfred J.

    2013-01-15

    The disclosure provides a method and apparatus for forming gas hydrates from a two-phase mixture of water and a hydrate forming gas. The two-phase mixture is created in a mixing zone which may be wholly included within the body of a spray nozzle. The two-phase mixture is subsequently sprayed into a reaction zone, where the reaction zone is under pressure and temperature conditions suitable for formation of the gas hydrate. The reaction zone pressure is less than the mixing zone pressure so that expansion of the hydrate-forming gas in the mixture provides a degree of cooling by the Joule-Thompson effect and provides more intimate mixing between the water and the hydrate-forming gas. The result of the process is the formation of gas hydrates continuously and with a greatly reduced induction time. An apparatus for conduct of the method is further provided.

  16. Analysis of the photo catalytic degradation of the 4-chloro phenol and endosulfan by gas chromatography

    International Nuclear Information System (INIS)

    The water and soil pollution by organic compounds of considerable toxicity, is every time more alarming. The phenols and organo chlorinated compounds are some of the pollutants of more environmental concern. The present work shows the degradation by heterogeneous photo catalysis of the 4-chloro phenol and endosulfan in watery solutions using a photo reactor at laboratory scale, under ultraviolet irradiation as energy source and titanium dioxide TiO2 Degussa P25 as catalyst. Solutions of both compounds at concentrations of 10, 20, 30 and 40 mg/L were used, analyzing the more important operation parameters with those that the maxima degradation levels were reached. The analyzed variables were catalyst concentration and irradiation time, the analytical techniques of ultraviolet-visible spectroscopy and gas chromatography were used as process control. By means of ultraviolet-visible spectroscopy it was settled down that starting from the quantitative analysis, the 4-chloro phenol presented bigger degradation at smaller concentrations. Under the operation conditions mentioned in this work, it was observed that the photo catalytic processes obey a first order behavior in the chemical kinetics being adjusted to the Langmuir-Hinshelwood model (L-H). With the purpose of checking the degradation of the same ones it was used the gas chromatography, which is an advanced technique for the process pursuit, auxiliary in the quantification and analysis of the photo catalytic degradation of the 4-chloro phenol and endosulfan. It was based on the development and validation of the analytical method, by means of which was proven that the method is good and reliable in the research environment. The results of the quantitative analysis by gas chromatography and ultraviolet-visible, derived of the photo catalytic degradation of the 4-chloro phenol, in the maximum time of study (180 minutes), using the concentrations of 10, 20, 30 and 40 mg/L was found, by gas chromatography, a maximum

  17. Production of phenol-rich bio-oil during catalytic fixed-bed and microwave pyrolysis of palm kernel shell.

    Science.gov (United States)

    Omoriyekomwan, Joy Esohe; Tahmasebi, Arash; Yu, Jianglong

    2016-05-01

    Catalytic fixed-bed and microwave pyrolysis of palm kernel shell using activated carbon (AC) and lignite char (LC) as catalysts and microwave receptors are investigated. The effects of process parameters including temperature and biomass:catalyst ratio on the yield and composition of pyrolysis products were studied. The addition of catalyst increased the bio-oil yield, but decreased the selectivity of phenol in fixed-bed. Catalytic microwave pyrolysis of PKS significantly enhanced the selectivity of phenol production. The highest concentration of phenol in bio-oil of 64.58 %(area) and total phenolics concentration of 71.24 %(area) were obtained at 500°C using AC. Fourier transform infrared spectroscopy (FTIR) results indicated that concentration of OH, CH, CO and CO functional groups in char samples decreased after pyrolysis. Scanning electron microscopy (SEM) analysis clearly indicated the development of liquid phase in biomass particles during microwave pyrolysis, and the mechanism is also discussed. PMID:26890793

  18. The conversion of anaerobic digestion waste into biofuels via a novel Thermo-Catalytic Reforming process.

    Science.gov (United States)

    Neumann, Johannes; Meyer, Johannes; Ouadi, Miloud; Apfelbacher, Andreas; Binder, Samir; Hornung, Andreas

    2016-01-01

    Producing energy from biomass and other organic waste residues is essential for sustainable development. Fraunhofer UMSICHT has developed a novel reactor which introduces the Thermo-Catalytic Reforming (TCR®) process. The TCR® is a process which can convert any type of biomass and organic feedstocks into a variety of energy products (char, bio-oil and permanent gases). The aim of this work was to demonstrate this technology using digestate as the feedstock and to quantify the results from the post reforming step. The temperature of a post reformer was varied to achieve optimised fuel products. The hydrogen rich permanent gases produced were maximised at a post reforming temperature of 1023 K. The highly de-oxygenated liquid bio-oil produced contained a calorific value of 35.2 MJ/kg, with significantly improved fuel physical properties, low viscosity and acid number. Overall digestate showed a high potential as feedstock in the Thermo-Catalytic Reforming to produce pyrolysis fuel products of superior quality. PMID:26190827

  19. Reversing flow catalytic converter for a natural gas/diesel dual fuel engine

    Energy Technology Data Exchange (ETDEWEB)

    Liu, E.; Checkel, M.D. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering; Hayes, R.E. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering; Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering; Zheng, M.; Mirosh, E. [Alternative Fuel Systems Inc., Calgary, AB (Canada)

    2001-07-01

    An experimental and modelling study was performed for a reverse flow catalytic converter attached to a natural gas/diesel dual fuel engine. The catalytic converter had a segmented ceramic monolith honeycomb substrate and a catalytic washcoat containing a predominantly palladium catalyst. A one-dimensional single channel model was used to simulate the operation of the converter. The kinetics of the CO and methane oxidation followed first-order behaviour. The activation energy for the oxidation of methane showed a change with temperature, dropping from a value of 129 to 35 kJ/mol at a temperature of 874 K. The reverse flow converter was able to achieve high reactor temperature under conditions of low inlet gas temperature, provided that the initial reactor temperature was sufficiently high. (author)

  20. Kinetics of catalytically activated aggregation—fragmentation process

    International Nuclear Information System (INIS)

    We propose a catalytically activated aggregation—fragmentation model of three species, in which two clusters of species A can coagulate into a larger one under the catalysis of B clusters; otherwise, one cluster of species A will fragment into two smaller clusters under the catalysis of C clusters. By means of mean-field rate equations, we derive the asymptotic solutions of the cluster-mass distributions ak(t) of species A, which is found to depend strongly on the competition between the catalyzed aggregation process and the catalyzed fragmentation process. When the catalyzed aggregation process dominates the system, the cluster-mass distribution ak(t) satisfies the conventional scaling form. When the catalyzed fragmentation process dominates the system, the scaling description of ak(t) breaks down completely and the monodisperse initial condition of species A would not be changed in the long-time limit. In the marginal case when the effects of catalyzed aggregation and catalyzed fragmentation counteract each other, ak(t) takes the modified scaling form and the system can eventually evolve to a steady state. (condensed matter: structural, mechanical, and thermal properties)

  1. Thermodynamic characteristics of a low concentration methane catalytic combustion gas turbine

    International Nuclear Information System (INIS)

    Low concentration methane, emitted from coal mines, landfill, animal waste, etc. into the atmosphere, is not only a greenhouse gas, but also a waste energy source if not utilised. Methane is 23 times more potent than CO2 in terms of trapping heat in the atmosphere over a timeframe of 100 years. This paper studies a novel lean burn catalytic combustion gas turbine, which can be powered with about 1% methane (volume) in air. When this technology is successfully developed, it can be used not only to mitigate the methane for greenhouse gas reduction, but also to utilise such methane as a clean energy source. This paper presents our study results on the thermodynamic characteristics of this new lean burn catalytic combustion gas turbine system by conducting thermal performance analysis of the turbine cycle. The thermodynamic data including thermal efficiencies and exergy loss of main components of the turbine system are presented under different pressure ratios, turbine inlet temperatures and methane concentrations.

  2. Pyrolysis process for producing fuel gas

    Science.gov (United States)

    Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

    2007-01-01

    Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

  3. Catalytic and Gas-Solid Reactions Involving HCN over Limestone

    DEFF Research Database (Denmark)

    Jensen, Anker; Johnsson, Jan Erik; Dam-Johansen, Kim

    1997-01-01

    In coal-fired combustion systems solid calcium species may be present as ash components or limestone added to the combustion chamber. In this study heterogeneous reactions involving HCN over seven different limestones were investigated in a laboratory fixed-bed quartz reactor at 873-1,173 K....... Calcined limestone is an effective catalyst for oxidation of HCN. Under conditions with complete conversion of HCN at O-2 concentrations above about 5,000 ppmv the selectivity for formation of NO and N2O is 50-70% and below 5%, respectively. Nitric oxide can be reduced by HCN to N-2 in the absence of O-2...... decreases with increasing degree of sulfation. Simultaneously the selectivity for formation of NO decreases while that for N2O increases. The catalytic activity of sulfated limestone increases with decreasing SO2 concentration indicating a competition between SO2 and HCN for sites on the surface. The...

  4. Catalytic conversion of natural gas by its combustion products

    Energy Technology Data Exchange (ETDEWEB)

    Chalyuk, G.I.; Krivokon, A.A.; Nosach, V.G.; Veselov, V.V.

    1983-01-01

    The kinetics are studied of the conversion of natural gas (PG) by the products of its combustion in a nickel catalyst (Kt) in order to increase the effectiveness of using natural gas as a fuel. The conversion was conducted in a through installation with a pressure close to atmospheric at a temperature of 700 to 850 degrees, a cubic speed of CH/sub 4/ of 1,000 to 4,000 per hours and a CH/sub 4/ to oxidizer ratio of 1 to 3. A ground KSN-2 catalyst with a size of two thirds of a millimeter which contained 10 percent nickel was used. The natural gas directed for conversion was first purified of sulfurous compounds. The oxidizer is a model mixture (an artificial flue gas) which consists of N/sub 2/, CO/sub 2/ and H/sub 2/O. The dependences of the degree of conversion of CH/sub 4/ on the contact time of the gas in the reaction zone and on the cubic speed are found, as well as the dependence of the concentration of the unreacted CH/sub 4/ in the converted gas on the temperature at different cubic speeds. The mean value of the order of the reaction based on CH/sub 4/ is 1.3; 1.2; 0.9 and 1.0 at a temperature of 700, 750, 800 and 850 degrees, respectively.

  5. COMPARISON OF WEST GERMAN AND U.S. FLUE GAS DESULFURIZATION AND SELECTIVE CATALYTIC REDUCTION COSTS

    Science.gov (United States)

    The report documents a comparison of the actual cost retrofitting flue gas desulfurization (FGD) and selective catalytic reduction (SCR) on Federal Republic of German (FRG) boilers to cost estimating procedures used in the U.S. to estimate the retrofit of these controls on U.S. b...

  6. Radioactive gas processing facility

    International Nuclear Information System (INIS)

    Purpose: To safely and surely process water containing radioactive materials removed by a demister disposed to the upstream of a radioactive material capturing filter device and prevent them from leaking to the outside of the system. Constitution: Upon occurrence of LOCA, water content in processed gases sent from a blower started by an automatic start signal are removed by a demister, flown downwardly and then stored in a communication pipe. The stored drain water is evaporated by heating from a water evaporating heater and, after circulated to the downstream pipeline of the filter, released by way of a draining pipe into the atmosphere. Water soluble radioactive materials are contained in the drain water removed by the demister and flown into the communication pipe. Accordingly, after the accident has been cleared a small amount of drain water remained after the heater evaporation may be contained within the drain container by opening a drain valve, by which transportation or re-processing of the drain water is facilitated. (Horiuchi, T.)

  7. Gasoline from natural gas by sulfur processing

    Energy Technology Data Exchange (ETDEWEB)

    Erekson, E.J.; Miao, F.Q. [Institute of Gas Technology, Des Plaines, IL (United States)

    1995-12-31

    The overall objective of this research project is to develop a catalytic process to convert natural gas to liquid transportation fuels. The process, called the HSM (Hydrogen Sulfide-Methane) Process, consists of two steps that each utilize a catalyst and sulfur-containing intermediates: (1) converting natural gas to CS{sub 2} and (2) converting CS{sub 2} to gasoline range liquids. Catalysts have been found that convert methane to carbon disulfide in yields up to 98%. This exceeds the target of 40% yields for the first step. The best rate for CS{sub 2} formation was 132 g CS{sub 2}/kg-cat-h. The best rate for hydrogen production is 220 L H{sub 2} /kg-cat-h. A preliminary economic study shows that in a refinery application hydrogen made by the HSM technology would cost $0.25-R1.00/1000 SCF. Experimental data will be generated to facilitate evaluation of the overall commercial viability of the process.

  8. Modeling and simulation of hydrodemetallation and hydrodesulfurization processes with transient catalytic efficiency

    Directory of Open Access Journals (Sweden)

    E.M. Matos

    2000-06-01

    Full Text Available A model is presented for the description of the concentration behavior of organometallic and sulfurated compounds in hydrodemetallation and hydrodesulfurization catalytic processes, where catalyst effectiveness decreases with time. Due to the complexity of the mixture, an approach based on pseudocomponents was adopted. The system is modeled as an isothermal tubular reactor with axial dispersion, where the gas phase (hydrogen in excess flows upward concurrently with the liquid phase (heavy oil while the solid phase (catalyst stays inside the reactor in an expanded (confined bed regime. The catalyst particles are very small and are assumed to be uniformly distributed in the reactor. The heavy oil fractions contain organometallics and sulfurated compounds, from which the metals and sulfur are to be removed, the metals as deposits in the catalyst pores and the sulfur as gas products. Simulations were carried out where the concentration profile inside the reactor was calculated for several residence times.

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

    Directory of Open Access Journals (Sweden)

    Sathaporn Chuepeng

    2012-01-01

    Full Text Available 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 gas catalytic converter affected by gas velocity and inlet temperature using numerical modeling. Approach: The simulation was based on a one-dimensional time-dependent model within a single monolith channel of the converter. Upon certain assumptions, the study was considered heterogeneous combustion reaction between gas and solid phases based on lumped kinetic reactions. In this study, constants and variables used for mass and heat transfers were dependent on gas or solid phase temperature and mole fraction. Finite difference scheme incorporated with the generated computer code was established for solving species and energy balances within gas and solid phases. Results: The NO conversion was increased with transient period in initial and reached steady state at different values. The lower inlet gas temperature was resulted in lesser NO conversion at the same inlet NO concentration and gas velocity. The light-off temperatures were up to 520 K and a sudden rise in NO conversion was from 550-605 K and decreasing onwards, generating working temperature window. NO conversion increased throughout the catalyst bed from the inlet and the conversion decreased as the gas velocity increased. Conclusion/Recommendations: Gas space velocity and gas temperature intake to the converter affected the NO conversion over the time and the axial distance from the catalyst bed inlet. The numerical results have summarily demonstrated a good approximation compared to experimental

  10. Wet flue gas desulfurization processes

    OpenAIRE

    Hayrunnisa Çavuşoğlu; Mustafa Şahin Gülaboğlu

    2013-01-01

    The wet flue gas desulfurization process is widely used for the treatment of exhaust gases in power stations. Due to its high level of effectiveness over the already available processes, it has also been the mostly preferred method by industry. Its high SO2 removal efficiency, wide applicability of absorption chemicals and the ease of the chemical process handling which does not require comprehensive konowledge are among the main advantages of this process. In this article, various wet flue g...

  11. Capturing value from gas processing

    International Nuclear Information System (INIS)

    This paper reports that if you are looking for a way to create value, you may not have to look any further than your gas processing assets. Capturing value from gas processing may seem impossible, given the tough times the industry has been experiencing. But gas processing is moving into a new era and some early movers are already capitalizing on the opportunities being created. They are making real cuts in operating costs. They are not afraid of the R word (rationalization). And they are creating or strengthening attributes that give them a unique competitive advantage. What are these efforts worth? The authors estimate that they can increase the value of gas processing assets by up to 150 percent. For a typical 100 MMcfd processing facility, that could mean $100 million. If you want to make more from your gas processing assets, it is important to understand the forces that have been pushing the industry into a new era. You also need to take a closer look at what early movers are doing and the value creation opportunities for companies and the industry as a whole. All of that will provide a context for thinking about how your company can capture those opportunities

  12. Thermodynamic analysis of hydrogen rich synthetic gas generation from fluidized bed gasification of rice husk

    International Nuclear Information System (INIS)

    In the present work, the generation of hydrogen rich synthetic gas from fluidized bed steam gasification of rice husk has been studied. An equilibrium model based on equilibrium constant and material balance has been developed to predict the gas compositions. The equilibrium gas compositions are compared with the experimental data of the present group as well as of available literature. The energy and exergy analysis of the process have been carried out by varying steam to biomass ratio (ψ) within the range between 0.1-1.5 and gasification temperature from 600 oC to 900 oC. It is observed that both the energy and exergy efficiencies are maximum at the CBP (carbon boundary point) though the hydrogen production increases beyond the CBP. The HHV (higher heating value) and the external energy input both continuously increase with ψ. However, the hydrogen production initially increases with increase in temperature up to 800 oC and then becomes nearly asymptotic. The HHV decreases rapidly with increase in temperature and energy input increases. Therefore, gasification in lower temperature region is observed to be economical in terms of a trade off between external energy input and HHV of the product gas. -- Highlights: → Energy and exergy analysis of hydrogen rich synthetic gas generation from fluidized bed steam gasification of rice husk. → Effect of steam-to-biomass ration and gasification temperature is studied. → Maximum efficiencies occur at the (CBP) carbon boundary point though the hydrogen production increases beyond CBP. → Gasification in lower temperature region is observed to be optimum.

  13. 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.

  14. Oxidation of hydrogen halides to elemental halogens with catalytic molten salt mixtures

    Science.gov (United States)

    Rohrmann, Charles A.

    1978-01-01

    A process for oxidizing hydrogen halides by means of a catalytically active molten salt is disclosed. The subject hydrogen halide is contacted with a molten salt containing an oxygen compound of vanadium and alkali metal sulfates and pyrosulfates to produce an effluent gas stream rich in the elemental halogen. The reduced vanadium which remains after this contacting is regenerated to the active higher valence state by contacting the spent molten salt with a stream of oxygen-bearing gas.

  15. Low-temperature plasma-catalytic oxidation of formaldehyde in atmospheric pressure gas streams

    International Nuclear Information System (INIS)

    Formaldehyde (HCHO) is a typical air pollutant capable of causing serious health disorders in human beings. This work reports plasma-catalytic oxidation of formaldehyde in gas streams via dielectric barrier discharges over Ag/CeO2 pellets at atmospheric pressure and 70 0C. With a feed gas mixture of 276 ppm HCHO, 21.0% O2, 1.0% H2O in N2, ∼99% of formaldehyde can be effectively destructed with an 86% oxidative conversion into CO2 at GHSV of 16500 h-1 and input discharge energy density of 108 J l-1. At the same experimental conditions, the conversion percentages of HCHO to CO2 from pure plasma-induced oxidation (discharges over fused silica pellets) and from pure catalytic oxidation over Ag/CeO2 (without discharges) are 6% and 33% only. The above results and the CO plasma-catalytic oxidation experiments imply that the plasma-generated short-lived gas phase radicals, such as O and HO2, play important roles in the catalytic redox circles of Ag/CeO2 to oxidize HCHO and CO to CO2

  16. Microwave and Conventional Pyrolysis of Coffee Hulls at Different Temperatures for a Hydrogen Rich Gas

    OpenAIRE

    Menendez, Angel; Fernandez, Yolanda; Dominguez, Antonio; Pis, Juan; Valente Nabais, Joao; Carrott, Peter; Carrott, Manuela

    2006-01-01

    Microwave and Conventional Pyrolysis of Coffee Hulls at Different Temperatures for a Hydrogen Rich Gas. The paper reports the comparison of using a microwave and a conventional furnace to do the pysolysis of the coffee hulls.

  17. Numerical and experimental study on shear coaxial injectors with hot hydrogen-rich gas/oxygen-rich gas and GH2/GO2

    Institute of Scientific and Technical Information of China (English)

    Jin Ping; Li Mao; Cai Guo-Biao

    2013-01-01

    The influences of the shear coaxial injector parameters on the combustion performance and the heat load of a combustor are studied numerically and experimentally.The injector parameters,including the ratio of the oxidizer pressure drop to the combustor pressure (Dp),the velocity ratio of fuel to oxidizer (Rv),the thickness (Wo),and the recess (Ho) of the oxidizer injector post tip,the temperature of the hydrogen-rich gas (TH) and the oxygen-rich gas (To),are integrated by the orthogonal experimental design method to investigate the performance of the shear coaxial injector.The gaseous hydrogen/oxygen at ambient temperature (GH2/GO2),and the hot hydrogen-rich gas/oxygen-rich gas are used here.The length of the combustion (Lc),the average temperatures of the combustor wall (Tw),and the faceplate (TF) are selected as the indicators.The tendencies of the influences of injector parameters on the combustion performance and the heat load of the combustor for the GH2/GO2 case are similar to those in the hot propellants case.However,the combustion performancein the hot propellant case is better than that in the GH2/GO2 case,and the heat load of the combustor is also larger than that in the latter case.

  18. Database implementation to fluidized cracking catalytic-FCC process

    International Nuclear Information System (INIS)

    A process of Fluidized Cracking Catalytic (FCC) was developed by our research group. A cold model FCC unit, in laboratory scale, was used for obtaining of the data relative to the following parameters: air flow, system pressure, riser inlet pressure, rise outlet pressure, pressure drop in the riser, motor speed of catalyst injection and density. The measured of the density is made by gamma ray transmission. For the fact of the process of FCC not to have a database until then, the present work supplied this deficiency with the implementation of a database in connection with the Matlab software. The data from the FCC unit (laboratory model) are obtained as spreadsheet of the MS-Excel software. These spreadsheets were treated before importing them as database tables. The application of the process of normalization of database and the analysis done with the MS-Access in these spreadsheets treated revealed the need of an only relation (table) for to represent the database. The Database Manager System (DBMS) chosen has been the MS-Access by to satisfy our flow of data. The next step was the creation of the database, being built the table of data, the action query, selection query and the macro for to import data from the unit FCC in study. Also an interface between the application 'Database Toolbox' (Matlab2008a) and the database was created. This was obtained through the drivers ODBC (Open Data Base Connectivity). This interface allows the manipulation of the database by the users operating in the Matlab. (author)

  19. Modeling of catalytic ozonation process in a three-phase reactor.

    Science.gov (United States)

    Erol, Funda; Ozbelge, Tülay A; Ozbelge, H Onder

    2009-02-15

    In this research, the main objective was to determine the flow characteristics of a three-phase reactor in order to use this knowledge in the modeling of catalytic ozonation of aqueous dye solutions. Therefore, the stimulus-response method was used in the tracer experiments; thus, the degree of liquid mixing in the reactor was estimated by means of residence time distribution, Peclet number and axial dispersion coefficient in the presence and the absence of the catalyst. Experimental data were obtained by performing the catalytic ozonation of aqueous Acid Red-151(AR-151) and Remazol Brilliant Blue-R (RBBR) dye solutions, in the presence of perfluorinated-octyl-alumina (PFOA) catalyst particles at different operating conditions. The chemical oxygen demand (COD), the dye and ozone concentrations in the liquid phase were measured at the steady state along the height of the column reactor and at the exit. According to the results, it was observed that the gas-liquid reactor without the catalyst particles showed a hydrodynamic behavior equivalent to two or three completely stirred tank reactors (CSTRs) in-series for the conventional ozonation process. The presence of catalyst particles caused the flow behavior of the three phase reactor to approach to one CSTR or two CSTRs in-series depending on the gas and liquid flow rates so that the modeling of the catalytic ozonation process was done satisfactorily on that basis. The modeling results showed satisfactory agreement with the experimental ones in the prediction of outlet dye and dissolved ozone concentrations from the reactor, especially at relatively high gas velocities (QG=150 and 200 L h(-1)) for AR-151, where the dissolved ozone concentration was not limited. However, the discrepancy was about 15% between the theory and experiment at the lower gas flow rates due to the limited ozone concentrations with respect to the dye concentrations at the high inlet dye concentration of AR-151 (CD,i=100 mg L(-1)). For RBBR, the

  20. Processing of mixed waste via quantum-catalytic extraction processing (Q-CEP trademark), a case study

    International Nuclear Information System (INIS)

    Catalytic Extraction Processing (CEP) as developed by Molten Metal Technology (MMT), Inc. employs the use of a refractory-lined, steel-shell reactor vessel and an inductively-heated metal bath. When molten, the metal bath can process gaseous, liquid, and solid wastes and recycle their constituents into commercially valuable products. Quantum-Catalytic Extraction Processing, or Q-CEP, is the application of CEP technology to radioactive and mixed wastes. The Q-CEP technology can take wastes in various physical forms (gas, liquid, slurry, sludge, or grindable solid) and inject them into the molten metal bath of iron, nickel, or copper. The bath acts as both a catalyst and solvent and breaks the compounds of the waste feed into their original constituent elements. The flexibility and robustness of the Q-CEP process are attributed to the open-quote singular close-quote dissolved elemental intermediate through which reactions proceed. open-quotes Singular close-quote refers to the fact that the catalytic and salvation effects of the liquid metal ensure that the constituents of the feed are only found in the liquid metal as dissolved elements (e.g. dissolved carbon). As a result, Q-CEP feed conversion is independent of the complexity of the molecular structure of the feed molecule. Destruction and Removal Efficiencies (DREs) exceeding 99.9999% (six nines) are typical in CEP regardless of the complexity of feed materials. Q-CEP is not a combustion technology. Unlike incineration where wastes are volume reduced and residuals buried, Q-CEP allows for the formation of commercially valuable products. Chemical reactions are performed in a highly reducing environment which results in extremely low concentrations of free oxygen, preventing the formation of furans, dioxins, or other products of incomplete combustion

  1. Novel catalytic converter for natural gas powered diesel engines to meet stringent exhaust emission regulations

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, M.; Mirosh, E.A. [Alternative Fuel Systems Inc. (Canada); Matros, Yu.S.; Bunimovich, G.A.; Strots, V.O. [Matros Technologies Inc. (United States); Sallamie, N.; Checkel, M.D. [Alberta Univ. (Canada); Windawi, H. [Johnson Matthey (United States)

    1998-12-31

    The implementation of stringent exhaust emission regulations has led to the development of natural gas powered dual fuel systems with electronic multiport injection. The high compression ratio of the baseline diesel engine was maintained to keep the high thermal efficiency of diesel cycles. The dual fuel system is mainly powered by natural gas and ignited by a diesel pilot. Extensive experimental results indicate that the diesel dual fuel system provides simultaneous reductions in NO{sub x} and particulate emissions. The system also has low exhaust THC and CO under heavy-duty operations. With the combined use of exhaust gas recirculation and catalytic converter, low emission operation has been extended to a larger range, from medium to full loads for all testing speeds. However, conventional converters exhibit poor conversion efficiency at low engine loads due to the low exhaust temperature levels. This leads to increased exhaust emissions during low load operations, especially for the non-reactive hydrocarbons, specifically, methane. To solve this problem, a novel automotive exhaust gas aftertreatment system - the reversing flow catalytic converter - has been developed. The prototype Reversing Flow Converter (RFC) consists of a diversion flow valve and a catalytic monolith converter. The diversion valve periodically re-directs the engine exhaust flow through the catalyst in alternative directions. The duration of flow in each direction is determined by engine operating conditions to obtain an ideal temperature profile along the axis of the monolith. The catalytic converter was designed to have high methane conversion efficiency. Associated techniques, such as retarding fuel injection, exhaust gas recirculation, and the variation of diesel pilot to natural gas ratio, can be used to raise exhaust temperature and bring the catalytic converter to light-off temperatures quicker. Engine dynamometer tests showed that CO conversion rate was above 95% and CH{sub 4

  2. Investigation of combustion and thermodynamic performance of a lean burn catalytic combustion gas turbine system

    International Nuclear Information System (INIS)

    The goals of this research were to investigate the combustion and thermodynamic performance of a lean burn catalytic combustion gas turbine. The characteristics of lean burn catalytic combustion were investigated by utilising 1D heterogeneous plug flow model which was validated by experiments. The effects of operating parameters on catalytic combustion were numerically analysed. The system models were built in ASPEN Plus and three independent design variables, i.e. compressor pressure ratio (PR), regenerator effectiveness (RE) and turbine inlet temperature (TIT) were selected to analyse the thermodynamic performance of the thermal cycle. The main results show that: simulations from 1D heterogeneous plug flow model can capture the trend of catalytic combustion and describe the behavior of the catalytic monolith in detail. Inlet temperature is the most significant parameter that impacts operation of the catalytic combustor. When TIT and RE are constant, the increase of PR results in lowering the inlet temperature of the catalytic combustor, which results in decreasing methane conversion. The peak thermal efficiency and the optimal PR at a constant TIT increase with the increase of TIT; and at the constant PR, the thermal efficiency increases with the increase of TIT. However, with lower TIT conditions, the optimal PR and the peak efficiency at a constant TIT of the LBCCGT cycle are relative low to that of the conventional cycle. When TIT and PR are constant, the decrease of RE may result in lower methane conversion. The influences of RE on the methane conversion and the thermal efficiency are more significant at higher PRs. The higher thermal efficiency for the lower RE is achieved at lower PR.

  3. Long-time experience in catalytic flue gas cleaning and catalytic NO{sub x} reduction in biofueled boilers

    Energy Technology Data Exchange (ETDEWEB)

    Ahonen, M. [Tampella Power Inc., Tampere (Finland)

    1996-12-31

    NO emissions are reduced by primary or secondary methods. Primary methods are based on NO reduction in the combustion zone and secondary methods on flue gas cleaning. The most effective NO reduction method is selective catalytic reduction (SCR). It is based on NO reduction by ammonia on the surface of a catalyst. Reaction products are water and nitrogen. A titanium-dioxide-based catalyst is very durable and selective in coal-fired power plants. It is not poisoned by sulphur dioxide and side reactions with ammonia and sulphur dioxide hardly occur. The long time experience and suitability of a titanium-dioxide-based catalyst for NO reduction in biofuel-fired power plants was studied. The biofuels were: peat, wood and bark. It was noticed that deactivation varied very much due to the type of fuel and content of alkalinities in fuel ash. The deactivation in peat firing was moderate, close to the deactivation noticed in coal firing. Wood firing generally had a greater deactivation effect than peat firing. Fuel and fly ash were analyzed to get more information on the flue gas properties. The accumulation of alkali and alkaline earth metals and sulphates was examined together with changes in the physical composition of the catalysts. In the cases where the deactivation was the greatest, the amount of alkali and alkaline earth metals in fuels and fly ashes and their accumulation were very significant. (author) (3 refs.)

  4. A 25 kWe low concentration methane catalytic combustion gas turbine prototype unit

    International Nuclear Information System (INIS)

    Low concentration methane, emitted from various industries e.g. coal mines and landfills into atmosphere, is not only an important greenhouse gas, but also a wasted energy resource if not utilized. In the past decade, we have been developing a novel VAMCAT (ventilation air methane catalytic combustion gas turbine) technology. This turbine technology can be used to mitigate methane emissions for greenhouse gas reduction, and also to utilize the low concentration methane as an energy source. This paper presents our latest research results on the development and demonstration of a 25 kWe lean burn catalytic combustion gas turbine prototype unit. Recent experimental results show that the unit can be operated with 0.8 vol% of methane in air, producing about 19–21 kWe of electricity output. - Highlights: • A novel low concentration methane catalytic turbine prototype unit was developed. • The 25 kWe unit can be operated with ∼0.8 vol.% CH4 in air with 19–21 kWe output. • A new start-up method was developed for the prototype unit

  5. Fuel Flexible, Low Emission Catalytic Combustor for Opportunity Fuel Applications

    Energy Technology Data Exchange (ETDEWEB)

    Eteman, Shahrokh

    2013-06-30

    Limited fuel resources, increasing energy demand and stringent emission regulations are drivers to evaluate process off-gases or process waste streams as fuels for power generation. Often these process waste streams have low energy content and/or highly reactive components. Operability of low energy content fuels in gas turbines leads to issues such as unstable and incomplete combustion. On the other hand, fuels containing higher-order hydrocarbons lead to flashback and auto-ignition issues. Due to above reasons, these fuels cannot be used directly without modifications or efficiency penalties in gas turbine engines. To enable the use of these wide variety of fuels in gas turbine engines a rich catalytic lean burn (RCL®) combustion system was developed and tested in a subscale high pressure (10 atm.) rig. The RCL® injector provided stability and extended turndown to low Btu fuels due to catalytic pre-reaction. Previous work has shown promise with fuels such as blast furnace gas (BFG) with LHV of 85 Btu/ft3 successfully combusted. This program extends on this work by further modifying the combustor to achieve greater catalytic stability enhancement. Fuels containing low energy content such as weak natural gas with a Lower Heating Value (LHV) of 6.5 MJ/m3 (180 Btu/ft3 to natural gas fuels containing higher hydrocarbon (e.g ethane) with LHV of 37.6 MJ/m3 (1010 Btu/ft3) were demonstrated with improved combustion stability; an extended turndown (defined as the difference between catalytic and non-catalytic lean blow out) of greater than 250oF was achieved with CO and NOx emissions lower than 5 ppm corrected to 15% O2. In addition, for highly reactive fuels the catalytic region preferentially pre-reacted the higher order hydrocarbons with no events of flashback or auto-ignition allowing a stable and safe operation with low NOx and CO emissions.

  6. Oxygen transport membrane system and method for transferring heat to catalytic/process reactors

    Science.gov (United States)

    Kelly, Sean M; Kromer, Brian R; Litwin, Michael M; Rosen, Lee J; Christie, Gervase Maxwell; Wilson, Jamie R; Kosowski, Lawrence W; Robinson, Charles

    2014-01-07

    A method and apparatus for producing heat used in a synthesis gas production is provided. The disclosed method and apparatus include a plurality of tubular oxygen transport membrane elements adapted to separate oxygen from an oxygen containing stream contacting the retentate side of the membrane elements. The permeated oxygen is combusted with a hydrogen containing synthesis gas stream contacting the permeate side of the tubular oxygen transport membrane elements thereby generating a reaction product stream and radiant heat. The present method and apparatus also includes at least one catalytic reactor containing a catalyst to promote the stream reforming reaction wherein the catalytic reactor is surrounded by the plurality of tubular oxygen transport membrane elements. The view factor between the catalytic reactor and the plurality of tubular oxygen transport membrane elements radiating heat to the catalytic reactor is greater than or equal to 0.5.

  7. Gas purification using membrane gas absorption processes

    OpenAIRE

    Dindore, Vishwas Yashwant

    2003-01-01

    Owing to the increasing energy demand and the abundance of low quality natural gas reservoirs containing high percentages of CO2, considerable attention is given to the bulk removal of CO2 and upgrading of low quality natural gas. The main goal in doing so is to increase the heating value of natural gas and to reduce the transportation cost.

  8. A flameless catalytic combustion-based thermoelectric generator for powering electronic instruments on gas pipelines

    International Nuclear Information System (INIS)

    Highlights: ► MPPT is used to improve the feature that TEG output is sensitive to load variation. ► The improved feature makes TEG suitable to power electronic device on gas pipeline. ► Test shows heat transfer uniformity plays an important role in improving TEG output. ► It can get an optimized TEG by uniformly filling a thermal insulation material. - Abstract: This paper presents a flameless catalytic combustion-based thermoelectric power generator that uses commercial thermoelectric modules. The structure of the thermoelectric generator (TEG) is introduced and the power performance is measured based on a designed circuit system. The open circuit voltage of the TEG is about 7.3 V. The maximum power output can reach up to 6.5 W when the load resistance matches the TEG internal resistance. However, the system output is sensitive to load variation. To improve this characteristic, maximum power point tracking technique is used and results in an open circuit voltage of 13.8 V. The improved characteristic makes the TEG system a good charger to keep the lead acid battery fully charged so as to meet the needs of electronic instruments on gas pipelines. In addition, the combustion features have been investigated based on the temperature measurement. Test results show that the uniformity of combustion heat transfer process and the combustion chamber structure play important roles in improving system power output. It can get an optimized TEG system (maximum power output: 8.3 W) by uniformly filling a thermal insulation material (asbestos) to avoid a non-uniform combustion heat transfer process

  9. Catalytic technology in the energy/environment field. Utilization of catalyst in coal pyrolysis and gasification processes; Energy kankyo bun`ya ni okeru shokubai gijutsu. Sekitan no netsubunkai oyobi gas ka ni okeru shokubai no riyo

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Y. [Tohoku University, Institute for Chemical Reaction Science (Japan)

    1998-05-20

    This review article focuses on the utilization of several catalysts during coal pyrolysis and gasification. In situ or off line catalytic upgrading of volatile matters during pyrolysis of low rank coals is carried out in pressurized H2 with different reactors to produce BTX (benzene, toluene and xylene). When NiSO4 and Ni(OH)2 are used in the hydropyrolysis of Australian brown coal using an entrained bed reactor with two separated reaction zones, BTX yield reaches 18-23%. MS-13X zeolite and USY zeolite mixed with Al2O3 are effective for producing BTX with powder-particle fluidized bed and two-stage reactors, respectively. Catalytic gasification is described from a standpoint of direct production of SNG(CH4) from coal and steam. When K2CO3 and Ni are compared for this purpose, Ni catalyst is more suitable at low temperatures of 500-600degC, where CH4 formation is thermodynamically favorable. Fe and Ca catalysts can successfully be prepared from inexpensive raw materials and are rather active for steam gasification at {>=}700degC. The use of upgrading and gasification catalysts is discussed in terms of preparation, performance, life and recovery. 27 refs., 6 figs., 2 tabs.

  10. Hydrogen rich gas production by thermocatalytic decomposition of kenaf biomass

    Energy Technology Data Exchange (ETDEWEB)

    Irmak, Sibel; Oeztuerk, ilker [Department of Chemistry, Cukurova University, Arts and Sciences Faculty, Adana 01330 (Turkey)

    2010-06-15

    Kenaf (Hibiscus cannabinus L.), a well known energy crop and an annual herbaceous plant grows very fast with low lodging susceptibility was used as representative lignocellulosic biomass in the present work. Thermocatalytic conversions were performed by aqueous phase reforming (APR) of kenaf hydrolysates and direct gasification of solid biomass of kenaf using 5% Pt on activated carbon as catalyst. Hydrolysates used in APR experiments were prepared by solubilization of kenaf biomass in subcritical water under CO{sub 2} gas pressure. APR of kenaf hydrolysate with low molecular weight polysaccharides in the presence of the reforming catalyst produced more gas compared to the hydrolysate that had high molecular weight polysaccharides. APR experiments of kenaf biomass hydrolysates and glucose, which was used as a simplest biomass model compound, in the presence of catalyst produced various amounts of gas mixtures that consisted of H{sub 2}, CO, CO{sub 2}, CH{sub 4} and C{sub 2}H{sub 6}. The ratios of H{sub 2} to other gases produced were 0.98, 1.50 and 1.35 for 150 C and 250 C subcritical water-treated kenaf hydrolysates and glucose, respectively. These ratios indicated that more the degraded organic content of kenaf hydrolysate the better selectivity for hydrogen production. Although APR of 250 C-kenaf hydrolysate resulted in similar gas content and composition as glucose, the gas volume produced was three times higher in glucose feed. The use of solid kenaf biomass as starting feedstock in APR experiments resulted in less gas production since the activity of catalyst was lowered by solid biomass particles. (author)

  11. Numerical simulation of catalytic methanation process of producing natural gas using coal%煤制天然气过程催化甲烷化的数值模拟

    Institute of Scientific and Technical Information of China (English)

    王翠苹; 李刚; 李厚洋; 姜旭

    2015-01-01

    两步法煤制天然气的第一步反应主要生产粗煤气CO和 H2,调整CO与 H2的比值后进行甲烷化反应。在计算软件HSC中分别控制反应温度、压力和CO与H2比例,计算了甲烷化产物变化规律,得到第二步甲烷化反应最适条件是1.8 M Pa、700℃;通过在计算软件FL U EN T 中进行一步对催化甲烷化反应的模拟,0.1 M Pa、720℃时的催化甲烷化即可达到无催化高压条件的甲烷摩尔产率,甲烷化产率最高时对应的n(H2)∶ n(C O )比值为1.8。%The main products from the first step reaction of the two‐step coal gasification are CO and H2 ,and the ratio of CO to H2 can be adjusted for the next methanation reaction step .A computing software HSC was used to compute the methanation product changing trend by controlling the reaction temperature , pressure and CO/H2 ratio , and the optimum condition for the second step reaction was derived as 1 .8 MPa and 700 ℃ .The catalytic methanation reaction was simulated using commercial software Fluent ,and the coal gasification and methanation reaction occurred successively in a one‐step reactor .The methanation productivity of catalytic methanation under the condition of 720 ℃ and 0 .1 MPa is comparable to the high pressure production without catalytic reaction .The CO/H2 ratio of is up to 1 .8 w hen the highest methanation yield is achieved .

  12. The generation of electricity by gas turbines using the catalytic combustion of low-Btu gases

    OpenAIRE

    Frederiksen, O.P.; Qvale, Einar Bjørn

    1989-01-01

    Various systems for the generation of electricity by gas turbines using catalytic combustion of low-Btu gases have been investigated. Parametric studies of three configurations that are deemed to be practically feasible have been completed. It is shown that thermodynamic efficiency of these systems may be quite high. The system design has been made to comply with generally accepted limitations on the operation of the compressors, turbines and heat exchangers. The heat catalyst has been invest...

  13. Noble gas isotopes and halogens in volatile-rich inclusions in diamonds

    Science.gov (United States)

    Burgess, Raymond; Turner, Grenville

    1994-01-01

    Application of the (40)Ar-(39)Ar method and noble gas studies to diamonds has increased our understanding of their age relationships to the host kimberlite or lamproite, and of the source and composition of volatile-rich fluids in the upper mantle. The properties of diamond (inert, high mechanical strength and low gas diffusivities) means they are especially useful samples for studying gases trapped deep within the earth (less than 150 km) as they are unlikely to have undergone loss or exchange of entrapped material since formation. Volatile-rich fluids (H2O-CO2) are important agents for metasomatic processes in the upper mantle, and the noble gases and halogens preferentially partition into this phase leading to a strong geochemical coherence between these groups of elements. The abundances of the halogens in the major reservoirs of the Earth shows a marked progression from chlorine, concentrated in the oceans, through to iodine which, through its affinity to organic material, is concentrated mainly in sediments. Abundances in the upper mantle are low. This is particularly true for iodine which is of special interest in view of its potential significance as an indicator of sediment recycling and by way of its link to (129)Xe amomalies in the mantle through the low extinct isotope (129)I. Extensions of the (40)Ar-(39)Ar technique enable measurements of halogens and other elements (K, Ca, Ba, U) by production of noble gas isotopes from these species during neutron irradiation. Samples analyzed in this way include 15 coated stones from an unknown source in Zaire, 3 boarts from the Jwaneng and 1 boart from the Orapa kimberlites, both in Botswana.

  14. Catalytic upgrading of gas from biofuels and implementation of electricity production. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Espenaes, Bengt-Goeran; Frostaeng, Sten [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-04-01

    The project aimed at research and development concerning processes for production of fuel gas and systems for production of electricity in the small to intermediate size range (100 kW{sub e} to 5 MW{sub e}. The project included building and testing of a complete 'biomass-to-electricity' chain at scale of 100 kW{sub th}. Research work was focused on improvements in reduction of contents of tar and ammonia, and on the influences from sulphur on nickel catalysts, and from chlorine on dolomite catalysts. The project was divided into four main tasks, comprising 19 work packages which included basic and applied research and process development. The work was to some extent a further development of results obtained in a previous EC project (AIR2-CT93-1436). A pilot plant at scale 100 kW{sub th} was designed and erected by BTG. This system consists of a fluidized bed gasifier, a reversal flow tar converter (RFTC), a gas cooler, dust filter and a gas engine. A main effort was put into the optimisation of the RFTC. Tar contents obtained varied between 50 and 150 mg/Nm{sup 3} . Finally, a short test programme was executed, where the technical feasibility of the RFTC was demonstrated successfully at real conditions in the complete biomass-to-electricity system. Specific investment costs were estimated for scales of 0.4, 1 and 2 MW{sub el}. For the largest scale the specific investment costs were estimated to about 165 ECU/kW{sub el}. The fundamental work consisted of basic investigations of catalysts, catalysed reactions, catalyst poisoning by sulphur and tar characterisation. Issues addressed were such as factors that influence activity of different catalysts for elimination of tars, search for new catalysts and optimal use of known and new catalysts. Detailed kinetics of catalysed reactions that convert tar into desired permanent fuel gas components was determined for the most stable tar components, which play major roles in the overall conversion of tar. The

  15. Snow Lines in Gas Rich Protoplanetary Disks and the Delivery of Volatiles to Planetary Surfaces

    Science.gov (United States)

    Blake, Geoffrey A.

    2016-06-01

    Compared to the Sun and to the gas+dust composition of the interstellar medium from which the solar system formed, the Carbon and Nitrogen content of the bulk silicate Earth (mantle+hydrosphere+atmosphere) is reduced by several orders of magnitude, relative to Silicon. Evidence from primitive bodies as a function of distance from the Sun suggests that at least part of this depletion must occur early in the process of planetesimal assembly. With combined infrared and (sub)mm observations such as those enabled by ground-based 8-10m class telescopes (and in future the James Webb Space Telescope) and the Atacama Large Millimeter Array (ALMA), we can now examine the principal volatile reservoirs of gas rich disks as a function position within the disk and evolutionary state. Key to these studies is the concept of condensation fronts, or 'snow lines,' in disks - locations at which key volatiles such as water, carbon monoxide, or nitrogen first condense from the gas. This talk will review the observational characterization of snow lines in protoplanetary disks, especially recent ALMA observations, and highlight the laboratory astrophysics studies and theoretical investigations that are needed to tie the observational results to the delivery of volatiles to planetary surfaces in the habitable zones around Sun-like stars.

  16. Catalytic Deoxygenation of Fatty Acids: Elucidation of the Inhibition Process

    NARCIS (Netherlands)

    Hollak, S.A.W.; Jong, de K.P.; Es, van D.S.

    2014-01-01

    Catalytic deoxygenation of unsaturated fatty acids in the absence of H2 is known to suffer from significant catalyst inhibition. Thus far, no conclusive results have been reported on the cause of deactivation. Here we show that CC double bonds present in the feed or the products dramatically reduce

  17. Studies and development of high-temperature catalytic materials for application in gas turbine combustion chamber

    Energy Technology Data Exchange (ETDEWEB)

    Papadias, Dennis; Thevenin, Philippe [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2000-04-01

    -based garnets and aluminium titanate. The NZP materials (NaZr{sub 2}(PO{sub 4}){sub 3}) have an ultra-low thermal expansion which gives them the desired properties to stand thermal shocks. However their catalytic activity needs to be improved as they have a T{sub 50} above 520 deg C. The iron containing garnets (YIG) with the following formula Y{sub 3}Fe{sub 5}O{sub 12}, as well as the MgAl{sub 2}O{sub 4} spinel, show promising results with an activity close to the hexaaluminates. Different fuels could be considered for application in gas turbine combustion chambers. Ethanol appears to be a promising alternative fuel for mobile gas turbines, methane and gasified biomass for stationary utilisation. The experimental work in this project has been done using ethanol as fuel. The coming work will be oriented towards gasified biomass as well. Specific attention will be given to fuel-NO{sub x} formation from the ammonia present in the feed. The work was carried out in co-operation with Volvo Aero Corporation, which was involved in the European project AGATA where the objective was to develop a ceramic gas turbine for hybrid car applications. Furthermore, another project within catalytic combustion for gas turbine is conducted in co-operation with the Division of Heat and Power Technology at KTH (Nutek project P7057, Catalytic Combustion of Gasified Biomass). In this projects a fully catalytic system has been chosen. However a solution to overcome the problem given by the high temperature present in the last section of the combustor is a hybrid system described in the literature. A first catalyst segment with low temperature catalytic activity ignites part of the fuel at 300-400 deg C. The rest of the fuel is then burned homogeneously between 1000 - 1400 deg C. This design avoid the use of catalytic material at temperature above 1000 deg C. Different projects are running both in the US (Catalytica Combustion Systems Inc., Precision Combustion) and Japan (Osaka Gas Company) to develop a

  18. Catalytic upgrading of gas from biofuels and implementation of electricity production. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Espenaes, Bengt-Goeran; Frostaeng, Sten [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-04-01

    The project aimed at research and development concerning processes for production of fuel gas and systems for production of electricity in the small to intermediate size range (100 kW{sub e} to 5 MW{sub e}. The project included building and testing of a complete 'biomass-to-electricity' chain at scale of 100 kW{sub th}. Research work was focused on improvements in reduction of contents of tar and ammonia, and on the influences from sulphur on nickel catalysts, and from chlorine on dolomite catalysts. The project was divided into four main tasks, comprising 19 work packages which included basic and applied research and process development. The work was to some extent a further development of results obtained in a previous EC project (AIR2-CT93-1436). A pilot plant at scale 100 kW{sub th} was designed and erected by BTG. This system consists of a fluidized bed gasifier, a reversal flow tar converter (RFTC), a gas cooler, dust filter and a gas engine. A main effort was put into the optimisation of the RFTC. Tar contents obtained varied between 50 and 150 mg/Nm{sup 3} . Finally, a short test programme was executed, where the technical feasibility of the RFTC was demonstrated successfully at real conditions in the complete biomass-to-electricity system. Specific investment costs were estimated for scales of 0.4, 1 and 2 MW{sub el}. For the largest scale the specific investment costs were estimated to about 165 ECU/kW{sub el}. The fundamental work consisted of basic investigations of catalysts, catalysed reactions, catalyst poisoning by sulphur and tar characterisation. Issues addressed were such as factors that influence activity of different catalysts for elimination of tars, search for new catalysts and optimal use of known and new catalysts. Detailed kinetics of catalysed reactions that convert tar into desired permanent fuel gas components was determined for the most stable tar components, which play major roles in the overall conversion of tar. The

  19. Quantitative study of catalytic activity and catalytic deactivation of Fe–Co/Al2O3 catalysts for multi-walled carbon nanotube synthesis by the CCVD process

    OpenAIRE

    Pirard, Sophie; Heyen, Georges; Pirard, Jean-Paul

    2010-01-01

    The catalytic deactivation during multi-walled carbon nanotube (MWNT) synthesis by the CCVD process and the influence of hydrogen on it were quantified. Initial specific reaction rate, relative specific productivity and catalytic deactivation were studied. Carbon source was ethylene, and a bimetallic iron–cobalt catalyst supported on alumina was used. The catalytic deactivation was modeled by a decreasing hyperbolic law, reflecting the progressive accumulation of amorphous carbon on active si...

  20. Selective catalytic reduction (SCR) NOx control for small natural gas-fired prime movers

    International Nuclear Information System (INIS)

    The application of selective catalytic reduction (SCR) to small natural gas-fired prime movers at cogeneration facilities and compressor stations could possibly increase due to regulatory forces to limit NOx from such sources. The natural gas industry is presently without a current database with which to evaluate the cost and operating characteristics of SCR under the conditions anticipated for small prime movers. This paper presents the results from a two-phase study undertaken to document SCR applications with emphasis on SCR system performance and costs. The database of small natural gas-fired prime mover SCR experience, focusing on prime mover characterization, SCR system performance, and SCR system costs will be described. Result from analysis of performance and cost data will be discussed, including analytical tools developed to project SCR system performance and costs

  1. Heterogeneous catalytic process for alcohol fuels from syngas

    Energy Technology Data Exchange (ETDEWEB)

    Minahan, D.M.; Nagaki, D.A.

    1995-12-31

    This project is focused on the discovery and evaluation of novel heterogeneous catalyst for the production of oxygenated fuel enhancers from synthesis gas. Catalysts have been studied and optimized for the production of methanol and isobutanol mixtures which may be used for the downstream synthesis of MTBE or related oxygenates. Higher alcohols synthesis (HAS) from syngas was studied; the alcohols that are produced in this process may be used for the downstream synthesis of MTBE or related oxygenates. This work has resulted in the discovery of a catalyst system that is highly selective for isobutanol compared with the prior art. The catalysts operate at high temperature (400{degrees}C), and consist of a spinel oxide support (general formula AB{sub 2}O{sub 4}, where A=M{sup 2+} and B = M{sup 3+}), promoted with various other elements. These catalysts operate by what is believed to be an aldol condensation mechanism, giving a product mix of mainly methanol and isobutanol. In this study, the effect of product feed/recycle (methanol, ethanol. n-propanol, isopropanol, carbon dioxide and water) on the performance of 10-DAN-55 (spinel oxide based catalyst) at 400{degrees}C, 1000 psi, GHSV = 12,000 and syngas (H{sub 2}/CO) ratio = 1:2 (alcohol addition) and 1:1 (carbon dioxide and water addition) was studied. The effect of operation at high temperatures and pressures on the performance of an improved catalyst formulation was also examined.

  2. China organic-rich shale geologic features and special shale gas production issues

    Directory of Open Access Journals (Sweden)

    Yiwen Ju

    2014-06-01

    Full Text Available The depositional environment of organic-rich shale and the related tectonic evolution in China are rather different from those in North America. In China, organic-rich shale is not only deposited in marine environment, but also in non-marine environment: marine-continental transitional environment and lacustrine environment. Through analyzing large amount of outcrops and well cores, the geologic features of organic-rich shale, including mineral composition, organic matter richness and type, and lithology stratigraphy, were analyzed, indicating very special characteristics. Meanwhile, the more complex and active tectonic movements in China lead to strong deformation and erosion of organic-rich shale, well-development of fractures and faults, and higher thermal maturity and serious heterogeneity. Co-existence of shale gas, tight sand gas, and coal bed methane (CBM proposes a new topic: whether it is possible to co-produce these gases to reduce cost. Based on the geologic features, the primary production issues of shale gas in China were discussed with suggestions.

  3. China organic-rich shale geologic features and special shale gas production issues

    Institute of Scientific and Technical Information of China (English)

    Yiwen Ju; Guochang Wang; Hongling Bu; Qingguang Li; Zhifeng Yan

    2014-01-01

    The depositional environment of organic-rich shale and the related tectonic evolution in China are rather different from those in North America. In China, organic-rich shale is not only deposited in marine environment, but also in non-marine environment: marine-continental transitional environment and lacustrine environment. Through analyzing large amount of outcrops and well cores, the geologic fea-tures of organic-rich shale, including mineral composition, organic matter richness and type, and li-thology stratigraphy, were analyzed, indicating very special characteristics. Meanwhile, the more complex and active tectonic movements in China lead to strong deformation and erosion of organic-rich shale, well-development of fractures and faults, and higher thermal maturity and serious heterogeneity. Co-existence of shale gas, tight sand gas, and coal bed methane (CBM) proposes a new topic:whether it is possible to co-produce these gases to reduce cost. Based on the geologic features, the primary pro-duction issues of shale gas in China were discussed with suggestions.

  4. Catalytic hydrogenation of naphthalene through water gas shift reaction in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Okazaki, S.; Kurosawa, S.; Adschiri, T.; Arai, K. [Tohoku University, Sendai (Japan). Dept. of Chemical Engineering

    1998-07-01

    The catalytic hydrogenation of naphthalene through water-gas shift reaction in supercritical water (SCW) was studied with batch experiments. A comparative study of catalytic hydrogenation of naphthalene with NiMo/Al{sub 2}O{sub 3} at 673 K and water density of 0.3 g/cm{sup 3} (30 MPa) was conducted in various atmospheres. Higher conversion of naphthalene to tetralin was obtained in CO-SCW, and H{sub 2}-CO{sub 2}-SCW than in H{sub 2}-SCW. The results clearly indicate that the water-gas shift reaction in SCW produces species which can hydrogenate naphthalene more effectively than H{sub 2} gas in SCW. The effect of water density (0.1-0.5 g/cm{sup 3}) on the hydrogenation in H{sub 2}-SCW and in CO-SCW was also studied. In H{sub 2}-SCW, naphthalene conversion gradually decreased with increasing water density. In CO-SCW, naphthalene conversion first increased and then gradually decreased with increasing water density. 8 refs., 2 figs.

  5. REVIEW OF NATURAL GAS LIQUEFACTION PROCESSES

    OpenAIRE

    2009-01-01

    High pressure pipelines are the most common way of natural gas transport from a gas field to a processing plant and further to consumers. In case when the distance between natural gas production and consumption regions is more than 4000 kilometers, and due to necessity of natural gas supply diversification, gas liquefaction and its transport by ships is being applied. The final choice of liquefaction process depends on the project variables, the development level of new or upgrading of alread...

  6. 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.

  7. The generation of electricity by gas turbines using the catalytic combustion of low-Btu gases

    DEFF Research Database (Denmark)

    Frederiksen, O.P.; Qvale, Einar Bjørn

    1989-01-01

    Various systems for the generation of electricity by gas turbines using catalytic combustion of low-Btu gases have been investigated. Parametric studies of three configurations that are deemed to be practically feasible have been completed. It is shown that thermodynamic efficiency of these systems...... may be quite high. The system design has been made to comply with generally accepted limitations on the operation of the compressors, turbines and heat exchangers. The heat catalyst has been investigated experimentally in order to establish design information. The system design has been carried out on...... the basis of these experiments and of commonly accepted limits on the operation of the compressors, turbines, and heat exchangers...

  8. Removal of nitrogen compounds from gasification gas by selective catalytic or non-catalytic oxidation; Typpiyhdisteiden poisto kaasutuskaasusta selektiivisellae katalyyttisellae ja ei-katalyyttisellae hapetuksella

    Energy Technology Data Exchange (ETDEWEB)

    Leppaelahti, J.; Koljonen, T. [VTT Energy, Espoo (Finland)

    1996-12-01

    In gasification reactive nitrogenous compounds are formed from fuel nitrogen, which may form nitrogen oxides in gas combustion. In fluidized bed gasification the most important nitrogenous compound is ammonia (NH{sub 3}). If ammonia could be decomposed to N{sub 2} already before combustion, the emissions if nitrogen oxides could be reduced significantly. One way of increasing the decomposition rate of NH{sub 3} could be the addition of suitable reactants to the gas, which would react with NH{sub 3} and produce N{sub 2}. The aim of this research is to create basic information, which can be used to develop a new method for removal of nitrogen compounds from gasification gas. The reactions of nitrogen compounds and added reactants are studied in reductive atmosphere in order to find conditions, in which nitrogen compounds can be oxidized selectively to N{sub 2}. The project consists of following subtasks: (1) Selective non-catalytic oxidation (SNCO): Reactions of nitrogen compounds and oxidizers in the gas phase, (2) Selective catalytic oxidation (SCO): Reactions of nitrogen compounds and oxidizers on catalytically active surfaces, (3) Kinetic modelling of experimental results in co-operation with the Combustion Chemistry Research Group of Aabo Akademi University. The most important finding has been that NH{sub 3} can be made to react selectively with the oxidizers even in the presence of large amounts of CO and H{sub 2}. Aluminium oxides were found to be the most effective materials promoting selectivity. (author)

  9. Some peculiarities of adsorption and catalytic processes on solid solutions of diamond-like semiconductors

    International Nuclear Information System (INIS)

    The results of adsorption and catalytic process investigations in some systems ZnSe-ZnTe, ZnSe-CdSe; ZnSe-GaAs are analyzed. Identity and specific peculiarities in the behaviour of adsorbent solid solutions and catalysts are marked in comparison with the binary semiconductors. The dependence of adsorption value and catalytic activity on the composition has non-additive character. Some definite private dependences between the changes of adsorption-catalytic and physical parameters and the composition are found. The comparative data are obtained on the adsorption and catalytic activity of solid solutions of different systems. The last ones are explained with an account of nonsimilar defectiveness of the systems and property changes of active centers during formation process of solid solutions. The optimum catalyst is found

  10. Exxon catalytic coal gasification process development program. Quarterly technical progress report, January 1-March 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    1979-05-01

    This report covers the activites for the Exxon Catalytic Coal Gasification Development Program during the quarter January 1-March 31, 1979. Construction of a bench apparatus to study reactions of product and recycle gas in furnace and heat exchanger tubes was completed and checkout of the apparatus was begun. A Startup and Initial Operation Schedule, a Checkout Test Plan, and an Initial Startup Plan were developed for the Process Develoment Unit (PDU). The PDU will be started up in a sequential manner, with the gasification system being started up on a once-through basis first. The gas separation system will be started up next, followed by the catalyst recovery system. The programmable controller, which handles valve sequencing, alarming, and other miscellaneous functions on the PDU, was programmed and checkout was completed on the coal feed, gas feed, and filter systems. Work continued on defining the cause of the breakdown of char and lime during digestion in the prototype catalyst recovery unit. It was concluded that both the lime and char particles are fragile and will break down to fines if handled roughly. Removal of the potassium from the char by water washing does not cause the char particles to disintegrate. The perferred processing sequence for catalyst recovery in the PDU has been identified. Bench scale tests confirmed that the change in catalyst from K/sub 2/CO/sub 3/ to KOH was not responsible for the differences in fluidized bed densities between the present and the predevelopment operations of the FBG. Work was completed on a revised offsites facilities definition and cost estimate to update the CCG Commercial Plant Study Design prepared during the predevelopment program.

  11. Gas turbines for polygeneration? A thermodynamic investigation of a fuel rich gas turbine cycle

    Directory of Open Access Journals (Sweden)

    Burak Atakan

    2011-11-01

    ="EN-US">For stationary conditions a different approach may be worth a second thought: the use of gas turbines as chemical reactors for hydrogen and carbon monoxide production in combination with power generation and the utilization of the exhaust enthalpy stream. A gas turbine model cycle is analyzed using complex equilibria including radicals and chemical exergies. Chemical exergies were calculated from equilibrating the gas mixtures at different points in each process with a large excess of moist air. Methane was studied as an exemplary fuel.

    Comparing the exergy losses of the idealized gas turbine process, the losses for the fuel rich stoichiometry are lower than at the lean stoichiometry used in gas turbines nowadays. The exact values of the exergetic efficiency depend on the pressure ratio, which was studied in the range of 10 to 30. The hydrogen to carbon monoxide ratio would be typically near 2.2, while the adiabatic flame temperature would be in a range which either would cause no damage to typical gas turbines or could be handled with carbon fiber reinforced carbon. The composition of the gases is likely to change within the turbine, where temperature and enthalpy drops. This was considered in additional calculations where chemical equilibration of the gas mixture in the turbine is considered. The possibility to combine a partial oxidation with an energy conversion process and thus produce syngas mixtures would add an additional flexibility to the gas turbine process, which is worth consideration.

  12. Interactions Between Surface Reactions and Gas-phase Reactions in Catalytic Combustion and Their Influence on Ignition of HCCI Engine

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The catalytic combustion of methane in a microchannel whose surface was coated with platinum(Pt)catalyst was studied by numerical-simulation. The effects of gas-phase reactions on the whole catalytic combustion process were analyzed at a high inlet pressure. A sensitivity analysis of the detailed mechanisms of the surface reaction of methane on Pt revealed that the most sensitive reactions affecting the heterogeneous ignition are oxygen adsorption/desorption and methane adsorption, and the most sensitive reactions affecting the homogeneous ignition are OH and H2O adsorption/desorption. The combustion process of the homogeneous charge compression ignition(HCCI) engine whose piston face was coated with Pt catalyst was simulated. The effects of catalysis and the most sensitive reactions on the ignition timing and the concentration of the main intermediate species during the HCCI engine combustion are discussed. The results show that the ignition timing of the HCCI engine can be increased by catalysis, and the most sensitive reactions affecting the ignition timing of the HCCI engine are OH and H2O adsorption/desorption.

  13. Lean-rich axial stage combustion in a can-annular gas turbine engine

    Science.gov (United States)

    Laster, Walter R.; Szedlacsek, Peter

    2016-06-14

    An apparatus and method for lean/rich combustion in a gas turbine engine (10), which includes a combustor (12), a transition (14) and a combustor extender (16) that is positioned between the combustor (12) and the transition (14) to connect the combustor (12) to the transition (14). Openings (18) are formed along an outer surface (20) of the combustor extender (16). The gas turbine (10) also includes a fuel manifold (28) to extend along the outer surface (20) of the combustor extender (16), with fuel nozzles (30) to align with the respective openings (18). A method (200) for axial stage combustion in the gas turbine engine (10) is also presented.

  14. Tritiated water processing using liquid phase catalytic exchange and solid oxide electrolyte cell

    International Nuclear Information System (INIS)

    Liquid phase catalytic exchange (LPCE) is an effective method for enrichment and removal of tritium from tritiated water. Combined electrolysis catalytic exchange (CECE) process is an attractive application of a LPCE column. We proposed a new process that improves the CECE process. Using a solid oxide electrolyte (SOE) cell for electrolysis makes the CECE process more energy efficient and eliminates other disadvantages such as large tritium inventory and extremely slow system response. When the cell is used for recombination, the system becomes even more simple, efficiently, reliable and safe. 21 refs., 9 figs

  15. Analysis of catalytic gas products using electron energy-loss spectroscopy and residual gas analysis for operando transmission electron microscopy.

    Science.gov (United States)

    Miller, Benjamin K; Crozier, Peter A

    2014-06-01

    Operando transmission electron microscopy (TEM) of catalytic reactions requires that the gas composition inside the TEM be known during the in situ reaction. Two techniques for measuring gas composition inside the environmental TEM are described and compared here. First, electron energy-loss spectroscopy, both in the low-loss and core-loss regions of the spectrum was utilized. The data were quantified using a linear combination of reference spectra from individual gasses to fit a mixture spectrum. Mass spectrometry using a residual gas analyzer was also used to quantify the gas inside the environmental cell. Both electron energy-loss spectroscopy and residual gas analysis were applied simultaneously to a known 50/50 mixture of CO and CO2, so the results from the two techniques could be compared and evaluated. An operando TEM experiment was performed using a Ru catalyst supported on silica spheres and loaded into the TEM on a specially developed porous pellet TEM sample. Both techniques were used to monitor the conversion of CO to CO2 over the catalyst, while simultaneous atomic resolution imaging of the catalyst was performed. PMID:24815065

  16. Synthesis of carbon nanbotubes by plasma-enhanced CVD process: gas phase study of synthesis conditions

    Science.gov (United States)

    Guláš, M.; Cojocaru, C. S.; Fleaca, C. T.; Farhat, S.; Veis, P.; Le Normand, F.

    2008-09-01

    To support experimental investigations, a model based on Chemkin^TM software was used to simulate gas phase and surface chemistry during plasma-enhanced catalytic CVD of carbon nanotubes. According to these calculations, gas phase composition, etching process and growth rates are calculated. The role of several carbon species, hydrocarbon molecules and ions in the growth mechanism of carbon nanotubes is presented in this study. Study of different conditions of gas phase activation sources and pressure is performed.

  17. Tungsten inert gas (TIG) welding of Ni-rich NiTi plates: functional behavior

    Science.gov (United States)

    Oliveira, J. P.; Barbosa, D.; Braz Fernandes, F. M.; Miranda, R. M.

    2016-03-01

    It is often reported that, to successfully join NiTi shape memory alloys, fusion-based processes with reduced thermal affected regions (as in laser welding) are required. This paper describes an experimental study performed on the tungsten inert gas (TIG) welding of 1.5 mm thick plates of Ni-rich NiTi. The functional behavior of the joints was assessed. The superelasticity was analyzed by cycling tests at maximum imposed strains of 4, 8 and 12% and for a total of 600 cycles, without rupture. The superelastic plateau was observed, in the stress-strain curves, 30 MPa below that of the base material. Shape-memory effect was evidenced by bending tests with full recovery of the initial shape of the welded joints. In parallel, uniaxial tensile tests of the joints showed a tensile strength of 700 MPa and an elongation to rupture of 20%. The elongation is the highest reported for fusion-welding of NiTi, including laser welding. These results can be of great interest for the wide-spread inclusion of NiTi in complex shaped components requiring welding, since TIG is not an expensive process and is simple to operate and implement in industrial environments.

  18. Hydrogen rich gas from oil palm biomass as a potential source of renewable energy in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed, M.A.A.; Salmiaton, A.; Wan Azlina, W.A.K.G.; Mohammad Amran, M.S.; Fakhru' l-Razi, A. [Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Taufiq-Yap, Y.H. [Centre of Excellence for Catalysis Science and Technology and Department of Chemistry, Faculty of Science, University Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2011-02-15

    Oil palm is one of the major economic crops in many countries. Malaysia alone produces about 47% of the world's palm oil supply and can be considered as the world's largest producer and exporter of palm oil. Malaysia also generates huge quantity of oil palm biomass including oil palm trunks, oil palm fronds, empty fruit bunches (EFB), shells and fibers as waste from palm oil fruit harvest and oil extraction processing. At present there is a continuously increasing interest in the utilization of oil palm biomass as a source of clean energy. One of the major interests is hydrogen from oil palm biomass. Hydrogen from biomass is a clean and efficient energy source and is expected to take a significant role in future energy demand due to the raw material availability. This paper presents a review which focuses on different types of thermo-chemical processes for conversion of oil palm biomass to hydrogen rich gas. This paper offers a concise and up-to-date scenario of the present status of oil palm industry in contributing towards sustainable and renewable energy. (author)

  19. Catalytic cracking of tar in biomass pyrolysis gas in the presence of calcined dolomite

    International Nuclear Information System (INIS)

    The possibility of decreasing the tar content of the fuel gas obtained by biomass pyrolysis was studied. Pyrolysis of mixed hardwood chips was carried out in a laboratory-scale cracking reactor using a dolomite catalyst, which showed a high catalytic activity. The effects of reaction variables such as temperature, and amount of catalyst and steam, were studied. The overall effect of the dolomite is to increase the gas yield by decreasing the tar yield. The dolomite and the steam used seem to affect the amount of naphthalene produced. By adjusting both the amounts of catalyst and steam, the amounts of naphthalene (13 mg/kg of dry biomass) and tar (164 mg/kg) were decreased significantly. The yields of hydrogen, CO and CO2 depended on the steam to biomass weight ratio in the range of 0 to 0.6 kg/kg. 18 refs., 8 figs., 5 tabs

  20. Design and experimentation with sandwich microstructure for catalytic combustion-type gas sensors.

    Science.gov (United States)

    Gu, Jun-Tao; Zhang, Yong-De; Jiang, Jin-Gang

    2014-01-01

    The traditional handmade catalytic combustion gas sensor has some problems such as a pairing difficulty, poor consistency, high power consumption, and not being interchangeable. To address these issues, integrated double catalytic combustion of alcohol gas sensor was designed and manufactured using silicon micro-electro-mechanical systems (MEMS) technology. The temperature field of the sensor is analyzed using the ANSYS finite element analysis method. In this work, the silicon oxide-PECVD-oxidation technique is used to manufacture a SiO2-Si3N2-SiO2 microstructure carrier with a sandwich structure, while wet etching silicon is used to form a beam structure to reduce the heat consumption. Thin-film technology is adopted to manufacture the platinum-film sensitive resistance. Nano Al2O3-ZrO-ThO is coated to format the sensor carrier, and the sensitive unit is dipped in a Pt-Pd catalyst solution to form the catalytic sensitive bridge arm. Meanwhile the uncoated catalyst carrier is considered as the reference unit, realizing an integrated chip based on a micro double bridge and forming sensors. The lines of the Pt thin-film resistance have been observed with an electronic microscope. The compensation of the sensitive material carriers and compensation materials have been analyzed using an energy spectrum. The results show that the alcohol sensor can detect a volume fraction between 0 and 4,500 × 10(-6) and has good linear output characteristic. The temperature ranges from -20 to +40 °C. The humidity ranges from 30% to 85% RH. The zero output of the sensor is less than ±2.0% FS. The power consumption is ≤0.2 W, and both the response and recovery time are approximately 20 s. PMID:24625742

  1. Design and Experimentation with Sandwich Microstructure for Catalytic Combustion-Type Gas Sensors

    Directory of Open Access Journals (Sweden)

    Jun-Tao Gu

    2014-03-01

    Full Text Available The traditional handmade catalytic combustion gas sensor has some problems such as a pairing difficulty, poor consistency, high power consumption, and not being interchangeable. To address these issues, integrated double catalytic combustion of alcohol gas sensor was designed and manufactured using silicon micro-electro-mechanical systems (MEMS technology. The temperature field of the sensor is analyzed using the ANSYS finite element analysis method. In this work, the silicon oxide-PECVD-oxidation technique is used to manufacture a SiO2-Si3N2-SiO2 microstructure carrier with a sandwich structure, while wet etching silicon is used to form a beam structure to reduce the heat consumption. Thin-film technology is adopted to manufacture the platinum-film sensitive resistance. Nano Al2O3-ZrO-ThO is coated to format the sensor carrier, and the sensitive unit is dipped in a Pt-Pd catalyst solution to form the catalytic sensitive bridge arm. Meanwhile the uncoated catalyst carrier is considered as the reference unit, realizing an integrated chip based on a micro double bridge and forming sensors. The lines of the Pt thin-film resistance have been observed with an electronic microscope. The compensation of the sensitive material carriers and compensation materials have been analyzed using an energy spectrum. The results show that the alcohol sensor can detect a volume fraction between 0 and 4,500 × 10−6 and has good linear output characteristic. The temperature ranges from −20 to +40 °C. The humidity ranges from 30% to 85% RH. The zero output of the sensor is less than ±2.0% FS. The power consumption is ≤0.2 W, and both the response and recovery time are approximately 20 s.

  2. Investigation of a catalytic gas generator for the Space Shuttle APU. [hydrazine Auxiliary Propulsion Unit

    Science.gov (United States)

    Emmons, D. L.; Huxtable, D. D.; Blevins, D. R.

    1974-01-01

    An investigation was conducted to establish the capability of a monopropellant hydrazine catalytic gas generator to meet the requirements specified for the Space Shuttle APU. Detailed analytical and experimental studies were conducted on potential problem areas including long-term nitriding effects on materials, design variables affecting catalyst life, vehicle vibration effects, and catalyst oxidation/contamination. A full-scale gas generator, designed to operate at a chamber pressure of 750 psia and a flow rate of 0.36 lbm/sec, was fabricated and subjected to three separate life test series. The objective of the first test series was to demonstrate the capability of the gas generator to successfully complete 20 simulated Space Shuttle missions in steady-state operation. The gas generator was then refurbished and subjected to a second series of tests to demonstrate the pulse-mode capability of the gas generator during 20 simulated missions. The third series of tests was conducted with a refurbished reactor to further demonstrate pulse-mode capability with a modified catalyst bed.

  3. Catalytic behaviors of ruthenium dioxide films deposited on ferroelectrics substrates, by spin coating process

    International Nuclear Information System (INIS)

    Catalytic ruthenium dioxide films were deposited by spin-coating process on ferroelectric films mainly constituted of SrBi2Ta2O9 (SBT) and Ba2NaNb5O15 (BNN) phases. After thermal treatment under air, these ferroelectric-catalytic systems were characterized by X-ray diffraction and scanning electron microscopy (SEM). SEM images showed that RuO2 film morphology depended on substrate nature. A study of CH4 conversion into CO2 and H2O was carried out using these catalytic-ferroelectric multilayers: the conversion was analyzed from Fourier transform infrared (FTIR) spectroscopy, at various temperatures. Improved catalytic properties were observed for RuO2 films deposited on BNN oxide layer

  4. Synthesis, crystallization mechanism, and catalytic properties of titanium-rich TS-1 free of extraframework titanium species.

    Science.gov (United States)

    Fan, Weibin; Duan, Ren-Guan; Yokoi, Toshiyuki; Wu, Peng; Kubota, Yoshihiro; Tatsumi, Takashi

    2008-08-01

    the method A system most of Ti cations was inserted into the lattice after the crystallization was nearly completed, the inclusion of Ti started at the earlier nucleation period in the presence of (NH4)2CO3. This is favorable for the incorporation of Ti into the framework, resulting in a more homogeneous distribution of Ti in the framework. Oxidation of 1-hexene and 2-hexanol over the samples collected during the whole crystallization process indicated that condensation of Ti-OH and Si-OH proceeded even after the crystallization was completed. This resulted in an increase in hydrophobicity and an overall improvement in microscopic character of Ti species and consequently a great increase in the catalytic activity with further progress of crystallization. PMID:18613685

  5. Theoretical study of catalytic efficiency of a Diels-Alderase catalytic antibody: an indirect effect produced during the maturation process.

    Science.gov (United States)

    Martí, Sergio; Andrés, Juan; Moliner, Vicent; Silla, Estanislao; Tuñón, Iñaki; Bertrán, Juan

    2008-01-01

    The Diels-Alder reaction is one of the most important and versatile transformations available to organic chemists for the construction of complex natural products, therapeutics agents, and synthetic materials. Given the lack of efficient enzymes capable of catalyzing this kind of reaction, it is of interest to ask whether a biological catalyst could be designed from an antibody-combining site. In the present work, a theoretical study of the different behavior of a germline catalytic antibody (CA) and its matured form, 39 A-11, that catalyze a Diels-Alder reaction has been carried out. A free-energy perturbation technique based on a hybrid quantum-mechanics/molecular-mechanics scheme, together with internal energy minimizations, has allowed free-energy profiles to be obtained for both CAs. The profiles show a smaller barrier for the matured form, which is in agreement with the experimental observation. Free-energy profiles were obtained with this methodology, thereby avoiding the much more demanding two-dimensional calculations of the energy surfaces that are normally required to study this kind of reaction. Structural analysis and energy evaluations of substrate-protein interactions have been performed from averaged structures, which allows understanding of how the single mutations carried out during the maturation process can be responsible for the observed fourfold enhancement of the catalytic rate constant. The conclusion is that the mutation effect in this studied germline CA produces a complex indirect effect through coupled movements of the backbone of the protein and the substrate. PMID:17960540

  6. Discharge Processes in Gas Lasers

    International Nuclear Information System (INIS)

    A review is given of the contemporary knowledge of some important discharge processes occurring in gas discharge lasers. The classification of gas lasers in terms of gaseous species, pumping mechanisms and discharge geometries allows convenient discussion of their general properties. With emphasis on the associated discharge properties, the different methods to obtain population inversion are considered. Included are the discharge processes involved in (1) direct excitation, (2) resonant energy transfer, (3) optical pumping, (4) adiabatic expansion and (5) chemical pumping. The last grouping includes the achievement of a population inversion by way of dissociation or photodissociation, oxidation and recombination or charge transfer. The diagnostic techniques applied to the present three principal lasers: the helium-neon, the argon ion and the CO2-N2 lasers, are considered in some detail. For the He-Ne laser the diagnostic techniques of spontaneous sidelight observations and of ''laser perturbation spectroscopy'' are described. The sidelight observations give data on relative population changes of excited states. Metastable atom densities are obtained by means of absorption measurements. An external spoiling or modulation of the lasering action may be used as a defined perturbation of the laser levels. Using phase-sensitive detection, these population perturbations may be followed as they are distributed by radiative cascade to allowed lower levels. The modulations of higher level excited state populations and of the discharge current allows estimations of cumulative ionization and excitation, while the degree of applicability of any radiative-collisional decay model can be checked by detailed balancing of the distribution of the modulated populations. These data, together with a knowledge of the properties of the optical cavity, allows an estimation of the excitation rates and cross-sections involved, including collisions with excited atoms (information which is

  7. Gas prices and price process

    International Nuclear Information System (INIS)

    On a conference (Gas for Europe in the 1990's) during the Gasexpo '91 the author held a speech of which the Dutch text is presented here. Attention is paid to the current European pricing methods (prices based on the costs of buying, transporting and distributing the natural gas and prices based on the market value, which is deducted from the prices of alternative fuels), and the transparency of the prices (lack of information on the way the prices are determined). Also attention is paid to the market signal transparency and gas-gas competition, which means a more or less free market of gas distribution. The risks of gas-to-gas competition for a long term price stability, investment policies and security of supply are discussed. Opposition against the Third Party Access (TPA), which is the program to implement gas-to-gas competition, is caused by the fear of natural gas companies for lower gas prices and lower profits. Finally attention is paid to government regulation and the activities of the European Commission (EC) in this matter. 1 fig., 6 ills., 1 tab

  8. Organic richness and gas generation potential of Permian Barren Measures from Raniganj field, West Bengal, India

    Science.gov (United States)

    Boruah, Annapurna; Ganapathi, S.

    2015-07-01

    The organic geochemistry of shales in terms of its organic richness, hydrocarbon source potential, thermal maturity, depositional environment, etc., are essential stipulations for shale gas resources assessment. In this study, a total of 32 core samples of Permian Barren Measures from four boreholes in Raniganj field of Damodar Basin were analysed to evaluate their gas generation potential using Rock-Eval pyrolysis techniques. Petrographic analysis brings out the lithofacies of Barren Measures as carbonaceous silty shale, iron rich claystone and sand-shale intercalation. The total organic content (TOC) of the shale units of Barren Measures ranges from 3.75 to 20.9 wt%, whereas hydrogen index (HI) ranges from 58.45 to 125.34 mg HC/g TOC. Present study suggests early to late maturated (0.6-1%) organic matters in Barren Measures with gas prone type III kerogen. The study analysed the effect of burial history on the preservation and maturation of organic matters. The organic richness, kerogen type, thermal maturity and petrographic properties of Barren Measures signify fair to excellent gas generation potential.

  9. Organic richness and gas generation potential of Permian Barren Measures from Raniganj field, West Bengal, India

    Indian Academy of Sciences (India)

    Annapurna Boruah; S Ganapathi

    2015-07-01

    The organic geochemistry of shales in terms of its organic richness, hydrocarbon source potential, thermal maturity, depositional environment, etc., are essential stipulations for shale gas resources assessment. In this study, a total of 32 core samples of Permian Barren Measures from four boreholes in Raniganj field of Damodar Basin were analysed to evaluate their gas generation potential using Rock–Eval pyrolysis techniques. Petrographic analysis brings out the lithofacies of Barren Measures as carbonaceous silty shale, iron rich claystone and sand-shale intercalation. The total organic content (TOC) of the shale units of Barren Measures ranges from 3.75 to 20.9 wt%, whereas hydrogen index (HI) ranges from 58.45 to 125.34 mg HC/g TOC. Present study suggests early to late maturated (0.6–1%) organic matters in Barren Measures with gas prone type III kerogen. The study analysed the effect of burial history on the preservation and maturation of organic matters. The organic richness, kerogen type, thermal maturity and petrographic properties of Barren Measures signify fair to excellent gas generation potential.

  10. Catalytic Steam Reforming of Bio-Oil to Hydrogen Rich Gas

    OpenAIRE

    Trane-Restrup, Rasmus; Jensen, Anker Degn; Dahl, Søren

    2013-01-01

    Bio-oil is a liquid produced by pyrolysis of biomass and its main advantage compared with biomass is an up to ten times higher energy density. This entails lower transportation costs associated with the utilization of biomass for production of energy and fuels. Nevertheless, the bio-oil has a low heating value and high content of oxygen, which makes it unsuited for direct utilization in engines. One prospective technology for upgrading of bio-oil is steam reforming(SR), which can be used to p...

  11. Catalytic Steam Reforming of Bio-Oil to Hydrogen Rich Gas

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus

    the Fischer-Tropsch synthesis. In the SR of bio-oil or biooil model compounds high degrees of conversion and high yields of H2 can be achieved, but stability with time-on-stream is rarely achieved. The deactivation is mainly due to carbon deposition and is one of the major hurdles in the SR of bio...... at 600 ‰ over Ni-K/MgAl2O4 and Ni/K-CeO2/MgAl2O4 both showed deactivation with time-on-stream mainly due to carbon deposition as carbon whiskers. Sulfur was added as K2SO4 to Ni-CeO2/MgAl2O4 to selectively poison Ni-sites and inhibit carbon deposition. The sulfur poisoning induced a decrease...... as the carbon deposition. Carbon deposition was almost eliminated at an O/C-ratio of approximately 0.8. The penalty of adding O2 was a decrease in the yield of H2 corresponding to loss of 1 mole of H2 pr. mole of ethanol converted compared with SR without O2. H2-addition had little inuence on the catalyst...

  12. Gas explosions in process pipes

    OpenAIRE

    Kristoffersen, Kjetil

    2004-01-01

    In this thesis, gas explosions inside pipes are considered. Laboratory experiments and numerical simulations are the basis of the thesis. The target of the work was to study gas explosions in pipes and to develop numer- ical models that could predict accidental gas explosions inside pipes. Experiments were performed in circular steel and plexiglass pipes. The steel pipes have an inner diameter of 22.3 mm and lengths of 1, 2, 5 and 11 m. The plexiglass pipe has an inner diame...

  13. Effects of inert species in the gas phase in a model for the catalytic oxidation of CO

    CERN Document Server

    Buendia, G M

    2011-01-01

    We study by kinetic Monte Carlo simulations the catalytic oxidation of carbon monoxide on a surface in the presence of contaminants in the gas phase. The process is simulated by a Ziff-Gulari-Barshad (ZGB) model that has been modified to include the effect of the contaminants and to eliminate the unphysical oxygen-poisoned phase. The impurities can adsorb and desorb on the surface, but otherwise remain inert. We find that, if the impurities can not desorb, no matter how small their proportion in the gas mixture, the first order transition and the reactive window that characterize the ZGB model disappear. The coverages become continuous, and once the surface has reached a steady state there is no production of CO$_2$. This is quite different from the behavior of a system in which the surface presents a fixed percentage of impurities. When the contaminants are allowed to desorb, the reactive window appears again, and disappears at a value that depends on the proportion of contaminants in the gas and on their de...

  14. A Novel miRNA Processing Pathway Independent of Dicer Requires Argonaute2 Catalytic Activity

    OpenAIRE

    Cifuentes, Daniel; Xue, Huiling; Taylor, David W.; Patnode, Heather; Mishima, Yuichiro; Cheloufi, Sihem; Ma, Enbo; Mane, Shrikant; Hannon, Gregory J.; Lawson, Nathan D.; Wolfe, Scot A.; Giraldez, Antonio J.

    2010-01-01

    Dicer is a central enzyme in microRNA (miRNA) processing. We identified a Dicer-independent miRNA biogenesis pathway that uses Argonaute2 (Ago2) slicer catalytic activity. In contrast to other miRNAs, miR-451 levels were refractory to dicer loss of function but were reduced in MZago2 (maternal-zygotic) mutants. We found that pre-miR-451 processing requires Ago2 catalytic activity in vivo. MZago2 mutants showed delayed erythropoiesis that could be rescued by wild-type Ago2 or miR-451-duplex bu...

  15. Advanced catalytic plasma exhaust clean-up process for ITER-EDA

    Energy Technology Data Exchange (ETDEWEB)

    Glugla, M. [Kernforschungszentrum Karlsruhe, Inst. fuer Radiochemie (Germany); Penzhorn, R.D. [Kernforschungszentrum Karlsruhe, Inst. fuer Radiochemie (Germany); Hermann, P. [Kernforschungszentrum Karlsruhe, Inst. fuer Radiochemie (Germany); Ache, H.J. [Kernforschungszentrum Karlsruhe, Inst. fuer Radiochemie (Germany)

    1995-12-31

    A new catalyst reactor (PERMCAT) has been developed to further improve the catalytic conversion / permeation based plasma exhaust clean-up process realized in the facility CAPRICE at the Tritium Laboratory Karlsruhe (TLK). The reactor directly combines a nickel catalyst with permeation tubes and removes residual amounts of tritium from tritiated species by isotopic swamping with hydrogen. Succesful integration of such a unit into the CAPRICE catalytic clean-up approach could lead to a fully continuous process and bring about a considerable reduction in non-recoverable tritium. (orig.).

  16. Advanced catalytic plasma exhaust clean-up process for ITER-EDA

    International Nuclear Information System (INIS)

    A new catalyst reactor (PERMCAT) has been developed to further improve the catalytic conversion / permeation based plasma exhaust clean-up process realized in the facility CAPRICE at the Tritium Laboratory Karlsruhe (TLK). The reactor directly combines a nickel catalyst with permeation tubes and removes residual amounts of tritium from tritiated species by isotopic swamping with hydrogen. Succesful integration of such a unit into the CAPRICE catalytic clean-up approach could lead to a fully continuous process and bring about a considerable reduction in non-recoverable tritium. (orig.)

  17. PENGARUH KATALIS Co DAN Fe TERHADAP KARAKTERISTIK CARBON NANOTUBES DARI GAS ASETILENA DENGAN MENGGUNAKAN PROSES CATALYTIC CHEMICAL VAPOUR DEPOSITION (CCVD

    Directory of Open Access Journals (Sweden)

    Tutuk Djoko Kusworo

    2013-11-01

    Full Text Available EFFECT OF Co AND Fe ON CARBON NANOTUBES CHARACTERISTICS FROM ACETYLENE USING CATALYTIC CHEMICAL VAPOUR DEPOSITION (CCVD PROCESS. Carbon Nanotubes (CNTs is one of the most well known nano-technology applications which the most of attracting the attention of researchers, because it has more advantages than other materials. The application of the CNT has extended into various aspects, such as electronics, materials, biology and chemistry. This research uses a system of Catalytic Chemical Vapour Deposition (CCVD, which aims to determine the influence of Co and Fe as a catalyst and zeolite 4A as a support catalyst with acetylene gas (C2H2 as carbon source in the synthesis of Carbon Nanotubes (CNTs. In this experiment, used the ratio of acetylene gas and flow rate of N2 gas is 1:1 by weight of the catalyst Co/Zeolite and Fe/Zeolite amounted to 0.5 grams at the operating temperature of 700oC for 20 minutes. N2 gas serves to minimize the occurrence of oxidation reaction (explosion when operating. From analysis result by Scanning Electron Microscopy (SEM shows the CNTs formed a type of MWNT with different of diameter size and product weight, depending on the size of the active component concentration on the catalyst. The larger of active components produced CNTs with larger diameter, whereas product weight syntheses result smaller. Use of the catalyst Fe/Zeolite produce CNTs with a diameter larger than the catalyst Co/Zeolite.  Carbon Nanotubes (CNTs merupakan salah satu aplikasi nanoteknologi yang paling terkenal dan banyak menarik perhatian para peneliti, karena memiliki beberapa kelebihan daripada material lainnya. Aplikasi dari CNT telah merambah ke berbagai aspek, seperti bidang elektronika, material, biologi dan kimia. Penelitian ini menggunakan sistem Catalytic Chemical Vapour Deposition (CCVD yang bertujuan untuk mengetahui pengaruh variasi Cobalt (Co dan Ferrum (Fe sebagai katalis dan zeolit tipe 4A sebagai penyangga katalis dengan gas

  18. Catalytic hydrothermal gasification of biomass for the production of synthetic natural gas[Dissertation 17100

    Energy Technology Data Exchange (ETDEWEB)

    Waldner, M. H.

    2007-07-01

    Energy from biomass is a CO{sub 2} neutral, sustainable form of energy. Anaerobic digestion is an established technology for converting biomass to biogas, which contains around 60% methane, besides CO{sub 2} and various contaminants. Most types of biomass contain material that cannot be digested; in woody biomass, this portion is particularly high. Therefore, conventional anaerobic digestion is not suited for the production of biogas from woody biomass. While wood is already being converted to energy by conventional thermal methods (gasification with subsequent methanation), dung, manure, and sewage sludge represent types of biomass whose energy potential remains largely untapped (present energetic use of manure in Switzerland: 0.4%). Conventional gas phase processes suffer from a low efficiency due to the high water content of the feed (enthalpy of vaporization). An alternative technology is the hydrothermal gasification: the water contained within the biomass serves as reaction medium, which at high pressures of around 30 MPa turns into a supercritical fluid that exhibits apolar properties. Under these conditions, tar precursors, which cause significant problems in conventional gasification, can be solubilized and gasified. The need to dry the biomass prior to gasification is obsolete, and as a consequence high thermal process efficiencies (65 - 70%) are possible. Due to their low solubility in supercritical water, the inorganics that are present in the biomass (up to 20 wt % of the dry matter of manure) can be separated and further used as fertilizer. The biomass is thus not only converted into an energy carrier, but it allows valuable substances contained in the biomass to be extracted and re-used. Furthermore, the process can be used for aqueous waste stream destruction. The aim of this project at the Paul Scherrer Institute was to develop a catalytic process that demonstrates the gasification of wet biomass to synthetic natural gas (SNG) in a continuously

  19. Hydrogen production by Thermo Catalytic Decomposition of Natural Gas: Ni-based catalysts

    International Nuclear Information System (INIS)

    Thermo Catalytic Decomposition of methane using Ni and Ni-Cu catalyst is studied. The conventional co-precipitation method is compared versus an easier preparation method based on the fusing of the metallic nitrates. The role of copper has also been analyzed. TCD has been carried out in a bench scale fixed bed and a semi-pilot scale fluidized bed. Catalysts prepared by both methods shown similar behaviour. Introduction of copper in the catalyst promoted NiO reduction which prevented hydrogen from CO contamination. Fluid-dynamic studies have shown that TCD can be carried out in a fluidized bed reactor without reactor clogging provided that a methane velocity of two times the minimum fluidization velocity is used. This high spatial velocity resulted in a reduction of methane conversion. So the optimum gas velocity should be chosen in terms of hydrogen production rates and fluidization quality. (authors)

  20. Control of gaseous pollutants emission with EGR (exhaust gas recirculation) and catalytic converter

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Fernando Silva de Araujo [Faculdade de Engenharia Quimica de Lorena (FAENQUIL), SP (Brazil); Mann, Jens; Ueberschaer, Dietmar [Fachhochschule Darmstadt (Germany). Fachbereich Maschinenbau; Balestieri, Jose Antonio Perrella; Nascimento, Nazem [UNESP, Guaratingueta, SP (Brazil). Faculdade de Engenharia]. E-mail: ftilor@eu.ansp.br; perrella@feg.unesp.br; nazem@feg.unesp.br

    1997-07-01

    Study of gaseous pollutant emission from engine tests simulating real work conditions, using spark point manually controlled and exhaust gas recirculation in diverse proportion levels. The objective of this present work is to re-examine the potential of the EGR conception, a well-known method of combustion control, employed together electronic fuel injection and three-way catalytic converter closed-loop control at a spark ignition engine, verifying the performance characteristics and technical availability of this conception to improve pollution control and fuel economy. The pollutant emissions under operational conditions were analyzed and compared with the expected by concerning theory and real tests performed by EGR equipped engines by factory. (author)

  1. Filtering suspension e.g. gas from nuclear reactor etc. by separating some of its solids, passing it through filter and recycling fraction rich in solids

    International Nuclear Information System (INIS)

    Gas or liquid contaminated by radioactive particles are filtered for extraction of a part of the purified fluid, a part of particles in the fluid are extracted by a cyclone separator or an electrostatic filter; this fluid poor in particles or the fluid rich in particles from the filtration is recycled after addition of the initial fluid. The process avoid filter clogging

  2. Radioactive waste gas processing systems

    International Nuclear Information System (INIS)

    Purpose: To effectively separate and remove only hydrogen from hydrogen gas-containing radioactive waste gases produced from nuclear power plants without using large scaled facilities. Constitution: From hydrogen gas-enriched waste gases which contain radioactive rare gases (Kr, Xe) sent from the volume control tank of a chemical volume control system, only the hydrogen is separated in a hydrogen separator using palladium alloy membrane and rare gases are concentrated, volume-decreased and then stored. In this case, an activated carbon adsorption device is connected at its inlet to the radioactive gas outlet of the hydrogen separator and opened at its outlet to external atmosphere. In this system, while only the hydrogen gas permeates through the palladium alloy membrane, other gases are introduced, without permeation, into the activated carbon adsorption device. Then, the radioactive rare gases are decayed by the adsorption on the activated carbon and then released to the external atmosphere. (Furukawa, Y.)

  3. Quantifying Hydrate Formation in Gas-rich Environments Using the Method of Characteristics

    Science.gov (United States)

    You, K.; Flemings, P. B.; DiCarlo, D. A.

    2015-12-01

    Methane hydrates hold a vast amount of methane globally, and have huge energy potential. Methane hydrates in gas-rich environments are the most promising production targets. We develop a one-dimensional analytical solution based on the method of characteristics to explore hydrate formation in such environments (Figure 1). Our solution shows that hydrate saturation is constant with time and space in a homogeneous system. Hydrate saturation is controlled by the initial thermodynamic condition of the system, and changed by the gas fractional flow. Hydrate saturation increases with the initial distance from the hydrate phase boundary. Different gas fractional flows behind the hydrate solidification front lead to different gas saturations at the hydrate solidification front. The higher the gas saturation at the front, the less the volume available to be filled by hydrate, and hence the lower the hydrate saturation. The gas fractional flow depends on the relative permeability curves, and the forces that drive the flow. Viscous forces (the drive for flow induced from liquid pressure gradient) dominate the flow, and hydrate saturation is independent on the gas supply rates and the flow directions at high gas supply rates. Hydrate saturation can be estimated as one minus the ratio of the initial to equilibrium salinity. Gravity forces (the drive for flow induced from the gravity) dominate the flow, and hydrate saturation depends on the flow rates and the flow directions at low gas supply rates. Hydrate saturation is highest for upward flow, and lowest for downward flow. Hydrate saturation decreases with the flow rate for upward flow, and increases with the flow rate for downward flow. This analytical solution illuminates how hydrate is formed by gas (methane, CO2, ethane, propane) flowing into brine-saturated sediments at both the laboratory and geological scales (Figure 1). It provides an approach to generalize the understanding of hydrate solidification in gas-rich

  4. Reaction pathways for catalytic gas-phase oxidation of glycerol over mixed metal oxides

    Energy Technology Data Exchange (ETDEWEB)

    Suprun, W.; Glaeser, R.; Papp, H. [Leipzig Univ. (Germany). Inst. of Chemical Technology

    2011-07-01

    Glycerol as a main by-product from bio-diesel manufacture is a cheap raw material with large potential for chemical or biochemical transformations to value-added C3-chemicals. One possible way of glycerol utilization involves its catalytic oxidation to acrylic acid as an alternative to petrochemical routes. However, this catalytic conversion exhibits various problems such as harsh reaction conditions, severe catalyst coking and large amounts of undesired by-products. In this study, the reaction pathways for gas-phase conversion of glycerol over transition metal oxides (Mo, V und W) supported on TiO{sub 2} and SiO{sub 2} were investigated by two methods: (i) steady state experiments of glycerol oxidation and possible reactions intermediates, i.e., acrolein, 3-hydroxy propionaldehyde and acetaldehyde, and (ii) temperature-programmed surface reaction (TPSR) studies of glycerol conversion in the presence and in the absence of gas-phase oxygen. It is shown that the supported W-, V and Mo-oxides possess an ability to catalyze the oxidation of glycerol to acrylic acid. These investigations allowed us to gain a deeper insight into the reaction mechanism. Thus, based on the obtained results, three possible reactions pathways for the selective oxidation of glycerol to acrylic acid on the transition metal-containing catalysts are proposed. The major pathways in presence of molecular oxygen are a fast successive destructive oxidation of glycerol to CO{sub x} and the dehydration of glycerol to acrolein which is a rate-limiting step. (orig.)

  5. Evaluation of SI engine exhaust gas emissions upstream and downstream of the catalytic converter

    Energy Technology Data Exchange (ETDEWEB)

    Silva, C.M.; Costa, M.; Farias, T.L. [Mechanical Engineering Department, Instituto Superior Tecnico, Technical University of Lisbon, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal); Santos, H. [Escola Superior de Tecnologia e Gestao, Instituto Politecnico de Leiria, Leiria (Portugal)

    2006-11-15

    The conversion efficiency of a catalytic converter, mounted on a vehicle equipped with a 2.8l spark ignition engine, was evaluated under steady state operating conditions. The inlet and outlet chemical species concentration, temperature and air fuel ratio (A/F) were measured as a function of the brake mean effective pressure (BMEP) and engine speed (rpm). Oil temperature, coolant temperature, brake power and spark advance were also monitored. In parallel, a mathematical model for the catalytic converter has been developed. The main inputs of the model are the temperature, flow rate, chemical species mass flow and local A/F ratio as measured at the catalyst inlet section. The main conclusions are: (i) the exhaust gas and substrate wall temperatures at the catalyst outlet increase with BMEP and rpm; (ii) the HC conversion efficiency increases with the value of BMEP up to a maximum beyond which it decreases; (iii) the CO conversion efficiencies typically increase with BMEP; (iv) the NO{sub x} conversion efficiency remains nearly constant regardless of BMEP and rpm; (v) except for idle, the NO{sub x} conversion efficiency is typically the highest, followed in turn by the CO and HC conversion efficiencies; (vi) conversion efficiencies are lower for idle conditions, which can be a problem under traffic conditions where idle is a common situation; (vii) regardless of rpm and load, for the same flow rate the conversion efficiency is about the same; (viii) the model predictions slightly over estimate the exhaust gas temperature data at the catalyst outlet section with the observed differences decreasing with BMEP and engine speed; (ix) in general, the model predictions of the conversion efficiencies are satisfactory. (author)

  6. Trends in coal gas purification processes

    Energy Technology Data Exchange (ETDEWEB)

    Latysheva, L.A.; Emel' yanova, L.P.; Popova, N.S.; Fritsler, G.S.

    1988-01-01

    Comparatively evaluates processes for coal gas purification developed and used in the GDR, FRG, France, Italy, Japan, USA, UK and other countries. The following processes are discussed: a combined process for hydrogen sulfide and ammonia removal using the USS-FOSAM process, combined removal of hydrogen sulfide and ammonia with ammonia elimination, the Stretford process, the Holmes-Stretford process, the Takahax process, the Fumaks process, the Sulfiban process, the Dimox process, The Otto-Sulfammon and the Phosam process. The following processes of coal tar purification are characterized: absorption-desorption process, oxidation, hydrogen cyanide removal, purification of gases in the Claus process, removal of nitrogen oxides, coal gas cooling and removal of dusts, tar and naphthalene, removal of hydrogen sulfide, ammonia, hydrogen cyanide and nitrogen oxides using absorbents, regeneration processes. The most efficient and economic processes and the companies that developed these processes are characterized. 25 refs.

  7. Catalytic hydrodechlorination of chloroaromatic gas streams promoted by Pd and Ni: The role of hydrogen spillover

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, Claudia [Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY (United States); Keane, Mark A., E-mail: M.A.Keane@hw.ac.uk [Chemical Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, Scotland (United Kingdom)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Effective application of catalytic hydrodechlorination in the treatment of toxic chloroaromatic gas streams. Black-Right-Pointing-Pointer Demonstration of spillover hydrogen associated with Pd/Al{sub 2}O{sub 3}, Ni/Al{sub 2}O{sub 3}, Pd + Al{sub 2}O{sub 3} and Ni + Al{sub 2}O{sub 3}. Black-Right-Pointing-Pointer Combination of Al{sub 2}O{sub 3} with Pd, Ni, Pd/Al{sub 2}O{sub 3} and Ni/Al{sub 2}O{sub 3} enhances spillover content. Black-Right-Pointing-Pointer Spillover hydrogen contributes to enhanced hydrodechlorination performance. - Abstract: Catalytic hydrodechlorination (HDC) is an effective means of detoxifying chlorinated waste. Involvement of spillover hydrogen is examined in gas phase dechlorination of chlorobenzene (CB) and 1,3-dichlorobenzene (1,3-DCB) over Pd and Ni. The catalytic action of single component Pd and Ni, Pd/Al{sub 2}O{sub 3}, Ni/Al{sub 2}O{sub 3} and physical mixtures with Al{sub 2}O{sub 3} has been considered. Catalyst activation is characterized in terms of temperature programmed reduction, the supported nano-scale metal phase by transmission electron microscopy and hydrogen/surface interactions by chemisorption/temperature programmed desorption. Pd/Al{sub 2}O{sub 3} generated significantly greater amounts of spillover hydrogen (by a factor of over 40) compared with Ni/Al{sub 2}O{sub 3}. Hydrogen spillover on Pd/Al{sub 2}O{sub 3} far exceeded the chemisorbed component, whereas chemisorbed and spillover content was equivalent for Ni/Al{sub 2}O{sub 3}. Inclusion of Al{sub 2}O{sub 3} with Ni and Ni/Al{sub 2}O{sub 3} increased spillover with an associated increase in specific HDC rate (up to a factor of 10) and enhanced selectivity to benzene from 1,3-DCB. HDC rate delivered by Pd and Pd/Al{sub 2}O{sub 3} was largely unaffected by the addition of Al{sub 2}O{sub 3}. This can be attributed to the higher intrinsic HDC performance of Pd that results in appreciable HDC activity under conditions where Ni

  8. Effect of organic matter properties, clay mineral type and thermal maturity on gas adsorption in organic-rich shale systems

    Science.gov (United States)

    Zhang, Tongwei; Ellis, Geoffrey S.; Ruppel, Stephen C.; Milliken, Kitty; Lewan, Mike; Sun, Xun

    2013-01-01

    A series of CH4 adsorption experiments on natural organic-rich shales, isolated kerogen, clay-rich rocks, and artificially matured Woodford Shale samples were conducted under dry conditions. Our results indicate that physisorption is a dominant process for CH4 sorption, both on organic-rich shales and clay minerals. The Brunauer–Emmett–Teller (BET) surface area of the investigated samples is linearly correlated with the CH4 sorption capacity in both organic-rich shales and clay-rich rocks. The presence of organic matter is a primary control on gas adsorption in shale-gas systems, and the gas-sorption capacity is determined by total organic carbon (TOC) content, organic-matter type, and thermal maturity. A large number of nanopores, in the 2–50 nm size range, were created during organic-matter thermal decomposition, and they significantly contributed to the surface area. Consequently, methane-sorption capacity increases with increasing thermal maturity due to the presence of nanopores produced during organic-matter decomposition. Furthermore, CH4 sorption on clay minerals is mainly controlled by the type of clay mineral present. In terms of relative CH4 sorption capacity: montmorillonite ≫ illite – smectite mixed layer > kaolinite > chlorite > illite. The effect of rock properties (organic matter content, type, maturity, and clay minerals) on CH4 adsorption can be quantified with the heat of adsorption and the standard entropy, which are determined from adsorption isotherms at different temperatures. For clay-mineral rich rocks, the heat of adsorption (q) ranges from 9.4 to 16.6 kJ/mol. These values are considerably smaller than those for CH4 adsorption on kerogen (21.9–28 kJ/mol) and organic-rich shales (15.1–18.4 kJ/mol). The standard entropy (Δs°) ranges from -64.8 to -79.5 J/mol/K for clay minerals, -68.1 to -111.3 J/mol/K for kerogen, and -76.0 to -84.6 J/mol/K for organic-rich shales. The affinity of CH4 molecules for sorption on organic matter

  9. Gas-rich and gas-poor structures through the stream velocity effect

    Science.gov (United States)

    Popa, Cristina; Naoz, Smadar; Marinacci, Federico; Vogelsberger, Mark

    2016-08-01

    Using adiabatic high-resolution numerical simulations, we quantify the effect of the streaming motion of baryons with respect to dark matter at the time of recombination on structure formation and evolution. Formally a second-order effect, the baryonic stream velocity has proven to have significant impact on dark matter halo abundance, as well as on the gas content and morphology of small galaxy clusters. In this work, we study the impact of stream velocity on the formation and gas content of haloes with masses up to 109 M⊙, an order of magnitude larger than previous studies. We find that the non-zero stream velocity has a sizable impact on the number density of haloes with masses ≲ few × 107 M⊙ up to z = 10, the final redshift of our simulations. Furthermore, the gas stream velocity induces a suppression of the gas fraction in haloes, which at z = 10 is ˜10 per cent for objects with M ˜ 107 M⊙, as well as a flattening of the gas density profiles in the inner regions of haloes. We further identify and study the formation, in the context of a non-zero stream velocity, of moderately long lived gas-dominated structures at intermediate redshifts 10 < z < 20, which Naoz and Narayan have recently proposed as potential progenitors of globular clusters.

  10. Radiation-catalytic processes on the surface of stainless steel+C6H14 system

    International Nuclear Information System (INIS)

    The laws of radiation-catalytic processes observed in the stainless steel and hydrocarbon contact at a liquid-phase hexane radiolysis were studied. It was established that the oxide film (basically α-Fe2O3) is formed on the surface of stainless steel depending on the preliminary radiation-oxidation treatment time. (authors)

  11. 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.

  12. Gas-Rich Mergers in LCDM: Disk Survivability and the Baryonic Assembly of Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Kyle R.; Bullock, James S.; /UC, Irvine; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC; Maller, Ariyeh H.; /New York City Coll. Tech.

    2009-08-03

    We use N-body simulations and observationally-normalized relations between dark matter halo mass, stellar mass, and cold gas mass to derive robust expectations about the baryonic content of major mergers out to redshift z {approx} 2. First, we find that the majority of major mergers (m/M > 0.3) experienced by Milky Way size dark matter halos should have been gas-rich, and that gas-rich mergers are increasingly common at high redshift. Though the frequency of major mergers into galaxy halos in our simulations greatly exceeds the observed late-type galaxy fraction, the frequency of gas-poor major mergers is consistent with the observed fraction of bulge-dominated galaxies across the halo mass range M{sub DM} {approx} 10{sup 11} - 10{sup 13} M{sub {circle_dot}}. These results lend support to the conjecture that mergers with high baryonic gas fractions play an important role in building and/or preserving disk galaxies in the universe. Secondly, we find that there is a transition mass below which a galaxy's past major mergers were primarily gas-rich and above which they were gas poor. The associated stellar mass scale corresponds closely to that marking the observed bimodal division between blue, star-forming, disk-dominated systems and red, bulge-dominated systems with old populations. Finally, we find that the overall fraction of a galaxy's cold baryons deposited directly via major mergers is substantial. Approximately 30% of the cold baryonic material in M{sub star} {approx} 10{sup 10} M{sub {circle_dot}} (M{sub DM} {approx} 10{sup 11.5} M{sub {circle_dot}}) galaxies is accreted as cold gas in major mergers. For more massive galaxies with M{sub star} {approx} 10{sup 11} M{sub {circle_dot}} (M{sub DM} {approx} 10{sup 13} M{sub {circle_dot}} the fraction of baryons amassed in mergers is even higher, {approx} 50%, but most of these accreted baryons are delivered directly in the form of stars. This baryonic mass deposition is almost unavoidable, and provides a

  13. Final Report, "Molecular Design of Hydrocarbon Oxidation Catalytic Processes"

    Energy Technology Data Exchange (ETDEWEB)

    Professor Francisco Zaera

    2007-08-09

    production of small amounts of ethylene and water, most likely via the concerted decomposition or disproportionation of the adsorbed molecular species. The bulk of the 2-iodoethanol decomposes at about 150 K via an initial carbon-iodine scission to form –O(H)CH2CH2– (~80%) and 2-hydroxyethyl (~20%) intermediates. Two competing reactions are involved with the subsequent conversion of the 2-hydroxyethyl species around 160 K, a reductive elimination with surface hydrogen to yield ethanol, and a β-H elimination to surface vinyl alcohol. The –O(H)CH2CH2–, on the other hand, dehydrogenates to a –OCH2CH2– oxametallacycle species about the same temperature. Both 2-hydroxyethyl and oxametallacycle species tautomerize to acetaldehyde, around 210 K and above 250 K, respectively, and some of that acetaldehyde desorbs while the rest decomposes to hydrogen and carbon monoxide. We contend that a better understanding of the surface chemistry of oxygen-containing surfaces can lead to better selectivities in catalysis. This is arguably the most important issue in the field of catalysis in the near future, and one that impacts several technologies of interest to DOE such as the manufacturing of speciality chemicals and the control and removal of pollutants. Additional work was performed on the characterization of the chemistry of methyl and methylene adsorbed species on oxygen-treated nickel surfaces. Complex chemistry was observed involving not only hydrogenation and dehydrogenation steps, but also C-C couplings and methylene insertions to produce heavier hydrocarbons, and oxygen insertion reactions that yield oxygenates. Finally, a dual titration technique employing xenon and a chemically sensitive probe was developed to identify minority catalytic sites on oxide surfaces. In the case of oxygen-treated Ni(110) single crystals, it was found that both hydrogen transfer with adsorbed water or ammonia and certain hydrocarbon hydrogenation reactions take place at the end of the

  14. A PROCESS FOR THE CATALYTIC OXIDATION OF HYDROCARBONS

    DEFF Research Database (Denmark)

    1999-01-01

    A process for producing an alcohol from a gaseous hydrocarbon, e.g. a lower alkane such as methane, via oxidative reaction of the hydrocarbon in a concentrated sulfuric acid medium in the presence of a catalyst employs an added catalyst comprising a substance selected from iodine, iodine compounds...

  15. VOLATILE-RICH CIRCUMSTELLAR GAS IN THE UNUSUAL 49 CETI DEBRIS DISK

    International Nuclear Information System (INIS)

    We present Hubble Space Telescope Space Telescope Imaging Spectrograph far-UV spectra of the edge-on disk around 49 Ceti, one of the very few debris disks showing submillimeter CO emission. Many atomic absorption lines are present in the spectra, most of which arise from circumstellar gas lying along the line-of-sight to the central star. We determined the line-of-sight C I column density, estimated the total carbon column density, and set limits on the O I column density. Surprisingly, no line-of-sight CO absorption was seen. We discuss possible explanations for this non-detection, and present preliminary estimates of the carbon abundances in the line-of-sight gas. The C/Fe ratio is much greater than the solar value, suggesting that 49 Cet harbors a volatile-rich gas disk similar to that of β Pictoris

  16. VOLATILE-RICH CIRCUMSTELLAR GAS IN THE UNUSUAL 49 CETI DEBRIS DISK

    Energy Technology Data Exchange (ETDEWEB)

    Roberge, Aki; Grady, Carol A. [Exoplanets and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Welsh, Barry Y. [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); Kamp, Inga [Kapteyn Astronomical Institute, University of Groningen, 9700 AV Groningen (Netherlands); Weinberger, Alycia J., E-mail: Aki.Roberge@nasa.gov [Department of Terrestrial Magnitism, Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015 (United States)

    2014-11-20

    We present Hubble Space Telescope Space Telescope Imaging Spectrograph far-UV spectra of the edge-on disk around 49 Ceti, one of the very few debris disks showing submillimeter CO emission. Many atomic absorption lines are present in the spectra, most of which arise from circumstellar gas lying along the line-of-sight to the central star. We determined the line-of-sight C I column density, estimated the total carbon column density, and set limits on the O I column density. Surprisingly, no line-of-sight CO absorption was seen. We discuss possible explanations for this non-detection, and present preliminary estimates of the carbon abundances in the line-of-sight gas. The C/Fe ratio is much greater than the solar value, suggesting that 49 Cet harbors a volatile-rich gas disk similar to that of β Pictoris.

  17. Volatile-Rich Circumstellar Gas in the Unusual 49 Ceti Debris Disk

    CERN Document Server

    Roberge, Aki; Kamp, Inga; Weinberger, Alycia J; Grady, Carol A

    2014-01-01

    We present Hubble Space Telescope STIS far-UV spectra of the edge-on disk around 49 Ceti, one of the very few debris disks showing sub-mm CO emission. Many atomic absorption lines are present in the spectra, most of which arise from circumstellar gas lying along the line-of-sight to the central star. We determined the line-of-sight CI column density, estimated the total carbon column density, and set limits on the OI column density. Surprisingly, no line-of-sight CO absorption was seen. We discuss possible explanations for this non-detection, and present preliminary estimates of the carbon abundances in the line-of-sight gas. The C/Fe ratio is much greater than the solar value, suggesting that 49 Cet harbors a volatile-rich gas disk similar to that of Beta Pictoris.

  18. Growing worldwide gas processing market improving

    International Nuclear Information System (INIS)

    International LPG markets will be relatively tight for the remainder of the 1990s. Demand growth in developing countries, particularly Asia, remains strong. In North America, despite continued strengths in natural-gas markets, Purvin ampersand Gertz inc., Dallas, believes NGL pricing will improve gradually, gas pricing will moderate, and gas-processing economics will begin recovering. The paper discusses worldwide LPG and NGL supplies and margins; supply outlook; European and Asian production; world demand; US gas supply; processing economics; US NGL supply; butane supply; increases in US NGL demand; and plant feedstocks

  19. Catalytic properties of crystalline titanium silicalites. 1. Synthesis and characterization of titanium-rich zeolites with MFI structure

    Energy Technology Data Exchange (ETDEWEB)

    Thangaraj, A.; Kumar, R.; Mirajkar, S.P.; Ratnasamy, P. (National Chemical Lab., Pune (India))

    1991-07-01

    Crystalline titanium silicalites with the MFI structure and high titanium content (Si/Ti{double bond}10) have been prepared using improved synthesis procedures. The monoclinic lattice symmetry of silicalite-1 changes to orthorhombic on introduction of titanium. The titanium silicalites retain their orthorhombic symmetry even after calcination in air. On progressive incorporation of titanium, (1) the unit cell dimensions and volume (from XRD) increase linearly, (2) the crystal size decreases progressively, (3) the intensity of the framework IR band at 960 cm{sup {minus}1} increases, (4) a band around 47,000 c{sup {minus}1} appears in the electronic spectra due to charge transfer transitions involving Ti(IV) sites, (5) the hydrophilicity of the zeolite (from water adsorptions measurements) increases, (6) the adsorption capacity for cyclohexane increases, (7) the {sup 29}Si MAS NMR lines exhibit progressive broadening, and finally (8) the catalytic activity in the hydroxylation of phenol to catechol and hydroquinone also increases markedly. Based on these observations, it is concluded that a significant fraction of titanium in these samples is situated in framework positions. The catalytic properties of these well-defined titanium-modified zeolites will be described in more detail in the subsequent parts of this series.

  20. Star formation history and evolution of gas-rich dwarf galaxies in the Centaurus A group

    CERN Document Server

    Grossi, M; Pritzl, B J; Knezek, P M; Gallagher, J S; Minchin, R F; Freeman, K C

    2006-01-01

    We analyse the properties of three unusual dwarf galaxies in the Centaurus A group discovered with the HIPASS survey. From their optical morphology they appear to be low surface brightness dwarf spheroidals, yet they are gas-rich (M_{HI}/L_{B} > 1) with gas-mass-to-stellar light ratios larger than typical dwarf irregular galaxies. Therefore these systems appear different from any dwarfs of the Local Group. They should be favoured hosts for starburst, whereas we find a faint star formation region in only one object. We have obtained 21-cm data and Hubble Space Telescope photometry in V and I bands, and have constructed Colour Magnitude Diagrams (CMDs) to investigate their stellar populations and to set a constraint on their age. From the comparison of the observed and model CMDs we infer that all three galaxies are at least older than 2 Gyr (possibly even as old as 10 Gyr) and remain gas-rich because their star formation rates (SFRs) have been very low (< 10^{-3} M_{sun}/yr) throughout. In such systems, sta...

  1. Determination of tolerances of mirror displacement and radiator gas impurity for the CBM RICH detector

    International Nuclear Information System (INIS)

    The CBM experiment at the future FAIR facility will explore nuclear matter at high net-baryon densities. One of the key observables is di-leptons as they penetrate the created matter without further strong interactions. A gaseous RICH detector in a standard projective geometry using spherical mirrors is one of two detector elements for the required electron identification. The mirror system consists of about 72 trapezoidal mirror tiles. Any misalignment between the tiles relative to the nominal common spherical surface leads to reduction of the reconstruction efficiency of Cherenkov rings and deterioration of their resolution. To determine tolerances in mirror misalignment extensive simulation and measurement studies were carried out. Pure CO2 will be used as radiator gas. Gas contamination, mainly moisture and Oxygen, reduces the number of detected photons per ring and worsens the quality of reconstructed Cherenkov rings. Therefore a study was carried out to determine tolerances in radiator gas contamination. - Highlights: • Mirror misalignment leads to ring deformation in a RICH detector. • Radiator contamination leads to resolution deterioration of fitted rings. • To determine tolerances measurements and simulations were carried out. • Mirror displacements of up to 0.32 mm at any mirror side can be tolerated. • Oxygen (moisture) contamination of up to 1% (0.0011%) can be safely tolerated

  2. Modelling of non-catalytic reactions in a gas-solid trickle flow reactor: dry, regenerative flue gas desulphurization using a silica-supported copper oxide sorbent

    OpenAIRE

    Kiel, J.H.A.; De Prins, W.; Swaaij, van, W.P.M.

    1992-01-01

    A one-dimensional, two-phase dispersed plug flow model has been developed to describe the steady-state performance of a relatively new type of reactor, the gas-solid trickle flow reactor (GSTFR). In this reactor, an upward-flowing gas phase is contacted with as downward-flowing dilute solids phase over an inert packing. The model is derived from the separate mass heat balances for both the gas and (porous) solids phases for the case of a non-catalytic gas-solid reaction, which is first-order ...

  3. COLDz: KARL G. JANSKY VERY LARGE ARRAY DISCOVERY OF A GAS-RICH GALAXY IN COSMOS

    International Nuclear Information System (INIS)

    The broad spectral bandwidth at millimeter and centimeter wavelengths provided by the recent upgrades to the Karl G. Jansky Very Large Array (VLA) has made it possible to conduct unbiased searches for molecular CO line emission at redshifts, z > 1.31. We present the discovery of a gas-rich, star-forming galaxy at z = 2.48 through the detection of CO J = 1-0 line emission in the COLDz survey and through a sensitive, Ka-band (31-39 GHz) VLA survey of a 6.5 arcmin2 region of the COSMOS field. We argue that the broad line (FWHM ∼ 570 ± 80 km s–1) is most likely to be CO J = 1-0 at z = 2.48, as the integrated emission is spatially coincident with an infrared-detected galaxy with a photometric redshift estimate of z phot = 3.2 ± 0.4. The CO J = 1-0 line luminosity is LCO′=(2.2±0.3)×1010 K km s–1 pc2, suggesting a cold molecular gas mass of M gas ∼ (2-8) × 1010 M ☉ depending on the assumed value of the molecular gas mass to CO luminosity ratio αCO. The estimated infrared luminosity from the (rest-frame) far-infrared spectral energy distribution (SED) is L IR = 2.5 × 1012 L ☉ and the star formation rate is ∼250 M ☉ yr–1, with the SED shape indicating substantial dust obscuration of the stellar light. The infrared to CO line luminosity ratio is ∼114 ± 19 L ☉/(K km s–1 pc2), similar to galaxies with similar SFRs selected at UV/optical to radio wavelengths. This discovery confirms the potential for molecular emission line surveys as a route to study populations of gas-rich galaxies in the future

  4. Numerical Simulation on the Partition of Gas-Rich Region in Overlying Strata

    Directory of Open Access Journals (Sweden)

    G. Wang

    2014-03-01

    Full Text Available In the background of Kongzhuang coal mine 7433 working face, theoretical analysis and numerical simulation are adopted. The partition method of gas-rich region in overlying strata based on the key stratum is proposed. Overlying stratas are divided into low concentration and easy for gas drainage area, high concentration and easy for drainage area, primary stress zone according to the control action of key stratum in overlying stratas. The numerical simulation shows that fissure development range is gradually scaling up ,and the development range of bed separated fissures and vertical fissures extend to the second inferior key stratum step-by-step with the working face moving forward The fissure development range stabilizes as the roof periodic motion and moves forward with the working face moving forward. Compared to traditional empirical formula calculation result, the top boundary of high concentration and easy for drainage area according to this method is higher than the calculated limit of water flowing fractured zone. The design of gas drainage can be more accurately guided. Better gas drainage effect is obtained by the design of gas drainage in 7433 working face which is based on this method and the numerical simulation result. The effectiveness and rationality of this method are verified.

  5. Properties of three gas-rich dwarfs in the Centaurus A group

    CERN Document Server

    Grossi, M; Pritzl, B J; Knezek, P M; Minchin, R F; Freeman, K C; Saha, A

    2003-01-01

    We present HST/WFPC2 observations (F555W, F814W) and ATCA high resolution HI maps of three gas-rich dwarf galaxies in the Centaurus A group discovered in two blind 21-cm surveys (HIPASS, HIDEEP). We compare their individual properties and discuss their star formation history. Although we can not constrain the age of the oldest population from the diagrams very well, the presence of an extended population of red giant stars suggests that these systems were not formed recently. The presence of asymptotic giant branch (AGB) stars in two out of three dwarfs, sets a lower limit on the age of about 6 Gyr.

  6. The denitrogenation by breathing oxygen-rich gas to prevent altitude decompression sickness

    Institute of Scientific and Technical Information of China (English)

    Hua-jun XIAO; Xiao-peng LIU; Bin ZANG; Gui-you WANG; Zhao GU

    2012-01-01

    Objective While the technology of the molecular sieve oxygen generation system(MSOGS) onboard was used,pilots could not breathe pure oxygen to eliminate nitrogen during a high altitude flight.There is no report whether it is a threat to altitude decompression sickness(ADS) or not in that condition.This experiment was intended to observe the effects of breathing different oxygen-rich gases of MSOGS on denitrogenation,so that we could make the medical physiological requirements for MSOGS on-board and provide experimental basis for aeromedical supply.Method Eight healthy males were breathed oxygenrich gases (60%,70%,80%,90%and 99.6%) in turn for 60 min,and the concentration of nitrogen,oxygen,carbon dioxide and argon at the end of expiration interval in the oxygen mask were continuously measured by a flight mass spectrometer through the oxygen mask.According to the variety of the denitrogenation rate by breathing different oxygen-rich gases,its change law was analyzed.Results There were significant differences (P<0.05) about denitrogenation rate in different oxygen-rich gases due to different oxygen concentration and breathing time.The denitrogenation rate of pure oxygen was higher than that of the others.It was indicated that the concentration of nitrogen in lung would decrease along with the increase in oxygen concentration of oxygen-rich gases,and the nitrogen concentration in the lung almost decreased by 50% or even more if people were breathed 60%~90% oxygen-rich gas longer than 60 s.Conclusion The man-made respiration environment of low nitrogen can be provided by breathing oxygen-rich gases,although the denitrogenation velocity of breathing oxygen-rich gases is lower than that of breathing pure oxygen.So it can be used as a measure to eliminate and lower the nitrogen in the body to prevent from ADS.

  7. Experimental study on catalytic steam gasification of municipal solid waste for bioenergy production in a combined fixed bed reactor

    International Nuclear Information System (INIS)

    The catalytic steam gasification of municipal solid waste (MSW) for hydrogen-rich fuel gas production was experimentally investigated in a combined fixed bed reactor using the newly developed tri-metallic catalyst. The results indicated that the supported tri-metallic catalyst had a high activity of cracking tar and hydrocarbons, upgrading the gas quality, as well as yielding a high hydrogen production in catalytic steam gasification of municipal solid waste. A series of experiments have been performed to explore the effects of catalyst presence, catalyst to MSW mass ratio (C/M), catalytic temperature, steam to MSW ratio (S/M) and MSW particle size on the composition and yield of gasification gases. The experiments demonstrated that temperature was the most important factor in this process; higher temperature contributed to more hydrogen production and gas yield. Varying catalyst to MSW mass ratio (C/M) demonstrated complex effects on gas yield and composition of MSW gasification and an optimal value of 0.5 was found in the present study. Comparing with MSW catalytic gasification, the introduction of steam improved gas quality and yield, the optimal value of S/M was found to be 1.33 under the present operating condition. It was also shown that a smaller particle size was more favorable for gas quality and yield. -- Highlights: ► The catalytic steam gasification of MSW was experimentally investigated in a fixed bed reactor. ► The effects of operating conditions on gas yield and composition of MSW gasification were explored. ► The NiLaFe/γ-Al2O3 catalyst had a high activity of cracking tar and upgrading the gas quality. ► The optimal operating parameters for catalytic steam gasification of MSW were found in this paper.

  8. Gas Phase Selective Catalytic Oxidation of Toluene to Benzaldehyde on V2O5-Ag2O/η-Al2O3 Catalyst

    Institute of Scientific and Technical Information of China (English)

    Tonglai Zhang; Liqiu Mao; Weihua Liu

    2004-01-01

    Gas phase selective catalytic oxidation of toluene to benzaldehyde was studied on V2O5-Ag2O/η-Al2O3 catalyst prepared by impregnation. The catalyst was characterized by XRD, XPS, TEM,and FT-IR. The catalytic results showed that toluene conversion and selectivity for benzaldehyde on catalyst sample No.4 (V/(V+Ag)=0.68) was higher than other catalysts with different V/Ag ratios. This was attributed to the higher surface area, larger pore volume and pore diameter of the catalyst sample No.4 than the other catalysts. The XRD patterns recorded from the catalyst before and after the oxidation reaction revealed that the new phases were developed, and this suggested that silver had entered the vanadium lattice. XPS results showed that the vanadium on the surface of No.4 and No.5 sample was more than that in the bulk, thus forming a vanadium rich layer on the surface. It was noted that when the catalyst was doped by potassium promoter, the toluene conversion and selectivity for benzaldehyde were higher than those on the undoped catalyst. This was attributed to the disordered structure of V2O5 lattice of the K-doped catalyst and a better interfacial contact between the particles.

  9. Effect of Metal Contamination on the Performance of Catalyst for Deep Catalytic Cracking Process

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhigang

    2009-01-01

    The effect of different metal contamination levels of catalysts for Deep Catalytic Cracking (DCC) on the distribu-tion and selectivity of DCC products was investigated in a FCC pilot unit. The pilot test results showed that the effects of the metal contamination level of catalyst on the propylene yield, the coke yield, the LPG yield, the gasoline yield, the selectivity of low carbon olefins, and coke selectivity was significant, and that the influence of metal contamination level on the conversion and dry gas yield was minor.

  10. Methanation process utilizing split cold gas recycle

    Science.gov (United States)

    Tajbl, Daniel G.; Lee, Bernard S.; Schora, Jr., Frank C.; Lam, Henry W.

    1976-07-06

    In the methanation of feed gas comprising carbon monoxide and hydrogen in multiple stages, the feed gas, cold recycle gas and hot product gas is mixed in such proportions that the mixture is at a temperature sufficiently high to avoid carbonyl formation and to initiate the reaction and, so that upon complete reaction of the carbon monoxide and hydrogen, an excessive adiabatic temperature will not be reached. Catalyst damage by high or low temperatures is thereby avoided with a process that utilizes extraordinarily low recycle ratios and a minimum of investment in operating costs.

  11. Space-weathering processes and products on volatile-rich asteroids

    Science.gov (United States)

    Britt, D.; Schelling, P.; Consolmagno, G.; Bradley, T.

    2014-07-01

    recombine with available solar-wind-implanted hydrogen to form trace amounts of water and OH. Mineral decomposition can be thought of as the first stage of space weathering. It produces weathered surfaces somewhat depleted in volatile elements, creates a predictable set of minor or trace minerals, and leaves the surfaces with catalytic species, primarily npFe0. However, a second stage of further reactions and weathering depends upon the presence of ''feed-stock'' components that can participate in catalyzed chemical reactions on exposed surfaces. For volatile-rich small bodies, the available materials are not only silicates, but a volatile feedstock that can include water, carbon monoxide, ammonia, to name a few. Thermodynamically-driven decomposition of silicates will produce trace amounts of npFe0 which are ideal sites for Fischer-Tropsch type (FTT) catalytic reactions that can produce organics in situ on the asteroids including alkanes, polyaromatic hydrocarbons, and amino acids (J.E. Elsila, 2012, MAPS 47). The mix and range of products depends on the composition and morphology of the mineral surface, energy inputs produced by the micrometeorite impacts or other processes, and the composition of the input volatile feedstock. FFT reactions generate long-chain carbon compounds and amino acids. Secondary reactions that generate more complex carbon compounds and amino acids are likely to occur as the organic material matures. Weathering maturity can be thought of as a function of the abundance and diversity of the weathering products. Since the npFe0 is not destroyed in the reaction, continued micrometeorite bombardment would result in continuing processing and recombination of the existing organic feedstock. More weathering would result in progressively longer-chain carbon compounds as well as more complex and diverse amino acids, and eventually the kerogen-like insoluble-organic matter that forms a large fraction of carbonaceous meteorites. This insight has several major

  12. A comparative study of gas-gas miscibility processes in underground gas storage reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Rafiee, M.M.; Schmitz, S. [DBI - Gastechnologisches Institut gGmbH, Freiberg (Germany)

    2013-08-01

    Intermixture of gases in underground gas reservoirs have had great weight for natural gas storage in UGS projects with substitution of cushion gas by inert gases or changing the stored gas quality or origin, as for the replacement of town gas by natural gas. It was also investigated during the last years for Enhanced Gas Recovery (EGR) and Carbon Capture and Storage (CCS) projects. The actual importance of its mechanisms is discussed for the H{sub 2} storage in Power to Gas to Power projects (PGP). In these approaches miscibility of the injected gas with the gas in place in the reservoir plays an important role in the displacement process. The conditions and parameters for the gas-gas displacement and mixing have been investigated in previous projects, as e.g. the miscibility of CO{sub 2} with natural gas (CLEAN). Furthermore the miscibility process of town gas with natural gas and sauer gas with sweet gas were also previously measured and compared in laboratory. The objective of this work is to investigate the miscibility of H{sub 2} injection into natural gas reservoirs using a compositional and a black oil reservoir simulator. Three processes of convection, dispersion and diffusion are considered precisely. The effect of gas miscibility is studied for both simulators and the results are compared to find optimum miscibility parameters. The findings of this work could be helpful for further pilot and field case studies to predict and monitor the changes in gas composition and quality. In future this monitoring might become more important when PGP together with H{sub 2}-UGS, as storage technology, will help to successfully implement the change to an energy supply from more renewable sources. Similarly the method confirms the use of the black oil simulator as an alternative for gas-gas displacement and sequestration reservoir simulation in comparison to the compositional simulator. (orig.)

  13. SLOWLY ROTATING GAS-RICH GALAXIES IN MODIFIED NEWTONIAN DYNAMICS (MOND)

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Salcedo, F. J.; Martinez-Garcia, E. E. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico City (Mexico); Hidalgo-Gamez, A. M., E-mail: jsanchez@astro.unam.mx [Departamento de Fisica, Escuela Superior de Fisica y Matematicas, IPN, U.P. Adolfo Lopez Mateos, C.P. 07738, Mexico City (Mexico)

    2013-03-15

    We have carried out a search for gas-rich dwarf galaxies that have lower rotation velocities in their outskirts than MOdified Newtonian Dynamics (MOND) predicts, so that the amplitude of their rotation curves cannot be fitted by arbitrarily increasing the mass-to-light ratio of the stellar component or by assuming additional undetected matter. With presently available data, the gas-rich galaxies UGC 4173, Holmberg II, ESO 245-G05, NGC 4861, and ESO 364-G029 deviate most from MOND predictions and, thereby, provide a sample of promising targets in testing the MOND framework. In the case of Holmberg II and NGC 4861, we find that their rotation curves are probably inconsistent with MOND, unless their inclinations and distances differ significantly from the nominal ones. The galaxy ESO 364-G029 is a promising target because its baryonic mass and rotation curve are similar to Holmberg II but presents a higher inclination. Deeper photometric and H I observations of ESO 364-G029, together with further decreasing systematic uncertainties, may provide a strong test to MOND.

  14. SLOWLY ROTATING GAS-RICH GALAXIES IN MODIFIED NEWTONIAN DYNAMICS (MOND)

    International Nuclear Information System (INIS)

    We have carried out a search for gas-rich dwarf galaxies that have lower rotation velocities in their outskirts than MOdified Newtonian Dynamics (MOND) predicts, so that the amplitude of their rotation curves cannot be fitted by arbitrarily increasing the mass-to-light ratio of the stellar component or by assuming additional undetected matter. With presently available data, the gas-rich galaxies UGC 4173, Holmberg II, ESO 245-G05, NGC 4861, and ESO 364-G029 deviate most from MOND predictions and, thereby, provide a sample of promising targets in testing the MOND framework. In the case of Holmberg II and NGC 4861, we find that their rotation curves are probably inconsistent with MOND, unless their inclinations and distances differ significantly from the nominal ones. The galaxy ESO 364-G029 is a promising target because its baryonic mass and rotation curve are similar to Holmberg II but presents a higher inclination. Deeper photometric and H I observations of ESO 364-G029, together with further decreasing systematic uncertainties, may provide a strong test to MOND.

  15. Slowly rotating gas-rich galaxies in modified Newtonian dynamics (MOND)

    CERN Document Server

    Sanchez-Salcedo, F J; Martinez-Garcia, Eric E

    2013-01-01

    We have carried out a search for gas-rich dwarf galaxies that have lower rotation velocities in their outskirts than MOdified Newtonian Dynamics (MOND) predicts, so that the amplitude of their rotation curves cannot be fitted by arbitrarily increasing the mass-to-light ratio of the stellar component or by assuming additional undetected matter. With presently available data, the gas-rich galaxies UGC 4173, Holmberg II, ESO 245-G05, NGC 4861 and ESO 364-G029 deviate most from MOND predictions and, thereby, provide a sample of promising targets in testing the MOND framework. In the case of Holmberg II and NGC 4861, we find that their rotation curves are probably inconsistent with MOND, unless their inclinations and distances differ significantly from the nominal ones. The galaxy ESO 364-G029 is a promising target because its baryonic mass and rotation curve are similar to Holmberg II but presents a higher inclination. Deeper photometric and HI observations of ESO 364-G029, together with further decreasing system...

  16. COLDz: Karl G. Jansky Very Large Array discovery of a gas-rich galaxy in COSMOS

    CERN Document Server

    Lentati, L; Carilli, C L; Riechers, D; Capak, P; Walter, F; Aravena, M; da Cunha, E; Hodge, J A; Ivison, R J; Smail, I; Sharon, C; Daddi, E; Decarli, R; Dickinson, M; Sargent, M; Scoville, N; Smolcic, V

    2014-01-01

    The broad spectral bandwidth at mm and cm-wavelengths provided by the recent upgrades to the Karl G. Jansky Very Large Array (VLA) has made it possible to conduct unbiased searches for molecular CO line emission at redshifts, z > 1.31. We present the discovery of a gas-rich, star-forming galaxy at z = 2.48, through the detection of CO(1-0) line emission in the COLDz survey, through a sensitive, Ka-band (31 to 39 GHz) VLA survey of a 6.5 square arcminute region of the COSMOS field. We argue that the broad line (FWHM ~570 +/- 80 km/s) is most likely to be CO(1-0) at z=2.48, as the integrated emission is spatially coincident with an infrared-detected galaxy with a photometric redshift estimate of z = 3.2 +/- 0.4. The CO(1-0) line luminosity is L'_CO = (2.2 +/- 0.3) x 10^{10} K km/s pc^2, suggesting a cold molecular gas mass of M_gas ~ (2 - 8)x10^{10}M_solar depending on the assumed value of the molecular gas mass to CO luminosity ratio alpha_CO. The estimated infrared luminosity from the (rest-frame) far-infrare...

  17. Hydrogen production from simulated hot coke oven gas by catalytic reforming over Ni/Mg(A1)O catalysts

    Institute of Scientific and Technical Information of China (English)

    Hongwei Cheng; Baohua Yue; Xueguang Wang; Xionggang Lu; Weizhong Ding

    2009-01-01

    Hydrogen production by catalytic reforming of simulated hot coke oven gas (HCOG) with toluene as a model tar compound was investigated in a fixed bed reactor over Ni/Mg(Al)O catalysts. The catalysts were prepared by a homogeneous precipitation method using urea hydrolysis and characterized by ICP,BET, XRD, TPR, TEM and TG. XRD showed that the hydrotalcite type precursor after calcination formed (Ni,Mg)Al2O4 spinel and Ni-Mg-O solid solution structure. TPR results suggested that the increase in Ni/Mg molar ratio gave rise to the decrease in the reduction temperature of Ni2+ to Ni0 on Ni/Mg(Al)O catalysts. The reaction results indicated that toluene and CH4 could completely be converted to H2 and CO in the catalytic reforming of the simulated HCOG under atmospheric pressure and the amount of H2 in the reaction effluent gas was about 4 times more than that in original HCOG. The catalysts with lower Ni/Mg molar ratio showed better catalytic activity and resistance to ceking, which may become promising catalysts in the catalytic reforming of HCOG.

  18. Component Development to Accelerate Commercial Implementation of Ultra-Low Emissions Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    McCarty, Jon; Berry, Brian; Lundberg, Kare; Anson, Orris

    2003-03-31

    This final report describes a 2000-2003 program for the development of components and processes to enhance the commercialization of ultra-low emissions catalytic combustion in industrial gas turbines. The range of project tasks includes: development of more durable, lower-cost catalysts and catalytic combustor components; development and design of a catalytic pre-burner and a catalytic pilot burner for gas turbines, and on-site fuel conversion processing for utilization of liquid fuel.

  19. New catalytic processes for the recycling of lignocellulosic waste, polymers and CO₂ derivatives

    OpenAIRE

    Feghali, Elias

    2015-01-01

    The objective of this thesis was the development of new innovative synthetic methods for recycling waste carbon compounds or renewable raw materials to improve the sustainability of the industrial chemical sector and reduce its dependence on fossil resources. In this context, the work has been performed following three main areas of research intended for the development of new catalytic processes for the valorization of oxalic acid, derived from CO2, waste polymer materials and biomass. To ac...

  20. Geopolymers based on spent catalyst residue from a fluid catalytic cracking (FCC) process

    OpenAIRE

    RODRIGUEZ MARTINEZ, ERICH DAVID; Bernal, Susan A.; Provis, John L.; Gehman, John D.; Monzó Balbuena, José Mª; Paya Bernabeu, Jorge Juan; Borrachero Rosado, María Victoria

    2013-01-01

    This paper assesses the use of alkali activation technology in the valorization of a spent fluid catalytic cracking (FCC) catalyst, which is a residue derived from the oil-cracking process, to produce geopolymer binders. In particular, the effects of activation conditions on the structural characteristics of the spent catalyst- based geopolymers are determined. The zeolitic phases present in the spent catalyst are the main phases participating in the geopolymerization reaction, which is ...

  1. Characterization and catalytic performance of CeO2-Co/SiO2 catalyst for Fischer-Tropsch synthesis using nitrogen-diluted synthesis gas over a laboratory scale fixed-bed reactor

    Institute of Scientific and Technical Information of China (English)

    Xiaoping Dai; Changchun Yu

    2008-01-01

    The surface species of CO hydrogenation on CeO2-Co/SiO2 catalyst were investigated using the techniques of temperature programmed reaction and transient response method. The results indicated that the formation of H2O and CO2 was the competitive reaction for the surface oxygen species, CH4 was produced via the hydrogenation of carbon species step by step, and C2 products were formed by the polymerization of surface-active carbon species (-CH2-). Hydrogen assisted the dissociation of CO. The hydrogenation of surface carbon species was the rate-limiting step in the hydrogenation of CO over CeO2-Co/SiO2 catalyst. The investigation of total pressure, gas hourly space velocity (GHSV), and product distribution using nitrogen-rich synthesis gas as feedstock over a laboratory scale fixed-bed reactor indicated that total pressure and GHSV had a significant effect on the catalytic performance of CeO2-Co/SiO2 catalyst. The removal of heat and control of the reaction temperature were extremely critical steps, which required lower GHSV and appropriate CO conversion to avoid the deactivation of the catalyst. The feedstock of nitrogen-rich synthesis gas was favorable to increase the conversion of CO, but there was a shift of product distribution toward the light hydrocarbon. The nitrogen-rich synthesis gas was feasible for F-T synthesis for the utilization of remote natural gas.

  2. Rate processes in gas phase

    International Nuclear Information System (INIS)

    Reaction-rate theory and experiment are given a critical review from the engineers' point of view. Rates of heavy-particle, collision-induced reaction in gas phase are formulated in terms of the cross sections and activation energies of the reaction. The effect of cross section function shape and of excited state contributions to the reaction both cause the slope of Arrhenius plots to differ from the true activation energy, except at low temperature. The master equations for chemically reacting gases are introduced, and dissociation and ionization reactions are shown to proceed primarily from excited states about kT from the dissociation or ionization limit. Collision-induced vibration, vibration-rotation, and pure rotation transitions are treated, including three-dimensional effects and conservation of energy, which have usually been ignored. The quantum theory of transitions at potential surface crossing is derived, and results are found to be in fair agreement with experiment in spite of some questionable approximations involved

  3. Design of Apparatus for Testing of Catalytic Filters for Flue Gas Treatment

    Czech Academy of Sciences Publication Activity Database

    Zach, Boleslav

    Prague : Institute of Chemical Process Fundamental of the CAS, v. v. i, 2015 - (Bendová, M.; Wagner, Z.), s. 26-27 ISBN 978-80-86186-70-2. [Bažant Postgraduate Conference 2015. Prague (CZ)] Institutional support: RVO:67985858 Keywords : flue gas * cleaning sytem * testing Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  4. Exoemission and catalytic activity of oxides of the perovskite and spinel structures in the processes of CO and hydrocarbons oxidation

    International Nuclear Information System (INIS)

    Low-temperature (20-400 deg C) exoemission of negative charges from complex oxides featuring perovskite structure AMO3 (A = La; M = Co, Mn, Ni) and spinel structure A'M'2O4 (A' = Cu; M' = Fe, Co, Cr) was studied using the Geiger gas-flow counter. The experiments were carried out under conditions of thermally induced emission, photo- and thermally induced emission during irradiation of samples by UV light with the wavelength of 313 nm, as well as thermally induced emission under effect of β-radiation of 90Y-90Sr with dose of 0.23 Gy. Correlation between emissivity of the oxides and catalytic activity was established. The role of weakly bound oxygen and variable valency ions in exoemission and oxidizing catalysis processes involving the complex oxides was discussed

  5. A novel miRNA processing pathway independent of Dicer requires Argonaute2 catalytic activity.

    Science.gov (United States)

    Cifuentes, Daniel; Xue, Huiling; Taylor, David W; Patnode, Heather; Mishima, Yuichiro; Cheloufi, Sihem; Ma, Enbo; Mane, Shrikant; Hannon, Gregory J; Lawson, Nathan D; Wolfe, Scot A; Giraldez, Antonio J

    2010-06-25

    Dicer is a central enzyme in microRNA (miRNA) processing. We identified a Dicer-independent miRNA biogenesis pathway that uses Argonaute2 (Ago2) slicer catalytic activity. In contrast to other miRNAs, miR-451 levels were refractory to dicer loss of function but were reduced in MZago2 (maternal-zygotic) mutants. We found that pre-miR-451 processing requires Ago2 catalytic activity in vivo. MZago2 mutants showed delayed erythropoiesis that could be rescued by wild-type Ago2 or miR-451-duplex but not by catalytically dead Ago2. Changing the secondary structure of Dicer-dependent miRNAs to mimic that of pre-miR-451 restored miRNA function and rescued developmental defects in MZdicer mutants, indicating that the pre-miRNA secondary structure determines the processing pathway in vivo. We propose that Ago2-mediated cleavage of pre-miRNAs, followed by uridylation and trimming, generates functional miRNAs independently of Dicer. PMID:20448148

  6. Catalytic pyrolysis of biomass: Effects of pyrolysis temperature, sweeping gas flow rate and MgO catalyst

    International Nuclear Information System (INIS)

    Cotton seed, as a biomass source, is pyrolysed in a tubular fixed-bed reactor under various sweeping gas (N2) flow rates at different pyrolysis temperatures. In the non-catalytic work, the maximum bio-oil yield was attained as 48.30% at 550 oC with a sweeping gas flow rate of 200 mL min-1. At the optimum conditions, catalytic pyrolysis of biomass samples was performed with various amounts of MgO catalyst (5, 10, 15, and 20 wt.% of raw material). Catalyst addition decreased the quantity of bio-oil yet increased the quality of bio-oil in terms of calorific value, hydrocarbon distribution and removal of oxygenated groups. It was observed that increasing the amount of catalyst used, decreased the oil yields while increased the gas and char yields. Bio-oils obtained at the optimum conditions were separated into aliphatic, aromatic and polar sub-fractions. After the application of column chromatography, bio-oils were subjected into elemental, FT-IR and 1H NMR analyses. Aliphatic sub-fractions of bio-oils were analyzed by GC-MS. It was deduced that the fuel obtained via catalytic pyrolysis mainly consisted of lower weight hydrocarbons in the diesel range. Finally, obtained results were compared with petroleum fractions and evaluated as a potential source for liquid fuels.

  7. Massive black hole binaries in gas-rich galaxy mergers; multiple regimes of orbital decay and interplay with gas inflows

    Science.gov (United States)

    Mayer, Lucio

    2013-12-01

    gas inflows in gas-rich galaxies undergoing major mergers. We derive a condition for the maximum inflow rate that a circumnuclear disc can host while still maintaining a sufficiently high gas density at large radii to sustain the decay of a BH binary. We find that gas inflows rates exceeding 10 M⊙ yr-1, postulated to form massive BH seeds in some direct collapse models, would stifle the sinking of massive BH binaries in gas-dominated galactic nuclei. Vice-versa, lower inflow rates, below a solar mass per year, as required to feed typical active galactic nuclei (AGNs), are compatible with a fast orbital decay of BH binaries across a wide range of masses.

  8. COLDz: KARL G. JANSKY VERY LARGE ARRAY DISCOVERY OF A GAS-RICH GALAXY IN COSMOS

    Energy Technology Data Exchange (ETDEWEB)

    Lentati, L. [Astrophysics Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Wagg, J. [Square Kilometre Array Organisation, Jodrell Bank Observatory, Lower Withington, Macclesfield, Cheshire SK11 9DL (United Kingdom); Carilli, C. L. [National Radio Astronomy Observatory, Socorro, NM 87801 (United States); Riechers, D.; Sharon, C. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Capak, P.; Scoville, N. [California Institute of Technology, MC 105-24, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Walter, F.; Da Cunha, E.; Decarli, R. [Max-Planck Institute for Astronomy, D-69117 Heidelberg (Germany); Aravena, M. [Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago (Chile); Hodge, J. A. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Ivison, R. J. [European Southern Observatory, Karl-Schwarzschild Strasse, D-85748 Garching bei Munchen (Germany); Smail, I. [Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham, DH1 3LE (United Kingdom); Daddi, E. [CEA-Saclay, Service d' Astrophysique, F-91191 Gif-sur-Yvette (France); Dickinson, M. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Sargent, M. [Astronomy Centre, Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH (United Kingdom); Smolčć, V., E-mail: ltl21@mrao.cam.ac.uk [University of Zagreb, Bijenicka cesta 32, HR-10002 Zagreb (Croatia)

    2015-02-10

    The broad spectral bandwidth at millimeter and centimeter wavelengths provided by the recent upgrades to the Karl G. Jansky Very Large Array (VLA) has made it possible to conduct unbiased searches for molecular CO line emission at redshifts, z > 1.31. We present the discovery of a gas-rich, star-forming galaxy at z = 2.48 through the detection of CO J = 1-0 line emission in the COLDz survey and through a sensitive, Ka-band (31-39 GHz) VLA survey of a 6.5 arcmin{sup 2} region of the COSMOS field. We argue that the broad line (FWHM ∼ 570 ± 80 km s{sup –1}) is most likely to be CO J = 1-0 at z = 2.48, as the integrated emission is spatially coincident with an infrared-detected galaxy with a photometric redshift estimate of z {sub phot} = 3.2 ± 0.4. The CO J = 1-0 line luminosity is L{sub CO}{sup ′}=(2.2±0.3)×10{sup 10} K km s{sup –1} pc{sup 2}, suggesting a cold molecular gas mass of M {sub gas} ∼ (2-8) × 10{sup 10} M {sub ☉} depending on the assumed value of the molecular gas mass to CO luminosity ratio α{sub CO}. The estimated infrared luminosity from the (rest-frame) far-infrared spectral energy distribution (SED) is L {sub IR} = 2.5 × 10{sup 12} L {sub ☉} and the star formation rate is ∼250 M {sub ☉} yr{sup –1}, with the SED shape indicating substantial dust obscuration of the stellar light. The infrared to CO line luminosity ratio is ∼114 ± 19 L {sub ☉}/(K km s{sup –1} pc{sup 2}), similar to galaxies with similar SFRs selected at UV/optical to radio wavelengths. This discovery confirms the potential for molecular emission line surveys as a route to study populations of gas-rich galaxies in the future.

  9. Formic Acid Free Flowsheet Development To Eliminate Catalytic Hydrogen Generation In The Defense Waste Processing

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, Dan P.; Stone, Michael E.; Newell, J. David; Fellinger, Terri L.; Bricker, Jonathan M.

    2012-09-14

    The Defense Waste Processing Facility (DWPF) processes legacy nuclear waste generated at the Savannah River Site (SRS) during production of plutonium and tritium demanded by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass canisters is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides. Testing was initiated to determine whether the elimination of formic acid from the DWPF's chemical processing flowsheet would eliminate catalytic hydrogen generation. Historically, hydrogen is generated in chemical processing of alkaline High Level Waste sludge in DWPF. In current processing, sludge is combined with nitric and formic acid to neutralize the waste, reduce mercury and manganese, destroy nitrite, and modify (thin) the slurry rheology. The noble metal catalyzed formic acid decomposition produces hydrogen and carbon dioxide. Elimination of formic acid by replacement with glycolic acid has the potential to eliminate the production of catalytic hydrogen. Flowsheet testing was performed to develop the nitric-glycolic acid flowsheet as an alternative to the nitric-formic flowsheet currently being processed at the DWPF. This new flowsheet has shown that mercury can be reduced and removed by steam stripping in DWPF with no catalytic hydrogen generation. All processing objectives were also met, including greatly reducing the Slurry Mix Evaporator (SME) product yield stress as compared to the baseline nitric/formic flowsheet. Ten DWPF tests were performed with nonradioactive simulants designed to cover a broad compositional range. No hydrogen was generated in testing without formic acid.

  10. Off-gas processing device

    International Nuclear Information System (INIS)

    Purpose: To remove volatile ruthenium in off-gases at high efficiency. Constitution: In a pre-processing tower, off-gases are at first washed by a scrubber thereby removing most of impurity ingredients such as NOx having strong affinity with scrubbing water to increase the relative ratio of volatile ruthenium relative to the impurity ingredients in the off-gases. Then, the off-gases are once cooled to condensate to about 20 deg C by a cooler and mist components are removed by a demister and, further, heated by a heater to 70 - 80 deg C to reduce the water concentration in the off-gases to less than about 4 %. Since most of noxious materials to silica gel such NOx or water content are eliminated by way of the adsorption tower after applying such a pre-treatment, adsorption can be conducted in the adsorption tower mainly for volatile ruthenium. (Seki, T.)

  11. Electron beam flue gas treatment process. Review

    International Nuclear Information System (INIS)

    The basis of the process for electron beam flue gas treatment are presented in the report. In tabular form the history of the research is reviewed. Main dependences of SO2 and NOx removal efficiencies on different physico-chemical parameters are discussed. Trends concerning industrial process implementation are presented in the paper,finally. (author). 74 refs, 11 figs, 1 tab

  12. [Degradation of phenol with a Fe/cu-catalytic heterogeneous-Fenton process].

    Science.gov (United States)

    Yang, Yue-Zhu; Li, Yu-Ping; Yang, Dao-Wu; Duan, Feng; Cao, Hong-Bin

    2013-07-01

    The catalysts of Fe/AC, Cu/AC and Fe-Cu/AC with active carbon as support were prepared by a wet impregnation method, and were characterized using X-ray diffraction (XRD), nitrogen adsorption and X-ray photoelectron spectroscopy (XPS) measurements; the catalytic heterogeneous-Fenton processes of phenol degradation with these catalysts were also investigated, and the degradation mechanism was discussed with analysis of intermediate products and electron spin resonance (ESR) measurement. The results showed that the active component states varied in different catalysts; CuO was the main state of Cu in Cu/AC and Fe exhibited various valence states in Fe/AC. The degradation rate of phenol with Fe/AC, Cu/AC and Fe-Cu/AC as catalyst in the initial 60 min reached 96.7%, 77.5% and 99%, respectively; the dissolution of a little active-component metal was found in Cu/AC and Fe-Cu/AC, but little Fe in Fe/AC was dissolved; the degradation of phenol was performed by heterogeneous Fe/AC instead of dissolved Fe, and the degradation rate was above 93% after Fe/AC was used for three cycle runs, showing a stable catalytic activity. Under the optimum conditions of pH = 3, T = 303 K, and 4.38 mmol x L(-1) H2O2, the removal of phenol and TOC in the Fe/AC-catalytic Fenton process could reach 97% and 53%, respectively, while little phenol was degraded without catalyst. The ESR results indicated that hydroxyl radical was produced in the catalytic decomposition of H2O2 with Fe/AC as catalyst, demonstrating that the degradation of phenol mainly followed an oxidation pathway of hydroxyl radical; intermediates such as hydroquinone, p-benzenequinone and catechol were obtained, and the results showed thatortho- and para-substitution reaction by hydroxyl might be the main mechanism of phenol oxidation. PMID:24027996

  13. New technological developments in gas processing

    International Nuclear Information System (INIS)

    The changes that the natural gas industry has undergone over the last few years was discussed. Low natural gas prices forced companies to react to their high reserves replacements costs. They were forced to downsize and undergo major restructuring because they were losing money due to high operating costs; the future for natural gas prices looked pessimistic. The changes have led to a new kind of business practice, namely 'partnering with third party processor', mid-stream companies known as aggregators, to build and operate facilities as part of a move towards cost effective improvements for gas producers. Besides reducing capital and operating costs, the producer under this arrangements can dedicate his capital to finding new gas which is the basis of growth. Recent technological changes in the gas processing industry were also touched upon. These included enhanced technologies such as increased liquid hydrocarbon recovery, segregation of C3+ and C5+, installation of gas separation membrane systems, small sulphur plants, acid gas injection and selective or mixed solvents. Details of some of these technologies were described. 2 refs., 2 figs

  14. The frequency and properties of young tidal dwarf galaxies in nearby gas-rich groups

    Science.gov (United States)

    Lee-Waddell, K.; Spekkens, K.; Chandra, P.; Patra, N.; Cuillandre, J.-C.; Wang, J.; Haynes, M. P.; Cannon, J.; Stierwalt, S.; Sick, J.; Giovanelli, R.

    2016-08-01

    We present high-resolution Giant Metrewave Radio Telescope (GMRT) H I observations and deep Canada-France-Hawaii Telescope (CFHT) optical imaging of two galaxy groups: NGC 4725/47 and NGC 3166/9. These data are part of a multi-wavelength unbiased survey of the gas-rich dwarf galaxy populations in three nearby interacting galaxy groups. The NGC 4725/47 group hosts two tidal knots and one dwarf irregular galaxy (dIrr). Both tidal knots are located within a prominent H I tidal tail, appear to have sufficient mass (Mgas ≈ 108 M⊙) to evolve into long-lived tidal dwarf galaxies (TDGs) and are fairly young in age. The NGC 3166/9 group contains a TDG candidate, AGC 208457, at least three dIrrs and four H I knots. Deep CFHT imaging confirms that the optical component of AGC 208457 is bluer - with a 0.28 mag g - r colour - and a few Gyr younger than its purported parent galaxies. Combining the results for these groups with those from the NGC 871/6/7 group reported earlier, we find that the H I properties, estimated stellar ages and baryonic content of the gas-rich dwarfs clearly distinguish tidal features from their classical counterparts. We optimistically identify four potentially long-lived tidal objects associated with three separate pairs of interacting galaxies, implying that TDGs are not readily produced during interaction events as suggested by some recent simulations. The tidal objects examined in this survey also appear to have a wider variety of properties than TDGs of similar mass formed in current simulations of interacting galaxies, which could be the result of pre- or post-formation environmental influences.

  15. IFPEXOL for environmentally sound gas processing

    International Nuclear Information System (INIS)

    Natural gas and gas associated with crude oil must be treated to remove undesirable impurities and condensable hydrocarbons in order to meet pipeline and consumer specifications. The treatment steps normally used are expensive to install and require large amounts of energy to operate, energy which could otherwise be sold to the customer. Energy efficient processes costing less to build that respect all environmental standards continue to hold top priority, and the IFPEXOL process goes far in meeting these needs. IFPEXOL integrates the classic gas treatment steps into a two-part process, IFPEX-1 and IFPEX-2 to be successively described in this paper. The same inexpensive solvent is used in both processes. Either process can be used alone if need be. IFPEX-1 is used for dew point control, dehydration, and hydrate protection while IFPEX-2 is used for acid gas removal. The first start-up and operating experience using the IFPEX-1 part of IFPEXOL process for dehydration will be discussed in this paper

  16. Expression and purification of correctly processed, active human TACE catalytic domain in Saccharomyces cerevisiae.

    Science.gov (United States)

    Clarke, H R; Wolfson, M F; Rauch, C T; Castner, B J; Huang, C P; Gerhart, M J; Johnson, R S; Cerretti, D P; Paxton, R J; Price, V L; Black, R A

    1998-06-01

    Human tumor necrosis factor-alpha (TNF alpha) converting enzyme (TACE) releases soluble TNF alpha from cells. It is a member of the adamalysin family of metalloproteases. A truncated form of TACE cDNA was expressed in Saccharomyces cerevisiae and purified to homogeneity in order to study TACE structure and function. Recombinant TACE was expressed as a preproprotein including the pro- and catalytic (PROCAT) domains fused to the yeast alpha-factor leader. A C-terminal immunoreactive FLAG peptide was added for Western blot detection and anti-FLAG antibody column purification. We constructed two glycosylation mutant PROCAT TACE isoforms to facilitate purification. A PROCAT isoform, mutated to eliminate two N-linked glycosylation sites, was buffer exchanged and purified to homogeneity by ion exchange chromatography and an anti-FLAG antibody affinity step. N-terminal sequence analysis showed that the mutant preproprotein was processed in yeast at the furin protease cleavage site and yielded an active catalytic domain which has TNF alpha peptide-specific protease activity. Mass spectrometry of the purified catalytic domain showed that removal of both N-linked sites results in a homogeneous sized polypeptide lacking further posttranslational modifications. PMID:9631522

  17. A hybrid process combining homogeneous catalytic ozonation and membrane distillation for wastewater treatment.

    Science.gov (United States)

    Zhang, Yong; Zhao, Peng; Li, Jie; Hou, Deyin; Wang, Jun; Liu, Huijuan

    2016-10-01

    A novel catalytic ozonation membrane reactor (COMR) coupling homogeneous catalytic ozonation and direct contact membrane distillation (DCMD) was developed for refractory saline organic pollutant treatment from wastewater. An ozonation process took place in the reactor to degrade organic pollutants, whilst the DCMD process was used to recover ionic catalysts and produce clean water. It was found that 98.6% total organic carbon (TOC) and almost 100% salt were removed and almost 100% metal ion catalyst was recovered. TOC in the permeate water was less than 16 mg/L after 5 h operation, which was considered satisfactory as the TOC in the potassium hydrogen phthalate (KHP) feed water was as high as 1000 mg/L. Meanwhile, the membrane distillation flux in the COMR process was 49.8% higher than that in DCMD process alone after 60 h operation. Further, scanning electron microscope images showed less amount and smaller size of contaminants on the membrane surface, which indicated the mitigation of membrane fouling. The tensile strength and FT-IR spectra tests did not reveal obvious changes for the polyvinylidene fluoride membrane after 60 h operation, which indicated the good durability. This novel COMR hybrid process exhibited promising application prospects for saline organic wastewater treatment. PMID:27372262

  18. Isotopic excesses of proton-rich nuclei related to space weathering observed in a gas-rich meteorite Kapoeta

    International Nuclear Information System (INIS)

    The idea that solar system materials were irradiated by solar cosmic rays from the early Sun has long been suggested, but is still questionable. In this study, Sr, Ba, Ce, Nd, Sm, and Gd isotopic compositions of sequential acid leachates from the Kapoeta meteorite (howardite) were determined to find systematic and correlated variations in their isotopic abundances of proton-rich nuclei, leading to an understanding of the irradiation condition by cosmic rays. Significantly large excesses of proton-rich isotopes (p-isotopes), 84Sr, 130Ba, 132Ba, 136Ce, 138Ce, and 144Sm, were observed, particularly in the first chemical separate, which possibly leached out of the very shallow layer within a few μm from the surface of regolith grains in the sample. The results reveal the production of p-isotopes through the interaction of solar cosmic rays with the superficial region of the regolith grains before the formation of the Kapoeta meteorite parent body, suggesting strong activity in the early Sun.

  19. Elimination Of Catalytic Hydrogen Generation In Defense Waste Processing Facility Slurries

    International Nuclear Information System (INIS)

    Based on lab-scale simulations of Defense Waste Processing Facility (DWPF) slurry chemistry, the addition of sodium nitrite and sodium hydroxide to waste slurries at concentrations sufficient to take the aqueous phase into the alkaline region (pH > 7) with approximately 500 mg nitrite ion/kg slurry (assuming < 25 wt% total solids, or equivalently 2,000 mg nitrite/kg total solids) is sufficient to effectively deactivate the noble metal catalysts at temperatures between room temperature and boiling. This is a potential strategy for eliminating catalytic hydrogen generation from the list of concerns for sludge carried over into the DWPF Slurry Mix Evaporator Condensate Tank (SMECT) or Recycle Collection Tank (RCT). These conclusions are drawn in large part from the various phases of the DWPF catalytic hydrogen generation program conducted between 2005 and 2009. The findings could apply to various situations, including a solids carry-over from either the Sludge Receipt and Adjustment Tank (SRAT) or Slurry Mix Evaporator (SME) into the SMECT with subsequent transfer to the RCT, as well as a spill of formic acid into the sump system and transfer into an RCT that already contains sludge solids. There are other potential mitigating factors for the SMECT and RCT, since these vessels are typically operated at temperatures close to the minimum temperatures that catalytic hydrogen has been observed to occur in either the SRAT or SME (pure slurry case), and these vessels are also likely to be considerably more dilute in both noble metals and formate ion (the two essential components to catalytic hydrogen generation) than the two primary process vessels. Rhodium certainly, and ruthenium likely, are present as metal-ligand complexes that are favored under certain concentrations of the surrounding species. Therefore, in the SMECT or RCT, where a small volume of SRAT or SME material would be significantly diluted, conditions would be less optimal for forming or sustaining the

  20. Elimination Of Catalytic Hydrogen Generation In Defense Waste Processing Facility Slurries

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D. C.

    2013-01-22

    Based on lab-scale simulations of Defense Waste Processing Facility (DWPF) slurry chemistry, the addition of sodium nitrite and sodium hydroxide to waste slurries at concentrations sufficient to take the aqueous phase into the alkaline region (pH > 7) with approximately 500 mg nitrite ion/kg slurry (assuming <25 wt% total solids, or equivalently 2,000 mg nitrite/kg total solids) is sufficient to effectively deactivate the noble metal catalysts at temperatures between room temperature and boiling. This is a potential strategy for eliminating catalytic hydrogen generation from the list of concerns for sludge carried over into the DWPF Slurry Mix Evaporator Condensate Tank (SMECT) or Recycle Collection Tank (RCT). These conclusions are drawn in large part from the various phases of the DWPF catalytic hydrogen generation program conducted between 2005 and 2009. The findings could apply to various situations, including a solids carry-over from either the Sludge Receipt and Adjustment Tank (SRAT) or Slurry Mix Evaporator (SME) into the SMECT with subsequent transfer to the RCT, as well as a spill of formic acid into the sump system and transfer into an RCT that already contains sludge solids. There are other potential mitigating factors for the SMECT and RCT, since these vessels are typically operated at temperatures close to the minimum temperatures that catalytic hydrogen has been observed to occur in either the SRAT or SME (pure slurry case), and these vessels are also likely to be considerably more dilute in both noble metals and formate ion (the two essential components to catalytic hydrogen generation) than the two primary process vessels. Rhodium certainly, and ruthenium likely, are present as metal-ligand complexes that are favored under certain concentrations of the surrounding species. Therefore, in the SMECT or RCT, where a small volume of SRAT or SME material would be significantly diluted, conditions would be less optimal for forming or sustaining the

  1. Dynamic Modeling and Simulation of a Commercial Naphtha Catalytic Reforming Process

    Institute of Scientific and Technical Information of China (English)

    胡永有; 徐巍华; 侯卫锋; 苏宏业; 褚健

    2005-01-01

    A first principles-based dynamic model for a continuous catalyst regeneration (CCR) platforming process, the UOP commercial naphtha catalytic reforming process, is developed in this paper. The lumping details of the naphtha feed and reaction scheme of the reaction model are given. The process model is composed of the reforming reaction model with catalyst deactivation, the furnace model and the separator model, which is capable of capturing the major dynamics that occurs in this process system. Dynamic simulations are performed based on Gear numerical algorithm and method of lines (MOL), a numerical technique dealing with partial differential equations (PDEs). The results of simulation are also presented. Dynamic responses caused by disturbances in the process system can be correctly predicted through simulations.

  2. The Impurity Processing Loop for the JET active gas handling plant

    International Nuclear Information System (INIS)

    The Impurity Processing Loop (IPL) of the JET Active Gas Handling System is designed to recover tritium from impurities such as tritiated water and hydrocarbons present in the JET plasma exhaust. All impurities are fully oxidized in a catalytic recombiner, the tritiated water frozen in a cold trap and subsequently decomposed on hot uranium powder. Hydrogen isotopes set free in this reaction are scavenged from the helium carrier gas in a cold uranium bed. The modular design of the IPL permits implementation of advanced processing schemes (EG avoiding solid UO2 waste) in the future without major hardware modifications

  3. The frequency and properties of young tidal dwarf galaxies in nearby gas-rich groups

    CERN Document Server

    Lee-Waddell, K; Chandra, P; Patra, N; Cuillandre, J -C; Wang, J; Haynes, M P; Cannon, J; Stierwalt, S; Sick, J; Giovanelli, R

    2016-01-01

    We present high-resolution Giant Metrewave Radio Telescope (GMRT) HI observations and deep Canada-France-Hawaii Telescope (CFHT) optical imaging of two galaxy groups: NGC 4725/47 and NGC 3166/9. These data are part of a multi-wavelength unbiased survey of the gas-rich dwarf galaxy populations in three nearby interacting galaxy groups. The NGC 4725/47 group hosts two tidal knots and one dIrr. Both tidal knots are located within a prominent HI tidal tail, appear to have sufficient mass (M_gas~10^8 M_sol) to evolve into long-lived tidal dwarf galaxies (TDGs) and are fairly young in age. The NGC 3166/9 group contains a TDG candidate, AGC 208457, at least three dIrrs and four HI knots. Deep CFHT imaging confirms that the optical component of AGC 208457 is bluer -- with a 0.28 mag g-r colour -- and a few Gyr younger than its purported parent galaxies. Combining the results for these groups with those from the NGC 871/6/7 group reported earlier, we find that the HI properties, estimated stellar ages and baryonic con...

  4. Searching for Gas-Rich Disks around T Tauri Stars in Lupus

    CERN Document Server

    van Kempen, T A; Brinch, C; Hogerheijde, M R

    2006-01-01

    AIMS : To characterize the molecular environment of classical T Tauri stars in Lupus observed with the Spitzer Space Telescope and to search for gas-rich disks toward these sources. METHODS : Submillimeter observations of 12CO, 13CO and C18O in the J=3-2 and 2-1 lines were obtained with the James Clerk Maxwell Telescope toward a sample of 21 T Tauri stars with disks in the Lupus molecular clouds. Pointings at the sources and at selected off-positions are presented in order to disentangle material associated with disks from ambient cloud material. RESULTS : One source, IM Lup (Sz 82), has been found with double-peaked 12CO and 13CO profiles characteristic of a large rotating gas disk. The inclination of the disk is found to be ~20 degrees, with an outer radius of 400-700 AU. For most other sources, including GQ Lup with its substellar companion, the single-dish 12CO lines are dominated by extended cloud emission with a complex velocity structure. No evidence for molecular outflows is found. Compact C18O emissi...

  5. Co-processing, catalytic reduction and remote controlled oxalate precipitation - a new route for 233U/Th MOX

    International Nuclear Information System (INIS)

    Reprocessing and recycling of fissile and fertile nuclides together without their individual separation is considered to be one of the few proliferation resistant approaches for closing the nuclear fuel cycle. The present paper explores the possibility of reducing the uranium to U4+ catalytically using H2 gas, co-precipitating both Th and U as oxalate and final conversion to oxide

  6. Screening process : oil and gas industry projects

    International Nuclear Information System (INIS)

    An updated version of the screening process used by Saskatchewan Environment and Resource Management (SERM) under the Environmental Assessment Act is presented. Improvements have been made to increase the effectiveness and timeliness of oil and gas project proposal reviews. Each year, SERM reviews hundreds of proposals for oil and gas projects which vary from small geophysical exploration programs to intensive production programs involving wells and related facilities. As of February 1, 1999 companies must contact the Oil and Gas Coordinator in the ecoregion where an exploration or production project is planned. This paper also describes other changes under SERM's review process including regulated pipelines, hydrostatic tests, exploration and production. There have been no changes for waste treatment and National Energy Board (NEB) projects. These will continue to be handled by the Environmental Assessment Branch in Regina. 1 fig

  7. Dynamic\tmodelling of catalytic three-phase reactors for hydrogenation and oxidation processes

    Directory of Open Access Journals (Sweden)

    Salmi T.

    2000-01-01

    Full Text Available The dynamic modelling principles for typical catalytic three-phase reactors, batch autoclaves and fixed (trickle beds were described. The models consist of balance equations for the catalyst particles as well as for the bulk phases of gas and liquid. Rate equations, transport models and mass balances were coupled to generalized heterogeneous models which were solved with respect to time and space with algorithms suitable for stiff differential equations. The aspects of numerical solution strategies were discussed and the procedure was illustrated with three case studies: hydrogenation of aromatics, hydrogenation of aldehydes and oxidation of ferrosulphate. The case studies revealed the importance of mass transfer resistance inside the catalyst pallets as well as the dynamics of the different phases being present in the reactor. Reliable three-phase reactor simulation and scale-up should be based on dynamic heterogeneous models.

  8. Effect of the Sequence of the Thermoelectric Generator and the Three-Way Catalytic Converter on Exhaust Gas Conversion Efficiency

    Science.gov (United States)

    Su, Chuqi; Tong, Naiqiang; Xu, Yuman; Chen, Shan; Liu, Xun

    2013-07-01

    The potential for thermoelectric exhaust heat recovery in vehicles has increased with recent improvements in the efficiency of thermoelectric generators (TEGs). The problem with using thermoelectric generators for vehicle applications is whether the device is compatible with the original vehicle exhaust system, which determines the quality of the exhaust gas treatment and the realization of energy conservation and emission reduction. Based on ANSYS CFX simulation analysis of the impact of two positional relationships between the TEG and three-way catalytic converter in the exhaust system on the working efficiency of both elements, it is concluded that the layout with the front three-way catalytic converter has an advantage over the other layout mode under current conditions. New ideas for an improvement program are proposed to provide the basis for further research.

  9. A Rapid Process for Fabricating Gas Sensors

    Directory of Open Access Journals (Sweden)

    Chun-Ching Hsiao

    2014-07-01

    Full Text Available Zinc oxide (ZnO is a low-toxicity and environmentally-friendly material applied on devices, sensors or actuators for “green” usage. A porous ZnO film deposited by a rapid process of aerosol deposition (AD was employed as the gas-sensitive material in a CO gas sensor to reduce both manufacturing cost and time, and to further extend the AD application for a large-scale production. The relative resistance change (△R/R of the ZnO gas sensor was used for gas measurement. The fabricated ZnO gas sensors were measured with operating temperatures ranging from 110 °C to 180 °C, and CO concentrations ranging from 100 ppm to 1000 ppm. The sensitivity and the response time presented good performance at increasing operating temperatures and CO concentrations. AD was successfully for applied for making ZnO gas sensors with great potential for achieving high deposition rates at low deposition temperatures, large-scale production and low cost.

  10. Process for production of industrial gas

    Energy Technology Data Exchange (ETDEWEB)

    Maslennikov, V.M.; Gordin, K.A.; Krivokon, A.A.; Nosach, V.G.; Shpil' rain, E.E.; Zholudov, Y.S.

    1981-08-23

    A method for producing gas containing H/sub 2/ and CO from solid fuel in the presence of steam and a high-temperature heat transfer agent at 1500-2500 K with repeated oxidative gasification of the solid residue. The ash-enriched fuel from the 2nd stage is burned in O/sub 2/-containing gas in the 3rd stage. The ash and CO/sub 2/-containing gas are separated, and the gas is returned to the 2nd stage. In the 1st stage the solid fuel is takenin stoichiometric excess for the reaction with steam, and the oxidizing agent in the 2nd stage - in insufficiency; in the 3rd stage the fuel is burned with gas containing excess O/sub 2/ and at a temperature below the melting point of the ash. As the high-temperature heat transfer agent, a portion of the industrial gas preheated to the initial process temperature is used.

  11. Non-catalytic plasma-arc reforming of natural gas with carbon dioxide as the oxidizing agent for the production of synthesis gas or hydrogen - HTR2008-58023

    International Nuclear Information System (INIS)

    The world's energy consumption is increasing constantly due to the growing population of the world. The increasing energy consumption has a negative effect on the fossil fuel reserves of the world. Hydrogen has the potential to provide energy for all our needs by making use of fossil fuel such as natural gas and nuclear-based electricity. Hydrogen can be produced by reforming methane with carbon dioxide as the oxidizing agent. Hydrogen can be produced in a Plasma-arc reforming unit making use of the heat energy generated by a 500 MWt Pebble Bed Modular Reactor (PBMR). The reaction in the unit takes place stoichiometrically in the absence of a catalyst. Steam can be added to the feed stream together with the Carbon Dioxide, which make it possible to control the H2/CO ratio in the synthesis gas between 1/1 and 3/1. This ratio of H2/CO in the synthesis gas is suitable to be used as feed gas to almost any chemical and petrochemical process. To increase the hydrogen production further, the Water-Gas Shift Reaction can be applied. A techno-economic analysis was performed on the non-catalytic plasma-arc reforming process. The capital cost of the plant is estimated at $463 million for the production of 1 132 million Nm3/year of hydrogen. The production cost of hydrogen is in the order of $12.81 per GJ depending on the natural gas cost and the price of electricity. (authors)

  12. Gas phase kinetic and optical emission spectroscopy studies in plasma-enhanced hot filament catalytic CVD production of carbon nanotubes

    International Nuclear Information System (INIS)

    Optical emission spectroscopy (OES) is used as the main experimental tool for comparison with simulations of the plasma and gas phase composition during plasma-enhanced hot filament catalytic chemical vapor deposition (PE HF CCVD) growth of carbon nanotubes (CNTs). Calculated concentration of more than 45 species in model of the CVD reactor is acquired by ChemkinTM software. Study of different conditions is performed and a close relationship can be found between the nature and the growth rate of carbon nanostructures and the concentration of the active gas phase species. Moreover it is shown that significant changes in the density and morphology of the CNTs grown in the presence of NH3 could be mainly explained by the gas phase formation of CN and HCN

  13. Gas phase kinetic and optical emission spectroscopy studies in plasma-enhanced hot filament catalytic CVD production of carbon nanotubes

    Science.gov (United States)

    Guláš, M.; Le Normand, F.; Veis, P.

    2009-03-01

    Optical emission spectroscopy (OES) is used as the main experimental tool for comparison with simulations of the plasma and gas phase composition during plasma-enhanced hot filament catalytic chemical vapor deposition (PE HF CCVD) growth of carbon nanotubes (CNTs). Calculated concentration of more than 45 species in model of the CVD reactor is acquired by Chemkin™ software. Study of different conditions is performed and a close relationship can be found between the nature and the growth rate of carbon nanostructures and the concentration of the active gas phase species. Moreover it is shown that significant changes in the density and morphology of the CNTs grown in the presence of NH 3 could be mainly explained by the gas phase formation of CN and HCN.

  14. Tax issues in structuring gas process arrangements

    International Nuclear Information System (INIS)

    The current status of various tax issues regarding ownership, operation and financing of gas processing facilities in Canada was discussed. Frequently, energy companies are not taxed because of their large pools of un-depreciated capital cost and other resource related accounts. In addition, their time horizons for taxability are being extended in line with the expansion of their businesses. However, other investors are fully taxable, hence they wish to shelter their income through the use of tax efficient investment arrangements. This paper provides a detailed description of the tax treatment of gas processing facilities, tax implications of various structures between the producer and the investor such as lease, processing fee arrangements etc., and use of 'Canadian Renewable and Conservation Expense' (CRCE) for cogeneration projects within processing plants. All these need to be considered before completing a financing transaction involving a gas processing facility, since the manner in which the transaction is completed will determine the advantages and benefits from an income tax perspective. The accounting and legal aspects must be similarly scrutinized to ensure that the intended results for all parties are achieved. 8 figs

  15. Simultaneous probing of bulk liquid phase and catalytic gas-liquid-solid interface under working conditions using attenuated total reflection infrared spectroscopy

    International Nuclear Information System (INIS)

    Design and performance of a reactor set-up for attenuated total reflection infrared (ATR-IR) spectroscopy suitable for simultaneous reaction monitoring of bulk liquid and catalytic solid-liquid-gas interfaces under working conditions are presented. As advancement of in situ spectroscopy an operando methodology for gas-liquid-solid reaction monitoring was developed that simultaneously combines catalytic activity and molecular level detection at the catalytically active site of the same sample. Semi-batch reactor conditions are achieved with the analytical set-up by implementing the ATR-IR flow-through cell in a recycle reactor system and integrating a specifically designed gas feeding system coupled with a bubble trap. By the use of only one spectrometer the design of the new ATR-IR reactor cell allows for simultaneous detection of the bulk liquid and the catalytic interface during the working reaction. Holding two internal reflection elements (IRE) the sample compartments of the horizontally movable cell are consecutively flushed with reaction solution and pneumatically actuated, rapid switching of the cell (<1 s) enables to quasi simultaneously follow the heterogeneously catalysed reaction at the catalytic interface on a catalyst-coated IRE and in the bulk liquid on a blank IRE. For a complex heterogeneous reaction, the asymmetric hydrogenation of 2,2,2-trifluoroacetophenone on chirally modified Pt catalyst the elucidation of catalytic activity/enantioselectivity coupled with simultaneous monitoring of the catalytic solid-liquid-gas interface is shown. Both catalytic activity and enantioselectivity are strongly dependent on the experimental conditions. The opportunity to gain improved understanding by coupling measurements of catalytic performance and spectroscopic detection is presented. In addition, the applicability of modulation excitation spectroscopy and phase-sensitive detection are demonstrated

  16. Phase Composition of Ni/Mg1−xNixO as a Catalyst Prepared for Selective Methanation of CO in H2-Rich Gas

    Directory of Open Access Journals (Sweden)

    Mengmeng Zhang

    2015-01-01

    Full Text Available Supported Ni catalysts Ni/Mg1−xNixO were prepared by reducing samples NiO-MgO in H2/N2 mixture gas at 500°C~800°C for selective methanation of CO in H2-rich gas (CO-SMET. The samples NiO-MgO were obtained by heating water slurry of MgO and Ni(NO32 in a rotary evaporator at 80°C and a final calcination in air at 400°C~800°C. X-ray diffraction (XRD and temperature programmed reduction (TPR measurements demonstrate that the samples NiO-MgO were composed of solid solution Mg1−yNiyO as the main phase and a minor amount of NiO at calcination temperature of 400°C, and amount of the NiO was decreased as calcination temperature increased. Phase composition of the catalysts Ni/Mg1−xNixO was estimated by the Rietveld method. Effects of reduction temperature, feed Ni/Mg ratio, and calcination temperature on phase composition and catalytic activity of the catalysts were investigated. It is clear that CO conversion was generally enhanced by an increased amount of metallic Ni of the catalysts.

  17. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    OpenAIRE

    Solomon, S. J.; Custer, T.; G. Schade; Soares Dias, A. P.; J. Burrows

    2005-01-01

    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...

  18. Hydrogen-rich gas as a product of two-stage co-gasification of lignite/waste mixtures

    Czech Academy of Sciences Publication Activity Database

    Straka, Pavel; Bičáková, Olga

    2014-01-01

    Roč. 39, č. 21 (2014), s. 10987-10995. ISSN 0360-3199 Institutional support: RVO:67985891 Keywords : co-gasification * waste plastics * lignite * hydrogen-rich gas Subject RIV: DM - Solid Waste and Recycling Impact factor: 3.313, year: 2014 http://authors.elsevier.com/sd/article/S0360319914014025

  19. Economics of natural gas conversion processes

    International Nuclear Information System (INIS)

    This paper examines the potential profitability of a selected group of possible natural gas conversion processes from the perspective of a manufacturing entity that has access to substantial low cost natural gas reserves, capital to invest, and no allegiance to any particular product. The analysis uses the revenues and costs of conventional methanol technology as a framework to evaluate the economics of the alternative technologies. Capital requirements and the potential to enhance cash margins are the primary focus of the analysis. The basis of the analysis is a world-scale conventional methanol plant that converts 3.2 Mm3 per day (120 MMSCFD) of natural gas into 3510 metric tonnes (3869 shorts tons) per day of methanol. Capital and operating costs are for an arbitrary remote location where natural gas is available at 0.47 US dollars per GJ (0.50 US dollars per MMBtu). Other costs include ocean freight to deliver the product to market at a US Gulf Coast location. Payout time, which is the ratio of the total capital investment to cash margin (revenue less total operating expenses), is the economic indicator for the analysis. Under these conditions, the payout time for the methanol plant is seven years. The payout time for the alternative natural gas conversion technologies is generally much higher, which indicates that they currently are not candidates for commercialization without consideration of special incentives. The analysis also includes an evaluation of the effects of process yields on the economics of two potential technologies, oxidative coupling to ethylene and direct conversion to methanol. This analysis suggests areas for research focus that might improve the profitability of natural gas conversion. 29 refs., 14 figs., 5 tabs

  20. Adsorption process to recover hydrogen from feed gas mixtures having low hydrogen concentration

    Science.gov (United States)

    Golden, Timothy Christopher; Weist, Jr., Edward Landis; Hufton, Jeffrey Raymond; Novosat, Paul Anthony

    2010-04-13

    A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds to produce a hydrogen-rich product gas from a low hydrogen concentration feed with a high recovery rate. Each of the plurality of adsorption beds subjected to a repetitive cycle. The process comprises an adsorption step for producing the hydrogen-rich product from a feed gas mixture comprising 5% to 50% hydrogen, at least two pressure equalization by void space gas withdrawal steps, a provide purge step resulting in a first pressure decrease, a blowdown step resulting in a second pressure decrease, a purge step, at least two pressure equalization by void space gas introduction steps, and a repressurization step. The second pressure decrease is at least 2 times greater than the first pressure decrease.

  1. China organic-rich shale geologic features and special shale gas production issues

    OpenAIRE

    Yiwen Ju; Guochang Wang; Hongling Bu; Qingguang Li; Zhifeng Yan

    2014-01-01

    The depositional environment of organic-rich shale and the related tectonic evolution in China are rather different from those in North America. In China, organic-rich shale is not only deposited in marine environment, but also in non-marine environment: marine-continental transitional environment and lacustrine environment. Through analyzing large amount of outcrops and well cores, the geologic features of organic-rich shale, including mineral composition, organic matter richness and type, a...

  2. Applications of the water--gas shift reaction. II. Catalytic exchange of deuterium for hydrogen at saturated carbon

    International Nuclear Information System (INIS)

    Previous studies on the homogeneous catalysis of the water-gas shift reaction by metal complexes of groups 6 and 8 had been carried out using aqueous alcoholic solutions of group 8 metal carbonyl complexes made basic with KOH. Substitution of triethylamine (Et3N) for KOH as base and alcohol for solvent led to the discovery that Et3N in the presence of D2O, CO, and Rh6(CO)16 at 1500C undergoes an unusual catalytic exchange of deuterium for hydrogen. A suggested mechanism for this reaction is given and includes activation of hydrogen at a saturated carbon

  3. Random processes and geographic species richness patterns : why so few species in the north?

    NARCIS (Netherlands)

    Bokma, F; Bokma, J; Monkkonen, M

    2001-01-01

    In response to the suggestion that the latitudinal gradient in species richness is the result of stochastic processes of species distributions, we created a computer simulation program that enabled us to study random species distributions over irregularly shaped areas. Our model could not explain la

  4. Introduction to gas lasers with emphasis on selective excitation processes

    CERN Document Server

    Willett, Colin S

    1974-01-01

    Introduction to Gas Lasers: Population Inversion Mechanisms focuses on important processes in gas discharge lasers and basic atomic collision processes that operate in a gas laser. Organized into six chapters, this book first discusses the historical development and basic principles of gas lasers. Subsequent chapters describe the selective excitation processes in gas discharges and the specific neutral, ionized and molecular laser systems. This book will be a valuable reference on the behavior of gas-discharge lasers to anyone already in the field.

  5. The transformation and quenching of simulated gas-rich dwarf satellites within a group environment

    CERN Document Server

    Yozin, Cameron

    2015-01-01

    The underlying mechanisms driving the quenching of dwarf-mass satellite galaxies remain poorly constrained, but recent studies suggest they are particularly inefficient for those satellites with stellar mass 10$^{\\rm 9}$ M$_{\\odot}$. We investigate the characteristic evolution of these systems with chemodynamical simulations and idealised models of their tidal/hydrodynamic interactions within the 10$^{\\rm 13-13.5}$ M$_{\\odot}$ group-mass hosts in which they are preferentially quenched. Our fiducial simulations highlight the role played by secular star formation and stellar bars, and demonstrate a transition from a gas-rich to passive, HI-deficient state (i.e. $\\Delta$SFR$\\le$-1, def$_{\\rm HI}$$\\ge$0.5) within 6 Gyr of first infall. Furthermore, in the 8-10 Gyr in which these systems have typically been resident within group hosts, the bulge-to-total ratio of an initially bulgeless disc can increase to 0.3$<$B/T$<$0.4, its specific angular momentum $\\lambda_{\\rm R}$ reduce to $\\sim$0.5, and strong bisymm...

  6. Sulfur Isotopes in Gas-rich Impact-Melt Glasses in Shergottites

    Science.gov (United States)

    Rao, M. N.; Hoppe, P.; Sutton, S. R.; Nyquist, Laurence E.; Huth, J.

    2010-01-01

    Large impact melt glasses in some shergottites contain huge amounts of Martian atmospheric gases and they are known as gas-rich impact-melt (GRIM) glasses. By studying the neutron-induced isotopic deficits and excesses in Sm-149 and Sm-150 isotopes resulting from Sm-149 (n,gamma) 150Sm reaction and 80Kr excesses produced by Br-79 (n,gamma) Kr-80 reaction in the GRIM glasses using mass-spectrometric techniques, it was shown that these glasses in shergottites EET79001 and Shergotty contain regolith materials irradiated by a thermal neutron fluence of approx.10(exp 15) n/sq cm near Martian surface. Also, it was shown that these glasses contain varying amounts of sulfates and sulfides based on the release patterns of SO2 (sulfate) and H2S (sulfide) using stepwise-heating mass-spectrometric techniques. Furthermore, EMPA and FE-SEM studies in basaltic-shergottite GRIM glasses EET79001, LithB (,507& ,69), Shergotty (DBS I &II), Zagami (,992 & ,994) showed positive correlation between FeO and "SO3" (sulfide + sulfate), whereas those belonging to olivine-phyric shergottites EET79001, LithA (,506, & ,77) showed positive correlation between CaO/Al2O3 and "SO3".

  7. Experimental and modeling study of the effect of CH(4) and pulverized coal on selective non-catalytic reduction process.

    Science.gov (United States)

    Zhang, Yanwen; Cai, Ningsheng; Yang, Jingbiao; Xu, Bo

    2008-10-01

    The reduction of nitric oxide using ammonia combined with methane and pulverized coal additives has been studied in a drop tube furnace reactor. Simulated flue gas with 1000 ppm NO(x) and 3.4% excess oxygen was generated by cylinder gas. Experiments were performed in the temperature range of 700-1200 degrees C to investigate the effects of additives on the DeNO(x) performance. Subsequently, a kinetic mechanism was modified and validated based on experimental results, and a computational kinetic modeling with CHEMKIN was conducted to analyze the secondary pollutants. For both methane and pulverized coal additives, the temperature window is shifted towards lower temperatures. The appropriate reaction temperature is shifted to about 900 and 800 degrees C, respectively with 1000 ppm methane and 0.051 g min(-1) pulverized lignite coal. The addition of methane and pulverized coal widens the temperature window towards lower temperature suggesting a low temperature application of the process. Furthermore, selective non-catalytic reduction (SNCR) reaction rate is accelerated evidently with additives and the residence time to complete the reaction is shortened distinctly. NO(x) reduction efficiency with 80% is achieved in about 0.3s without additive at 1000 degrees C. However, it is achieved in only about 0.2s with 100 ppm methane as additive, and only 0.07 and 0.05s are needed respectively for the cases of 500 and 1000 ppm methane. The modified kinetic modeling agrees well with the experimental results and reveals additional information about the process. Investigation on the byproducts where NO(2) and N(2)O were analyzed by modeling and the others were investigated by experimental means indicates that emissions would not increase with methane and pulverized coal additions in SNCR process and the efficacious temperature range of SNCR reaction is widened approximately with 100 degrees C. PMID:18727998

  8. An extremely optically dim tidal feature in the gas-rich interacting galaxy group NGC 871/NGC 876/NGC 877

    CERN Document Server

    Lee-Waddell, K; Cuillandre, J -C; Cannon, J; Haynes, M P; Sick, J; Chandra, P; Patra, N; Stierwalt, S; Giovanelli, R

    2014-01-01

    We present GMRT HI observations and deep CFHT MegaCam optical images of the gas-rich interacting galaxy group NGC 871/NGC 876/NGC 877 (hereafter NGC 871/6/7). Our high-resolution data sets provide a census of the HI and stellar properties of the detected gas-rich group members. In addition to a handful of spiral, irregular and dwarf galaxies, this group harbours an intriguing HI feature, AGC 749170, that has a gas mass of ~10^9.3 M_sol, a dynamical-to-gas mass ratio of ~1 (assuming the cloud is rotating and in dynamical equilibrium) and no optical counterpart in previous imaging. Our observations have revealed a faint feature in the CFHT g'- and r'-bands; if it is physically associated with AGC 749170, the latter has M/L_g > 1000 M_sol/L_sol as well as a higher metallicity (estimated using photometric colours) and a significantly younger stellar population than the other low-mass gas-rich group members. These properties, as well as its spectral and spatial location with respect to its suspected parent galaxie...

  9. Relaxation processes in mixed gas dynamic lasers

    Energy Technology Data Exchange (ETDEWEB)

    Soloukhin, R.I.; Fomin, N.A.

    1978-12-01

    With the solution of gasdynamic and CO/sub 2/--N/sub 2/ vibrational relaxation equations, analysis was made of vibrational energy losses associated with relaxation processes in an inverted molecular system with selective thermal excitation and supersonic flow mixing of the pumping and radiative gas components. Optimum operation conditions were determined, and a possibility of regimes with low vibrational losses was found to be feasible at available specific energies up to 200 J/g.

  10. Simulation of thermoelectric microgenerator with gas-fueled catalytic heat source

    Directory of Open Access Journals (Sweden)

    Strutynska L.T.

    2008-04-01

    Full Text Available Physical model of semiconductor thermoelectric microgenerator with a catalytic heat source is created and investigated. Method for optimization of its parameters with regard to heat exchange system, structural characteristics and thermopile properties is described. The proposed model is used for the development and future creation of self-contained power sources for electronic equipment.

  11. Simulation of thermoelectric microgenerator with gas-fueled catalytic heat source

    OpenAIRE

    Strutynska L.T.

    2008-01-01

    Physical model of semiconductor thermoelectric microgenerator with a catalytic heat source is created and investigated. Method for optimization of its parameters with regard to heat exchange system, structural characteristics and thermopile properties is described. The proposed model is used for the development and future creation of self-contained power sources for electronic equipment.

  12. A discussion on gas sources of the Feixianguan Formation H2S-rich giant gas fields in the northeastern Sichuan Basin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In recent years several H2S-rich oolite giant gas pools have been discovered in the Lower Triassic Feixianguan Formation of the northeastern Sichuan basin, and their explored gas reserves have been over 5000x108 m3. However, gas sources remain unsolved due to multiple source horizons with high maturity in this area and TSR alterations. By integrating analytical data of natural gas samples with conprehensive investigations on many factors, such as oil-gas geology, distribution and evolution of source rocks, charging and adjustment of gas pools, mixture of natural gases and secondery alterations, the present study concluded that the dominant source for the Feixianguan Fr. gas pools is the Permian Longtan Fr. source rock and secondly the Silurian Longmaxi Fr. source rock. Natural gases from the various gas pools differ genetically due to the matching diversity of seal configurations with phases of hydrocarbon generation and expulsion by different source rocks, among which natural gases in Puguang Gasfield are dominated by the trapped gas generated from the Longtan Fr. source rock and commingled with the gas cracked from the Silurian crude oil, while those in Dukouhe,Tieshangpo and Luojiazhai Gasfields are composed mainly of the Silurian oil-cracking gas and commingled with the natural gas derived from the Longtan Fr. source rock.

  13. Reforming of methane in tubes with a catalytic active wall

    International Nuclear Information System (INIS)

    The heterogeneous steam reforming process in tubes with catalytic active inner surface is studied. The purpose of this ivestigation is to find a method of predicting the reaction rate of the catalytic conversion of methane by steam. The dependency of the reaction rate upon the temperature, pressure, gas composition, Reynolds number, geometrical sizes of tubes and catalytic behaviour of the catalytic active inner wall of these tubes has been examined. It was found that the reaction rate mainly depends on the temperature. The reaction rate is limited by the catalytic behaviour and the heat resisting properties of the materials used. (author)

  14. Summary on Characteristics and Applications for Low -Carbon Catalytic Combustion of Natural Gas%天然气低碳催化燃烧特性与应用*

    Institute of Scientific and Technical Information of China (English)

    张世红; Valerie Dupont; Alan Williams

    2013-01-01

    Lower activation energies of combustion reaction allows reactions occurring at very small hydrocarbons concentration in air, therefore the adiabatic reaction temperature is very low and below the threshold of NOx formation. Oxidation can be complete even when at extremely small fuel concentrations in air, therefore products--CO and unburned hydrocarbons of incomplete combustion do not form. Combustion can occur outside of normal gas phase flammability limits, therefore the combustion can be more stable. According to the modelling results obtained with the detailed chemical mechanism, the Pt surface reactions inhibited in several ways the extent of the gas-phase oxidation and increased the surface temperature of homogeneous ignition. Due to the theory, several catalytic combustion burners of natural gas were designed and studied. The operating conditions verified "near zero" pollutant emissions that only a catalytic combustion process can achieve at present. As low-carbon strategies, the application prospect of national gas catalytic combustion boiler, oven and furnace were discussed.%  催化燃烧反应较低的活化能容许反应在贫碳氢化合物浓度下发生,因此绝热反应的温度低于NOx形成的限制,并完全氧化,不形成CO和未完全燃烧的碳氢化合物,燃烧发生在常规气相易燃极限之外,因此燃烧更加稳定。根据分步化学机理方法模拟出的结果可以得出,铂表面的异相反应抑制了气相氧化反应的程度,并且提高了单相点燃的表面温度。在此理论的指导下,进行了多种天然气催化燃烧装置的设计和研究,催化燃烧过程可达到近零污染排放。作为低碳战略,对天然气催化燃烧锅炉、烤箱和炉窑的应用前景进行了讨论。

  15. Electrical behaviour of catalytic nanostructured CeO2/CuO x composites under air-methane gas impulses

    International Nuclear Information System (INIS)

    Nanostructured composites based on copper oxide and cerium dioxide phases [CuO-CeO2] were elaborated from sol-gel route, with weight fractions of CuO phase ranging between 0 and 0.4. They are interesting potential catalysts allowing conversion of CH4 and CO into CO2 and H2O and might be used in miniaturized gas sensors. An electrical study of this nanostructured system was carried out to determine catalytic behaviours under air-methane impulses at 350 oC. The electrical analysis was based on a specific homemade electronic device. Time dependent interactions between gas pulses and solid catalyst (CuO/CeO2) were analyzed from a frequency modification of the electronic device. Kinetic parameters were determined from a model describing adsorption and desorption of gases adapted to short interaction time between gas and solid. These time dependent electrical behaviours were then correlated with infrared spectroscopy analyses allowing time dependent analysis of methane conversion into CO2 gas, for long interaction time between gas and solid

  16. Demonstration of an integrated catalytic SO2/NOx/particulate removal process

    International Nuclear Information System (INIS)

    A new technology for the integrated catalytic removal of SO2, NOx and particulate has been developed in Europe and will be demonstrated at the Ohio Edison Niles Plant - Unit 2 in Niles, Ohio as part of the Department of Energy Clean Coal Technology Program II. Two applications of this process, one 30 MW industrial and one 300 MW utility are currently under construction in Italy and Denmark, respectively. Pilot scale applications of this technology have yielded greater than 95% removal of both sulfur dioxide (SO2) and nitrogen oxides (NO4). Particulate emissions of less than 1 mg/Nm3 (0.0004 gr/SCF) are inherent to the process. Salable, technical grade sulfuric acid and usable heat are the only by-products. Ammonia, used to reduce nitrogen oxides, is the only reagent required. This demonstration project will treat a 35 MW equivalent slipstream from a 108 MW boiler burning 3.2% sulfur Ohio coal. The objectives of this four year project are to demonstrate the process using U.S. high sulfur coal, verify the scale-up potential of pilot plant results, further quantify and qualify the consumables and products of the process and verify the predicted low O and M costs. This paper describes the WSA-SNOX process and the Niles Demonstration project. The two-year testing program to assess the performance and economic competitiveness of the process is outlined and a brief discussion of estimated full-scale costs is also presented

  17. The top 50 commodity chemicals: Impact of catalytic process limitations on energy, environment, and economics

    Energy Technology Data Exchange (ETDEWEB)

    Tonkovich, A.L.Y.; Gerber, M.A.

    1995-08-01

    The production processes for the top 50 U.S. commodity chemicals waste energy, generate unwanted byproducts, and require more than a stoichiometric amount of feedstocks. Pacific Northwest Laboratory has quantified this impact on energy, environment, and economics for the catalytically produced commodity chemicals. An excess of 0.83 quads of energy per year in combined process and feedstock energy is required. The major component, approximately 54%, results from low per-pass yields and the subsequent separation and recycle of unreacted feedstocks. Furthermore, the production processes, either directly or through downstream waste treatment steps, release more than 20 billion pounds of carbon dioxide per year to the environment. The cost of the wasted feedstock exceeds 2 billion dollars per year. Process limitations resulting from unselective catalysis and unfavorable reaction thermodynamic constraints are the major contributors to this waste. Advanced process concepts that address these problems in an integrated manner are needed to improve process efficiency, which would reduce energy and raw material consumption, and the generation of unwanted byproducts. Many commodity chemicals are used to produce large volume polymer products. Of the energy and feedstock wasted during the production of the commodity chemicals, nearly one-third and one-half, respectively, represents chemicals used as polymer precursors. Approximately 38% of the carbon dioxide emissions are generated producing polymer feedstocks.

  18. New devices Si-rich and C-rich a-Si1−xCx thin films gas sensors based

    International Nuclear Information System (INIS)

    Highlights: •Elaboration of Si-rich and C-rich thin films of amorphous silicon carbide. •Using a co-sputtering d.c magnetron of Si target and different 32–86 of 6H–SiC sprigs. •Structural and optical properties has been performed with applications in environmental field. •Different devices structures based on thin films have been investigated as gas sensor. -- Abstract: In this paper, we present an experimental study on elaboration of Si-rich and C-rich thin films of hydrogenated amorphous silicon carbide (a-Si1−xCx:H) using a DC magnetron co-sputtering of Si single crystal target on which are deposited different polycrystalline 6H–SiC sprigs varying from 32 to 86, with dimension of 10 × 5 mm2. A comparative study of structural and optical properties has been performed and its applications in environmental field. The a-Si1−xCx:H films were investigated by scanning electron microscopy (SEM), UV–visible-NIR spectrophotometry, infrared absorption spectroscopy, secondary ion mass spectrometry (SIMS), and photoluminescence. The measured optical gap of a-Si1−xCx:H thin films depend on the carbon concentration with x varying from 0.18 to 0.30. This can be probably explained by the changes of Sp3 (silicon or film with low carbon content) to sp2 (high carbon content) configuration. Finally, different devices structures based the thin films have been investigated as gas sensors as Pd/a-Si0.72C0.28:H with a good sensitivity of CO2 and H2 gases at low bias voltage ranging from 0.05 to 0.26 volt, respectively and a low response time of 29 s and 25 s was obtained at 165 ppm of the used gases, with a recovery time of 32 s and 23 s for CO2 and H2 gases, respectively

  19. A thermogravimetric analysis (TGA) method to determine the catalytic conversion of cellulose from carbon-supported hydrogenolysis process

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Glauco F. [Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), C.P. 6192, 13083-970 Campinas, SP (Brazil); Institute of Chemistry of São Carlos (IQSC), University of São Paulo (USP), C.P. 780, CEP 13560-970 São Carlos, SP (Brazil); Ramos, Luiz A. [Institute of Chemistry of São Carlos (IQSC), University of São Paulo (USP), C.P. 780, CEP 13560-970 São Carlos, SP (Brazil); Barrett, Dean H. [Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), C.P. 6192, 13083-970 Campinas, SP (Brazil); Curvelo, Antonio Aprígio S. [Institute of Chemistry of São Carlos (IQSC), University of São Paulo (USP), C.P. 780, CEP 13560-970 São Carlos, SP (Brazil); Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center for Research in Energy and Materials (CNPEM), C.P. 6179, 13083-970 Campinas, SP (Brazil); Rodella, Cristiane B., E-mail: cristiane.rodella@lnls.br [Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), C.P. 6192, 13083-970 Campinas, SP (Brazil)

    2015-09-20

    Graphical abstract: - Highlights: • A new method to determine the catalytic conversion of cellulose using TGA has been developed. • TGA is able to differentiate between carbon from cellulose and carbon from the catalyst. • Building an analytical curve from TGA results enables the accurate determination of cellulose conversion. - Abstract: The ability to determine the quantity of solid reactant that has been transformed after a catalytic reaction is fundamental in accurately defining the conversion of the catalyst. This quantity is also central when investigating the recyclability of a solid catalyst as well as process control in an industrial catalytic application. However, when using carbon-supported catalysts for the conversion of cellulose this value is difficult to obtain using only a gravimetric method. The difficulty lies in weighing errors caused by loss of the solid mixture (catalyst and non-converted cellulose) after the reaction and/or moisture adsorption by the substrate. These errors are then propagated into the conversion calculation giving erroneous results. Thus, a quantitative method using thermogravimetric analysis (TGA) has been developed to determine the quantity of cellulose after a catalytic reaction by using a tungsten carbide catalyst supported on activated carbon. Stepped separation of TGA curves was used for quantitative analysis where three thermal events were identified: moisture loss, cellulose decomposition and CO/CO{sub 2} formation. An analytical curve was derived and applied to quantify the residual cellulose after catalytic reactions which were performed at various temperatures and reaction times. The catalytic conversion was calculated and compared to the standard gravimetric method. Results showed that catalytic cellulose conversion can be determined using TGA and exhibits lower uncertainty (±2%) when compared to gravimetric determination (±5%). Therefore, it is a simple and relatively inexpensive method to determine

  20. A thermogravimetric analysis (TGA) method to determine the catalytic conversion of cellulose from carbon-supported hydrogenolysis process

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • A new method to determine the catalytic conversion of cellulose using TGA has been developed. • TGA is able to differentiate between carbon from cellulose and carbon from the catalyst. • Building an analytical curve from TGA results enables the accurate determination of cellulose conversion. - Abstract: The ability to determine the quantity of solid reactant that has been transformed after a catalytic reaction is fundamental in accurately defining the conversion of the catalyst. This quantity is also central when investigating the recyclability of a solid catalyst as well as process control in an industrial catalytic application. However, when using carbon-supported catalysts for the conversion of cellulose this value is difficult to obtain using only a gravimetric method. The difficulty lies in weighing errors caused by loss of the solid mixture (catalyst and non-converted cellulose) after the reaction and/or moisture adsorption by the substrate. These errors are then propagated into the conversion calculation giving erroneous results. Thus, a quantitative method using thermogravimetric analysis (TGA) has been developed to determine the quantity of cellulose after a catalytic reaction by using a tungsten carbide catalyst supported on activated carbon. Stepped separation of TGA curves was used for quantitative analysis where three thermal events were identified: moisture loss, cellulose decomposition and CO/CO2 formation. An analytical curve was derived and applied to quantify the residual cellulose after catalytic reactions which were performed at various temperatures and reaction times. The catalytic conversion was calculated and compared to the standard gravimetric method. Results showed that catalytic cellulose conversion can be determined using TGA and exhibits lower uncertainty (±2%) when compared to gravimetric determination (±5%). Therefore, it is a simple and relatively inexpensive method to determine catalytic

  1. Production of a gas rich in hydrogen from gasification of biomass

    International Nuclear Information System (INIS)

    The gasification consists in a thermal transformation of a strong fuel (coal, peat, wood...) in presence of a sparkling compound (O2, air, CO, steam of water...). The goal of this transformation is generally to convert the strong in view of the obtaining of a combustible sparkling mixture. She/it distinguishes herself/itself therefore of the pyrolysis, thermal operation taking place in the absence of gas reacting with the strong follows a partial oxidation of pyrolysis products in presence of oxygen or air to a temperature of 600 to 1.000 C. One gets a gas satisfying the CO, of the CO2, of the H2.... The generated gas is a fuel that can be used then in furnaces or purified and used in turbines to room of combustion and batteries to fuels. This transformation puts in game a set of thermochemical mechanisms, pyrolysis, oxidation and reduction, greatly coupled, that condition the working of a gasification process and whose optimization imposes the technological constraints of which some are only raised partially at this day. (authors)

  2. Emerging environmental issues for gas processing plants

    International Nuclear Information System (INIS)

    An overview of emerging environmental issues of interest to the construction and ongoing management of gas processing plants was provided. Recent responses by the Alberta Energy and Utilities Board (AEUB) to certain environmental concerns, initiatives of Alberta Environmental Protection (AEP), and evolving developments by the federal government with respect to air quality issues are emphasized. AEUB''s specific responsibilities for air quality, incinerator stack emissions, flaring, fugitive emissions, sulphur recovery, soil and groundwater contamination, noise and emergency response support for upstream petroleum industry incidents and associated hazards are reviewed. A case study of Shell Oil''s Caroline application for increased throughput at its Caroline sour gas plant was discussed to illustrate the AEUB''s application of its on environmental protection mandate

  3. Catalytic enantioselective OFF ↔ ON activation processes initiated by hydrogen transfer: concepts and challenges.

    Science.gov (United States)

    Quintard, Adrien; Rodriguez, Jean

    2016-08-18

    Hydrogen transfer initiated processes are eco-compatible transformations allowing the reversible OFF ↔ ON activation of otherwise unreactive substrates. The minimization of stoichiometric waste as well as the unique activation modes provided by these transformations make them key players for a greener future for organic synthesis. Long limited to catalytic reactions that form racemic products, considerable progress on the development of strategies for controlling diastereo- and enantioselectivity has been made in the last decade. The aim of this review is to present the different strategies that enable enantioselective transformations of this type and to highlight how they can be used to construct key synthetic building blocks in fewer operations with less waste generation. PMID:27381644

  4. Copper/bamboo fabric composite prepared via a silver catalytic electroless deposition process for electromagnetic shielding

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Qian; Lu, Yinxiang [Fudan Univ., Shanghai (China). Dept. of Materials Science

    2013-09-15

    Copper/bamboo fabric composite prepared via a silver catalytic electroless plating process is reported. The microstructure of the composite was analyzed by means of scanning electron microscopy, which illustrated that the copper coating was composed of spherical particles and clusters. The composition and chemical state of the metal layer were measured using X-ray diffraction and energy-dispersive X-ray analysis spectra; copper and a small amount of nickel were detected. Mechanical properties were measured based on a standard (ISO 13934-1:1999) for the fabrics with and without copper coating. The breaking force for the composite was improved by about 16.8% compared to uncoated bamboo fabric. The electromagnetic interference shielding effectiveness of the composite was more than 40 dB at frequencies ranging from 0.2 to 1000MHz. The copper coating on bamboo fabric passed the Scotch {sup registered} -tape test. (orig.)

  5. Vapour Treatment Method Against Other Pyro- and Hydrometallurgical Processes Applied to Recover Platinum From Used Auto Catalytic Converters

    Institute of Scientific and Technical Information of China (English)

    Agnieszka FORNALCZYK; Mariola SATERNUS

    2013-01-01

    Today more and more cars are produced every year.All of them have to be equipped with catalytic converters,the main role of which is to obtain substances harmless to the environment instead of exhausted gases.Catalytic converters contain platinum group metals (PGM) especially platinum,palladium and rhodium.The price of these metals and their increasing demand are the reasons why today it is necessary to recycle used auto catalytic converters.There are many available methods of recovering PGM metals from them,especially platinum.These methods used mainly hydrometallurgical processes; however pyrometallurgical ones become more and more popular.The article presents results of the research mainly concerning pyrometallurgical processes.Two groups of research were carried out.In the first one different metals such as lead,magnesium and copper were used as a metal collector.During the tests,platinum went to those metals forming an alloy.In other research metal vapours were blown through catalytic converter carrier (grinded or whole).In the tests metals such as calcium,magnesium,cadmium and zinc were applied.As a result white or grey powder (metal plus platinum) was obtained.The tables present results of the research.Processing parameters and conclusions are also shown.To compare efficiency of pyrometallurgical and hydrometallurgical methods catalytic converter carrier and samples of copper with platinum obtained from pyrometallurgical method were solved in aqua regia,mixture of aqua regia and fluoric acid.

  6. Cr(VI) Generation During Flaring of CO-Rich Off-Gas from Closed Ferrochromium Submerged Arc Furnaces

    Science.gov (United States)

    du Preez, S. P.; Beukes, J. P.; van Zyl, P. G.

    2015-04-01

    Ferrochromium (FeCr) is the only source of new Cr units used in stainless steel production, which is a vital modern day alloy, making FeCr equally important. Small amounts of Cr(VI) are unintentionally formed during several FeCr production steps. One such production step is the flaring of CO-rich off-gas from closed submerged arc furnaces (SAF), for which Cr(VI) formation is currently not quantified. In this study, the influence of flaring temperature, size of the particles passing through the flare, and retention time within the flame were investigated by simulating the process on laboratory scale with a vertical tube furnace. Multiple linear regression (MLR) analysis was conducted on the overall dataset obtained, which indicated that retention time had the greatest impact on pct Cr(VI) conversion, followed by particle size and temperature. The MLR analysis also yielded an optimum mathematical solution, which could be used to determine the overall impact of these parameters on pct Cr(VI) conversion. This equation was used to determine realistic and unrealistic worst-case scenario pct Cr(VI) conversions for actual FeCr SAFs, which yielded 2.7 × 10-2 and 3.5 × 10-1 pct, respectively. These values are significantly lower than the current unsubstantiated pct Cr(VI) conversion used in environmental impact assessments for FeCr smelters, i.e., 0.8 to 1 pct.

  7. The production of proton-rich isotopes beyond iron: The $\\gamma$ process in stars

    CERN Document Server

    Pignatari, Marco; Reifarth, René; Travaglio, Claudia

    2016-01-01

    Beyond iron, a small fraction of the total abundances in the Solar System is made of proton-rich isotopes, the p nuclei. The clear understanding of their production is a fundamental challenge for nuclear astrophysics. The p nuclei constrain the nucleosynthesis in core-collapse and thermonuclear supernovae. The $\\gamma$ process is the most established scenario for the production of the p nuclei, which are produced via different photodisintegration paths starting on heavier nuclei. A large effort from nuclear physics is needed to access the relevant nuclear reaction rates far from the valley of stability. This review describes the production of the heavy proton-rich isotopes by the $\\gamma$ process in stars, and explores the state of the art of experimental nuclear physics to provide nuclear data for stellar nucleosynthesis.

  8. The production of proton-rich isotopes beyond iron: The γ-process in stars

    Science.gov (United States)

    Pignatari, Marco; Göbel, Kathrin; Reifarth, René; Travaglio, Claudia

    2016-04-01

    Beyond iron, a small fraction of the total abundances in the Solar System is made of proton-rich isotopes, the p-nuclei. The clear understanding of their production is a fundamental challenge for nuclear astrophysics. The p-nuclei constrain the nucleosynthesis in core-collapse and thermonuclear supernovae. The γ-process is the most established scenario for the production of the p-nuclei, which are produced via different photodisintegration paths starting on heavier nuclei. A large effort from nuclear physics is needed to access the relevant nuclear reaction rates far from the valley of stability. This review describes the production of the heavy proton-rich isotopes by the γ-process in stars, and explores the state of the art of experimental nuclear physics to provide nuclear data for stellar nucleosynthesis.

  9. Chemical Processing in High-Pressure Aqueous Environments. 9. Process Development for Catalytic Gasification of Algae Feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Douglas C.; Hart, Todd R.; Neuenschwander, Gary G.; Rotness, Leslie J.; Olarte, Mariefel V.; Zacher, Alan H.

    2012-07-26

    Through the use of a metal catalyst, gasification of wet algae slurries can be accomplished with high levels of carbon conversion to gas at relatively low temperature (350 C). In a pressurized-water environment (20 MPa), near-total conversion of the organic structure of the algae to gases has been achieved in the presence of a supported ruthenium metal catalyst. The process is essentially steam reforming, as there is no added oxidizer or reagent other than water. In addition, the gas produced is a medium-heating value gas due to the synthesis of high levels of methane, as dictated by thermodynamic equilibrium. As opposed to earlier work, biomass trace components were removed by processing steps so that they did not cause processing difficulties in the fixed catalyst bed tubular reactor system. As a result, the algae feedstocks, even those with high ash contents, were much more reliably processed. High conversions were obtained even with high slurry concentrations. Consistent catalyst operation in these short-term tests suggested good stability and minimal poisoning effects. High methane content in the product gas was noted with significant carbon dioxide captured in the aqueous byproduct in combination with alkali constituents and the ammonia byproduct derived from proteins in the algae. High conversion of algae to gas products was found with low levels of byproduct water contamination and low to moderate loss of carbon in the mineral separation step.

  10. Gas mixing processes in nuclear AGR boilers

    International Nuclear Information System (INIS)

    To ensure the safe operation and control of Nuclear (A.G.R.) boilers, 2-D computational models are currently under development. The aim of these models is to predict the flow and temperature distribution of the gas and water side under different operational conditions. These models are based on numerical solutions of the 2-D flow and heat transfer equations for turbulent flow in boilers. Measurements on a closely pitched tube bank with water cooling have demonstrated considerable discrepancies between experimental results and computer predictions. This investigation is therefore being carried out to study theoretically and experimentally the flow and heat transfer process under such a boiler condition. A two dimensional computer model has been developed which incorporates the effects of gas mixing and the interactions between the gas and water side. To cover the complete heat exchanger the governing equations are written in the lumped parameter form. The governing equations have been solved by a computer code written in FORTRAN-77. To test the validity of this model, the computer predictions have been compared with experimental results. Results to date indicate reasonable agreement with experiment and a further refinement of the computer model is indicated. (author)

  11. Richness and species composition of ants in the recovery process of a gully erosion

    OpenAIRE

    Gabriel Biagiotti; José Aldo Alves Pereira; Carla Rodrigues Ribas; Vanesca Korasaki; Ronald Zanetti; Antônio César Medeiros de Queiroz

    2013-01-01

    This study aimed to determine how the richness and composition of ant species behaves with changes in the recovery process of a gully erosion. The study area has 0.9 hectares subdivided into three sections called sector: "A", "B" and "C". For the definition of the sectors, erosive and natural restoring were taken as the base level of activity. Four transects were laid systematically throughout the area and surrounding compound with forest and grassland. Each transect had three "pitfall trap" ...

  12. Technical and operational feasibility of psychrophilic anaerobic digestion biotechnology for processing ammonia-rich waste

    International Nuclear Information System (INIS)

    Highlights: • Long-term anaerobic digestion (AD) process at high-ammonia (>5 gN/L) is limited. • PADSBR technology was validated to treat N-rich waste with 8.2 ± 0.3 gNH3-N/L. • Excess ammonia (8.2 gN/L) did not affect the digestion process with no inhibition. • VFA, an indicator for process stability, did not accumulate in PADSBR. • Biomass acclimation in PADSBR ensured a high-stabilization of the AD process. - Abstract: Ammonia nitrogen plays a critical role in the performance and stability of anaerobic digestion (AD) of ammonia rich wastes like animal manure. Nevertheless, inhibition due to high ammonia remains an acute limitation in AD process. A successful long-term operation of AD process at high ammonia (>5 gN/L) is limited. This study focused on validating technical feasibility of psychrophilic AD in sequencing batch reactor (PADSBR) to treat swine manure spiked with NH4Cl up to 8.2 ± 0.3 gN/L, as a representative of N-rich waste. CODt, CODs, VS removals of 86 ± 3, 82 ± 2 and 73 ± 3% were attained at an OLR of 3 gCOD/L.d, respectively. High-ammonia had no effect on methane yields (0.23 ± 0.04 L CH4/gTCODfed) and comparable to that of control reactors, which fed with raw swine manure alone (5.5 gN/L). Longer solids/hydraulic retention times in PADSBRs enhanced biomass acclimation even at high-ammonia. Thus VFA, an indicator for process stability, did not accumulate in PADSBR. Further investigation is essential to establish the maximum concentrations of TKN and free ammonia that the PADSBR can sustain

  13. Measurements of flow parameters and decompression wave speed following rupture of rich gas pipelines, and comparison with GASDECOM

    International Nuclear Information System (INIS)

    Measurements of flow parameters and decompression wave speeds in a conventional gas mixture and two other rich gas mixtures following rupture of a high-pressure pipe have been conducted. A test rig, consisting of a stainless steel expansion tube (internal diameter ∼50 mm), has been used to give a length to diameter ratio of 3440 representing a long section of a pipeline. Pressure- and temperature-time traces obtained with high-frequency response transducers have been collected at various locations close to rupture and along the length of the tube. Tests were conducted at three pressure levels: 10, 14 and 20 MPa and at temperatures as low as -25 deg. C. Results indicate good agreement between measured and predicted decompression wave speed by GASDECOM. Additionally, gas temperature-time traces were also measured at different locations along the expansion tube. Since the temperature probes are not as fast in their response, a technique has been developed to reconcile the actual gas temperature from the measured data. The paper presents example results for lean, medium and rich gas mixtures at different initial conditions

  14. On the processes generating latitudinal richness gradients: identifying diagnostic patterns and predictions

    Energy Technology Data Exchange (ETDEWEB)

    Hurlbert, Allen H.; Stegen, James C.

    2014-12-02

    Many processes have been put forward to explain the latitudinal gradient in species richness. Here, we use a simulation model to examine four of the most common hypotheses and identify patterns that might be diagnostic of those four hypotheses. The hypotheses examined include (1) tropical niche conservatism, or the idea that the tropics are more diverse because a tropical clade origin has allowed more time for diversification in the tropics and has resulted in few species adapted to extra-tropical climates. (2) The productivity, or energetic constraints, hypothesis suggests that species richness is limited by the amount of biologically available energy in a region. (3) The tropical stability hypothesis argues that major climatic fluctuations and glacial cycles in extratropical regions have led to greater extinction rates and less opportunity for specialization relative to the tropics. (4) Finally, the speciation rates hypothesis suggests that the latitudinal richness gradient arises from a parallel gradient in rates of speciation. We found that tropical niche conservatism can be distinguished from the other three scenarios by phylogenies which are more balanced than expected, no relationship between mean root distance and richness across regions, and a homogeneous rate of speciation across clades and through time. The energy gradient, speciation gradient, and disturbance gradient scenarios all exhibited phylogenies which were more imbalanced than expected, showed a negative relationship between mean root distance and richness, and diversity-dependence of speciation rate estimates through time. Using Bayesian Analysis of Macroevolutionary Mixtures on the simulated phylogenies, we found that the relationship between speciation rates and latitude could distinguish among these three scenarios. We emphasize the importance of considering multiple hypotheses and focusing on diagnostic predictions instead of predictions that are consistent with more than one hypothesis.

  15. High-performance polymers from nature: catalytic routes and processes for industry.

    Science.gov (United States)

    Walther, Guido

    2014-08-01

    It is difficult to imagine life today without polymers. However, most chemicals are almost exclusively synthesized from petroleum. With diminishing oil reserves, establishing an industrial process to transform renewables into high-value chemicals may be more challenging than running a car without gasoline. This is due to the difficulty in setting up processes that are novel, profitable, and environmentally benign at the same time. Additionally, the quest for sustainability of renewable resources should be based on incorporating ethical considerations in the development of plans that utilize feedstocks intended for human nutrition and health. Thus, it is important to use bio-energy containing renewable resources in the most efficient way. This Concept goes beyond the synthesis of monomers and provides insights for establishing an industrial process that transforms renewable resources into high-value chemicals, and it describes careful investigations that are of paramount importance, including evaluations from an economical and an ecological perspective. The synthesis of monomers suitable for polymer production from renewable resources would ideally be accompanied by a reduction in CO2 emission and waste, through the complete molecular utilization of the feedstock. This Concept advocates the drop-in strategy, and is guided by the example of catalytically synthesized dimethyl 1,19-nonadecanedioate and its α,ω-functionalized derivatives. With respect to the Twelve Principles of Green Chemistry, this Concept describes a technological leap forward for a sustainable green chemical industry. PMID:25049162

  16. Development of selective catalytic oxidation (SCO) for NH{sub 3} and HCN removal from gasification gas; Selektiivisen katalyyttisen hapetusprosessin (SCO) kehittaeminen kaasutuskaasun NH{sub 3}:n ja HCN:n poistoon

    Energy Technology Data Exchange (ETDEWEB)

    Leppaelahti, J.; Koljonen, T.; Heiskanen, K. [VTT Energy, Espoo (Finland)

    1997-10-01

    In gasification, reactive nitrogen compounds (mainly NH{sub 3} and HCN) are formed from fuel nitrogen. If the gas containing NH{sub 3} is burned, a high NO{sub x} emission may be formed. The content of nitrogen compounds of the hot gasification gas could be reduced in Selective Catalytic Oxidation (SCO) process. In this process small amounts of reactive oxidisers are injected into the gas in order to convert NH{sub 3} to N{sub 2}. The utilization of SCO process together with low NO{sub x} burners in advanced gasification power stations might offer an alternative for flue gas treatment technologies like SCR (Selective Catalytic Reduction). In the earlier research, conditions were found, where oxidizers reacted selectively with ammonia in the gasification gas. Highest ammonia reduction took place in the aluminium oxide bed in the presence of NO and O{sub 2}. The aim of this study is to examine the reaction mechanism in order to be able to further evaluate the development possibilities of this kind process. The effect of composition and the amount of added oxidizer, the content of combustible gas components, space velocity, pressure and temperature will be studied. The experiments are carried out with the laboratory scale high pressure flow reactor of VTT Energy. Kinetic modelling of the experimental results is carried out in co-operation with the combustion chemistry group of Aabo Akademi. The aim of the modelling work is to bring insight to the gas-phase reactions that are important for the SCO-process. (orig.)

  17. Evaluation of Performance Catalytic Ozonation Process with Activated Carbon in the Removal of Humic Acids from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Gh. Asgari

    2011-01-01

    Full Text Available Introduction & Objective: In recent years, the use of alternative disinfectants and the control of natural organic matters are two approaches that are typically applied in water treatment utilities to reduce the formation of chlorinated disinfection by-products. Catalytic ozonation is a new technology used to promote the efficiency of ozonation. The goal of this study was to survey the feasibility application of activated carbon as a catalyst in ozonation process for removal of humic acids from aqueous solution. Materials & Methods: This experimental study has been done in laboratory of water and wastewater chemistry, Tarbiat Modarres University. The solid structure and chemical composition of activated carbon were analyzed by X-ray fluorescence (XRF. Ozonation and catalytic ozonation experiments were performed in a semi-batch reactor and the mass of ozone produced was measured by iodometric titration methods. Concentration changes of humic acid in samples with a concentration of 15 mg/l were determined by using spectrophotometer at an absorbance wavelength of 254 nm. To evaluate the performance of catalytic ozonation in humic acid removal, total organic carbon and trihalomethane formation potential were evaluated and the results were analyzed by Excel software. Results: Catalytic ozone results showed that using activated carbon as a catalyst increased humic acid decomposition up to 11 times and removal efficiency increased with increasing pH (4-12 and catalyst dosage (0.25-1.5 g/250cc. The experimental results showed that catalytic ozonation was most effective in less time (10 min with considerable efficiency (95% compared to the sole ozonation process (SOP. Conclusion: The results indicated that the catalytic ozonation process, compared to SOP, was less affected by radical scavenger, and total organic carbon, and trihalomethane formation potential removal achieved were 30% and 83%, respectively. (Sci J Hamadan Univ Med Sci 2011;17(4:25-33

  18. Gasification of empty fruit bunch for hydrogen rich fuel gas production

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed, M.A.A.; Salmiaton, A.; Wan Azlina, W.A.K.G.; Mohamad Amran, M.S. [University Putra Malaysia, Selangor (Malaysia). Dept. of Chemical and Environmental Engineering

    2011-07-01

    Dependence on fossil fuels as the main energy source has led to serious energy crisis and environmental problems. Therefore, due to the environmental considerations as well as the increasing demand for energy in the world, more attention has been paid to develop new energy sources. There has been interest in the utilization of biomass for production of environmental friendly biofuels. Biomass is a CO{sub 2} neutral resource in the lifecycle while CO{sub 2} is a primary contributor to the global greenhouse effect. Hence, increasing attention is being paid to biomass as a substitute for fossil fuel to reduce the global greenhouse effect, particularly under the commitment of the Kyoto Protocol. Biomass used as an energy resource can be efficiently achieved by thermo-chemical conversion technology: pyrolysis, gasification or combustion. Gasification process is one of the most promising thermo-chemical conversion routes to recover energy from biomass. A study on gasification of Empty Fruit Bunch (EFB), a waste of the palm oil industry is investigated. The composition and particle size distribution of feedstock are determined and the thermal degradation behavior is analyzed by a thermogravimetric analysis (TGA). Then 300 g h{sup -1} fluidized bed bench scale gasification unit is used to investigate the effect of the operating parameters on biomass gasification namely reactor temperature in the range of 700--1000 C and feedstock particle size in the range of 0.3--1.0 mm. The main gas species generated, as identified by Gas Chromatography (GC), are H{sub 2} CO, CO{sub 2} and CH{sub 4}. With temperature increasing from 700 to 1000 C, the total gas yield is enhanced greatly and has reached the maximum value ({approx}92 wt. %, on the raw biomass sample basis) at 1000 C with big portions of H{sub 2} (38.02 vol.%) and CO (36.36 vol.%). Feedstock particle size shows some influence on the H{sub 2}, CO and CH{sub 4} yields. The feedstock particle size of 0.3 to 0.5 mm is found to

  19. Measurement of very neutron-rich r-process nuclei with the BELEN setup

    International Nuclear Information System (INIS)

    Full text: Very neutron-rich nuclei can emit neutrons after β--decay when their reaction Q-value is larger than the (one/two/three) neutron separation energy. This decay mode is called -delayed (one/two/three)-neutron emission and was discovered in 1939 by Roberts et al. [1], shortly after the discoveries of fission by Meitner, Hahn, and Strassmann in 1938, and the neutron by Chadwick in 1932. Delayed in this context means, that the neutron is emitted with the -decay half-life of the precursor AZ, ranging from few milliseconds for the most neutron-rich isotopes up to 55.65 s for the (up to now) longest-lived βn-precursor 87Br. These delayed neutrons have to be distinguished from the prompt neutrons evaporated immediately (in the order of 10-14 s) after a fission event from a neutron-rich nucleus. βn measurements are commonly carried out since many decades, especially for fission fragments. With present and future nuclear physics facilities more and more neutron-rich isotopes outside the fission region become accessible which can also emit multiple neutrons. This exotic decay mode is of special interest for the astrophysical rapid neutron capture process (r process) since it leads to a deviation of the reaction flow to lower mass chains during the freeze-out phase. The exact knowledge of the beta-delayed neutron emission probability (Pn) is required to interpret the observed solar abundance peaks and draw conclusions from this about the participating r-process progenitor isotopes and their contributions. The BELEN (BEta-deLayEd Neutron) detector with its state-of-the-art digital electronics is one of the most powerful setups for the measurement of β-delayed neutrons in the world. Its present version consists of 48 3He-filled long counters and achieves - depending on the design - a neutron detection efficiency of up to 60%. This high efficiency is necessary for the detection of very neutron-rich n-emitters as well as for the detection of multiple neutronemitters

  20. Does residence time affect responses of alien species richness to environmental and spatial processes?

    Directory of Open Access Journals (Sweden)

    Matteo Dainese

    2012-08-01

    Full Text Available One of the most robust emerging generalisations in invasion biology is that the probability of invasion increases with the time since introduction (residence time. We analysed the spatial distribution of alien vascular plant species in a region of north-eastern Italy to understand the influence of residence time on patterns of alien species richness. Neophytes were grouped according to three periods of arrival in the study region (1500–1800, 1800–1900, and > 1900. We applied multiple regression (spatial and non-spatial with hierarchical partitioning to determine the influence of climate and human pressure on species richness within the groups. We also applied variation partitioning to evaluate the relative importance of environmental and spatial processes. Temperature mainly influenced groups with speciesa longer residence time, while human pressure influenced the more recently introduced species, although its influence remained significant in all groups. Partial regression analyses showed that most of the variation explained by the models is attributable to spatially structured environmental variation, while environment and space had small independent effects. However, effects independent of environment decreased, and spatially independent effects increased, from older to the more recent neophytes. Our data illustrate that the distribution of alien species richness for species that arrived recently is related to propagule pressure, availability of novel niches created by human activity, and neutral-based (dispersal limitation processes, while climate filtering plays a key role in the distribution of species that arrived earlier. This study highlights the importance of residence time, spatial structure, and environmental conditions in the patterns of alien species richness and for a better understanding of its geographical variation.

  1. Nine-Lump Kinetic Study of Catalytic Pyrolysis of Gas Oils Derived from Canadian Synthetic Crude Oil

    Directory of Open Access Journals (Sweden)

    Rui Zhang

    2016-01-01

    Full Text Available Catalytic pyrolysis of gas oils derived from Canadian synthetic crude oil on a kind of zeolite catalyst was conducted in a confined fluidized bed reactor for the production of light olefins. The overall reactants and products were classified into nine species, and a nine-lump kinetic model was proposed to describe the reactions based on appropriate assumptions. This kinetic model had 24 rate constants and a catalyst deactivation constant. The kinetic constants at 620°C, 640°C, 660°C, and 680°C were estimated by means of nonlinear least-square regression method. Preexponential factors and apparent activation energies were then calculated according to the Arrhenius equation. The apparent activation energies of the three feed lumps were lower than those of the intermediate product lumps. The nine-lump kinetic model showed good calculation precision and the calculated yields were close to the experimental ones.

  2. Evolution behavior of catalytically activated replication—decline in a coagulation process

    International Nuclear Information System (INIS)

    We propose a catalytically activated replication—decline model of three species, in which two aggregates of the same species can coagulate themselves, an A aggregate of any size can replicate itself with the help of B aggregates, and the decline of A aggregate occurs under the catalysis of C aggregates. By means of mean-field rate equations, we derive the asymptotic solutions of the aggregate size distribution ak (t) of species A, which is found to depend strongly on the competition among three mechanisms: the self-coagulation of species A, the replication of species A catalyzed by species B, and the decline of species A catalyzed by species C. When the self-coagulation of species A dominates the system, the aggregate size distribution ak(t) satisfies the conventional scaling form. When the catalyzed replication process dominates the system, ak(t) takes the generalized scaling form. When the catalyzed decline process dominates the system, ak(t) approaches the modified scaling form. (condensed matter: structural, mechanical, and thermal properties)

  3. From waste to energy -- Catalytic steam gasification of broiler litter

    Energy Technology Data Exchange (ETDEWEB)

    Jones, J.A.; Sheth, A.C.

    1999-07-01

    In 1996, the production of broiler chickens in the US was approximately 7.60 billion head. The quantity of litter generated is enormous. In 1992, the Southeast region alone produced over five million tons of broiler litter. The litter removed from the broiler houses is rich in nutrients and often spread over land as a fertilizer. Without careful management, the associated agricultural runoff can cause severe environmental damage. With increasing broiler litter production, the implementation of alternative disposal technologies is essential to the sustainable development of the poultry industry. A process originally developed for the conversion of coals to clean gaseous fuel may provide an answer. Catalytic steam gasification utilities an alkali salt catalyst and steam to convert a carbonaceous feedstock to a gas mixture composed primarily of carbon monoxide, carbon dioxide, hydrogen, and methane. The low to medium energy content gas produced may be utilized as an energy source or chemical feedstock. Broiler litter is an attractive candidate for catalytic steam gasification due to its high potassium content. Experiments conducted in UTSI's bench-scale high-pressure fixed bed gasifier have provided data for technical and economic feasibility studies of the process. Experiments have also been performed to examine the effects of temperature, pressure, and additional catalysts on the gasification rate.

  4. Gas burst vs. gas-rich magma recharge: A multidisciplinary study to reveal factors controlling triggering of the recent paroxysmal eruptions at Mt. Etna

    Science.gov (United States)

    Viccaro, Marco; Garozzo, Ileana; Cannata, Andrea; Di Grazia, Giuseppe; Gresta, Stefano

    2014-05-01

    the NSEC on the basis of the concordant or discordant behavior of anorthite and iron in plagioclase coupled with disequilibrium textures at the rim. Concordant anorthite and iron increases in plagioclase crystals with sieve-textured rims indicate recharge by more mafic, gas-rich magma. This textural-compositional behavior has been related to long-lasting eruptions, whose volcanic tremor amplitude evolution produced ramp-shaped increase of the volcanic tremor amplitude before the paroxysmal phase. On the contrary, crystals with sieve-textures at the rim, characterized by increasing iron at rather constant or decreasing anorthite, suggest the prominent role of gas injections into the residing system. In this instance, the compositional behavior has been linked with short-lasting eruptions, whose volcanic tremor amplitude evolution led to a sudden increase of the seismic amplitude before the climax of the eruption. Thus, our work put forward the idea that the evolution and duration of the Strombolian phase preceding the paroxysmal eruptions of 2011-2012 at Mt. Etna are strongly controlled by the eruption triggering mechanism, which can be either gas burst or gas-rich magma recharge.

  5. Gas purification facilities at Purex: Process study

    Energy Technology Data Exchange (ETDEWEB)

    Michels, L.R.; Gerhart, J.M.

    1958-12-31

    This report provides a summary of the results of a process study, requested by the Atomic Energy Commission an the recovery of krypton and xenon from irradiated uranium at the Hanford Purex Plant. This request was prompted by original Commission forecasts of the expanded requirements for Krypton-85 for commercial phosphorescent signal lights and markers and for xenon isotopes of low neutron cross-section for use in liquid xenon scintillation counters, in connection with D.M.A., government and university-sponsored work. It was requested that both Hanford and Savannah River submit order of magnitude cost estimates for recovery facilities at the respective sites for three separate design cases. The cost information developed, along with market survey information obtained-through the A. D. Little Company and Department of Defense market surveys, would serve as the basis for scheduling of the Hanford and Savannah River participation in the Commission`s overall fission rare gas recovery program.

  6. 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

  7. Richness and species composition of ants in the recovery process of a gully erosion

    Directory of Open Access Journals (Sweden)

    Gabriel Biagiotti

    2013-12-01

    Full Text Available This study aimed to determine how the richness and composition of ant species behaves with changes in the recovery process of a gully erosion. The study area has 0.9 hectares subdivided into three sections called sector: "A", "B" and "C". For the definition of the sectors, erosive and natural restoring were taken as the base level of activity. Four transects were laid systematically throughout the area and surrounding compound with forest and grassland. Each transect had three "pitfall trap" ten meters apart from each other, with catches of ants were held in rainy and dry seasons. Analysis of variance was applied to compare the number of ant species per plot captured and Scott-Knott test 5% for comparison of means. To verify the similarity of species between environments it was performed an analysis of similarity (ANOSIM and ordering of environments a "Nonmetric Multidimensional Scaling" (NMDS. We captured 74 species of ants inside and around the gully erosion. The more degraded environment and initial stage of regeneration, showed greater richness of ant species. The composition of ant species was different between the recovery environments and around. The parameters of ant communities analyzed, richness and composition species were influenced by the regeneration of the area, indicating that ants can be used as bioindicators of gullies recovery.

  8. Development of the Ni/Al{sub 2}O{sub 3}/ZrO{sub 2} catalyst to steam reforming of the natural gas process; Desenvolvimento do catalisador Ni/Al2O3/ZrO2 para o processo de reforma do gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Neiva, Laedna Souto; Ramalho, Melanea A.F.; Costa, Ana Cristina Figueiredo de Melo; Gama, Lucianna [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Andrade, Heloysa M.C. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil); Kiminami, Ruth Herta G.A. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil)

    2008-07-01

    The aim of this work is to develop catalyst of the type Ni/{alpha}-Al{sub 2}O{sub 3} modified with 0.005 mol of ZrO{sub 2} and structural, morphologic and catalytic characterizations, aiming employ in the reforming process of the natural gas. The catalytic supports were obtained by synthesis method for combustion reaction according to the concepts of the propellants chemistry. The active species of the catalyst (nickel) was deposited over the support by humid impregnation method. The catalytic supports were characterized by XRD, morphologic analysis by SEM and TEM, textural analysis by BET method before and after of the impregnation with nickel and were done catalytic tests in laboratory. The catalytic supports shows structure without any secondary phase with crystallinity elevated degree and crystal size varying between 5.7 and 7.0 nm. The catalytic test shows that these catalysts promoted a conversion percentile considerable of the natural gas in syngas. (author)

  9. Geochemical processes between steel projectiles and silica-rich targets in hypervelocity impact experiments

    Science.gov (United States)

    Ebert, Matthias; Hecht, Lutz; Deutsch, Alexander; Kenkmann, Thomas; Wirth, Richard; Berndt, Jasper

    2014-05-01

    The possibility of fractionation processes between projectile and target matter is critical with regard to the classification of the impactor type from geochemical analysis of impactites from natural craters. Here we present results of five hypervelocity MEMIN impact experiments (Poelchau et al., 2013) using the Cr-V-Co-Mo-W-rich steel D290-1 as projectile and two different silica-rich lithologies (Seeberger sandstone and Taunus quartzite) as target materials. Our study is focused on geochemical target-projectile interaction occurring in highly shocked and projectile-rich ejecta fragments. In all of the investigated impact experiments, whether sandstone or quartzite targets, the ejecta fragments show (i) shock-metamorphic features e.g., planar-deformation features (PDF) and the formation of silica glasses, (ii) partially melting of projectile and target, and (iii) significant mechanical and chemical mixing of the target rock with projectile material. The silica-rich target melts are strongly enriched in the "projectile tracer elements" Cr, V, and Fe, but have just minor enrichments of Co, W, and Mo. Inter-element ratios of these tracer elements within the contaminated target melts differ strongly from the original ratios in the steel. The fractionation results from differences in the reactivity of the respective elements with oxygen during interaction of the metal melt with silicate melt. Our results indicate that the principles of projectile-target interaction and associated fractionation do not depend on impact energies (at least for the selected experimental conditions) and water-saturation of the target. Partitioning of projectile tracer elements into the silicate target melt is much more enhanced in experiments with a non-porous quartzite target compared with the porous sandstone target. This is mainly the result of higher impact pressures, consequently higher temperatures and longer reaction times at high temperatures in the experiments with quartzite as

  10. Gas Sloshing in the Rich Cluster A2204: Putting Constraints on the Properties of the Magnetized Hot Plasma

    Science.gov (United States)

    Jones, Christine; Chen, Huanqing; Li, Zhiyuan; Andrade-Santos, Felipe; Zuhone, John

    2016-01-01

    We present results from our detailed analysis of the gas sloshing structures in the rich galaxy cluster Abell 2204, based on deep Chandra observations. We investigate the spiral structure in the X-ray surface brightness, which is a common signature of gas sloshing caused by an interaction with another nearby cluster. We identify discontinuities (edges) in the cluster surface brightness profiles in different directions from the cluster center. We measure the gas temperature, pressure and entropy across these surface brightness edges and find that the prominant surface brightness edges in the east and west are both typical "cold fronts", likely produced by gas sloshing. We use the results of our analysis to constrain the strength of the magnetic field in the cluster. We also use our measurements to provide an upper limit on the velocity of the cold gas beneath the front surface of the cold front. Finally we identify two subcluster candidates in the cluster outskirts, which may have been responsible for the gas sloshing.This research was supported by the Smithsonian Institution, Chandra Prime Contract NAS8-03060, Nanjing University, and the Massachusetts Institute for Technology.

  11. Novel Catalytic Reactor for CO2 Reduction via Sabatier Process Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Precision Combustion, Inc. (PCI) proposes to develop a novel, efficient, and lightweight catalytic Sabatier CO2 methanation unit, capable of converting a mixture of...

  12. Novel, Regenerable Microlith Catalytic Reactor for CO2 Reduction via Bosch Process Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Precision Combustion, Inc. (PCI) proposes to develop an extremely compact, lightweight and regenerable MicrolithREG catalytic CO2 reduction reactor, capable of...

  13. A process optimization for bio-catalytic production of substituted catechols (3-nitrocatechol and 3-methylcatechol

    Directory of Open Access Journals (Sweden)

    Tiwary Bhupendra N

    2010-06-01

    Full Text Available Abstract Background Substituted catechols are important precursors for large-scale synthesis of pharmaceuticals and other industrial products. Most of the reported chemical synthesis methods are expensive and insufficient at industrial level. However, biological processes for production of substituted catechols could be highly selective and suitable for industrial purposes. Results We have optimized a process for bio-catalytic production of 3-substituted catechols viz. 3-nitrocatechol (3-NC and 3-methylcatechol (3-MC at pilot scale. Amongst the screened strains, two strains viz. Pseudomonas putida strain (F1 and recombinant Escherichia coli expression clone (pDTG602 harboring first two genes of toluene degradation pathway were found to accumulate 3-NC and 3-MC respectively. Various parameters such as amount of nutrients, pH, temperature, substrate concentration, aeration, inoculums size, culture volume, toxicity of substrate and product, down stream extraction, single step and two-step biotransformation were optimized at laboratory scale to obtain high yields of 3-substituted catechols. Subsequently, pilot scale studies were performed in 2.5 liter bioreactor. The rate of product accumulation at pilot scale significantly increased up to ~90-95% with time and high yields of 3-NC (10 mM and 3-MC (12 mM were obtained. Conclusion The biocatalytic production of 3-substituted catechols viz. 3-NC and 3-MC depend on some crucial parameters to obtain maximum yields of the product at pilot scale. The process optimized for production of 3-substituted catechols by using the organisms P. putida (F1 and recombinant E. coli expression clone (pDTG602 may be useful for industrial application.

  14. Large pilot plant alternatives for scaleup of the catalytic coal gasification process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, S.J.

    1979-01-01

    This is the final report for US Department of Energy Contract No. EX-76-C-01-2480, Scaleup Requirements of the Exxon Catalyzed Coal Gasification Process. The objective was to develop the information necessary to determine if an existing DOE large pilot plant could be used to obtain the scaleup data necessary to design and construct a Catalytic Coal Gasification (CCG) pioneer plant with acceptable risk. A pioneer plant is a stand-alone facility, whose primary function is to operate as a profitable commercial venture. The pioneer plant would contain all equipment of full commercial size, as defined by the requirements for an optimum-sized commercial plant. However, the pioneer plant could have a single train of equipment in some or all of the plant sections. The three tasks contained in this contract are discussed: study design and cost estimate for a grass-roots large pilot plant; selection of the preferred existing pilot plant; and study design and cost estimate for revamp of the preferred existing pilot plant.

  15. Cytochrome c oxidase loses catalytic activity and structural integrity during the aging process in Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Jian-Ching; Rebrin, Igor [Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90033 (United States); Klichko, Vladimir; Orr, William C. [Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275 (United States); Sohal, Rajindar S., E-mail: sohal@usc.edu [Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90033 (United States)

    2010-10-08

    Research highlights: {yields} Cytochrome c oxidase loses catalytic activity during the aging process. {yields} Abundance of seven nuclear-encoded subunits of cytochrome c oxidase decreased with age in Drosophila. {yields} Cytochrome c oxidase is specific intra-mitochondrial site of age-related deterioration. -- Abstract: The hypothesis, that structural deterioration of cytochrome c oxidase (CcO) is a causal factor in the age-related decline in mitochondrial respiratory activity and an increase in H{sub 2}O{sub 2} generation, was tested in Drosophila melanogaster. CcO activity and the levels of seven different nuclear DNA-encoded CcO subunits were determined at three different stages of adult life, namely, young-, middle-, and old-age. CcO activity declined progressively with age by 33%. Western blot analysis, using antibodies specific to Drosophila CcO subunits IV, Va, Vb, VIb, VIc, VIIc, and VIII, indicated that the abundance these polypeptides decreased, ranging from 11% to 40%, during aging. These and previous results suggest that CcO is a specific intra-mitochondrial site of age-related deterioration, which may have a broad impact on mitochondrial physiology.

  16. Cytochrome c oxidase loses catalytic activity and structural integrity during the aging process in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Research highlights: → Cytochrome c oxidase loses catalytic activity during the aging process. → Abundance of seven nuclear-encoded subunits of cytochrome c oxidase decreased with age in Drosophila. → Cytochrome c oxidase is specific intra-mitochondrial site of age-related deterioration. -- Abstract: The hypothesis, that structural deterioration of cytochrome c oxidase (CcO) is a causal factor in the age-related decline in mitochondrial respiratory activity and an increase in H2O2 generation, was tested in Drosophila melanogaster. CcO activity and the levels of seven different nuclear DNA-encoded CcO subunits were determined at three different stages of adult life, namely, young-, middle-, and old-age. CcO activity declined progressively with age by 33%. Western blot analysis, using antibodies specific to Drosophila CcO subunits IV, Va, Vb, VIb, VIc, VIIc, and VIII, indicated that the abundance these polypeptides decreased, ranging from 11% to 40%, during aging. These and previous results suggest that CcO is a specific intra-mitochondrial site of age-related deterioration, which may have a broad impact on mitochondrial physiology.

  17. Development of a process for continuous, radiation-chemically initiated, catalytic hydrocarboxylation

    International Nuclear Information System (INIS)

    In the general part are treated technical preparation of aliphatic carboxylic acids and their economical importance, the hydrocarboxylation reaction and general aspects of radiation chemistry. The chapter on results of discontinuous experiments contains experiments of radiochemically initiated catalytical hydroesterification of oct-1-ene and buteneoxide. The chapter on development and arrangement of the continuously working hydrocarboxylation plant deals with the disposition of process flow sheet, single elements of and description of the plant. The chapter on results of continuous experiments describes residence time behaviour of the tube reactor, investigations on the mixing behaviour of educts, influence of residence time and reaction pressure on continuous thermal and thermal-radiochemical hydrocarboxylation. The next chapter proposes a procedure of continuous hydrobarboxylation and esterification at high pressure on an industrial scale. The experimental part presents starting materials, preparation on catalysts and reference substances, performance of discontinuous autoclave experiments, work up and investigation of reaction products, performance of continuous high pressure experiments, Co-60-source, Fricke-dosimetry and analytics. (SPI)

  18. Catalytic synthesis of bamboo-like multiwall BN nanotubes via SHS-annealing process

    International Nuclear Information System (INIS)

    Bamboo-like multiwall boron nitride (BN) nanotubes were synthesized via annealing porous precursor prepared by self-propagation high temperature synthesis (SHS) method. The as-synthesized BN nanotubes were characterized by the field emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), high-resolution TEM (HRTEM), X-ray diffraction (XRD), Raman and Fourier transform infrared (FTIR) spectroscopy. These nanotubes have uniform diameters of about 60 nm and an average length of about 10 μm. Four growth models, including tip, base, based tip and base-tip growth models, are proposed based on the catalytic vapor-liquid-solid (VLS) growth mechanism for explaining the formation of the as-synthesized bamboo-like BN nanotubes. Chemical reactions and annealing mechanism are also discussed. -- Graphical Abstract: A novel and effective annealing porous precursor route to bulk synthesis of bamboo-like multiwall BN nanotubes. Four growth models of VLS growth mechanism for these nanotubes are proposed. Display Omitted Research highlights: → Bulk bamboo-like BN nanotubes were synthesized by SHS-annealing method. → Boron-containing, porous precursor played a crucial role in bulk synthesis process. → Four possible growth models were proposed to explain the formation of the bamboo-like BN nanotubes.

  19. Catalytic hydrogen production from fossil fuels via the water gas shift reaction

    International Nuclear Information System (INIS)

    Highlights: • Hydrogen is a clean alternative to hydrocarbon fuels. • Hydrogen is primarily produced with the water gas shift reaction. • Development of water gas shift catalysts is essential to the energy industry. • This work summarizes recent progress in water gas shift catalyst research. - Abstract: The production of hydrogen is a highly researched topic for many reasons. First of all, it is a clean fuel that can be used instead of hydrocarbons, which produce CO2, a greenhouse gas emission that is thought to be the reason for climate change in the world. The largest source of hydrogen is the water gas shift (WGS) reaction, where CO and water are mixed over a catalyst to produce the desired hydrogen. Many researchers have focused on development of WGS catalysts with different metals. The most notable of these metals are precious and rare earth metals which, when combined, have unique properties for the WGS reaction. Research in this area is very important to the energy industry and the future of energy around the world. However, the progress made recently has not been reviewed, and this review was designed to fill the gap

  20. Catalytic ozonation not relying on hydroxyl radical oxidation: A selective and competitive reaction process related to metal-carboxylate complexes

    KAUST Repository

    Zhang, Tao

    2014-01-01

    Catalytic ozonation following non-hydroxyl radical pathway is an important technique not only to degrade refractory carboxylic-containing organic compounds/matter but also to avoid catalyst deactivation caused by metal-carboxylate complexation. It is unknown whether this process is effective for all carboxylates or selective to special molecule structures. In this work, the selectivity was confirmed using O3/(CuO/CeO2) and six distinct ozone-resistant probe carboxylates (i.e., acetate, citrate, malonate, oxalate, pyruvate and succinate). Among these probe compounds, pyruvate, oxalate, and citrate were readily degraded following the rate order of oxalate>citrate>pyruvate, while the degradation of acetate, malonate, and succinate was not promoted. The selectivity was independent on carboxylate group number of the probe compounds and solution pH. Competitive degradation was observed for carboxylate mixtures following the preference order of citrate, oxalate, and finally pyruvate. The competitive degradation was ascribed to competitive adsorption on the catalyst surface. It was revealed that the catalytically degradable compounds formed bidentate chelating or bridging complexes with surface copper sites of the catalyst, i.e., the active sites. The catalytically undegradable carboxylates formed monodentate complexes with surface copper sites or just electrostatically adsorbed on the catalyst surface. The selectivity, relying on the structure of surface metal-carboxylate complex, should be considered in the design of catalytic ozonation process. © 2013 Elsevier B.V.

  1. Simulation of Cobalt-Rich Crust's Crushing Process Based on ANSYS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    It is a great concern in international oceanology to mine cobalt-rich crust. At present, spiral mining head is regarded as the best crushing scheme. Based on the dynamic model of spiral mining head, the of cobalt crust's crushing process was simulated with the ANSYS software. The material model of Johnson and Cook Plasticity, maximal principal stress failure criterion, and eroding contact arithmetic were selected. At the same time, the influence of cutting depth, feed speed, rotational speed of mining head on torque and force subjected by mining head was taken into account. At last a computer simulation model of crushing process of cobalt crust was established. By analyzing simulation results, the relationships among these controllable process parameters, torque and force can be obtained, which will provide a technical reference for practical mining system.

  2. No effect of platelet-rich plasma with frozen or processed bone allograft around noncemented implants

    DEFF Research Database (Denmark)

    Jensen, T B; Rahbek, O; Overgaard, S; Søballe, Kjeld

    2005-01-01

    We compared processed morselized bone allograft with fresh-frozen bone graft around noncemented titanium implants. Also, the influence of platelet-rich plasma (PRP) in combination with bone allograft was evaluated. Analysis was based on implant fixation and histomorphometry. PRP was prepared by...... isolating the buffy coat from autologous blood samples. Bone allograft was used fresh-frozen or processed by defatting, freeze drying, and irradiation. Cylindrical hydroxyapatite-coated titanium implants were inserted bilaterally in the femoral condyles of eight dogs. Each implant was surrounded by a 2.5-mm...... bone allograft processing. Even though the level of platelet in PRP was 7.7 times that found in whole blood, we found no improvement of bone formation or implant fixation by adding PRP....

  3. Simulation of a Wet Sulfuric Acid Process (WSA for Utilization of Acid Gas Separated from Omani Natural Gas

    Directory of Open Access Journals (Sweden)

    Ahmed Jawad Ali Al-Dallal

    2013-06-01

    Full Text Available In this study, a proposed process for the utilization of hydrogen sulphide separated with other gases from omani natural gas for the production of sulphuric acid by wet sulphuric acid process (WSA was studied. The processwas simulated at an acid gas feed flow of 5000 m3/hr using Aspen ONE- V7.1-HYSYS software. A sensitivity analysis was conducted to determine the optimum conditions for the operation of plant. This included primarily the threepacked bed reactors connected in series for the production of sulphur trioxidewhich represented the bottleneck of the process. The optimum feed temperature and catalyst bed volume for each reactor were estimated and then used in the simulation of the whole process for two cases namely 4 and 6 mole% SO2 stream fed to the first catalytic reactor. The 4mole% SO2 gaves the highest conversion (98% compared with 6 mole% SO2 (94.7%. A valuable quantity of heat was generated from the process. This excess heat could also be transformed into power in a turbine or used as a heating media in neighbouring process units.

  4. Headspace gas chromatography-mass spectrometry of volatile compounds in murici (Byrsonima crassifolia l. Rich).

    Science.gov (United States)

    Alves, G L; Franco, M R B

    2003-01-24

    Northern and Northeastern Brazil have a natural diversity of fruits, many of which are considered exotic, presenting different flavors and aromas. The enormous diversity of fruits represents a promising area for research on aromas. There is also a great potential for the manufacture of juices, desserts or other processed products. Murici is a typical fruit from these regions presenting a different flavor, reminiscent of that of cheese. This fruit is consumed mainly as juice, ice cream or as liquor, greatly appreciated by the local population. Headspace volatile compounds of three lots of the fruit from Ceará (Fortaleza) were collected by suction on Porapak Q for 2 h and desorbed with 300 microl of acetone. The isolated volatile compounds were separated by high resolution GC. Forty-six volatile compounds were detected, of which 41 were identified by gas chromatography-mass spectrometry and Kovats indices. The most abundant compounds were ethanol (28.3%) and ethyl hexanoate (25.1%). Butanoic acid (5.1%), hexanoic acid (5.1%) and methyl butyrate (2.8%) were also detected in the headspace of the fruit and confirm its unusual cheese aroma. PMID:12580497

  5. Formation of Andromeda II via a gas-rich major merger and an interaction with M31

    CERN Document Server

    Fouquet, Sylvain; del Pino, Andres; Ebrova, Ivana

    2016-01-01

    Andromeda II (And II) has been known for a few decades but only recently observations have unveiled new properties of this dwarf spheroidal galaxy. The presence of two stellar populations, the bimodal star formation history (SFH) and an unusual rotation velocity of And II put strong constrains on its formation and evolution. Following Lokas et al. (2014), we propose a detailed model to explain the main properties of And II involving (1) a gas-rich major merger between two dwarf galaxies at high redshift in the field and (2) a close interaction with M31 about 5 Gyr ago. The model is based on N-body/hydrodynamical simulations including gas dynamics, star formation and feedback. One simulation is designed to reproduce the gas-rich major merger explaining the origin of stellar populations and the SFH. Other simulations are used to study the effects of tidal forces and the ram pressure stripping during the interaction between And II and M31. The model successfully reproduces the SFH of And II including the propert...

  6. Membrane separation processes for argon plasma gas recovery

    OpenAIRE

    Harlacher, Thomas

    2014-01-01

    A mixture of argon and hydrogen is used as plasma gas in a thermal plasma synthesis for the production of silicon carbide. Next to argon and hydrogen, the exhaust gas of the ceramic synthesis contains carbon monoxide. Since argon is an expensive gas, the plasma gas needs to be recycled. For this purpose, the carbon monoxide has to be removed from the exhaust gas. The applicability of a membrane based gas separation process for this separation task was investigated in this study. A process rou...

  7. Structural and catalytic properties of a novel vanadium containing solid core mesoporous silica shell catalysts for gas phase oxidation reaction

    Indian Academy of Sciences (India)

    N Venkatathri; Vijayamohanan K Pillai; A Rajini; M Nooka Raju; I A K Reddy

    2013-01-01

    A novel vanadium containing solid core mesoporous silica shell catalyst was synthesized with different Si/V ratios by sol-gel method under neutral conditions. The synthesized materials were characterized by various techniques and gas phase diphenyl methane oxidation reaction. The mesoporosity combined with microporosity are formed by incorporation of octadecyltrichloro silane and triethylamine in the catalyst and it was found out from E-DAX and BET—surface area analysis. The material was found to be nanocrystalline. Vanadium is present as V4+ species in as-synthesized samples and convert to V5+ on calcination. Most of the vanadium is present in tetrahedral or square pyramidal environment. Incorporation of vanadium in silica framework was confirmed by 29Si MAS NMR analysis. Among the various vanadium containing solid core mesoporous silica shell catalysts, the Si/V =100 ratio exhibited maximum efficiency towards diphenyl methane to benzophenone gas phase reaction. The optimum condition required for maximum conversion and selectivity was found out from the catalytic studies.

  8. Synthesis of high purity single-walled carbon nanotubes from ethanol by catalytic gas flow CVD reactions

    International Nuclear Information System (INIS)

    Highly pure single-walled carbon nanotubes (SWNTs) with their contents >96% of the total products were achieved by chemical vapour deposition gas flow reactions using ethanol as the carbon source. The high purity SWNTs were formed under critically controlled synthesis conditions and by applying a high hydrogen flow, under which the non-catalytic condensation of carbon was completely suppressed. Purification of the products in acid at ambient conditions readily yielded over 99% pure SWNT products, as the only impurities left in the products were iron particles of clean surface. Therefore, the present study demonstrates the full potential of the CVD gas flow reactions in continuous production of high quality SWNTs. Comparable syntheses were conducted using other alcohols in place of ethanol and it was found that high alkyl alcohols like isopropanol and hexanol produced more amorphous carbon while methanol produced no carbon. The high yield growth of SWNTs was attributed greatly to the reaction chemistry of ethanol and the 'right' amount of hydrogen in the system, as discussed

  9. Chemical and isotopic tracers of the contribution of microbial gas in Devonian organic-rich shales and reservoir sandstones, northern Appalachian Basin

    International Nuclear Information System (INIS)

    In this study, the geochemistry and origin of natural gas and formation waters in Devonian age organic-rich shales and reservoir sandstones across the northern Appalachian Basin margin (western New York, eastern Ohio, northwestern Pennsylvania, and eastern Kentucky) were investigated. Additional samples were collected from Mississippian Berea Sandstone, Silurian Medina Sandstone and Ordovician Trenton/Black River Group oil and gas wells for comparison. Dissolved gases in shallow groundwaters in Devonian organic-rich shales along Lake Erie contain detectable CH4 (0.01-50.55 mol%) with low δ13C-CH4 values (-74.68 to -57.86 per mille) and no higher chain hydrocarbons, characteristics typical of microbial gas. Nevertheless, these groundwaters have only moderate alkalinity (1.14-8.72 meq/kg) and relatively low δ13C values of dissolved inorganic C (DIC) (-24.8 to -0.6 per mille), suggesting that microbial methanogenesis is limited. The majority of natural gases in Devonian organic-rich shales and sandstones at depth (>168 m) in the northern Appalachian Basin have a low CH4 to ethane and propane ratios (3-35 mol%; C1/C2 + C3) and high δ13C and δD values of CH4 (-53.35 to -40.24 per mille, and -315.0 to -174.6 per mille, respectively), which increase in depth, reservoir age and thermal maturity; the molecular and isotopic signature of these gases show that CH4 was generated via thermogenic processes. Despite this, the geochemistry of co-produced brines shows evidence for microbial activity. High δ13C values of DIC (>+10 per mille), slightly elevated alkalinity (up to 12.01 meq/kg) and low SO4 values (13C-DIC values (4 concentrations (up to 12.31 mmole/L) in many brine samples point to SO4 reduction, which likely limits microbial CH4 generation in the Appalachian Basin. Together the formation water and gas results suggest that the vast majority of CH4 in the Devonian organic-rich shales and sandstones across the northern Appalachian Basin margin is thermogenic in

  10. Catalytic reduction of methane/unburned hydrocarbons in smoke from lean-burn gas engines

    International Nuclear Information System (INIS)

    The aim of this project has been: To describe the flue gas conditions of typical stationary gas engines for cogeneration; To evaluate the predominant causes of deactivation of oxidation catalysts under realistic operation conditions; To develop improved long-term stable oxidation catalysts; To evaluate alternative catalyst-based methane reduction technologies. Most gas engines for stationary purposes are efficient lean-burn gas engines. Both the high efficiency and the very lean operation lead to low exhaust temperatures. However, there is now a tendency to design engines with un-cooled exhaust manifolds. This leads to higher shaft efficiency and increases the exhaust temperature. Exhaust gas composition and temperatures during continuous operation and start/stops are given in this report. Analyses have been made of catalyst samples to find predominant causes for oxidation catalyst deactivation. The analyses have shown that the presence of sulphur dioxide in the flue gas causes sulphur poisoning on the active catalyst surface. This effect is dependent on both the catalyst formulation and the catalyst support material composition. Neither sintering, nor other poisoning components than sulphur have been on the examined catalyst samples. The sulphur dioxide in the exhaust is a result of the sulphur in the odorisation additive used in the natural gas (approx. 10 mg/n3 m THT) and of the sulphur present in combusted lubrication oil. These sources leads to a level of approx. 0.3 - 0.6 ppm (vol) SO2 in the exhaust gas. Based on a large number of laboratory tests, a new oxidation catalyst formulation has been developed and successfully tested over 5000 hours of operation at a commercial cogeneration plant. This long-term testing has been additionally supplemented by short-term testings at test sites to see performance under other operation conditions. It has been shown that a rise in flue gas temperature (from e.g. 450 deg. C) will significantly reduce the necessary

  11. Catalytic Process for the Conversion of Coal-derived Syngas to Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    James Spivery; Doug Harrison; John Earle; James Goodwin; David Bruce; Xunhau Mo; Walter Torres; Joe Allison Vis Viswanathan; Rick Sadok; Steve Overbury; Viviana Schwartz

    2011-07-29

    The catalytic conversion of coal-derived syngas to C{sub 2+} alcohols and oxygenates has attracted great attention due to their potential as chemical intermediates and fuel components. This is particularly true of ethanol, which can serve as a transportation fuel blending agent, as well as a hydrogen carrier. A thermodynamic analysis of CO hydrogenation to ethanol that does not allow for byproducts such as methane or methanol shows that the reaction: 2 CO + 4 H{sub 2} {yields} C{sub 2}H{sub 5}OH + H{sub 2}O is thermodynamically favorable at conditions of practical interest (e.g,30 bar, {approx}< 250 C). However, when methane is included in the equilibrium analysis, no ethanol is formed at any conditions even approximating those that would be industrially practical. This means that undesired products (primarily methane and/or CO{sub 2}) must be kinetically limited. This is the job of a catalyst. The mechanism of CO hydrogenation leading to ethanol is complex. The key step is the formation of the initial C-C bond. Catalysts that are selective for EtOH can be divided into four classes: (a) Rh-based catalysts, (b) promoted Cu catalysts, (c) modified Fischer-Tropsch catalysts, or (d) Mo-sulfides and phosphides. This project focuses on Rh- and Cu-based catalysts. The logic was that (a) Rh-based catalysts are clearly the most selective for EtOH (but these catalysts can be costly), and (b) Cu-based catalysts appear to be the most selective of the non-Rh catalysts (and are less costly). In addition, Pd-based catalysts were studied since Pd is known for catalyzing CO hydrogenation to produce methanol, similar to copper. Approach. The overall approach of this project was based on (a) computational catalysis to identify optimum surfaces for the selective conversion of syngas to ethanol; (b) synthesis of surfaces approaching these ideal atomic structures, (c) specialized characterization to determine the extent to which the actual catalyst has these structures, and (d) testing

  12. Carbon dioxide removal in gas treating processes

    Energy Technology Data Exchange (ETDEWEB)

    Lidal, H.

    1992-06-01

    The main contribution of this work is the development of a simple and reliable modelling technique on carbon dioxide removal describing the vapor-liquid equilibria of CO{sub 2} in aqueous alkanolamine solutions. By making use of measured pH data, the author has circumvented the problem of estimating interaction parameters, activity coefficients, and equilibrium constants in the prediction of vapor-liquid equilibria. The applicability of the model is best demonstrated on the tertiary amine system using MDEA. For this system, the VLE is accurately represented for temperatures in the range 25 to 140{sup o}C, for CO{sub 2} loadings from 0.001 to 1 mol/mol, and for amine molarities usually encountered in acid gas treating processes. The absorption of CO{sub 2} into solutions containing the sterically hindered amine AMP, is also well described by the model. The equilibrium of CO{sub 2} in mixed solvents containing a glycol (TEG,DEG) and an alkonolamine (MEA,DEA) has been measured at temperatures encountered in the absorption units. An equilibrium model has been developed for the CO{sub 2}/TEG/MEA system for estimation of CO{sub 2} partial pressures, covering loadings and temperatures for both absorption and desorption conditions. An important spin-off of the work described is that two new experimental set-ups have been designed and built. 154 refs., 38 figs., 22 tabs.

  13. Carbon dioxide removal in gas treating processes

    International Nuclear Information System (INIS)

    The main contribution of this work is the development of a simple and reliable modelling technique on carbon dioxide removal describing the vapor-liquid equilibria of CO2 in aqueous alkanolamine solutions. By making use of measured pH data, the author has circumvented the problem of estimating interaction parameters, activity coefficients, and equilibrium constants in the prediction of vapor-liquid equilibria. The applicability of the model is best demonstrated on the tertiary amine system using MDEA. For this system, the VLE is accurately represented for temperatures in the range 25 to 140oC, for CO2 loadings from 0.001 to 1 mol/mol, and for amine molarities usually encountered in acid gas treating processes. The absorption of CO2 into solutions containing the sterically hindered amine AMP, is also well described by the model. The equilibrium of CO2 in mixed solvents containing a glycol (TEG,DEG) and an alkonolamine (MEA,DEA) has been measured at temperatures encountered in the absorption units. An equilibrium model has been developed for the CO2/TEG/MEA system for estimation of CO2 partial pressures, covering loadings and temperatures for both absorption and desorption conditions. An important spin-off of the work described is that two new experimental set-ups have been designed and built. 154 refs., 38 figs., 22 tabs

  14. Catalytic conversion of biomass-derived synthesis gas to liquid fuels

    OpenAIRE

    Suárez París, Rodrigo

    2016-01-01

    Climate change is one of the biggest global threats of the 21st century. Fossil fuels constitute by far the most important energy source for transportation and the different governments are starting to take action to promote the use of cleaner fuels. Biomass-derived fuels are a promising alternative for diversifying fuel sources, reducing fossil fuel dependency and abating greenhouse gas emissions. The research interest has quickly shifted from first-generation biofuels, obtained from food co...

  15. Carbon to electricity in a solid oxide fuel cell combined with an internal catalytic gasification process

    Institute of Scientific and Technical Information of China (English)

    M. Konsolakis; G. E. Marnellos; A. Al-Musa; N. Kaklidis; I. Garagounis; V. Kyriakou

    2015-01-01

    This study explores strategies to develop highly efficient direct carbon fuel cells (DCFCs) by com‐bining a solid‐oxide fuel cell (SOFC) with a catalyst‐aided carbon‐gasification process. This system employs Cu/CeO2 composites as both anodic electrodes and carbon additives in a cell of the type:carbon|Cu‐CeO2/YSZ/Ag|air. The study investigates the impact on in situ carbon‐gasification and DCFC performance characteristics of catalyst addition and variation in the carrier gas used (inert He versus reactive CO2). The results indicate that cell performance is significantly improved by infusing the catalyst into the carbon feedstock and by employing CO2 as the carrier gas. At 800 °C, the maxi‐mum power output is enhanced by approximately 40% and 230% for carbon/CO2 and car‐bon/catalyst/CO2 systems, respectively, compared with that of the carbon/He configuration. The increase observed when employing the catalyst and CO2 as the carrier gas can be primarily at‐tributed to the pronounced effect of the catalyst on carbon‐gasification through the re‐verse‐Boudouard reaction, and the subsequent in situ electro‐oxidation of CO at the anode three‐phase boundary.

  16. Catalytic upgrading of gas from biofuels and implementation of electricity production

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P.; Hepola, J.; Heiskanen, K. [VTT Energy, Espoo (Finland)

    1997-10-01

    Kinetic modelling of tar model compound (benzene) reaction with CO{sub 2} over dolomite (Kalkkimaa dolomite) catalyst has been carried out. This modelling has been based mainly on results obtained in earlier project. However, some additional tests have been made to complete the data. The data obtained was fitted to four different Langmuir-Hinshelwood type of kinetic rate equations in order to find the best suited model for the reaction. The model that best described the data assumed single site benzene adsorption and non-dissociative CO{sub 2} adsorption. Kinetical modelling work was continued by studies considering steam reforming of tar. Reaction rates were measured with large excess of water to benzene then with stoichiometric ratio of water to benzene and in simulated gasification gas. Conditions free of external (film) and internal (pore) diffusion effects were used. Reactor was operated both in differential and integral modes. Preliminary modelling was carried out and kinetical parameters for simple first order reaction model were calculated. During the first half of the year complementary experiments concerning earlier studies on sulfur poisoning of nickel catalysts were carried out. The experiments were performed in fixed bed tube reactors and in a TPH-reactor of VTT. In addition, several analytical methods for determining the nature of adsorbed sulfur on the catalyst surface was used. During the other part of the year two complementary report drafts concerning sulfur poisoning of nickel catalysts at hot gas cleaning conditions of gasification gas were prepared. (orig.)

  17. The fate of massive black holes in gas-rich galaxy mergers

    Directory of Open Access Journals (Sweden)

    A. Escala

    2006-01-01

    Full Text Available Utilizando simulaciones num ericas SPH, investigamos los efectos de gas sobre la inspiral y la fusi on de una binaria de agujeros negros masivos. Este estudio fue motivado por los discos de gas nucleares muy masivos que se observan en las regiones centrales de galaxias en fusi on. Aqu presentamos los resultados que ampl an el tratamiento de trabajos previos (Escala et al. 2004, 2005 mediante el estudio de la evoluci on de una binaria con diferentes masas de agujeros negros en un disco de gas masivo.

  18. Upgrading of bio-oil to boiler fuel by catalytic hydrotreatment and esterification in an efficient process

    International Nuclear Information System (INIS)

    Bio-oil can't be directly used as fuel due to its deteriorate properties. Here, an efficient catalytic upgrading process for the bio-oil, including esterification, hydrogenation, hydrodeoxygenation and depolymerization, is proposed with multifunctional catalyst Ni/SiO2–ZrO2 and biomass-derived solvent ethanol. Results showed that esters, alcohols, phenolics, and cyclo-ketones were the main components in the upgraded bio-oil while aldehydes were removed completely via catalytic hydrogenation and acids were removed by catalytic esterification with supercritical ethanol. The pH value of upgraded bio-oil rose drastically from 2.38 to 5.24, and the high heating value increased to 24.4 MJ kg−1. Comparison characterization on the upgraded and crude bio-oil using FT-IR, GPC (Gel permeation chromatography) and 13C NMR (Nuclear Magnetic Resonance) demonstrated that lignin-derived oligomers contained in crude bio-oil were further depolymerized over Ni/SiO2–ZrO2 catalyst. The improved properties suggest that the upgraded bio-oil is more suitable to be used as boiler fuel. Furthermore, the loss of carbon is negligible because formation of coke is suppressed during the upgrading process. - Highlights: • Acid can be converted via catalytic esterification in supercritical ethanol. • Aldehydes can be removed completely during the upgrading process. • Lignin-derived oligomers were further depolymerized during the upgrading process. • Formation of coke is effectively inhibited during the upgrading process

  19. Non-catalytic alcoholysis process for production of biodiesel fuel by using bubble column reactor

    Science.gov (United States)

    Hagiwara, S.; Nabetani, H.; Nakajima, M.

    2015-04-01

    -edible lipids by use of the SMV reactor has not been examined yet. Therefore, this study aims to investigate the productivity of biodiesel produced from waste vegetable oils using the SMV reactor. Biodiesel fuel is a replacement for diesel as a fuel produced from biomass resources. It is generally produced as a FAME derived from vegetable oil by using alkaline catalyzed alcoholysis process. This alkaline method requires deacidification process prior to the reaction process and the alkaline catalyst removal process after the reaction. Those process increases the total cost of biodiesel fuel production. In order to solve the problems in the conventional alkaline catalyzed alcoholysis process, the authors proposed a non-catalytic alcoholysis process called the Superheated Methanol Vapor (SMV) method with bubble column reactor. So, this study aims to investigate the productivity of biodiesel produced from vegetable oils and other lipids using the SMV method with bubble column reactor.

  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. Conventional processes and membrane technology for carbon dioxide removal from natural gas: A review

    Institute of Scientific and Technical Information of China (English)

    Zee Ying Yeo; Thiam Leng Chew; Peng Wei Zhu; Abdul Rahman Mohamed; Siang-Piao Chai

    2012-01-01

    Membrane technology is becoming more important for CO2 separation from natural gas in the new era due to its process simplicity,relative ease of operation and control,compact,and easy to scale up as compared with conventional processes.Conventional processes such as absorption and adsorption for CO2 separation from natural gas are generally more energy demanding and costly for both operation and maintenance.Polymeric membranes are the current commercial membranes used for CO2 separation from natural gas.However,polymeric membranes possess drawbacks such as low permeability and selectivity,plasticization at high temperatures,as well as insufficient thermal and chemical stability.The shortcomings of commercial polymeric membranes have motivated researchers to opt for other alternatives,especially inorganic membranes due to their higher thermal stability,good chemical resistance to solvents,high mechanical strength and long lifetime.Surface modifications can be utilized in inorganic membranes to further enhance the selectivity,permeability or catalytic activities of the membrane.This paper is to provide a comprehensive review on gas separation,comparing membrane technology with other conventional methods of recovering CO2 from natural gas,challenges of current commercial polymeric membranes and inorganic membranes for CO2 removal and membrane surface modification for improved selectivity.

  2. Gas benefits from Middle East peace processes

    International Nuclear Information System (INIS)

    The prospects for building a pipeline to bring Egyptian gas to Israel are described. Topics covered include the level of gas reserves, potential markets in Israel and Palestine and financial backers for the pipeline project. The investment risk associated with the project is discussed. (UK)

  3. Advanced treatment of oilfield production wastewater by an integration of coagulation/flotation, catalytic ozonation and biological processes.

    Science.gov (United States)

    Chen, Ke-Yong; Zhang, Xiao-Bing; Li, Jun

    2016-10-01

    In this study, advanced treatment of heavily polluted oilfield production wastewater (OPW) was investigated employing the combination of coagulation/dissolved air flotation, heterogeneous catalytic ozonation and sequencing batch reactor (SBR) processes. Two SBR reactors were separately set up before and after the ozonation unit. The results show that microbubble flotation was more efficient than macrobubble flotation in pollutant removal. Catalytic ozonation with the prepared Fe/activated carbon catalyst significantly enhanced pollutant removal in the second SBR by improving wastewater biodegradability and reducing wastewater microtoxicity. The treatment technique decreased oil, chemical oxygen demand and NH3-N by about 97%, 88% and 91%, respectively, allowing the discharge limits to be met. Therefore, the integrated process with efficient, economical and sustainable advantages was suitable for advanced treatment of real OPW. PMID:26936286

  4. The fate of massive black holes in gas-rich galaxy mergers

    OpenAIRE

    Escala, A.; R. B. Larson; Coppi, P. S.; Mardones, D.

    2006-01-01

    Utilizando simulaciones num ericas SPH, investigamos los efectos de gas sobre la inspiral y la fusi on de una binaria de agujeros negros masivos. Este estudio fue motivado por los discos de gas nucleares muy masivos que se observan en las regiones centrales de galaxias en fusi on. Aqu presentamos los resultados que ampl an el tratamiento de trabajos previos (Escala et al. 2004, 2005) mediante el estudio de la evoluci on de una binaria con diferentes masas de agujeros negros en ...

  5. Alfalfa discovery of the nearby gas-rich dwarf galaxy LEO P. V. Neutral gas dynamics and kinematics

    International Nuclear Information System (INIS)

    We present new H I spectral line imaging of the extremely metal-poor, star-forming dwarf irregular galaxy Leo P. Our H I images probe the global neutral gas properties and the local conditions of the interstellar medium (ISM). The H I morphology is slightly elongated along the optical major axis. We do not find obvious signatures of interaction or infalling gas at large spatial scales. The neutral gas disk shows obvious rotation, although the velocity dispersion is comparable to the rotation velocity. The rotation amplitude is estimated to be V c =15 ± 5 km s–1. Within the H I radius probed by these observations, the mass ratio of gas to stars is roughly 2:1, while the ratio of the total mass to the baryonic mass is ≳15:1. We use this information to place Leo P on the baryonic Tully-Fisher relation, testing the baryonic content of cosmic structures in a sparsely populated portion of parameter space that has hitherto been occupied primarily by dwarf spheroidal galaxies. We detect the signature of two temperature components in the neutral ISM of Leo P; the cold and warm components have characteristic velocity widths of 4.2 ± 0.9 km s–1 and 10.1 ± 1.2 km s–1, corresponding to kinetic temperature upper limits of ∼1100 K and ∼6200 K, respectively. The cold H I component is unresolved at a physical resolution of 200 pc. The highest H I surface densities are observed in close physical proximity to the single H II region. A comparison of the neutral gas properties of Leo P with other extremely metal-deficient (XMD) galaxies reveals that Leo P has the lowest neutral gas mass of any known XMD, and that the dynamical mass of Leo P is more than two orders of magnitude smaller than any known XMD with comparable metallicity.

  6. Catalytic ozonation-biological coupled processes for the treatment of industrial wastewater containing refractory chlorinated nitroaromatic compounds*

    OpenAIRE

    Li, Bing-zhi; Xu, Xiang-Yang; Zhu, Liang

    2010-01-01

    A treatability study of industrial wastewater containing chlorinated nitroaromatic compounds (CNACs) by a catalytic ozonation process (COP) with a modified Mn/Co ceramic catalyst and an aerobic sequencing batch reactor (SBR) was investigated. A preliminary attempt to treat the diluted wastewater with a single SBR resulted in ineffective removal of the color, ammonia, total organic carbon (TOC) and chemical oxygen demand (COD). Next, COP was applied as a pretreatment in order to obtain a bio-c...

  7. Pilot Scale Test to Treat High Concentration Gasification Wastewater Using Catalytic Oxidation and Aerobic Biological Fluid-Bed Combination Process

    Institute of Scientific and Technical Information of China (English)

    LI Na; HUANG Jun-li; WANG Wei; ZHAO Jian-wei; WANG Cui-lin; CUI Chong-wei

    2008-01-01

    The gasitication wastewatet is a kind of typical ocgauic industrial wastewatet with high chemical oxygen demand (COD) and ammonia uitrogen,which could not be completely degraded by the traditional physical,chimical and bidogical method.So it is very important to find an effective treatment process.A combination process of catalytic oxidation with noble metal catalysts and aerobic biological fluid-bed packed with the new uitrastructure biological carriers,which was devdoped by ourselves,was investigated to treat the gasification wastcwater.The pilot scale test with 0.5m3/h influent flow was carried out to investigate the performance of this new combination process.The results showed that the effluent COD was 84.02 mg/L,ananonia nitrogen was 14.15 mg/L,and total phenol was 0.20 mg/L,which could completely meet the Grade I of Wastewater Discharge Standard (GB8978-1996),when the influent average COD was 5564 mg/L,anunonia nitrogen was 237 mg/L,and total phenol was 1100 mg/L.The two catalytic reactors could evidently improve the wastewater biodegradability,and the value of BOD5/COD(B/C) increased from 0.23 to 0.413 in the one-stage catalytic reactor and from 0.273 to 0.421 in two-stage catalytic reactor.The further experiment results showed that the effluent quality of this new combination progess could still meet the discharge standard,aromatic and heterocyclic compounds were degraded effectively in this combination process.

  8. Prediction of Optimum parameters for NO/sub x/ reduction utilizing selective non-catalytic reduction (sncr) technique (thermal DeNO/sub x/ process)

    International Nuclear Information System (INIS)

    In this paper thermal DeNO/sub x/ process for Selective Non-Catalytic removal (SNCR) of nitric oxide from engine exhaust gases has been discussed and optimum parameters i.e optimum temperature, optimum residence time, and optimum molar ratio has been calculated by using CHEMKIN-II software. To run the code exhaust emission data has been obtained from reciprocating engine power plant operating on duel fuel system (40% Natural gas and 60% HFO). Finally it is concluded that if the conditions prescribed as predicted results are met in the exhaust stream, then with ammonia injection a substantial decrease in NO/sub x/ (about 96%) can be achieved. Sources of NO/sub x/ formation and different NO/sub x/ control techniques are also discussed in the paper. (author)

  9. Using a dual plasma process to produce cobalt--polypyrrole catalysts for the oxygen reduction reaction in fuel cells -- part I: characterisation of the catalytic activity and surface structure

    CERN Document Server

    Walter, Christian; Vyalikh, Denis; Brüser, Volker; Quade, Antje; Weltmann, Klaus-Dieter; 10.1149/2.078208jes

    2012-01-01

    A new dual plasma coating process to produce platinum-free catalysts for the oxygen reduction reaction in a fuel cell is introduced. The catalysts thus produced were analysed with various methods. Electrochemical characterisation was carried out by cyclic voltammetry, rotating ring- and rotating ring-disk electrode. The surface porosity of the different catalysts thus obtained was characterised with the nitrogen gas adsorption technique and scanning electron microscopy was used to determine the growth mechanisms of the films. It is shown that catalytically active compounds can be produced with this dual plasma process. Furthermore, the catalytic activity can be varied significantly by changing the plasma process parameters. The amount of H$_2$O$_2$ produced was calculated and shows that a 2 electron mechanism is predominant. The plasma coating mechanism does not significantly change the surface BET area and pore size distribution of the carbon support used. Furthermore, scanning electron microscopy pictures o...

  10. 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.

  11. 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.

  12. Developing a Steady-state Kinetic Model for Industrial Scale Semi-Regenerative Catalytic Naphtha Reforming Process

    Directory of Open Access Journals (Sweden)

    Seif Mohaddecy, R.

    2014-05-01

    Full Text Available Due to the demand for high octane gasoline as a transportation fuel, the catalytic naphtha reformer has become one of the most important processes in petroleum refineries. In this research, the steady-state modelling of a catalytic fixed-bed naphtha reforming process to predict the momentous output variables was studied. These variables were octane number, yield, hydrogen purity, and temperature of all reforming reactors. To do such a task, an industrial scale semi-regenerative catalytic naphtha reforming unit was studied and modelled. In addition, to evaluate the developed model, the predicted variables i.e. outlet temperatures of reactors, research octane number, yield of gasoline and hydrogen purity were compared against actual data. The results showed that there is a close mapping between the actual and predicted variables, and the mean relative absolute deviation of the mentioned process variables were 0.38 %, 0.52 %, 0.54 %, 0.32 %, 4.8 % and 3.2 %, respectively.

  13. Handbook of gasifiers and gas-treatment systems. [39 gasification processes and 40 gas processing systems

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, R.D.

    1982-09-01

    In February 1976, the Energy Research and Development Administration (ERDA) published the Handbook of Gasifiers and Gas Treatment Systems. The intent of this handbook was to provide a ready reference to systems that are or may be applicable to coal conversion technology. That handbook was well received by users and was subsequently reprinted many times. The Department of Energy (successor agency to the ERDA) expands, revises and updates the Handbook in this volume. This new Handbook is not intended as a comparative evaluation, but rather as an impartial reference on recent and current technology. The Handbook now presents 39 gasification technologies and 40 gas processing systems that are or may be applicable to coal conversion technology. The information presented has been approved or supplied by the particular licensor/developer.

  14. ALFALFA Discovery of the Nearby Gas-rich Dwarf Galaxy Leo P. V. Neutral Gas Dynamics and Kinematics

    CERN Document Server

    Bernstein-Cooper, Elijah Z; Elson, Edward C; Warren, Steven R; Chengalur, Jayaram; Skillman, Evan D; Adams, Elizabeth A K; Bolatto, Alberto D; Giovanelli, Riccardo; Haynes, Martha P; McQuinn, Kristen B W; Pardy, Stephen A; Rhode, Katherine L; Salzer, John J

    2014-01-01

    We present new HI spectral line imaging of the extremely metal-poor, star-forming dwarf irregular galaxy Leo P. Our HI images probe the global neutral gas properties and the local conditions of the interstellar medium (ISM). The HI morphology is slightly elongated along the optical major-axis. We do not find obvious signatures of interaction or infalling gas at large spatial scales. The neutral gas disk shows obvious rotation, although the velocity dispersion is comparable to the rotation velocity. The rotation amplitude is estimated to be V_c = 15 +/- 5 km/s. Within the HI radius probed by these observations, the mass ratio of gas to stars is roughly 2:1, while the ratio of the total mass to the baryonic mass is ~15:1. We use this information to place Leo P on the baryonic Tully-Fisher relation, testing the baryonic content of cosmic structures in a sparsely populated portion of parameter space that has hitherto been occupied primarily by dwarf spheroidal galaxies. We detect the signature of two temperature ...

  15. Fine particle collection of an electrostatic precipitator in CO2-rich gas conditions for oxy-fuel combustion.

    Science.gov (United States)

    Han, Bangwoo; Kim, Hak Joon; Kim, Yong Jin

    2010-10-01

    The collection of particles in CO(2)-enriched environments has long been important for the capture of CO(2) in order to clean gases via oxy-fuel combustion. We here report on the collection characteristics of fine and ultrafine particles using an electrostatic precipitator (ESP) in a CO(2)-enriched atmosphere. In order to understand the characteristics of particle collection in CO(2)-rich gas mixtures, the ionic properties of a CO(2)-enriched atmosphere was also investigated. The electrical mobility of the ions in a CO(2)-enriched atmosphere was found to be about 0.56 times that found in a conventional air atmosphere, due to the higher mass of CO(2) gas compared to that of air. The low electrical mobility of ions resulted in a low corona current under CO(2)-enriched conditions. The collection efficiency of particles in a CO(2)-rich atmosphere for a given power consumption was thus somewhat lower than that found in air, due to the low quantity of particle charging in CO(2)-enriched air. At the same time, higher temperatures led to the higher electrical mobility of ions, which resulted in a greater collection efficiency for a given power. The presence of a negative corona also led to a greater collection efficiency of particles in an ESP than that achieved for a positive corona. PMID:20692021

  16. Catalytic oxidation of gas-phase elemental mercury by nano-Fe2O3

    Institute of Scientific and Technical Information of China (English)

    Fanhai Kong; Jianrong Qiu; Hao Liu; Ran Zhao; Zhihui Ai

    2011-01-01

    Heterogeneous oxidation of gas-phase Hg0 by nano-Fe2O3 was investigated on a fixed bed reactor, and the effects of oxygen concentration, bed temperature, water vapour concentration and particle size have been discussed. The results showed that Hg0 could be oxidized by active oxygen atom on the surface of nano-Fe2O3 as well as lattice oxygen in nano-Fe2O3. Among the factors that affect Hg0 oxidation by nano-Fe2O3, bed temperature plays an important role. More than 40% of total mercury was oxidized at 300℃,however, the test temperature at 400℃ could cause sintering of nano-catalyst, which led to a lower efficiency of Hg0 oxidation. The increase of oxygen concentration could promote mercury oxidation and led to higher Hg0 oxidation efficiency. No obvious mercury oxidation was detected in the pure N2 atmosphere, which indicates that oxygen is required in the gas stream for mercury oxidation. The presence of water vapour showed different effects on mercury oxidation depending on its concentration. The lower content of water vapour could promote mercury oxidation, while the higher content of water vapour inhibits mercury oxidation.

  17. Mathematical simulation of the process of condensing natural gas

    Directory of Open Access Journals (Sweden)

    Tastandieva G.M.

    2015-01-01

    Full Text Available Presents a two-dimensional unsteady model of heat transfer in terms of condensation of natural gas at low temperatures. Performed calculations of the process heat and mass transfer of liquefied natural gas (LNG storage tanks of cylindrical shape. The influence of model parameters on the nature of heat transfer. Defined temperature regimes eliminate evaporation by cooling liquefied natural gas. The obtained dependence of the mass flow rate of vapor condensation gas temperature. Identified the possibility of regulating the process of “cooling down” liquefied natural gas in terms of its partial evaporation with low cost energy.

  18. Neutron-capture elements in the s- and r-process-rich stars: Constraints on neutron-capture nucleosynthesis processes

    CERN Document Server

    Zhang, B; Zhou, G; Zhang, Bo; Ma, Kun; Zhou, Guide

    2006-01-01

    The chemical abundances of the very metal-poor double-enhanced stars are excellent information for setting new constraints on models of neutron-capture processes at low metallicity. These stars are known as s+r stars, since they show enhancements of both s-process and r-process elements. The observed abundance ratios for the double-enhanced stars can be explained by those of stars that were polluted by an AGB star and subsequently accreted very significant amounts of r-process material out of an AIC (accretion-induced collapse) or Type 1.5 supernova. In this paper we present for the first time an attempt to fit the elemental abundances observed in the s- and r-rich, very metal-poor stars using a parametric model and suggest a new concept of component coefficients to describe the contributions of the individual neutron-capture processes to double-enhanced stars. We find that the abundance ratios of these stars are best fitted by enrichments of s- and r-process material. The overlap factor in the AGB stars wher...

  19. Distribution of Hydrate Inhibitors in Processing of Gas-Condensate

    OpenAIRE

    Jonassen, Anette Hartveit

    2013-01-01

    The formation of gas hydrates have been known to cause serious problems with blockages in natural gas pipelines, wellbore and natural gas processing units. The offshore sector of the North Sea comes into focus owing to factors such as low temperature, high pressure because of deep water fields, great depth of the subsea environment and remote locations that are factors underlying the increased hydrate formation. Hydrates are formed in multiphase transport comprising gas, condensate and water....

  20. First-Principles Molecular Dynamics Studies of Organometallic Complexes and Homogeneous Catalytic Processes.

    Science.gov (United States)

    Vidossich, Pietro; Lledós, Agustí; Ujaque, Gregori

    2016-06-21

    Computational chemistry is a valuable aid to complement experimental studies of organometallic systems and their reactivity. It allows probing mechanistic hypotheses and investigating molecular structures, shedding light on the behavior and properties of molecular assemblies at the atomic scale. When approaching a chemical problem, the computational chemist has to decide on the theoretical approach needed to describe electron/nuclear interactions and the composition of the model used to approximate the actual system. Both factors determine the reliability of the modeling study. The community dedicated much effort to developing and improving the performance and accuracy of theoretical approaches for electronic structure calculations, on which the description of (inter)atomic interactions rely. Here, the importance of the model system used in computational studies is highlighted through examples from our recent research focused on organometallic systems and homogeneous catalytic processes. We show how the inclusion of explicit solvent allows the characterization of molecular events that would otherwise not be accessible in reduced model systems (clusters). These include the stabilization of nascent charged fragments via microscopic solvation (notably, hydrogen bonding), transfer of charge (protons) between distant fragments mediated by solvent molecules, and solvent coordination to unsaturated metal centers. Furthermore, when weak interactions are involved, we show how conformational and solvation properties of organometallic complexes are also affected by the explicit inclusion of solvent molecules. Such extended model systems may be treated under periodic boundary conditions, thus removing the cluster/continuum (or vacuum) boundary, and require a statistical mechanics simulation technique to sample the accessible configurational space. First-principles molecular dynamics, in which atomic forces are computed from electronic structure calculations (namely, density

  1. Acoustic and Visul Study of Bubble Formation Processes in Bubble Columns Staged with Fibrous Catalytic Layers

    Czech Academy of Sciences Publication Activity Database

    Höller, V.; Růžička, Marek; Drahoš, Jiří; Kiwi-Minsker, L.; Renken, A.

    79-80, - (2003), s. 151-157. ISSN 0920-5861 Institutional research plan: CEZ:AV0Z4072921 Keywords : bubble formation * fibrous catalytic layers * staged bubble column Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.627, year: 2003

  2. In vitro genotoxicity of chlorinated drinking water processed from humus-rich surface water

    Energy Technology Data Exchange (ETDEWEB)

    Liimatainen, A.; Grummt, T.

    1988-11-01

    Chlorination by-products of drinking waters are capable of inducing sister chromatid exchanges (SCE) and chromosome aberrations (CA) in vitro, in addition to their mutagenic activity in the Ames test. Finnish drinking waters, processed from humus-rich surface water using chlorine disinfection, have been found to be highly mutagenic in the Ames' test. The highest activities have been found in the acidic, non-volatile fraction of the water concentrates using tester strain TA100 without metabolic activation by S9mix. The mutagenicities have varied between 500 and 14,000 induced revertants per liter. These figures are one to two magnitudes higher than those reported elsewhere. The authors studied five Finnish drinking water samples for their potency to exert genotoxic effects, SCEs and CAs, in mammalian cells in vitro (human peripheral lymphocytes and Chinese hamster lung fibroblasts).

  3. Gelling process of sodium alginate with bivalent ions rich microsphere: Nature of bivalent ions

    Science.gov (United States)

    Mauri, Marco; Vicini, Silvia; Castellano, Maila

    2016-05-01

    In the paper we present a new approach for obtaining a controlled gelling process of sodium alginate, based on the quantity of bivalent ions rich alginate micro-beads added as crosslinkers. Typically, calcium ions are used in gelation of alginate solutions. In this study we present different gelling systems realized with alginate microspheres, made by electrospinning methodology, enriched with different bivalent ions (Ca2+, Ba2+ and Mg2+). The microspheres were characterized under the point of view of the morphology by OM and as the ions content. Realized gels were characterized in light of the amount of the ions added to the alginate solution, and in light of the different dimensions of the micro-beads, using rheological measurements to assess the variation in the storage modulus (G'), loss modulus (G″) and complex viscosity (η*).

  4. Treatment of nitrogen-rich wastewater using partial nitrification and anammox in the CANON process.

    Science.gov (United States)

    Third, K A; Paxman, J; Schmid, M; Strous, M; Jetten, M S M; Cord-Ruwisch, R

    2005-01-01

    Partial nitrification combined with Anammox in a single reactor (the CANON process) is an energy-efficient N-removal technology that could substantially lower the N-load of a WWTP by separate treatment of nitrogen-rich side streams, preventing the need for extensive expansion and reducing the total energy requirement. This study looks at the enrichment of Anammox from activated sludge and its application in the CANON process on lab-scale. The aim was to identify the critical process control parameters necessary for successful operation of CANON. An Anammox culture capable of removing 0.6 kg N/m3/d was enriched in 14 weeks in a sequencing batch reactor. Nitrifying biomass was inoculated into the Anammox reactor (10% v/v) together with limited oxygen supply (culture. The small flocs formed by the biomass (< 1000 microm) were sensitive to low O2 concentrations (< 0.1 mg/L) which prevented simultaneous nitrification and Anammox. Operation with 20 min aerobiosis and 30 min anaerobiosis was necessary to achieve sustained, completely autotrophic N-removal for an extended period at a rate of 0.08 kg N/m3/d. Essential process control parameters for stable CANON operation were the nitrite concentration, oxygen concentration, pH and the temperature. PMID:16235745

  5. Floating island for extracting or processing gas

    Energy Technology Data Exchange (ETDEWEB)

    Poeppel, F.O.

    1979-09-25

    The described floating island for the extraction of gas from the sea a plurality of buoyancy units positioned on a base plate with columns extending upward therefrom at a height approximately the wave height expected. A platform containing gas liquefaction apparatus is positioned on the top of the columns. The buoyancy units are selected so that when the island is free floating, the columns project more than half way from the water.

  6. Catalytic Preparation of Methyl Formate from Methanol over Silver

    Institute of Scientific and Technical Information of China (English)

    YANG Zhi; LI Jing; YANG Xiang-guang; WU Yue

    2005-01-01

    A catalytic reaction over a silver catalyst performed in an unregarded temperature region(473-873 K) with a long catalytic lifetime for the production of methyl formate from methanol was provided as a potential preparing route. The optimal yield of methyl formate(ca. 14.8%) with a selectivity >90% was obtained at about 573 K. Because α-oxygen species and bulk oxygen species coexist in the unregarded temperature region, a synergistic process concerning α-oxygen species and bulk oxygen species was proved over Oα -rich and Oγ-rich samples.

  7. Alfalfa discovery of the nearby gas-rich dwarf galaxy LEO P. V. Neutral gas dynamics and kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein-Cooper, Elijah Z.; Pardy, Stephen A. [Department of Astronomy, University of Wisconsin, 475 N Charter Street, Madison, WI 53706 (United States); Cannon, John M., E-mail: ezbc@astro.wisc.edu, E-mail: spardy@astro.wisc.edu, E-mail: jcannon@macalester.edu [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); and others

    2014-08-01

    We present new H I spectral line imaging of the extremely metal-poor, star-forming dwarf irregular galaxy Leo P. Our H I images probe the global neutral gas properties and the local conditions of the interstellar medium (ISM). The H I morphology is slightly elongated along the optical major axis. We do not find obvious signatures of interaction or infalling gas at large spatial scales. The neutral gas disk shows obvious rotation, although the velocity dispersion is comparable to the rotation velocity. The rotation amplitude is estimated to be V {sub c} =15 ± 5 km s{sup –1}. Within the H I radius probed by these observations, the mass ratio of gas to stars is roughly 2:1, while the ratio of the total mass to the baryonic mass is ≳15:1. We use this information to place Leo P on the baryonic Tully-Fisher relation, testing the baryonic content of cosmic structures in a sparsely populated portion of parameter space that has hitherto been occupied primarily by dwarf spheroidal galaxies. We detect the signature of two temperature components in the neutral ISM of Leo P; the cold and warm components have characteristic velocity widths of 4.2 ± 0.9 km s{sup –1} and 10.1 ± 1.2 km s{sup –1}, corresponding to kinetic temperature upper limits of ∼1100 K and ∼6200 K, respectively. The cold H I component is unresolved at a physical resolution of 200 pc. The highest H I surface densities are observed in close physical proximity to the single H II region. A comparison of the neutral gas properties of Leo P with other extremely metal-deficient (XMD) galaxies reveals that Leo P has the lowest neutral gas mass of any known XMD, and that the dynamical mass of Leo P is more than two orders of magnitude smaller than any known XMD with comparable metallicity.

  8. Amplification and Scintillation Properties of Oxygen-Rich Gas Mixtures for Optical-TPC Applications

    OpenAIRE

    Weissman, L.; Gai, M.; Breskin, A.; Chechik, R.; Dangendorf, V.; Tittelmeier, K.; H.R. Weller

    2006-01-01

    We studied electron amplification and light emission from avalanches in oxygen-containing gas mixtures. The mixtures investigated in this work included, among others, CO2 and N2O mixed with Triethylamine (TEA) or N2. Double-Step Parallel Gap (DSPG) multipliers and THick Gas Electron Multipliers (THGEM) were investigated. High light yields were measured from CO2+N2 and CO2+TEA, though with different emission spectra. We observed the characteristic wave-length emission of N2 and of TEA and used...

  9. Process for the production of hydrogen/deuterium-containing gas

    International Nuclear Information System (INIS)

    A process for the production of hydrogen/deuterium-containing gas is described in which the enriched condensate obtained from the production of a hydrogen/deuterium-containing gas mixture is collected and subjected to a direct exchange of isotopes with the feedsteam admitted to the process. Such condensate can be brought into direct exchange of isotopes with the gas water vapor mixture within the process, viz. ahead of the CO conversion section. The exchange of isotopes may be performed according to the counter-current principle. If it is intended to maintain in the hydrogen/deuterium-containing gas a certain definite content of water vapor whose phase condition is superior to the condition achieved when using normal cooling water, this gas, at least 0.6 kg/m3 of gas, is subjected to an exchange of isotopes with the water fed additionally into the process

  10. Possible discovery of the r-process characteristics in the abundances of metal-rich barium stars

    CERN Document Server

    Cui, W Y; Shi, J R; Zhao, G; Wang, W J; Niu, P

    2014-01-01

    We study the abundance distributions of a sample of metal-rich barium stars provided by Pereira et al. (2011) to investigate the s- and r-process nucleosynthesis in the metal-rich environment. We compared the theoretical results predicted by a parametric model with the observed abundances of the metal-rich barium stars. We found that six barium stars have a significant r-process characteristic, and we divided the barium stars into two groups: the r-rich barium stars ($C_r>5.0$, [La/Nd]\\,$<0$) and normal barium stars. The behavior of the r-rich barium stars seems more like that of the metal-poor r-rich and CEMP-r/s stars. We suggest that the most possible formation mechanism for these stars is the s-process pollution, although their abundance patterns can be fitted very well when the pre-enrichment hypothesis is included. The fact that we can not explain them well using the s-process nucleosynthesis alone may be due to our incomplete knowledge on the production of Nd, Eu, and other relevant elements by the ...

  11. Catalytic gasification of oil-shales

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, A.; Avakyan, T. [I.M. Gubkin Russian State Univ. of Oil and Gas, Moscow (Russian Federation); Strizhakova, Yu. [Samara State Univ. (Russian Federation)

    2012-07-01

    Nowadays, the problem of complex usage of solid fossil fuels as raw materials for obtaining of motor fuels and chemical products is becoming increasingly important. A one of possible solutions of the problem is their gasification with further processing of gaseous and liquid products. In this work we have investigated the process of thermal and catalytic gasification of Baltic and Kashpir oil-shales. We have shown that, as compared with non-catalytic process, using of nickel catalyst in the reaction increases the yield of gas, as well as hydrogen content in it, and decreases the amount of liquid products. (orig.)

  12. Gasification of Empty Fruit Bunch for Hydrogen Rich Fuel Gas Production

    Directory of Open Access Journals (Sweden)

    W.A.K.G. Wan Azlina

    2011-01-01

    Full Text Available A study on gasification of Empty Fruit Bunch (EFB, a waste of the palm oil industry is investigated. The composition and particle size distribution of feedstock are determined and the thermal degradation behaviour is analysed by a thermogravimetric analysis (TGA. Then 300 g h-1 fluidized bed bench scale gasification unit is used to investigate the effect of the operating parameters on biomass gasification namely reactor temperature in the range of 700-1000C and feedstock particle size in the range of 0.3-1.0 mm. The main gas species generated, as identified by a Gas Chromatography (GC, are H2, CO, CO2 and CH4. With temperature increasing from 700 to 1000C, the total gas yield is enhanced greatly and has reached the maximum value (~ 92 wt. %, on the raw biomass sample basis at 1000C with big portions of H2 (38.02 vol.% and CO (36.36 vol.%. Feedstock particle size shows some influence on the H2, CO and CH4 yields. The feedstock particle size of 0.3 to 0.5 mm, is found to generate a higher H2 yield (33.12 vol.% and higher LHV of gas product (17.19 MJ m-3.

  13. The role of OH in the chemical evolution of protoplanetary disks II. Gas-rich environments

    CERN Document Server

    Molano, Germán Chaparro

    2012-01-01

    Context. We present a method for including gas extinction of cosmic-ray-generated UV photons in chemical models of the midplane of protoplanetary disks, focusing on its implications on ice formation and chemical evolution. Aims. Our goal is to improve on chemical models by treating cosmic rays, the main source of ionization in the midplane of the disk, in a way that is consistent with current knowledge of the gas and grain environment present in those regions. We trace the effects of cosmic rays by identifying the main chemical reaction channels and also the main contributors to the gas opacity to cosmic-ray-induced UV photons. This information is crucial in implementing gas opacities for cosmic-ray-induced reactions in full 2D protoplanetary disk models. Methods. We considered time-dependent chemical models within the range 1-10 AU in the midplane of a T Tauri disk. The extinction of cosmic-ray-induced UV photons by gaseous species was included in the calculation of photorates at each timestep. We integrated...

  14. Optimizing carbon efficiency of jet fuel range alkanes from cellulose co-fed with polyethylene via catalytically combined processes.

    Science.gov (United States)

    Zhang, Xuesong; Lei, Hanwu; Zhu, Lei; Zhu, Xiaolu; Qian, Moriko; Yadavalli, Gayatri; Yan, Di; Wu, Joan; Chen, Shulin

    2016-08-01

    Enhanced carbon yields of renewable alkanes for jet fuels were obtained through the catalytic microwave-induced co-pyrolysis and hydrogenation process. The well-promoted ZSM-5 catalyst had high selectivity toward C8-C16 aromatic hydrocarbons. The raw organics with improved carbon yield (∼44%) were more principally lumped in the jet fuel range at the catalytic temperature of 375°C with the LDPE to cellulose (representing waste plastics to lignocellulose) mass ratio of 0.75. It was also observed that the four species of raw organics from the catalytic microwave co-pyrolysis were almost completely converted into saturated hydrocarbons; the hydrogenation process was conducted in the n-heptane medium by using home-made Raney Ni catalyst under a low-severity condition. The overall carbon yield (with regards to co-reactants of cellulose and LDPE) of hydrogenated organics that mostly match jet fuels was sustainably enhanced to above 39%. Meanwhile, ∼90% selectivity toward jet fuel range alkanes was attained. PMID:27126079

  15. Thermodynamic and kinetic study of phenol degradation by a non-catalytic wet air oxidation process.

    Science.gov (United States)

    Lefèvre, Sébastien; Boutin, Olivier; Ferrasse, Jean-Henry; Malleret, Laure; Faucherand, Rémy; Viand, Alain

    2011-08-01

    This work is dedicated to an accurate evaluation of thermodynamic and kinetics aspects of phenol degradation using wet air oxidation process. Phenol is a well known polluting molecule and therefore it is important having data of its behaviour during this process. A view cell is used for the experimental study, with an internal volume of 150 mL, able to reach pressures up to 30 MPa and temperatures up to 350°C. Concerning the thermodynamic phase equilibria, experimental and modelling results are obtained for different binary systems (water/nitrogen, water/air) and ternary system (water/nitrogen/phenol). The best model is the Predictive Soave Redlich Kwong one. This information is necessary to predict the composition of the gas phase during the process. It is also important for an implementation in a process simulation. The second part is dedicated to kinetics evaluation of the degradation of phenol. Different compounds have been detected using GC coupled with a MS. A kinetic scheme is deduced, taking into account the evolution of phenol, hydroquinones, catechol, resorcinol and acetic acid. The kinetic parameters are calculated for this scheme. These data are important to evaluate the evolution of the concentration of the different polluting molecules during the process. A simplified kinetic scheme, which can be easily implemented in a process simulation, is also determined for the direct degradation of phenol into H(2)O and CO(2). The Arrhenius law data obtained for the phenol disappearance are the following: k=1.8×10(6)±3.9×10(5)M(-1)s(-1) (pre-exponential factor) and E(a)=77±8 kJ mol(-1) (activation energy). PMID:21700312

  16. Alfalfa discovery of the nearby gas-rich dwarf galaxy Leo P. IV. Distance measurement from LBT optical imaging

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W.; Skillman, Evan D.; Berg, Danielle [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Salzer, John J.; Rhode, Katherine L. [Department of Astronomy, Indiana University, 727 East 3rd Street, Bloomington, IN 47405 (United States); Adams, Elizabeth A. K.; Giovanelli, Riccardo; Haynes, Martha P. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Dolphin, Andrew, E-mail: kmcquinn@astro.umn.edu, E-mail: skillman@astro.umn.edu, E-mail: berg@astro.umn.edu, E-mail: jcannon@macalester.edu, E-mail: rhode@astro.indiana.edu, E-mail: slaz@astro.indiana.edu, E-mail: betsey@astro.cornell.edu, E-mail: riccardo@astro.cornell.edu, E-mail: haynes@astro.cornell.edu [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States)

    2013-12-01

    Leo P is a low-luminosity dwarf galaxy discovered through the blind H I Arecibo Legacy Fast ALFA survey. The H I and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with both active star formation and an underlying older population, as well as an extremely low oxygen abundance. Here, we measure the distance to Leo P by applying the tip of the red giant branch (TRGB) distance method to photometry of the resolved stellar population from new Large Binocular Telescope V and I band imaging. We measure a distance modulus of 26.19{sub −0.50}{sup +0.17} mag corresponding to a distance of 1.72{sub −0.40}{sup +0.14} Mpc. Although our photometry reaches 3 mag below the TRGB, the sparseness of the red giant branch yields higher uncertainties on the lower limit of the distance. Leo P is outside the Local Group with a distance and velocity consistent with the local Hubble flow. While located in a very low-density environment, Leo P lies within ∼0.5 Mpc of a loose association of dwarf galaxies which include NGC 3109, Antlia, Sextans A, and Sextans B, and 1.1 Mpc away from its next nearest neighbor, Leo A. Leo P is one of the lowest metallicity star-forming galaxies known in the nearby universe, comparable in metallicity to I Zw 18 and DDO 68, but with stellar characteristics similar to dwarf spheriodals (dSphs) in the Local Volume such as Carina, Sextans, and Leo II. Given its physical properties and isolation, Leo P may provide an evolutionary link between gas-rich dwarf irregular galaxies and dSphs that have fallen into a Local Group environment and been stripped of their gas.

  17. Alfalfa discovery of the nearby gas-rich dwarf galaxy Leo P. IV. Distance measurement from LBT optical imaging

    International Nuclear Information System (INIS)

    Leo P is a low-luminosity dwarf galaxy discovered through the blind H I Arecibo Legacy Fast ALFA survey. The H I and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with both active star formation and an underlying older population, as well as an extremely low oxygen abundance. Here, we measure the distance to Leo P by applying the tip of the red giant branch (TRGB) distance method to photometry of the resolved stellar population from new Large Binocular Telescope V and I band imaging. We measure a distance modulus of 26.19−0.50+0.17 mag corresponding to a distance of 1.72−0.40+0.14 Mpc. Although our photometry reaches 3 mag below the TRGB, the sparseness of the red giant branch yields higher uncertainties on the lower limit of the distance. Leo P is outside the Local Group with a distance and velocity consistent with the local Hubble flow. While located in a very low-density environment, Leo P lies within ∼0.5 Mpc of a loose association of dwarf galaxies which include NGC 3109, Antlia, Sextans A, and Sextans B, and 1.1 Mpc away from its next nearest neighbor, Leo A. Leo P is one of the lowest metallicity star-forming galaxies known in the nearby universe, comparable in metallicity to I Zw 18 and DDO 68, but with stellar characteristics similar to dwarf spheriodals (dSphs) in the Local Volume such as Carina, Sextans, and Leo II. Given its physical properties and isolation, Leo P may provide an evolutionary link between gas-rich dwarf irregular galaxies and dSphs that have fallen into a Local Group environment and been stripped of their gas

  18. Catalytic performance of cerium iron complex oxides for partial oxidation of methane to synthesis gas

    Institute of Scientific and Technical Information of China (English)

    LI Kongzhai; WANG Hua; WEI Yonggang; LIU Mingchun

    2008-01-01

    The cerium iron complex oxides oxygen carder was prepared by the co-precipitation method. The reactions between methane and lattice oxygen from the complex oxides were investigated in a fixed micro-reactor system. The reduced oxygen carrier could be re-oxidized by air and its initial state could be restored. The characterizations of the oxygen carriers were studied using XRD, O2-TPD, and H2-TPR. The results showed that the bulk lattice oxygen of CeO2-Fe2O3 was found to be suitable for the partial oxidation of methane to synthesis gas. There were two kinds of oxygen species on the oxygen carder: the stronger oxygen species that was responsible for the complete oxidation of methane, and the weaker oxygen species (bulk lattice oxygen) that was responsible for the selective oxidation of methane to CO and H2 at a higher temperature. Then, the lost bulk lattice oxygen could be selectively supplemented by air re-oxidation at an appropriate reaction con-dition. CeFeO3 appeared on the oxygen carrier after 10 successive redox cycles, however, it was not bad for the selectivity of CO and H2.

  19. Gas processing at DOE nuclear facilities

    International Nuclear Information System (INIS)

    The term open-quotes Gas Processingclose quotes has many possible meanings and understandings. In this paper, and panel, we will be using it to generally mean the treatment of gas by methods other than those common to HVAC and Nuclear Air Treatment. This is only a working guideline not a rigorous definition. Whether a rigorous definition is desirable, or even possible is a question for some other forum. Here we will be discussing the practical aspects of what open-quotes Gas Processingclose quotes includes and how existing Codes, Standards and industry experience can, and should, apply to DOE and NRC Licensed facilities. A major impediment to use of the best engineering and technology in many nuclear facilities is the administrative mandate that only systems and equipment that meet specified open-quotes nuclearclose quotes documents are permissible. This paper will highlight some of the limitations created by this approach

  20. Frictional processes in smectite-rich gouges sheared at slow to high slip rates

    Science.gov (United States)

    Aretusini, Stefano; Mittempergher, Silvia; Gualtieri, Alessandro; Di Toro, Giulio

    2015-04-01

    The slipping zones of shallow sections of megathrusts and of large landslides are often smectite-rich (e.g., montmorillonite type). Consequently, similar "frictional" processes operating at high slip rates (> 1 m/s) might be responsible of the large slips estimated in megathrust (50 m for the 2011 Tohoku Mw 9.1 earthquake) and measured in large landslides (500 m for the 1963 Vajont slide, Italy). At present, only rotary shear apparatuses can reproduce simultaneously the large slips and slip rates of these events. Noteworthy, the frictional processes proposed so far (thermal and thermochemical pressurization, etc.) remain rather obscure. Here we present preliminary results obtained with the ROtary Shear Apparatus (ROSA) installed at Padua University. Thirty-one experiments were performed at ambient conditions on pure end-members of (1) smectite-rich standard powders (STx-1b: ~68 wt% Ca-montmorillonite, ~30 wt% opal-CT and ~2 wt% quartz), (2) quartz powders (qtz) and (3) on 80:20 = Stx-1b:qtz mixtures. The gouges were sandwiched between two (1) hollow (25/15 mm external/internal diameter) or (2) solid (25 mm in diameter) stainless-steel made cylinders and confined by inner and outer Teflon rings (only outer for solid cylinders). Gouges were sheared at a normal stress of 5 MPa, slip rates V from 300 μm/s to 1.5 m/s and total slip of 3 m. The deformed gouges were investigated with quantitative (Rietveld method with internal standard) X-ray powder diffraction (XRPD) and Scanning Electron Microscopy (SEM). In the smectite-rich standard endmember, (1) for 300 μm/s ≤ V ≤ 0.1 m/s, initial friction coefficient (μi) was 0.6±0.05 whereas the steady-state friction coefficient (μss) was velocity and slip strengthening (μss 0.85±0.05), (2) for 0.1 m/s 0.8 m/s, velocity and slip weakening (μi = 0.7±0.1 and μss = 0.25±0.05). In the 80:20 Stx-1b:qtz mixtures, (1) for 300 μm/s ≤ V ≤ 0.1 m/s, μi ranged was 0.7±0.05 and increased with slip to μss = 0.77±0

  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. Catalytic partial oxidation of coke oven gas to syngas in an oxygen permeation membrane reactor combined with NiO/MgO catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhibin; Ding, Weizhong; Zhang, Yunyan; Lu, Xionggang; Zhang, Yuwen; Shen, Peijun [Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, No. 275 Mail box, 149 Yanchang Road, Shanghai 200072 (China)

    2010-06-15

    A high oxygen permeability and sufficient chemical and mechanical stability mixed ion and electron conductivity membrane to withstand the hash strong oxidation and reduction working conditions is significant for the membrane reactor to commercial-scale plant. In this paper, a disk-shaped Ba{sub 1.0}Co{sub 0.7}Fe{sub 0.2}Nb{sub 0.1}O{sub 3-{delta}} membrane was applied to a membrane reactor for the partial oxidation of methane in coke oven gas (COG) to syngas. The reaction was carried out using NiO/MgO solid solution catalyst by feeding COG. The reforming process was performed successfully; 95% CH{sub 4} conversion, 80% H{sub 2} selectivity, 106% CO selectivity and 16.3 ml cm{sup -2} min{sup -1} oxygen permeation flux were achieved at 1148 K. The reaction has been steadily carried out for more than 100 h. The NiO/MgO catalyst used in the membrane reactor exhibited good catalytic activity and resistance to coking in the COG atmosphere. Characterization of the membrane surface by SEM and XRD after long life test showed that both the surface exposed to the air side and reaction side still preserved the Perovskite structure which is implied that the practical application of this membrane as membrane reactor for partial oxidation of COG is promising. (author)

  3. Setup with Laser Ionization in Gas Cell for Production and Study of Neutron-Rich Heavy Nuclei

    Science.gov (United States)

    Zagrebaev, V. I.; Zemlyanoy, S. G.; Kozulin, E. M.; Kudryavtsev, Yu.; Fedosseev, V.; Bark, R.; Janas, Z.; Othman, H. A.

    2015-11-01

    The present limits of the upper part of the nuclear map are very close to stability while the unexplored area of heavy neutron-rich nuclides along the neutron closed shell N=126 is extremely important for nuclear astrophysics investigations and, in particular, for the understanding of the r-process of astrophysical nucleosynthesis. This area of the nuclear map can be reached neither in fusion-fission reactions nor in fragmentation processes widely used nowadays for the production of exotic nuclei. A new way was recently proposed for the production of these nuclei via low-energy multi-nucleon transfer reactions. The estimated yields of neutron-rich nuclei are found to be significantly high in such reactions and several tens of new nuclides can be produced, for example, in the near-barrier collision of 136Xe with 208Pb. A new setup is proposed to produce and study heavy neutron-rich nuclei located along the neutron closed shell N=126.

  4. WATER-GAS SHIFT WITH INTEGRATED HYDROGEN SEPARATION PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Maria Flytzani-Stephanopoulos, PI; Jerry Meldon, Co-PI; Xiaomei Qi

    2002-12-01

    Optimization of the water-gas shift (WGS) reaction system for hydrogen production for fuel cells is of particular interest to the energy industry. To this end, it is desirable to couple the WGS reaction to hydrogen separation using a semi-permeable membrane, with both processes carried out at high temperatures to improve reaction kinetics and permeation. Reduced equilibrium conversion of the WGS reaction at high temperatures is overcome by product H{sub 2} removal via the membrane. This project involves fundamental research and development of novel cerium oxide-based catalysts for the water-gas-shift reaction and the integration of these catalysts with Pd-alloy H{sub 2}-separation membranes supplying high purity hydrogen for fuel cell use. Conditions matching the requirements of coal gasifier-exit gas streams will be examined in the project. The first-year screening studies of WGS catalysts identified Cu-ceria as the most promising high-temperature shift catalyst for integration with H{sub 2}-selective membranes. Formulations containing iron oxide were found to deactivate in the presence of CO{sub 2}, and were thus eliminated from further consideration. Cu-containing ceria catalysts, on the other hand, showed high stability in CO{sub 2}-rich gases. This type gas will be present over much of the catalyst, as the membrane removes the hydrogen produced from the shift reaction. Several catalyst formulations were prepared, characterized and tested in the first year of study. Details from the catalyst development and testing work were given in our first annual technical report. Hydrogen permeation through Pd and Pd-alloy foils was investigated in a small membrane reactor constructed during the first year of the project. The effect of temperature on the hydrogen flux through pure Pd, Pd{sub 60}Cu{sub 40} and Pd{sub 75}Ag{sub 25} alloy membranes, each 25 {micro}m thick, was evaluated in the temperature range from 250 C to 500 C at upstream pressure of 4.4 atm and permeate

  5. Nearby Clumpy, Gas Rich, Star Forming Galaxies: Local Analogs of High Redshift Clumpy Galaxies

    CERN Document Server

    Garland, C A; Mac Low, M -M; Kreckel, K; Rabidoux, K; Guzmán, R

    2015-01-01

    Luminous compact blue galaxies (LCBGs) have enhanced star formation rates and compact morphologies. We combine Sloan Digital Sky Survey data with HI data of 29 LCBGs at redshift z~0 to understand their nature. We find that local LCBGs have high atomic gas fractions (~50%) and star formation rates per stellar mass consistent with some high redshift star forming galaxies. Many local LCBGs also have clumpy morphologies, with clumps distributed across their disks. Although rare, these galaxies appear to be similar to the clumpy star forming galaxies commonly observed at z~1-3. Local LCBGs separate into three groups: 1. Interacting galaxies (~20%); 2. Clumpy spirals (~40%); 3. Non-clumpy, non-spirals with regular shapes and smaller effective radii and stellar masses (~40%). It seems that the method of building up a high gas fraction, which then triggers star formation, is not the same for all local LCBGs. This may lead to a dichotomy in galaxy characteristics. We consider possible gas delivery scenarios and sugges...

  6. The Baryon Cycle of Dwarf Galaxies: Dark, Bursty, Gas-Rich Polluters

    CERN Document Server

    Shen, Sijing; Conroy, Charlie; Governato, Fabio; Mayer, Lucio

    2013-01-01

    We present results from a fully cosmological, very high-resolution, LCDM "zoom-in" simulation of a group of seven field dwarf galaxies with present-day virial masses in the range M_vir=4.4e8-3.6e10 Msun. The simulation includes a blastwave scheme for supernova feedback, a star formation recipe based on a high gas density threshold, metal-dependent radiative cooling, a scheme for the turbulent diffusion of metals and thermal energy, and a uniform UV background that modifies the ionization and excitation state of the gas. The properties of the simulated dwarfs are strongly modulated by the depth of the gravitational potential well. All three halos with M_vir 1e9 Msun dwarfs have blue colors, low star formation efficiencies, high cold gas to stellar mass ratios, and low stellar metallicities. Their bursty star formation histories are characterized by peak specific star formation rates in excess of 50-100 1/Gyr, far outside the realm of normal, more massive galaxies, and in agreement with observations of extreme...

  7. A NEW PATHWAY OF GAS-TO-LIQUID CONVERSION USING CATALYTIC DIELECTRIC-BARRIER DISCHARGE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    IntroductionThe utilianion of methane is very importal to keepthe safe and reliable enemy supply in the new centory.The direct liquid fuel synthesis from methane,however, is thermodynamically not allowed. Theindustrialized synthetic fuel production from methaneclaims a multi-step process. First, the syngas (CasH2)is produced by the steam reforming of methane orpartial oxidation of methane. The liquid fuel is thenproduced from syngas:There exist some difficulties in such utilization ofmethane. First, reactio...

  8. Remarkably enhanced density and specific activity of active sites in Al-rich Cu-, Fe- and Co-beta zeolites for selective catalytic reduction of NOx

    Czech Academy of Sciences Publication Activity Database

    Sazama, Petr; Pilař, Radim; Mokrzycki, Lukasz; Vondrová, Alena; Kaucký, Dalibor; Plšek, Jan; Sklenák, Štěpán; Šťastný, Petr; Klein, Petr

    2016-01-01

    Roč. 189, JUL 2016 (2016), s. 65-74. ISSN 0926-3373 R&D Projects: GA TA ČR(CZ) TH01021259 Institutional support: RVO:61388955 Keywords : SCR -NOx * Al-rich beta zeolite (*BEA) * Cobalt Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 7.435, year: 2014

  9. Catalytic oxidation for treatment of ECLSS and PMMS waste streams. [Process Material Management Systems

    Science.gov (United States)

    Akse, James R.; Thompson, John; Scott, Bryan; Jolly, Clifford; Carter, Donald L.

    1992-01-01

    Catalytic oxidation was added to the baseline multifiltration technology for use on the Space Station Freedom in order to convert low-molecular weight organic waste components such as alcohols, aldehydes, ketones, amides, and thiocarbamides to CO2 at low temperature (121 C), thereby reducing the total organic carbon (TOC) to below 500 ppb. The rate of reaction for the catalytic oxidation of aqueous organics to CO2 and water depends primarily upon the catalyst, temperature, and concentration of reactants. This paper describes a kinetic study conducted to determine the impact of each of these parameters upon the reaction rate. The results indicate that a classic kinetic model, the Langmuir-Hinshelwood rate equation for heterogeneous catalysis, can accurately represent the functional dependencies of this rate.

  10. Research of Hydrogen Preparation with Catalytic Steam-Carbon Reaction Driven by Photo-Thermochemistry Process

    Directory of Open Access Journals (Sweden)

    Xiaoqing Zhang

    2013-01-01

    Full Text Available An experiment of hydrogen preparation from steam-carbon reaction catalyzed by K2CO3 was carried out at 700°C, which was driven by the solar reaction system simulated with Xenon lamp. It can be found that the rate of reaction with catalyst is 10 times more than that without catalyst. However, for the catalytic reaction, there is no obvious change for the rate of hydrogen generation with catalyst content range from 10% to 20%. Besides, the conversion efficiency of solar energy to chemical energy is more than 13.1% over that by photovoltaic-electrolysis route. An analysis to the mechanism of catalytic steam-carbon reaction with K2CO3 is given, and an explanation to the nonbalanced [H2]/[CO + 2CO2] is presented, which is a phenomenon usually observed in experiment.

  11. Partial control of complex chemical processes I. Control of fluidized catalytic cracker

    International Nuclear Information System (INIS)

    A detailed dynamic model of a fluidized catalytic cracker has been developed that allows evaluation of the impact of different designs, control configurations, catalyst and feed composition and control strategies on the control of a fluid cracker. The present paper deals with the existence and the topology of multiple steady states. It is shown that in some cases five steady states can exist. Further, some of these can be close together in terms of the input operating space. Present trends in operating conditions (higher regenerator temperatures and higher catalyst activities) increase the likelihood that desirable operating conditions are in the regions where such multiplicities occur. It is shown that catalytic combustion promoters can eliminate or reduce this problem. The paper also shows that conventional control structures can lead to input multiplicities and that the choice of additional control variables in the primary matrix should depend on operating conditions

  12. Catalytic Effect of Tungsten on Anaerobic Digestion Process for Biogas Production from Fruit and Vegetable Wastes

    OpenAIRE

    Das A; Mondal.C

    2013-01-01

    In the recent years global energy crisis increased at a fast pace. Demand for the use of fossil fuels for cooking and other commercial activities increased along with the increasing population of India. Use of renewable sources of energy viz. biogas for cooking etc can somewhat be an alternative for the excessive demand of fossil fuels like LPG. In this study, the catalytic effect of tungsten for maximizing biogas have been presented. Essentially, anaerobic digesti...

  13. The influence of carbon material properties on the efficiency of catalytic wet peroxide oxidation processes

    OpenAIRE

    Gomes, Helder; R. Ribeiro; Silva, Adrián; Figueiredo, José; Faria, Joaquim

    2015-01-01

    Carbon materiais are well known catalysts for activatin§ H^O^ into hydroxyl radicais (HO'), which are efficient oxidizin § agents. By making use of highly reactive HO" radicais, the elimination of organic compounds can be accomplished by catalytic wet peroxide oxidation (CWPO), a water treatment technology operating under mild conditions of pressure and temperature that hás gained importance due to the decreasing cost of H;0; and its increasing use in wastewater treatm...

  14. Catalyst support materials for prominent mineralization of bisphenol A in catalytic ozonation process.

    Science.gov (United States)

    Cotman, Magda; Erjavec, Boštjan; Djinović, Petar; Pintar, Albin

    2016-05-01

    Degradation of aqueous solution of bisphenol A (BPA) has been investigated through non-catalytic and catalytic ozonation treatments conducted in a semi-batch reactor. Non-catalytic ozonation resulted in complete degradation of aqueous BPA in less than 3 min but did not completely convert the reaction intermediates of BPA ozonation into CO2 and H2O. The main goal of this study was to find an effective heterogeneous catalyst to increase the extent of BPA mineralization at different pH conditions. In this way, the most promising catalyst carrier was γ-Al2O3; at pH = 8.0, 68 % of total organic carbon (TOC) was removed in the period of 75 min, out of which 42 % was attributed to mineralization. Finally, 3.0 wt.% Ru/γ-Al2O3 catalyst exhibited over 82 % of TOC removal after 240 min of ozonation at pH = 5.9, of which 56 % was mineralized. PMID:26880522

  15. Hydrogen production with short contact time. Catalytic partial oxidation of hydrocarbons and oxygenated compounds: Recent advances in pilot- and bench-scale testing and process design

    Energy Technology Data Exchange (ETDEWEB)

    Guarinoni, A.; Ponzo, R.; Basini, L. [ENI Refining and Marketing Div., San Donato Milanese (Italy)

    2010-12-30

    ENI R and D has been active for fifteen years in the development of Short Contact Time - Catalytic Partial Oxidation (SCT-CPO) technologies for producing Hydrogen/Synthesis Gas. From the beginning the experimental work addressed either at defining the fundamental principles or the technical and economical potential of the technology. Good experimental responses, technical solutions' simplicity and flexibility, favourable techno-economical evaluations promoted the progressive widening of the field of the investigations. From Natural Gas (NG) the range of ''processable'' Hydrocarbons extended to Liquefied Petroleum Gas (LPG) and Gasoils, including those characterised by high levels of unsaturated and sulphurated molecules and, lately, to other compounds with biological origin. The extensive work led to the definition of different technological solutions, grouped as follows: Technology 1: Air Blown SCT-CPO of Gaseous Hydrocarbons and/or Light Compounds with biological origin Technology 2: Enriched Air/Oxygen Blown SCT-CPO of Gaseous Hydrocarbons and/or Light Compounds with biological origin Technology 3: Enriched Air/Oxygen Blown SCT-CPO of Liquid Hydrocarbons and/or Compounds with biological origin Recently, the licence rights on a non-exclusive basis for the commercialisation of SCT-CPO based processes for H{sub 2}/Synthesis gas production from light hydrocarbons with production capacity lower than 5,000 Nm{sup 3}/h of H{sub 2} or 7,500 Nm3/h of syngas have been assigned to two external companies. In parallel, development of medium- and large-scale plant solutions is progressing within the ENI group framework. These last activities are addressed to the utilisation of SCT-CPO for matching the variable Hydrogen demand in several contexts of oil refining operation. This paper will report on the current status of SCT-CPO with a focus on experimental results obtained, either at pilot- and bench- scale level. (orig.)

  16. A computational study of the glycine-rich loop of mitochondrial processing peptidase.

    Directory of Open Access Journals (Sweden)

    Tomáš Kučera

    Full Text Available An all atomic, non-restrained molecular dynamics (MD simulation in explicit water was used to study in detail the structural features of the highly conserved glycine-rich loop (GRL of the α-subunit of the yeast mitochondrial processing peptidase (MPP and its importance for the tertiary and quaternary conformation of MPP. Wild-type and GRL-deleted MPP structures were studied using non-restrained MD simulations, both in the presence and the absence of a substrate in the peptidase active site. Targeted MD simulations were employed to study the mechanism of substrate translocation from the GRL to the active site. We demonstrate that the natural conformational flexibility of the GRL is crucial for the substrate translocation process from outside the enzyme towards the MPP active site. We show that the α-helical conformation of the substrate is important not only during its initial interaction with MPP (i.e. substrate recognition, but also later, at least during the first third of the substrate translocation trajectory. Further, we show that the substrate remains in contact with the GRL during the whole first half of the translocation trajectory and that hydrophobic interactions play a major role. Finally, we conclude that the GRL acts as a precisely balanced structural element, holding the MPP subunits in a partially closed conformation regardless the presence or absence of a substrate in the active site.

  17. Evaluation of long-term sulfide oxidation processes within pyrrhotite-rich tailings, Lynn Lake, Manitoba.

    Science.gov (United States)

    Gunsinger, M R; Ptacek, C J; Blowes, D W; Jambor, J L

    2006-02-10

    Oxidation reactions have depleted sulfide minerals in the shallow tailings and have generated sulfate- and metal-rich pore water throughout the East Tailings Management Area (ETMA) at Lynn Lake, Manitoba, Canada. Information concerning the tailings geochemistry and mineralogy suggest the sulfide oxidation processes have reached an advanced stage in the area proximal to the point of tailings discharge. In contrast, the distal tailings, or slimes area, have a higher moisture content close to the impoundment surface, thereby impeding the ingress of oxygen and limiting sulfide oxidation. Numerical modelling of sulfide oxidation indicates the maximum rate of release for sulfate, Fe, and Ni occurred shortly after tailings deposition ceased. Although the sulfide minerals have been depleted in the very shallow tailings, the modelling suggests that sulfide oxidation will continue for hundreds and possibly thousands of years. The combination of sulfide minerals, principally pyrrhotite, that is susceptible to weathering processes and the relatively dry, coarse-grained nature of the tailings have resulted in the formation of a massive-hardpan layer in the proximal area of the ETMA. Because extensive accumulations of secondary oxyhydroxides of ferric iron are already present, remediation strategies for the ETMA should focus on mitigating the release of sulfide oxidation products rather than on preventing further oxidation. PMID:16406605

  18. Monopropellant engine investigation for space shuttle reaction control. Volume 2: Design, fabrication, and demonstration test of a catalytic gas generator for the space shuttle APU

    Science.gov (United States)

    1975-01-01

    The capability of a catalytic gas generator to meet the requirement specified for the space shuttle APU is established. A full-scale gas generator, designed to operate at a chamber pressure of 750 psia and a flow rate of 0.36 lbm/sec, was fabricated and subjected to three separate life test series. The nickel foam metal used for catalyst retention was investigated. Inspection of the foam metal following the first life test revealed significant degradation. Consequently an investigation was conducted to determine the mechanism of degradation and to provide an improved foam metal.

  19. Technology Roadmap: Energy and GHG reductions in the chemical industry via catalytic processes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-06-01

    The chemical industry is a large energy user; but chemical products and technologies also are used in a wide array of energy saving and/or renewable energy applications so the industry has also an energy saving role. The chemical and petrochemical sector is by far the largest industrial energy user, accounting for roughly 10% of total worldwide final energy demand and 7% of global GHG emissions. The International Council of Chemical Associations (ICCA) has partnered with the IEA and DECHEMA (Society for Chemical Engineering and Biotechnology) to describe the path toward further improvements in energy efficiency and GHG reductions in the chemical sector. The roadmap looks at measures needed from the chemical industry, policymakers, investors and academia to press on with catalysis technology and unleash its potential around the globe. The report uncovers findings and best practice opportunities that illustrate how continuous improvements and breakthrough technology options can cut energy use and bring down greenhouse gas (GHG) emission rates. Around 90% of chemical processes involve the use of catalysts – such as added substances that increase the rate of reaction without being consumed by it – and related processes to enhance production efficiency and reduce energy use, thereby curtailing GHG emission levels. This work shows an energy savings potential approaching 13 exajoules (EJ) by 2050 – equivalent to the current annual primary energy use of Germany.

  20. The baryon cycle of dwarf galaxies: dark, bursty, gas-rich polluters

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Sijing; Madau, Piero; Conroy, Charlie [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Governato, Fabio [Astronomy Department, University of Washington, Seattle, WA 98195 (United States); Mayer, Lucio [Institute of Theoretical Physics, University of Zurich, Winterthurerstrasse 190, CH-9057 Zurich (Switzerland)

    2014-09-10

    We present results from a fully cosmological, very high-resolution, ΛCDM simulation of a group of seven field dwarf galaxies with present-day virial masses in the range M {sub vir} = 4.4 × 10{sup 8}-3.6 × 10{sup 10} M {sub ☉}. The simulation includes a blastwave scheme for supernova feedback, a star-formation recipe based on a high gas density threshold, metal-dependent radiative cooling, a scheme for the turbulent diffusion of metals and thermal energy, and a uniform UV background. The properties of the simulated dwarfs are strongly modulated by the depth of the gravitational potential well. All three halos with M {sub vir} < 10{sup 9} M {sub ☉} are devoid of stars, as they never reach the density threshold for star formation of 100 atoms cm{sup –3}. The other four, M {sub vir} > 10{sup 9} M {sub ☉} dwarfs have blue colors, low star-formation efficiencies, high cold gas-to-stellar mass ratios, and low stellar metallicities. Their bursty star-formation histories are characterized by peak specific star-formation rates in excess of 50-100 Gyr{sup –1}, far outside the realm of normal, more massive galaxies. The median stellar age of the simulated galaxies decreases with decreasing halo mass, with the two M {sub vir} ≅ 2-3 × 10{sup 9} M {sub ☉} dwarfs being predominantly young, and the two more massive systems hosting intermediate and older populations. The cosmologically young dwarfs are lit up by tidal interactions, have compact morphologies, and have metallicities and cold gas fractions similar to the relatively quiescent, extremely metal-deficient dwarf population. Metal-enriched galactic outflows produce sub-solar effective yields and pollute with heavy elements a megaparsec-size region of the intergalactic medium, but are not sufficient to completely quench star-formation activity and are absent in the faintest dwarfs.

  1. VHMPID RICH prototype using pressurized C{sub 4}F{sub 8}O radiator gas and VUV photon detector

    Energy Technology Data Exchange (ETDEWEB)

    Acconcia, T.V. [UNICAMP, University of Campinas, Campinas (Brazil); Agócs, A.G. [Wigner RCP of the HAS, Budapest (Hungary); Barile, F. [INFN Sezione di Bari and Universitá degli Studi di Bari, Dipartimento Interateneo di Fisica M. Merlin, Bari (Italy); Barnaföldi, G.G. [Wigner RCP of the HAS, Budapest (Hungary); Bellwied, R. [University of Houston, Houston (United States); Bencédi, G. [Wigner RCP of the HAS, Budapest (Hungary); Bencze, G., E-mail: Gyorgy.Bencze@cern.ch [Wigner RCP of the HAS, Budapest (Hungary); Berényi, D.; Boldizsár, L. [Wigner RCP of the HAS, Budapest (Hungary); Chattopadhyay, S. [Saha Institute, Kolkata (India); Chinellato, D.D. [University of Houston, Houston (United States); Cindolo, F. [University of Salerno, Salerno (Italy); Cossyleon, K. [Chicago State University, Chicago, IL (United States); Das, D.; Das, K.; Das-Bose, L. [Saha Institute, Kolkata (India); Dash, A.K. [UNICAMP, University of Campinas, Campinas (Brazil); D' Ambrosio, S. [University of Salerno, Salerno (Italy); De Cataldo, G. [INFN Sezione di Bari and Universitá degli Studi di Bari, Dipartimento Interateneo di Fisica M. Merlin, Bari (Italy); De Pasquale, S. [University of Salerno, Salerno (Italy); and others

    2014-12-11

    A small-size prototype of a new Ring Imaging Cherenkov (RICH) detector using for the first time pressurized C4F8O radiator gas and a photon detector consisting of MWPC equipped with a CsI photocathode has been built and tested at the PS accelerator at CERN. It contained all the functional elements of the detector proposed as Very High Momentum Particle Identification (VHMPID) upgrade for the ALICE experiment at LHC to provide charged hadron track-by-track identification in the momentum range starting from 5 potentially up to 25 GeV/c. In the paper the equipment and its elements are described and some characteristic test results are shown.

  2. Hydrogen Production by Thermo-catalytic Decomposition of Natural Gas: Carbonaceous Catalysts

    International Nuclear Information System (INIS)

    TCD of CH4 using different kinds of carbon catalyst, activated carbons (AC) and carbon blacks (CB) have been studied. AC showed an acceptable initial reaction rate but they become rapidly deactivated, while CB with high surface area provided more stable and sustainable hydrogen production. Regeneration of the carbonaceous catalysts after deactivation, using CO2 as activating agent has been studied. A commercial active carbon has been selected for the regeneration tests. The optimum operation conditions for the catalysts regeneration have been studied, attending to the burn off of the catalysts during the regeneration, which is important for the self-consistence of the process, and the recovering in the surface area, which is one of the most important factors affecting the activity of these catalysts. (authors)

  3. Sulfur and Iron Speciation in Gas-rich Impact-melt Glasses from Basaltic Shergottites Determined by Microxanes

    Science.gov (United States)

    Sutton, S. R.; Rao, M. N.; Nyquist, L. E.

    2008-01-01

    Sulfur is abundantly present as sulfate near Martian surface based on chemical and mineralogical investigations on soils and rocks in Viking, Pathfinder and MER missions. Jarosite is identified by Mossbauer studies on rocks at Meridian and Gusev, whereas MgSO4 is deduced from MgO - SO3 correlations in Pathfinder MER and Viking soils. Other sulfate minerals such as gypsum and alunogen/ S-rich aluminosilicates and halides are detected only in martian meteorites such as shergottites and nakhlites using SEM/FE-SEM and EMPA techniques. Because sulfur has the capacity to occur in multiple valence states, determination of sulfur speciation (sulfide/ sulfate) in secondary mineral assemblages in soils and rocks near Mars surface may help us understand whether the fluid-rock interactions occurred under oxidizing or reducing conditions. To understand the implications of these observations for the formation of the Gas-rich Impact-melt (GRIM) glasses, we determined the oxidation state of Fe in the GRIM glasses using Fe K micro-XANES techniques.

  4. Experimental and numerical investigation of the catalytic partial oxidation of methane to synthesis gas for power generation applications[Dissertation 17183

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, A.

    2007-07-01

    The present work addresses the catalytic partial oxidation (CPO) of methane to synthesis gas, with particular emphasis on power generation applications. A combined experimental and numerical investigation of methane partial oxidation to synthesis gas (H{sub 2}, CO) over rhodium-based catalysts has been carried out at pressures of up to 10 bar. The reactivity of the produced hydrogen and the suitably-low light-off temperatures of the CPO reactor, greatly facilitate operation of power generation gas turbines with reduced NO{sub x} emissions, stable operation with low calorific value fuels, and new combustion strategies for efficient CO{sub 2} capture. Those strategies utilize CPO of methane with oxygen (separated from air) and large exhaust gas recycle (H{sub 2}O and CO{sub 2}). An optically accessible catalytic channel-flow reactor was used to carry out Raman spectroscopy of major gas-phase species and laser induced fluorescence (LIF) of formaldehyde, in order to gain fundamental information on the catalytic and gas-phase chemical pathways. Transverse concentration profiles measured by the spontaneous Raman scattering technique determined the catalytic reactivity, while the LIF provided flame shapes and anchoring positions that, in turn, characterized the gaseous reactivity. Comparison between measurements and 2-D CFD computations, led to the validation of detailed catalytic and gas-phase reaction mechanisms. Experiments in a subscale gas-turbine honeycomb catalytic reactor have shown that the foregoing reaction mechanisms were also appropriate under gas-turbine relevant conditions with short reactant residence times. The light-off behavior of the subscale honeycomb reactor was reproduced by transient 2-D CFD computations. Ignition and extinction in CPO was studied. It was shown that, despite the chemical impact of the H{sub 2}O diluent during the transient catalytic ignition event, the light-off times themselves were largely unaffected by the exhaust gas dilution

  5. Project Safe. Gas related processes in SFR

    International Nuclear Information System (INIS)

    The radionuclide release from the SFR repository caused by gas generation was calculated for different scenarios for three repository parts (Silo, BMA and 1BTF). The calculation cases are based on the way the gas escapes from the concrete structures. In the basic cases the gas escapes through the evacuation pipes in the concrete lid of the Silo, through existing gaps between the concrete walls and the lid in BMA, and through the concrete backfill surrounding the waste packages in 1BTF. These cases correspond to the situation that we expect to occur. Another category of cases corresponds to the situation where an initial fracture exists in the concrete structures. The fracture is assumed to exist at the bottom of the respective concrete structure in the Silo and BMA. For 1BTF the initial defect is represented by a fracture transversely crossing the section containing the steel drums with ashes. Other cases were also calculated with the purpose of studying some special situations. For example, the consequences of a silo repository without evacuation pipes and backfill in the interior of BMA. The radionuclide release, for some radionuclides, may be increased by several orders of magnitude when contaminated water is expelled by gas from the interior of the concrete structures. However, the impact on the total doses during the first thousands years after closure of the repository is limited. The total dose is dominated by the release of organic 14C. Since the radionuclides are released to the coastal area during the first thousand years the dilution is considerable, which results in a very low dose

  6. Project Safe. Gas related processes in SFR

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, L. [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Chemical Engineering; Skagius, K.; Soedergren, S.; Wiborgh, M. [Kemakta Konsult AB, Stockholm (Sweden)

    2001-06-01

    The radionuclide release from the SFR repository caused by gas generation was calculated for different scenarios for three repository parts (Silo, BMA and 1BTF). The calculation cases are based on the way the gas escapes from the concrete structures. In the basic cases the gas escapes through the evacuation pipes in the concrete lid of the Silo, through existing gaps between the concrete walls and the lid in BMA, and through the concrete backfill surrounding the waste packages in 1BTF. These cases correspond to the situation that we expect to occur. Another category of cases corresponds to the situation where an initial fracture exists in the concrete structures. The fracture is assumed to exist at the bottom of the respective concrete structure in the Silo and BMA. For 1BTF the initial defect is represented by a fracture transversely crossing the section containing the steel drums with ashes. Other cases were also calculated with the purpose of studying some special situations. For example, the consequences of a silo repository without evacuation pipes and backfill in the interior of BMA. The radionuclide release, for some radionuclides, may be increased by several orders of magnitude when contaminated water is expelled by gas from the interior of the concrete structures. However, the impact on the total doses during the first thousands years after closure of the repository is limited. The total dose is dominated by the release of organic {sup 14}C. Since the radionuclides are released to the coastal area during the first thousand years the dilution is considerable, which results in a very low dose.

  7. Liquid and Gaseous Fuel from Waste Plastics by Sequential Pyrolysis and Catalytic Reforming Processes over Indonesian Natural Zeolite Catalysts

    Directory of Open Access Journals (Sweden)

    Mochamad Syamsiro

    2014-08-01

    Full Text Available In this study, the performance of several differently treated natural zeolites in a sequential pyrolysis and catalytic reforming of plastic materials i.e. polypropylene (PP and polystyrene (PS were investigated. The experiments were carried out on two stage reactor using semi-batch system. The samples were degraded at 500°C in the pyrolysis reactor and then reformed at 450°C in the catalytic reformer. The results show that the mordenite-type natural zeolites could be used as efficient catalysts for the conversion of PP and PS into liquid and gaseous fuel. The treatment of natural zeolites in HCl solution showed an increase of the surface area and the Si/Al ratio while nickel impregnation increased the activity of catalyst. As a result, liquid product was reduced while gaseous product was increased. For PP, the fraction of gasoline (C5-C12 increased in the presence of catalysts. Natural zeolite catalysts could also be used to decrease the heavy oil fraction (>C20. The gaseous products were found that propene was dominated in all conditions. For PS, propane and propene were the main components of gases in the presence of nickel impregnated natural zeolite catalyst. Propene was dominated in pyrolysis over natural zeolite catalyst. The high quality of gaseous product can be used as a fuel either for driving gas engines or for dual-fuel diesel engine.

  8. Process and system for removing impurities from a gas

    Energy Technology Data Exchange (ETDEWEB)

    Henningsen, Gunnar; Knowlton, Teddy Merrill; Findlay, John George; Schlather, Jerry Neal; Turk, Brian S

    2014-04-15

    A fluidized reactor system for removing impurities from a gas and an associated process are provided. The system includes a fluidized absorber for contacting a feed gas with a sorbent stream to reduce the impurity content of the feed gas; a fluidized solids regenerator for contacting an impurity loaded sorbent stream with a regeneration gas to reduce the impurity content of the sorbent stream; a first non-mechanical gas seal forming solids transfer device adapted to receive an impurity loaded sorbent stream from the absorber and transport the impurity loaded sorbent stream to the regenerator at a controllable flow rate in response to an aeration gas; and a second non-mechanical gas seal forming solids transfer device adapted to receive a sorbent stream of reduced impurity content from the regenerator and transfer the sorbent stream of reduced impurity content to the absorber without changing the flow rate of the sorbent stream.

  9. 天然气低碳催化燃烧烤箱的应用及烟气对大气的影响%Research on Application of Low Carbon Catalytic Combustion Oven by Natural Gas and Influence of its Exhaust Gas to Atmosphere

    Institute of Scientific and Technical Information of China (English)

    张世红; 何繁; 房凯; 于哲

    2015-01-01

    Catalytic combustion is a new type of combustion which oxidized natural gas completely with high combustion efficiency, near_zero pollutant emissions. They were environmentally friendly energy_saving combustion devices. The experiment of roasted meat inside catalytic combustion oven V is discussed in the paper in order to verify the feasibility of the application of catalytic combustion technology in the food processing of meat. The finished product was analyzed from the catalytic combustion oven. Such as roasted duck, the result of experiment shows generally that saving energy and environmental protection by catalytic combustion oven for roasted food are better than that of conventional oven. There is distinguishing feature about the taste and quality of the roasted duck by catalytic combustion oven.%天然气催化燃烧是一种新型的燃烧方式,具有天然气燃烧完全、燃烧效率高、近零污染物排放等优点,是一种环保节能的燃烧方式。利用催化燃烧V型烤箱进行肉食加工的应用实验,验证关于催化燃烧技术在肉类食品加工方面的应用可行性,并对催化燃烧烧制出的成品进行分析。以烤鸭为例,综合说明利用催化燃烧烤箱烧制的肉类食品比传统烧制方法更节能环保,并且在口感和质量上比传统方法烧制的烤鸭更有特色。

  10. Constructing wetlands: measuring and modeling feedbacks of oxidation processes between plants and clay-rich material

    Science.gov (United States)

    Saaltink, Rémon; Dekker, Stefan C.; Griffioen, Jasper; Wassen, Martin J.

    2016-04-01

    Interest is growing in using soft sediment as a building material in eco-engineering projects. Wetland construction in the Dutch lake Markermeer is an example: here the option of dredging some of the clay-rich lake-bed sediment and using it to construct 10.000 ha of wetland will soon go under construction. Natural processes will be utilized during and after construction to accelerate ecosystem development. Knowing that plants can eco-engineer their environment via positive or negative biogeochemical plant-soil feedbacks, we conducted a six-month greenhouse experiment to identify the key biogeochemical processes in the mud when Phragmites australis is used as an eco-engineering species. We applied inverse biogeochemical modeling to link observed changes in pore water composition to biogeochemical processes. Two months after transplantation we observed reduced plant growth and shriveling as well as yellowing of foliage. The N:P ratios of plant tissue were low and were affected not by hampered uptake of N but by enhanced uptake of P. Plant analyses revealed high Fe concentrations in the leaves and roots. Sulfate concentrations rose drastically in our experiment due to pyrite oxidation; as reduction of sulfate will decouple Fe-P in reducing conditions, we argue that plant-induced iron toxicity hampered plant growth, forming a negative feedback loop, while simultaneously there was a positive feedback loop, as iron toxicity promotes P mobilization as a result of reduced conditions through root death, thereby stimulating plant growth and regeneration. Given these two feedback mechanisms, we propose that when building wetlands from these mud deposits Fe-tolerant species are used rather than species that thrive in N-limited conditions. The results presented in this study demonstrate the importance of studying the biogeochemical properties of the building material and the feedback mechanisms between plant and soil prior to finalizing the design of the eco-engineering project.

  11. Gas-rich mergers and feedback are ubiqitous amongst starbursting radio galaxies, as revealed by JVLA, IRAM PdBI and Herschel

    CERN Document Server

    Ivison, R J; Amblard, A; Arumugam, V; De Breuck, C; Emonts, B H C; Feain, I; Greve, T R; Haas, M; Ibar, E; Jarvis, M J; Kovaks, A; Lehnert, M D; Nesvadba, N P H; Rottgering, H J A; Seymour, N; Wylezalek, D

    2012-01-01

    We report new, sensitive observations of two z ~ 3-3.5 FIR-luminous radio galaxies, 6C1909+72 and B3J2330+3927, in 12CO J=1-0 with the Karl Jansky VLA and at 100-500um using Herschel, alongside new and archival 12CO J=4-3 observations from IRAM PdBI. We introduce a new colour-colour diagnostic plot to constrain the redshifts of several distant, dusty galaxies in our target fields. A bright SMG near 6C1909+72 likely shares the same node or filament as the signpost AGN, but it is not detected in CO despite ~20,000 km/s of velocity coverage. Also in the 6C1909+72 field, a large, red dust feature spanning ~500 kpc is aligned with the radio jet. We suggest several processes by which metal-rich material may have been transported, favouring a collimated outflow reminiscent of the jet-oriented metal enrichment seen in local cluster environments. Our interferometric imaging reveals a gas-rich companion to B3J2330+3927; indeed, all bar one of the eight z >~ 2 radio galaxies (or companions) detected in CO provide some e...

  12. A new continuous-flow process for catalytic conversion of glycerol to oxygenated fuel additive: Catalyst screening

    International Nuclear Information System (INIS)

    Highlights: • A continuous-flow process for catalytic synthesis of solketal from glycerol. • Six different heterogeneous acid catalysts were studied in the process. • Glycerol conversion and solketal yield of 90% and 88% respectively were achieved. • The process has the potential to be scaled-up for industrial applications. - Abstract: A new continuous-flow reactor was designed for the conversion of glycerol to solketal, an oxygenated fuel additive, through ketalization with acetone. Six heterogeneous catalysts were investigated with respect to their catalytic activity and stability in a flow reactor. The acidity of the catalysts positively influences the catalyst’s activity. Among all the solid acid catalysts tested, the maximum solketal yield from experiments at 40 °C, 600 psi and WHSV of 4 h−1 attained 73% and 88% at the acetone/glycerol molar ratio of 2.0 and 6.0, respectively, with Amberlyst Wet. Based on the solketal yield and glycerol conversion results, the activity of all catalysts tested follows the following order of sequence: Amberlyst Wet ≈ Zeolite ≈ Amberlyst Dry > Zirconium Sulfate > Montmorillonite > Polymax. An increase in acetone/glycerol molar ratio or a decrease in WHSV enhanced the glycerol conversion as expected. This process offers an attractive route for converting glycerol, the main by-product of biodiesel, to solketal – a value-added green product with potential industrial applications as a valuable fuel additive or combustion promoter for gasoline engines

  13. An evaluation of Substitute natural gas production from different coal gasification processes based on modeling

    International Nuclear Information System (INIS)

    Coal and lignite will play a significant role in the future energy production. However, the technical options for the reduction of CO2 emissions will define the extent of their share in the future energy mix. The production of synthetic or substitute natural gas (SNG) from solid fossil fuels seems to be a very attractive process: coal and lignite can be upgraded into a methane rich gas which can be transported and further used in high efficient power systems coupled with CO2 sequestration technologies. The aim of this paper is to present a modeling analysis comparison between substitute natural gas production from coal by means of allothermal steam gasification and autothermal oxygen gasification. In order to produce SNG from syngas several unit operations are required such as syngas cooling, cleaning, potential compression and, of course, methanation reactors. Finally the gas which is produced has to be conditioned i.e. removal of unwanted species, such as CO2 etc. The heat recovered from the overall process is utilized by a steam cycle, producing power. These processes were modeled with the computer software IPSEpro™. An energetic and exergetic analysis of the coal to SNG processes have been realized and compared. -- Highlights: ► The production of SNG from coal is examined. ► The components of the process were simulated for integrated autothermal or allothermal coal gasification to SNG. ► The energetic and exergetic evaluation of the two processes is presented.

  14. ALFALFA DISCOVERY OF THE NEARBY GAS-RICH DWARF GALAXY LEO P. II. OPTICAL IMAGING OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Rhode, Katherine L.; Salzer, John J.; Haurberg, Nathalie C.; Van Sistine, Angela; Young, Michael D. [Department of Astronomy, Indiana University, 727 East Third Street, Bloomington, IN 47405 (United States); Haynes, Martha P.; Giovanelli, Riccardo; Adams, Elizabeth A. K. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Cannon, John M. [Department of Physics and Astronomy, Macalester College, Saint Paul, MN 55105 (United States); Skillman, Evan D.; McQuinn, Kristen B. W., E-mail: rhode@astro.indiana.edu, E-mail: slaz@astro.indiana.edu, E-mail: riccardo@astro.cornell.edu, E-mail: haynes@astro.cornell.edu, E-mail: betsey@astro.cornell.edu, E-mail: jcannon@macalester.edu, E-mail: skillman@astro.umn.edu, E-mail: kmcquinn@astro.umn.edu [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States)

    2013-06-15

    We present results from ground-based optical imaging of a low-mass dwarf galaxy discovered by the ALFALFA 21 cm H I survey. Broadband (BVR) data obtained with the WIYN 3.5 m telescope at Kitt Peak National Observatory (KPNO) are used to construct color-magnitude diagrams of the galaxy's stellar population down to V{sub o} {approx} 25. We also use narrowband H{alpha} imaging from the KPNO 2.1 m telescope to identify a H II region in the galaxy. We use these data to constrain the distance to the galaxy to be between 1.5 and 2.0 Mpc. This places Leo P within the Local Volume but beyond the Local Group. Its properties are extreme: it is the lowest-mass system known that contains significant amounts of gas and is currently forming stars.

  15. ALFALFA DISCOVERY OF THE NEARBY GAS-RICH DWARF GALAXY LEO P. II. OPTICAL IMAGING OBSERVATIONS

    International Nuclear Information System (INIS)

    We present results from ground-based optical imaging of a low-mass dwarf galaxy discovered by the ALFALFA 21 cm H I survey. Broadband (BVR) data obtained with the WIYN 3.5 m telescope at Kitt Peak National Observatory (KPNO) are used to construct color-magnitude diagrams of the galaxy's stellar population down to Vo ∼ 25. We also use narrowband Hα imaging from the KPNO 2.1 m telescope to identify a H II region in the galaxy. We use these data to constrain the distance to the galaxy to be between 1.5 and 2.0 Mpc. This places Leo P within the Local Volume but beyond the Local Group. Its properties are extreme: it is the lowest-mass system known that contains significant amounts of gas and is currently forming stars.

  16. DISCOVERY OF A GAS-RICH COMPANION TO THE EXTREMELY METAL-POOR GALAXY DDO 68

    International Nuclear Information System (INIS)

    We present H I spectral-line imaging of the extremely metal-poor galaxy DDO 68. This system has a nebular oxygen abundance of only ∼3% Z ☉, making it one of the most metal-deficient galaxies known in the local volume. Surprisingly, DDO 68 is a relatively massive and luminous galaxy for its metal content, making it a significant outlier in the mass-metallicity and luminosity-metallicity relationships. The origin of such a low oxygen abundance in DDO 68 presents a challenge for models of the chemical evolution of galaxies. One possible solution to this problem is the infall of pristine neutral gas, potentially initiated during a gravitational interaction. Using archival H I spectral-line imaging obtained with the Karl G. Jansky Very Large Array, we have discovered a previously unknown companion of DDO 68. This low-mass (MH I = 2.8 × 107 M ☉), recently star-forming (SFRFUV = 1.4 × 10–3 M ☉ yr–1, SFRHα < 7 × 10–5 M ☉ yr–1) companion has the same systemic velocity as DDO 68 (V sys = 506 km s–1; D = 12.74 ± 0.27 Mpc) and is located at a projected distance of ∼42 kpc. New H I maps obtained with the 100 m Robert C. Byrd Green Bank Telescope provide evidence that DDO 68 and this companion are gravitationally interacting at the present time. Low surface brightness H I gas forms a bridge between these objects

  17. DISCOVERY OF A GAS-RICH COMPANION TO THE EXTREMELY METAL-POOR GALAXY DDO 68

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, John M.; Alfvin, Erik D. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Johnson, Megan; Koribalski, Baerbel [Australia Telescope National Facility, CSIRO Astronomy and Space Science, P.O. Box 76, NSW 1710, Epping (Australia); McQuinn, Kristen B. W.; Skillman, Evan D. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Bailin, Jeremy [Department of Physics and Astronomy, University of Alabama, P.O. Box 870324, Tuscaloosa, AL 35487-0324 (United States); Ford, H. Alyson [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States); Girardi, Léo [Osservatorio Astronomico di Padova—INAF, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Hirschauer, Alec S.; Janowiecki, Steven; Salzer, John J.; Van Sistine, Angela [Department of Astronomy, Indiana University, 727 East Third Street, Bloomington, IN 47405 (United States); Dolphin, Andrew [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Elson, E. C. [Astrophysics, Cosmology and Gravity Centre (ACGC), Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Marigo, Paola; Rosenfield, Philip [Dipartimento di Fisica e Astronomia Galileo Galilei, Universitá degli Studi di Padova, Vicolo dell' Osservatorio 3, I-35122 Padova (Italy); Rosenberg, Jessica L. [School of Physics, Astronomy, and Computational Science, George Mason University, Fairfax, VA 22030 (United States); Venkatesan, Aparna [Department of Physics and Astronomy, University of San Francisco, 2130 Fulton Street, San Francisco, CA 94117 (United States); Warren, Steven R., E-mail: jcannon@macalester.edu [Department of Astronomy, University of Maryland, CSS Bldg., Rm. 1024, Stadium Drive, College Park, MD 20742-2421 (United States)

    2014-05-20

    We present H I spectral-line imaging of the extremely metal-poor galaxy DDO 68. This system has a nebular oxygen abundance of only ∼3% Z {sub ☉}, making it one of the most metal-deficient galaxies known in the local volume. Surprisingly, DDO 68 is a relatively massive and luminous galaxy for its metal content, making it a significant outlier in the mass-metallicity and luminosity-metallicity relationships. The origin of such a low oxygen abundance in DDO 68 presents a challenge for models of the chemical evolution of galaxies. One possible solution to this problem is the infall of pristine neutral gas, potentially initiated during a gravitational interaction. Using archival H I spectral-line imaging obtained with the Karl G. Jansky Very Large Array, we have discovered a previously unknown companion of DDO 68. This low-mass (M{sub H} {sub I} = 2.8 × 10{sup 7} M {sub ☉}), recently star-forming (SFR{sub FUV} = 1.4 × 10{sup –3} M {sub ☉} yr{sup –1}, SFR{sub Hα} < 7 × 10{sup –5} M {sub ☉} yr{sup –1}) companion has the same systemic velocity as DDO 68 (V {sub sys} = 506 km s{sup –1}; D = 12.74 ± 0.27 Mpc) and is located at a projected distance of ∼42 kpc. New H I maps obtained with the 100 m Robert C. Byrd Green Bank Telescope provide evidence that DDO 68 and this companion are gravitationally interacting at the present time. Low surface brightness H I gas forms a bridge between these objects.

  18. Comparison of reduction disintegration characteristics of TiO2-rich burdens prepared with sintering process and composite agglomeration process

    Science.gov (United States)

    Yu, Zheng-wei; Li, Guang-hui; Liu, Chen; Zhou, Feng; Peng, Zhi-wei; Jiang, Tao

    2016-04-01

    To reveal the impact of the composite agglomeration process (CAP) on the reduction disintegration properties of TiO2-rich ironmaking burden for a blast furnace, the reduction disintegration indices (RDIs), mineral constituents, and microstructure of the products prepared by the CAP and the traditional sintering process (TSP) were investigated. The results showed that, compared to the sinter with a basicity of 2.0 prepared by the TSP, the RDI+6.3 and the RDI+3.15 of the CAP product with the same basicity increased by 28.2wt% and 13.7wt%, respectively, whereas the RDI-0.5 decreased by 2.7wt%. The analysis of the mineral constituents and microstructure of the products indicated that the decreasing titanohematite content decreased the volume expansion during reduction. Meanwhile, the decreasing perovskite content decreased its detrimental effect on the reduction disintegration properties. In addition, the higher silicoferrite of calcium and aluminum (SFCA) content improved the strength of the CAP product. Together, these factors result in an improvement of the RDI of the CAP products. In addition, compared to the sinter, the reduced CAP products clearly contained fewer cracks, which also led to mitigation of reduction disintegration.

  19. Quantitative Analysis of Trace Chromium in Blood Samples. Combination of the Advanced Oxidation Process with Catalytic Adsorptive Stripping Voltammetry

    OpenAIRE

    Yong, Li; Armstrong, Kristie C.; Dansby-Sparks, Royce N.; Carrington, Nathan A.; Chambers, James Q.; Xue, Zi-Ling

    2006-01-01

    A new method for pretreating blood samples for trace Cr analysis is described. The Advanced Oxidation Process (AOP with H2O2 and 5.5-W irradiation for 60 min) is used to remove biological/organic species for subsequent analysis. Prior to the AOP pretreatment, acid (HNO3) is used at pH 3.0 to inhibit the enzyme catalase in the blood samples. Catalytic Adsorptive Stripping Voltammetry (CAdSV) at a bismuth film electrode (BiFE) gives Cr concentration of 6.0 ± 0.3 ppb in the blood samples. This c...

  20. High specific surface area carbon nanotubes from catalytic chemical vapor deposition process

    OpenAIRE

    Bacsa, Revathi; Laurent, Christophe; Peigney, Alain; Bacsa, Wolfgang; Vaugien, Thibaud; Rousset, Abel

    2000-01-01

    A carbon nanotube specimen with a carbon content of 83 wt.% (95 vol.%) and a specific surface area equal to 790 m2/g (corresponding to 948 m2/g of carbon) is prepared by a catalytic chemical vapor deposition method. The nanotubes, 90% of which are single- and double-walled, are individual rather than in bundles. High-resolution electron microscopy shows a diameter distribution in the range 0.8-5 nm and Raman spectroscopy shows a high proportion of tubular carbon. Both techniques reveal a maxi...

  1. Effects of ferric ions on the catalytic ozonation process on sanitary landfill leachates

    Directory of Open Access Journals (Sweden)

    Messias Borges Silva

    2013-04-01

    Full Text Available Leachates exhibiting an unstable ratio of biochemical oxygen demand (BOD and chemical oxygen demand (COD of approximately 0.45 are typical of new landfills in the City of Cachoeira Paulista, Brazil. Although the organic matter portion is bio-treatable, the presence of refractory leached organic material requires unconventional effluent-treatment processes. Leachate treatment with ozone oxidation, in the presence of ferric ions, acts as catalyst in the formation of hydroxyl radicals. Ozone was obtained by corona-discharge from high-purity O2 gas. The treatment was performed in natura in a jacketed borosilicate glass reactor containing 900 ml of leachate. The analyzed response variable was expressed as the concentration of dissolved organic carbon (DOC. In order to determine the optimal proportions to produce the greatest degradation rate for organic materials, variations in experimental O2 flow-fed to the generator, the Fe(iii concentration, and the output of the ozonator were conducted over two experimental runs. Experimental models showed a DOC degradation on the order of 81.25%.

  2. Commercial Application of the RAR Sulfur Recovery and Tail Gas Treating Process

    Institute of Scientific and Technical Information of China (English)

    Guo Hong; Zhang Songping

    2003-01-01

    The 40kt/a sulfur recovery unit for tail gas treating applying the reduction-absorption-recycling (RAR) technology is aimed at regeneration of the rich amine solution and recovery of sulfur to operate in tandem with the 1.2Mt/a diesel hydrofining unit. The process unit calibration data have revealed that the recovery of total sulfur reaches 99.86%, which is 6.65 percentage points higher than that before application of the RAR technology. The SO2 content in vented tail gas is 0.27 t/d, which is much less than the latest emission standard prescribed by the State. The factors that can affect the unit operation have been analyzed and corresponding measures have been suggested including the necessity to improve the control over the reaction temperature in the tail gas hydrogenation unit.

  3. Catalytic effect of ultrananocrystalline Fe₃O₄ on algal bio-crude production via HTL process.

    Science.gov (United States)

    Rojas-Pérez, Arnulfo; Diaz-Diestra, Daysi; Frias-Flores, Cecilia B; Beltran-Huarac, Juan; Das, K C; Weiner, Brad R; Morell, Gerardo; Díaz-Vázquez, Liz M

    2015-11-14

    We report a comprehensive quantitative study of the production of refined bio-crudes via a controlled hydrothermal liquefaction (HTL) process using Ulva fasciata macroalgae (UFMA) as biomass and ultrananocrystalline Fe3O4 (UNCFO) as catalyst. X-ray diffraction and electron microscopy were applied to elucidate the formation of the high-quality nanocatalysts. Gas chromatography-mass spectroscopy (GC-MS) and CHNS analyses showed that the bio-crude yield and carbon/oxygen ratios increase as the amount of UNCFO increases, reaching a peak value of 32% at 1.25 wt% (a 9% increase when compared to the catalyst-free yield). The bio-crude is mainly composed of fatty acids, alcohols, ketones, phenol and benzene derivatives, and hydrocarbons. Their relative abundance changes as a function of catalyst concentration. FTIR spectroscopy and vibrating sample magnetometry revealed that the as-produced bio-crudes are free of iron species, which accumulate in the generated bio-chars. Our findings also indicate that the energy recovery values via the HTL process are sensitive to the catalyst loading, with a threshold loading of 1.25 wt%. GC-MS studies show that the UNCFO not only influences the chemical nature of the resulting bio-crudes and bio-chars, but also the amount of fixed carbons in the solid residues. The detailed molecular characterization of the bio-crudes and bio-chars catalyzed by UNCFO represents the first systematic study reported using UFMA. This study brings forth new avenues to advance the highly-pure bio-crude production employing active, heterogeneous catalyst materials that are recoverable and recyclable for continuous thermochemical reactions. PMID:26465090

  4. Performance evaluation of an advanced air-fuel ratio controller on a stationary, rich-burn natural gas engine

    Science.gov (United States)

    Kochuparampil, Roshan Joseph

    The advent of an era of abundant natural gas is making it an increasingly economical fuel source against incumbents such as crude oil and coal, in end-use sectors such as power generation, transportation and industrial chemical production, while also offering significant environmental benefits over these incumbents. Equipment manufacturers, in turn, are responding to widespread demand for power plants optimized for operation with natural gas. In several applications such as distributed power generation, gas transmission, and water pumping, stationary, spark-ignited, natural gas fueled internal combustion engines (ICEs) are the power plant of choice (over turbines) owing to their lower equipment and operational costs, higher thermal efficiencies across a wide load range, and the flexibility afforded to end-users when building fine-resolution horsepower topologies: modular size increments ranging from 100 kW -- 2 MW per ICE power plant compared to 2 -- 5 MW per turbine power plant. Under the U.S. Environment Protection Agency's (EPA) New Source Performance Standards (NSPS) and Reciprocating Internal Combustion Engine National Emission Standards for Hazardous Air Pollutants (RICE NESHAP) air quality regulations, these natural gas power plants are required to comply with stringent emission limits, with several states mandating even stricter emissions norms. In the case of rich-burn or stoichiometric natural gas ICEs, very high levels of sustained emissions reduction can be achieved through exhaust after-treatment that utilizes Non Selective Catalyst Reduction (NSCR) systems. The primary operational constraint with these systems is the tight air-fuel ratio (AFR) window of operation that needs to be maintained if the NSCR system is to achieve simultaneous reduction of carbon monoxide (CO), nitrogen oxides (NOx), total hydrocarbons (THC), volatile organic compounds (VOCs), and formaldehyde (CH 2O). Most commercially available AFR controllers utilizing lambda (oxygen

  5. Opportunities in the United States' gas processing industry

    International Nuclear Information System (INIS)

    To keep up with the increasing amount of natural gas that will be required by the market and with the decreasing quality of the gas at the well-head, the gas processing industry must look to new technologies to stay competitive. The Gas Research Institute (GR); is managing a research, development, design and deployment program that is projected to save the industry US dollar 230 million/year in operating and capital costs from gas processing related activities in NGL extraction and recovery, dehydration, acid gas removal/sulfur recovery, and nitrogen rejection. Three technologies are addressed here. Multivariable Control (MVC) technology for predictive process control and optimization is installed or in design at fourteen facilities treating a combined total of over 30x109 normal cubic meter per year (BN m3/y) [1.1x1012 standard cubic feet per year (Tcf/y)]. Simple pay backs are typically under 6 months. A new acid gas removal process based on n-formyl morpholine (NFM) is being field tested that offers 40-50% savings in operating costs and 15-30% savings in capital costs relative to a commercially available physical solvent. The GRI-MemCalcTM Computer Program for Membrane Separations and the GRI-Scavenger CalcBaseTM Computer Program for Scavenging Technologies are screening tools that engineers can use to determine the best practice for treating their gas. (au) 19 refs

  6. 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.

  7. Performance and emissions of a supercharged dual-fuel engine fueled by hydrogen-rich coke oven gas

    Energy Technology Data Exchange (ETDEWEB)

    Roy, M.M.; Tomita, E.; Kawahara, N.; Harada, Y.; Sakane, A. [Okayama University, Okayama (Japan). Dept. of Mechanical Engineering

    2009-12-15

    This study investigated the engine performance and emissions of a supercharged dual-fuel engine fueled by hydrogen-rich coke oven gas and ignited by a pilot amount of diesel fuel. The engine was tested for use as a cogeneration engine, so power output while maintaining a reasonable thermal efficiency was important. Experiments were carried out at a constant pilot injection pressure and pilot quantity for different fuel-air equivalence ratios and at various injection timings without and with exhaust gas recirculation (EGR). The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. The engine was tested first without EGR condition up to the maximum possible fuel-air equivalence ratio of 0.65. A maximum indicated mean effective pressure (IMEP) of 1425 kPa and a thermal efficiency of 39% were obtained. However, the nitrogen oxides (NOx) emissions were high. A simulated EGR up to 50% was then performed to obtain lower NOx emissions. The maximum reduction of NOx was 60% or more maintaining the similar levels of IMEP and thermal efficiency. Two-stage combustion was obtained; this is an indicator of maximum power output conditions and a precursor of knocking combustion.

  8. THE BARYONIC TULLY-FISHER RELATION OF GAS-RICH GALAXIES AS A TEST OF ΛCDM AND MOND

    International Nuclear Information System (INIS)

    The baryonic Tully-Fisher relation (BTFR) is an empirical relation between baryonic mass and rotation velocity in disk galaxies. It provides tests of galaxy formation models in ΛCDM and of alternative theories like modified Newtonian dynamics (MOND). Observations of gas-rich galaxies provide a measure of the slope and normalization of the BTFR that is more accurate (if less precise) than that provided by star-dominated spirals, as their masses are insensitive to the details of stellar population modeling. Recent independent data for such galaxies are consistent with Mb = AV4f with A = 47 ± 6 M☉ km–4 s4. This is equivalent to MOND with a0 = 1.3 ± 0.3 Å s–2. The scatter in the data is consistent with being due entirely to observational uncertainties. It is unclear why the physics of galaxy formation in ΛCDM happens to pick out the relation predicted by MOND. We introduce a feedback efficacy parameter E to relate halo properties to those of the galaxies they host. E correlates with star formation rate and gas fraction in the sense that galaxies that have experienced the least star formation have been most impacted by feedback.

  9. Rich soil carbon and nitrogen but low atmospheric greenhouse gas fluxes from North Sulawesi mangrove swamps in Indonesia.

    Science.gov (United States)

    Chen, Guang C; Ulumuddin, Yaya I; Pramudji, Sastro; Chen, Shun Y; Chen, Bin; Ye, Yong; Ou, Dan Y; Ma, Zhi Y; Huang, Hao; Wang, Jing K

    2014-07-15

    The soil to atmosphere fluxes of greenhouse gases N2O, CH4 and CO2 and their relationships with soil characteristics were investigated in three tropical oceanic mangrove swamps (Teremaal, Likupang and Kema) in North Sulawesi, Indonesia. Mangrove soils in North Sulawesi were rich in organic carbon and nitrogen, but the greenhouse gas fluxes were low in these mangroves. The fluxes ranged -6.05-13.14 μmol m(-2)h(-1), -0.35-0.61 μmol m(-2)h(-1) and -1.34-3.88 mmol m(-2)h(-1) for N2O, CH4 and CO2, respectively. The differences in both N2O and CH4 fluxes among different mangrove swamps and among tidal positions in each mangrove swamp were insignificant. CO2 flux was influenced only by mangrove swamps and the value was higher in Kema mangrove. None of the measured soil parameters could explain the variation of CH4 fluxes among the sampling plots. N2O flux was negatively related to porewater salinity, while CO2 flux was negatively correlated with water content and organic carbon. This study suggested that the low gas emissions due to slow metabolisms would lead to the accumulations of organic matters in North Sulawesi mangrove swamps. PMID:24784732

  10. Simple synthesis of Al2O3 sphere composite from hybrid process with improved thermal stability for catalytic applications

    International Nuclear Information System (INIS)

    Aluminium oxide spheres were synthesized by the hybrid process applying the biopolymer chitosan. After the calcination process the porous spheres were characterized by Chemical elemental analysis (XRF), X-ray diffraction (XRD), Scanning electron microscopy and Energy Dispersive X-ray Spectroscopy (SEM-EDS), N2 adsorption–desorption isotherms, infrared spectroscopy (IR), and CO2 temperature programmed desorption (CO2-TPD). The effect of thermal treatment on surface properties of the oxide spheres was also evaluated by the catalytic ethanol dehydration reaction. The hybrid method produced interesting results related to the thermal stability against sintering process and consequently low decreases of surface area. The hybrid spheres calcination at 900 and 1200 °C produced a metastable phases of alumina with a high surface area, and nanometric crystallites. Additionally, the spheres of mixed silica-alumina synthesized by this method reveal the formation of porous spheres with highly acidic OH groups, which was suggested by the catalytic performance. - Highlights: • Al and Si/Al oxide spheres with promising properties are synthesized by hybrid method. • Al2O3 spheres show high thermal stability and resistance the loss surface area. • The SiO2 addition plays an important role in the structure and porosity of the spheres. • Al2O3 and SiO2/Al2O3 spheres presented a good activity to conversion ethanol. • The activity is related to the surface area and density of OH groups on surface

  11. Discovery of a Gas-Rich Companion to the Extremely Metal-Poor Galaxy DDO 68

    CERN Document Server

    Cannon, John M; McQuinn, Kristen B W; Alfvin, Erik D; Bailin, Jeremy; Ford, H Alyson; Girardi, Léo; Hirschauer, Alec S; Janowiecki, Steven; Salzer, John J; Van Sistine, Angela; Dolphin, Andrew; Elson, E C; Koribalski, Baerbel; Marigo, Paola; Rosenberg, Jessica L; Rosenfield, Philip; Skillman, Evan D; Venkatesan, Aparna; Warren, Steven R

    2014-01-01

    We present HI spectral-line imaging of the extremely metal-poor galaxy DDO 68. This system has a nebular oxygen abundance of only 3% Z$_{\\odot}$, making it one of the most metal-deficient galaxies known in the local volume. Surprisingly, DDO 68 is a relatively massive and luminous galaxy for its metal content, making it a significant outlier in the mass-metallicity and luminosity-metallicity relationships. The origin of such a low oxygen abundance in DDO 68 presents a challenge for models of the chemical evolution of galaxies. One possible solution to this problem is the infall of pristine neutral gas, potentially initiated during a gravitational interaction. Using archival HI spectral-line imaging obtained with the Karl G. Jansky Very Large Array, we have discovered a previously unknown companion of DDO 68. This low-mass (M$_{\\rm HI}$ $=$ 2.8$\\times$10$^{7}$ M$_{\\odot}$), recently star-forming (SFR$_{\\rm FUV}$ $=$ 1.4$\\times$10$^{-3}$ M$_{\\odot}$ yr$^{-1}$, SFR$_{\\rm H\\alpha}$ $<$ 7$\\times$10$^{-5}$ M$_{\\...

  12. Fission track astrology of three Apollo 14 gas-rich breccias

    Science.gov (United States)

    Graf, H.; Shirck, J.; Sun, S.; Walker, R.

    1973-01-01

    The three Apollo 14 breccias 14301, 14313, and 14318 all show fission xenon due to the decay of Pu-244. To investigate possible in situ production of the fission gas, an analysis was made of the U-distribution in these three breccias. The major amount of the U lies in glass clasts and in matrix material and no more than 25% occurs in distinct high-U minerals. The U-distribution of each breccia is discussed in detail. Whitlockite grains in breccias 14301 and 14318 found with the U-mapping were etched and analyzed for fission tracks. The excess track densities are much smaller than indicated by the Xe-excess. Because of a preirradiation history documented by very high track densities in feldspar grains, however, it is impossible to attribute the excess tracks to the decay of Pu-244. A modified track method has been developed for measuring average U-concentrations in samples containing a heterogeneous distribution of U in the form of small high-U minerals. The method is briefly discussed, and results for the rocks 14301, 14313, 14318, 68815, 15595, and the soil 64421 are given.

  13. Selective catalytic reduction system and process for treating NOx emissions using a zinc or titanium promoted palladium-zirconium catalyst

    Science.gov (United States)

    Sobolevskiy, Anatoly; Rossin, Joseph A.; Knapke, Michael J.

    2011-08-02

    A process and system (18) for reducing NO.sub.x in a gas using hydrogen as a reducing agent is provided. The process comprises contacting the gas stream (29) with a catalyst system (38) comprising sulfated zirconia washcoat particles (41), palladium, a pre-sulfated zirconia binder (44), and a promoter (45) comprising at least one of titanium, zinc, or a mixture thereof. The presence of zinc or titanium increases the resistance of the catalyst system to a sulfur and water-containing gas stream.

  14. Modeling and Optimization of the Rich Gas-Condensate Reservoir: Upstream, Midstream and Downstream Integration

    OpenAIRE

    Abdrakhmanov, Adkar

    2013-01-01

    Simulation and Optimization of the production assets occurs in several and various cycles.Those are: "Field Management", "Production Optimization" and "Operation Efficiency". Decisions making process obviously based on analyzing of those cycles. "Field Management" cycle is a multidisciplinary, detail numerical modeling of the Reservoir, Field Facility (Wells&Pipelines) and Surface(Separator++) Facility. "Production Optimization" involve...

  15. 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.

  16. Arsenophilic Bacterial Processes in Searles Lake: A Salt-saturated, Arsenic-rich, Alkaline Soda Lake.

    Science.gov (United States)

    Oremland, R. S.; Kulp, T. R.; Hoeft, S. E.; Miller, L. G.; Swizer Blum, J.; Stolz, J. F.

    2005-12-01

    likely brine concentration reactions (e.g., evapo- and cryo-concentration) occurring in its early Noachian/Hesperian epochs. We speculate that these processes may have created arsenic-rich, dense brines on the Martian surface or even within its underlying regolith. Whether such brines persisted long enough for prokaryotic life to evolve in them, and if so, was such life capable of adapting to and exploiting arsenic redox reactions for the purpose of generating metabolic energy remain tantalizing, but still hypothetical questions.

  17. Data Processing Model of Coalmine Gas Early-Warning System

    Institute of Scientific and Technical Information of China (English)

    QIAN Jian-sheng; YIN Hong-sheng; LIU Xiu-rong; HUA Gang; XU Yong-gang

    2007-01-01

    The data processing mode is vital to the performance of an entire coalmine gas early-warning system, especially in real-time performance. Our objective was to present the structural features of coalmine gas data, so that the data could be processed at different priority levels in C language. Two different data processing models, one with priority and the other without priority, were built based on queuing theory. Their theoretical formulas were determined via a M/M/1 model in order to calculate average occupation time of each measuring point in an early-warning program. We validated the model with the gas early-warning system of the Huaibei Coalmine Group Corp. The results indicate that the average occupation time for gas data processing by using the queuing system model with priority is nearly 1/30 of that of the model without priority..

  18. Contracting out gas processing : the pros and cons

    International Nuclear Information System (INIS)

    The impact of competition within the energy industry on the midstream infrastructure was discussed. It was demonstrated that it is no longer necessary to own all or a portion of a processing facility to be a successful exploration company. It is now possible for midstream operators to manage the transmission business, the gas storage sector and the gas processing segment of the industry. Contract options and issues that should be addressed by natural gas producers in determining risks involved in contracting out were summarized. Changes in the industry has greatly expanded the options and opportunities for companies, both upstream and midstream. The industry has been contracting out gas processing for many years. However, the entry into the business of the specialized midstream player should further enhance the producer's options. The ultimate goal for the producer should be to benefit from lower costs, long term offerings, and a reduced need to invest potential exploration capital into non-core processing facilities

  19. 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.

  20. Nitrogen Availability Of Nitriding Atmosphere In Controlled Gas Nitriding Processes

    OpenAIRE

    Michalski J; Burdyński K.; Wach P.; Łataś Z.

    2015-01-01

    Parameters which characterize the nitriding atmosphere in the gas nitriding process of steel are: the nitriding potential KN, ammonia dissociation rate α and nitrogen availabilitymN2. The article discusses the possibilities of utilization of the nitriding atmosphere’s nitrogen availability in the design of gas nitriding processes of alloyed steels in atmospheres derived from raw ammonia, raw ammonia diluted with pre-dissociated ammonia, with nitrogen, as well as with both nitrogen and pre-dis...

  1. Evaluation of Chilled Methanol Processes for Acid Gas Removal

    OpenAIRE

    Piña Dreyer, Manuel

    2011-01-01

    As the main goal achieved with this master thesis, a plant design was constructed for an acid gas removal process with methanol operating at low temperatures. First, a bibliographical research was made in terms of sour gas treatment; with special focus of physical absorption processes involving methanol as the solvent to achieve separation; such as Rectisol and Ifpexsol. The literature research was extended to thermodynamic data; compiling equilibrium values for binary systems between methano...

  2. Manufacture of ammonium sulfate fertilizer from gypsum-rich byproduct of flue gas desulfurization - A prefeasibility cost estimate

    Science.gov (United States)

    Chou, I.-Ming; Rostam-Abadi, M.; Lytle, J.M.; Achorn, F.P.

    1996-01-01

    Costs for constructing and operating a conceptual plant based on a proposed process that converts flue gas desulfurization (FGD)-gypsum to ammonium sulfate fertilizer has been calculated and used to estimate a market price for the product. The average market price of granular ammonium sulfate ($138/ton) exceeds the rough estimated cost of ammonium sulfate from the proposed process ($111/ ton), by 25 percent, if granular size ammonium sulfate crystals of 1.2 to 3.3 millimeters in diameters can be produced by the proposed process. However, there was at least ??30% margin in the cost estimate calculations. The additional costs for compaction, if needed to create granules of the required size, would make the process uneconomical unless considerable efficiency gains are achieved to balance the additional costs. This study suggests the need both to refine the crystallization process and to find potential markets for the calcium carbonate produced by the process.

  3. Natural gas operations: considerations on process transients, design, and control.

    Science.gov (United States)

    Manenti, Flavio

    2012-03-01

    This manuscript highlights tangible benefits deriving from the dynamic simulation and control of operational transients of natural gas processing plants. Relevant improvements in safety, controllability, operability, and flexibility are obtained not only within the traditional applications, i.e. plant start-up and shutdown, but also in certain fields apparently time-independent such as the feasibility studies of gas processing plant layout and the process design of processes. Specifically, this paper enhances the myopic steady-state approach and its main shortcomings with respect to the more detailed studies that take into consideration the non-steady state behaviors. A portion of a gas processing facility is considered as case study. Process transients, design, and control solutions apparently more appealing from a steady-state approach are compared to the corresponding dynamic simulation solutions. PMID:22056010

  4. Catalytic acceleration of extraction process with solvent containing soft functional groups

    International Nuclear Information System (INIS)

    It is shown that a rate of equilibrium attainment in the extraction of salt of a ''soft'' type metal from nitric acid solutions by a solvent with ''soft'' functional group, for example in Pdsup((2)) extraction by dialkyl sulfide, may be essentially increased by the addition of extracting agent with functional groups including ''hard'' nucleophilic atoms, for example TBP, even in the case, when this extracting agent extracts ''soft'' cation salt rather weakly. The observed catalytic effect may be explained by the fact that, as opposed to molecules with ''soft'' functional groups, TBP molecules and molecules of other nucleophilic extracting agents with ''hard'' donor atoms are concentrated on the phase interface and therefore they react quicker with ''soft'' cation salts during phase contact converting them to the organic phase volume in a solvate form, where the latter reacts quickly with a ''soft'' extracting agent forming thermodynamically stable complex

  5. Catalytic acceleration of the process in extraction with a solvent with ''soft'' functional groups

    International Nuclear Information System (INIS)

    It is shown that the rate of reaching of equilibrium in extraction of a metal salt ''soft'' type from nitric acid solutions by a solvent with a ''soft'' functional group in the extraction of Pd(II) by dialkyl sulfide, can be increased substantially by the addition of an extraction reagent with functional groups including ''hard'' nucleophilic atoms, for example TBP, to the organic phase, even when this extraction reagent itself extracts the salt of the ''soft'' cation weakly. The type of catalytic acceleration of extraction found is probably of a general nature and may be observed in various systems where the salt of a ''soft'' cation is extracted by a ''soft'' extraction reagent in the presence of an addition of a ''hard'' extraction reagent

  6. Review on biofuel oil and gas production processes from microalgae

    International Nuclear Information System (INIS)

    Microalgae, as biomass, are a potential source of renewable energy, and they can be converted into energy such as biofuel oil and gas. This paper presents a brief review on the main conversion processes of microalgae becoming energy. Since microalgae have high water content, not all biomass energy conversion processes can be applied. By using thermochemical processes, oil and gas can be produced, and by using biochemical processes, ethanol and biodiesel can be produced. The properties of the microalgae product are almost similar to those of offish and vegetable oils, and therefore, it can be considered as a substitute of fossil oil.

  7. 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

  8. Development of a Low NOx Medium sized Industrial Gas Turbine Operating on Hydrogen-Rich Renewable and Opportunity Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, Ram

    2013-07-31

    This report presents the accomplishments at the completion of the DOE sponsored project (Contract # DE-FC26-09NT05873) undertaken by Solar Turbines Incorporated. The objective of this 54-month project was to develop a low NOx combustion system for a medium sized industrial gas turbine engine operating on Hydrogen-rich renewable and opportunity Fuels. The work in this project was focused on development of a combustion system sized for 15MW Titan 130 gas turbine engine based on design analysis and rig test results. Although detailed engine evaluation of the complete system is required prior to commercial application, those tasks were beyond the scope of this DOE sponsored project. The project tasks were organized in three stages, Stages 2 through 4. In Stage 2 of this project, Solar Turbines Incorporated characterized the low emission capability of current Titan 130 SoLoNOx fuel injector while operating on a matrix of fuel blends with varying Hydrogen concentration. The mapping in this phase was performed on a fuel injector designed for natural gas operation. Favorable test results were obtained in this phase on emissions and operability. However, the resulting fuel supply pressure needed to operate the engine with the lower Wobbe Index opportunity fuels would require additional gas compression, resulting in parasitic load and reduced thermal efficiency. In Stage 3, Solar characterized the pressure loss in the fuel injector and developed modifications to the fuel injection system through detailed network analysis. In this modification, only the fuel delivery flowpath was modified and the air-side of the injector and the premixing passages were not altered. The modified injector was fabricated and tested and verified to produce similar operability and emissions as the Stage 2 results. In parallel, Solar also fabricated a dual fuel capable injector with the same air-side flowpath to improve commercialization potential. This injector was also test verified to produce 15

  9. Critically designing today’s melt processed bulk magnesium alloys using boron rich nanoparticles

    International Nuclear Information System (INIS)

    Highlights: • B4C nanoparticles increased the tensile ductility of Mg–Al alloy to about 25%. • SiB6 nanoparticles increased the tensile ductility of Mg–Zn alloy to about 23%. • ZrB2 nanoparticles increased the tensile strength of Mg–RE alloy to above 400 MPa. • Hypothetically, 5–10% cold working could significantly increase tensile strength. • Hypothetically, 5–10% cold working could maintain tensile ductility above 10%. - Abstract: In this work, boron rich nanoparticles (B4C, SiB6 and ZrB2) were added to bulk melt processed Mg–Al, Mg–Zn and Mg–RE (Rare Earth) series contemporary magnesium alloys, respectively. The most obvious positive effect when adding B4C nanoparticles to the Mg–Al alloy was the significant increase in tensile ductility (to about 25%). Here, there was no significant change in grain size or crystallographic texture due to nanoparticle addition. However, it was observed that stacking faults formed more easily in the magnesium matrix due to nanoparticle addition. Also, it was observed that coarser nanoparticles broke down high strain zones (HSZs) during tensile deformation. The addition of SiB6 to Mg–Zn alloy also resulted in similar significant increase in tensile ductility (to about 23%). Tensile deformation induced alignment of more rounded and spherical nanoparticles was observed. Stacking faults forming more easily in the alloy matrix was also observed. However, the formation of nanograins (nanoscale recrystallization) during room temperature tensile deformation was observed in this system. This implied that nanograin rotation during deformation was also responsible for the observed enhanced tensile ductility. When ZrB2 was added to Mg–RE alloy, the tensile strength was significantly enhanced (yield strength >400 MPa) after thermal ageing. Here, the ZrB2 nanoparticles induced the formation of thermal ageing resistant long period stacking/ordered (LPSO) nanograins and nanolayers in the Mg–RE alloy matrix

  10. Diagnostics of metal inert gas and metal active gas welding processes

    Science.gov (United States)

    Uhrlandt, D.

    2016-08-01

    The paper gives a review on studies on metal inert gas (MIG) and metal active gas (MAG) welding processes with the focus on diagnostics of the arc, the material transfer, and the temporal process behaviour in welding experiments. Recent findings with respect to an improved understanding of the main mechanisms in the welding arc and the welding process are summarized. This is linked to actual developments in welding arc and welding process modelling where measurements are indispensable for validation. Challenges of forthcoming studies are illustrated by means of methods under development for welding process control as well as remaining open questions with respect to arc-surface interaction and arc power balance.

  11. Plasma reforming of bio-ethanol for hydrogen rich gas production

    International Nuclear Information System (INIS)

    Highlights: • The steam-oxidative reforming of ethanol was performed in a novel miniaturized plasma reactor. • The discharge combines the advantages of the 3-D cylindrical tornado and the supersonic/subsonic discharge. • The influence of V–I characteristic on ethanol reforming was discussed. • High conversion of ethanol was experimentally confirmed. - Abstract: Hydrogen production from ethanol by non-thermal arc discharge was investigated in a novel miniaturized plasma reactor. It is observed that ethanol–water mixture was converted into hydrogen, carbon monoxide and other products. The V–I characteristic was recorded by an oscilloscope to study the effect of discharge on the ethanol reforming. In the experiments, ethanol–water mixture entered the reaction chamber through a special gas–liquid spray nozzle for a quick evaporation and a rapid mixing with air at room temperature. Assisted by a Laval nozzle electrode, non-thermal arc plasma can improve the performance of ethanol reforming. It is found that the maximum conversion rate of ethanol was 90.9% at O/C = 1.4, S/C = 1.2 and ethanol flow rate = 0.05 g/s, and the maximum hydrogen yield was 40.9% at O/C = 1.4, S/C = 1.2 and ethanol flow rate = 0.10 g/s. The ethanol reforming process produced little coke and nitrogen oxide which was less than 10 ppm in the supersonic/subsonic plasma working condition

  12. Analysis of gas turbine integrated cogeneration plant: Process integration approach

    International Nuclear Information System (INIS)

    Cogeneration is defined as generation of two forms of energy viz. heat and work using single primary fuel. Cogeneration or combined heat and power (CHP) is important in improving energy efficiency of the overall plant and in reducing environmental pollution. A methodology, based on pinch analysis, is proposed in this paper to integrate gas turbine and regenerator with a process plant to minimize fuel consumption. Thermodynamic analysis of gas turbine integrated CHP plant is presented on gas turbine pressure ratio versus power to heat ratio diagram. On this novel diagram, limits of integration are identified and various regions of integration are represented. Additionally, contour plots of energy utilization factors and fuel energy saving ratios are represented on this diagram for optimal integration of gas turbine with a process plant. It is interesting to note that though the contour plots of energy utilization factors and fuel energy saving ratios differ significantly, loci of the maximal energy utilization factor and the maximal fuel energy saving ratio are identical. Optimum sizing of gas turbine integrated cogeneration plant for grassroots design and retrofitting are performed based on these diagrams. - Highlights: • Methodology for direct integration of gas turbine, regenerator, and process plant. • Integrated system analysis plotted on turbine pressure ratio vs. power to heat ratio. • Regions of integration are identified on this new diagram. • Variations of energy utilization factor and fuel energy saving ratio are indicated. • Optimal sizing of integrated gas turbine for retrofitting and grassroots design

  13. Gas hydrate identified in sand-rich inferred sedimentary section using downhole logging and seismic data in Shenhu area, South China Sea

    Science.gov (United States)

    Wang, Xiujuan; Lee, Myung W.; Collett, Timothy S.; Yang, Shengxiong; Guo, Yiqun; Wu, Shiguo

    2014-01-01

    Downhole wireline log (DWL) data was acquired from eight drill sites during China's first gas hydrate drilling expedition (GMGS-1) in 2007. Initial analyses of the acquired well log data suggested that there were no significant gas hydrate occurrences at Site SH4. However, the re-examination of the DWL data from Site SH4 indicated that there are two intervals of high resistivity, which could be indicative of gas hydrate. One interval of high resistivity at depth of 171–175 m below seafloor (mbsf) is associated with a high compressional- wave (P-wave) velocities and low gamma ray log values, which suggests the presence of gas hydrate in a potentially sand-rich (low clay content) sedimentary section. The second high resistivity interval at depth of 175–180 mbsf is associated with low P-wave velocities and low gamma values, which suggests the presence of free gas in a potentially sand-rich (low clay content) sedimentary section. Because the occurrence of free gas is much shallower than the expected from the regional depth of the bottom simulating reflector (BSR), the free gas could be from the dissociation of gas hydrate during drilling or there may be a local anomaly in the depth to the base of the gas hydrate stability zone. In order to determine whether the low P-wave velocity with high resistivity is caused by in-situ free gas or dissociated free gas from the gas hydrate, the surface seismic data were also used in this analysis. The log analysis incorporating the surface seismic data through the construction of synthetic seismograms using various models indicated the presence of free gas directly in contact with an overlying gas hydrate-bearing section. The occurrence of the anomalous base of gas hydrate stability at Site SH4 could be caused by a local heat flow conditions. This paper documents the first observation of gas hydrate in what is believed to be a sand-rich sediment in Shenhu area of the South China Sea.

  14. Design, Control and in Situ Visualization of Gas Nitriding Processes

    OpenAIRE

    Jerzy Ratajski; Roman Olik; Tomasz Suszko; Jerzy Dobrodziej; Jerzy Michalski

    2009-01-01

    The article presents a complex system of design, in situ visualization and control of the commonly used surface treatment process: the gas nitriding process. In the computer design conception, analytical mathematical models and artificial intelligence methods were used. As a result, possibilities were obtained of the poly-optimization and poly-parametric simulations of the course of the process combined with a visualization of the value changes of the process parameters in the function of tim...

  15. Gas Turbine Ontology for the Industrial Processes

    Directory of Open Access Journals (Sweden)

    F. Z. Laallam

    2007-01-01

    Full Text Available The activity of supervision and control of the industrial processes is a very complex spot and require a great experiment because of the dynamic characteristics of the process. This experiment was acquired with the passing of years. What makes departure of an expert in retirement a great loss of the know-how. The problem thus consists to capture this know-how and allows experiment to be cumulate with an aim of construction of an enterprise memory. We propose an approach based on ontology to capture this know-how. In the dynamic situations are distinguished three classes from situations: situations of normal walk, situations of degraded walk and situations of incidental walk. The work presented in this article, was developed in the division of production at SONATRACH. It relates to the supervision and the control of the industrial process of a compressor station witch constitutes a typical case of dynamic situation. Among the three classes of quoted dynamic situations, we concentrate on the situations of degraded walk. These situations of nature different compared to the usual situations from normal walk, subject the operator to a workload at the same time complex and stressing. The work presented in this article enters within the framework of a doctoral project whose the principal objective was the development of an intelligent system of expertise and of decision-making aid in the domain of the industrial maintenance for the compression stations. It relates to ontological engineering and more particularly the use of ontologies in the knowledge-based systems. We try in this work to build an ontology concerning the domain of the industrial maintenance. This ontology was not operational yet because it does not included mechanisms of reasoning. It was independent of any context of use.

  16. Radon gas distribution in natural gas processing facilities and workplace air environment

    International Nuclear Information System (INIS)

    Evaluation has been made for the distribution of radon gas and radiation exposure rates in the four main natural gas treatment facilities in Syria. The results have shown that radiation exposure rates at contact of all equipment were within the natural levels (0.09 - 0.1 μSvhr-1) except for the reflex pumps where a dose rate value of 3 μSvhr-1 was recorded. Radon concentration in syrian natural gas varied between 15.4 Bqm-3 and 1141 Bqm-3, natural gas associated with oil production was found to contain higher concentration than the non-associated natural gas. In addition, radon concentrations were higher in the central processing facilities than the wellheads; these high levels are due to pressurizing and concentrating processes that enhance radon gas and its decay products. Moreover, the lowest 222Rn concentration was found to be in the natural gas fraction used for producing sulfur, a value of 80 Bqm-3 was observed. On the other hand, maximum radon gas and its decay products concentrations in workplace air environment were found to be relatively high in the gas analysis laboratories; a value of 458 Bqm-3 was observed. However, all reported levels in the workplaces in the four main stations were below the action level set by IAEA for chronic exposure situations involving radon, which is 1000 Bqm-3. (author)

  17. Radon gas distribution in natural gas processing facilities and workplace air environment

    International Nuclear Information System (INIS)

    Evaluation was made of the distribution of radon gas and radiation exposure rates in the four main natural gas treatment facilities in Syria. The results showed that radiation exposure rates at contact of all equipment were within the natural levels (0.09-0.1 μSv h-1) except for the reflex pumps where a dose rate value of 3 μSv h-1 was recorded. Radon concentrations in Syrian natural gas varied between 15.4 Bq m-3 and 1141 Bq m-3; natural gas associated with oil production was found to contain higher concentrations than the non-associated natural gas. In addition, radon concentrations were higher in the central processing facilities than the wellheads; these high levels are due to pressurizing and concentrating processes that enhance radon gas and its decay products. Moreover, the lowest 222Rn concentration was in the natural gas fraction used for producing sulfur; a value of 80 Bq m-3 was observed. On the other hand, maximum radon gas and its decay product concentrations in workplace air environments were found to be relatively high in the gas analysis laboratories; a value of 458 Bq m-3 was observed. However, all reported levels in the workplaces in the four main stations were below the action level set by IAEA for chronic exposure situations involving radon, which is 1000 Bq m-3

  18. Hydrothermal processing of fermentation residues in a continuous multistage rig – Operational challenges for liquefaction, salt separation, and catalytic gasification

    International Nuclear Information System (INIS)

    Fermentation residues are a waste stream of biomethane production containing substantial amounts of organic matter, and thus representing a primary energy source which is mostly unused. For the first time this feedstock was tested for catalytic gasification in supercritical water (T ≥ 374 °C, p ≥ 22 MPa) for methane production. The processing steps include hydrothermal liquefaction, salt separation, as well as catalytic gasification over a ruthenium catalyst in supercritical water. In continuous experiments at a feed rate of 1 kg h−1 a partial liquefaction and carbonization of some of the solids was observed. Significant amounts of heavy tars were formed. Around 50% of the feed carbon remained in the rig. Furthermore, a homogeneous coke was formed, presumably originating from condensed tars. The mineralization of sulfur and its separation in the salt separator was insufficient, because most of the sulfur was still organically bound after liquefaction. Desalination was observed at a salt separator set point temperature of 450 °C and 28 MPa; however, some of the salts could not be withdrawn as a concentrated brine. At 430 °C no salt separation took place. Higher temperatures in the salt separator were found to promote tar and coke formation, resulting in conflicting process requirements for efficient biomass liquefaction and desalination. In the salt separator effluent, solid crystals identified as struvite (magnesium ammonium phosphate) were found. This is the first report of struvite formation from a supercritical water biomass conversion process and represents an important finding for producing a fertilizer from the separated salt brine. - Highlights: • Continuous processing of fermentation residues in sub- and supercritical water. • Continuous separation of salt brines at supercritical water conditions. • Struvite crystals (magnesium ammonium phosphate) were recovered from the effluent. • Separation of sulfur from the biomass could not

  19. Geochemical characteristics and formation process of natural gas in Kela 2 gas field

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    On the basis of a large amount of natural gas components and the carbon isotope as well as some other analysis data in Kela 2 gas field, the geochemical characteristics, source, origin, and formation process of natural gas have been discussed. The components of gas in the field tend to be "dry", and the drying coefficient is close to 1.0. The carbon isotope tends to be heavier, for instance, the average of 13C1 is 27.36‰ and that of 13C2 is 18.5‰. Comprehensive analysis shows that humic natural gas in the Kuqa petroleum system comes mainly from Triassic and Jurassic source rocks, and the contribution of Jurassic source rocks to the pool maybe is more than that of Triassic rocks. The main cause that the gas tends to be dry and bears heavier isotope composition lies in the fact that Kela 2 natural gas is the accumulation of late production of humic source rocks, and it is affected by the abnormal high pressure as well. Considering the hydrocarbon generating and structural history, we can regard the gas pool formation processes as twice filling and twice adjusting (destroying), that is, the filling and destroying process in the early Himalayan movement and the filling and adjusting in the late Himalayan movement.

  20. Biodiesel production with continuous supercritical process: non-catalytic transesterification and esterification with or without carbon dioxide.

    Science.gov (United States)

    Tsai, Yu-Ting; Lin, Ho-mu; Lee, Ming-Jer

    2013-10-01

    The non-catalytic transesterification of refined sunflower oil with supercritical methanol, in the presence of carbon dioxide, was conducted in a tubular reactor at temperatures from 553.2 to 593.2K and pressures up to 25.0 MPa. The FAME yield can be achieved up to about 0.70 at 593.2 K and 10.0 MPa in 23 min with methanol:oil of 25:1 in molar ratio. The effect of adding CO2 on the FAME yield is insignificant. The kinetic behavior of the non-catalytic esterification and transesterification of oleic acid or waste cooking oil (WCO) with supercritical methanol was also investigated. By using the supercritical process, the presence of free fatty acid (FFA) in WCO gives positive contribution to FAME production. The FAME yield of 0.90 from WCO can be achieved in 13 min at 573.2K. The kinetic data of supercritical transesterification and esterifaication were correlated well with a power-law model. PMID:23339904

  1. The performance of a monolithic catalytic converter of automobile exhaust gas with oscillatory feeding of CO, NO, and O{sub 2}. A modelling study

    Energy Technology Data Exchange (ETDEWEB)

    Nievergeld, A.J.L.; Hoebink, J.H.B.J.; Marin, G.B. [Lab. voor Chemische Technologie, Eindhoven Univ. of Technology, Eindhoven (Netherlands)

    1995-12-31

    An isothermal monolithic catalytic converter of automobile exhaust gas was modelled in order to assess the effects of oscillatory feeding of CO, O{sub 2} and NO on the performance of the reactor. The influence of the temperature, frequency, and amplitude on the time average conversions was investigated. An improvement relative to the steady state conversion of 8% for CO and 30% for NO can be obtained. An explanation is given in terms of strongly changing surface coverage during cycling of the feed concentrations. 9 figs., 5 tabs., 16 refs.

  2. ALFALFA Discovery of the Nearby Gas-Rich Dwarf Galaxy Leo P. IV. Distance Measurement from LBT Optical Imaging

    CERN Document Server

    McQuinn, Kristen B W; Berg, Danielle; Cannon, John M; Salzer, John J; Adams, Elizabeth A K; Dolphin, Andrew; Giovanelli, Riccardo; Haynes, Martha P; Rhode, Katherine L

    2013-01-01

    Leo P is a low-luminosity dwarf galaxy discovered through the blind HI Arecibo Legacy Fast ALFA (ALFALFA) survey. The HI and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with both active star formation and an underlying older population, as well as an extremely low oxygen abundance. Here, we measure the distance to Leo P by applying the tip of the red giant branch (TRGB) distance method to photometry of the resolved stellar population from new Large Binocular Telescope (LBT) V and I band imaging. We measure a distance modulus of 26.19 (+0.17/-0.50) mag corresponding to a distance of 1.72 (+0.14/-0.40) Mpc. Although our photometry reaches 3 magnitudes below the TRGB, the sparseness of the red giant branch (RGB) yields higher uncertainties on the lower limit of the distance. Leo P is outside the Local Group with a distance and velocity consistent with the local Hubble flow. While located in a very low-density environment, Leo P lies within ~0.5 Mpc of a loose association of dw...

  3. Kinematics of dwarf galaxies in gas-rich groups, and the survival and detectability of tidal dwarf galaxies

    CERN Document Server

    Sweet, Sarah M; Meurer, Gerhardt; Kilborn, Virginia; Audcent-Ross, Fiona; Baumgardt, Holger; Bekki, Kenji

    2015-01-01

    We present DEIMOS multi-object spectroscopy (MOS) of 22 star-forming dwarf galaxies located in four gas-rich groups, including six newly-discovered dwarfs. Two of the galaxies are strong tidal dwarf galaxy (TDG) candidates based on our luminosity-metallicity relation definition. We model the rotation curves of these galaxies. Our sample shows low mass-to-light ratios (M/L=0.73$\\pm0.39M_\\odot/L_\\odot$) as expected for young, star-forming dwarfs. One of the galaxies in our sample has an apparently strongly-falling rotation curve, reaching zero rotational velocity outside the turnover radius of $r_{turn}=1.2r_e$. This may be 1) a polar ring galaxy, with a tilted bar within a face-on disk; 2) a kinematic warp. These scenarios are indistinguishable with our current data due to limitations of slit alignment inherent to MOS-mode observations. We consider whether TDGs can be detected based on their tidal radius, beyond which tidal stripping removes kinematic tracers such as H$\\alpha$ emission. When the tidal radius i...

  4. Lipids rich in phosphatidylethanolamine from natural gas-utilizing bacteria reduce plasma cholesterol and classes of phospholipids

    DEFF Research Database (Denmark)

    Müller, H.; Hellgren, Lars; Olsen, E.;

    2004-01-01

    We compared the effects of three different high-lipid diets on plasma lipoproteins and phospholipids in mink (Mustela vison). The 18 mink studied were fed one of the three diets during a 25-d period in a parallel group design. The compared diets had 0, 17, and 67% extracted lipids from natural gas......-utilizing bacteria (LNGB), which were rich in PE. The group with 0% LNGB was fed a diet for which the lipid content was 100% soybean oil. The total cholesterol, LDL cholesterol, and HDL cholesterol of animals consuming a diet with 67% LNGB (67LNGB-diet), were significantly lowered by 35, 49, and 29%, respectively......, and unesterified cholesterol increased by 17% compared with the animals fed a diet of 100% lipids from soybean oil (SB-diet). In addition, the ratio of LDL cholesterol to HDL cholesterol was 27% lower in mink fed the 67LNGB-diet than those fed the S13-cliet. When the mink were fed the 67LNGB...

  5. Peridote-water interaction generating migration pathways of H2-rich fluids in subduction context: Common processes in the ophiolites of Oman, New-Caledonia, Philippines and Turkey

    Science.gov (United States)

    Deville, E. P.; Prinzhofer, A.; Pillot, D.; Vacquand, C.; Sissmann, O.

    2010-12-01

    The occurrence of H2 flows which were punctually known notably in the ophiolites of Oman, Zambales (Philippines) and Antalya (Turkey) appears to be a widespread phenomenon in these major peridotite massifs associated with ancient or active subduction processes. Similar H2-rich gas flows have been discovered also in the peridotite of New-Caledonia. H2 concentrations are locally high (commonly 60 to90% in Oman). H2 is frequently degassing in hyperalkaline springs but the highest flows were found directly expelled from fractures in the peridotites. Obviously, within the fracture systems, gas and associated hyperalkaline water separate at shallow depth close to the top of the upper aquifer level. Locally high flows of gas migrate vertically in the fractures, whereas water with degassing H2 tends to migrate laterally in the fracture network toward the creeks where most of the hyperalkaline springs are found. The genesis of natural H2 is interpreted as the result of the interaction, at depth, between ultrabasic mantle rocks in the upper plate and water expelled by the subducted sediments by oxidation of metals (Fe2+, Mn2+) and reduction of water during serpentinisation. CH4 is commonly associated to the H2-rich fluids and it is interpreted as the result of the reduction of available CO2 at depth. N2 is also commonly associated to the H2-rich fluids in the ophiolites, whereas N2 flows (within H2) were found in the subducted sediments (below the sole décollement of the peridotite) where it can be observed (Oman and New-Caledonia). Within the peridotites, the hyperalkaline water is rich in ions OH- and Ca2+ and characterized by high pH (between 11 and 12). Most alkaline springs are found in the vicinity of major faults and/or lithological discontinuities like the basal décollement of the ophiolites and the peridotite-gabbro contact (Moho). This hyperalkaline water migration induces a chain of diagenetic reactions starting at depth within the fracture systems by the

  6. Tritium stripping by a catalytic exchange stripper

    International Nuclear Information System (INIS)

    A catalytic exchange process for stripping elemental tritium from gas streams has been demonstrated. The process uses a catalyzed isotopic exchange reaction between tritium in the gas phase and protium or deuterium in the solid phase on alumina. The reaction is catalyzed by platinum deposited on the alumina. The process has been tested with both tritium and deuterium. Decontamination factors (ration of inlet and outlet tritium concentrations) as high as 1000 have been achieved, depending on inlet concentration. The test results and some demonstrated applications are presented

  7. Process Investigation of Tube Expansion by Gas Detonation

    OpenAIRE

    Bach, F.-W.; Beerwald, C.; Brosius, A.; Gershteyn, G.; Hermes, M.; Kleiner, M.; Olivier, H.; M. Weber

    2006-01-01

    The present paper deals with the expansion of tubes by direct application of gas detonation waves, i.e. the gas is both pressure medium and energy source. After an introduction to gas detonation forming, measurements of the motion process and the internal pressures are presented. Results of free expansion and of forming into a die are thoroughly studied and compared to the results of quasi-static burst tests and hydroforming. Using pure aluminum Al99.5 and a medium strength alloy AlMgSi1, ...

  8. Method for treating a nuclear process off-gas stream

    International Nuclear Information System (INIS)

    A method is described for selectively removing and recovering the noble gas and other gaseous components typically emitted during nuclear process operations. The method is useful for treating dissolver off-gas effluents released during reprocessing of spent nuclear fuels to permit radioactive contaminant recovery prior to releasing the remaining off-gases to the atmosphere. The method involves a sequence of adsorption and desorption steps which are specified. Particular reference is made to the separation of xenon and krypton from the off-gas stream, and to the use of silver-exchanged mordenite as the adsorbent. (U.K.)

  9. Low-severity catalytic two-stage liquefaction process: Illinois coal conceptual commercial plant design and economics

    Energy Technology Data Exchange (ETDEWEB)

    Abrams, L.M.; Comolli, A.G.; Popper, G.A.; Wang, C.; Wilson, G.

    1988-09-01

    Hydrocarbon Research, Inc. (HRI) is conducting a program for the United States Department of Energy (DOE) to evaluate a Catalytic Two-Stage Liquefaction (CTSL) Process. This program which runs through 1987, is a continuation of an earlier DOE sponsored program (1983--1985) at HRI to develop a new technology concept for CTSL. The earlier program included bench-scale testing of improved operating conditions for the CTSL Process on Illinois No. 6 bituminous coal and Wyoming sub-bituminous coal, and engineering screening studies to identify the economic incentive for CTSL over the single-stage H-Coal/reg sign/ Process for Illinois No. 6 coal. In the current program these engineering screening studies are extended to deep-cleaned Illinois coal and use of heavy recycle. The results from this comparison will be used as a guide for future experiments with respect to selection of coal feedstocks and areas for further process optimization. A preliminary design for CTSL of Illinois deep-cleaned coal was developed based on demonstrated bench-scale performance in Run No. 227-47(I-27), and from HRI's design experience on the Breckinridge Project and H-Coal/reg sign/ Process pilot plant operations at Catlettsburg. Complete conceptual commercial plant designs were developed for a grassroots facility using HRI's Process Planning Model. Product costs were calculated and economic sensitivities analyzed. 14 refs., 11 figs., 49 tabs.

  10. Dimensional effects in the radiation-catalytic processes of water decomposition and perspectives of application of nanocatalysts

    International Nuclear Information System (INIS)

    Full text : According to the value of the coefficient of energy sources of radiation, selectivity and productivity, radiation-heterogeneous processes are one of the promising areas of radioactive processes. Interest to radiating and heterogeneous processes increased in communication by development of nuclear power systems, transformations of nuclear energy and atomic-hydrogen energy. The physical stage of radiation-heterogeneous processes comprises the steps of absorption, transformation, transport and energy transfer radiation sources. The efficiency of radioactive processes in heterogeneous systems is largely dependent on the parameters of constituent phases. In this work, the examples of the radiation-catalytic processes for hydrogen production from water presents the results of investigations of the influence of particle size of catalysts on the efficiency of energy conversion of ionizing radiation. As objects of investigation were taken oxide compounds SiO2, BeO, Al2O3, and aluminosilicates, beryllium silicates. The physical stage of radiation-heterogeneous processes was investigated by using model-calculated experiments. Calculation for well-known model of given processes of interaction of ionizing radiation with solids having the radiation-catalytic activity shows that in most experiments the energy of ionizing radiation is converted into energy imbalance of charge carriers (electrons and holes) excited states, and other defective states of the oxides. Investigated the individual and complex oxide systems containing metal oxides II-IV of the periodic table of elements. There are positions of cat ions and anions, which are the centers of localization of no equilibrium charge carriers in the ground state charged and(where 2 = 2, 4). With the capture of no equilibrium charge carriers in [3] and [4], these centers pass into the state, as a clear signs of the charges of these centers does not change. Therefore, in these oxides, the recombination of free particles

  11. Nitrogen Availability Of Nitriding Atmosphere In Controlled Gas Nitriding Processes

    Directory of Open Access Journals (Sweden)

    Michalski J.

    2015-06-01

    Full Text Available Parameters which characterize the nitriding atmosphere in the gas nitriding process of steel are: the nitriding potential KN, ammonia dissociation rate α and nitrogen availabilitymN2. The article discusses the possibilities of utilization of the nitriding atmosphere’s nitrogen availability in the design of gas nitriding processes of alloyed steels in atmospheres derived from raw ammonia, raw ammonia diluted with pre-dissociated ammonia, with nitrogen, as well as with both nitrogen and pre-dissociated ammonia. The nitriding processes were accomplished in four series. The parameters selected in the particular processes were: process temperature (T, time (t, value of nitriding potential (KN, corresponding to known dissociation rate of the ammonia which dissociates during the nitriding process (α. Variable parameters were: nitrogen availability (mN2, composition of the ingoing atmosphere and flow rate of the ingoing atmosphere (FIn.

  12. Sulfite oxidation catalyzed by cobalt ions in flue gas desulfurization processes.

    Science.gov (United States)

    Karatza, Despina; Prisciandaro, Marina; Lancia, Amedeo; Musmarra, Dino

    2010-06-01

    This paper presents an experimental study of calcium bisulfite oxidation, a key step in the wet limestone-gypsum flue gas desulfurization (FGD) process, in the presence of catalysts (e.g., cobalt ions and a mixture of ferrous and cobalt ions). A fundamental approach is followed, by reproducing a simplified synthetic FGD liquor in which both catalyst ions, alone or mixed together, are present. A laboratory-scale apparatus is used, in which sulfurous solution is contacted with a gas phase at a fixed oxygen partial pressure (21.3 kPa) and at different temperature levels (25, 45, and 55 degrees C). The experimental results are analyzed using the theory of gas-liquid mass transfer with chemical reaction, showing that the slow reaction regime is explored and the transition from the kinetic to the diffusional subregime is identified. The experimental results are compared with those obtained in the presence of other catalytic species (manganese and ferrous ions), showing that cobalt is effective in catalyzing the oxidation of calcium bisulfite to sulfate, but to a minor extent with respect to iron and manganese. PMID:20564992

  13. Kinetic-quantum chemical model for catalytic cycles: the Haber-Bosch process and the effect of reagent concentration.

    Science.gov (United States)

    Kozuch, Sebastian; Shaik, Sason

    2008-07-01

    A combined kinetic-quantum chemical model is developed with the goal of estimating in a straightforward way the turnover frequency (TOF) of catalytic cycles, based on the state energies obtained by quantum chemical calculations. We describe how the apparent activation energy of the whole cycle, so-called energetic span (delta E), is influenced by the energy levels of two species: the TOF determining transition state (TDTS) and the TOF determining intermediate (TDI). Because these key species need not be adjoining states, we conclude that for catalysis there are no rate-determining steps, only rate determining states. In addition, we add here the influence of reactants concentrations. And, finally, the model is applied to the Haber-Bosch process of ammonia synthesis, for which we show how to calculate which catalyst will be the most effective under specific reagents conditions. PMID:18537227

  14. Process development of short-chain polyols synthesis from corn stover by combination of enzymatic hydrolysis and catalytic hydrogenolysis

    Directory of Open Access Journals (Sweden)

    Zhen-Hong Fang

    2014-09-01

    Full Text Available Currently short-chain polyols such as ethanediol, propanediol, and butanediol are produced either from the petroleum feedstock or from the starch-based food crop feedstock. In this study, a combinational process of enzymatic hydrolysis with catalytic hydrogenolysis for short-chain polyols production using corn stover as feedstock was developed. The enzymatic hydrolysis of the pretreated corn stover was optimized to produce stover sugars at the minimum cost. Then the stover sugars were purified and hydrogenolyzed into polyols products catalyzed by Raney nickel catalyst. The results show that the yield of short-chain polyols from the stover sugars was comparable to that of the corn-based glucose. The present study provided an important prototype for polyols production from lignocellulose to replace the petroleum- or corn-based polyols for future industrial applications.

  15. Simulation calculations for a catalytic exchange/cryogenic distillation hydrogen isotope separation process

    International Nuclear Information System (INIS)

    Some of the aspects of the optimization and simulation calculations for the Moderator Detritiation Plant thay may be applicable to other processes are described. The FORTRAN optimization program and the CPES and PROCESS distillation calculation are covered

  16. Precision mass measurements on neutron-rich Zn isotopes and their consequences on the astrophysical r-process

    International Nuclear Information System (INIS)

    The rapid neutron-capture or the r-process is responsible for the origin of about half of the neutron-rich atomic nuclei in the universe heavier than iron. For the calculation of the abundances of those nuclei, atomic masses are required as one of the input parameters with very high precision. In the present work, the masses of the neutron rich Zn isotopes (A=71 to 81) lying in the r-process path have been measured in the ISOLTRAP experiment at ISOLDE/CERN. The mass of 81Zn has been measured directly for the rst time. The half-lives of the nuclides ranged from 46.5 h (72Zn) down to 290 ms (81Zn). In case of all the nuclides, the relative mass uncertainty (Δm=m) achieved was in the order of 10-8 corresponding to a 100-fold improvement in precision over previous measurements. (orig.)

  17. Precision mass measurements on neutron-rich Zn isotopes and their consequences on the astrophysical r-process

    Energy Technology Data Exchange (ETDEWEB)

    Baruah, Sudarshan

    2008-07-15

    The rapid neutron-capture or the r-process is responsible for the origin of about half of the neutron-rich atomic nuclei in the universe heavier than iron. For the calculation of the abundances of those nuclei, atomic masses are required as one of the input parameters with very high precision. In the present work, the masses of the neutron rich Zn isotopes (A=71 to 81) lying in the r-process path have been measured in the ISOLTRAP experiment at ISOLDE/CERN. The mass of {sup 81}Zn has been measured directly for the rst time. The half-lives of the nuclides ranged from 46.5 h ({sup 72}Zn) down to 290 ms ({sup 81}Zn). In case of all the nuclides, the relative mass uncertainty ({delta}m=m) achieved was in the order of 10{sup -8} corresponding to a 100-fold improvement in precision over previous measurements. (orig.)

  18. Overview of gas processing fee practices in Canada

    International Nuclear Information System (INIS)

    The negotiation of gas processing fees from the perspective of the natural gas producer are summarized. Some of the topics discussed are: evaluation of fee proposals, capital cost estimates, pipeline capital fees, compressor capital fees, plant capital fees, upper and lower limits on fees, (JP-90 and JP-95), negotiation options, operating costs, production allocation, and processing agreements. Several case studies involving one or more of these items were reviewed by way of illustration. The importance of documentation of all agreements, changes to agreements, commitments, etc., was stressed

  19. Task 3.3: Warm Syngas Cleanup and Catalytic Processes for Syngas Conversion to Fuels Subtask 3: Advanced Syngas Conversion to Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lebarbier Dagel, Vanessa M.; Li, J.; Taylor, Charles E.; Wang, Yong; Dagle, Robert A.; Deshmane, Chinmay A.; Bao, Xinhe

    2014-03-31

    This collaborative joint research project is in the area of advanced gasification and conversion, within the Chinese Academy of Sciences (CAS)-National Energy Technology Laboratory (NETL)-Pacific Northwest National Laboratory (PNNL) Memorandum of Understanding. The goal for this subtask is the development of advanced syngas conversion technologies. Two areas of investigation were evaluated: Sorption-Enhanced Synthetic Natural Gas Production from Syngas The conversion of synthetic gas (syngas) to synthetic natural gas (SNG) is typically catalyzed by nickel catalysts performed at moderate temperatures (275 to 325°C). The reaction is highly exothermic and substantial heat is liberated, which can lead to process thermal imbalance and destruction of the catalyst. As a result, conversion per pass is typically limited, and substantial syngas recycle is employed. Commercial methanation catalysts and processes have been developed by Haldor Topsoe, and in some reports, they have indicated that there is a need and opportunity for thermally more robust methanation catalysts to allow for higher per-pass conversion in methanation units. SNG process requires the syngas feed with a higher H2/CO ratio than typically produced from gasification processes. Therefore, the water-gas shift reaction (WGS) will be required to tailor the H2/CO ratio. Integration with CO2 separation could potentially eliminate the need for a separate WGS unit, thereby integrating WGS, methanation, and CO2 capture into one single unit operation and, consequently, leading to improved process efficiency. The SNG process also has the benefit of producing a product stream with high CO2 concentrations, which makes CO2 separation more readily achievable. The use of either adsorbents or membranes that selectively separate the CO2 from the H2 and CO would shift the methanation reaction (by driving WGS for hydrogen production) and greatly improve the overall efficiency and economics of the process. The scope of this

  20. Influence of size-induced oxidation state of platinum nanoparticles on selectivity and activity in catalytic methanol oxidation in the gas phase.

    Science.gov (United States)

    Wang, Hailiang; Wang, Yihai; Zhu, Zhongwei; Sapi, Andras; An, Kwangjin; Kennedy, Griffin; Michalak, William D; Somorjai, Gabor A

    2013-06-12

    Pt nanoparticles with various sizes of 1, 2, 4, and 6 nm were synthesized and studied as catalysts for gas-phase methanol oxidation reaction toward formaldehyde and carbon dioxide under ambient pressure (10 Torr of methanol, 50 Torr of oxygen, and 710 Torr of helium) at a low temperature of 60 °C. While the 2, 4, and 6 nm nanoparticles exhibited similar catalytic activity and selectivity, the 1 nm nanoparticles showed a significantly higher selectivity toward partial oxidation of methanol to formaldehyde, but a lower total turnover frequency. The observed size effect in catalysis was correlated to the size-dependent structure and oxidation state of the Pt nanoparticles. X-ray photoelectron spectroscopy and infrared vibrational spectroscopy using adsorbed CO as molecular probes revealed that the 1 nm nanoparticles were predominantly oxidized while the 2, 4, and 6 nm nanoparticles were largely metallic. Transmission electron microscopy imaging witnessed the transition from crystalline to quasicrystalline structure as the size of the Pt nanoparticles was reduced to 1 nm. The results highlighted the important impact of size-induced oxidation state of Pt nanoparticles on catalytic selectivity as well as activity in gas-phase methanol oxidation reactions. PMID:23701488