WorldWideScience

Sample records for coal-derived synthesis gas

  1. Biological upgrading of coal-derived synthesis gas: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barik, S.; Johnson, E.R.; Ko, C.W.; Clausen, E.C.; Gaddy, J.L.

    1986-10-01

    The technical feasibility of the biological conversion of coal synthesis gas to methane has been demonstrated in the University of Arkansas laboratories. Cultures of microorganisms have been developed which achieve total conversion in the water gas shift and methanation reactions in either mixed or pure cultures. These cultures carry out these conversions at ordinary temperatures and pressures, without sulfur toxicity. Several microorganisms have been identified as having commercial potential for producing methane. These include a mixed culture of unidentified bacteria; P. productus which produces acetate, a methane precursor; and Methanothrix sp., which produces methane from acetate. These cultures have been used in mixed reactors and immobilized cell reactors to achieve total CO and H/sub 2/ conversion in a retention time of less than two hours, quite good for a biological reactor. Preliminary economic projections indicate that a biological methanation plant with a size of 5 x 10/sup 10/ Btu/day can be economically attractive. 42 refs., 26 figs., 86 tabs.

  2. SYNTHESIS OF METHACRYLATES FROM COAL-DERIVED SYNGAS

    Energy Technology Data Exchange (ETDEWEB)

    Jang, B.W.L.; Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Colberg, R.D.; Choi, G.N.

    1999-12-01

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel have developed a novel process for synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the US Department of Energy/Fossil Energy Technology Center (DOE/FETC). This project has resulted in five US patents (four already published and one pending publication). It has served as the basis for the technical and economic assessment of the production of this high-volume intermediate from coal-derived synthesis gas. The three-step process consists of the synthesis of a propionate from ethylene carbonylation using coal-derived CO, condensation of the propionate with formaldehyde to form methacrylic acid (MAA); and esterification of MAA with methanol to yield MMA. The first two steps, propionate synthesis and condensation catalysis, are the key technical challenges and the focus of the research presented here.

  3. The economic production of alcohol fuels from coal-derived synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, E.L.; Dadyburjor, D.B.; Yang, R.Y.K. [West Virginia Univ., Morgantown, WV (United States)] [and others

    1995-12-31

    The objectives of this project are to discover, (1) study and evaluate novel heterogeneous catalytic systems for the production of oxygenated fuel enhancers from synthesis gas. Specifically, alternative methods of preparing catalysts are to be investigated, and novel catalysts, including sulfur-tolerant ones, are to be pursued. (Task 1); (2) explore, analytically and on the bench scale, novel reactor and process concepts for use in converting syngas to liquid fuel products. (Task 1); (3) simulate by computer the most energy efficient and economically efficient process for converting coal to energy, with primary focus on converting syngas to fuel alcohols. (Task 2); (4) develop on the bench scale the best holistic combination of chemistry, catalyst, reactor and total process configuration integrated with the overall coal conversion process to achieve economic optimization for the conversion of syngas to liquid products within the framework of achieving the maximum cost effective transformation of coal to energy equivalents. (Tasks 1 and 2); and (5) evaluate the combustion, emission and performance characteristics of fuel alcohols and blends of alcohols with petroleum-based fuels. (Task 2)

  4. The economical production of alcohol fuels from coal-derived synthesis gas. Quarterly technical progress report Number 8, 1 July, 1993--30 September, 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    Task 1, the preparation of catalyst materials, is proceeding actively. At WVU, catalysts based on Mo are being prepared using a variety of approaches to alter the oxidation state and environment of the Mo. At UCC and P, copper-based zinc chromite spinel catalysts will be prepared and tested. The modeling of the alcohol-synthesis reaction in a membrane reactor is proceeding actively. Under standard conditions, pressure drop in the membrane reactor has been shown to be negligible. In Task 2, base case designs had previously been completed with a Texaco gasifier. Now, similar designs have been completed using the Shell gasifier. A comparison of the payback periods or production cost of these plants shows significant differences among the base cases. However, a natural gas only design, prepared for comparison purposes, gives a lower payback period or production cost. Since the alcohol synthesis portion of the above processes is the same, the best way to make coal-derived higher alcohols more attractive economically than natural gas-derived higher alcohols is by making coal-derived syngas less expensive than natural gas-derived syngas. The maximum economically feasible capacity for a higher alcohol plant from coal-derived syngas appears to be 32 MM bbl/yr. This is based on consideration of regional coal supply in the eastern US, coal transportation, and regional product demand. The benefits of economics of scale are illustrated for the base case designs. A value for higher alcohol blends has been determined by appropriate combination of RVP, octane number, and oxygen content, using MTBE as a reference. This analysis suggests that the high RVP of methanol in combination with its higher water solubility make higher alcohols more valuable than methanol.

  5. The economical production of alcohol fuels from coal-derived synthesis gas. Quarterly technical progress report No. 4, July 1, 1992--September 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    A base case flow sheet for the production of higher alcohols from coal derived synthesis gas has been completed, including an economic analysis. The details of the flow sheet and economics are in Appendix 1. The pay back period for the capital investment for the plant has been calculated as a function of the market price of the product, and this figure is also shown as Figure I in Appendix 1. The estimated installed cost is almost $500 MM, and the estimated annual operating cost is $64 MM. At a price in the vicinity of $1.00/gal for the alcohol product, the pay back period for construction of the plant is four years. These values should be considered preliminary, since many of the capital costs were obtained from other paper studies sponsored by DOE and TVA and very few values could be found from actual plants which were built. This issue is currently being addressed. The most expensive capital costs were found to be the gasifier, the cryogenic air separation plant, the steam/power generation plant and the acid gas/sulfur removal processes taken as a whole. It is planned to focus attention on alternatives to the base case. The problem is that it is less expensive to make syngas from natural gas. Therefore, it is essential to reduce the cost of syngas from coal. This is where the energy park concept becomes important. In order for this process to be economical (at current market and political conditions) a method must be found to reduce the cost of syngas manufacture either by producing energy or by-products. Energy is produced in the base case, but the amount and method has not been optimized. The economic arguments for this concept are detailed in Appendix 2.

  6. DEVELOPMENT OF NOVEL CERAMIC NANOFILM-FIBER INTEGRATED OPTICAL SENSORS FOR RAPID DETECTION OF COAL DERIVED SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Junhang Dong; Hai Xiao; Xiling Tang; Hongmin Jiang; Kurtis Remmel; Amardeep Kaur

    2012-09-30

    The overall goal of this project is to conduct fundamental studies on advanced ceramic materials and fiber optic devices for developing new types of high temperature (>500{degree}C) fiber optic chemical sensors (FOCS) for monitoring fossil (mainly coal) and biomass derived gases in power plants. The primary technical objective is to investigate and demonstrate the nanocrystalline doped-ceramic thin film enabled FOCS that possess desired stability, sensitivity and selectivity for in-situ, rapid gas detection in the syngas streams from gasification and combustion flue gases. This report summarizes research works of two integrated parts: (1) development of metal oxide solid thin films as sensing materials for detection and measurement of important gas components relevant to the coal- and biomass-derived syngas and combustion gas streams at high temperatures; and (2) development of fiber optic devices that are potentially useful for constructing FOCS in combination with the solid oxide thin films identified in this program.

  7. Evaluation of catalytic combustion of actual coal-derived gas

    Science.gov (United States)

    Blanton, J. C.; Shisler, R. A.

    1982-01-01

    The combustion characteristics of a Pt-Pl catalytic reactor burning coal-derived, low-Btu gas were investigated. A large matrix of test conditions was explored involving variations in fuel/air inlet temperature and velocity, reactor pressure, and combustor exit temperature. Other data recorded included fuel gas composition, reactor temperatures, and exhaust emissions. Operating experience with the reactor was satisfactory. Combustion efficiencies were quite high (over 95 percent) over most of the operating range. Emissions of NOx were quite high (up to 500 ppm V and greater), owing to the high ammonia content of the fuel gas.

  8. Air extraction in gas turbines burning coal-derived gas

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tah-teh; Agrawal, A.K.; Kapat, J.S.

    1993-11-01

    In the first phase of this contracted research, a comprehensive investigation was performed. Principally, the effort was directed to identify the technical barriers which might exist in integrating the air-blown coal gasification process with a hot gas cleanup scheme and the state-of-the-art, US made, heavy-frame gas turbine. The guiding rule of the integration is to keep the compressor and the expander unchanged if possible. Because of the low-heat content of coal gas and of the need to accommodate air extraction, the combustor and perhaps, the flow region between the compressor exit and the expander inlet might need to be modified. In selecting a compressed air extraction scheme, one must consider how the scheme affects the air supply to the hot section of the turbine and the total pressure loss in the flow region. Air extraction must preserve effective cooling of the hot components, such as the transition pieces. It must also ensure proper air/fuel mixing in the combustor, hence the combustor exit pattern factor. The overall thermal efficiency of the power plant can be increased by minimizing the total pressure loss in the diffusers associated with the air extraction. Therefore, a study of airflow in the pre- and dump-diffusers with and without air extraction would provide information crucial to attaining high-thermal efficiency and to preventing hot spots. The research group at Clemson University suggested using a Griffith diffuser for the prediffuser and extracting air from the diffuser inlet. The present research establishes that the analytically identified problems in the impingement cooling flow are factual. This phase of the contracted research substantiates experimentally the advantage of using the Griffith diffuser with air extraction at the diffuser inlet.

  9. Moderate temperature gas purification system: Application to high calorific coal-derived fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, M.; Shirai, H.; Nunokawa, M. [Central Research Institute of Electric Power Industry, Kanagawa (Japan)

    2008-01-15

    Simultaneous removal of dust, alkaline and alkaline-earth metals, halides and sulfur compounds is required to enlarge application of coal-derived gas to the high-temperature fuel cells and the fuel synthesis through chemical processing. Because high calorific fuel gas, such as oxygen-blown coal gas, has high carbon monoxide content, high-temperature (above 450{sup o}C) gas purification system is always subjected to the carbon deposition. We suggest moderate temperature (around 300{sup o}C) operation of the gas purification system to avoid the harmful disproportionation reaction and efficient removal of the various contaminants. Because the reaction rate is predominant to the performance of contaminant removal in the moderate temperature gas purification system, we evaluated the chemical removal processes; performance of the removal processes for halides and sulfur compounds was experimentally evaluated. The halide removal process with sodium aluminate sorbent had potential performance at around 300{sup o}C. The sulfur removal process with zinc ferrite sorbent was also applicable to the temperature range, though the reaction kinetics of the sorbent is essential to be approved.

  10. Moderate temperature gas purification system: application to high calorific coal derived fuel

    Energy Technology Data Exchange (ETDEWEB)

    M. Kobayashi; H. Shirai; M. Nunokawa [Central Research Institute of Electric Power Industry (CRIEPI), Kanagawa (Japan)

    2005-07-01

    Simultaneous removal of dust, alkaline and alkaline-earth metals, halides and sulfur compounds is required to enlarge application of coal-derived gas to the high temperature fuel cells and the fuel synthesis through chemical processing. Because high calorific fuel gas, such as oxygen-blown coal gas, has high carbon monoxide content, high temperature gas purification system is always subjected to the carbon deposition and slippage of contaminant of high vapor pressure. It was suggested that moderate temperature operation of the gas purification system is applied to avoid the harmful disproportionation reaction and efficient removal of the various contaminants. To establish the moderate temperature gas purification system, the chemical-removal processes where the reaction rate is predominant to the performance of contaminant removal should be evaluated. Performance of the removal processes for halides and sulfur compounds were experimentally evaluated. The halide removal process with sodium based sorbent had potential good performance at around 300{sup o}C. The sulfur removal process was also applicable to the temperature range, although the improvement of the sulfidation reaction rate is considered to be essential. 11 refs., 8 figs., 1 tab.

  11. Synthesis of acrylates and methacrylates from coal-derived syngas

    Energy Technology Data Exchange (ETDEWEB)

    Spivey, J.J.; Gogate, M.R.; Jang, B.W.L. [Bechtel, San Francisco, CA (United States)] [and others

    1995-12-31

    Acrylates and methacrylates are among the most widely used chemical intermediates in the world. One of the key chemicals of this type is methyl methacrylate. Of the 4 billion pounds produced each year, roughly 85% is made using the acetone-cyanohydrin process, which requires handling of large quantities of hydrogen cyanide and produces ammonium sulfate wastes that pose an environmental disposal challenge. The U.S. Department of Energy and Eastman Chemical Company are sharing the cost of research to develop an alternative process for the synthesis of methyl methacrylate from syngas. Research Triangle Institute is focusing on the synthesis and testing of active catalysts for the condensation reactions, and Bechtel is analyzing the costs to determine the competitiveness of several process alternatives. Results thus far show that the catalysts for the condensation of formaldehyde and the propionate are key to selectively producing the desired product, methacrylic acid, with a high yield. These condensation catalysts have both acid and base functions and the strength and distribution of these acid-base sites controls the product selectivity and yield.

  12. NOVEL SLURRY PHASE DIESEL CATALYSTS FOR COAL-DERIVED SYNGAS

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Dragomir B. Bukur; Dr. Ketil Hanssen; Alec Klinghoffer; Dr. Lech Nowicki; Patricia O' Dowd; Dr. Hien Pham; Jian Xu

    2001-01-07

    This report describes research conducted to support the DOE program in novel slurry phase catalysts for converting coal-derived synthesis gas to diesel fuels. The primary objective of this research program is to develop attrition resistant catalysts that exhibit high activities for conversion of coal-derived syngas.

  13. THE ECONOMICAL PRODUCTION OF ALCOHOL FUELS FROM COAL-DERIVED SYNTHESIS GAS. Includes quarterly technical progress report No.25 from 10/01/1997-12/31/1997, and quarterly technical progress report No.26 from 01/01/1998-03/31/1998; FINAL

    International Nuclear Information System (INIS)

    1999-01-01

    This project was divided into two parts. One part evaluated possible catalysts for producing higher-alcohols (C(sub 2) to C(sub 5+)) as fuel additives. The other part provided guidance by looking both at the economics of mixed-alcohol production from coal-derived syngas and the effect of higher alcohol addition on gasoline octane and engine performance. The catalysts studied for higher-alcohol synthesis were molybdenum sulfides promoted with potassium. The best catalysts produced alcohols at a rate of 200 g/kg of catalyst/h. Higher-alcohol selectivity was over 40%. The hydrocarbon by-product was less than 20%. These catalysts met established success criteria. The economics for mixed alcohols produced from coal were poor compared to mixed alcohols produced from natural gas. Syngas from natural gas was always less expensive than syngas from coal. Engine tests showed that mixed alcohols added to gasoline significantly improved fuel quality. Mixed-alcohols as produced by our catalysts enhanced gasoline octane and decreased engine emissions. Mixed-alcohol addition gave better results than adding individual alcohols as had been done in the 1980's when some refiners added methanol or ethanol to gasoline

  14. THE ECONOMICAL PRODUCTION OF ALCOHOL FUELS FROM COAL-DERIVED SYNTHESIS GAS. Includes quarterly technical progress report No.25 from 10/01/1997-12/31/1997, and quarterly technical progress report No.26 from 01/01/1998-03/31/1998

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-03-01

    This project was divided into two parts. One part evaluated possible catalysts for producing higher-alcohols (C{sub 2} to C{sub 5+}) as fuel additives. The other part provided guidance by looking both at the economics of mixed-alcohol production from coal-derived syngas and the effect of higher alcohol addition on gasoline octane and engine performance. The catalysts studied for higher-alcohol synthesis were molybdenum sulfides promoted with potassium. The best catalysts produced alcohols at a rate of 200 g/kg of catalyst/h. Higher-alcohol selectivity was over 40%. The hydrocarbon by-product was less than 20%. These catalysts met established success criteria. The economics for mixed alcohols produced from coal were poor compared to mixed alcohols produced from natural gas. Syngas from natural gas was always less expensive than syngas from coal. Engine tests showed that mixed alcohols added to gasoline significantly improved fuel quality. Mixed-alcohols as produced by our catalysts enhanced gasoline octane and decreased engine emissions. Mixed-alcohol addition gave better results than adding individual alcohols as had been done in the 1980's when some refiners added methanol or ethanol to gasoline.

  15. Pd/activated carbon sorbents for mid-temperature capture of mercury from coal-derived fuel gas.

    Science.gov (United States)

    Li, Dekui; Han, Jieru; Han, Lina; Wang, Jiancheng; Chang, Liping

    2014-07-01

    Higher concentrations of Hg can be emitted from coal pyrolysis or gasification than from coal combustion, especially elemental Hg. Highly efficient Hg removal technology from coal-derived fuel gas is thus of great importance. Based on the very excellent Hg removal ability of Pd and the high adsorption abilities of activated carbon (AC) for H₂S and Hg, a series of Pd/AC sorbents was prepared by using pore volume impregnation, and their performance in capturing Hg and H₂S from coal-derived fuel gas was investigated using a laboratory-scale fixed-bed reactor. The effects of loading amount, reaction temperature and reaction atmosphere on Hg removal from coal-derived fuel gas were studied. The sorbents were characterized by N₂ adsorption, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results indicated that the efficiency of Hg removal increased with the increasing of Pd loading amount, but the effective utilization rate of the active component Pd decreased significantly at the same time. High temperature had a negative influence on the Hg removal. The efficiency of Hg removal in the N₂-H₂S-H₂-CO-Hg atmosphere (simulated coal gas) was higher than that in N₂-H₂S-Hg and N₂-Hg atmospheres, which showed that H₂ and CO, with their reducing capacity, could benefit promote the removal of Hg. The XPS results suggested that there were two different ways of capturing Hg over sorbents in N₂-H₂S-Hg and N₂-Hg atmospheres. Copyright © 2014. Published by Elsevier B.V.

  16. PALLADIUM/COPPER ALLOY COMPOSITE MEMBRANES FOR HIGH TEMPERATURE HYDROGEN SEPARATION FROM COAL-DERIVED GAS STREAMS; F

    International Nuclear Information System (INIS)

    J. Douglas Way; Robert L. McCormick

    2001-01-01

    Recent advances have shown that Pd-Cu composite membranes are not susceptible to the mechanical, embrittlement, and poisoning problems that have prevented widespread industrial use of Pd for high temperature H(sub 2) separation. These membranes consist of a thin ((approx)10(micro)m) film of metal deposited on the inner surface of a porous metal or ceramic tube. Based on preliminary results, thin Pd(sub 60)Cu(sub 40) films are expected to exhibit hydrogen flux up to ten times larger than commercial polymer membranes for H(sub 2) separation, and resist poisoning by H(sub 2)S and other sulfur compounds typical of coal gas. Similar Pd-membranes have been operated at temperatures as high as 750 C. The overall objective of the proposed project is to demonstrate the feasibility of using sequential electroless plating to fabricate Pd(sub 60)Cu(sub 40) alloy membranes on porous supports for H(sub 2) separation. These following advantages of these membranes for processing of coal-derived gas will be demonstrated: High H(sub 2) flux; Sulfur tolerant, even at very high total sulfur levels (1000 ppm); Operation at temperatures well above 500 C; and Resistance to embrittlement and degradation by thermal cycling. The proposed research plan is designed to providing a fundamental understanding of: Factors important in membrane fabrication; Optimization of membrane structure and composition; Effect of temperature, pressure, and gas composition on H(sub 2) flux and membrane selectivity; and How this membrane technology can be integrated in coal gasification-fuel cell systems

  17. Integrated Warm Gas Multicontaminant Cleanup Technologies for Coal-Derived Syngas

    Energy Technology Data Exchange (ETDEWEB)

    Turk, Brian; Gupta, Raghubir; Sharma, Pradeepkumar; Albritton, Johnny; Jamal, Aqil

    2010-09-30

    One of the key obstacles for the introduction of commercial gasification technology for the production of power with Integrated Gasification Combined Cycle (IGCC) plants or the production of value added chemicals, transportation fuels, and hydrogen has been the cost of these systems. This situation is particularly challenging because the United States has ample coal resources available as raw materials and effective use of these raw materials could help us meet our energy and transportation fuel needs while significantly reducing our need to import oil. One component of the cost of these systems that faces strong challenges for continuous improvement is removing the undesirable components present in the syngas. The need to limit the increase in cost of electricity to < 35% for new coal-based power plants which include CO{sub 2} capture and sequestration addresses both the growing social concern for global climate change resulting from the emission of greenhouse gas and in particular CO{sub 2} and the need to control cost increases to power production necessary to meet this social objective. Similar improvements to technologies for trace contaminants are getting similar pressure to reduce environmental emissions and reduce production costs for the syngas to enable production of chemicals from coal that is cost competitive with oil and natural gas. RTI, with DOE/NETL support, has been developing sorbent technologies that enable capture of trace contaminants and CO{sub 2} at temperatures above 400 °F that achieve better capture performance, lower costs and higher thermal efficiency. This report describes the specific work of sorbent development for mercury (Hg), arsenic (As), selenium (Se), cadmium (Cd), and phosphorous (P) and CO{sub 2} removal. Because the typical concentrations of Hg, As, Se, Cd, and P are less than 10 ppmv, the focus has been on single-use sorbents with sufficient capacity to ensure replacement costs are cost effective. The research in this

  18. Alternative Fuels and Chemicals from Synthesis Gas

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1998-12-02

    The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

  19. Alternative fuels and chemicals from synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    1998-08-01

    The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

  20. ALTERNATIVE FUELS AND CHEMICALS FROM SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    1999-01-01

    The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

  1. Alternative Fuels and Chemicals From Synthesis Gas

    Energy Technology Data Exchange (ETDEWEB)

    none

    1998-07-01

    The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

  2. Partial Oxidation Gas Turbine for Power and Hydrogen Co-Production from Coal-Derived Fuel in Industrial Applications

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Rabovitser

    2009-06-30

    The report presents a feasibility study of a new type of gas turbine. A partial oxidation gas turbine (POGT) shows potential for really high efficiency power generation and ultra low emissions. There are two main features that distinguish a POGT from a conventional gas turbine. These are associated with the design arrangement and the thermodynamic processes used in operation. A primary design difference of the POGT is utilization of a non?catalytic partial oxidation reactor (POR) in place of a conventional combustor. Another important distinction is that a much smaller compressor is required, one that typically supplies less than half of the air flow required in a conventional gas turbine. From an operational and thermodynamic point of view a key distinguishing feature is that the working fluid, fuel gas provided by the OR, has a much higher specific heat than lean combustion products and more energy per unit mass of fluid can be extracted by the POGT expander than in the conventional systems. The POGT exhaust stream contains unreacted fuel that can be combusted in different bottoming ycle or used as syngas for hydrogen or other chemicals production. POGT studies include feasibility design for conversion a conventional turbine to POGT duty, and system analyses of POGT based units for production of power solely, and combined production of power and yngas/hydrogen for different applications. Retrofit design study was completed for three engines, SGT 800, SGT 400, and SGT 100, and includes: replacing the combustor with the POR, compressor downsizing for about 50% design flow rate, generator replacement with 60 90% ower output increase, and overall unit integration, and extensive testing. POGT performances for four turbines with power output up to 350 MW in POGT mode were calculated. With a POGT as the topping cycle for power generation systems, the power output from the POGT ould be increased up to 90% compared to conventional engine keeping hot section temperatures

  3. Gas Phase Nanoparticle Synthesis

    Science.gov (United States)

    Granqvist, Claes; Kish, Laszlo; Marlow, William

    This book deals with gas-phase nanoparticle synthesis and is intended for researchers and research students in nanomaterials science and engineering, condensed matter physics and chemistry, and aerosol science. Gas-phase nanoparticle synthesis is instrumental to nanotechnology - a field in current focus that raises hopes for environmentally benign, resource-lean manufacturing. Nanoparticles can be produced by many physical, chemical, and even biological routes. Gas-phase synthesis is particularly interesting since one can achieve accurate manufacturing control and hence industrial viability.

  4. Warm Cleanup of Coal-Derived Syngas: Multicontaminant Removal Process Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Spies, Kurt A.; Rainbolt, James E.; Li, Xiaohong S.; Braunberger, Beau; Li, Liyu; King, David L.; Dagle, Robert A.

    2017-02-15

    Warm cleanup of coal- or biomass-derived syngas requires sorbent and catalytic beds to protect downstream processes and catalysts from fouling. Sulfur is particularly harmful because even parts-per-million amounts are sufficient to poison downstream synthesis catalysts. Zinc oxide (ZnO) is a conventional sorbent for sulfur removal; however, its operational performance using real gasifier-derived syngas and in an integrated warm cleanup process is not well reported. In this paper, we report the optimal temperature for bulk desulfurization to be 450oC, while removal of sulfur to parts-per-billion levels requires a lower temperature of approximately 350oC. Under these conditions, we found that sulfur in the form of both hydrogen sulfide and carbonyl sulfide could be absorbed equally well using ZnO. For long-term operation, sorbent regeneration is desirable to minimize process costs. Over the course of five sulfidation and regeneration cycles, a ZnO bed lost about a third of its initial sulfur capacity, however sorbent capacity stabilized. Here, we also demonstrate, at the bench-scale, a process and materials used for warm cleanup of coal-derived syngas using five operations: 1) Na2CO3 for HCl removal, 2) regenerable ZnO beds for bulk sulfur removal, 3) a second ZnO bed for trace sulfur removal, 4) a Ni-Cu/C sorbent for multi-contaminant inorganic removal, and 5) a Ir-Ni/MgAl2O4 catalyst employed for ammonia decomposition and tar and light hydrocarbon steam reforming. Syngas cleanup was demonstrated through successful long-term performance of a poison-sensitive, Cu-based, water-gas-shift catalyst placed downstream of the cleanup process train. The tar reformer is an important and necessary operation with this particular gasification system; its inclusion was the difference between deactivating the water-gas catalyst with carbon deposition and successful 100-hour testing using 1 LPM of coal-derived syngas.

  5. 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

  6. Effects of coal-derived trace species on performance of molten carbonate fuel cells. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    The Carbonate Fuel Cell is a very promising option for highly efficient generation of electricity from many fuels. If coal-gas is to be used, the interactions of coal-derived impurities on various fuel cell components need to be understood. Thus the effects on Carbonate Fuel Cell performance due to ten different coal-derived contaminants viz., NH{sub 3}, H{sub 2}S, HC{ell}, H{sub 2}Se, AsH{sub 3}, Zn, Pb, Cd, Sn, and Hg, have been studied at Energy Research Corporation. Both experimental and theoretical evaluations were performed, which have led to mechanistic insights and initial estimation of qualitative tolerance levels for each species individually and in combination with other species. The focus of this study was to investigate possible coal-gas contaminant effects on the anode side of the Carbonate Fuel Cell, using both out-of-cell thermogravimetric analysis by isothermal TGA, and fuel cell testing in bench-scale cells. Separate experiments detailing performance decay in these cells with high levels of ammonia contamination (1 vol %) and with trace levels of Cd, Hg, and Sn, have indicated that, on the whole, these elements do not affect carbonate fuel cell performance. However, some performance decay may result when a number of the other six species are present, singly or simultaneously, as contaminants in fuel gas. In all cases, tolerance levels have been estimated for each of the 10 species and preliminary models have been developed for six of them. At this stage the models are limited to isothermal, benchscale (300 cm{sup 2} size) single cells. The information obtained is expected to assist in the development of coal-gas cleanup systems, while the contaminant performance effects data will provide useful basic information for modeling fuel cell endurance in conjunction with integrated gasifier/fuel-cell systems (IGFC).

  7. Effects of coal-derived trace species on performance of molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    The Carbonate Fuel Cell is a very promising option for highly efficient generation of electricity from many fuels. If coal-gas is to be used, the interactions of coal-derived impurities on various fuel cell components need to be understood. Thus the effects on Carbonate Fuel Cell performance due to ten different coal-derived contaminants viz., NH{sub 3}, H{sub 2}S, HC{ell}, H{sub 2}Se, AsH{sub 3}, Zn, Pb, Cd, Sn, and Hg, have been studied at Energy Research Corporation. Both experimental and theoretical evaluations were performed, which have led to mechanistic insights and initial estimation of qualitative tolerance levels for each species individually and in combination with other species. The focus of this study was to investigate possible coal-gas contaminant effects on the anode side of the Carbonate Fuel Cell, using both out-of-cell thermogravimetric analysis by isothermal TGA, and fuel cell testing in bench-scale cells. Separate experiments detailing performance decay in these cells with high levels of ammonia contamination (1 vol %) and with trace levels of Cd, Hg, and Sn, have indicated that, on the whole, these elements do not affect carbonate fuel cell performance. However, some performance decay may result when a number of the other six species are present, singly or simultaneously, as contaminants in fuel gas. In all cases, tolerance levels have been estimated for each of the 10 species and preliminary models have been developed for six of them. At this stage the models are limited to isothermal, benchscale (300 cm{sup 2} size) single cells. The information obtained is expected to assist in the development of coal-gas cleanup systems, while the contaminant performance effects data will provide useful basic information for modeling fuel cell endurance in conjunction with integrated gasifier/fuel-cell systems (IGFC).

  8. Improvement of hydrodenitrogenation (HDN) in co-refining of coal-derived liquid and petroleum fraction

    Energy Technology Data Exchange (ETDEWEB)

    Machida, M.; Ono, S. [Idemitsu Kosan Co. Ltd., Tokyo (Japan); Hattori, H. [Hokkaido University, Sapporo (Japan). Center for Advanced Research of Energy Technology

    1997-09-01

    The improvement in hydrodenitrogenation (HDN) of coal-derived liquids by co-refining with a petroleum fraction results principally from lowering the nitrogen content of the feedstock (coal-derived liquid) by blending with a nitrogen-free petroleum fraction. Effects of different fractions of coal-derived liquids on HDN and hydrodeoxygenation (HDO) were also examined. The HDN improvement by co-refining could be interpreted in terms of Langmuir-Hinshelwood mechanism. 38 refs., 3 figs., 3 tabs.

  9. Generation of synthesis gas by partial oxidation of natural gas in a gas turbine

    NARCIS (Netherlands)

    Cornelissen, R.; Tober, E.; Kok, Jacobus B.W.; van der Meer, Theodorus H.

    2006-01-01

    The application of partial oxidation in a gas turbine (PO-GT) in the production of synthesis gas for methanol production is explored. In PO-GT, methane is compressed, preheated, partial oxidized and expanded. For the methanol synthesis a 12% gain in thermal efficiency has been calculated for the

  10. DEVELOPMENT OF ALTERNATIVE FUELS AND CHEMICALS FROM SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Peter J. Tijrn

    2003-05-31

    This Final Report for Cooperative Agreement No. DE-FC22-95PC93052, the ''Development of Alternative Fuels and Chemicals from Synthesis Gas,'' was prepared by Air Products and Chemicals, Inc. (Air Products), and covers activities from 29 December 1994 through 31 July 2002. The overall objectives of this program were to investigate potential technologies for the conversion of synthesis gas (syngas), a mixture primarily of hydrogen (H{sub 2}) and carbon monoxide (CO), to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at the LaPorte, Texas Alternative Fuels Development Unit (AFDU). Laboratory work was performed by Air Products and a variety of subcontractors, and focused on the study of the kinetics of production of methanol and dimethyl ether (DME) from syngas, the production of DME using the Liquid Phase Dimethyl Ether (LPDME{trademark}) Process, the conversion of DME to fuels and chemicals, and the production of other higher value products from syngas. Four operating campaigns were performed at the AFDU during the performance period. Tests of the Liquid Phase Methanol (LPMEOH{trademark}) Process and the LPDME{trademark} Process were made to confirm results from the laboratory program and to allow for the study of the hydrodynamics of the slurry bubble column reactor (SBCR) at a significant engineering scale. Two campaigns demonstrated the conversion of syngas to hydrocarbon products via the slurry-phase Fischer-Tropsch (F-T) process. Other topics that were studied within this program include the economics of production of methyl tert-butyl ether (MTBE), the identification of trace components in coal-derived syngas and the means to economically remove these species, and the study of systems for separation of wax from catalyst in the F-T process. The work performed under this Cooperative Agreement has continued to promote the development of technologies that use clean syngas produced

  11. Method and apparatus for producing synthesis gas

    Science.gov (United States)

    Hemmings, John William; Bonnell, Leo; Robinson, Earl T.

    2010-03-03

    A method and apparatus for reacting a hydrocarbon containing feed stream by steam methane reforming reactions to form a synthesis gas. The hydrocarbon containing feed is reacted within a reactor having stages in which the final stage from which a synthesis gas is discharged incorporates expensive high temperature materials such as oxide dispersed strengthened metals while upstream stages operate at a lower temperature allowing the use of more conventional high temperature alloys. Each of the reactor stages incorporate reactor elements having one or more separation zones to separate oxygen from an oxygen containing feed to support combustion of a fuel within adjacent combustion zones, thereby to generate heat to support the endothermic steam methane reforming reactions.

  12. Adsorption of ultra-low concentration malodorous substances using coal-derived granular activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Urano, K.; Maeda, T.; Yamashita, H.; Hagio, S.; Arioka, A.

    1986-01-01

    The experimental adsorption is reported of diosmin and 2-methylisoborneol using two types of coal-derived granular activated carbon and one derived from coconut husk. It was discovered that carbons with more pores below 15 angstroms in size gave a higher equilibrium adsorption of malodorous substances at mg/l concentrations. It was also found that the coal-derived materials, which contained more pores larger than 15 angstroms, gave faster adsorption. Given that the coal-derived carbons have a longer service life, it is concluded that they are suitable for use in full-scale adsorption plant where contact times are short. 3 references, 5 figures, 5 tables.

  13. Application of zeolite-based catalyst to hydrocracking of coal-derived liquids

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, H.; Sato, T.; Yoshimura, Y.; Hinata, A.; Yoshitomi, S.; Castillo Mares, A.; Nishijima, A. (National Chemical Laboratory for Industry, Tsukuba (Japan))

    1990-06-01

    Y-zeolite supported catalysts were applied to the hydrocracking of coal-derived liquids. By the introduction of two-stage upgrading consisting of hydrotreating and hydrocracking, Wandoan coal-derived middle distillate was hydrocracked over Ni-Mo/Y-zeolite, producing a high gasoline fraction yield. Zeolite supported catalysts gave little hydrocracked compounds in the hydroprocessing of coal-derived heavy oils, even after hydrotreatment. The reaction inhibitors which seriously poison the active sites of zeolites were found to be small nitrogen-containing molecules. In the hydroprocessing of coal-derived heavy oils, zeolite supported catalysts were inferior to alumina supported catalysts. This is due to the high hydrocracking but low hydrogenation activity of zeolite supported catalysts. 22 refs., 5 figs., 11 tabs.

  14. Investigation of sulfur-polycyclic aromatic hydrocarbon in coal derived tars of pyrolysis and hydropyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.; Li, B.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). State Key Laboratory of Coal Conversion

    1999-07-01

    A study was undertaken to characterize sulphur forms in coal derived tars from pyrolysis and hydropyrolysis of bituminous coal and lignite. The pyrolysis tars were analyzed for content of polycyclic aromatic sulfur hydrocarbons (PASH). 5 refs., 3 figs., 3 tabs.

  15. Performance effects of coal-derived contaminants on the carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Pigeaud, A. [Energy Research Corp., Danbury, CT (United States); Wilemski, G. [Physical Sciences, Inc., Andover, MA (United States)

    1993-05-01

    Coal-derived contaminant studies have been pursued at ERC since the early 1980`s when the pace of carbonate fuel cell development began to markedly increase. Initial work was concerned with performance effects on laboratory and bench-scale carbonate fuel cells primarily due to sulfur compounds. Results have now also been obtained with respect to nine additional coal-gas contaminants, including volatile trace metal species. Thermochemical calculations, out-of-cell experiments, and cell performance as well as endurance testshave recently been conducted which have involved the following species: NH{sub 3}, H{sub 2}S [COS], HCl, AsH{sub 3}[As{sub 2}(v)], Zn(v), Pb(v), Cd(v), H{sub 2} Se, Hg(v), Sn(v). Employing thermochemically calculated results, thermogravimetric (TGA) and pre-, and post-test analytical data as well as fuel cell performance observations, it has been shown that there are four main mechanisms of contaminant interaction with the carbonate fuel cell. These have been formulated into performance models for six significant contaminant species, thus providing long-term endurance estimations.

  16. Performance effects of coal-derived contaminants on the carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Pigeaud, A. (Energy Research Corp., Danbury, CT (United States)); Wilemski, G. (Physical Sciences, Inc., Andover, MA (United States))

    1993-01-01

    Coal-derived contaminant studies have been pursued at ERC since the early 1980's when the pace of carbonate fuel cell development began to markedly increase. Initial work was concerned with performance effects on laboratory and bench-scale carbonate fuel cells primarily due to sulfur compounds. Results have now also been obtained with respect to nine additional coal-gas contaminants, including volatile trace metal species. Thermochemical calculations, out-of-cell experiments, and cell performance as well as endurance testshave recently been conducted which have involved the following species: NH[sub 3], H[sub 2]S [COS], HCl, AsH[sub 3][As[sub 2](v)], Zn(v), Pb(v), Cd(v), H[sub 2] Se, Hg(v), Sn(v). Employing thermochemically calculated results, thermogravimetric (TGA) and pre-, and post-test analytical data as well as fuel cell performance observations, it has been shown that there are four main mechanisms of contaminant interaction with the carbonate fuel cell. These have been formulated into performance models for six significant contaminant species, thus providing long-term endurance estimations.

  17. Internal Combustion Engine Powered by Synthesis Gas from Pyrolysed Plastics

    Directory of Open Access Journals (Sweden)

    Chríbik Andrej

    2016-07-01

    Full Text Available The article discusses the application of synthesis gas from pyrolysis of plastics in petrol engine. The appropriate experimental measurements were performed on a combustion engine LGW 702 designated for micro-cogeneration unit. The power parameters, economic parameters in term of brake specific fuel consumption, and internal parameters of the engine were compared to the engine running on the reference fuel - natural gas and synthesis gas. Burning synthesis gas leads to decreased performance by about 5% and to increased mass hourly consumption by 120 %. In terms of burning, synthesis gas has similar properties as natural gas. Compared with [5] a more detailed study has been prepared on the effects of angle of spark advance on the engine torque, giving more detailed assessment of engine cycle variability and considering specification of start and end of combustion in the logarithm p-V diagram.

  18. Competitive reaction in hydrodenitrogenation and hydrodeoxygenation of coal-derived naphtha

    Energy Technology Data Exchange (ETDEWEB)

    Machida, M. (Idemitsu Kosan Co. Ltd., Tokyo (Japan). Central Research Lab.); Sakao, Y.; Ono, S. (Idemitsu Kosan Co. Ltd., Tokyo (Japan))

    1994-03-01

    The naphtha fraction derived from coal is expected to be one of the most suitable blending stocks for motor gasoline because of its high contents of cyclic hydrocarbons. However, since the contents of nitrogen and oxygen are high in the coal naphtha, the amounts of these elements must be reduced to acceptable levels. In this study, aiming to clarify the hydrodenitrogenation (HDN) and hydrodeoxygenation (HDO) performances of practical feed stocks, HDN and HDO of coal-derived naphtha and its model compounds were examined by using a catalyst Ni-Mo/Al2O3 group. There are tree types of nitrogen compounds, pyridine, pyrrole and aniline, in the coal-derived naphtha. Aniline type nitrogen compounds in the coal-derived naphtha are more resistant to HDN than pyridine type compounds, though aniline is more reactive than pyridine when the reaction is carried out individually. 14 refs., 7 figs., 3 tabs.

  19. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 1: Executive summary. [using coal or coal derived fuels

    Science.gov (United States)

    Corman, J. C.

    1976-01-01

    A data base for the comparison of advanced energy conversion systems for utility applications using coal or coal-derived fuels was developed. Estimates of power plant performance (efficiency), capital cost, cost of electricity, natural resource requirements, and environmental intrusion characteristics were made for ten advanced conversion systems. Emphasis was on the energy conversion system in the context of a base loaded utility power plant. All power plant concepts were premised on meeting emission standard requirements. A steam power plant (3500 psig, 1000 F) with a conventional coal-burning furnace-boiler was analyzed as a basis for comparison. Combined cycle gas/steam turbine system results indicated competitive efficiency and a lower cost of electricity compared to the reference steam plant. The Open-Cycle MHD system results indicated the potential for significantly higher efficiency than the reference steam plant but with a higher cost of electricity.

  20. Upgrading including heteroatom removal from Victorian brown coal-derived liquids

    Energy Technology Data Exchange (ETDEWEB)

    Larkins, F.P.; Youings, J.C.; Jackson, W.R.; Park, D. (University of Tasmania, Hobart, Tasmania (Australia))

    1989-10-01

    It has been shown using model compounds that the hydrodeoxygenation performance of a catalyst is severely inhibited by the presence of nitrogen-containing compounds under conditions of moderate reaction severity. For a low molecular weight coal-derived liquid commercial catalysts were effective for HDO and HDN at 400{degree}C, 10 MPa H{sub 2} for 30 min reaction time. For a coal-derived liquid high in asphaltene commercial catalysts and others prepared and tested in this study were ineffective. Alternative catalysts and hydrotreating conditions of greater severity will be required for such materials to effect acceptable heteroatom removal. 3 refs., 2 figs., 2 tabs.

  1. Alternative fuels and chemicals from synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    1998-12-01

    A DOE/PETC funded study was conducted to examine the use of a liquid phase mixed alcohol synthesis (LPMAS) plant to produce gasoline blending ethers. The LPMAS plant was integrated into three utilization scenarios: a coal fed IGCC power plant, a petroleum refinery using coke as a gasification feedstock, and a standalone natural gas fed partial oxidation plant. The objective of the study was to establish targets for the development of catalysts for the LPMAS reaction. In the IGCC scenario, syngas conversions need only be moderate because unconverted syngas is utilized by the combined cycle system. A once through LPMAS plant achieving syngas conversions in the range of 38--49% was found to be suitable. At a gas hourly space velocity of 5,000 sL/Kg-hr and a methanol:isobutanol selectivity ratio of 1.03, the target catalyst productivity ranges from 370 to 460 g iBuOH/Kg-hr. In the petroleum refinery scenario, high conversions ({approximately}95%) are required to avoid overloading the refinery fuel system with low Btu content unconverted syngas. To achieve these high conversions with the low H{sub 2}/CO ratio syngas, a recycle system was required (because of the limit imposed by methanol equilibrium), steam was injected into the LPMAS reactor, and CO{sub 2} was removed from the recycle loop. At the most economical recycle ratio, the target catalyst productivity is 265 g iBuOH/Kg-hr. In the standalone LPMAS scenario, essentially complete conversions are required to achieve a fuel balanced plant. At the most economical recycle ratio, the target catalyst productivity is 285 g iBuOH/Kg-hr. The economics of this scenario are highly dependent on the cost of the natural gas feedstock and the location of the plant. For all three case scenarios, the economics of a LPMAS plant is marginal at current ether market prices. Large improvements over demonstrated catalyst productivity and alcohol selectivity are required.

  2. Degradation and stabilization of coal derived liquid. (IV). ; Effect of alcohol on coloration of coal derived light oil. Sekitan ekikayu no anteika. (IV). ; Sekitan ekikayu no chakushoku yokusei ni oyobosu alcohol no tenka koka

    Energy Technology Data Exchange (ETDEWEB)

    Ukegawa, K.; Matsumura, A.; Kondo, T. (National Research Institute for Pollution and Resources, Tsukuba (Japan)); TAhara, N. (Nitto Denko Corp., Osaka (Japan)); Nakamura, E. (New Energy and Industrial Technology Development Organization, Tokyo (Japan)); Niki, E. (The University of Tokyo, Tokyo (Japan). Research Center for ADvanced Science and Technology)

    1990-01-20

    In order to improve the color stability of a coal derived light oil, the effect of hydrotreating and various additives has been studied. The color stability has been evaluated through measuring changes in absorbance by flow-cell spectrophotometer. Following results have been obtained: The color stabilities of hydrotreated coal derived light oils were improved remarkably with increasing hydrotreating temperature and pressure. Mild hydrotreating made the color stability of the coal derived light oil much better than the fuel oil, even though the nitrogen removal was very small. Phenolic compounds additives could not improve the color stability of the coal derived light oil. Alcohol, especially methanol, made the coloration rate of the coal derived light oil small to a great extent, on account of hydrogen bonding between methanol and nitrogen compounds in the fuel oil. 4 refs., 4 figs., 3 tabs.

  3. Primary migration of Jurassic coal-derived oil in Santanghu basin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.; Zhong, N.; Ren, D. [China University of Mining and Technology, Beijing (China). Dept of Resource Exploitation Engineering

    2000-11-01

    It is known that the differential evolution of the multiple macerals results in 'oil generation by stage', and that 'early generation, early expulsion' is one of the preconditions for the efficient accumulation of the coal-derived oil. Based upon the study on the evolution of the physical properties, related to the hydrocarbon expulsion, of the Jurassic organic rock in Santanghu basin during the course of maturation, the mechanism of the primary migration of its coal-derived oil was discussed. The rapid loss of the inherent moisture in the organic rock was not accordant with the main generation stage of the coal-derived oil, so it was unrealistic that the oil migrated by dissolution in the expelled water. It is thought that the special forming mechanism of the continuous 'bitumen network' under the condition of over-pressure and an earlier history of primary migration may be essential to the Jurassic coal-derived oil in Santanghu basin. 17 refs., 4 figs.

  4. Newer methods for the characterization of higher molecular mass coal derivatives

    International Nuclear Information System (INIS)

    Bartle, K.D.

    1983-01-01

    Recent developments in a number of areas in the analytical chemistry of higher molecular mass coal derivatives are critically reviewed, viz. supercritical fluid chromatography, size-exclusion chromatography, charge-transfer fractionation, nmr spectroscopy, mass spectrometry and electrochemical analysis. (orig.) [de

  5. Advances in the Partial Oxidation of Methane to Synthesis Gas

    Institute of Scientific and Technical Information of China (English)

    Quanli Zhu; Xutao Zhao; Youquan Deng

    2004-01-01

    The conversion and utilization of natural gas is of significant meaning to the national economy,even to the everyday life of people. However, it has not become a popular industrial process as expected due to the technical obstacles. In the past decades, much investigation into the conversion of methane,predominant component of natural gas, has been carried out. Among the possible routes of methane conversion, the partial oxidation of methane to synthesis gas is considered as an effective and economically feasible one. In this article, a brief review of recent studies on the mechanism of the partial oxidation of methane to synthesis gas together with catalyst development is wherein presented.

  6. Proceedings of the DGMK-conference 'Synthesis gas chemistry'. Authors' manuscripts

    Energy Technology Data Exchange (ETDEWEB)

    Hoenicke, D; Kohlpaintner, C; Luecke, B; Reschetilowski, W [eds.

    2000-07-01

    The main topics of the DGMK-Conference ''Synthesis Gas Chemistry'' were: production of synthesis gas from several educts, new catalysts, Fischer-Tropsch synthesis, hydroformylation, steam reforming and carbonylation.

  7. Forty years of the Weglopochodne Enterprise for Sale of Coal-Derived Products

    Energy Technology Data Exchange (ETDEWEB)

    Pinkowski, Z.

    1986-02-01

    Organizational structure of trade in coal-derived products in Poland from 1945 to 1985 is discussed. Fluctuations of organizational structures reflecting phases of centralization and decentralization of the national economy are analyzed. Coordinating role of the Weglopochodne Enterprise in the coking and chemical industries is stressed. Types of products produced by coking plants in Poland, trade and exports are discussed. Effects of organizational structures on development of coking plants are also discussed (increasing wear of coking plants, insufficient investment etc.). 3 references.

  8. Synthesis gas production via hybrid steam reforming of natural gas and bio-liquids

    OpenAIRE

    Balegedde Ramachandran, P.

    2013-01-01

    This thesis deals with (catalytic) steam reforming of bio-liquids for the production of synthesis gas. Glycerol, both crude from the biodiesel manufacturing and refined, and pyrolysis oil are tested as bio-based feedstocks. Liquid bio-based feeds could be preferred over inhomogeneous fibrous solid biomass because of their logistic advantages, better mineral balance, and better processability. Especially the ease of pressurization, which is required for large scale synthesis gas production, is...

  9. Production of High-Hydrogen Content Coal-Derived Liquids [Part 3 of 3

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Bergin

    2011-03-30

    The primary goal of this project has been to evaluate and compare the effect of the intrinsic differences between cobalt (Co) and iron (Fe) catalysts for Fischer-Tropsch (FT) synthesis using coal-derived syngas. Crude oil, especially heavy, high-sulfur crude, is no longer the appropriate source for the additional, or marginal, amounts of middle-distillate fuels needed to meet growing US and world demand for diesel and jet fuels. Only about 1/3 of the marginal crude oil barrel can be made into diesel and jet fuels. The remaining 2/3 contributes further to global surpluses of by-products. FT can produce these needed marginal, low-sulfur middle-distillate fuels more efficiently, with less environmental impact, and from abundant US domestic resources. Cobalt FT catalyst is more efficient, and less expensive overall, than iron FT catalyst. Mechanisms of cobalt FT catalyst functioning, and poisoning, have been elucidated. Each of these primary findings is amplified by several secondary findings, and these are presented, and verified in detail. The most effective step the United States can take to begin building toward improved long-term national energy security, and to reduce dependence, over time, on imported crude oil from unfriendly and increasingly unstable areas of the world, is to begin producing additional, or marginal amounts of, middle-distillate-type fuels, such as ultralow sulfur diesel (ULSD) and jet fuel (not gasoline) from US domestic resources other than petroleum. FT synthesis of these middle distillate fuels offers the advantage of being able to use abundant and affordable US coal and biomass as the primary feedstocks. Use of the cobalt FT catalyst system has been shown conclusively to be more effective and less expensive than the use of iron FT catalyst with syngas derived from coal, or from coal and biomass combined. This finding is demonstrated in detail for the initial case of a relatively small FT plant of about 2000 barrels per day based upon coal

  10. Production of High-Hydrogen Content Coal-Derived Liquids [Part 2 of 3

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Bergin

    2011-03-30

    The primary goal of this project has been to evaluate and compare the effect of the intrinsic differences between cobalt (Co) and iron (Fe) catalysts for Fischer-Tropsch (FT) synthesis using coal-derived syngas. Crude oil, especially heavy, high-sulfur crude, is no longer the appropriate source for the additional, or marginal, amounts of middle-distillate fuels needed to meet growing US and world demand for diesel and jet fuels. Only about 1/3 of the marginal crude oil barrel can be made into diesel and jet fuels. The remaining 2/3 contributes further to global surpluses of by-products. FT can produce these needed marginal, low-sulfur middle-distillate fuels more efficiently, with less environmental impact, and from abundant US domestic resources. Cobalt FT catalyst is more efficient, and less expensive overall, than iron FT catalyst. Mechanisms of cobalt FT catalyst functioning, and poisoning, have been elucidated. Each of these primary findings is amplified by several secondary findings, and these are presented, and verified in detail. The most effective step the United States can take to begin building toward improved long-term national energy security, and to reduce dependence, over time, on imported crude oil from unfriendly and increasingly unstable areas of the world, is to begin producing additional, or marginal amounts of, middle-distillate-type fuels, such as ultralow sulfur diesel (ULSD) and jet fuel (not gasoline) from US domestic resources other than petroleum. FT synthesis of these middle distillate fuels offers the advantage of being able to use abundant and affordable US coal and biomass as the primary feedstocks. Use of the cobalt FT catalyst system has been shown conclusively to be more effective and less expensive than the use of iron FT catalyst with syngas derived from coal, or from coal and biomass combined. This finding is demonstrated in detail for the initial case of a relatively small FT plant of about 2000 barrels per day based upon coal

  11. Production of High-Hydrogen Content Coal-Derived Liquids [Part 1 of 3

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Bergin

    2011-03-30

    The primary goal of this project has been to evaluate and compare the effect of the intrinsic differences between cobalt (Co) and iron (Fe) catalysts for Fischer-Tropsch (FT) synthesis using coal-derived syngas. Crude oil, especially heavy, high-sulfur crude, is no longer the appropriate source for the additional, or marginal, amounts of middle-distillate fuels needed to meet growing US and world demand for diesel and jet fuels. Only about 1/3 of the marginal crude oil barrel can be made into diesel and jet fuels. The remaining 2/3 contributes further to global surpluses of by-products. FT can produce these needed marginal, low-sulfur middle-distillate fuels more efficiently, with less environmental impact, and from abundant US domestic resources. Cobalt FT catalyst is more efficient, and less expensive overall, than iron FT catalyst. Mechanisms of cobalt FT catalyst functioning, and poisoning, have been elucidated. Each of these primary findings is amplified by several secondary findings, and these are presented, and verified in detail. The most effective step the United States can take to begin building toward improved long-term national energy security, and to reduce dependence, over time, on imported crude oil from unfriendly and increasingly unstable areas of the world, is to begin producing additional, or marginal amounts of, middle-distillate-type fuels, such as ultralow sulfur diesel (ULSD) and jet fuel (not gasoline) from US domestic resources other than petroleum. FT synthesis of these middle distillate fuels offers the advantage of being able to use abundant and affordable US coal and biomass as the primary feedstocks. Use of the cobalt FT catalyst system has been shown conclusively to be more effective and less expensive than the use of iron FT catalyst with syngas derived from coal, or from coal and biomass combined. This finding is demonstrated in detail for the initial case of a relatively small FT plant of about 2000 barrels per day based upon coal

  12. Synthesis, characterization and gas sensing performance

    Indian Academy of Sciences (India)

    For the first time, this study reports the gas sensing performance of aluminosilicate azide cancrinite. The effect of annealing andoperating temperature on gas sensing characteristic of azide cancrinite thick film is investigated systematically for various gases at different operating temperatures. This sensor was observed to be ...

  13. Refinery Integration of By-Products from Coal-Derived Jet Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Caroline E. Burgess Clifford; Andre Boehman; Chunshan Song; Bruce Miller; Gareth Mitchell

    2007-03-17

    hydrodesulfurization. Equipment is now in place to begin fuel oil evaluations to assess the quality of coal based fuel oil. Combustion and characterization of the latest fuel oil (the high temperature fraction of RCO from the latest modification) indicates that the fraction is heavier than a No. 6 fuel oil. Combustion efficiency on our research boiler is {approx}63% for the heavy RCO fraction, lower than the combustion performance for previous co-coking fuel oils and No. 6 fuel oil. Emission testing indicates that the coal derived material has more trace metals related to coal than petroleum, as seen in previous runs. An additional coal has been procured and is being processed for the next series of delayed co-coking runs. The co-coking of the runs with the new coal have begun, with the coke yield similar to previous runs, but the gas yield is lower and the liquid yield is higher. Characterization of the products continues. Work continues on characterization of liquids and solids from co-coking of hydrotreated decant oils; liquid yields include more saturated and hydro- aromatics, while the coke quality varies depending on the conditions used. Pitch material is being generated from the heavy fraction of co-coking.

  14. Biological conversion of coal synthesis gas to methane

    Energy Technology Data Exchange (ETDEWEB)

    Barik, S; Corder, R E; Clausen, E C; Gaddy, J L

    1987-09-01

    High temperatures and pressures are required, and therefore, high costs incurred during catalytic upgrading of coal synthesis gas to methane. Thus, the feasibility of biological reactions in converting synthesis gas to methane has been demonstrated in mixed and pure cultures. Complete conversion has been achieved in 2 hours with a mixed culture, and 45 minutes to 1.5 hours in pure cultures of P. productus and Methanothrix sp.. Typical sulfur levels involved during the process are found not to inhibit the bacteria and so sulfur does not have to be removed prior to biomethanation. Preliminary economic analyses indicate that coal gas may be biologically methanated for 50-60 cents/million Btu. Further studies with pure culture bacteria and increased pressure are expected to enhance biomethanation economics.

  15. Synthesis, characterization and gas sensing property of ...

    Indian Academy of Sciences (India)

    Unknown

    et al 2000), drug delivery system (Panda et al 2001) and fuel cells (Gross et al 1998a; Verges et al 2000). It has promising application as a chemical gas sensor (Nagai et al .... apatite biomaterial ceramic was compacted into a pellet of 1⋅0 cm diameter having 0⋅15 cm thickness using poly- vinyl alcohol as binder material.

  16. NOVEL REACTOR FOR THE PRODUCTION OF SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Vasilis Papavassiliou; Leo Bonnell; Dion Vlachos

    2004-12-01

    Praxair investigated an advanced technology for producing synthesis gas from natural gas and oxygen This production process combined the use of a short-reaction time catalyst with Praxair's gas mixing technology to provide a novel reactor system. The program achieved all of the milestones contained in the development plan for Phase I. We were able to develop a reactor configuration that was able to operate at high pressures (up to 19atm). This new reactor technology was used as the basis for a new process for the conversion of natural gas to liquid products (Gas to Liquids or GTL). Economic analysis indicated that the new process could provide a 8-10% cost advantage over conventional technology. The economic prediction although favorable was not encouraging enough for a high risk program like this. Praxair decided to terminate development.

  17. Technologies for direct production of flexible H2/CO synthesis gas

    International Nuclear Information System (INIS)

    Song Xueping; Guo Zhancheng

    2006-01-01

    The use of synthesis gas offers the opportunity to furnish a broad range of environmentally clean fuels and high value chemicals. However, synthesis gas manufacturing systems based on natural gas are capital intensive, and hence, there is great interest in technologies for cost effective synthesis gas production. Direct production of synthesis gas with flexible H 2 /CO ratio, which is in agreement with the stoichiometric ratios required by major synthesis gas based petrochemicals, can decrease the capital investment as well as the operating cost. Although CO 2 reforming and catalytic partial oxidation can directly produce desirable H 2 /CO synthesis gas, they are complicated and continued studies are necessary. In fact, direct production of flexible H 2 /CO synthesis gas can be obtained by optimizing the process schemes based on steam reforming and autothermal reforming as well as partial oxidation. This paper reviews the state of the art of the technologies

  18. Synthesis of Zeolite Materials for Noble Gas Separation

    International Nuclear Information System (INIS)

    Achey, R.; Rivera, O.; Wellons, M.; Hunter, D.

    2017-01-01

    Microporous zeolite adsorbent materials are widely used as a medium for separating gases. Adsorbent gas separation systems can run at ambient temperature and require minimal pressure to flow the input gas stream across the adsorbent bed. This allows for low energy consumption relative to other types of separation systems. Specific zeolites also have a high capacity and selectivity for the gases of interest, leading to compact and efficient separation systems. These characteristics are particularly advantageous for the application of signatures detection for non-proliferation, which often requires portable systems with low power draw. Savannah River National Laboratory currently is the leader in using zeolites for noble gas sampling for non-proliferation detection platforms. However, there is a constant customer need for improved sampling capabilities. Development of improved zeolite materials will lead to improved sampling technology. Microwave-assisted and conventional hydrothermal synthesis have been used to make a variety of zeolites tailored for noble gas separation. Materials characterization data collected in this project has been used to help guide the synthesis of improved zeolite materials. Candidate materials have been down-selected based on highest available surface area, maximum overall capacity for gas adsorption and highest selectivity. The creation of improved adsorbent materials initiated in this project will lead to development of more compact, efficient and effective noble gas collectors and concentrators. The work performed in this project will be used as a foundation for funding proposals for further material development as well as possible industrial applications.

  19. Synthesis of Zeolite Materials for Noble Gas Separation

    Energy Technology Data Exchange (ETDEWEB)

    Achey, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Rivera, O. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Wellons, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hunter, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-10-02

    Microporous zeolite adsorbent materials are widely used as a medium for separating gases. Adsorbent gas separation systems can run at ambient temperature and require minimal pressure to flow the input gas stream across the adsorbent bed. This allows for low energy consumption relative to other types of separation systems. Specific zeolites also have a high capacity and selectivity for the gases of interest, leading to compact and efficient separation systems. These characteristics are particularly advantageous for the application of signatures detection for non-proliferation, which often requires portable systems with low power draw. Savannah River National Laboratory currently is the leader in using zeolites for noble gas sampling for non-proliferation detection platforms. However, there is a constant customer need for improved sampling capabilities. Development of improved zeolite materials will lead to improved sampling technology. Microwave-assisted and conventional hydrothermal synthesis have been used to make a variety of zeolites tailored for noble gas separation. Materials characterization data collected in this project has been used to help guide the synthesis of improved zeolite materials. Candidate materials have been down-selected based on highest available surface area, maximum overall capacity for gas adsorption and highest selectivity. The creation of improved adsorbent materials initiated in this project will lead to development of more compact, efficient and effective noble gas collectors and concentrators. The work performed in this project will be used as a foundation for funding proposals for further material development as well as possible industrial applications.

  20. Synthesis gas production from various biomass feedstocks

    Directory of Open Access Journals (Sweden)

    Juan A. Conesa

    2013-10-01

    Full Text Available The decomposition of five different biomass samples was studied in a horizontal laboratory reactor. The samples consisted of esparto grass, straw, Posidonea Oceanic seaweed, waste from urban and agricultural pruning and waste from forest pruning. Both pyrolysis in inert atmosphere and combustion in the presence of oxygen were studied. Different heating rates were used by varying the input speed. Major gas compounds were analyzed. The experimental results show that the amount of CO formed is lower in less dense species. It is also found that there is an increase of hydrocarbons formed at increasing feeding rates, in particular methane, while there is a decrease in the production of hydrogen.

  1. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Kwang-Bok Yi; Anirban Mukherjee; Elizabeth J. Podlaha; Douglas P. Harrison

    2004-03-01

    Mixed metal oxides containing ceria and zirconia have been studied as high temperature desulfurization sorbents with the objective of achieving the DOE Vision 21 target of 1 ppmv or less H{sub 2}S in the product gas. The research was justified by recent results in this laboratory that showed that reduced CeO{sub 2}, designated CeOn (1.5 < n < 2.0), is capable of achieving the 1 ppmv target in highly reducing gas atmospheres. The addition of ZrO{sub 2} has improved the performance of oxidation catalysts and three-way automotive catalysts containing CeO{sub 2}, and was postulated to have similar beneficial effects on CeO{sub 2} desulfurization sorbents. An electrochemical method for synthesizing CeO{sub 2}-ZrO{sub 2} mixtures was developed and the products were characterized by XRD and TEM during year 01. Nanocrystalline particles having a diameter of about 5 nm and containing from approximately 10 mol% to 80 mol% ZrO{sub 2} were prepared. XRD analysis showed the product to be a solid solution at low ZrO{sub 2} contents with a separate ZrO{sub 2} phase emerging at higher ZrO{sub 2} levels. Unfortunately, the quantity of CeO{sub 2}-ZrO{sub 2} that could be prepared electrochemically was too small to permit desulfurization testing. Also during year 01 a laboratory-scale fixed-bed reactor was constructed for desulfurization testing. All components of the reactor and analytical systems that were exposed to low concentrations of H{sub 2}S were constructed of quartz, Teflon, or silcosteel. Reactor product gas composition as a function of time was determined using a Varian 3800 gas chromatograph equipped with a pulsed flame photometric detector (PFPD) for measuring low H{sub 2}S concentrations from approximately 0.1 to 10 ppmv, and a thermal conductivity detector (TCD) for higher concentrations of H{sub 2}S. Larger quantities of CeO{sub 2}-ZrO{sub 2} mixtures from other sources, including mixtures prepared in this laboratory using a coprecipitation procedure, were obtained

  2. ISOBUTANOL-METHANOL MIXTURES FROM SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Enrique Iglesia

    1998-09-01

    Isobutanol is potential as a fuel additive or precursor to methyl tert-butyl ether (MTBE). Alkali-promoted Cu/ZnO/Al{sub 2}O{sub 3} and Cu/MgO/CeO{sub 2} materials have been found to catalyze the formation of isobutanol from CO and H{sub 2} at temperatures (573-623 K) that allow their use in slurry reactors. Our studies focus on the mechanism and structural requirements for selective isobutanol synthesis on these types of catalysts. Alkali promoted Cu/MgO/CeO{sub 2}, Cu/MgO/ZnO, and CuZnAlO{sub x} materials and their individual components Cu/MgO, MgO/CeO{sub 2}, MgO and CeO{sub 2} have been prepared for the use in kinetic studies of alcohol coupling reactions, in identification of reaction intermediates, and in isobutanol synthesis at high pressures. These samples were prepared by coprecipitation of mixed nitrate solutions with an aqueous solution of KOH (2M) and K{sub 2}CO{sub 3} (1M) at 338 K at a constant pH of 9, except for Cs-Cu/ZnO/Al{sub 2}O{sub 3} at a pH of 7, in a well-stirred thermostated container. The precipitate was filtered, washed thoroughly with dioinized water at 303 K in order to remove residual K ions, and dried at 353 K overnight. Dried samples were calcined at 723 K, except for Cs-Cu/ZnO/Al{sub 2}O{sub 3} at 623 K, for 4 h in order to form the corresponding mixed oxides. Alkali addition (K or Cs) was performed by incipient wetness using K{sub 2}CO{sub 3} (0.25 M) and CH{sub 3}COOCs (0.25 M) aqueous solutions. The crystallinity and phase structures of resulting materials were analyzed by powered X-ray diffraction.

  3. Oxygenated base chemicals from synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Roeper, M.

    1984-11-01

    Methyl formate, a syngas based intermediate, is already today produced on large scale by base catalyzed methanol carbonylation. An alternative synthesis, based on methanol dehydrogenation, seems to be ready for commercialization, whereas other routes including direct carbon monoxide hydrogenation, formaldehyde disproportionation or methanol oxydehydrogenation are less advanced. Besides being used as a solvent or an insect control agent, methyl formate serves as a feedstock for e.g. formic acid, formamide, N,N-dimethylformamide, and N-formyl morpholine. Newer formic acid processes are based on direct hydrolysis of methyl formate, and appear to replace the traditional indirect formamide based route. Future use of methyl formate could include the production of pure carbon monoxide, methanol, dimethyl carbonate, diphosgene, ethylene glycol via methyl glycolate, acetic acid, and methyl propionate. All these processes either avoid the use of high purity carbon monoxide or proceed under milder conditions than conventional routes. They could gain interest, if syngas and methanol become available at a large scale as competitive feedstocks for the chemical industry.

  4. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Anirban Mukherjee; Kwang-Bok Yi; Elizabeth J. Podlaha; Douglas P. Harrison

    2001-11-01

    Mixed metal oxides containing CeO{sub 2} and ZrO{sub 2} are being studied as high temperature desulfurization sorbents capable of achieving the DOE Vision 21 target of 1 ppmv of less H{sub 2}S. The research is justified by recent results in this laboratory that showed that reduced CeO{sub 2}, designated CeO{sub n} (1.5 < n < 2.0), is capable of achieving the 1 ppmv target in highly reducing gas atmospheres. The addition of ZrO{sub 2} has improved the performance of oxidation catalysts and three-way automotive catalysts containing CeO{sub 2}, and should have similar beneficial effects on CeO{sub 2} desulfurization sorbents. An electrochemical method for synthesizing CeO{sub 2}-ZrO{sub 2} has been developed and the products have been characterized by XRD and TEM during year 01. Nanocrystalline particles having a diameter of about 5 nm and containing from approximately 10 mol% to 80 mol% ZrO{sub 2} have been prepared. XRD showed the product to be a solid solution at low ZrO{sub 2} contents with a separate ZrO{sub 2} phase emerging at higher ZrO{sub 2} levels. Phase separation did not occur when the solid solutions were heat treated at 700 C. A flow reactor system constructed of quartz and teflon has been constructed, and a gas chromatograph equipped with a pulsed flame photometric detector (PFPD) suitable for measuring sub-ppmv levels of H{sub 2}S has been purchased with LSU matching funds. Preliminary desulfurization tests using commercial CeO{sub 2} and CeO{sub 2}-ZrO{sub 2} in highly reducing gas compositions has confirmed that CeO{sub 2}-ZrO{sub 2} is more effective than CeO{sub 2} in removing H{sub 2}S. At 700 C the product H{sub 2}S concentration using CeO{sub 2}-ZrO{sub 2} sorbent was near the 0.1 ppmv PFPD detection limit during the prebreakthrough period.

  5. Proceedings of the DGMK-conference 'Synthesis gas chemistry'. Authors' manuscripts

    Energy Technology Data Exchange (ETDEWEB)

    Hoenicke, D.; Kohlpaintner, C.; Luecke, B.; Reschetilowski, W. [eds.

    2000-07-01

    The main topics of the DGMK-Conference ''Synthesis Gas Chemistry'' were: production of synthesis gas from several educts, new catalysts, Fischer-Tropsch synthesis, hydroformylation, steam reforming and carbonylation.

  6. Synthesis gas production via hybrid steam reforming of natural gas and bio-liquids

    NARCIS (Netherlands)

    Balegedde Ramachandran, P.

    2013-01-01

    This thesis deals with (catalytic) steam reforming of bio-liquids for the production of synthesis gas. Glycerol, both crude from the biodiesel manufacturing and refined, and pyrolysis oil are tested as bio-based feedstocks. Liquid bio-based feeds could be preferred over inhomogeneous fibrous solid

  7. Thermodynamic models to predict gas-liquid solubilities in the methanol synthesis, the methanol-higher alcohol synthesis, and the Fischer-Tropsch synthesis via gas-slurry processes

    NARCIS (Netherlands)

    Breman, B.B; Beenackers, A.A C M

    1996-01-01

    Various thermodynamic models were tested concerning their applicability to predict gas-liquid solubilities, relevant for synthesis gas conversion to methanol, higher alcohols, and hydrocarbons via gas-slurry processes. Without any parameter optimization the group contribution equation of state

  8. Chromatographic methods and techniques used in studies of coals, their progenitors and coal-derived materials

    Energy Technology Data Exchange (ETDEWEB)

    Zubkova, Valentina [Jan Kochanowski University of Humanities and Sciences, Institute of Chemistry, Kielce (Poland)

    2011-03-15

    The use of chromatography in studies of coals, their progenitors and coal-related products was reviewed. The specificity of the coal structure was discussed. The use of extraction in preparing study samples was discussed paying special attention to the occurrence of undesirable phenomena such as aggregation of coal derivate molecules, resulting from the formation of their dimers and trimers, and degradation of polar solvents at temperatures above 350 C. The following ways of fractionating samples of coal materials were considered: thermal, solvent, column with the use of preparative size exclusive chromatography and preparative thin layer chromatography as well as membrane separation. The use of chromatography coupled with experimental techniques such as mass spectrometry, infrared spectroscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and pyrolysis was analysed. (orig.)

  9. Catalytic Production of Ethanol from Biomass-Derived Synthesis Gas

    Energy Technology Data Exchange (ETDEWEB)

    Trewyn, Brian G. [Colorado School of Mines, Golden, CO (United States); Smith, Ryan G. [Iowa State Univ., Ames, IA (United States)

    2016-06-01

    Heterogeneous catalysts have been developed for the conversion of biomass-derived synthetic gas (syngas) to ethanol. The objectives of this project were to develop a clean synthesis gas from biomass and develop robust catalysts with high selectivity and lifetime for C2 oxygenate production from biomass-derived syngas and surrogate syngas. During the timeframe for this project, we have made research progress on the four tasks: (1) Produce clean bio-oil generated from biomass, such as corn stover or switchgrass, by using fast pyrolysis system, (2) Produce clean, high pressure synthetic gas (syngas: carbon monoxide, CO, and hydrogen, H2) from bio-oil generated from biomass by gasification, (3) Develop and characterize mesoporous mixed oxide-supported metal catalysts for the selective production of ethanol and other alcohols, such as butanol, from synthesis gas, and (4) Design and build a laboratory scale synthesis gas to ethanol reactor system evaluation of the process. In this final report, detailed explanations of the research challenges associated with this project are given. Progress of the syngas production from various biomass feedstocks and catalyst synthesis for upgrading the syngas to C2-oxygenates is included. Reaction properties of the catalyst systems under different reaction conditions and different reactor set-ups are also presented and discussed. Specifically, the development and application of mesoporous silica and mesoporous carbon supports with rhodium nanoparticle catalysts and rhodium nanoparticle with manganese catalysts are described along with the significant material characterizations we completed. In addition to the synthesis and characterization, we described the activity and selectivity of catalysts in our micro-tubular reactor (small scale) and fixed bed reactor (larger scale). After years of hard work, we are proud of the work done on this project, and do believe that this work will provide a solid

  10. Intrinsic and extrinsic defects in a family of coal-derived graphene quantum dots

    Science.gov (United States)

    Singamaneni, Srinivasa Rao; van Tol, Johan; Ye, Ruquan; Tour, James M.

    2015-11-01

    In this letter, we report on the high frequency (239.2 and 336 GHz) electron spin resonance (ESR) studies performed on graphene quantum dots (GQDs), prepared through a wet chemistry route from three types of coal: (a) bituminous, (b) anthracite, and (c) coke; and from non-coal derived GQDs. The microwave frequency-, power-, and temperature-dependent ESR spectra coupled with computer-aided simulations reveal four distinct magnetic defect centers. In bituminous- and anthracite-derived GQDs, we have identified two of them as intrinsic carbon-centered magnetic defect centers (a broad signal of peak to peak width = 697 (10-4 T), g = 2.0023; and a narrow signal of peak to peak width = 60 (10-4 T), g = 2.003). The third defect center is Mn2+ (6S5/2, 3d5) (signal width = 61 (10-4 T), g = 2.0023, Aiso = 93(10-4 T)), and the fourth defect is identified as Cu2+ (2D5/2, 3d9) (g⊥ = 2.048 and g‖ = 2.279), previously undetected. Coke-derived and non-coal derived GQDs show Mn2+ and two-carbon related signals, and no Cu2+ signal. The extrinsic impurities most likely originate from the starting coal. Furthermore, Raman, photoluminescence, and ESR measurements detected no noticeable changes in the properties of the bituminous GQDs after one year. This study highlights the importance of employing high frequency ESR spectroscopy in identifying the (magnetic) defects, which are roadblocks for spin relaxation times of graphene-based materials. These defects would not have been possible to probe by other spin transport measurements.

  11. France independent on gas by 2050. A 100 pc renewable gas mix by 2050? Study synthesis

    International Nuclear Information System (INIS)

    Chapelon, Guillain; Rabetsimamanga, Ony; Bosso, Valerie; Frederic, Sylvain; Legrand, Stephanie; Leboul-Proust, Catherine; Monin, William; Singly, Bertrand de; Combet, Emmanuel; Marchal, David; Meunier, Laurent; Varet, Anne; Vincent, Isabelle; Antoine, Loic; Bardinal, Marc; Bastide, Guillaume; Bodineau, Luc; Canal, David; El Khamlichi, Aicha; Gagnepain, Bruno; Mainsant, Arnaud; Parrouffe, Jean-Michel; Pouet, Jean-Christophe; Theobald, Olivier; Vidalenc, Eric; Thomas, Alban; Madiec, Philippe; Meradi, Sabra; Boure, Quentin; Cherrey, Marc; Coupe, Florian; Couturier, Christian; Metivier, Simon; Chiche, Alice

    2018-01-01

    This document proposes a synthesis of a study which aimed at determining what could be an available renewable or recovery gas resource by 2050 in metropolitan France, whether it would be sufficient to face gas demand every day and at any point of the network, which network or production sector evolutions would be needed, which are the available constraints and leeway, and which would be the impact on the average cost of supplied gas. Potential renewable resources come from methanization, pyro-gasification, and power-to-gas. The production mix assessment is based on an ADEME scenario for 2035-2050. Four scenarios have been defined to assess the different hypotheses, notably resources: a 100 per cent renewable and recovery energies, a 100 per cent renewable and recovery energies with a high pyro-gasification, a 100 per cent renewable and recovery energies with a biomass restrained to gas usages, and a 75 per cent renewable and recovery. Results are presented in terms of theoretical potential, gas demand meeting, cost, and avoided emissions. Lessons learned concern the possibility of a 100 per cent renewable gas system with necessary evolutions, and a complementarity between the gas and electric networks. Limitations and perspectives are discussed

  12. Intrinsic and extrinsic defects in a family of coal-derived graphene quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Singamaneni, Srinivasa Rao, E-mail: ssingam@ncsu.edu, E-mail: tour@rice.edu [Materials Science Division, Army Research Office, Research Triangle Park, North Carolina 27709 (United States); Department of Material Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Tol, Johan van [National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Drive, Tallahassee, Florida 32310 (United States); Ye, Ruquan [Department of Chemistry, Rice University, MS-222, 6100 Main Street, Houston, Texas 77005 (United States); Tour, James M., E-mail: ssingam@ncsu.edu, E-mail: tour@rice.edu [Department of Chemistry, Rice University, MS-222, 6100 Main Street, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, MS-222, 6100 Main Street, Houston, Texas 77005 (United States); Smalley Institute for Nanoscale Science and Technology, Rice University, MS-222, 6100 Main Street, Houston, Texas 77005 (United States)

    2015-11-23

    In this letter, we report on the high frequency (239.2 and 336 GHz) electron spin resonance (ESR) studies performed on graphene quantum dots (GQDs), prepared through a wet chemistry route from three types of coal: (a) bituminous, (b) anthracite, and (c) coke; and from non-coal derived GQDs. The microwave frequency-, power-, and temperature-dependent ESR spectra coupled with computer-aided simulations reveal four distinct magnetic defect centers. In bituminous- and anthracite-derived GQDs, we have identified two of them as intrinsic carbon-centered magnetic defect centers (a broad signal of peak to peak width = 697 (10{sup −4} T), g = 2.0023; and a narrow signal of peak to peak width = 60 (10{sup −4} T), g = 2.003). The third defect center is Mn{sup 2+} ({sup 6}S{sub 5/2}, 3d{sup 5}) (signal width = 61 (10{sup −4} T), g = 2.0023, A{sub iso} = 93(10{sup −4} T)), and the fourth defect is identified as Cu{sup 2+} ({sup 2}D{sub 5/2}, 3d{sup 9}) (g{sub ⊥} = 2.048 and g{sub ‖} = 2.279), previously undetected. Coke-derived and non-coal derived GQDs show Mn{sup 2+} and two-carbon related signals, and no Cu{sup 2+} signal. The extrinsic impurities most likely originate from the starting coal. Furthermore, Raman, photoluminescence, and ESR measurements detected no noticeable changes in the properties of the bituminous GQDs after one year. This study highlights the importance of employing high frequency ESR spectroscopy in identifying the (magnetic) defects, which are roadblocks for spin relaxation times of graphene-based materials. These defects would not have been possible to probe by other spin transport measurements.

  13. Coal pyrolysis under synthesis gas, hydrogen and nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Ariunaa, A.; Li Bao-Qing; Li Wen; Purevsuren, B. (and others) [Chinese Academy of Sciences, Taiyuan (China)

    2007-02-15

    Chinese Xundian, Mongolian Shiveeovoo lignites and Khoot oil shale are pyrolyzed under synthesis gas (SG) at temperature range from 400 to 800{sup o}C for lignite and from 300 to 600{sup o}C for oil shale with heating rate of 10{sup o}C/min in a fixed bed reactor. The results were compared with those obtained by pyrolysis under hydrogen and nitrogen. The results showed that unlike pyrolysis at high pressure, there are only slight different in the yields of char and tar among pyrolyses under various gases at room pressure for lignite, while higher liquid yield with lower yields of char and gas was obtained in pyrolysis of oil shale under SG and H{sub 2} than under N{sub 2}. It is found that the pyrite S can be easily removed to partially convert to organic S under various gaseous atmosphere and the total sulfur removal for oil shale is much less than lignite, which might be related to its high ash content. The higher total sulfur removal and less organic S content in the presence of SG in comparison with those under N{sub 2} and even under H{sub 2} in pyrolysis of Xundian lignite might result from the action of CO in SG. However, CO does not show its function in pyrolysis of Khoot oil shale, which might also be related to the high ash content. The results reported show the possibility of using synthesis gas instead of pure hydrogen as the reactive gas for coal hydropyrolysis. 11 refs., 4 figs., 6 tabs.

  14. Chemistry and structure of coal derived asphaltenes and preasphaltenes. Quarterly progress report, April-June 1980

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T. F.

    1980-01-01

    It is the objective of this project to isolate the asphaltene and preasphaltene fractions from coal liquids from a number of liquefaction processes. These processes consist of in general: catalytic hydrogenation, staged pyrolysis and solvent refining. These asphaltene fractions may be further separated by both gradient elution through column chromatography, and molecular size distribution through gel permeation chromatography. Those coal-derived asphaltene and preasphaltene fractions will be investigated by various chemical and physical methods for characterization of their structures. After the parameters are obtained, these parameters will be correlated with the refining and conversion variables which control a given type of liquefaction process. The effects of asphaltene in catalysis, ash or metal removal, desulfurization and denitrification will also be correlated. It is anticipated that understanding the role of asphaltenes in liquefaction processes will enable engineers to both improve existing processes, and to make recommendations for operational changes in planned liquefaction units in the United States. The objective of Phase 1 was to complete the isolation and separation of coal liquid fractions and to initiate their characterization. The objective of Phase 2 is to continue the characterization of coal asphaltenes and other coal liquid fractions by use of physical and instrumental methods. The structural parameters obtained will be used to postulate hypothetical average structures for coal liquid fractions. The objective of Phase 3 is to concentrate on the characterization of the preasphaltene (benzene insoluble fraction) of coal liquid fraction by the available physical and chemical methods to obtain a number of structural parameters.

  15. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; R. Michael Bergen; Stephen P. Carpenter; Dady Dadyburjor; Manoj Katakdaunde; Liviu Magean; Alfred H. Stiller; W. Morgan Summers; John W. Zondlo

    2006-05-12

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, coking and composite fabrication continued using coal-derived samples. These samples were tested in direct carbon fuel cells. Methodology was refined for determining the aromatic character of hydro treated liquid, based on Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR). Tests at GrafTech International showed that binder pitches produced using the WVU solvent extraction protocol can result in acceptable graphite electrodes for use in arc furnaces. These tests were made at the pilot scale.

  16. Synthesis gas solubility in Fischer-Tropsch slurry: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Chao, K.C.; Lin, H.M.

    1988-01-01

    The objective is to investigate the phase equilibrium behavior of synthesis gases and products in a Fischer-Tropsch slurry reactor. A semi-flow apparatus has been designed and constructed for this purpose. Measurements have been made for hydrogen, cabon monoxide, methane, ethane, ethylene, and carbon dioxide in a heavy n-paraffin at temperatures from 100 to 300)degree)C and pressures 10 to 50 atm. Three n-paraffin waxes: n-eicosane (n-C/sub 20/), n-octacosane )n-C/sub 28/), and n-hexatriacontane (n-C/sub 36/), were studied to model the industrial wax. Solubility of synthesis gas mixtures of H/sub 2/ and CO in n-C/sub 28/ was also determined at two temperatures (200 and 300)degree)C) for each of three gas compositions (40.01, 50.01, and 66.64 mol%) of hydrogen). Measurements were extended to investigate the gas solubility in two industrial Fischer-Tropsch waxes: Mobilwax and SASOL wax. Observed solubility increases in the order: H/sub 2/, CO, CH/sub 4/, CO/sub 2/, C/sub 2/H/sub 4/, C/sub 2/H/sub 6/, at a given temperature pressure, and in the same solvent. Solubility increases with increasing pressure for all the gases. Lighter gases H/sub 2/ and CO show increased solubility with increasing temperature, while the heavier gases CO/sub 2/, ethane, and ethylene show decreased solubility with increasing temperature. The solubility of methane, the intermediate gas, changes little with temperature, and shows a shallow minimum at about 200)degrees)C or somewhat above. Henry's constant and partial molal volume of the gas solute at infinite dilution are determinedfrom the gas solubility data. A correlation is developed from the experimental data in the form on an equation of state. A computer program has been prepared to implement the correlation. 19 refs., 66 figs., 39 tabs.

  17. Sustainable synthesis gas from biomass. A bridge to a sustainable supply of energy and resources

    International Nuclear Information System (INIS)

    Den Uil, H.; Van Ree, R.; Van der Drift, A.; Boerrigter, H.

    2004-04-01

    Synthesis gas is currently primarily used in the (petro)chemical industry and for the production of liquid fuels. Smaller amounts are being used for electricity and synthetic natural gas (=SNG) production. Finite fossil resources, the dependence on political instable regimes and the Kyoto-protocol are drivers for the attention for renewable synthesis gas. In this report the market for, production of, use of and economy of renewable synthesis gas are analysed. Current synthesis gas use is limited to about 3% of the Dutch primary energy consumption; worldwide this is about 2%. Driven by the targets for renewable energy and the wide range of possible uses, the market for renewable synthesis gas has a large potential. When using synthesis gas for the production of SNG, electricity, liquid fuels and chemicals, the Dutch market for renewable synthesis gas can be 150 PJ in 2010, doubling about every decade to 1500 PJ in 2040. SNG and electricity, together about 80%. To reach these market volumes, import of biomass will be required due to the limited availability of local biomass resources in the Netherlands. The specifications for synthesis gas are dependent on the application. For (petro)chemical use and the production of liquid fuels high H2 and CO concentrations are required, for SNG and electricity production high CH4 concentrations are preferred. Due to the different specifications the names synthesis gas and product gas are used in this study. The name synthesis gas is claimed for a large number of gasification processes under development. But only for a number of processes this claim is justified. The gasification temperature determines the type of gas produced. At high temperatures, above 1300C, synthesis gas is produced, at low temperatures, 700-1000C, so-called product gas is being produced. Entrained-flow gasification is the only possibility for large-scale synthesis gas production in one step. For this process the particle size of the feed has to be small

  18. Novel catalysts for upgrading coal-derived liquids. Final technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, L.T.; Savage, P.E.; Briggs, D.E.

    1995-03-31

    Research described in this report was aimed at synthesizing and evaluating supported Mo oxynitrides and oxycarbides for the selective removal of nitrogen, sulfur and oxygen from model and authentic coal-derived liquids. The Al{sub 2}O{sub 3}-supported oxynitrides and oxycarbides were synthesized via the temperature programmed reaction of supported molybdenum oxides or hydrogen bronzes with NH{sub 3} or an equimolar mixture of CH{sub 4} and H{sub 2}. Phase constituents and composition were determined by X-ray diffraction, CHN analysis, and neutron activation analysis. Oxygen chemisorption was used to probe the surface structure of the catalysts. The reaction rate data was collected using specially designed micro-batch reactors. The Al{sub 2}O{sub 3}-supported Mo oxynitrides and oxycarbides were competitively active for quinoline hydrodenitrogenation (HDN), benzothiophene hydrodesulfurization (HDS) and benzofuran hydrodeoxygenation (HDO). In fact, the HDN and HDO specific reaction rates for several of the oxynitrides and oxycarbides were higher than those of a commercial Ni-Mo/Al{sub 2}O{sub 3} hydrotreatment catalyst. Furthermore, the product distributions indicated that the oxynitrides and oxycarbides were more hydrogen efficient than the sulfide catalysts. For HDN and HDS the catalytic activity was a strong inverse function of the Mo loading. In contrast, the benzofuran hydrodeoxygenation (HDO) activities did not appear to be affected by the Mo loading but were affected by the heating rate employed during nitridation or carburization. This observation suggested that HDN and HDS occurred on the same active sites while HDO was catalyzed by a different type of site.

  19. Gas-phase synthesis of magnetic metal/polymer nanocomposites

    Science.gov (United States)

    Starsich, Fabian H. L.; Hirt, Ann M.; Stark, Wendelin J.; Grass, Robert N.

    2014-12-01

    Highly magnetic metal Co nanoparticles were produced via reducing flame spray pyrolysis, and directly coated with an epoxy polymer in flight. The polymer content in the samples varied between 14 and 56 wt% of nominal content. A homogenous dispersion of Co nanoparticles in the resulting nanocomposites was visualized by electron microscopy. The size and crystallinity of the metallic fillers was not affected by the polymer, as shown by XRD and magnetic hysteresis measurements. The good control of the polymer content in the product nanocomposite was shown by elemental analysis. Further, the successful polymerization in the gas phase was demonstrated by electron microscopy and size measurements. The presented effective, dry and scalable one-step synthesis method for highly magnetic metal nanoparticle/polymer composites presented here may drastically decrease production costs and increase industrial yields.

  20. Electron-beam synthesis of fuel in the gas phase

    International Nuclear Information System (INIS)

    Ponomarev, A.V.; Holodkova, E.M.; Ershov, B.G.

    2011-01-01

    Complete text of publication follows. Tendencies of world development focus attention on a vegetative biomass as on the major raw resource for future chemistry and a fuel industry. The significant potential for perfection of biomass conversion processes is concentrated in the field of radiation-chemical methods. Both the mode of post-radiation distillation and mode of electron-beam distillation of biomass have been investigated as well as the mode of gas-phase synthesis of liquid engine fuel from of biomass distillation products. Synergistic action of radiation and temperature has been analyzed at use of the accelerated electron beams allowing to combine radiolysis with effective radiation heating of a material without use of additional heaters. At dose rate above 1 kGy/s the electron-beam irradiation results in intensive decomposition of a biomass and evaporation of formed fragments with obtaining of a liquid condensate (∼ 60 wt%), CO 2 and Co gases (13-18 wt%) and charcoal in the residue. Biomass distillation at radiation heating allows to increase almost three times an organic liquid yield in comparison with pyrolysis. The majority of liquid products from cellulose is represented by the furan derivatives considered among the very perspective components for alternative engine fuels. Distilled-off gases and vapors are diluted with gaseous C 1 -C 5 alkanes and again are exposed to an irradiation to produce liquid fuel from a biomass. This transformation is based on a method of electron-beam circulation conversion of gaseous C 1 -C 5 alkanes (Ponomarev, A.V., Radiat. Phys. Chem., 78, 48, 2009) which consists in formation and removal of liquid products with high degree of carbon skeleton branching. The isomers ratio in a liquid may be controlled by means of change of an irradiation condition and initial gas composition. The irradiation of gaseous alkanes together with vaporous products of biomass destruction allows to synthesize the fuel enriched by conventional

  1. Some technical subjects on production of hydrocarbon fuel from synthetic gas

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Takashi

    1987-06-20

    Since fuel oil meeting the requirements of current petroleum products can be produced by SASOL F-T synthetic process, the manufacturing process of hydrocarbon fuel oil from the coal-derived synthesis gas, downstream processes are being successively investigated. Mobile M-gasoline, MTG, process which produces gasoline from the natural gas-derived synthesis gas through methanol went into commercial operation in New Zealand in 1986. Although the gasoline suffices the quality of commercial gasoline by both fixed bed and fluidized bed systems, the price and service life of catalyst and control of by-product durene must be improved. Any STG processes have not been completed yet and the yield and quality of gasoline are inferior to those of gasoline produced by the MTG process. Applying two-stage process, the STG process will be more economically effective.(21 refs, 4 figs, 10 tabs)

  2. Gas-phase synthesis of semiconductor nanocrystals and its applications

    Science.gov (United States)

    Mandal, Rajib

    Luminescent nanomaterials is a newly emerging field that provides challenges not only to fundamental research but also to innovative technology in several areas such as electronics, photonics, nanotechnology, display, lighting, biomedical engineering and environmental control. These nanomaterials come in various forms, shapes and comprises of semiconductors, metals, oxides, and inorganic and organic polymers. Most importantly, these luminescent nanomaterials can have different properties owing to their size as compared to their bulk counterparts. Here we describe the use of plasmas in synthesis, modification, and deposition of semiconductor nanomaterials for luminescence applications. Nanocrystalline silicon is widely known as an efficient and tunable optical emitter and is attracting great interest for applications in several areas. To date, however, luminescent silicon nanocrystals (NCs) have been used exclusively in traditional rigid devices. For the field to advance towards new and versatile applications for nanocrystal-based devices, there is a need to investigate whether these NCs can be used in flexible and stretchable devices. We show how the optical and structural/morphological properties of plasma-synthesized silicon nanocrystals (Si NCs) change when they are deposited on stretchable substrates made of polydimethylsiloxane (PDMS). Synthesis of these NCs was performed in a nonthermal, low-pressure gas phase plasma reactor. To our knowledge, this is the first demonstration of direct deposition of NCs onto stretchable substrates. Additionally, in order to prevent oxidation and enhance the luminescence properties, a silicon nitride shell was grown around Si NCs. We have demonstrated surface nitridation of Si NCs in a single step process using non?thermal plasma in several schemes including a novel dual-plasma synthesis/shell growth process. These coated NCs exhibit SiNx shells with composition depending on process parameters. While measurements including

  3. Oxidative regeneration of Ni-Mo-gamma-Al/sub 2/O/sub 3/ catalysts used for hydrotreatment of coal-derived oil

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Yuji; Furimsky, Edward; Sato, Toshio; Shimada, Hiromichi; Matsubayashi, Nobuyuki; Nishijima, Akio

    1986-10-23

    In order to easily find the oxidative reaction characteristics of carbonaceous materials and sulfur deposited on the catalysts used for hydrogenation, oxidative regeneration behavior as studied with a fixed bed reactor, and the surfaces of the spent catalysts were analyzed by XPS to find the changes in form of active metals and sulfur on the catalysts. Ni-Mo-gamma-Al/sub 2/O/sub 3/ catalysts were used for hydrotreatment of primary coal-derived oil from Morwell coal. The spent catalysts were extracted by THF, dried and crushed into 100-200 mesh powder. The relation between catalyst regeneration temperature and CO/sub 2/ or SO/sub 2/, the relation between generated gas compositions and temperature in regeneration, and the activation energy of carbon and sulfur in the catalysts for oxidative reaction were indicated with data. As a result, it was found that a part of the active metals turned to sulfates by hydrotreatment and the residual sulfur existed in form of sulfate. ( 6 figs, 2 tabs, 4 refs )

  4. Boron-containing catalysts for dry reforming of methane to synthesis gas

    KAUST Repository

    Takanabe, Kazuhiro; Basset, Jean-Marie; Park, Jung-Hyun; Samal, Akshaya Kumar; Alsabban, Bedour

    2018-01-01

    The present invention uses a cobalt catalyst for carbon dioxide reforming of lower alkanes to synthesis gas having a cobalt catalyst on an oxide support where the supported cobalt catalyst has been modified with a boron precursor. The boron

  5. The selective generation of acetic acid directly from synthesis gas

    International Nuclear Information System (INIS)

    Knifton, J.F.

    1986-01-01

    The authors conclude that each of the ruthenium, cobalt and iodide-containing catalyst components have very specific roles to play in the ''melt'' catalyzed conversion of synthesis gas to acetic acid. C 1 -Oxygenate formation is only observed in the presence of ruthenium carbonyls - [Ru(CO) 3 I 3 ] - is here the dominant species - and there is a direct relationship between liquid yield, ΣOAc - productivity and [Ru(CO) 3 I 3 ] - content. Controlled quantities of iodide ensure that initially formed MeOH is rapidly converted to the more reactive methyl iodide. Subsequent cobalt-catalyzed carbonylation to acetic acid may be preparatively attractive (>80% selectivity, good yields) relative to competing syntheses, where the [Co(CO) 4 ] - concentration is maximized that is, where the Co/Ru ratio is >1, the syngas feedstock is rich in CO, and the initial iodide/cobalt ratios are ca. unity. Formation of cobalt-iodide species appears to be a competing, inhibitory step in this catalysis

  6. Bendable Zeolite Membranes: Synthesis and Improved Gas Separation Performance.

    Science.gov (United States)

    Wang, Bo; Ho, W S Winston; Figueroa, Jose D; Dutta, Prabir K

    2015-06-23

    Separation and sequestration of CO2 emitted from fossil energy fueled electric generating units and industrial facilities will help in reducing anthropogenic CO2, thereby mitigating its adverse climate change effects. Membrane-based gas separation has the potential to meet the technical challenges of CO2 separation if high selectivity and permeance with low costs for large-scale manufacture are realized. Inorganic zeolite membranes in principle can have selectivity and permeance considerably higher than polymers. This paper presents a strategy for zeolite growth within the pores of a polymer support, with crystallization time of an hour. With a thin coating of 200-300 nm polydimethylsiloxane (PDMS) on the zeolite-polymer composite, transport data for CO2/N2 separation indicate separation factors of 35-45, with CO2 permeance between 1600 and 2200 GPU (1 GPU = 3.35 × 10(-10) mol/(m(2) s Pa)) using dry synthetic mixtures of CO2 and N2 at 25 °C. The synthesis process results in membranes that are highly reproducible toward transport measurements and exhibit long-term stability (3 days). Most importantly, these membranes because of the zeolite growth within the polymer support, as contrasted to conventional zeolite growth on top of a support, are mechanically flexible.

  7. Metabolic modeling of synthesis gas fermentation in bubble column reactors.

    Science.gov (United States)

    Chen, Jin; Gomez, Jose A; Höffner, Kai; Barton, Paul I; Henson, Michael A

    2015-01-01

    A promising route to renewable liquid fuels and chemicals is the fermentation of synthesis gas (syngas) streams to synthesize desired products such as ethanol and 2,3-butanediol. While commercial development of syngas fermentation technology is underway, an unmet need is the development of integrated metabolic and transport models for industrially relevant syngas bubble column reactors. We developed and evaluated a spatiotemporal metabolic model for bubble column reactors with the syngas fermenting bacterium Clostridium ljungdahlii as the microbial catalyst. Our modeling approach involved combining a genome-scale reconstruction of C. ljungdahlii metabolism with multiphase transport equations that govern convective and dispersive processes within the spatially varying column. The reactor model was spatially discretized to yield a large set of ordinary differential equations (ODEs) in time with embedded linear programs (LPs) and solved using the MATLAB based code DFBAlab. Simulations were performed to analyze the effects of important process and cellular parameters on key measures of reactor performance including ethanol titer, ethanol-to-acetate ratio, and CO and H2 conversions. Our computational study demonstrated that mathematical modeling provides a complementary tool to experimentation for understanding, predicting, and optimizing syngas fermentation reactors. These model predictions could guide future cellular and process engineering efforts aimed at alleviating bottlenecks to biochemical production in syngas bubble column reactors.

  8. Synthesis gas demonstration plant program, Phase I. Site confirmation report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    With few reservations, the Baskett, Kentucky site exhibits the necessary characteristics to suggest compatibility with the proposed Synthesis Gas Demonstration Plant Project. An evaluation of a broad range of technical disciplinary criteria in consideration of presently available information indicated generally favorable conditions or, at least, conditions which could be feasibly accommodated in project design. The proximity of the Baskett site to market areas and sources of raw materials as well as a variety of transportation facilities suggests an overall favorable impact on Project economic feasibility. Two aspects of environmental engineering, however, have been identified as areas where the completion or continuation of current studies are required before removing all conditions on site suitability. The first aspect involves the current contradictory status of existing land use and planning ordinances in the site area. Additional investigation of the legality of, and local attitudes toward, these present plans is warranted. Secondly, terrestrial and aquatic surveys of plant and animal life species in the site area must be completed on a seasonal basis to confirm the preliminary conclusion that no exclusionary conditions exist.

  9. Ion transport membrane reactor systems and methods for producing synthesis gas

    Science.gov (United States)

    Repasky, John Michael

    2015-05-12

    Embodiments of the present invention provide cost-effective systems and methods for producing a synthesis gas product using a steam reformer system and an ion transport membrane (ITM) reactor having multiple stages, without requiring inter-stage reactant injections. Embodiments of the present invention also provide techniques for compensating for membrane performance degradation and other changes in system operating conditions that negatively affect synthesis gas production.

  10. Integrated report on the toxicological mitigation of coal liquids by hydrotreatment and other processes. [Petroleum and coal-derived products

    Energy Technology Data Exchange (ETDEWEB)

    Guerin, M.R.; Griest, W.H.; Ho, C.H.; Smith, L.H.; Witschi, H.P.

    1986-06-01

    Research here on the toxicological properties of coal-derived liquids focuses on characterizing the refining process and refined products. Principle attention is given to the potential tumorigenicity of coal-derived fuels and to the identification of means to further reduce tumorigenicity should this be found necessary. Hydrotreatment is studied most extensively because it will be almost certainly required to produce commercial products and because it is likely to also greatly reduce tumorigenic activity relative to that of crude coal-liquid feedstocks. This report presents the results of a lifetime C3H mouse skin tumorigenicity assay of an H-Coal series of oils and considers the relationships between tumorigenicity, chemistry, and processing. Lifetime assay results are reported for an H-Coal syncrude mode light oil/heavy oil blend, a low severity hydrotreatment product, a high severity hydrotreatment product, a naphtha reformate, a heating oil, a petroleum-derived reformate, and a petroleum derived heating oil. Data are compared with those for an earlier study of an SRC-II blend and products of its hydrotreatment. Adequate data are presented to allow an independent qualitative assessment of the conclusions while statistical evaluation of the data is being completed. The report also documents the physical and chemical properties of the oils tested. 33 refs., 14 figs., 53 tabs.

  11. Research in Korea on Gas Phase Synthesis and Control of Nanoparticles

    International Nuclear Information System (INIS)

    Choi, Mansoo

    2001-01-01

    Research activity into the gas phase synthesis of nanoparticles has witnessed rapid growth on a worldwide basis, which is also reflected by Korean research efforts. Nanoparticle research is inherently a multi-disciplinary activity involving both science and engineering. In this paper, the recent studies undertaken in Korea on the gas phase synthesis and control of nanoparticles are reviewed. Studies on the synthesis of various kinds of nanoparticles are first discussed with a focus on the different types of reactors used. Recent experimental and theoretical studies and newly developed methods of measuring and modeling nanoparticle growth are also reviewed

  12. Gas-Phase Combustion Synthesis of Aluminum Nitride Powder

    Science.gov (United States)

    Axelbaum, R. L.; Lottes, C. R.; Huertas, J. I.; Rosen, L. J.

    1996-01-01

    Due to its combined properties of high electrical resistivity and high thermal conductivity aluminum nitride (AlN) is a highly desirable material for electronics applications. Methods are being sought for synthesis of unagglomerated, nanometer-sized powders of this material, prepared in such a way that they can be consolidated into solid compacts having minimal oxygen content. A procedure for synthesizing these powders through gas-phase combustion is described. This novel approach involves reacting AlCl3, NH3, and Na vapors. Equilibrium thermodynamic calculations show that 100% yields can be obtained for these reactants with the products being AlN, NaCl, and H2. The NaCl by-product is used to coat the AlN particles in situ. The coating allows for control of AlN agglomeration and protects the powders from hydrolysis during post-flame handling. On the basis of thermodynamic and kinetic considerations, two different approaches were employed to produce the powder, in co-flow diffusion flame configurations. In the first approach, the three reactants were supplied in separate streams. In the second, the AlCl3 and NH3 were premixed with HCl and then reacted with Na vapor. X-ray diffraction (XRD) spectra of as-produced powders show only NaCl for the first case and NaCl and AlN for the second. After annealing at 775 C tinder dynamic vacuum, the salt was removed and XRD spectra of powders from both approaches show only AlN. Aluminum metal was also produced in the co-flow flame by reacting AlCl3 with Na. XRD spectra of as-produced powders show the products to be only NaCl and elemental aluminum.

  13. Microbial hydrogenogenic CO conversions: applications in synthesis gas purification and biodesulfurization

    NARCIS (Netherlands)

    Sipma, J.

    2006-01-01

    Hydrogen gas attracts great interest as a potential clean future fuel and it is an excellent electron donor in biotechnological reductive processes, e.g. in biodesulfurization. Bulk production of H 2 relies on the conversion of organic matter into synthesis gas, a mixture of H

  14. Microbial aspects of synthesis gas fed bioreactors treating sulfate and metal rich wastewaters

    NARCIS (Netherlands)

    Houten, van B.H.G.W.

    2006-01-01

    The use of synthesis gas fed sulfate-reducing bioreactors to simultaneously remove both oxidized sulfur compounds and metals shows great potential to treat wastewaters generated as a result of flue gas scrubbing, mining activities and galvanic processes. Detailed information about the phylogenetic

  15. Techno-economic analysis for the evaluation of three UCG synthesis gas end use approaches

    Science.gov (United States)

    Nakaten, Natalie; Kempka, Thomas; Burchart-Korol, Dorota; Krawczyk, Piotr; Kapusta, Krzysztof; Stańczyk, Krzysztof

    2016-04-01

    Underground coal gasification (UCG) enables the utilization of coal reserves that are economically not exploitable because of complex geological boundary conditions. In the present study we investigate UCG as a potential economic approach for conversion of deep-seated coals into a synthesis gas and its application within three different utilization options. Related to geological boundary conditions and the chosen gasification agent, UCG synthesis gas composes of varying methane, hydrogen, nitrogen, carbon monoxide and carbon dioxide amounts. In accordance to its calorific value, the processed UCG synthesis gas can be utilized in different manners, as for electricity generation in a combined cycle power plant or for feedstock production making use of its various chemical components. In the present study we analyze UCG synthesis gas utilization economics in the context of clean electricity generation with an integrated carbon capture and storage process (CCS) as well as synthetic fuel and fertilizer production (Kempka et al., 2010) based on a gas composition achieved during an in situ UCG trial in the Wieczorek Mine. Hereby, we also consider chemical feedstock production in order to mitigate CO2 emissions. Within a sensitivity analysis of UCG synthesis gas calorific value variations, we produce a range of capital and operational expenditure bandwidths that allow for an economic assessment of different synthesis gas end use approaches. To carry out the integrated techno-economic assessment of the coupled systems and the sensitivity analysis, we adapted the techno-economic UCG-CCS model developed by Nakaten et al. (2014). Our techno-economic modeling results demonstrate that the calorific value has a high impact on the economics of UCG synthesis gas utilization. In the underlying study, the synthesis gas is not suitable for an economic competitive electricity generation, due to the relatively low calorific value of 4.5 MJ/Nm³. To be a profitable option for electricity

  16. Comparison tests, in a pilot plant, of the performance of a coal-derived granular activated carbon: a comparison with coconut husk derived activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, S.; Kasahara, A.; Tsuruzono, Y.; Gotoh, M.

    1986-01-01

    A 160 m/sup 3//d pilot plant has been used in a series of comparison tests of the performance of coal-derived and coconut husk derived activated carbons. Activated carbons are used to remove trihalomethane precursors and malodorous substances from city water. A higher mean removal of coloration and COD/sub M//sub n/ was achieved with the coal-derived carbon (by factors of 1.5 and 1.8, respectively). The two activated carbons gave similar performances as regards turbidity, alkalinity, total iron and total manganese. 4 figures, 5 tables.

  17. Catalytic hydrotreatment of Illinois No. 6 coal-derived naphtha: comparison of molybdenum nitride and molybdenum sulfide for heteroatom removal

    Energy Technology Data Exchange (ETDEWEB)

    Raje, A.; Liaw, S.J.; Chary, K.V.R.; Davis, B.H. [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

    1995-03-16

    The hydrotreatment of naphtha derived from Illinois No. 6 coal was investigated using molybdenum sulfide and nitride catalysts. The two catalysts are compared on the basis of total catalyst weight. Molybdenum sulfide is more active than molybdenum nitride for hydrodesulfurization (HDS) of a coal-derived naphtha. The rate of hydrodeoxygenation (HDO) of the naphtha over both catalysts are comparable. For hydrodenitrogenation (HDN), the sulfide is more active than the nitride only at higher temperatures ({gt}325{degree}C). Based upon conversion data, the naphtha can be lumped into a reactive and a less reactive fraction with each following first-order kinetics for heteroatom removal. The HDS and HDN rates and activation energies of the less reactive lump are smaller for the nitride than for the sulfide catalyst.

  18. Potential of synthesis gas production from rubber wood chip gasification in a bubbling fluidised bed gasifier

    International Nuclear Information System (INIS)

    Kaewluan, Sommas; Pipatmanomai, Suneerat

    2011-01-01

    Experiments of rubber wood chip gasification were carried out in a 100-kW th bubbling fluidised bed gasifier to investigate the effect of air to fuel ratio (represented as equivalence ratio - ER) on the yield and properties of synthesis gas. For all experiments, the flow rate of ambient air was fixed, while the feed rate of rubber wood chip was adjusted to vary ER in the range of 0.32-0.43. Increasing ER continuously raised the bed temperature, which resulted in higher synthesis gas yield and lower yield of ash and tar. However, higher ER generally gave synthesis gas of lower heating value, partly due to the dilution of N 2 . Considering the energy efficiency of the process, the optimum operation was achieved at ER = 0.38, which yielded 2.33 Nm 3 of synthesis gas per kg of dry biomass at the heating value of 4.94 MJ/Nm 3 . The calculated carbon conversion efficiency and gasification efficiency were 97.3% and 80.2%, respectively. The mass and energy balance of the gasification process showed that the mass and energy distribution was significantly affected by ER and that the energy losses accounted for ∼25% of the total output energy. The economical assessment of synthesis gas utilisation for heat and electricity production based on a 1-MW th bubbling fluidised bed gasifier and the operational data resulting from the rubber wood chip gasification experiments in this study clearly demonstrated the attractiveness of replacing heavy fuel oil and natural gas by the synthesis gas for heat applications in terms of 70% and 50% annual saving of fuel cost, respectively. However, the case of electricity production does not seem a preferable option due to its current technical and non-technical barriers.

  19. Fuel from the synthesis gas - the role of process engineering

    Energy Technology Data Exchange (ETDEWEB)

    Stelmachowski, Marek; Nowicki, Lech [Technical Univ. of Lodz, Dept. of Environmental Engineering Systems, Lodz (Poland)

    2003-02-01

    The paper presents the conclusions obtained in the investigations of methanol synthesis, Fischer-Tropsch synthesis, and higher alcohols synthesis from syngas as a raw material in slurry reactors. The overview of the role of process engineering was made on the basis of the experience in optimizing process conditions, modeling reactors and working out new technologies. Experimental data, obtained with a laboratory-stirred autoclave and theoretical considerations were used to develop the kinetic models that can describe the product formation and the model of the simultaneous phase and chemical equilibrium for the methanol and Fischer-Tropsch syntheses in the slurry reactors. These models were employed in modeling of the bubble-column slurry reactor (BCSR). Based on these considerations, a computer simulation of the low-pressure methanol synthesis for the pilot-scale, BCSR, was devised. The results of the calculations and the conclusions could be employed in the process for designing an industrial plant. (Author)

  20. Literature Review and Synthesis for the Natural Gas Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Folga, Stephen [Argonne National Lab. (ANL), Argonne, IL (United States); Talaber, Leah [Argonne National Lab. (ANL), Argonne, IL (United States); McLamore, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Kraucunas, Ian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McPherson, Timothy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parrott, Lori [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Manzanares, Trevor [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-06-01

    The efficient and effective movement of natural gas from producing regions to consuming regions requires an extensive and elaborate transportation system. In many instances, natural gas produced from a particular well has to travel a great distance to reach its point of use. The transportation system for natural gas consists of a complex network of pipelines designed to quickly and efficiently transport the gas from its origin to areas of high demand. The transportation of natural gas is closely linked to its storage: If the natural gas being transported is not immediately required, it can be put into storage facilities until it is needed. A description of the natural gas transmission, storage, and distribution (TS&D) sector is provided as follows.

  1. Characterization of coal-derived liquids and other fossil-fuel-related materials employing mass spectrometry. Final report, September 30, 1976-September 29, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Scheppele, S E

    1982-05-01

    A document was prepared which assessed the state-of-the art in the mass spectrometric characterization of fossil fuel materials and the relevance of these data to the fossil fuel industry. A Kratos DS50 SM data system was successfully interfaced to a CEC 21-110B mass spectrometer. Communications between the NOVA 3/12 computer in the data system and the OSU central computer were established. A Grant Comparator/Microdensitometer was acquired and made operational. Plans were developed and hardware acquired for interfacing the densitometer to the NOVA 3/12 computer. A quartz direct introduction probe was acquired for the CEC 21-110B. A temperature controller for the probe was acquired and interfaced to the slow speed ADC on the auxillary board in the data system/mass spectrometer interface. The combined FI/EI source was modified to operate in the FD mode and an apparatus was fabricated for conditioning FD emitters. A CSI supergrater 3 was interfaced to the PE 3920 gas chromatograph. The upgraded facility was used to develop mass spectrometric methods for the characterization of fossil fuel materials and to apply methods to the characterization of these materials. Activities included: (1) initial development of field-ionization mass spectrometry for the characterization of saturated hydrocarbons, (2) computerization of the technique of probe microdistillation/mass spectrometry, (3) initation of the development of a new method for the computer assisted assignment of formulas to ion masses, (4) characterization of neutral fractions from a hydrotreated tar-sands oil, and (5) characterization of coal-derived oils and asphaltenes.

  2. Synthesis of Nanoparticles in a Pulsed-Periodic Gas Discharge and Their Potential Applications

    Science.gov (United States)

    Ivanov, V. V.; Efimov, A. A.; Myl'nikov, D. A.; Lizunova, A. A.

    2018-03-01

    Conditions for the synthesis of three types nanoparticles (SnO2, Al2O3, and Ag) with typical sizes in the range of 4 to 10 nm and a performance of 0.4 g/h are employed in a pulsed-periodic gas discharge in an atmosphere of air. Spherical Ge nanoparticles with a characteristic size of 13 nm are synthesized by these means for the first time with a performance of around 10 mg/h. The specific energy consumption in the synthesis of nanoparticles is for these materials in the range of 2000 to 5000 kW h/kg. The prospects for using tinoxide nanoparticles in sensor components and jets of silver nanoparticles for aerosol printing are discussed. The merits and demerits of the pulsed gas-discharge method among other gas-phase approaches to the synthesis of nanoparticles are analyzed for the current level of development.

  3. Incorporation of catalytic dehydrogenation into fischer-tropsch synthesis to significantly reduce carbon dioxide emissions

    Science.gov (United States)

    Huffman, Gerald P.

    2012-11-13

    A new method of producing liquid transportation fuels from coal and other hydrocarbons that significantly reduces carbon dioxide emissions by combining Fischer-Tropsch synthesis with catalytic dehydrogenation is claimed. Catalytic dehydrogenation (CDH) of the gaseous products (C1-C4) of Fischer-Tropsch synthesis (FTS) can produce large quantities of hydrogen while converting the carbon to multi-walled carbon nanotubes (MWCNT). Incorporation of CDH into a FTS-CDH plant converting coal to liquid fuels can eliminate all or most of the CO.sub.2 emissions from the water-gas shift (WGS) reaction that is currently used to elevate the H.sub.2 level of coal-derived syngas for FTS. Additionally, the FTS-CDH process saves large amounts of water used by the WGS reaction and produces a valuable by-product, MWCNT.

  4. Effects of coal-derived trace species on the performance of molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Pigeaud, A.

    1991-10-01

    The overall objective of the present study was to determine in detail the interaction effects of 10 simultaneously present, coal-gas contaminants, both on each other and on components of the Carbonate Fuel Cell. The primary goal was to assess underlying chemistries and reaction mechanisms which may cause decay in fuel cell performance or endurance as a result of both physics-chemical and/or mechanical interactions with the cell components and internal fuel cell parts. It was found, both from theory and cell test evidence, that trace contaminant interactions may occur with: Fuel-cell Electrodes (e.g., in this study with the Ni-anode), Lithium/Potassium Carbonate Electrolyte, Nickel and SS-Hardware, and by Mechanical Obstruction of Gas Flow in the Anode Plenum.

  5. Ozone Synthesis Efficiency Upgrading in the Pulsed Point-to-Plane Gas Discharge

    International Nuclear Information System (INIS)

    Golota, V.I.; Zavada, L.M.; Kotyukov, O.V.; Polyakov, A.V.; Pugach, S.G.

    2006-01-01

    Results are reported from the studies into electrodynamic characteristics of the barrierless point-to-plane gas discharge as a HV pulse of positive polarity is applied to the point electrode. The efficiency of ozone synthesis has been determined as a function of the length and repetition frequency of the HV pulse. It has been demonstrated that the electrodynamic characteristics of the discharge and the efficiency of ozone synthesis in oxygen-containing gas mixtures essentially depend on the parameters of HV power supply. The HV switch HTS-300 (BEHLKE Electronic GmbH) was used for HV pulse shaping

  6. The direct conversion of synthesis gas to chemicals / Ernest du Toit

    OpenAIRE

    Du Toit, Ernest

    2002-01-01

    The catalytic conversion of synthesis gas, obtainable from the processing of coal, biomass or natural gas, to a complex hydrocarbon product stream can be achieved via the Fischer-Tropsch process. The Fischer-Tropsch synthesis process has evolved from being mainly a fuel producing process in the early 1950's to that of a solvent and speciality wax production process towards the end of the 1970's. From the early 1980's there has been a clear shift towards the production of commod...

  7. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Dady B. Dadyburjor; Mark E. Heavner; Manoj Katakdaunde; Liviu Magean; J. Joshua Maybury; Alfred H. Stiller; Joseph M. Stoffa; John W. Zondlo

    2006-08-01

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, and porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, hydrotreatment of solvent was completed in preparation for pitch fabrication for graphite electrodes. Coal digestion has lagged but is expected to be complete by next quarter. Studies are reported on coal dissolution, pitch production, foam synthesis using physical blowing agents, and alternate coking techniques.

  8. Development of disposal sorbents for chloride removal from high-temperature coal-derived gases

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, G.N.; Wood, B.J.; Canizales, A. [and others

    1995-11-01

    The objective of this program is to develop alkali-based disposable sorbents capable of reducing HCl vapor concentrations to less than 1 ppmv in coal gas streams at temperatures in the range 400{degrees} to 750{degrees}C and pressures in the range 1 to 20 atm. The primary areas of focus of this program are investigation of different processes for fabricating the sorbents, testing their suitability for different reactor configurations, obtaining kinetic data for commercial reactor design, and updating the economics of the process.

  9. The Late Paleozoic relative gas fields of coal measure in China and their significances on the natural gas industry

    Directory of Open Access Journals (Sweden)

    Chenchen Fang

    2016-12-01

    Full Text Available The coal measure gas sources of coal-derived gas fields in the Late Paleozoic China are the Lower Carboniferous Dishuiquan Formation, the Upper Carboniferous Batamayineishan Formation and Benxi Formation, the Lower Permian Taiyuan Formation and Shanxi Formation, and the Upper Permian Longtan Formation. The coal-derived gas accumulates in Ordovician, Carboniferous, Permian, and Paleocene reservoirs and are distributed in Ordos Basin, Bohai Bay Basin, Junggar Basin, and Sichuan Basin. There are 16 gas fields and 12 of them are large gas fields such as the Sulige large gas field which is China's largest reserve with the highest annual output. According to component and alkane carbon isotope data of 99 gas samples, they are distinguished to be coal-derived gas from coal-derived gas with δ13C2 > −28.5‰ and δ13C1 -δ13C2 -δ13C3 identification chart. The Late Paleozoic relative gas fields of coal measure are significant for the Chinese natural gas industry: proven natural gas geological reserves and annual output of them account for 1/3 in China, and the gas source of three significant large gas fields is coal-derived, which of five significant large gas fields supporting China to be a great gas producing country. The average reserves of the gas fields and the large gas fields formed from the late Paleozoic coal measure are 5.3 and 1.7 times that of the gas fields and the large gas fields in China.

  10. Synthesis and characterization of porous silicon gas sensors

    Science.gov (United States)

    abbas, Roaa A.; Alwan, Alwan M.; Abdulhamied, Zainab T.

    2018-05-01

    In this work, photo-electrochemical etching process of n-type Silicon of resistivity(10 Ω.cm) and (100) orientation, using two illumination sources IR and violet wavelength in HF acid have been used to produce PSi gas detection device. The fabrication process was carried out at a fixed etching current density of 25mA/cm2 and at different etching time (5, 10, 15 and 20) min and (8, 16, 24, and 30) min. Two configurations of gas sensor configuration planer and sandwich have been made and investigated. The morphological properties have been studied using SEM,the FTIR measurement show that the (Si-Hx) and (Si-O-Si) absorption peak were increases with increasing etching time,and Photoluminescence properties of PSi layer show decrease in the peak of PL peak toward the violet shift. The gas detection process is made on the CO2 gas at different operating temperature and fixed gas concentration. In the planner structure, the gas sensing was measured through, the change in the resistance readout as a function to the exposure time, while for sandwich structure J-V characteristic have been made to determine the sensitivity.

  11. DEVELOPMENT OF DISPOSABLE SORBENTS FOR CHLORIDE REMOVAL FROM HIGH TEMPERATURE COAL-DERIVED GASES

    Energy Technology Data Exchange (ETDEWEB)

    Gopala Krishnan; Raghubir Gupta

    1999-09-01

    Advanced integrated-gasification combined-cycle (IGCC) and integrated-gasification fuel cell (IGFC) systems require the development of high temperature sorbents for the removal of hydrogen chloride (HCl) vapor to less than 1 parts-per-million (ppm) levels. HCl is a highly reactive, corrosive, and toxic gas which must be removed to meet environmental regulations, to protect power generation equipment, and to minimize deterioration of hot gas desulfurization sorbents. The objective of this program was to develop disposable, alkali-based sorbents capable of reducing HCl vapor levels to less than 1 ppm in the temperature range from 400 to 750 C and pressures in the range from 1 to 20 atm. The primary areas of focus of this program were to investigate different methods of sorbent fabrication, testing their suitability for different reactor configurations, obtaining reaction kinetics data, and conducting a preliminary economic feasibility assessment. This program was a joint effort between SRI International (SRI), Research Triangle Institute (RTI), and General Electric Corporate Research and Development (GE-CRD). SRI, the prime contractor and RTI, a major subcontractor, performed most of the work in this program. Thermochemical calculations indicated that sodium-based sorbents were capable of reducing HCl vapor levels to less than 1 ppm at temperatures up to 650 C, but the regeneration of spent sorbents would require complex process steps. Nahcolite (NaHCO{sub 3}), a naturally-occurring mineral, could be used as an inexpensive sorbent to remove HCl vapor in hot coal gas streams. In the current program, nahcolite powder was used to fabricate pellets suitable for fixed-bed reactors and granules suitable for fluidized-bed reactors. Pilot-scale equipment were used to prepare sorbents in large batches: pellets by disk pelletization and extrusion techniques, and granules by granulation and spray-drying techniques. Bench-scale fixed- and fluidized-bed reactors were assembled at

  12. Reaction scheme of partial oxidation of methane to synthesis gas over yttrium-stabilized zirconia

    NARCIS (Netherlands)

    Zhu, J.J.; van Ommen, J.G.; Lefferts, Leonardus

    2004-01-01

    The partial oxidation of methane to synthesis gas over yttrium-stabilized zirconia (YSZ) was studied with in situ FTIR and both steady-state and transient experiments. The four major products, CO, H2, CO2, and H2O, are primary products of CPOM over YSZ. Besides these major products and traces of

  13. Alternate fuels and chemicals from synthesis gas: Vinyl acetate monomer. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Richard D. Colberg; Nick A. Collins; Edwin F. Holcombe; Gerald C. Tustin; Joseph R. Zoeller

    1999-01-01

    There has been a long-standing desire on the part of industry and the U.S. Department of Energy to replace the existing ethylene-based vinyl acetate monomer (VAM) process with an entirely synthesis gas-based process. Although there are a large number of process options for the conversion of synthesis gas to VAM, Eastman Chemical Company undertook an analytical approach, based on known chemical and economic principles, to reduce the potential candidate processes to a select group of eight processes. The critical technologies that would be required for these routes were: (1) the esterification of acetaldehyde (AcH) with ketene to generate VAM, (2) the hydrogenation of ketene to acetaldehyde, (3) the hydrogenation of acetic acid to acetaldehyde, and (4) the reductive carbonylation of methanol to acetaldehyde. This report describes the selection process for the candidate processes, the successful development of the key technologies, and the economic assessments for the preferred routes. In addition, improvements in the conversion of acetic anhydride and acetaldehyde to VAM are discussed. The conclusion from this study is that, with the technology developed in this study, VAM may be produced from synthesis gas, but the cost of production is about 15% higher than the conventional oxidative acetoxylation of ethylene, primarily due to higher capital associated with the synthesis gas-based processes.

  14. Methanol synthesis in a countercurrent gas-solid-solid trickle flow reactor. An experimental study

    NARCIS (Netherlands)

    Kuczynski, M.; Oyevaar, M.H.; Pieters, R.T.; Westerterp, K.R.

    1987-01-01

    The synthesis of methanol from CO and H2 was executed in a gas-solid-solid trickle flow reactor. The reactor consisted of three tubular reactor sections with cooling sections in between. The catalyst was Cu on alumina, the adsorbent was a silica-alumina powder and the experimental range 498–523 K,

  15. Preliminary assessment of synthesis gas production via hybrid steam reforming of methane and glycerol

    NARCIS (Netherlands)

    Balegedde Ramachandran, P.; van Rossum, G.; Kersten, Sascha R.A.; van Swaaij, Willibrordus Petrus Maria

    2012-01-01

    In this article, hybrid steam reforming (HSR) of desulphurized methane, together with crude glycerol, in existing commercial steam reformers to produce synthesis gas is proposed. The proposed concept consists of a gasifier to produce vapors, gases, and char from crude glycerol, which is coupled with

  16. Environmental Transmission Electron Microscopy (ETEM) Studies of Single Iron Nanoparticle Carburization in Synthesis Gas

    DEFF Research Database (Denmark)

    Liu, Xi; Zhang, Chenghua; Li, Yongwang

    2017-01-01

    Structuralevolution of iron nanoparticles involving the formationand growth of iron carbide nuclei in the iron nanoparticle was directlyvisualized at the atomic level, using environmental transmission electronmicroscopy (TEM) under reactive conditions mimicking Fischer–Tropschsynthesis. Formation...... and electronenergy-loss spectra provides a detailed picture from initial activationto final degradation of iron under synthesis gas....

  17. Synthesis, characterization and gas sensing performance of SnO2 ...

    Indian Academy of Sciences (India)

    Synthesis, characterization and gas sensing performance of SnO2 thin films prepared by spray pyrolysis. GANESH E PATIL, D D KAJALE, D N CHAVAN†, N K PAWAR††, P T AHIRE, S D SHINDE#,. V B GAIKWAD# and G H JAIN. ∗. Materials Research Laboratory, Arts, Commerce and Science College, Nandgaon 423 106, ...

  18. Some new techniques in tritium gas handling as applied to metal hydride synthesis

    International Nuclear Information System (INIS)

    Nasise, J.E.

    1988-01-01

    A state-of-the-art tritium Hydriding Synthesis System (HSS) was designed and built to replace the existing system within the Tritium Salt Facility (TSF) at the Los Alamos National Laboratory. This new hydriding system utilizes unique fast-cycling 7.9 mole uranium beds (47.5g of T at 100% loading) and novel gas circulating hydriding furnaces. Tritium system components discussed include fast-cycling uranium beds, circulating gas hydriding furnaces, valves, storage volumes, manifolds, gas transfer pumps, and graphic display and control consoles. Many of the tritium handling and processing techniques incorporated into this system are directly applicable to today's fusion fuel loops. 12 refs., 7 figs

  19. Ultrasonic experiment on hydrate formation of a synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Shicai; Fan, Shuanshi; Liang, Deqing; Zhang, Junshe; Feng, Ziping

    2005-07-01

    The effect of ultrasonic on the induction time and formation rate of natural gas hydrates was investigated in a stainless steel cell in this study. The results show that the induction time with ultrasonic was about 1/6 of that without ultrasonic and only about 1/10 if rehydration after decomposition in water-gas system. In sodium dodecyl sulfate (SDS) solution-gas system, the critical micellar concentration (CMC) was not identified with ultrasonic. The formation rate and storage capacity of hydrate increased with increasing SDS concentration at a range of 0 to 800ppm. However, the increase was insignificant as the SDS concentration increased from 600 to 800ppm, (Author)

  20. Bimetallic Nanocatalysts in Mesoporous Silica for Hydrogen Production from Coal-Derived Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Kuila, Debasish [North Carolina Agricultural & Technical State Univ., Greensboro, NC (United States); Ilias, Shamsuddin [North Carolina Agricultural & Technical State Univ., Greensboro, NC (United States)

    2013-02-13

    In steam reforming reactions (SRRs) of alkanes and alcohols to produce H2, noble metals such as platinum (Pt) and palladium (Pd) are extensively used as catalyst. These metals are expensive; so, to reduce noble-metal loading, bi-metallic nanocatalysts containing non-noble metals in MCM-41 (Mobil Composition of Material No. 41, a mesoporous material) as a support material with high-surface area were synthesized using one-pot hydrothermal procedure with a surfactant such as cetyltrimethylammonium bromide (CTAB) as a template. Bi-metallic nanocatalysts of Pd-Ni and Pd-Co with varying metal loadings in MCM-41 were characterized by x-ray diffraction (XRD), N2 adsorption, and Transmission electron microscopy (TEM) techniques. The BET surface area of MCM-41 (~1000 m2/g) containing metal nanoparticles decreases with the increase in metal loading. The FTIR studies confirm strong interaction between Si-O-M (M = Pd, Ni, Co) units and successful inclusion of metal into the mesoporous silica matrix. The catalyst activities were examined in steam reforming of methanol (SRM) reactions to produce hydrogen. Reference tests using catalysts containing individual metals (Pd, Ni and Co) were also performed to investigate the effect of the bimetallic system on the catalytic behavior in the SRM reactions. The bimetallic system remarkably improves the hydrogen selectivity, methanol conversion and stability of the catalyst. The results are consistent with a synergistic behavior for the Pd-Ni-bimetallic system. The performance, durability and thermal stability of the Pd-Ni/MCM-41 and Pd-Co/MCM-41 suggest that these materials may be promising catalysts for hydrogen production from biofuels. A part of this work for synthesis and characterization of Pd-Ni-MCM-41 and its activity for SRM reactions has been published (“Development of Mesoporous Silica Encapsulated Pd-Ni Nanocatalyst for Hydrogen Production” in “Production and Purification of Ultraclean

  1. Preparation and evaluation of coal-derived activated carbons for removal of mercury vapor from simulated coal combustion flue fases

    Science.gov (United States)

    Hsi, H.-C.; Chen, S.; Rostam-Abadi, M.; Rood, M.J.; Richardson, C.F.; Carey, T.R.; Chang, R.

    1998-01-01

    Coal-derived activated carbons (CDACs) were tested for their suitability in removing trace amounts of vapor-phase mercury from simulated flue gases generated by coal combustion. CDACs were prepared in bench-scale and pilot-scale fluidized-bed reactors with a three-step process, including coal preoxidation, carbonization, and then steam activation. CDACs from high-organicsulfur Illinois coals had a greater equilibrium Hg0 adsorption capacity than activated carbons prepared from a low-organic-sulfur Illinois coal. When a low-organic-sulfur CDAC was impregnated with elemental sulfur at 600 ??C, its equilibrium Hg0 adsorption capacity was comparable to the adsorption capacity of the activated carbon prepared from the high-organicsulfur coal. X-ray diffraction and sulfur K-edge X-ray absorption near-edge structure examinations showed that the sulfur in the CDACs was mainly in organic forms. These results suggested that a portion of the inherent organic sulfur in the starting coal, which remained in the CDACs, played an important role in adsorption of Hg0. Besides organic sulfur, the BET surface area and micropore area of the CDACs also influenced Hg0 adsorption capacity. The HgCl2 adsorption capacity was not as dependent on the surface area and concentration of sulfur in the CDACs as was adsorption of Hg0. The properties and mercury adsorption capacities of the CDACs were compared with those obtained for commercial Darco FGD carbon.

  2. Synthesis, Characterization, and Gas Sensing Applications of WO3 Nanobricks

    Science.gov (United States)

    Xiao, Jingkun; Song, Chengwen; Dong, Wei; Li, Chen; Yin, Yanyan; Zhang, Xiaoni; Song, Mingyan

    2015-08-01

    WO3 nanobricks are fabricated by a simple hydrothermal method. Morphology and structure of the WO3 nanobricks are characterized by scanning electron microscopy and x-ray diffraction. Gas sensing properties of the as-prepared WO3 sensor are systematically investigated by a static gas sensing system. The results show that the WO3 nanobricks with defect corners demonstrate good crystallinity, and the mean edge length and wall thickness are 1-1.5 and 400 nm, respectively. The WO3 sensor achieves its maximum sensitivity to 100 ppm ethanol at the optimal operating temperature of 300 °C. Ultra-fast response time (2-3 s) and fast recovery time (4-11 s) of the WO3 sensor toward 100 ppm ethanol are also observed at this optimal operating temperature. Moreover, the WO3 sensor exhibits high selectivity to other gases such as methanol, benzene, hexane, and dichloromethane, indicating its excellent potential application as a gas sensor for ethanol detection.

  3. Refinery Integration of By-Products from Coal-Derived Jet Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Caroline Clifford; Andre Boehman; Chunshan Song; Bruce Miller; Gareth Mitchell

    2008-03-31

    designed for natural gas/fuel oil, and determining the boiler performance when firing the five fuels. Two different co-processed fuel oils were tested: one that had been partially hydrotreated, and the other a product of fractionation before hydrotreating. Task 5 focused on examining refining methods that would utilize coal and produce thermally stable jet fuel, included delayed coking and solvent extraction. Delayed coking was done on blends of decant oil and coal, with the goal to produce a premium carbon product and liquid fuels. Coking was done on bench scale and large laboratory scale cokers. Two coals were examined for co-coking, using Pittsburgh seam coal and Marfork coal product. Reactions in the large, laboratory scaled coker were reproducible in yields of products and in quality of products. While the co-coke produced from both coals was of sponge coke quality, minerals left in the coke made it unacceptable for use as anode or graphite grade filler.

  4. Atmospheric-pressure dielectric barrier discharge with capillary injection for gas-phase nanoparticle synthesis

    International Nuclear Information System (INIS)

    Ghosh, Souvik; Liu, Tianqi; Bilici, Mihai; Cole, Jonathan; Huang, I-Min; Sankaran, R Mohan; Staack, David; Mariotti, Davide

    2015-01-01

    We present an atmospheric-pressure dielectric barrier discharge (DBD) reactor for gas-phase nanoparticle synthesis. Nickel nanoparticles are synthesized by homogenous nucleation from nickelocene vapor and characterized online by aerosol mobility measurements. The effects of residence time and precursor concentration on particle growth are studied. We find that narrower distributions of smaller particles are produced by decreasing the precursor concentration, in agreement with vapor nucleation theory, but larger particles and aggregates form at higher gas flow rates where the mean residence time should be reduced, suggesting a cooling effect that leads to enhanced particle nucleation. In comparison, incorporating a capillary gas injector to alter the velocity profile is found to significantly reduce particle size and agglomeration. These results suggest that capillary gas injection is a better approach to decreasing the mean residence time and narrowing the residence time distribution for nanoparticle growth by producing a sharp and narrow velocity profile. (paper)

  5. SnO2 Nanostructure as Pollutant Gas Sensors: Synthesis, Sensing Performances, and Mechanism

    Directory of Open Access Journals (Sweden)

    Brian Yuliarto

    2015-01-01

    Full Text Available A significant amount of pollutants is produced from factories and motor vehicles in the form of gas. Their negative impact on the environment is well known; therefore detection with effective gas sensors is important as part of pollution prevention efforts. Gas sensors use a metal oxide semiconductor, specifically SnO2 nanostructures. This semiconductor is interesting and worthy of further investigation because of its many uses, for example, as lithium battery electrode, energy storage, catalyst, and transistor, and has potential as a gas sensor. In addition, there has to be a discussion of the use of SnO2 as a pollutant gas sensor especially for waste products such as CO, CO2, SO2, and NOx. In this paper, the development of the fabrication of SnO2 nanostructures synthesis will be described as it relates to the performances as pollutant gas sensors. In addition, the functionalization of SnO2 as a gas sensor is extensively discussed with respect to the theory of gas adsorption, the surface features of SnO2, the band gap theory, and electron transfer.

  6. Impact of Contaminants Present in Coal-Biomass Derived Synthesis Gas on Water-gas Shift and Fischer-Tropsch Synthesis Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Alptekin, Gokhan [TDA Research, Inc., Wheat Ridge, CO (United States)

    2013-02-15

    Co-gasification of biomass and coal in large-scale, Integrated Gasification Combined Cycle (IGCC) plants increases the efficiency and reduces the environmental impact of making synthesis gas ("syngas") that can be used in Coal-Biomass-to-Liquids (CBTL) processes for producing transportation fuels. However, the water-gas shift (WGS) and Fischer-Tropsch synthesis (FTS) catalysts used in these processes may be poisoned by multiple contaminants found in coal-biomass derived syngas; sulfur species, trace toxic metals, halides, nitrogen species, the vapors of alkali metals and their salts (e.g., KCl and NaCl), ammonia, and phosphorous. Thus, it is essential to develop a fundamental understanding of poisoning/inhibition mechanisms before investing in the development of any costly mitigation technologies. We therefore investigated the impact of potential contaminants (H2S, NH3, HCN, AsH3, PH3, HCl, NaCl, KCl, AS3, NH4NO3, NH4OH, KNO3, HBr, HF, and HNO3) on the performance and lifetime of commercially available and generic (prepared in-house) WGS and FT catalysts.

  7. Boron-containing catalysts for dry reforming of methane to synthesis gas

    KAUST Repository

    Takanabe, Kazuhiro

    2018-01-04

    The present invention uses a cobalt catalyst for carbon dioxide reforming of lower alkanes to synthesis gas having a cobalt catalyst on an oxide support where the supported cobalt catalyst has been modified with a boron precursor. The boron-treated cobalt catalyst systems as described herein show significant increases in the conversion of CH4 and CO2 during the dry reforming of methane (DRM) reaction as compared to traditional catalysts. Described herein are supported catalysts and methods of using the catalysts for the dry reforming of methane to synthesis gas, with the supported catalysts in the present invention include a boron-treated cobalt catalyst disposed on an oxide support. Also described herein are processes for preparing the supported catalysts.

  8. Numerical investigation of high temperature synthesis gas premixed combustion via ANSYS Fluent

    Directory of Open Access Journals (Sweden)

    Pashchenko Dmitry

    2018-01-01

    Full Text Available A numerical model of the synthesis gas pre-mixed combustion is developed. The research was carried out via ANSYS Fluent software. Verification of the numerical results was carried out using experimental data. A visual comparison of the flame contours that obtained by the synthesis gas combustion for Re = 600; 800; 1000 was performed. A comparison of the wall temperature of the combustion chamber, obtained with the help of the developed model, with the results of a physical experiment was also presented. For all cases, good convergence of the results is observed. It is established that a change in the temperature of the syngas/air mixture at the inlet to the combustion chamber does not significantly affect the temperature of the combustion products due to the dissipation of the H2O and CO2 molecules. The obtained results are of practical importance for the design of heat engineering plants with thermochemical heat recovery.

  9. Synthesis and Gas Phase Thermochemistry of Germanium-Containing Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Classen, Nathan Robert [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    The driving force behind much of the work in this dissertation was to gain further understanding of the unique olefin to carbene isomerization observed in the thermolysis of 1,1-dimethyl-2-methylenesilacyclobutane by finding new examples of it in other silicon and germanium compounds. This lead to the examination of a novel phenylmethylenesilacyclobut-2-ene, which did not undergo olefin to carbene rearrangement. A synthetic route to methylenegermacyclobutanes was developed, but the methylenegermacyclobutane system exhibited kinetic instability, making the study of the system difficult. In any case the germanium system decomposed through a complex mechanism which may not include olefin to carbene isomerization. However, this work lead to the study of the gas phase thermochemistry of a series of dialkylgermylene precursors in order to better understand the mechanism of the thermal decomposition of dialkylgermylenes. The resulting dialkylgermylenes were found to undergo a reversible intramolecular β C-H insertion mechanism.

  10. Oil-shale gasification for obtaining of gas for synthesis of aliphatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Strizhakova, Yu. [Samara State Univ. (Russian Federation); Avakyan, T.; Lapidus, A.L. [I.M. Gubkin Russian State Univ. of Oil and Gas, Moscow (Russian Federation)

    2011-07-01

    Nowadays, the problem of qualified usage of solid fossil fuels as raw materials for obtaining of motor fuels and chemical products is becoming increasingly important. Gasification with further processing of gaseous products is a one of possible ways of their use. Production of synthesis gas with H{sub 2}/CO ratio equal 2 is possible by gasification of oil-shale. This gas is converted into the mixture of hydrocarbons over cobalt catalyst at temperature from 160 to 210 C at atmospheric pressure. The hydrocarbons can be used as motor, including diesel, or reactive fuel. (orig.)

  11. Electricity generation from synthesis gas by microbial processes: CO fermentation and microbial fuel cell technology.

    Science.gov (United States)

    Kim, Daehee; Chang, In Seop

    2009-10-01

    A microbiological process was established to harvest electricity from the carbon monoxide (CO). A CO fermenter was enriched with CO as the sole carbon source. The DGGE/DNA sequencing results showed that Acetobacterium spp. were enriched from the anaerobic digester fluid. After the fermenter was operated under continuous mode, the products were then continuously fed to the microbial fuel cell (MFC) to generate electricity. Even though the conversion yield was quite low, this study proved that synthesis gas (syn-gas) can be converted to electricity with the aid of microbes that do not possess the drawbacks of metal catalysts of conventional methods.

  12. Fischer Indole Synthesis in the Gas Phase, the Solution Phase, and at the Electrospray Droplet Interface.

    Science.gov (United States)

    Bain, Ryan M; Ayrton, Stephen T; Cooks, R Graham

    2017-07-01

    Previous reports have shown that reactions occurring in the microdroplets formed during electrospray ionization can, under the right conditions, exhibit significantly greater rates than the corresponding bulk solution-phase reactions. The observed acceleration under electrospray ionization could result from a solution-phase, a gas-phase, or an interfacial reaction. This study shows that a gas-phase ion/molecule (or ion/ion) reaction is not responsible for the observed rate enhancement in the particular case of the Fischer indole synthesis. The results show that the accelerated reaction proceeds in the microdroplets, and evidence is provided that an interfacial process is involved. Graphical Abstract GRAPHICAL ABSTRACT TEXT HERE] -->.

  13. Coal-Derived Warm Syngas Purification and CO2 Capture-Assisted Methane Production

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, Robert A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); King, David L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Xiaohong S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Xing, Rong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Spies, Kurt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhu, Yunhua [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rainbolt, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Liyu [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Braunberger, B. [Western Research Inst., Laramie, WY (United States)

    2014-10-01

    Gasifier-derived syngas from coal has many applications in the area of catalytic transformation to fuels and chemicals. Raw syngas must be treated to remove a number of impurities that would otherwise poison the synthesis catalysts. Inorganic impurities include alkali salts, chloride, sulfur compounds, heavy metals, ammonia, and various P, As, Sb, and Se- containing compounds. Systems comprising multiple sorbent and catalytic beds have been developed for the removal of impurities from gasified coal using a warm cleanup approach. This approach has the potential to be more economic than the currently available acid gas removal (AGR) approaches and improves upon currently available processes that do not provide the level of impurity removal that is required for catalytic synthesis application. Gasification also lends itself much more readily to the capture of CO2, important in the regulation and control of greenhouse gas emissions. CO2 capture material was developed and in this study was demonstrated to assist in methane production from the purified syngas. Simultaneous CO2 sorption enhances the CO methanation reaction through relaxation of thermodynamic constraint, thus providing economic benefit rather than simply consisting of an add-on cost for carbon capture and release. Molten and pre-molten LiNaKCO3 can promote MgO and MgO-based double salts to capture CO2 with high cycling capacity. A stable cycling CO2 capacity up to 13 mmol/g was demonstrated. This capture material was specifically developed in this study to operate in the same temperature range and therefore integrate effectively with warm gas cleanup and methane synthesis. By combining syngas methanation, water-gas-shift, and CO2 sorption in a single reactor, single pass yield to methane of 99% was demonstrated at 10 bar and 330°C when using a 20 wt% Ni/MgAl2O4 catalyst and a molten-phase promoted Mg

  14. TECHNICAL AND ECONOMICAL ASSESSMENT OF USING PEAT GAS SYNTHESIS IN POWER ENGINEERING

    OpenAIRE

    Карвацький, Антон Янович

    2016-01-01

    Nowadays more and more attention in the world is paid for technology of using low-calorie fuels. They are associated with the processes of pyrolysis, gasification, production of gas synthesis and diesel fuel.In general, gasification technology is developing very well. There are many examples of successful commercial and practical realization of such projects. Examples of such developments commercialization from using of gasification process for electricity and heat production can be used in s...

  15. Processes in petroleum chemistry. Technical and economical characteristics Vol. 1. Synthesis gas and derivatives. Main hydrocarbon intermediaries (2 ed. )

    Energy Technology Data Exchange (ETDEWEB)

    Chauvel, A.; Lefebvre, G.; Castex, L.

    1985-01-01

    The aim of this book is to give rudiments for a preliminary study to outline petrochemical operation and cost estimation. Basic operations are examined: Steam reforming or partial oxidation, steam or thermal cracking and catalytic reforming. The main topics examined include: hydrogen purification, hydrogen fabrication from hydrocarbons, carbonaceous materials or water, production of carbon monoxide, ammoniac synthesis methanol synthesis from synthesis gas, preparation of formol, urea, acetylene and monomers for the preparation of plastics.

  16. GlidArc-assisted production of synthesis gas from various carbonaceous feedstocks

    International Nuclear Information System (INIS)

    Czernichowski, A.; Czernichowski, P.; Czernichowski, M.

    2003-01-01

    Pure Hydrogen or its mixture with Carbon Monoxide (called Synthesis Gas) will be massively extracted from various fossil or renewable feedstocks. Such matters contain contaminants (principally Sulphur) that make conventional catalytic reforming technologies very difficult to run without a prior deep cleaning of the feeds in order to avoid the reformer's catalyst poisoning. We propose a non-catalytic process in which almost any carbonaceous feed is converted into the Synthesis Gas in a presence of high-voltage discharges (called GlidArc) that assist the exothermic Partial Oxidation POX). The unique oxidant is air. This contribution presents some of our tests with natural gas, cyclohexane, heptane, toluene, various gasolines, and various diesel oils (including logistic ones). In two separate contributions to this Conference we present our more expanded studies on the GlidArc-assisted POX reforming of commercial propane and rapeseed oil (canola). Our reactors (1- or 2-Liter scale) work at atmospheric pressure and need less than 0.5 kW electric power (rather about 0.1 kW) to produce up to 9 m 3 (n)/h of Nitrogen-diluted SynGas containing up to 27% of H 2 and up to 23% of CO. Such assisting power represents roughly less than 5% (rather around 2%) with respect to the Lower Heating Value of produced Synthesis Gas (up to 11 kW). Recycling such relatively small portion of the power is an acceptable compromise. All tested feeds are totally reformed. No soot is observed at a sufficient O/C ratio. (author)

  17. Simulation-Optimization Framework for Synthesis and Design of Natural Gas Downstream Utilization Networks

    Directory of Open Access Journals (Sweden)

    Saad A. Al-Sobhi

    2018-02-01

    Full Text Available Many potential diversification and conversion options are available for utilization of natural gas resources, and several design configurations and technology choices exist for conversion of natural gas to value-added products. Therefore, a detailed mathematical model is desirable for selection of optimal configuration and operating mode among the various options available. In this study, we present a simulation-optimization framework for the optimal selection of economic and environmentally sustainable pathways for natural gas downstream utilization networks by optimizing process design and operational decisions. The main processes (e.g., LNG, GTL, and methanol production, along with different design alternatives in terms of flow-sheeting for each main processing unit (namely syngas preparation, liquefaction, N2 rejection, hydrogen, FT synthesis, methanol synthesis, FT upgrade, and methanol upgrade units, are used for superstructure development. These processes are simulated using ASPEN Plus V7.3 to determine the yields of different processing units under various operating modes. The model has been applied to maximize total profit of the natural gas utilization system with penalties for environmental impact, represented by CO2eq emission obtained using ASPEN Plus for each flowsheet configuration and operating mode options. The performance of the proposed modeling framework is demonstrated using a case study.

  18. Swarm intelligence for multi-objective optimization of synthesis gas production

    Science.gov (United States)

    Ganesan, T.; Vasant, P.; Elamvazuthi, I.; Ku Shaari, Ku Zilati

    2012-11-01

    In the chemical industry, the production of methanol, ammonia, hydrogen and higher hydrocarbons require synthesis gas (or syn gas). The main three syn gas production methods are carbon dioxide reforming (CRM), steam reforming (SRM) and partial-oxidation of methane (POM). In this work, multi-objective (MO) optimization of the combined CRM and POM was carried out. The empirical model and the MO problem formulation for this combined process were obtained from previous works. The central objectives considered in this problem are methane conversion, carbon monoxide selectivity and the hydrogen to carbon monoxide ratio. The MO nature of the problem was tackled using the Normal Boundary Intersection (NBI) method. Two techniques (Gravitational Search Algorithm (GSA) and Particle Swarm Optimization (PSO)) were then applied in conjunction with the NBI method. The performance of the two algorithms and the quality of the solutions were gauged by using two performance metrics. Comparative studies and results analysis were then carried out on the optimization results.

  19. Synthesis of refractory organic matter in the ionized gas phase of the solar nebula.

    Science.gov (United States)

    Kuga, Maïa; Marty, Bernard; Marrocchi, Yves; Tissandier, Laurent

    2015-06-09

    In the nascent solar system, primitive organic matter was a major contributor of volatile elements to planetary bodies, and could have played a key role in the development of the biosphere. However, the origin of primitive organics is poorly understood. Most scenarios advocate cold synthesis in the interstellar medium or in the outer solar system. Here, we report the synthesis of solid organics under ionizing conditions in a plasma setup from gas mixtures (H2(O)-CO-N2-noble gases) reminiscent of the protosolar nebula composition. Ionization of the gas phase was achieved at temperatures up to 1,000 K. Synthesized solid compounds share chemical and structural features with chondritic organics, and noble gases trapped during the experiments reproduce the elemental and isotopic fractionations observed in primitive organics. These results strongly suggest that both the formation of chondritic refractory organics and the trapping of noble gases took place simultaneously in the ionized areas of the protoplanetary disk, via photon- and/or electron-driven reactions and processing. Thus, synthesis of primitive organics might not have required a cold environment and could have occurred anywhere the disk is ionized, including in its warm regions. This scenario also supports N2 photodissociation as the cause of the large nitrogen isotopic range in the solar system.

  20. Fiscal 1998 New Sunshine Project research report. Development of separation technology of hetero-compounds from coal-derived oil, and use methods of them; 1998 nendo sekitan ekikayuchu no tetero kagobutsu nado no bunri gijutsu to yoto no kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This project develops the efficient separation technology of compounds including hetero-atoms such as O and N from coal- derived oil, and researches effective use methods of them. Study is made on the concrete applications and problems of the following separation technologies of hetero-compounds: Distillation/refrigeration, extraction, supercritical gas extraction, pressurized crystallization, crystallization, adsorption, and membrane separation technologies. Based on the study result, the applicability of such various separation technologies of hetero-compounds from coal-derived oil fractions is confirmed experimentally. By using the newly developed bench-scale test equipment of an optimum separation process, the process performance is confirmed, and various engineering data are collected. Study is also made on the effective use method of the hetero-compounds separated by the above equipment. In fiscal 1998, as the electric membrane dialysis experiment result on phenolates derived from phenols in Kashima pilot naphtha and atmospheric light oil, the existence of substances (Ca, Fe, SO{sub 4}) deteriorating membranes was confirmed. Preventive measures against contamination of these bivalent cations and anions are one of future issues. (NEDO)

  1. All-gas-phase synthesis of UiO-66 through modulated atomic layer deposition

    Science.gov (United States)

    Lausund, Kristian Blindheim; Nilsen, Ola

    2016-11-01

    Thin films of stable metal-organic frameworks (MOFs) such as UiO-66 have enormous application potential, for instance in microelectronics. However, all-gas-phase deposition techniques are currently not available for such MOFs. We here report on thin-film deposition of the thermally and chemically stable UiO-66 in an all-gas-phase process by the aid of atomic layer deposition (ALD). Sequential reactions of ZrCl4 and 1,4-benzenedicarboxylic acid produce amorphous organic-inorganic hybrid films that are subsequently crystallized to the UiO-66 structure by treatment in acetic acid vapour. We also introduce a new approach to control the stoichiometry between metal clusters and organic linkers by modulation of the ALD growth with additional acetic acid pulses. An all-gas-phase synthesis technique for UiO-66 could enable implementations in microelectronics that are not compatible with solvothermal synthesis. Since this technique is ALD-based, it could also give enhanced thickness control and the possibility to coat irregular substrates with high aspect ratios.

  2. Process for the manufacture of a gas largely free of inert gases for synthesis. Verfahren zur Herstellung eines weitgehend inertfreien Gases zur Synthese

    Energy Technology Data Exchange (ETDEWEB)

    Eisenlohr, K H; Gaensslen, H; Kriebel, M; Tanz, H

    1983-11-10

    In a process for producing a gas largely free of inert gases for the synthesis of alcohols, particularly methanol, and of hydrocarbons from coal or heavy hydrocarbons by gasification under pressure with oxygen and steam, the crude gas is cooled, the impurities are removed by washing with methanol and the methanol is removed from the cold pure gas by molecular sieves. The pure gas is then cooled further by evaporation and methane is distilled from the liquid part while simultaneously obtaining the synthetic gas consisting of hydrogen and carbon monoxide which is largely free of methane. The methane is wholly or partly compressed and then split into carbon monoxide and hydrogen using steam and oxygen. The split gas is fed back and mixed with the synthesis gas or the partly cleaned crude gas. The synthesis gas heated to the ambient temperature, freed of impurities and free of methane is compressed to the required synthesis pressure.

  3. COAL DERIVED MATRIX PITCHES FOR CARBON-CARBON COMPOSITE MANUFACTURE/PRODUCTION OF FIBERS AND COMPOSITES FROM COAL-BASED PRECURSORS

    Energy Technology Data Exchange (ETDEWEB)

    Peter G. Stansberry; John W. Zondlo

    2001-07-01

    The Consortium for premium Carbon Products from Coal, with funding from the US Department of Energy, National Energy Technology Laboratory continue with the development of innovative technologies that will allow coal or coal-derived feedstocks to be used in the production of value-added carbon materials. In addition to supporting eleven independent projects during budget period 3, three meetings were held at two separate locations for the membership. The first was held at Nemacolin Woodlands Resort on May 15-16, 2000. This was followed by two meetings at Penn State, a tutorial on August 11, 2000 and a technical progress meeting on October 26-27.

  4. Co-pyrolysis of coal with hydrogen-rich gases. 1. Coal pyrolysis under coke-oven gas and synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.; Li, B.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). State Key Lab. of Coal Conversion

    1998-06-01

    To improve the economics of the hydropyrolysis process, it has been suggested that cheaper hydrogen-rich gases (such as coke oven gas, synthesis gas) could be used instead of pure hydrogen. Pyrolysis of Chinese Xianfeng lignite was carried out with coke oven gas (COG) and synthesis gas (SG) as reactive gases at 0.1-5 MPa and at a final temperature up to 650{degree}C with a heating rate of 5-25{degree}C min{sup -1} in a 10 g fixed-bed reactor. The results indicate that it is possible to use COG and SG instead of pure hydrogen in hydropyrolysis, but that the experimental conditions must be adjusted to optimize the yields of the valuable chemicals. 14 refs., 3 figs., 6 tabs.

  5. Rice leaf hydrophobicity and gas films are conferred by a wax synthesis gene (LGF1) and contribute to flood tolerance

    DEFF Research Database (Denmark)

    Kurokawa, Yusuke; Nagai, Keisuke; Hung, Phung Danh

    2018-01-01

    Floods impede gas (O2and CO2) exchange between plants and the environment. A mechanism to enhance plant gas exchange under water comprises gas films on hydrophobic leaves, but the genetic regulation of this mechanism is unknown. We used a rice mutant (dripping wet leaf 7, drp7) which does...... not retain gas films on leaves, and its wild-type (Kinmaze), in gene discovery for this trait. Gene complementation was tested in transgenic lines. Functional properties of leaves as related to gas film retention and underwater photosynthesis were evaluated. Leaf Gas Film 1 (LGF1) was identified as the gene...... determining leaf gas films. LGF1 regulates C30 primary alcohol synthesis, which is necessary for abundant epicuticular wax platelets, leaf hydrophobicity and gas films on submerged leaves. This trait enhanced underwater photosynthesis 8.2-fold and contributes to submergence tolerance. Gene function...

  6. Synthesis of Fe Nanoparticles Functionalized with Oleic Acid Synthesized by Inert Gas Condensation

    Directory of Open Access Journals (Sweden)

    L. G. Silva

    2014-01-01

    Full Text Available In this work, we study the synthesis of monodispersed Fe nanoparticles (Fe-NPs in situ functionalized with oleic acid. The nanoparticles were self-assembled by inert gas condensation (IGC technique by using magnetron-sputtering process. Structural characterization of Fe-NPs was performed by transmission electron microscopy (TEM. Particle size control was carried out through the following parameters: (i condensation zone length, (ii magnetron power, and (iii gas flow (Ar and He. Typically the nanoparticles generated by IGC showed diameters which ranged from ~0.7 to 20 nm. Mass spectroscopy of Fe-NPs in the deposition system allowed the study of in situ nanoparticle formation, through a quadrupole mass filter (QMF that one can use together with a mass filter. When the deposition system works without quadrupole mass filter, the particle diameter distribution is around +/−20%. When the quadrupole is in line, then the distribution can be reduced to around +/−2%.

  7. GlidArc-assisted production of synthesis gas from LPG (Propane)

    International Nuclear Information System (INIS)

    Czernichowski, A.; Czernichowski, P.; Czernichowski, M.

    2003-01-01

    Small and medium size reformers that run on widely available Liquefied Petroleum Gas (LPG, containing mostly the propane) can provide Synthesis Gas (or Hydrogen extracted from it) to some Fuel Cell powered cars, boats, homes, farms etc. reducing therefore costs of the pure Hydrogen distribution. We contribute to such idea realization through our simply, plasma-assisted reformer avoiding a need of poison resistant catalysts or prior LPG desulfurizer. In fact, any level of sulphur in LPG is accepted for our non-catalytic reformer based on high-voltage discharges (called GlidArc). The discharges catalytically assist the exothermic partial oxidation process. Electric power assistance is less than 2% of the Lower Heating Value (LHV) of produced SynGas. Recycling such a small portion of the energy is therefore an acceptable compromise. The unique oxidant source is air. This contribution presents our expanded tests with commercial LPG in a 1-L reactor working at atmospheric pressure. At a 0.1 kW electric power assistance we produce a Nitrogen-diluted SynGas containing up to 45% of H 2 +CO at the output flow rate corresponding up to 2.7 m 3 (n)/h of pure H 2 +CO mixture that is equivalent to LHV output power of 8.6 kW. The LPG is totally reformed at more than 70% energetic efficiency and at the total absence of soot. (author)

  8. Synthesis and application of graphene–silver nanowires composite for ammonia gas sensing

    International Nuclear Information System (INIS)

    Tran, Quang Trung; Huynh, Tran My Hoa; Tong, Duc Tai; Tran, Van Tam; Nguyen, Nang Dinh

    2013-01-01

    Graphene, consisting of a single carbon layer in a two-dimensional (2D) lattice, has been a promising material for application to nanoelectrical devices in recent years. In this study we report the development of a useful ammonia (NH 3 ) gas sensor based on graphene–silver nanowires ‘composite’ with planar electrode structure. The basic strategy involves three steps: (i) preparation of graphene oxide (GO) by modified Hummers method; (ii) synthesis of silver nanowires by polyol method; and (iii) preparation of graphene and silver nanowires on two electrodes using spin and spray-coating of precursor solutions, respectively. Exposure of this sensor to NH 3 induces a reversible resistance change at room temperature that is as large as ΔR/R 0 ∼ 28% and this sensitivity is eight times larger than the sensitivity of the ‘intrinsic’ graphene based NH 3 gas sensor (ΔR/R 0 ∼ 3,5%). Their responses and the recovery times go down to ∼200 and ∼60 s, respectively. Because graphene synthesized by chemical methods has many defects and small sheets, it cannot be perfectly used for gas sensor or for nanoelectrical devices. The silver nanowires are applied to play the role of small bridges connecting many graphene islands together to improve electrical properties of graphene/silver nanowires composite and result in higher NH 3 gas sensitivity. (paper)

  9. Preliminary study of synthesis gas production from water electrolysis, using the ELECTROFUEL® concept

    International Nuclear Information System (INIS)

    Guerra, L.; Gomes, J.; Puna, J.; Rodrigues, J.

    2015-01-01

    This paper describes preliminary work on the generation of synthesis gas from water electrolysis using graphite electrodes without the separation of the generated gases. This is an innovative process, that has no similar work been done earlier. Preliminary tests allowed to establish correlations between the applied current to the electrolyser and flow rate and composition of the generated syngas, as well as a characterisation of generated carbon nanoparticles. The obtained syngas can further be used to produce synthetic liquid fuels, for example, methane, methanol or DME (dimethyl ether) in a catalytic reactor, in further stages of a present ongoing project, using the ELECTROFUEL ® concept. The main competitive advantage of this project lies in the built-in of an innovative technology product, from RE (renewable energy) power in remote locations, for example, islands, villages in mountains as an alternative for energy storage for mobility constraints. - Highlights: • Generation of synthesis gas from water electrolysis without separation of gases. • Obtained syngas: 7.7% CO; 10.3% O 2 and 2.0% CO 2 . • Syngas can further be used to produce synthetic liquid fuels

  10. Single-step gas phase synthesis of stable iron aluminide nanoparticles with soft magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Vernieres, Jerome, E-mail: Jerome.vernieres@oist.jp; Benelmekki, Maria; Kim, Jeong-Hwan; Grammatikopoulos, Panagiotis; Diaz, Rosa E. [Nanoparticles by Design Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, 1919-1 Tancha, Onna Son, Okinawa 904-0495 (Japan); Bobo, Jean-François [Centre d’Elaboration de Materiaux et d’Etudes Structurales (CEMES), 29 rue Jeanne Marvig, 31055 Toulouse Cedex 4 (France); Sowwan, Mukhles, E-mail: Mukhles@oist.jp [Nanoparticles by Design Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, 1919-1 Tancha, Onna Son, Okinawa 904-0495 (Japan); Nanotechnology Research Laboratory, Al-Quds University, P.O. Box 51000, East Jerusalem, Palestine (Country Unknown)

    2014-11-01

    Soft magnetic alloys at the nanoscale level have long generated a vivid interest as candidate materials for technological and biomedical purposes. Consequently, controlling the structure of bimetallic nanoparticles in order to optimize their magnetic properties, such as high magnetization and low coercivity, can significantly boost their potential for related applications. However, traditional synthesis methods stumble upon the long standing challenge of developing true nanoalloys with effective control over morphology and stability against oxidation. Herein, we report on a single-step approach to the gas phase synthesis of soft magnetic bimetallic iron aluminide nanoparticles, using a versatile co-sputter inert gas condensation technique. This method allowed for precise morphological control of the particles; they consisted of an alloy iron aluminide crystalline core (DO{sub 3} phase) and an alumina shell, which reduced inter-particle interactions and also prevented further oxidation and segregation of the bimetallic core. Remarkably, the as-deposited alloy nanoparticles show interesting soft magnetic properties, in that they combine a high saturation magnetization (170 emu/g) and low coercivity (less than 20 Oe) at room temperature. Additional functionality is tenable by modifying the surface of the particles with a polymer, to ensure their good colloidal dispersion in aqueous environments.

  11. Power to Fuels: Dynamic Modeling of a Slurry Bubble Column Reactor in Lab-Scale for Fischer Tropsch Synthesis under Variable Load of Synthesis Gas

    Directory of Open Access Journals (Sweden)

    Siavash Seyednejadian

    2018-03-01

    Full Text Available This research developed a comprehensive computer model for a lab-scale Slurry Bubble Column Reactor (SBCR (0.1 m Dt and 2.5 m height for Fischer–Tropsch (FT synthesis under flexible operation of synthesis gas load flow rates. The variable loads of synthesis gas are set at 3.5, 5, 7.5 m3/h based on laboratory adjustments at three different operating temperatures (483, 493 and 503 K. A set of Partial Differential Equations (PDEs in the form of mass transfer and chemical reaction are successfully coupled to predict the behavior of all the FT components in two phases (gas and liquid over the reactor bed. In the gas phase, a single-bubble-class-diameter (SBCD is adopted and the reduction of superficial gas velocity through the reactor length is incorporated into the model by the overall mass balance. Anderson Schulz Flory distribution is employed for reaction kinetics. The modeling results are in good agreement with experimental data. The results of dynamic modeling show that the steady state condition is attained within 10 min from start-up. Furthermore, they show that step-wise syngas flow rate does not have a detrimental influence on FT product selectivity and the dynamic modeling of the slurry reactor responds quite well to the load change conditions.

  12. Catalytic and Noncatalytic Conversion of Methane to Olefins and Synthesis Gas in an AC Parallel Plate Discharge Reactor

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Khodagholi

    2013-01-01

    Full Text Available Direct conversion of methane to ethylene, acetylene, and synthesis gas at ambient pressure and temperature in a parallel plate discharge reactor was investigated. The experiments were carried out using a quartz reactor of outer diameter of 9 millimeter and a driving force of ac current of 50 Hz. The input power to the reactor to establish a stable gas discharge varied from 9.6 to maximum 15.3 watts (w. The effects of ZSM5, Fe–ZSM5, and Ni–ZSM5 catalysts combined with corona discharge for conversion of methane to more valued products have been addressed. It was found that in presence or absence of a catalyst in gas discharge reactor, the rate of methane and oxygen conversion increased upon higher input power supplied to the reactor. The effect of Fe–ZSM5 catalyst combined with gas discharge plasma yields C2 hydrocarbons up to 21.9%, which is the highest productions of C2 hydrocarbons in this work. The effect of combined Ni–ZSM5 and gas discharge plasma was mainly production of synthesis gas. The advantage of introducing ZSM5 to the plasma zone was increase in synthesis gas and acetylene production. The highest energy efficiency was 0.22 mmol/kJ, which belongs to lower rate of energy injection to the reactor.

  13. Partial catalytic oxidation of CH{sub 4} to synthesis gas for power generation - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mantzaras, I.; Schneider, A.

    2006-03-15

    The partial oxidation of methane to synthesis gas over rhodium catalysts has been investigated experimentally and numerically in the pressure range of 4 to 10 bar. The methane/oxidizer feed has been diluted with large amounts of H{sub 2}O and CO{sub 2} (up to 70% vol.) in order to simulate new power generation cycles with large exhaust gas recycle. Experiments were carried out in an optically accessible channel-flow reactor that facilitated laser-based in situ measurements, and also in a subscale gas-turbine catalytic reactor. Full-elliptic steady and transient two-dimensional numerical codes were used, which included elementary hetero-/homogeneous chemical reaction schemes. The following are the key conclusions: a) Heterogeneous (catalytic) and homogeneous (gas-phase) schemes have been validated for the partial catalytic oxidation of methane with large exhaust gas recycle. b) The impact of added H{sub 2}O and CO{sub 2} has been elucidated. The added H{sub 2}O increased the methane conversion and hydrogen selectivity, while it decreased the CO selectivity. The chemical impact of CO{sub 2} (dry reforming) was minimal. c) The numerical model reproduced the measured catalytic ignition times. It was further shown that the chemical impact of H{sub 2}O and CO{sub 2} on the catalytic ignition delay times was minimal. d) The noble metal dispersion increased with different support materials, in the order Rh/{alpha}-Al{sub 2}O{sub 3}, Rh/ZrO{sub 2}, and Rh/Ce-ZrO{sub 2}. An evident relationship was established between the noble metal dispersion and the catalytic behavior. (authors)

  14. Effects of calcination and activation conditions on ordered mesoporous carbon supported iron catalysts for production of lower olefins from synthesis gas

    NARCIS (Netherlands)

    Oschatz, M; van Deelen, T W; Weber, J L; Lamme, W S; Wang, G; Goderis, B; Verkinderen, O; Dugulan, A I; de Jong, K P

    2016-01-01

    Lower C2–C4 olefins are important commodity chemicals usually produced by steam cracking of naphtha or fluid catalytic cracking of vacuum gas oil. The Fischer–Tropsch synthesis of lower olefins (FTO) with iron-based catalysts uses synthesis gas as an alternative feedstock. Nanostructured carbon

  15. Hydrothermal synthesis of h-MoO3 microrods and their gas sensing properties to ethanol

    International Nuclear Information System (INIS)

    Liu, Yueli; Yang, Shuang; Lu, Yu; Podval’naya, Natal’ya V.; Chen, Wen; Zakharova, Galina S.

    2015-01-01

    Highlights: • A simple hydrothermal acid-free method for the synthesis of h-MoO 3 microrods with the hexagonal cross-section is reported. • The h-MoO 3 phase is transformed to α-MoO 3 at 439 °C. • The h-MoO 3 microrods were employed to fabricate gas sensors to detect ethanol. • Sensor showed highest response with a sensitivity of 8.24–500 ppm C 2 H 5 OH at operating temperature of 332 °C. - Abstract: Hexagonal molybdenum trioxide (h-MoO 3 ) microrods were successfully synthesized via a novel and facile hydrothermal route from peroxomolybdate solution with the presence of NH 4 Cl as the mineralizer. A variety of the techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry combined with the thermal gravimetric analysis (DSC–TG) were used to characterize the product. The gas sensing test indicates that h-MoO 3 microrods have a good response to 5–500 ppm ethanol in the range of 273–380 °C, and the optimum operating temperature is 332 °C with a high sensitivity of 8.24 to 500 ppm ethanol. Moreover, it also has a good selectivity toward ethanol gas if compared with other gases, such as ammonia, methanol and toluene. The sensing mechanism of h-MoO 3 microrods to ethanol was also discussed.

  16. Evaluation of the LMFBR cover gas source term and synthesis of the associated R and D

    International Nuclear Information System (INIS)

    Balard, F.; Carluec, B.

    1996-01-01

    K, Germany), sodium aerosols formation in the cover gas (UK, Japan, France), fuel degassing (Mignanelli synthesis, UK). (author)

  17. Facile synthesis of improved room temperature gas sensing properties of TiO2 nanostructures: Effect of acid treatment

    CSIR Research Space (South Africa)

    Tshabalala, Zamaswazi P

    2016-03-01

    Full Text Available and Actuators B: Chemical Facile synthesis of improved room temperature gas sensing properties of TiO2 nanostructures: Effect of acid treatment Z.P. Tshabalalaa,b, D.E. Motaunga,∗, G.H. Mhlongoa,∗, O.M. Ntwaeaborwab,∗ a DST/CSIR, National Centre...

  18. Ambient temperature aqueous synthesis of ultrasmall copper doped ceria nanocrystals for the water gas shift and carbon monoxide oxidation reactions

    Energy Technology Data Exchange (ETDEWEB)

    Curran, Christopher D. [Department of Chemical and Biomolecular Engineering; Lehigh University; Bethlehem; USA; Lu, Li [Department of Materials Science and Engineering; Lehigh University; Bethlehem; USA; Kiely, Christopher J. [Department of Chemical and Biomolecular Engineering; Lehigh University; Bethlehem; USA; Department of Materials Science and Engineering; McIntosh, Steven [Department of Chemical and Biomolecular Engineering; Lehigh University; Bethlehem; USA

    2018-01-01

    Ultra-small CuxCe1-xO2-δnanocrystals were prepared through a room temperature, aqueous synthesis method, achieving high copper doping and low water gas shift activation energy.

  19. Effect of surface composition of yttrium-stabilized zirconia on partial oxidation of methane to synthesis gas.

    NARCIS (Netherlands)

    Zhu, J.J.; van Ommen, J.G.; Knoester, A.; Lefferts, Leonardus

    2005-01-01

    Catalytic partial oxidation of methane to synthesis gas (CPOM) over yttrium-stabilized zirconia (YSZ) was studied within a wide temperature window (500¿1100 °C). The catalysts were characterized by X-ray fluorescence (XRF) and low-energy ion scattering (LEIS). The influence of calcination

  20. The performance of a thermophilic microbial fuel cell fed with synthesis gas.

    Science.gov (United States)

    Hussain, A; Mehta, P; Raghavan, V; Wang, H; Guiot, S R; Tartakovsky, B

    2012-08-10

    This study demonstrated electricity generation in a thermophilic microbial fuel cell (MFC) operated on synthesis gas (syngas) as the sole electron donor. At 50°C, a volumetric power output of 30-35 mWL(R)(-1) and a syngas conversion efficiency of 87-98% was achieved. The observed pathway of syngas conversion to electricity primarily consisted of a two-step process, where the carbon monoxide and hydrogen were first converted to acetate, which was then consumed by the anodophilic bacteria to produce electricity. A denaturing gradient gel electrophoresis (DGGE) analysis of the 16S rDNA revealed the presence of Geobacter species, Acetobacter, methanogens and several uncultured bacteria and archaea in the anodic chamber. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  1. Synthesis and integration of one-dimensional nanostructures for chemical gas sensing applications

    Science.gov (United States)

    Parthangal, Prahalad Madhavan

    The need for improved measurement technology for the detection and monitoring of gases has increased tremendously for maintenance of domestic and industrial health and safety, environmental surveys, national security, food-processing, medical diagnostics and various other industrial applications. Among the several varieties of gas sensors available in the market, solid-state sensors are the most popular owing to their excellent sensitivity, ruggedness, versatility and low cost. Semiconducting metal oxides such as tin oxide (SnO2), zinc oxide (ZnO), and tungsten oxide (WO3) are routinely employed as active materials in these sensors. Since their performance is directly linked to the exposed surface area of the sensing material, one-dimensional nanostructures possessing very high surface to volume ratios are attractive candidates for designing the next generation of sensors. Such nano-sensors also enable miniaturization thereby reducing power consumption. The key to achieve success in one-dimensional nanotechnologies lies in assembly. While synthesis techniques and capabilities continue to expand rapidly, progress in controlled assembly has been sluggish due to numerous technical challenges. In this doctoral thesis work, synthesis and characterization of various one-dimensional nanostructures including nanotubes of SnO2, and nanowires of WO3 and ZnO, as well as their direct integration into miniature sensor platforms called microhotplates have been demonstrated. The key highlights of this research include devising elegant strategies for growing metal oxide nanotubes using carbon nanotubes as templates, substantially reducing process temperatures to enable growth of WO3 nanowires on microhotplates, and successfully fabricating a ZnO nanowire array based sensor using a hybrid nanowire-nanoparticle assembly approach. In every process, the gas-sensing properties of one-dimensional nanostructures were observed to be far superior in comparison with thin films of the same

  2. Gas-phase laser synthesis of aggregation-free, size-controlled hydroxyapatite nanoparticles

    International Nuclear Information System (INIS)

    Bapat, Parimal V.; Kraft, Rebecca; Camata, Renato P.

    2012-01-01

    Nanophase hydroxyapatite (HA) is finding applications in many areas of biomedical research, including bone tissue engineering, drug delivery, and intracellular imaging. Details in chemical composition, crystal phase makeup, size, and shape of HA nanoparticles play important roles in achieving the favorable biological responses required in these applications. Most of the nanophase HA synthesis techniques involve solution-based methods that exhibit substantial aggregation of particles upon precipitation. Typically these methods also have limited control over the particle size and crystal phase composition. In this study, we describe the gas-phase synthesis of aggregation-free, size-controlled HA nanoparticles with mean size in the 20–70 nm range using laser ablation followed by aerosol electrical mobility classification. Nanoparticle deposits with adjustable number concentration were obtained on solid substrates. Particles were characterized by transmission electron microscopy, atomic force microscopy, and X-ray diffraction. Samples are well represented by log-normal size distributions with geometric standard deviation σ g ≈ 1.2. The most suitable conditions for HA nanoparticle formation at a laser fluence of 5 J/cm 2 were found to be a temperature of 800 °C and a partial pressure of water of 160 mbar.

  3. Controlled gas-liquid interfacial plasmas for synthesis of nano-bio-carbon conjugate materials

    Science.gov (United States)

    Kaneko, Toshiro; Hatakeyama, Rikizo

    2018-01-01

    Plasmas generated in contact with a liquid have been recognized to be a novel reactive field in nano-bio-carbon conjugate creation because several new chemical reactions have been yielded at the gas-liquid interface, which were induced by the physical dynamics of non-equilibrium plasmas. One is the ion irradiation to a liquid, which caused the spatially selective dissociation of the liquid and the generation of additive reducing and oxidizing agents, resulting in the spatially controlled synthesis of nanostructures. The other is the electron irradiation to a liquid, which directly enhanced the reduction action at the plasma-liquid interface, resulting in temporally controlled nanomaterial synthesis. Using this novel reaction field, gold nanoparticles with controlled interparticle distance were synthesized using carbon nanotubes as a template. Furthermore, nanoparticle-biomolecule conjugates and nanocarbon-biomolecule conjugates were successfully synthesized by an aqueous-solution contact plasma and an electrolyte plasma, respectively, which were rapid and low-damage processes suitable for nano-bio-carbon conjugate materials.

  4. Niobium carbide synthesis by solid-gas reaction using a rotating cylinder reactor

    International Nuclear Information System (INIS)

    Fontes, F.A.O.; Gomes, K.K.P.; Oliveira, S.A.; Souza, C.P.; Sousa, J.F.; Rio Grande do Norte Univ., Natal, RN

    2004-01-01

    A rotating cylinder reactor was designed for the synthesis of niobium carbide powders at 1173 K. Niobium carbide, NbC, was prepared by carbothermal reduction starting from commercial niobium pentoxide powders. The reactor was heated using a custom-made, two-part, hinged, electric furnace with programmable temperature control. The design and operational details of the reactor are presented. The longitudinal temperature gradient inside the reactor was determined. Total reaction time was monitored by a gas chromatograph equipped with an FID detector for determination of methane concentrations. The results show that time of reaction depended on rotation speed. NbC was also prepared in a static-bed alumina reactor using the same conditions as in the previous case. The niobium carbide powders were characterized by X-ray diffraction and compared with commercially available products. Morphological, particle size distribution and surface area analyses were obtained using SEM, LDPS and BET, respectively. Therefore, the present study offers a significant technological contribution to the synthesis of NbC powders in a rotating cylinder reactor. (author)

  5. Study on supported binary sulfide catalysts for secondary hydrogenation of coal-derived liquids; Sekitan ekikayu niji suisoka shokubai no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, H.; Matsubayashi, N.; Sato, T.; Imamura, M.; Yoshimura, Y.; Nishijima, A. [National Institute of Materials and Chemical Research, Tsukuba (Japan)

    1995-07-28

    To utilize the high performance of supported catalysts in coal liquefaction processes, one of the promising ways is to apply hydroprocessing sulfide catalysts to the secondary hydrogenation of coal-derived liquids which have undergone the solid separation unit. However, when the product yield from the first-stage liquefaction is maximized, the feed stocks in the secondary hydrogenation contain large amounts of residual fractions with preasphaltenes and metallic components. In this case, the development of a long-life catalyst is essential to establish the two-stage process as a practical one. From this viewpoint, the authors have investigated the deactivation causes of supported Ni-Mo sulfide catalysts through the analysis of the used catalysts in the secondary hydrogenation of coal-derived liquids for long periods. The major cause of the catalyst deactivation has been found to be metallic and carbonaceous deposition on the catalyst, which results thin layer which covers the catalyst particles. The catalysts located at the reactor inlet are more rapidly deactivated than those at the rector exit because of larger amounts of metallic foul ants and the above described shell-like layer. Hydrocracking active sites are much heavily deactivated compared with hydrogenation active sites. It is inferred that the basic or polar compounds contained in coal liquids are permanency adsorbed on the hydrocracking active sites. Spectroscopic analysis of the used catalysts clarified the destruction of the active phase of the binary sulfides, through the segregation and crystal growth. The structural changes of the catalysts are very likely caused by heteroatom compounds in the preasphaltenes. Thus, the primary cause of the catalyst deactivation is the preasphaltenes in the coal liquids. Hydroaromatic compounds in the coal liquids suppress the change of the deposited carbonaceous materials into inert coke which permanently deactivate the catalyst.

  6. Hydrogen enrichment and separation from synthesis gas by the use of a membrane reactor

    International Nuclear Information System (INIS)

    Sanchez, J.M.; Barreiro, M.M.; Marono, M.

    2011-01-01

    One of the objectives of the CHRISGAS project was to study innovative gas separation and gas upgrading systems that have not been developed sufficiently yet to be tested at a demonstration scale within the time frame of the project, but which show some attractive merits and features for further development. In this framework CIEMAT studied, at bench scale, hydrogen enrichment and separation from syngas by the use of membranes and membrane catalytic reactors. In this paper results about hydrogen separation from synthesis gas by means of selective membranes are presented. Studies dealt with the evaluation of permeation and selectivity to hydrogen of prepared and pre-commercial Pd-based membranes. Whereas prepared membranes turned out to be non-selective, due to discontinuities of the palladium layer, studies conducted with the pre-commercial membrane showed that by means of a membrane reactor it is possible to completely separate hydrogen from the other gas components and produce pure hydrogen as a permeate stream, even in the case of complex reaction system (H 2 /CO/CO 2 /H 2 O) under WGS conditions gas mixtures. The advantages of using a water-gas shift membrane reactor (MR) over a traditional fixed bed reactor (TR) have also been studied. The experimental device included the pre-commercial Pd-based membrane and a commercial high temperature Fe-Cr-based, WGS catalyst, which was packed in the annulus between the membrane and the reactor outer shell. Results show that in the MR concept, removal of H 2 from the reaction side has a positive effect on WGS reaction, reaching higher CO conversion than in a traditional packed bed reactor at a given temperature. On increasing pressure on the reaction side permeation is enhanced and hence carbon monoxide conversion increases. -- Highlights: → H 2 enrichment and separation using a bench-scale membrane reactor MR is studied. → Permeation and selectivity to H 2 of Pd-based membranes was determined. → Complete separation

  7. Synthesis and Characterization of Quaternary Metal Chalcogenide Aerogels for Gas Separation and Volatile Hydrocarbon Adsorption

    KAUST Repository

    Edhaim, Fatimah A.

    2017-11-01

    In this dissertation, the metathesis route of metal chalcogenide aerogel synthesis was expanded by conducting systematic studies between polysulfide building blocks and the 1st-row transition metal linkers. Resulting materials were screened as sorbents for selective gas separation and volatile organic compounds adsorption. They showed preferential adsorption of polarizable gases (CO2) and organic compounds (toluene). Ion exchange and heavy metal remediation properties have also been demonstrated. The effect of the presence of different counter-ion within chalcogel frameworks on the adsorption capacity of the chalcogels was studied on AFe3Zn3S17 (A= K, Na, and Rb) chalcogels. The highest adsorption capacity toward hydrocarbons and gases was observed on Rb based chalcogels. Adopting a new building block [BiTe3]3- with the 1st-row transition metal ions results in the formation of three high BET surface area chalcogels, KCrBiTe3, KZnBiTe3, and KFeBiTe3. The resulting chalcogels showed preferential adsorption of toluene vapor, and remarkable selectivity of CO2, indicating the potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes. The synthesis and characterization of the rare earth chalcogels NaYSnS4, NaGdSnS4, and NaTbSnS4 are also reported. Rare earth metal ions react with the thiostannate clusters in formamide solution forming extended polymeric networks by gelation. Obtained chalcogels have high BET surface areas, and showed notable adsorption capacity toward CO2 and toluene vapor. These chalcogels have also been engaged in the absorption of different organic molecules. The results reveal the ability of the chalcogels to distinguish among organic molecules on their electronic structures; hence, they could be used as sensors. Furthermore, the synthesis of metal chalcogenide aerogels Co0.5Sb0.33MoS4 and Co0.5Y0.33MoS4 by the sol-gel method is reported. In this system, the building blocks [MoS4]2- chelated with Co2+ and (Sb3

  8. An alternative gas sensor material: Synthesis and electrical characterization of SmCoO3

    International Nuclear Information System (INIS)

    Michel, Carlos Rafael; Delgado, Emilio; Santillan, Gloria; Martinez, Alma H.; Chavez-Chavez, Arturo

    2007-01-01

    Single-phase perovskite SmCoO 3 was prepared by a wet-chemical synthesis technique using metal-nitrates and citric acid; after its characterization by thermal analyses and X-ray diffraction, sintering at 900 deg. C in air, gave single phase and well crystallized powders. The powders were mixed with an organic solvent to prepare a slurry, which was deposited on alumina substrates as thick films, using the screen-printing technique. Electrical and gas sensing properties of sintered SmCoO 3 films were investigated in air, O 2 and CO 2 , the results show that sensitivity reached a maximum value at 420 deg. C, for both gases. Dynamic tests revealed a better behavior of SmCoO 3 in CO 2 than O 2 , due to a fast response and a larger electrical resistance change to this gas. X-ray diffraction made on powders after electrical characterization in gases, showed that perovskite-type structure was preserved

  9. Economic evaluation of the solar thermal co-production of zinc, synthesis gas, and hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Steinfeld, A [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Spiewak, I [EC Joint Research Centre (Spain)

    1999-08-01

    The use of concentrated solar energy for co-producing Zn and synthesis gas from Zn O and natural gas upgrades the calorific value of the initial reactants by 39% and, when compared to the traditional carbothermic reduction of Zn O, has the potential of reducing CO{sub 2} emissions by up to 78%. An economic assessment for an industrial thermochemical plant, 30 to 51 MW solar input, indicates that the cost of solar production of zinc ranges between 89-133 $/t (excluding the cost of Zn O feed and credit for pollution abatement), and thus might be competitive with conventional fossil-fuel-based processes at current fuel prices. The cost of solar H{sub 2}, produced by splitting water with zinc, is estimated to be in the range 0.10-0.14 $/kWh, and it is a favorable long term prospect once the cost of energy will account for the environmental externalities from fossil fuel burning such as the costs for CO{sub 2} mitigation and pollution abatement. (author) 1 fig., 2 tabs., 5 refs.

  10. CdSe Nanoparticles with Clean Surfaces: Gas Phase Synthesis and Optical Properties

    Directory of Open Access Journals (Sweden)

    Zhang Hongwei

    2015-01-01

    Full Text Available CdSe nanoparticles (NPs were generated in gas phase with a magnetron plasma gas aggregation cluster beam source. Coagulation-free CdSe nanocrystals with very clean particle surface and interface, as well as a fairly uniform spatial distribution were obtained. The deposited NPs have a good dispersity with a mean diameter of about 4.8nm. A strong photoluminescence band corresponding to the near- band-edge transition of the CdSe NPs was observed. The CdSe NP films show a significant photoconductance induced by laser irradiation. With an applied bias voltage of 10V, the photo- induced current can be as high as 0.4mA under 0.01mW/mm2 405nm laser illumination. Our approach offers an alternative method for CdSe NP synthesis, which has the advantages such as high purity, good process and product control, as well as mass production, as compared to the existing methods.

  11. Synthesis and gas-sensing characteristics of α-Fe2O3 hollow balls

    Directory of Open Access Journals (Sweden)

    Chu Manh Hung

    2016-03-01

    Full Text Available The synthesis of porous metal-oxide semiconductors for gas-sensing application is attracting increased interest. In this study, α-Fe2O3 hollow balls were synthesized using an inexpensive, scalable, and template-free hydrothermal method. The gas-sensing characteristics of the semiconductors were systematically investigated. Material characterization by XRD, SEM, HRTEM, and EDS reveals that single-phase α-Fe2O3 hollow balls with an average diameter of 1.5 μm were obtained. The hollow balls were formed by self assembly of α-Fe2O3 nanoparticles with an average diameter of 100 nm. The hollow structure and nanopores between the nanoparticles resulted in the significantly high response of the α-Fe2O3 hollow balls to ethanol at working temperatures ranging from 250 °C to 450 °C. The sensor also showed good selectivity over other gases, such as CO and NH3 promising significant application.

  12. Synthesis, characterization and liquefied petroleum gas (LPG) sensing properties of WO3 nano-particles

    Science.gov (United States)

    Singh, Subhash; Majumder, S. B.

    2018-05-01

    Metal oxide sensors, such as ZnO, SnO2, and WO3 etc. have been utilized for several decades for low-costd etection of combustible and toxic gases. In the present work tungsten oxide (WO3) nanoparticles have been prepared by using an economic wet chemical synthesis route. To understand the phase formation behavior of the synthesized powders, X-ray diffraction analysis has been performed. The microstructure evolution of the synthesized powders was characterized by field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The calcined phase pure WO3 nanoparticles are investigated in terms of LPG gas sensing properties. The gas sensing measurements has been done in two different mode of operation (namely static and dynamic measurements). The degree of oxygen deficiency in the WO3 sensor also affected the sensor properties and the optimum oxygen content of WO3 was necessary to get high sensitivity for LPG. The WO3 sensor shows the excellent sensor properties for LPG at the operating temperature of 250°C.

  13. Direct synthesis of iso-butane from synthesis gas or CO2 over CuZnZrAl/Pd-β hybrid catalyst

    Directory of Open Access Journals (Sweden)

    Congming Li

    2017-12-01

    Full Text Available The effect of various factors on the catalytic performance of iso-butane formation over CuZnZrAl/Pd-β hybrid catalyst via synthesis gas or CO2 hydrogenation has been deeply investigated in this work. It was interesting to note that the iso-butane/n-butane ratio value was much higher than that of thermodynamic equilibrium (about 1/1, whose value was directly related to the reaction condition using this hybrid catalyst. In order to further clearly clarify this finding, various experimental reaction factors were selected to investigate the formation of iso-butane. The results revealed that increasing temperature, H2/COx, CO2/COx, and/or Pd loading possessed an inhibiting effect on the iso-butane yield. High selectivity of iso-butane could be achieved by increasing the reaction pressure, W/F and the weight ratio of CuZnZrAl methanol catalyst to Pd-β catalyst. It is also noted that the addition of water seriously suppressed the reaction activity, resulting in the low ratio of iso-butane/n-butane. A possible reaction route was elucidated based on the latest results. This might shed light on the development of a high efficient catalyst for iso-butane production from synthesis gas or CO2 hydrogenation. Keywords: Iso-butane, Synthesis gas, CO2, CuZnZrAl/Pd-β hybrid catalyst

  14. Effects of coal-derived trace species on the performance of molten carbonate fuel cells. Topical report on thermochemical studies

    Energy Technology Data Exchange (ETDEWEB)

    Pigeaud, A.

    1991-10-01

    The overall objective of the present study was to determine in detail the interaction effects of 10 simultaneously present, coal-gas contaminants, both on each other and on components of the Carbonate Fuel Cell. The primary goal was to assess underlying chemistries and reaction mechanisms which may cause decay in fuel cell performance or endurance as a result of both physics-chemical and/or mechanical interactions with the cell components and internal fuel cell parts. It was found, both from theory and cell test evidence, that trace contaminant interactions may occur with: Fuel-cell Electrodes (e.g., in this study with the Ni-anode), Lithium/Potassium Carbonate Electrolyte, Nickel and SS-Hardware, and by Mechanical Obstruction of Gas Flow in the Anode Plenum.

  15. Synthesis Gas Purification Purification des gaz de synthèse

    Directory of Open Access Journals (Sweden)

    Chiche D.

    2013-10-01

    Full Text Available Fischer-Tropsch (FT based B-XTL processes are attractive alternatives for future energy production. These processes aim at converting lignocellulosic biomass possibly in co-processing with petcoke, coal, or vacuum residues into synthetic biofuels. A gasification step converts the feed into a synthesis gas (CO and H2 mixture , which undergoes the Fischer-Tropsch reaction after H2/CO ratio adjustment and CO2 removal. However synthesis gas also contains various impurities that must be removed in order to prevent Fischer-Tropsch catalyst poisoning. Due to the large feedstocks variety that can be processed, significant variations of the composition of the synthesis gas are expected. Especially, this affects the nature of the impurities that are present (element, speciation, as well as their relative contents. Moreover, due to high FT catalyst sensitivity, severe syngas specifications regarding its purity are required. For these reasons, synthesis gas purification constitutes a major challenge for the development of B-XTL processes. In this article, we focus on these major hurdles that have to be overcome. The different kinds of syngas impurities are presented. The influence of the nature of feedstocks, gasification technology and operating conditions on the type and content of impurities is discussed. Highlight is given on the fate of sulfur compounds, nitrogen compounds, halides, transition and heavy metals. Main synthesis gas purification technologies (based on adsorption, absorption, catalytic reactions, etc. are finally described, as well as the related challenges. Les procédés de synthèse de biocarburants par voie Fischer-Tropsch (FT, voies B-XTL, représentent des alternatives prometteuses pour la production d’énergie. Ces procédés permettent la conversion en carburants de synthèse de biomasse lignocellulosique, éventuellement mise en oeuvre en mélange avec des charges fossiles telles que petcoke, charbons ou résidus sous vide. Pour

  16. Flash pyrolysis at high temperature of ligno-cellulosic biomass and its components - production of synthesis gas

    International Nuclear Information System (INIS)

    Couhert, C.

    2007-11-01

    Pyrolysis is the first stage of any thermal treatment of biomass and governs the formation of synthesis gas for the production of electricity, hydrogen or liquid fuels. The objective of this work is to establish a link between the composition of a biomass and its pyrolysis gas. We study experimental flash pyrolysis and fix the conditions in which quantities of gas are maximal, while aiming at a regime without heat and mass transfer limitations (particles about 100 μm): temperature of 950 C and residence time of about 2 s. Then we try to predict gas yields of any biomass according to its composition, applicable in this situation where thermodynamic equilibrium is not reached. We show that an additivity law does not allow correlating gas yields of a biomass with fractions of cellulose, hemi-cellulose and lignin contained in this biomass. Several explanations are suggested and examined: difference of pyrolytic behaviour of the same compound according to the biomass from which it is extracted, interactions between compounds and influence of mineral matter. With the aim of industrial application, we study pyrolysis of millimetric and centimetric size particles, and make a numerical simulation of the reactions of pyrolysis gases reforming. This simulation shows that the choice of biomass affects the quantities of synthesis gas obtained. (author)

  17. Practical experiences with the synthesis of [11C]CH3I through gas phase iodination reaction using a TRACERlabFXC synthesis module

    International Nuclear Information System (INIS)

    Kniess, Torsten; Rode, Katrin; Wuest, Frank

    2008-01-01

    The results of [ 11 C]CH 3 I synthesis through hydrogen gas reduction of [ 11 C]CO 2 on different nickel catalysts (HARSHAW-nickel, SHIMALITE-nickel, nickel on silica/alumina, nickel nanosize 99.99%) followed by gas phase iodination using a TRACERlab FX C synthesis unit are reported. Further reaction parameters such as furnace temperatures, flow rate of hydrogen gas and reduction time were optimized. It was found that reduction of [ 11 C]CO 2 proceeded in 28-83% yield depending on the nickel catalyst and temperature. The gas phase iodination (methane conversion) gave 31-62% of [ 11 C]CH 3 I depending on temperature and amount of iodine in the iodine furnace. [ 11 C]CH 3 I was used for heteroatom methylation reactions exemplified by a piperazine and a phenol (1 and 3). The specific activity of the 11 C-labelled products 2 and 4 was determined after HPLC purification and solid-phase extraction. Compounds 2 and 4 were obtained in 8-14% radiochemical yield (decay-corrected, based upon trapped [ 11 C]CH 4 ) within 30 min. The specific activity was determined to be in the range of 20-30 GBq/μmol at the end-of-synthesis. Nickel catalyst nanosize was found to be superior compared with other Ni catalysts tested. The relatively low specific activity may be mainly due to carbon contaminations originating from the long copper tubing (500 m) between the cyclotron and the radiochemistry facility

  18. Design, Synthesis, and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals. Technical Progress Report

    International Nuclear Information System (INIS)

    Akio Ishikawa; Manuel Ojeda; Nan Yao; Enrique Iglesia

    2006-01-01

    This project extends previously discovered Fe-based catalysts to hydrogen-poor synthesis gas streams derived from coal and biomass sources. These catalysts have shown unprecedented Fischer-Tropsch synthesis rate, selectivity for feedstocks consisting of synthesis gas derived from methane. During the first reporting period, we certified a microreactor, installed required analytical equipment, and reproduced synthetic protocols and catalytic results previously reported. During the second reporting period, we prepared several Fe-based compositions for Fischer-Tropsch synthesis and tested the effects of product recycle under both subcritical and supercritical conditions. During the third and fourth reporting periods, we improved the catalysts preparation method, which led to Fe-based FT catalysts with the highest FTS reaction rates and selectivities so far reported, a finding that allowed their operation at lower temperatures and pressures with high selectivity to desired products (C 5+ , olefins). During this fifth reporting period, we have studied the effects of different promoters on catalytic performance, specifically how their sequence of addition dramatically influences the performance of these materials in the Fischer-Tropsch synthesis. The resulting procedures have been optimized to improve further upon the already unprecedented rates and C 5+ selectivities of the Fe-based catalysts that we have developed as part of this project. During this fifth reporting period, we have also continued our studies of optimal activation procedures, involving reduction and carburization of oxide precursors during the early stages of contact with synthesis gas. We have completed the analysis of the evolution of oxide, carbide, and metal phases of the active iron components during initial contact with synthesis gas using advanced synchrotron techniques based on X-ray absorption spectroscopy. We have confirmed that the Cu or Ru compensates for inhibitory effects of Zn, a surface

  19. One-step synthesis of dimethyl ether from the gas mixture containing CO2 with high space velocity

    International Nuclear Information System (INIS)

    Chen, Wei-Hsin; Lin, Bo-Jhih; Lee, How-Ming; Huang, Men-Han

    2012-01-01

    Highlights: ► A bifunctional catalyst for DME synthesis is prepared using a coprecipitation method. ► The DME synthesis from syngas at a high space velocity of is investigated. ► The reaction is dominated by chemical kinetics at lower reaction temperatures. ► Thermodynamic equilibrium governs the reaction at higher temperatures. ► 0.2 g of ZSM5 is sufficient to be blended with 1 g of the catalyst for DME synthesis. -- Abstract: Dimethyl ether (DME) has been considered as a potential hydrogen carrier used in fuel cells; it can also be consumed as a diesel substitute or chemicals. To develop the technique of DME synthesis, a bifunctional Cu–ZnO–Al 2 O 3 /ZSM5 catalyst is prepared using a coprecipitation method. The reaction characteristics of DME synthesis from syngas at a high space velocity of 15,000 mL (g cat h) −1 are investigated and the effects of reaction temperature, pressure, CO 2 concentration and ZSM5 amount on the synthesis are taken into account. The results suggest that an increase in CO 2 concentration in the feed gas substantially decreases the DME formation. The optimum reaction temperature always occurs at 225 °C, regardless of what the pressure is. It is thus recognized that the DME synthesis is governed by two different mechanisms when the reaction temperature varies. At lower reaction temperatures ( 225 °C). For the CO 2 content of 5 vol.% and the pressure of 40 atm, the maximum DME yield is 1.89 g (g cat h) −1 . It is also found that 0.2 g of ZSM5 is sufficient to be blended with 1 g of the catalyst for DME synthesis.

  20. Thermodynamic-Controlled Gas Phase Process for the Synthesis of Nickel Nanoparticles of Adjustable Size and Morphology

    International Nuclear Information System (INIS)

    Kauffeldt, Elena; Kauffeldt, Thomas

    2006-01-01

    Gas phase processes are a successful route for the synthesis of nano materials. Nickel particles are used in applications ranging from catalysis to nano electronics and energy storage. The application field defines the required particle size, morphology, crystallinity and purity. Nickel tetracarbonyl is the most promising precursor for the synthesis of high purity nickel particles. Due to the toxicity of this precursor and to obtain an optimal process control we developed a two-step flow type process. Nickel carbonyl and nickel particles are synthesized in a sequence of reactions. The particles are formed in a hot wall reactor at temperatures below 400 deg. C in different gas compositions. Varying the process conditions enables the adjustment of the particle size in a range from 3 to 140 nm. The controllable crystalline habits are polycrystalline, single crystals or multiple twinned particles (MTP). Spectroscopic investigations show an excellent purity. We report about the process and first investigations of the properties of the synthesized nickel nanomaterial

  1. Activity and selectivity regulation of synthesis gas reaction over supported ruthenium catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, K; Nobusawa, T; Fukushima, T; Tominaga, H

    1985-01-01

    The catalytic activities of supported ruthenium for synthesis-gas conversion to hydrocarbons was found to be in the following order: TiOS > Nb2O3 > ZrO2 > SiO2 > Ta2O5 > Al2O3 > V2O5 > MoO3 > WO3 > MnO2 > ZnO. Turnover frequencies of the supported ruthenium increased with decrease in dispersion of the metal particles for every carrier material. Even the activities per unit weight of metals were higher for low-dispersion ruthenium of Al2O3, TiO2, and ZrO2. The chain-growth probability of a hydrocarbon product, which is characterized by the Schulz-Flory distribution, increased markedly with decrease in the metal dispersion irrespective of the carrier material. The catalytic activity of ruthenium particles with a dispersed ruthenium increased almost linearly with an increase in reaction pressure (up to at least 2.0 MPa). 23 references, 10 figures, 3 tables.

  2. Selective conversion of synthesis gas into C2-oxygenated products using mixed-metal homogeneous catalysts

    International Nuclear Information System (INIS)

    Whyman, R.

    1986-01-01

    A feature which is a key to any wider utilization of chemistry based on synthesis gas is an understanding of, and more particularly, an ability to control, those factors which determine the selectivity of the C 1 to C 2 transformation during the hydrogenation of carbon monoxide. With the exception of the rhodium-catalyzed conversion of carbon monoxide and hydrogen into ethylene glycol and methanol, in which molar ethylene glycol/methanol selectivities of ca 2/1 may be achieved, other catalyst systems containing metals such as cobalt or ruthenium exhibit only poor selectivities to ethylene glycol. The initial studies in this area were based on the reasoning that, since the reduction of carbon monoxide to C 2 products is a complex, multi-step process, the use of appropriate combinations of metals could generate synergistic effects which might prove more effective (in terms of both catalytic activity and selectivity) than simply the sum of the individual metal components. In particular, the concept of the combination of a good hydrogenation catalyst with a good carbonylation, or ''CO insertion'', catalyst seemed particularly germane. As a result of this approach the authors discovered an unprecedented example of the effect of catalyst promoters, particularly in the enhancement of C 2 /C 1 selectivity, and one which has led to the development of composite mixed-metal homogeneous catalyst systems for the conversion of CO/H 2 into C 2 -oxygenate esters

  3. Hydrothermal synthesis of highly nitrogen-doped few-layer graphene via solid–gas reaction

    International Nuclear Information System (INIS)

    Liang, Xianqing; Zhong, Jun; Shi, Yalin; Guo, Jin; Huang, Guolong; Hong, Caihao; Zhao, Yidong

    2015-01-01

    Highlights: • A novel approach to synthesis of N-doped few-layer graphene has been developed. • The high doping levels of N in products are achieved. • XPS and XANES results reveal a thermal transformation of N bonding configurations. • The developed method is cost-effective and eco-friendly. - Abstract: Nitrogen-doped (N-doped) graphene sheets with high doping concentration were facilely synthesized through solid–gas reaction of graphene oxide (GO) with ammonia vapor in a self-designed hydrothermal system. The morphology, surface chemistry and electronic structure of N-doped graphene sheets were investigated by TEM, AFM, XRD, XPS, XANES and Raman characterizations. Upon hydrothermal treatment, up to 13.22 at% of nitrogen could be introduced into the crumpled few-layer graphene sheets. Both XPS and XANES analysis reveal that the reaction between oxygen functional groups in GO and ammonia vapor produces amide and amine species in hydrothermally treated GO (HTGO). Subsequent thermal annealing of the resultant HTGO introduces a gradual transformation of nitrogen bonding configurations in graphene sheets from amine N to pyridinic and graphitic N with the increase of annealing temperature. This study provides a simple but cost-effective and eco-friendly method to prepare N-doped graphene materials in large-scale for potential applications

  4. Combined synthesis and in situ coating of nanoparticles in the gas phase

    International Nuclear Information System (INIS)

    Laehde, Anna; Raula, Janne; Kauppinen, Esko I.

    2008-01-01

    Combined gas phase synthesis and coating of sodium chloride (NaCl) and lactose nanoparticles has been developed using an aerosol flow reactor. Nano-sized core particles were produced by the droplet-to-particle method and coated in situ by the physical vapour deposition of L-leucine vapour. The saturation of L-leucine in the reactor determined the resulting particle size and size distribution. In general, particle size increased with the addition of L-leucine and notable narrowing of the core particle size distribution was observed. In addition, homogeneous nucleation of the vapour, i.e. formation of pure L-leucine particles, was observed depending on the saturation conditions of L-leucine as well as the core particle characteristics. The effects of core particle properties, i.e. size and solid-state characteristics, on the coating process were studied by comparing the results for coated NaCl and lactose particles. During deposition, L-leucine formed a uniform coating on the surface of the core particles. The coating stabilised the nanoparticles and prevented the sintering of particles during storage.

  5. Deuterium concentration deterioration in feed synthesis gas from ammonia plant to heavy water plant (Preprint No. ED-5)

    International Nuclear Information System (INIS)

    Sah, A.K.

    1989-04-01

    Heavy Water Plant (Thal) is designed for 110 T/ Year capacity (55 T/Year each stream), with inlet deuterium concentration of feed synthesis gas at 115 ppm and depleted to 15 ppm. During first start up of plant the inlet concentration to feed synthesis gas was about 97 ppm. At that time the rich condensate recirculation was not there. To make the effective recirculation of deuterium rich condensate and minimum posssible losses some modifications were carried out in ammonia plant. Major ones are: (i)Demineralised (DM) water export for heavy water plant and urea plant which was having deuterium rich DM water connection was connected with DM water of urea plant which is not rich in deuterium, (ii)Sample cooler pump suction was connected with raw water, (iii)Ammonia plant line No.II condensate stripper was rectified during annual shut down to avoid excessive steam venting from its top and other draining, and (iv)Stripper condensate directly connected to make up water bypassing open settler to avoid evaporation and diffusion losses. With these modifications the deuterium concentration in feed synthesis gas improved to about 105 ppm. To improve it to 115 ppm, further modifications are suggested. (author). 5 figs

  6. Effect of process distillation on mutagenicity and cell-transformation activity of solvent-refined, coal-derived liquids

    Energy Technology Data Exchange (ETDEWEB)

    Pelroy, R.A.; Frazier, M.E.; Later, D.W.; Wright, C.W.; Wilson, B.W.

    1985-05-01

    Blended SRC-II process streams, representing a full boiling range distillate material, were fractionally distilled into non-overlapping 50 F cuts with bp between 300 and 850 C and another set with bp ranging between 138 and 1055 F. Distillate cuts were assayed for mutagenic activity using the histidine reversion assay with Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537, as well as for mammalian-cell transformation (mct) activity in the Syrian hamster embryo test, and DNA damage in the prophage induction assay (pia). Samples were also separated into chemical class fractions by alumina column chromatography and analysed by high resolution gas chromatography. In the met and microbial mutagenicity assays, significant activity was found almost exclusively in cuts with bp> above 700 F, with the highest activity in the mct assay observed for cuts above 800 F. All of the cuts showed increased levels of DNA damage as expressed by lambda pia in Escherichia coli 8177. However, the greatest activity was associated with cuts with bp in the 800 F+ range. Chemical analysis of the 50 F cuts showed a variety of polycyclic aromatic hydrocarbons (PAH) and amino-PAH compounds to be present in the cuts with bp> above 700 F and essentially absent from cuts with bp< 700 F. The sample set of non-overlapping (50 F) cuts were reblended according to the proportions of each cut found in the original blend material. These reblended composites were then assayed to compare their activity with that predicted from the activities of the component cuts. The results indicated the microbial mutagenicity response was essentially additive. Met activities were non-additive, indicating a compositional effect on the expression of transforming agents in the complex mixture. 18 references.

  7. Investigation of sulfur-tolerant catalysts for selective synthesis of hydrocarbon liquids from coal-derived gases. Annual technical progress report, September 19, 1980-September 18, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomew, C.H.

    1981-10-31

    During the past contract year, considerable progress was made in characterization and activity/selectivity testing of iron and cobalt catalysts. Preparation of boride promoted cobalt and iron catalysts was refined and nearly completed. H/sub 2/ and CO adsorption and oxygen titration measurements were performed on a number of supported and unsupported catalysts, especially several boride promoted cobalt and iron catalysts. Activity/selectivity tests of 3 and 15% Fe/SiO/sub 2/ and Co/SiO/sub 2/ and of 6 borided cobalt and iron catalysts were completed. The product distributions for iron and cobalt boride catalysts are unusual and interesting. Boron promoted iron is more active and stable than iron/silica; cobalt boride has an unusually high selectivity for alcohols. Tests to determine effects of H/sub 2/S poisoning on activity/selectivity properties of 15% Co/SiO/sub 2/ indicate that a significant loss of activity occurs over a period of 24 to 28 h in the presence of 10 to 20 ppM H/sub 2/S. Product selectivity to liquids increased through a maximum during the gradual addition of sulfur. Reactant CO and H/sub 2/S interact partially to form COS which is less toxic than H/sub 2/S. H/sub 2/ and CO adsorption data were obtained for 3, 6 and 9% Co/ZSM-5 catalysts prepared and reactor tested by PETC. The unusual and interesting results suggest that metal-support interactions may have an important influence on reactant adsorption properties.

  8. Status and future opportunities for conversion of synthesis gas to liquid energy fuels: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mills, G. (Delaware Univ., Newark, DE (United States). Center for Catalytic Science and Technology)

    1993-05-01

    The manufacture of liquid energy fuels from syngas (a mixture of H[sub 2] and CO, usually containing CO[sub 2]) is of growing importance and enormous potential because: (1) Abundant US supplies of coal, gas, and biomass can be used to provide the needed syngas. (2) The liquid fuels produced, oxygenates or hydrocarbons, can help lessen environmental pollution. Indeed, oxygenates are required to a significant extent by the Clean Air Act Amendments (CAAA) of 1990. (3) Such liquid synfuels make possible high engine efficiencies because they have high octane or cetane ratings. (4) There is new, significantly improved technology for converting syngas to liquid fuels and promising opportunities for further improvements. This is the subject of this report. The purpose of this report is to provide an account and evaluative assessment of advances in the technology for producing liquid energy fuels from syngas and to suggest opportunities for future research deemed promising for practical processes. Much of the improved technology for selective synthesis of desired fuels from syngas has resulted from advances in catalytic chemistry. However, novel process engineering has been particularly important recently, utilizing known catalysts in new configurations to create new catalytic processes. This report is an update of the 1988 study Catalysts for Fuels from Syngas: New Directions for Research (Mills 1988), which is included as Appendix A. Technology for manufacture of syngas is not part of this study. The manufacture of liquid synfuels is capital intensive. Thus, in evaluating advances in fuels technology, focus is on the potential for improved economics, particularly on lowering plant investment costs. A second important criteria is the potential for environmental benefits. The discussion is concerned with two types of hydrocarbon fuels and three types of oxygenate fuels that can be synthesized from syngas. Seven alternative reaction pathways are involved.

  9. Ethanol synthesis and water gas shift over bifunctional sulfide catalysts. Final technical progress report, September 12, 1991--December 11, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Klier, K.; Herman, R.G.; Deemer, M.; Richards-Babb, M.; Carr, T.

    1995-07-01

    The objective of this research was to investigate sulfur-resistant catalysts for the conversion of synthesis gas having H{sub 2}/CO {le} 1 into C{sub 1}--C{sub 4} alcohols, especially ethanol, by a highly selective and efficient pathway, while also promoting the water gas shift reaction (WGSR). The catalysts chosen are bifunctional, base-hydrogenation, sulfur-tolerant transition metal sulfides with heavy alkali, e.g. Cs{sup +}, promoter dispersed on their surfaces. The modes of activation of H{sub 2} and CO on MoS{sub 2} and alkali-doped MoS{sub 2} were considered, and computational analyses of the thermodynamic stability of transition metal sulfides and of the electronic structure of these sulfide catalysts were carried out. In the preparation of the cesium-promoted MoS{sub 2} catalysts, a variety of preparation methods using CsOOCH were examined. In all cases, doping with CsOOCH led to a lost of surface area. The undoped molybdenum disulfide catalyst only produced hydrocarbons. Cs-doped MoS{sub 2} catalysts all produced linear alcohols, along with smaller amounts of hydrocarbons. With a 20 wt% CsOOCH/MoS{sub 2} catalyst, temperature, pressure, and flow rate dependences of the synthesis reactions were investigated in the presence and absence of H{sub 2}S in the H{sub 2}/CO = 1/1 synthesis gas during short term testing experiments. It was shown that with a carefully prepared 10 wt% CsOOCH/MoS{sub 2} catalyst, reproducible and high alcohol synthesis activity could be obtained. For example, at 295 C with H{sub 2}/CO = 1 synthesis gas at 8.3 MPa and with GHSV = 7,760 l/kg cat/hr, the total alcohol space time yield was ca 300 g/kg cat/hr (accompanied with a hydrocarbon space time yield of ca 60 g/kg cat/hr). Over a testing period of ca 130 hr, no net deactivation of the catalyst was observed. 90 refs., 82 figs., 14 tabs.

  10. Process analysis of an oxygen lean oxy-fuel power plant with co-production of synthesis gas

    International Nuclear Information System (INIS)

    Normann, Fredrik; Thunman, Henrik; Johnsson, Filip

    2009-01-01

    This paper investigates new possibilities and synergy effects for an oxy-fuel fired polygeneration scheme (transportation fuel and electricity) with carbon capture and co-firing of biomass. The proposed process has the potential to make the oxy-fuel process more effective through a sub-stoichiometric combustion in-between normal combustion and gasification, which lowers the need for oxygen within the process. The sub-stoichiometric combustion yields production of synthesis gas, which is utilised in an integrated synthesis to dimethyl ether (DME). The process is kept CO 2 neutral through co-combustion of biomass in the process. The proposed scheme is simulated with a computer model with a previous study of an oxy-fuel power plant as a reference process. The degree of sub-stoichiometric combustion, or amount of synthesis gas produced, is optimised with respect to the overall efficiency. The maximal efficiency was found at a stoichiometric ratio just below 0.6 with the efficiency for the electricity producing oxy-fuel process of 0.35 and a DME process efficiency of 0.63. It can be concluded that the proposed oxygen lean combustion process constitutes a way to improve the oxy-fuel carbon capture processes with an efficient production of DME in a polygeneration process

  11. Fluidized bed gasification of high tonnage sorghum, cotton gin trash and beef cattle manure: Evaluation of synthesis gas production

    International Nuclear Information System (INIS)

    Maglinao, Amado L.; Capareda, Sergio C.; Nam, Hyungseok

    2015-01-01

    Highlights: • High tonnage sorghum, cotton gin trash and beef cattle manure were characterized and gasified in a fluidized bed reactor. • Biomass gasification at 730 °C and ER = 0.35 produced synthesis gas with an average energy content of 4.19 MJ Nm −3 . • Synthesis gas heating value and yield were relatively constant at reaction temperatures from 730 °C to 800 °C. • Optimum hydrogen production on HTS gasification was achieved at 780 °C temperature and ER of 0.4. - Abstract: Fluidized bed gasification using high-tonnage sorghum, cotton gin trash and beef cattle manure was performed in a pilot scale bubbling fluidized bed reactor equipped with the necessary feedback control system. Characterization of biomass showed that the high-tonnage sorghum had the highest energy and carbon content of 19.58 MJ kg −1 and 42.29% wt , respectively among the three feed stocks. At 730 °C reaction temperature and equivalence ratio of 0.35, comparable yields of methane, nitrogen and carbon dioxide (within ± 1.4% vol ) were observed in all three feed stocks. The gasification system produced synthesis gas with an average heating value of 4.19 ± 0.09 MJ Nm −3 and an average yield of 1.98 ± 0.1 Nm 3 kg −1 of biomass. Carbon conversion and gasification efficiencies indicated that most of the carbon was converted to gaseous products (85% average ) while 48% average of the energy from the biomass was converted into combustible gas. The production of hydrogen was significantly affected by the biomass used during gasification. The synthesis gas heating value and yield were relatively constant at reaction temperatures from 730 °C to 800 °C. Utilizing high-tonnage sorghum, the optimum hydrogen production during gasification was achieved at a reaction temperature of 780 °C and an equivalence ratio of 0.40.

  12. Continuous gas/liquid–liquid/liquid flow synthesis of 4-fluoropyrazole derivatives by selective direct fluorination

    Directory of Open Access Journals (Sweden)

    Jessica R. Breen

    2011-08-01

    Full Text Available 4-Fluoropyrazole systems may be prepared by a single, sequential telescoped two-step continuous gas/liquid–liquid/liquid flow process from diketone, fluorine gas and hydrazine starting materials.

  13. Synthesis Methods, Microscopy Characterization and Device Integration of Nanoscale Metal Oxide Semiconductors for Gas Sensing in Aerospace Applications

    Science.gov (United States)

    VanderWal, Randy L.; Berger, Gordon M.; Kulis, Michael J.; Hunter, Gary W.; Xu, Jennifer C.; Evans, Laura J.

    2009-01-01

    A comparison is made between SnO2, ZnO, and TiO2 single-crystal nanowires and SnO2 polycrystalline nanofibers for gas sensing. Both nanostructures possess a one-dimensional morphology. Different synthesis methods are used to produce these materials: thermal evaporation-condensation (TEC), controlled oxidation, and electrospinning. Advantages and limitations of each technique are listed. Practical issues associated with harvesting, purification, and integration of these materials into sensing devices are detailed. For comparison to the nascent form, these sensing materials are surface coated with Pd and Pt nanoparticles. Gas sensing tests, with respect to H2, are conducted at ambient and elevated temperatures. Comparative normalized responses and time constants for the catalyst and noncatalyst systems provide a basis for identification of the superior metal-oxide nanostructure and catalyst combination. With temperature-dependent data, Arrhenius analyses are made to determine an activation energy for the catalyst-assisted systems.

  14. Engineering Development of Ceramic Membrane Reactor System for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Air Products and Chemicals

    2008-09-30

    An Air Products-led team successfully developed ITM Syngas technology from the concept stage to a stage where a small-scale engineering prototype was about to be built. This technology produces syngas, a gas containing carbon monoxide and hydrogen, by reacting feed gas, primarily methane and steam, with oxygen that is supplied through an ion transport membrane. An ion transport membrane operates at high temperature and oxygen ions are transported through the dense membrane's crystal lattice when an oxygen partial pressure driving force is applied. This development effort solved many significant technical challenges and successfully scaled-up key aspects of the technology to prototype scale. Throughout the project life, the technology showed significant economic benefits over conventional technologies. While there are still on-going technical challenges to overcome, the progress made under the DOE-funded development project proved that the technology was viable and continued development post the DOE agreement would be warranted.

  15. Combustion of coal gas fuels in a staged combustor

    Science.gov (United States)

    Rosfjord, T. J.; Mcvey, J. B.; Sederquist, R. A.; Schultz, D. F.

    1982-01-01

    Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

  16. Controlled synthesis of ZnO hollow microspheres via precursor-template method and its gas sensing property

    International Nuclear Information System (INIS)

    Tian, Yu; Li, Jinchai; Xiong, Hui; Dai, Jiangnan

    2012-01-01

    Highlights: ► Zn powder as precursor template for synthesis ZnO hollow spheres. ► Different precursor templates result in different ZnO nanostructures. ► Different experimental conditions enable growth of different surface morphologies of ZnO sphere. ► ZnO hollow sphere materials have good gas sensing performance for detecting ethanol gas. - Abstract: Using Zn powder as precursor templates, ZnO hollow microspheres were successfully prepared by thermal evaporation method and characterized by X-ray diffraction analysis, scanning electron microscope and transmission electron microscope. It was found that different size and shape of precursor resulted in different ZnO nanostructures. When varying experimental conditions, such as air flow rate and working pressure, ZnO hollow spheres with different surface morphologies could be obtained. The advantages of the present synthetic technology are simple, relatively low cost, and high reproducibility. A gas sensor was fabricated from the as-prepared ZnO hollow microspheres and tested to the ethanol gas at different operating temperatures.

  17. Rapid One-Pot Microwave Synthesis of Mixed-Linker Hybrid Zeolitic-Imidazolate Framework Membranes for Tunable Gas Separations.

    Science.gov (United States)

    Hillman, Febrian; Brito, Jordan; Jeong, Hae-Kwon

    2018-02-14

    The relatively slow and complex fabrication processes of polycrystalline metal-organic framework (MOF) membranes often times restrict their way to commercialization, despite their potential for molecular separation applications. Herein, we report a rapid one-pot microwave synthesis of mixed-linker hybrid zeolitic-imidazolate framework (ZIF) membranes consisting of 2-methylimidazolate (ZIF-8 linker) and benzimidazolate (ZIF-7 linker) linkers, termed ZIF-7-8 membranes. The fast-volumetric microwave heating in conjunction with a unique counter diffusion of metal and linker solutions enabled unprecedented rapid synthesis of well-intergrown ZIF-7-8 membranes in ∼90 s, the fastest MOF membrane preparation up to date. Furthermore, we were able to tune the molecular sieving properties of the ZIF-7-8 membranes by varying the benzimidazole-to-2-methylimidazole (bIm-to-mIm) linker ratio in the hybrid frameworks. The tuning of their molecular sieving properties led to the systematic change in the permeance and selectivity of various small gases. The unprecedented rapid synthesis of well-intergrown ZIF-7-8 membranes with tunable molecular sieving properties is an important step forward for the commercial gas separation applications of ZIF membranes.

  18. Synthesis and Characterization of Cobalt Containing Nanoparticles on Alumina A Potential Catalyst for Gas to Liquid Fuels Production

    Science.gov (United States)

    Cowen, Jonathan; Hepp, Aloysius F.

    2016-01-01

    Fisher-Tröpsch synthesis (FTS) is a century-old gas-to-liquid (GTL) technology that commonly employs cobalt (Co, on an oxide support) or iron (supported or not) species catalysts. It has been well established that the activity of the Co catalyst depends directly upon the number of surface Co atoms. The addition of promoter (mainly noble) metals has been widely utilized to increase the fraction of Co that is available for surface catalysis. Direct synthesis of Co nanoparticles is a possible alternative approach; our preliminary synthesis and characterization efforts are described. Materials were characterized by various transmission microscopies and energy dispersive spectroscopy. Tri-n-octylphosphine oxide (TOPO) and dicobalt octacarbonyl were heated under argon to a temperature of 180 deg with constant stirring for 1 hr. Quenching the reaction in toluene produced Co-containing nanoparticles with a diameter of 5 to 10 nm. Alternatively, an alumina support (SBA-200 Al2O3) was added; the reaction was further stirred and the temperature was decreased to 140 deg to reduce the rate of further growth/ripening of the nucleated Co nanoparticles. A typical size of Co-containing NPs was also found to be in the range of 5 to 10 nm. This can be contrasted with a range of 50 to 200 nm for conventionally-produced Co-Al2O3 Fischer-Tröpsch catalysts. This method shows great potential for production of highly dispersed catalysts that are either supported or unsupported.

  19. Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup, and Oxygen Separation Equipment; Task 9: Mixed Alcohols From Syngas -- State of Technology

    Energy Technology Data Exchange (ETDEWEB)

    Nexant Inc.

    2006-05-01

    This deliverable is for Task 9, Mixed Alcohols from Syngas: State of Technology, as part of National Renewable Energy Laboratory (NREL) Award ACO-5-44027, ''Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup and Oxygen Separation Equipment''. Task 9 supplements the work previously done by NREL in the mixed alcohols section of the 2003 technical report Preliminary Screening--Technical and Economic Assessment of Synthesis Gas to Fuels and Chemicals with Emphasis on the Potential for Biomass-Derived Syngas.

  20. Synthesis of a catalytic reactor membrane for synthesis gas production; Elaboration d'une membrane de reacteur catalytique pour la production de gaz de synthese

    Energy Technology Data Exchange (ETDEWEB)

    Juste, E.; Julian, A.; Chartier, T. [Limoges Univ., Lab. Science des Procedes Ceramiques et de Traitements de Surface (SPCTS, UMR 6638 CNRS), 87 (France); Juste, E.; Julian, A.; Del Gallo, P.; Richet, N. [Centre de Recherche Claude-Delorme, Air Liquide, 78 - Jouy en Josas (France)

    2007-07-01

    The conversion of natural gas to synthesis gas (mixture of H{sub 2} and CO) is a main challenge for the hydrogen and clean fuels production. Mixed (ionic O{sup 2-} and electronic) conducing ceramics membrane reactors seem particularly promising. The design considered for the membrane is a tri-layer system integrating a reforming catalyst and a dense membrane laying on a porous support. Among the materials considered for the dense membrane, perovskites La{sub 1-x}Sr{sub x}Fe{sub 1-y}Ga{sub y}O{sub 3-{delta}} seem to be interesting for their performances and stability. The oxygen flux through the membrane is measured in terms of temperature under different oxygen partial pressure gradients. In the industrial experimental conditions, the membrane is submitted to a strong oxygen (air/methane) partial pressure gradient of about 900 C which induces mechanical stresses, on account of the material expansion difference, in terms of p{sub O2}. In this framework, the evolutions of the performances and of the expansion coefficient have been followed in terms of the substitutions rates in La{sub (1-x)}Sr{sub x}Fe{sub (1-y)}Ga{sub y}O{sub 3-{delta}} with x{<=}0.5 and y{<=}0.5. (O.M.)

  1. Synthesis, characterization and gas sensitivity of MoO3 nanoparticles

    Indian Academy of Sciences (India)

    TECS

    Sol–gel citrate; metal oxide; gas sensing; nanoparticles; SEM. 1. Introduction ... et al (2005) demonstrated the advantageous use of nano- structured cerium oxide .... Hoffheins B, Taylor R F and Schultz J S (eds) 1996 Solid state resistive gas ...

  2. Synthesis of the report on the french gas market opening 24 october 2002

    International Nuclear Information System (INIS)

    Syrota, J.

    2002-10-01

    This document takes stock on the french gas market opening since august 2000, date of putting into force of the Directive 98/30/CE and proposes recommendations, after taking concerned parties opinion, on the the main questions relative to the future gas regulation: the market, the european harmonization, the tariffs, the distribution access, the transparency. (A.L.B.)

  3. Managing of gas sensing characteristic of a reduced graphene oxide based gas sensor by the change in synthesis condition: A new approach for electronic nose design

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Taher, E-mail: talizadeh@ut.ac.ir [Department of Analytical Chemistry, Faculty of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of); Hamedsoltani, Leyla [Department of Applied Chemistry, Faculty of Science, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of)

    2016-11-01

    Natural graphite was oxidized and exfoliated via two different methods, leading to two types of graphene oxide (GO) materials. The obtained materials were reduced by three different reducing agents including: hydrazine hydrate, ascorbic acid and sodium borohydride, giving thus six kinds of reduced graphene oxide (RGO) materials. The obtained materials were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The RGOs were then used to fabricate different gas sensors and their electrical resistances were recorded upon exposing to various volatile organic compounds vapors (VOCs). Gas sensing selectivity of each RGO was significantly affected by the synthesis condition. The RGO-based sensor array was fabricated and its capability for discrimination of seven kinds of VOCs was evaluated, utilizing principal component analysis and cluster analysis methods. Loading plot indicated that the presence of five RGO-based sensors could effectively discriminate the aimed vapors. The electronic nose, containing five kinds of RGOs, was used for the classification of seven kinds of VOCs at their different concentrations. - Highlights: • Two oxidation procedures and three reducing agents were utilized to produce six kinds of RGOs. • The synthesized different RGOs exhibited significantly different sensing behaviors. • Seven kinds of organic vapors were chosen for the evaluation of discrimination power of EN. • Using PCA, it was found that seven of six RFGOs were appropriate number to use in final EN. • The developed EN was capable of properly discrimination of tested vapors.

  4. Gas

    International Nuclear Information System (INIS)

    1996-01-01

    The French government has decided to modify the conditions of extension of local natural gas authorities to neighbouring districts. The European Union is studying the conditions of internal gas market with the objective of more open markets although considering public service requirements

  5. Gas-phase plasma synthesis of free-standing silicon nanoparticles for future energy applications

    NARCIS (Netherlands)

    Doğan, I.; van de Sanden, M.C.M.

    2016-01-01

    Silicon nanoparticles (Si-NPs) are considered as possible candidates for a wide spectrum of future technological applications. Research in the last decades has shown that plasmas are one of the most suitable environments for the synthesis of Si-NPs. This review discusses the unique size-dependent

  6. Gas-Phase Plasma Synthesis of Free-Standing Silicon Nanoparticles for Future Energy Applications

    NARCIS (Netherlands)

    Dogan, I.; van de Sanden, M. C. M.

    2016-01-01

    Silicon nanoparticles (Si-NPs) are considered as possible candidates for a wide spectrum of future technological applications. Research in the last decades has shown that plasmas are one of the most suitable environments for the synthesis of Si-NPs. This review discusses the unique size-dependent

  7. Production of synthesis gas and methane via coal gasification utilizing nuclear heat

    International Nuclear Information System (INIS)

    van Heek, K.H.; Juentgen, H.

    1982-01-01

    The steam gasificaton of coal requires a large amount of energy for endothermic gasification, as well as for production and heating of the steam and for electricity generation. In hydrogasification processes, heat is required primarily for the production of hydrogen and for preheating the reactants. Current developments in nuclear energy enable a gas cooled high temperature nuclear reactor (HTR) to be the energy source, the heat produced being withdrawn from the system by means of a helium loop. There is a prospect of converting coal, in optimal yield, into a commercial gas by employing the process heat from a gas-cooled HTR. The advantages of this process are: (1) conservation of coal reserves via more efficient gas production; (2) because of this coal conservation, there are lower emissions, especially of CO 2 , but also of dust, SO 2 , NO/sub x/, and other harmful substances; (3) process engineering advantages, such as omission of an oxygen plant and reduction in the number of gas scrubbers; (4) lower gas manufacturing costs compared to conventional processes. The main problems involved in using nuclear energy for the industrial gasification of coal are: (1) development of HTRs with helium outlet temperatures of at least 950 0 C; (2) heat transfer from the core of the reactor to the gas generator, methane reforming oven, or heater for the hydrogenation gas; (3) development of a suitable allothermal gas generator for the steam gasification; and (4) development of a helium-heated methane reforming oven and adaption of the hydrogasification process for operation in combination with the reactor. In summary, processes for gasifying coal that employ heat from an HTR have good economic and technical prospects of being realized in the future. However, time will be required for research and development before industrial application can take place. 23 figures, 4 tables. (DP)

  8. Controlled Synthesis of Hierarchically Assembled Porous ZnO Microspheres with Enhanced Gas-Sensing Properties

    Directory of Open Access Journals (Sweden)

    Shengsheng You

    2015-01-01

    Full Text Available The ZnO microspheres constructed by porous nanosheets were successfully synthesized by calcinating zinc hydroxide carbonate (ZHC microspheres obtained by a sample hydrothermal method. The samples were characterized in detail with scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD, and thermogravimetric and differential scanning calorimetry (TG-DSC. The results indicated that the prepared ZnO microspheres were well crystalline with wurtzite hexagonal phase. The effects of reaction time, temperature, the amount of trisodium citrate, and urea on the morphology of ZnO microspheres were studied. The formation mechanism of porous ZnO microspheres was discussed. Furthermore, the gas-sensing properties for detection of organic gas of the prepared porous ZnO microspheres were investigated. The results indicated that the prepared porous ZnO microspheres exhibited high gas-sensing properties for detection of ethanol gas.

  9. Integrated Biorefinery for Conversion of Biomass to Ethanol, Synthesis Gas, and Heat

    Energy Technology Data Exchange (ETDEWEB)

    Leon, Gerson [Abengoa Bioenergy, Hugoton, KS (United States)

    2017-06-20

    Goal of the project was to Design, build and operate a commercial scale bioethanol facility that uses sustainable biomass feedstock, drastically reduces greenhouse gas (GHG) emissions while achieving output production, yield and cost targets.

  10. Synthesis and Characterization of Quaternary Metal Chalcogenide Aerogels for Gas Separation and Volatile Hydrocarbon Adsorption

    KAUST Repository

    Edhaim, Fatimah A.

    2017-01-01

    as sorbents for selective gas separation and volatile organic compounds adsorption. They showed preferential adsorption of polarizable gases (CO2) and organic compounds (toluene). Ion exchange and heavy metal remediation properties have also been demonstrated

  11. TiO2 Nanotubes: Recent Advances in Synthesis and Gas Sensing Properties

    Directory of Open Access Journals (Sweden)

    Giorgio Sberveglieri

    2013-10-01

    Full Text Available Synthesis—particularly by electrochemical anodization-, growth mechanism and chemical sensing properties of pure, doped and mixed titania tubular arrays are reviewed. The first part deals on how anodization parameters affect the size, shape and morphology of titania nanotubes. In the second part fabrication of sensing devices based on titania nanotubes is presented, together with their most notable gas sensing performances. Doping largely improves conductivity and enhances gas sensing performances of TiO2 nanotubes

  12. Synthesis, fractionation, and thin film processing of nanoparticles using the tunable solvent properties of carbon dioxide gas expanded liquids

    Science.gov (United States)

    Anand, Madhu

    Nanoparticles have received significant attention because of their unusual characteristics including high surface area to volume ratios. Materials built from nanoparticles possess unique chemical, physical, mechanical and optical properties. Due to these properties, they hold potential in application areas such as catalysts, sensors, semiconductors and optics. At the same time, CO 2 in the form of supercritical fluid or CO2 gas-expanded liquid mixtures has gained significant attention in the area of processing nanostructures. This dissertation focuses on the synthesis and processing of nanoparticles using CO2 tunable solvent systems. Nanoparticle properties depend heavily on their size and, as such, the ability to finely control the size and uniformity of nanoparticles is of utmost importance. Solution based nanoparticle formation techniques are attractive due to their simplicity, but they often result in the synthesis of particles with a wide size range. To address this limitation, a post-synthesis technique has been developed in this dissertation to fractionate polydisperse nanoparticles ( s . = 30%) into monodisperse fractions ( s . = 8%) using tunable physicochemical properties of CO 2 expanded liquids, where CO2 is employed as an antisolvent. This work demonstrates that by controlling the addition of CO2 (pressurization) to an organic dispersion of nanoparticles, the ligand stabilized nanoparticles can be size selectively precipitated within a novel high pressure apparatus that confines the particle precipitation to a specified location on a surface. Unlike current techniques, this CO2 expanded liquid approach provides faster and more efficient particle size separation, reduction in organic solvent usage, and pressure tunable size selection in a single process. To improve our fundamental understanding and to further refine the size separation process, a detailed study has been performed to identify the key parameters enabling size separation of various

  13. Magnesium carbide synthesis from methane and magnesium oxide - a potential methodology for natural gas conversion to premium fuels and chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, A.F.; Modestino, A.J.; Howard, J.B. [Massachusetts Institute of Technology, Cambridge, MA (United States)] [and others

    1995-12-31

    Diversification of the raw materials base for manufacturing premium fuels and chemicals offers U.S. and international consumers economic and strategic benefits. Extensive reserves of natural gas in the world provide a valuable source of clean gaseous fuel and chemical feedstock. Assuming the availability of suitable conversion processes, natural gas offers the prospect of improving flexibility in liquid fuels and chemicals manufacture, and thus, the opportunity to complement, supplement, or displace petroleum-based production as economic and strategic considerations require. The composition of natural gas varies from reservoir to reservoir but the principal hydrocarbon constituent is always methane (CH{sub 4}). With its high hydrogen-to-carbon ratio, methane has the potential to produce hydrogen or hydrogen-rich products. However, methane is a very chemically stable molecule and, thus, is not readily transformed to other molecules or easily reformed to its elements (H{sub 2} and carbon). In many cases, further research is needed to augment selectivity to desired product(s), increase single-pass conversions, or improve economics (e.g. there have been estimates of $50/bbl or more for liquid products) before the full potential of these methodologies can be realized on a commercial scale. With the trade-off between gas conversion and product selectivity, a major challenge common to many of these technologies is to simultaneously achieve high methane single-pass conversions and high selectivity to desired products. Based on the results of the scoping runs, there appears to be strong indications that a breakthrough has finally been achieved in that synthesis of magnesium carbides from MgO and methane in the arc discharge reactor has been demonstrated.

  14. A novel zinc(II) metal–organic framework with a diamond-like structure: synthesis, study of thermal robustness and gas adsorption properties

    Czech Academy of Sciences Publication Activity Database

    Almáši, M.; Zeleňák, V.; Zukal, Arnošt; Kuchár, J.; Čejka, Jiří

    2016-01-01

    Roč. 45, č. 3 (2016), s. 1233-1242 ISSN 1477-9226 R&D Projects: GA ČR GA14-07101S Institutional support: RVO:61388955 Keywords : synthesis * gas adsorption properties * physical chemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.029, year: 2016

  15. Design of adiabatic fixed-bed reactors for the partial oxidation of methane to synthesis gas. Application to production of methanol and hydrogen-for-fuel-cells

    NARCIS (Netherlands)

    Smet, de C.R.H.; Croon, de M.H.J.M.; Berger, R.J.; Marin, G.B.M.M.; Schouten, J.C.

    2001-01-01

    Adiabatic fixed-bed reactors for the catalytic partial oxidn. (CPO) of methane to synthesis gas were designed at conditions suitable for the prodn. of methanol and hydrogen-for-fuel-cells. A steady-state, one-dimensional heterogeneous reactor model was applied in the simulations. Intra-particle

  16. The reaction mechanism of the partial oxidation of methane to synthesis gas: a transient kinetic study over rhodium and a comparison with platinum

    NARCIS (Netherlands)

    Mallens, E.P.J.; Hoebink, J.H.B.J.; Marin, G.B.M.M.

    1997-01-01

    The partial oxidation of methane to synthesis gas over rhodium sponge has been investigated by admitting pulses of pure methane and pure oxygen as well as mixtures of methane and oxygen to rhodium sponge at temperatures from 873 to 1023 K. Moreover, pulses of oxygen followed by methane and vice

  17. Optimization of a corn steep medium for production of ethanol from synthesis gas fermentation by Clostridium ragsdalei.

    Science.gov (United States)

    Saxena, Jyotisna; Tanner, Ralph S

    2012-04-01

    Fermentation of biomass derived synthesis gas to ethanol is a sustainable approach that can provide more usable energy and environmental benefits than food-based biofuels. The effects of various medium components on ethanol production by Clostridium ragsdalei utilizing syngas components (CO:CO(2)) were investigated, and corn steep liquor (CSL) was used as an inexpensive nutrient source for ethanol production by C. ragsdalei. Elimination of Mg(2+), NH(4) (+) and PO(4) (3-) decreased ethanol production from 38 to 3.7, 23 and 5.93 mM, respectively. Eliminating Na(+), Ca(2+), and K(+) or increasing Ca(2+), Mg(2+), K(+), NH(4) (+) and PO(4) (3-) concentrations had no effect on ethanol production. However, increased Na(+) concentration (171 mM) inhibited growth and ethanol production. Yeast extract (0.5 g l(-1)) and trace metals were necessary for growth of C. ragsdalei. CSL alone did not support growth and ethanol production. Nutrients limiting in CSL were trace metals, NH(4) (+) and reducing agent (Cys: cysteine sulfide). Supplementation of trace metals, NH(4) (+) and CyS to CSL (20 g l(-1), wet weight basis) yielded better growth and similar ethanol production as compared to control medium. Using 10 g l(-1), the nutritional limitation led to reduced ethanol production. Higher concentrations of CSL (50 and 100 g l(-1)) were inhibitory for cell growth and ethanol production. The CSL could replace yeast extract, vitamins and minerals (excluding NH(4) (+)). The optimized CSL medium produced 120 and 50 mM of ethanol and acetate, respectively. The CSL could provide as an inexpensive source of most of the nutrients required for the syngas fermentation, and thus could improve the economics of ethanol production from biomass derived synthesis gas by C. ragsdalei.

  18. Synthesis of highly c-oriented ZIF-69 membranes by secondary growth and their gas permeation properties

    KAUST Repository

    Liu, Yunyang; Zeng, Gaofeng; Pan, Yichang; Lai, Zhiping

    2011-01-01

    A seeded growth procedure was successfully developed to synthesize highly c-oriented and well-intergrown zeolitic imidazolate framework-69 (ZIF-69) membranes on porous α-alumina substrates. The synthesis conditions were optimized both for seed preparation and for secondary growth. For seeding, a facile method was developed to prepare smaller and flat ZIF-69 microcrystals in order to make thin and c-oriented seed layers. While for secondary growth, a synthesis condition that favored the growth along the c-direction was chosen in order to form highly c-oriented ZIF-69 membranes after growth. As a result, the majority of ZIF-69 grains inside the membrane have their straight channels along the crystallographic c-axis aligned perpendicularly to the substrate surface. Such alignment was confirmed by both XRD and pole figure analysis. The mixture-gas separation studies that were carried out at room temperature and 1atm gave separation factors of 6.3, 5.0, 4.6 for CO2/N2, CO2/CO and CO2/CH4 respectively, and a permeance of ∼1.0×10-7molm-2s-1Pa-1 for CO2 in almost all mixtures. Both the separation factor and permeance were better than the performance of the ZIF-69 membranes prepared by the in situ solvothermal method due to improvement in the membrane microstructure by the seeded growth method. © 2011 Elsevier B.V.

  19. Synthesis of highly c-oriented ZIF-69 membranes by secondary growth and their gas permeation properties

    KAUST Repository

    Liu, Yunyang

    2011-09-01

    A seeded growth procedure was successfully developed to synthesize highly c-oriented and well-intergrown zeolitic imidazolate framework-69 (ZIF-69) membranes on porous α-alumina substrates. The synthesis conditions were optimized both for seed preparation and for secondary growth. For seeding, a facile method was developed to prepare smaller and flat ZIF-69 microcrystals in order to make thin and c-oriented seed layers. While for secondary growth, a synthesis condition that favored the growth along the c-direction was chosen in order to form highly c-oriented ZIF-69 membranes after growth. As a result, the majority of ZIF-69 grains inside the membrane have their straight channels along the crystallographic c-axis aligned perpendicularly to the substrate surface. Such alignment was confirmed by both XRD and pole figure analysis. The mixture-gas separation studies that were carried out at room temperature and 1atm gave separation factors of 6.3, 5.0, 4.6 for CO2/N2, CO2/CO and CO2/CH4 respectively, and a permeance of ∼1.0×10-7molm-2s-1Pa-1 for CO2 in almost all mixtures. Both the separation factor and permeance were better than the performance of the ZIF-69 membranes prepared by the in situ solvothermal method due to improvement in the membrane microstructure by the seeded growth method. © 2011 Elsevier B.V.

  20. Economics of Undiscovered Oil and Gas in the North Slope of Alaska: Economic Update and Synthesis

    Science.gov (United States)

    Attanasi, E.D.; Freeman, P.A.

    2009-01-01

    The U.S. Geological Survey (USGS) has published assessments by geologists of undiscovered conventional oil and gas accumulations in the North Slope of Alaska; these assessments contain a set of scientifically based estimates of undiscovered, technically recoverable quantities of oil and gas in discrete oil and gas accumulations that can be produced with conventional recovery technology. The assessments do not incorporate economic factors such as recovery costs and product prices. The assessors considered undiscovered conventional oil and gas resources in four areas of the North Slope: (1) the central North Slope, (2) the National Petroleum Reserve in Alaska (NPRA), (3) the 1002 Area of the Arctic National Wildlife Refuge (ANWR), and (4) the area west of the NPRA, called in this report the 'western North Slope'. These analyses were prepared at different times with various minimum assessed oil and gas accumulation sizes and with slightly different assumptions. Results of these past studies were recently supplemented with information by the assessment geologists that allowed adjustments for uniform minimum assessed accumulation sizes and a consistent set of assumptions. The effort permitted the statistical aggregation of the assessments of the four areas composing the study area. This economic analysis is based on undiscovered assessed accumulation distributions represented by the four-area aggregation and incorporates updates of costs and technological and fiscal assumptions used in the initial economic analysis that accompanied the geologic assessment of each study area.

  1. Zinc oxide hollow micro spheres and nano rods: Synthesis and applications in gas sensor

    International Nuclear Information System (INIS)

    Jamil, Saba; Janjua, Muhammad Ramzan Saeed Ashraf; Ahmad, Tauqeer; Mehmood, Tahir; Li, Songnan; Jing, Xiaoyan

    2014-01-01

    Zinc oxide nano rods and micro hollow spheres are successfully fabricated by adopting a simple solvo-thermal approach without employing any surfactant/template by keeping heating time as variable. The prepared products are characterized by using different instruments such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In order to investigate the morphological dependence on the reaction time, analogous experiments with various reaction times are carried out. Depending upon heating time, different morphological forms have been identified such as hollow microsphere (4 μm to 5 μm) and nano rods with an average diameter of approximately 100 nm. The fabricated materials are also tested for ethanol gas sensor applications and zinc oxide hollow microsphere proven to be an efficient gas sensing materials. Nitrogen adsorption–desorption measurement was performed to understand better performance of zinc oxide micro hollow spheres as effective ethanol gas sensing material. - Graphical abstract: Graphical abstract is represented by zinc oxide sphere (prepared by simple solvothermal approach), its XRD pattern(characterization) and finally its application in gas sensing. - Highlights: • Zinc oxide spheres were prepared by using solvothermal method. • Detailed description of the morphology of microspheres assembled by nano rods. • Formation mechanism of zinc oxide spheres assembled by nano rods. • Zinc oxide spheres and nano rods displayed very good gas sensing ability

  2. 3D-modelling of bifunctional core-shell catalysts for the production of fuels from biomass-based synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Wenjin; Lee, Seung Cheol; Li, Hui; Pfeifer, Peter; Dittmeyer, Roland [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Micro Process Engineering (IMVT)

    2013-09-01

    Until now, the main route for the production of DME from synthesis gas in industry is methanol synthesis on a metallic catalyst and subsequent dehydration of methanol on an acid catalyst (two-step process). A single-step process using bifunctional catalysts to perform the two steps simultaneously would be preferred e.g. due to thermodynamic considerations; but this is impeded by the higher volumetric heat release which may cause deactivation of the methanol synthesis catalyst function. Thus we propose to conduct the reaction in a microchannel reactor. However, in order to increase the productivity of the microchannel reactor and to lower the investment costs, we aim at a high selectivity and activity of the catalyst. The continuously removal of methanol by dehydration on an acidic ZSM-5 catalyst as shell improves the thermodynamic conditions of methanol synthesis in the CuO/ZnO/Al{sub 2}O{sub 3} core; thus, the synthesis gas conversion can be higher than that determined by the thermodynamics of pure methanol synthesis. The molecular sieving in the zeolite layer can further lead to higher selectivity of DME at milder reaction conditions. However, mass transport limitation of the synthesis gas to the catalyst core should not hinder the reaction, and therefore a more detailed investigation is required. In order to computer-aided optimize the catalyst structure and the operating conditions for core-shell catalysts, a simulation model should be developed to study the coupled reaction and transport processes in core-shell catalysts. In this simulation model the complicated interaction of diffusion and reaction in the zeolite layer (shell) must be detailed by a network model to describe its structure and the mechanisms effectively. In addition, suitable diffusion and kinetic models are required to describe the mass transport and reactions in the layer. Suitable networks, diffusion and kinetic models are discussed for 3D simulations in this contribution. (orig.)

  3. Second row transition metal sulfides for the hydrotreatment of coal-derived naphtha. 1. Catalyst preparation, characterization and comparison of rate of simultaneous removal of total sulfur, nitrogen and oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Raje, A.P.; Liaw, S.-J.; Srinivasan, R.; Davis, B.H. [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

    1997-03-13

    Naphtha derived from an Illinois No. 6 coal contains appreciable quantities of sulfur-, nitrogen- and oxygen-containing compounds. The hydrotreatment of this naphtha was evaluated over unsupported transition metal sulfide catalysts (Ru, Rh, Mo, Pd, Zr, Mb). The catalysts were prepared by a room temperature precipitation reaction. Surface areas, crystalline phase and particle size distributions were determined by Brunauer-Emmet-Teller (BET), X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. A comparison of average particle sizes calculated from these three techniques has enable the understanding of the morphology of the transition metal sulfides. The catalysts exhibit a so-called volcano plot for the HDS of dibenzothiophene. Similar so-called volcano plots are also exhibited for the simultaneous hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and the hydrodeoxygenation (HDO) of the coal-derived naphtha containing a mixture of heteroatoms. The order of reactivity of the transition metal catalysts is the same for all three of the processes. Ruthenium sulfide is the most active catalyst for HDS, HDN and HDO of the coal-derived naphtha. 22 refs., 3 figs., 4 tabs.

  4. Synthesis and Transport Properties of Novel MOF/PIM-1/MOF Sandwich Membranes for Gas Separation.

    Science.gov (United States)

    Fuoco, Alessio; Khdhayyer, Muhanned R; Attfield, Martin P; Esposito, Elisa; Jansen, Johannes C; Budd, Peter M

    2017-02-11

    Metal-organic frameworks (MOFs) were supported on polymer membrane substrates for the fabrication of composite polymer membranes based on unmodified and modified polymer of intrinsic microporosity (PIM-1). Layers of two different MOFs, zeolitic imidazolate framework-8 (ZIF-8) and Copper benzene tricarboxylate ((HKUST-1), were grown onto neat PIM-1, amide surface-modified PIM-1 and hexamethylenediamine (HMDA) -modified PIM-1. The surface-grown crystalline MOFs were characterized by a combination of several techniques, including powder X-ray diffraction, infrared spectroscopy and scanning electron microscopy to investigate the film morphology on the neat and modified PIM-1 membranes. The pure gas permeabilities of He, H₂, O₂, N₂, CH₄, CO₂ were studied to understand the effect of the surface modification on the basic transport properties and evaluate the potential use of these membranes for industrially relevant gas separations. The pure gas transport was discussed in terms of permeability and selectivity, highlighting the effect of the MOF growth on the diffusion coefficients of the gas in the new composite polymer membranes. The results confirm that the growth of MOFs on polymer membranes can enhance the selectivity of the appropriately functionalized PIM-1, without a dramatic decrease of the permeability.

  5. Conversion of forest residues to a clean gas for fuel or synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Feldmann, H.F.; Liu, K.T.; Longanbach, J.R.; Curran, L.M.; Chauhan, S.P.

    1979-01-01

    A program is described for developing a gasification system specifically for wood and other biomass materials which allows greatly increased gasifier throughputs and direct catalysis of wood. Wood ash, which is a by-product of a wood gasification plant, can be used as a gasification catalyst for wood, as it increases gasification rates and promotes the water-gas shift reaction. The high reactivity of even uncatalyzed biomass allows the potential of very high gasifier throughputs. However, the achievement of this potential requires that the gasifier operate at gas velocities higher than those attainable in conventional reactor systems. Stable and very smooth fluidization with uniform mixing and distribution of chips throughout the bed was observed on addition of an entrained sand phase to a fluidized bed of alumina and wood chips. Economc feasibility studies based on utilization of a proprietary Battelle gasification system which utilizes an entrained-phase heat carrier indicated that an intermediate-Btu gas can be produced in 1000 ton/day plants at a price competitive with liquefied natural gas and No. 2 heating oil.

  6. Tungsten sulfide nanoflakes. Synthesis by electrospinning and their gas sensing properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ke; Qin, Xiang; Deng, Da-Shen; Feng, Xu; Zhang, Chao [Chongqing Univ. of Technology, Chongqing (China). Dept. of Physics and Energy; Feng, Wen-Lin [Chongqing Univ. of Technology, Chongqing (China). Dept. of Physics and Energy; Chongqing Key Laboratory of Modern Photoelectric Detection Technology and Instrument, Chongqing (China).

    2017-07-01

    Tungsten sulfide (WS{sub 2}) nanoflakes were successfully prepared via electrospinning with polyvinylpyrrolidone (PVP) as organic solvent. In addition, Ag-deposited WS{sub 2} (Ag-WS{sub 2}) was obtained by chemical blending/calcination method. The structure and morphology of as-prepared materials were characterised by powder X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The XRD result shows that the prepared WS{sub 2} has a graphene-like structure with P{sub 63/mmc} space group symmetry. The SEM illuminates that the sensing samples have nanoflake appearance. Furthermore, heater-type gas sensors were fabricated based on WS{sub 2} and Ag-WS{sub 2} nanomaterials. The sensing responses of WS{sub 2} and Ag-WS{sub 2} on the ammonia (NH{sub 3}), ethanol (C{sub 2}H{sub 5}OH), and acetone (C{sub 3}H{sub 6}O) were investigated at about 220 C. The results indicate that gas sensor based on WS{sub 2} and Ag-WS{sub 2} nanoflakes has 60 ppm sensing threshold value for ammonia. One possible gas sensing mechanism of WS{sub 2} and Ag-WS{sub 2} gas sensors is surface control via charge transfer.

  7. Gas-phase synthesis of magnesium nanoparticles : A high-resolution transmission electron microscopy study

    NARCIS (Netherlands)

    Kooi, B.J.; Palasantzas, G.; de Hosson, J.T.M.

    2006-01-01

    Magnesium nanoparticles with size above 10 nm, prepared by gas-phase syntheses, were investigated by high-resolution transmission electron microscopy. The dominant particle shape is a hexagonal prism terminated by Mg(0002) and Mg{1010} facets. Oxidation of Mg yields a MgO shell (similar to 3 nm

  8. Synthesis and characterization of polybenzoxazinone and its prepolymer using gas separation

    Czech Academy of Sciences Publication Activity Database

    Pientka, Zbyněk; Brožová, Libuše; Pulyalina, A. Y.; Goikhman, M. Y.; Podeshvo, I. V.; Gofman, I. V.; Saprykina, N. N.; Polotskaya, G. A.

    2013-01-01

    Roč. 214, č. 24 (2013), s. 2867-2874 ISSN 1022-1352 R&D Projects: GA ČR GA104/09/1165 Institutional support: RVO:61389013 Keywords : gas separation * polybenzoxazinone * polymer membranes Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.451, year: 2013

  9. Synthesis and Transport Properties of Novel MOF/PIM-1/MOF Sandwich Membranes for Gas Separation

    Directory of Open Access Journals (Sweden)

    Alessio Fuoco

    2017-02-01

    Full Text Available Metal-organic frameworks (MOFs were supported on polymer membrane substrates for the fabrication of composite polymer membranes based on unmodified and modified polymer of intrinsic microporosity (PIM-1. Layers of two different MOFs, zeolitic imidazolate framework-8 (ZIF-8 and Copper benzene tricarboxylate ((HKUST-1, were grown onto neat PIM-1, amide surface-modified PIM-1 and hexamethylenediamine (HMDA -modified PIM-1. The surface-grown crystalline MOFs were characterized by a combination of several techniques, including powder X-ray diffraction, infrared spectroscopy and scanning electron microscopy to investigate the film morphology on the neat and modified PIM-1 membranes. The pure gas permeabilities of He, H2, O2, N2, CH4, CO2 were studied to understand the effect of the surface modification on the basic transport properties and evaluate the potential use of these membranes for industrially relevant gas separations. The pure gas transport was discussed in terms of permeability and selectivity, highlighting the effect of the MOF growth on the diffusion coefficients of the gas in the new composite polymer membranes. The results confirm that the growth of MOFs on polymer membranes can enhance the selectivity of the appropriately functionalized PIM-1, without a dramatic decrease of the permeability.

  10. Synthesis and Transport Properties of Novel MOF/PIM-1/MOF Sandwich Membranes for Gas Separation

    Science.gov (United States)

    Fuoco, Alessio; Khdhayyer, Muhanned R.; Attfield, Martin P.; Esposito, Elisa; Jansen, Johannes C.; Budd, Peter M.

    2017-01-01

    Metal-organic frameworks (MOFs) were supported on polymer membrane substrates for the fabrication of composite polymer membranes based on unmodified and modified polymer of intrinsic microporosity (PIM-1). Layers of two different MOFs, zeolitic imidazolate framework-8 (ZIF-8) and Copper benzene tricarboxylate ((HKUST-1), were grown onto neat PIM-1, amide surface-modified PIM-1 and hexamethylenediamine (HMDA) -modified PIM-1. The surface-grown crystalline MOFs were characterized by a combination of several techniques, including powder X-ray diffraction, infrared spectroscopy and scanning electron microscopy to investigate the film morphology on the neat and modified PIM-1 membranes. The pure gas permeabilities of He, H2, O2, N2, CH4, CO2 were studied to understand the effect of the surface modification on the basic transport properties and evaluate the potential use of these membranes for industrially relevant gas separations. The pure gas transport was discussed in terms of permeability and selectivity, highlighting the effect of the MOF growth on the diffusion coefficients of the gas in the new composite polymer membranes. The results confirm that the growth of MOFs on polymer membranes can enhance the selectivity of the appropriately functionalized PIM-1, without a dramatic decrease of the permeability. PMID:28208658

  11. Synthesis of preliminary system designs for offshore oil and gas production

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Sin, Gürkan; Elmegaard, Brian

    2016-01-01

    The present work deals with the design of oil and gas platforms, with a particular focus on the developmentof integrated and intensified petroleum processing plants. It builds on a superstructure based approach that includes all the process steps, transformations and interconnections of relevance...... configurations and screening potentially novel solutions at early stage designs, with respect to technical, energetic and economic criteria....

  12. Tuning structural motifs and alloying of bulk immiscible Mo-Cu bimetallic nanoparticles by gas-phase synthesis

    Science.gov (United States)

    Krishnan, Gopi; Verheijen, Marcel A.; Ten Brink, Gert H.; Palasantzas, George; Kooi, Bart J.

    2013-05-01

    Nowadays bimetallic nanoparticles (NPs) have emerged as key materials for important modern applications in nanoplasmonics, catalysis, biodiagnostics, and nanomagnetics. Consequently the control of bimetallic structural motifs with specific shapes provides increasing functionality and selectivity for related applications. However, producing bimetallic NPs with well controlled structural motifs still remains a formidable challenge. Hence, we present here a general methodology for gas phase synthesis of bimetallic NPs with distinctively different structural motifs ranging at a single particle level from a fully mixed alloy to core-shell, to onion (multi-shell), and finally to a Janus/dumbbell, with the same overall particle composition. These concepts are illustrated for Mo-Cu NPs, where the precise control of the bimetallic NPs with various degrees of chemical ordering, including different shapes from spherical to cube, is achieved by tailoring the energy and thermal environment that the NPs experience during their production. The initial state of NP growth, either in the liquid or in the solid state phase, has important implications for the different structural motifs and shapes of synthesized NPs. Finally we demonstrate that we are able to tune the alloying regime, for the otherwise bulk immiscible Mo-Cu, by achieving an increase of the critical size, below which alloying occurs, closely up to an order of magnitude. It is discovered that the critical size of the NP alloy is not only affected by controlled tuning of the alloying temperature but also by the particle shape.Nowadays bimetallic nanoparticles (NPs) have emerged as key materials for important modern applications in nanoplasmonics, catalysis, biodiagnostics, and nanomagnetics. Consequently the control of bimetallic structural motifs with specific shapes provides increasing functionality and selectivity for related applications. However, producing bimetallic NPs with well controlled structural motifs still

  13. Chemical route to synthesis of mesoporous ZnO thin films and their liquefied petroleum gas sensor performance

    International Nuclear Information System (INIS)

    Dhawale, D.S.; Lokhande, C.D.

    2011-01-01

    Highlights: → Low temperature synthesis of mesoporous ZnO thin films by CBD method with urea containing bath. → Wurtzite crystal structure of mesoporous ZnO has been confirmed from the XRD study. → SEM images reveal the formation of hydrophobic mesoporous ZnO thin films. → Maximum LPG response of 52% has been achieved with high stability. - Abstract: In the present work, we report base free chemical bath deposition (CBD) of mesoporous zinc oxide (ZnO) thin films from urea containing bath for liquefied petroleum gas (LPG) sensor application. Mesoporous morphology with average pore size ∼2 μm and wurtzite crystal structure are confirmed from scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The surface of ZnO is hydrophobic with water contact angle 128 ± 1 o . Optical study reveals the presence of direct bad gap with energy 3.24 eV. The gas sensing study reveals the mesoporous ZnO is highly selective towards LPG as compared with CO 2 and maximum LPG response of 52% is achieved upon the exposure of 3900 ppm LPG at 573 K as well as good reproducibility and short response/recovery times.

  14. Synthesis and Characterization of a Novel Ammonia Gas Sensor Based on PANI-PVA Blend Thin Films

    Directory of Open Access Journals (Sweden)

    D. B. DUPARE

    2008-06-01

    Full Text Available The polyaniline - polyvinyl alcohol blend films were synthesized by oxidative polymerization using chemical synthesis route. The polyaniline films were synthesized using optimized concentration of monomer aniline, hydrochloric acid as a dopant using ammonium peroxy-disulphate as a oxidant and insulating addative matrix polyvinyl alcohol on glass substrate for development of ammonia sensor. The formation of PANI- PVA blend films show good uniform surface morphology at 10ºc temperature, maintained at constant temperature bath. The synthesized PANI-PVA blend thin films were characterized by analyzing UV-Visible and FTIR spectra. The SEM study ensures that the thin films are uniform and porous in nature. The I-V characterization shows ohmic behaviour and also determines conductivity of the films. The response time of PANI-PVA blend thin films show that excellent behavior for 50-800 ppm and higher range of ammonia gas. This study reveals that PANI-PVA blend thin films provide a polymer matrix with very good mechanical strength, environmental stability, uniformity in surface, porous morphology and high conductivity, which are suitable for ammonia gas sensing.

  15. Synthesis, Characterization and Gas Sensing Properties of Ag@α-Fe2O3 Core–Shell Nanocomposites

    Directory of Open Access Journals (Sweden)

    Ali Mirzaei

    2015-05-01

    Full Text Available Ag@α-Fe2O3 nanocomposite having a core–shell structure was synthesized by a two-step reduction-sol gel approach, including Ag nanoparticles synthesis by sodium borohydride as the reducing agent in a first step and the subsequent mixing with a Fe+3 sol for α-Fe2O3 coating. The synthesized Ag@α-Fe2O3 nanocomposite has been characterized by various techniques, such as SEM, TEM and UV-Vis spectroscopy. The electrical and gas sensing properties of the synthesized composite towards low concentrations of ethanol have been evaluated. The Ag@α-Fe2O3 nanocomposite showed better sensing characteristics than the pure α-Fe2O3. The peculiar hierarchical nano-architecture and the chemical and electronic sensitization effect of Ag nanoparticles in Ag@α-Fe2O3 sensors were postulated to play a key role in modulating gas-sensing properties in comparison to pristine α-Fe2O3 sensors.

  16. Toward industrial scale synthesis of ultrapure singlet nanoparticles with controllable sizes in a continuous gas-phase process

    Science.gov (United States)

    Feng, Jicheng; Biskos, George; Schmidt-Ott, Andreas

    2015-10-01

    Continuous gas-phase synthesis of nanoparticles is associated with rapid agglomeration, which can be a limiting factor for numerous applications. In this report, we challenge this paradigm by providing experimental evidence to support that gas-phase methods can be used to produce ultrapure non-agglomerated “singlet” nanoparticles having tunable sizes at room temperature. By controlling the temperature in the particle growth zone to guarantee complete coalescence of colliding entities, the size of singlets in principle can be regulated from that of single atoms to any desired value. We assess our results in the context of a simple analytical model to explore the dependence of singlet size on the operating conditions. Agreement of the model with experimental measurements shows that these methods can be effectively used for producing singlets that can be processed further by many alternative approaches. Combined with the capabilities of up-scaling and unlimited mixing that spark ablation enables, this study provides an easy-to-use concept for producing the key building blocks for low-cost industrial-scale nanofabrication of advanced materials.

  17. Synthesis of Titanium Oxycarbide from Titanium Slag by Methane-Containing Gas

    Science.gov (United States)

    Dang, Jie; Fatollahi-Fard, Farzin; Pistorius, Petrus Christiaan; Chou, Kuo-Chih

    2018-02-01

    In this study, reaction steps of a process for synthesis of titanium oxycarbide from titanium slag were demonstrated. This process involves the reduction of titanium slag by a methane-hydrogen-argon mixture at 1473 K (1200 °C) and the leaching of the reduced products by hydrofluoric acid near room temperature to remove the main impurity (Fe3Si). Some iron was formed by disproportionation of the main M3O5 phase before gaseous reduction started. Upon reduction, more iron formed first, followed by reduction of titanium dioxide to suboxides and eventually oxycarbide.

  18. Analytical control of the synthesis of the trithio and its precursors by gas chromatography

    International Nuclear Information System (INIS)

    Gonzalez Moreno, M. P.; Perez Garcia, M. M.; Angoso Marina, M.

    1979-01-01

    The synthesis of pesticide Trithio and its precursors has been controlled by G.L. selecting the best separation conditions and responses. The following columns have been used: 20% FFAP on chromo sorb W (a.w.) D.M.C.S. for organophosphate precursor glass column of 5 % Silicone SE-30 on chromo sorb G (a.w.) D.H.C.S. for S-(p-chlorophenyl-chloro methyl) and 12 % Silicone SE-30 modified with 8 % of Neopentyl-glicolsuccinate for Trithio. The relative retention times, retention indices and relative responses for. Trithio and its precursors have been calculated. (Author) 9 refs

  19. Design of generic coal conversion facilities: Production of oxygenates from synthesis gas---A technology review

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    This report concentrates on the production of oxygenates from coal via gasification and indirect liquefaction. At the present the majority of oxygenate synthesis programs are at laboratory scale. Exceptions include commercial and demonstration scale plants for methanol and higher alcohols production, and ethers such as MTBE. Research and development work has concentrated on elucidating the fundamental transport and kinetic limitations governing various reactor configurations. But of equal or greater importance has been investigations into the optimal catalyst composition and process conditions for the production of various oxygenates.

  20. A simple large-scale synthesis of mesoporous In_2O_3 for gas sensing applications

    International Nuclear Information System (INIS)

    Zhang, Su; Song, Peng; Yan, Huihui; Yang, Zhongxi; Wang, Qi

    2016-01-01

    Graphical abstract: Large-scale mesoporous In_2O_3 nanostructures for gas-sensing applications were successfully fabricated via a facile Lewis acid catalytic the furfural alcohol resin template route. - Highlights: • Mesoporous In_2O_3 nanostructures with high-yield have been successfully fabricated via a facile strategy. • The microstructure and formation mechanism of mesoporous In_2O_3 nanostructures were discussed based on the experimental results. • The as-prepared In_2O_3 samples exhibited high response, short response-recovery times and good selectivity to ethanol gas. - Abstract: In this paper, large-scale mesoporous In_2O_3 nanostructures were synthesized by a facile Lewis acid catalytic the furfural alcohol resin (FAR) template route for the high-yield. Their morphology and structure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal and thermogravimetry analysis (DSC-TG) and the Brunauer-Emmett-Teller (BET) approach. The as-obtained mesoporous In_2O_3 nanostructures possess excellent mesoporous and network structure, which increases the contact area with the gases, it is conducive for adsorption-desorption of gas on the surface of In_2O_3. The In_2O_3 particles and pores were both about 15 nm and very uniform. In gas-sensing measurements with target gases, the gas sensor based on mesoporous In_2O_3 nanostructures showed a good response, short response-recovery time, good selectivity and stability to ethanol. These properties are due to the large specific surface area of mesoporous structure. This synthetic method could use as a new design concept for functional mesoporous nanomaterials and for mass production.

  1. Multi-metallic oxides as catalysts for light alcohols and hydrocarbons from synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Miguel [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Diaz, L; Galindo, H de J; Dominguez, J. M; Salmon, Manuel [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    1999-08-01

    A series of Cu-Co-Cr oxides doped with alkaline metals (M), were prepared by the coprecipitation method with metal nitrates (Cu{sup I}I, CO{sup I}I, CR{sup I}II) and (M{sub 2})CO{sub 3} in aqueous solution. The calcined products were used as catalysts for the Fisher-Tropsch synthesis in a stainless-steel fixed bed microreactor. The material was characterized by x-ray diffraction, and the specific surface area, pore size and nitrogen adsorption-desorption properties were also determined. The alkaline metals favored the methanol synthesis and prevent the dehydration reactions whereas the hydrocarbon formation is independent to these metals. [Spanish] Una serie de oxidos Cu-Co-Cr soportados con metales alcalinos (M), fueron preparados por el metodo con nitratos metalicos (Cu{sup I}I, CO{sup I}I, CR{sup I}II) y (M{sub 2})CO{sub 3} en soluciones acuosas. Los productos calcinados fueron usados como catalizadores para la sintesis de Fisher-tropsch en la superficie fija de un microreactor de acero inoxidable. El material fue caracterizado por difraccion de rayos X y el area de superficie especifica, el tamano de poro y propiedades de absorcion-desorcion de nitrogeno fueron determinadas. Los metales alcalinos favorecieron la sintesis de metanol y previnieron las reacciones de deshidratacion, mientras que la formacion de hidrocarburos es independiente de estos metales.

  2. Zigzag GaN/Ga2O3 heterogeneous nanowires: Synthesis, optical and gas sensing properties

    Directory of Open Access Journals (Sweden)

    Li-Wei Chang

    2011-09-01

    Full Text Available Zigzag GaN/Ga2O3 heterogeneous nanowires (NWs were fabricated, and the optical properties and NO gas sensing ability of the NWs were investigated. We find that NWs are most effective at 850 °C at a switching process once every 10 min (on/off = 10 min per each with a mixture flow of NH3 and Ar. The red shift of the optical bandgap (0.66 eV is observed from the UV-vis spectrum as the GaN phase forms. The gas sensing characteristics of the developed sensor are significantly replaced to those of other types of NO sensors reported in literature.

  3. Synthesis of ZnO nanorods by spray pyrolysis for H2S gas sensor

    International Nuclear Information System (INIS)

    Shinde, S.D.; Patil, G.E.; Kajale, D.D.; Gaikwad, V.B.; Jain, G.H.

    2012-01-01

    Highlights: ► Hexagonal pillar shaped ZnO nanorods with different sizes have been successfully synthesized by spray pyrolysis technique. ► ZnO nanorods thin films showed much better sensitivity and stability than the conventional materials to H 2 S gas (100 ppm) at 50 °C. ► This ZnO thin film has potential in application of room temperature H 2 S gas sensing. - Abstract: Hexagonal pillar shaped ZnO nanorods with different sizes have been successfully synthesized by spray pyrolysis technique (SPT). The equal amount of methanol and water is used as a solvent to dissolve the AR grade Zinc acetate for precursor solution. This solution is sprayed on to the glass substrate heated at 350 °C. The films were characterized by ultra-violet spectroscopy (UV), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The deposition of thin films results in a layer comprising well-shaped hexagonal ZnO nanorods with diameter of 90–120 nm and length of up to 200 nm. The gas sensing properties of these films have been investigated for various interfering gases such as CO 2 , CO, ethanol, NH 3 and H 2 S, etc. at operating temperature from 30° (room temperature) to 450 °C. The results indicate that the ZnO nanorods thin films showed much better sensitivity and stability than the conventional materials to H 2 S gas (100 ppm) at 50 °C. The hexagonal pillar shaped ZnO nanorods can improve the sensitivity and selectivity of the sensors.

  4. Highly integrated CO2 capture and conversion: Direct synthesis of cyclic carbonates from industrial flue gas

    KAUST Repository

    Barthel, Alexander; Saih, Youssef; Gimenez, Michel; Pelletier, Jeremie; Kü hn, Fritz Elmar; D´ Elia, Valerio; Basset, Jean-Marie

    2016-01-01

    Robust and selective catalytic systems based on early transition metal halides (Y, Sc, Zr) and organic nucleophiles were found able to quantitatively capture CO2 from diluted streams via formation of hemicarbonate species and to convert it to cyclic organic carbonates under ambient conditions. This observation was exploited in the direct and selective chemical fixation of flue gas CO2 collected from an industrial exhaust, affording high degrees of CO2 capture and conversion.

  5. Highly integrated CO2 capture and conversion: Direct synthesis of cyclic carbonates from industrial flue gas

    KAUST Repository

    Barthel, Alexander

    2016-02-08

    Robust and selective catalytic systems based on early transition metal halides (Y, Sc, Zr) and organic nucleophiles were found able to quantitatively capture CO2 from diluted streams via formation of hemicarbonate species and to convert it to cyclic organic carbonates under ambient conditions. This observation was exploited in the direct and selective chemical fixation of flue gas CO2 collected from an industrial exhaust, affording high degrees of CO2 capture and conversion.

  6. Synthesis of diamond-like carbon via PECD using a streaming neutral gas injection hollow cathode

    International Nuclear Information System (INIS)

    Pacho, A.; Pares, E.; Ramos, H.; Mendenilla, A.; Malapit, G.

    2009-01-01

    A streaming neutral gas injection hollow cathode system was used to deposit diamond-like carbon films via plasma enhanced chemical vapor deposition on silicon and nickel-coated silicon substrates with acetylene and hydrogen as reactant gases. Samples were characterized using SEM and Raman spectroscopy. The work presented here aims to demonstrate the capability of the system to synthesize carbonaceous films and is starting point towards work on formation of carbon nanostructures. (author)

  7. Simple Synthesis of ZnCo2O4 Nanoparticles as Gas-sensing Materials

    Directory of Open Access Journals (Sweden)

    S. V. Bangale

    2011-11-01

    Full Text Available Semiconductive nanometer-size material ZnCo2O4 was synthesized by a solution combustion reaction of inorganic reagents of Zn(NO33. 6H2O, Co(NO33.6H2O and glycine as a fuel. The process was a convenient, environment friendly, inexpensive and efficient preparation method for the ZnCo2O4 nanomaterial. The synthesized materials were characterized by TG/DTA, XRD, EDX, SEM, and TEM. Conductance responses of the nanocrystalline ZnCo2O4 thick film were measured by exposing the film to reducing gases like Acetone, Ethanol, Ammonia (NH3, Hydrogen (H2, Hydrogen sulphide (H2S, Chlorine (Cl2 and Liquefied petroleum gas (LPG. It was found that the sensors exhibited various sensing responses to these gases at different operating temperature. Furthermore, the sensor exhibited a fast response and a good recovery. The results demonstrated that ZnCo2O4 can be used as a new type of gas-sensing material which has a high sensitivity and good selectivity to Liquefied petroleum gas (LPG at 100 ppm.

  8. Facile Synthesis, Microstructure, and Gas Sensing Properties of NdCoO3 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Lorenzo Gildo-Ortiz

    2017-01-01

    Full Text Available NdCoO3 nanoparticles were successfully synthesized by a simple, inexpensive, and reproducible solution method for gas sensing applications. Cobalt nitrate, neodymium nitrate, and ethylenediamine were used as precursors and distilled water as solvent. The solvent was evaporated later by means of noncontinuous microwave radiation at 290 W. The obtained precursor powders were calcined at 200, 500, 600, and 700°C in a standard atmosphere. The oxide crystallized in an orthorhombic crystal system with space group Pnma (62 and cell parameters a=5.33 Å, b=7.52 Å, and c=5.34 Å. The nanoparticles showed a diffusional growth to form a network-like structure and porous adsorption configuration. Pellets prepared from NdCoO3 were tested as gas sensors in atmospheres of carbon monoxide and propane at different temperatures. The oxide nanoparticles were clearly sensitive to changes in gas concentrations (0–300 ppm. The sensitivity increased with increasing concentration of the gases and operating temperatures (25, 100, 200, and 300°C.

  9. Synthesis and Crosslinking of Polyether-Based Main Chain Benzoxazine Polymers and Their Gas Separation Performance

    Directory of Open Access Journals (Sweden)

    Muntazim Munir Khan

    2018-02-01

    Full Text Available The poly(ethylene glycol-based benzoxazine polymers were synthesized via a polycondensation reaction between Bisphenol-A, paraformaldehyde, and poly(ether diamine/(Jeffamine®. The structures of the polymers were confirmed by proton nuclear magnetic resonance spectroscopy (1H-NMR, indicating the presence of a cyclic benzoxazine ring. The polymer solutions were casted on the glass plate and cross-linked via thermal treatment to produce tough and flexible films without using any external additives. Thermal properties and the crosslinking behaviour of these polymers were studied by thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. Single gas (H2, O2, N2, CO2, and CH4 transport properties of the crosslinked polymeric membranes were measured by the time-lag method. The crosslinked PEG-based polybenzoxazine membranes show improved selectivities for CO2/N2 and CO2/CH4 gas pairs. The good separation selectivities of these PEG-based polybenzoxazine materials suggest their utility as efficient thin film composite membranes for gas and liquid membrane separation technology.

  10. Synthesis and Gas Transport Properties of Hyperbranched Polyimide–Silica Hybrid/Composite Membranes

    Directory of Open Access Journals (Sweden)

    Masako Miki

    2013-12-01

    Full Text Available Hyperbranched polyimide–silica hybrids (HBPI–silica HBDs and hyperbranched polyimide–silica composites (HBPI–silica CPTs were prepared, and their general and gas transport properties were investigated to clarify the effect of silica sources and preparation methods. HBPI–silica HBDs and HBPI–silica CPTs were synthesized by two-step polymerization of A2 + B3 monomer system via polyamic acid as precursor, followed by hybridizing or blending silica sources. Silica components were incorporated by the sol-gel reaction with tetramethoxysilane (TMOS or the addition of colloidal silica. In HBPI-silica HBDs, the aggregation of silica components is controlled because of the high affinity of HBPI and silica caused by the formation of covalent bonds between HBPI and silica. Consequently, HBPI-silica HBDs had good film formability, transparency, and mechanical properties compared with HBPI-silica CPTs. HBPI-silica HBD and CPT membranes prepared via the sol-gel reaction with TMOS showed specific gas permeabilities and permselectivities for CO2/CH4 separation, that is, both CO2 permeability and CO2/CH4 selectivity increased with increasing silica content. This result suggests that gas transport can occur through a molecular sieving effect of the porous silica network derived from the sol-gel reaction and/or through the narrow interfacial region between the silica networks and the organic matrix.

  11. Synthesis and properties of ZnO nanorods as ethanol gas sensors

    International Nuclear Information System (INIS)

    Mirabbaszadeh, K; Mehrabian, M

    2012-01-01

    Uniform ZnO nanorods were synthesized via the sol-gel process under mild conditions in which different ZnO nanostructures have been prepared by changing the pH of growth solution. It was seen that the optimum nanorods were grown at pH 11.33. The prepared ZnO nanostructures and morphologies were characterized by x-ray diffraction and scanning electron microscopy measurements. The ZnO one-dimensional nanostructures were found to have a wurtzite hexagonal crystalline structure and grow along the [001] direction. The optimum nanorods were about 1 μm in length and less than 100 nm in diameter. The ZnO nanostructures have been tested for different concentrations and different operating temperatures for ethanol vapor in air and the surface resistance of the sensors has been evaluated as a function of different parameters. The gas sensor fabricated from ZnO nanorods grown in solution with a special pH exhibited good performance. The sensor response to 5000 ppm ethanol was up to about 2.5 at the operating temperature of 300 °C. The differences in gas-sensing performance between the sensors were analyzed based on the defects created in the nanorods during their fast growth. The correlations between material structures and the properties of the gas sensors are discussed.

  12. A simple large-scale synthesis of mesoporous In2O3 for gas sensing applications

    Science.gov (United States)

    Zhang, Su; Song, Peng; Yan, Huihui; Yang, Zhongxi; Wang, Qi

    2016-08-01

    In this paper, large-scale mesoporous In2O3 nanostructures were synthesized by a facile Lewis acid catalytic the furfural alcohol resin (FAR) template route for the high-yield. Their morphology and structure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal and thermogravimetry analysis (DSC-TG) and the Brunauer-Emmett-Teller (BET) approach. The as-obtained mesoporous In2O3 nanostructures possess excellent mesoporous and network structure, which increases the contact area with the gases, it is conducive for adsorption-desorption of gas on the surface of In2O3. The In2O3 particles and pores were both about 15 nm and very uniform. In gas-sensing measurements with target gases, the gas sensor based on mesoporous In2O3 nanostructures showed a good response, short response-recovery time, good selectivity and stability to ethanol. These properties are due to the large specific surface area of mesoporous structure. This synthetic method could use as a new design concept for functional mesoporous nanomaterials and for mass production.

  13. Nanostructured tin oxide films: Physical synthesis, characterization, and gas sensing properties.

    Science.gov (United States)

    Ingole, S M; Navale, S T; Navale, Y H; Bandgar, D K; Stadler, F J; Mane, R S; Ramgir, N S; Gupta, S K; Aswal, D K; Patil, V B

    2017-05-01

    Nanostructured tin oxide (SnO 2 ) films are synthesized using physical method i.e. thermal evaporation and are further characterized with X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy measurement techniques for confirming its structure and morphology. The chemiresistive properties of SnO 2 films are studied towards different oxidizing and reducing gases where these films have demonstrated considerable selectivity towards oxidizing nitrogen dioxide (NO 2 ) gas with a maximum response of 403% to 100ppm @200°C, and fast response and recovery times of 4s and 210s, respectively, than other test gases. In addition, SnO 2 films are enabling to detect as low as 1ppm NO 2 gas concentration @200°C with 23% response enhancement. Chemiresistive performances of SnO 2 films are carried out in the range of 1-100ppm and reported. Finally, plausible adsorption and desorption reaction mechanism of NO 2 gas molecules with SnO 2 film surface has been thoroughly discussed by means of an impedance spectroscopy analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. A synthesis of research on wood products and greenhouse gas impacts

    International Nuclear Information System (INIS)

    Sathre, R.; O'Connor, J.

    2008-11-01

    Existing scientific literature on the wood products industry was reviewed in an effort to summarize consensus findings, or range of findings, addressing the net life cycle greenhouse gas footprint of wood construction products. The report sought to clarify whether actively managing forests for wood production was better, worse or neutral for climate change than leaving the forest in its natural state. In addition, it sought to quantify the greenhouse gas emissions avoided per unit of wood substituted for non-wood materials. Forty-eight international studies were examined in terms of fossil energy used in wood manufacturing and compared alternatives, such as the avoidance of industrial process carbon emissions as with cement manufacturing; the storage of carbon in forests and forest products; the use of wood by-products as a biofuel replacement for fossil fuels; and carbon storage and emission due to forest products in landfills. The report presented a list of studies reviewed and individual summaries of study findings. A meta-analysis of displacement factors of wood product use was also presented. It was concluded from all of the studies reviewed, that the production of wood-based materials and products results in less greenhouse gas emission than the production of functionally comparable non-wood materials and products. 48 refs., 1 tab.

  15. Synthesis and evaluation of gas sensing properties of PANI based graphene oxide nanocomposites

    International Nuclear Information System (INIS)

    Gaikwad, Ganesh; Patil, Pritam; Patil, Devidas; Naik, Jitendra

    2017-01-01

    Highlights: • Developed GO, ZnO, PANI nanocomposites. • Evaluated for effect of GO addition on gas sensing performance. • Performed ammonia gas sensing at room temperature. • Obtained excellent recovery time of gas sensor. - Abstract: Polyaniline (PANI) nanofibers and Polyaniline/Graphene Oxide (PANI/GO), Polyaniline/Graphene Oxide/Zinc Oxide (PANI/GO/ZnO) nanocomposites were successfully prepared by nanoemulsion method. The synthesized nanofibers and nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Field emission scanning electron microscope (FE-SEM), has showed the evidence of interaction between PANI nanofibers, GO nanosheets and ZnO nanoparticles, respectively. PANI nanofibers and nanocomposites were used for the sensing of NH_3_, LPG, CO_2 and H_2S gases respectively at room temperature. It was observed that the PANI nanofibers and PANI/GO, PANI/GO/ZnO nanocomposites with different weight ratios of ZnO and GO had better selectivity and sensitivity towards NH_3 at room temperature. Best performance was shown by PANI/GO/ZnO nanocomposite response of 5.706 (10.3 times better response than PANI sensor) for 1000 ppm NH_3 at 80 ± 1 °C with the recovery time of 1 min 30 s only.

  16. Synthesis and evaluation of gas sensing properties of PANI based graphene oxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Gaikwad, Ganesh [Department of Chemical Engineering, University Institute of Chemical Technology, North Maharashtra University, Jalgaon 425001, Maharashtra (India); Patil, Pritam [SVMIT, College of Engineering, Bharuch 392001, Gujarat (India); Patil, Devidas [Bulk and Nanomaterials Research Laboratory, Rani Laxmibai Mahavidyalaya Parola, Jalgaon 425111, Maharashtra (India); Naik, Jitendra, E-mail: jbnaik@nmu.ac.in [Department of Chemical Engineering, University Institute of Chemical Technology, North Maharashtra University, Jalgaon 425001, Maharashtra (India)

    2017-04-15

    Highlights: • Developed GO, ZnO, PANI nanocomposites. • Evaluated for effect of GO addition on gas sensing performance. • Performed ammonia gas sensing at room temperature. • Obtained excellent recovery time of gas sensor. - Abstract: Polyaniline (PANI) nanofibers and Polyaniline/Graphene Oxide (PANI/GO), Polyaniline/Graphene Oxide/Zinc Oxide (PANI/GO/ZnO) nanocomposites were successfully prepared by nanoemulsion method. The synthesized nanofibers and nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Field emission scanning electron microscope (FE-SEM), has showed the evidence of interaction between PANI nanofibers, GO nanosheets and ZnO nanoparticles, respectively. PANI nanofibers and nanocomposites were used for the sensing of NH{sub 3,} LPG, CO{sub 2} and H{sub 2}S gases respectively at room temperature. It was observed that the PANI nanofibers and PANI/GO, PANI/GO/ZnO nanocomposites with different weight ratios of ZnO and GO had better selectivity and sensitivity towards NH{sub 3} at room temperature. Best performance was shown by PANI/GO/ZnO nanocomposite response of 5.706 (10.3 times better response than PANI sensor) for 1000 ppm NH{sub 3} at 80 ± 1 °C with the recovery time of 1 min 30 s only.

  17. Nitrogen gas emissions and nitrate leaching dynamics under different tillage practices based on data synthesis and process-based modeling

    Science.gov (United States)

    Huang, Y.; Ren, W.; Tao, B.; Zhu, X.

    2017-12-01

    Nitrogen losses from the agroecosystems have been of great concern to global changes due to the effects on global warming and water pollution in the form of nitrogen gas emissions (e.g., N2O) and mineral nitrogen leaching (e.g., NO3-), respectively. Conservation tillage, particularly no-tillage (NT), may enhance soil carbon sequestration, soil aggregation and moisture; therefore it has the potential of promoting N2O emissions and reducing NO3- leaching, comparing with conventional tillage (CT). However, associated processes are significantly affected by various factors, such as soil properties, climate, and crop types. How tillage management practices affect nitrogen transformations and fluxes is still far from clear, with inconsistent even opposite results from previous studies. To fill this knowledge gap, we quantitatively investigated gaseous and leaching nitrogen losses from NT and CT agroecosystems based on data synthesis and an improved process-based agroecosystem model. Our preliminary results suggest that NT management is more efficient in reducing NO3- leaching, and meanwhile it simultaneously increases N2O emissions by approximately 10% compared with CT. The effects of NT on N2O emissions and NO3- leaching are highly influenced by the placement of nitrogen fertilizer and are more pronounced in humid climate conditions. The effect of crop types is a less dominant factor in determining N2O and NO3- losses. Both our data synthesis and process-based modeling suggest that the enhanced carbon sequestration capacity from NT could be largely compromised by relevant NT-induced increases in N2O emissions. This study provides the comprehensive quantitative assessment of NT on the nitrogen emissions and leaching in agroecosystems. It provides scientific information for identifying proper management practices for ensuring food security and minimizing the adverse environmental impacts. The results also underscore the importance of suitable nitrogen management in the NT

  18. Gas phase synthesis of non-bundled, small diameter single-walled carbon nanotubes with near-armchair chiralities

    Energy Technology Data Exchange (ETDEWEB)

    Mustonen, K.; Laiho, P.; Kaskela, A.; Zhu, Z.; Reynaud, O.; Houbenov, N.; Tian, Y.; Jiang, H.; Kauppinen, E. I., E-mail: esko.kauppinen@aalto.fi [Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076 Aalto (Finland); Susi, T. [Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria); Nasibulin, A. G. [Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076 Aalto (Finland); Skolkovo Institute of Science and Technology, Nobel str. 3, 143026 (Russian Federation); Saint-Petersburg State Polytechnical University, 29 Polytechniheskaya st., St. Petersburg, 195251 (Russian Federation)

    2015-07-06

    We present a floating catalyst synthesis route for individual, i.e., non-bundled, small diameter single-walled carbon nanotubes (SWCNTs) with a narrow chiral angle distribution peaking at high chiralities near the armchair species. An ex situ spark discharge generator was used to form iron particles with geometric number mean diameters of 3–4 nm and fed into a laminar flow chemical vapour deposition reactor for the continuous synthesis of long and high-quality SWCNTs from ambient pressure carbon monoxide. The intensity ratio of G/D peaks in Raman spectra up to 48 and mean tube lengths up to 4 μm were observed. The chiral distributions, as directly determined by electron diffraction in the transmission electron microscope, clustered around the (n,m) indices (7,6), (8,6), (8,7), and (9,6), with up to 70% of tubes having chiral angles over 20°. The mean diameter of SWCNTs was reduced from 1.10 to 1.04 nm by decreasing the growth temperature from 880 to 750 °C, which simultaneously increased the fraction of semiconducting tubes from 67% to 80%. Limiting the nanotube gas phase number concentration to ∼10{sup 5 }cm{sup −3} prevented nanotube bundle formation that is due to collisions induced by Brownian diffusion. Up to 80% of 500 as-deposited tubes observed by atomic force and transmission electron microscopy were individual. Transparent conducting films deposited from these SWCNTs exhibited record low sheet resistances of 63 Ω/□ at 90% transparency for 550 nm light.

  19. Simonkolleite nano-platelets: Synthesis and temperature effect on hydrogen gas sensing properties

    Energy Technology Data Exchange (ETDEWEB)

    Sithole, J. [NANOAFNET, MRD-iThemba LABS, National Research Foundation,1 Old Faure road, Somerset West 7129 (South Africa); Dept. of Physics, University of Western Cape, Private Bag X 17, Belleville (South Africa); Ngom, B.D., E-mail: bdngom@tlabs.ac.za [NANOAFNET, MRD-iThemba LABS, National Research Foundation,1 Old Faure road, Somerset West 7129 (South Africa) and African Laser Centre, CSIR campus, P.O. Box 395, Pretoria (South Africa); Laboratoire de Photonique et de Nano-Fabrication, Groupe de Physique du Solide et Sciences des Materiaux, Departement de Physique Facultes des Sciences et Technique Universite Cheikh Anta Diop de Dakar, Dakar (Senegal); Khamlich, S. [NANOAFNET, MRD-iThemba LABS, National Research Foundation,1 Old Faure road, Somerset West 7129 (South Africa); African Laser Centre, CSIR campus, P.O. Box 395, Pretoria (South Africa); Manikanadan, E. [National Centre for Nano-Structured Materials (NCNSM), Council for Scientific and Industrial Research, Pretoria (South Africa); Manyala, N. [Department of Physics, SARCHI Chair in Carbon Technology and Materials, Institute of Applied Materials, University of Pretoria, Pretoria 0028 (South Africa); Saboungi, M.L. [Centre de Recherche sur la Matiere Divisee, CNRS-Orleans, Orleans (France); Knoessen, D. [Dept. of Physics, University of Western Cape, Private Bag X 17, Belleville (South Africa); Nemutudi, R.; Maaza, M. [NANOAFNET, MRD-iThemba LABS, National Research Foundation,1 Old Faure road, Somerset West 7129 (South Africa)

    2012-08-01

    In this work, the new refined mineral platelets-like morphology of simonkolleite based particles described by Shemetzer et al. (1985) were synthesized in zinc nitrate aqueous solution by a moderate solution process. The morphological and structural properties of the platelets-like Zn{sub 5}(OH){sub 8}Cl{sub 2}{center_dot}H{sub 2}O were characterized by scanning electron microscope energy dispersed X-ray spectroscopy, transmission electron microscope, powder X-ray diffraction and selected area electron diffraction as well as attenuated total reflection infrared spectroscopy. The morphology as well as the size in both basal and transversal directions of the simonkolleite Zn{sub 5}(OH){sub 8}Cl{sub 2}{center_dot}H{sub 2}O nano/micro crystals was found to be significantly depending on the specific concentration of 0.1 M of Zn{sup 2+}/Cl{sup -} ions in the precursor solution. The simonkolleite Zn{sub 5}(OH){sub 8}Cl{sub 2}{center_dot}H{sub 2}O nano-platelets revealed a significant and singular H{sub 2} gas sensing characteristics. The operating temperature was found to play a key role on the sensing properties of simonkolleite. The effect of temperature on the simonkolleite sample as a hydrogen gas sensor was studied by recording the change in resistivity of the film in presence of the test gas. The results on the sensitivity and response time as per comparison to earlier reported ZnO based sensors are indicated and discussed.

  20. Organometallic synthesis of ZnO nanoparticles for gas sensing: towards selectivity through nanoparticles morphology

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhikov, Andrey; Jońca, Justyna; Kahn, Myrtil; Fajerwerg, Katia [Laboratoire de Chimie de Coordination (LCC), CNRS (France); Chaudret, Bruno [Laboratoire de Physique et de Chimie de Nano-objets (LPCNO), INSA, UPS, CNRS (France); Chapelle, Audrey [Laboratoire d’Analyse et d’Architecture des Systèmes (LAAS), CNRS (France); Ménini, Philippe [Université Toulouse III, Paul Sabatier (France); Shim, Chang Hyun [Laboratoire d’Analyse et d’Architecture des Systèmes (LAAS), CNRS (France); Gaudon, Alain [Alpha M.O.S. SA (France); Fau, Pierre, E-mail: pierre.fau@lcc-toulouse.fr [Laboratoire de Chimie de Coordination (LCC), CNRS (France)

    2015-07-15

    ZnO nanoparticles (NP) with different morphologies such as nanorods (NR), isotropic NP, and cloud-like (CL) structures have been synthesized by an organometallic route. The prepared ZnO nanostructures have been deposited on miniaturized silicon gas sensor substrates by an inkjet method, and their responses to CO, C{sub 3}H{sub 8}, and NH{sub 3} gases have been studied at different operating temperatures (340–500 °C) and relative humidity of 50 %. It is noteworthy that the morphology of the nanostructure of the sensitive layer is maintained after thermal treatment. The morphology of ZnO NP significantly influences the sensor response level and their selectivity properties to reducing gases. Among the three different ZnO types, sensors prepared with NR show the highest response to both CO and C{sub 3}H{sub 8}. Sensors made of isotropic NP and CL structures show a lower but similar response to CO. From all investigated nanostructures, sensors made of CL structures show the weakest response to C{sub 3}H{sub 8}. With NH{sub 3} gas, no effect of the morphology of the ZnO sensitive layer has been evidenced. These different responses highlight the important role of the nanostructure of the ZnO sensitive layer and the nature of the target gas on the detection properties of the sensors. Graphical Abstract: Three different ZnO nanoparticles morphologies (cloud-like, dots, rods) have been employed as sensitive layers in chemoresistive sensors for the selective detection of CO, C{sub 3}H{sub 8} and NH{sub 3}.

  1. Synthesis Gas Demonstration Plant Program, Phase I. Commercial plant conceptual design and evaluation

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    This volume contains the trade-off study optimizing operating pressure (1200 psig was chosen), gas purification alternatives (Rectisol and Selexol processes were chosen). Coal preparation (wet grinding in a rod mill with trommel screen removal of oversize was recommended), air quality control (a 99.65% efficiency electrostatic precipitator and Wellman-Lord sulfur dioxide removal process were recommended), and for cooling tower optimization, a cooled water temperature of 83/sup 0/F was the optimum economic choice, with a hot water entering temperature of 118/sup 0/F. (LTN)

  2. Gas-phase synthesis of magnesium nanoparticles: A high-resolution transmission electron microscopy study

    International Nuclear Information System (INIS)

    Kooi, B. J.; Palasantzas, G.; De Hosson, J. Th. M.

    2006-01-01

    Magnesium nanoparticles with size above 10 nm, prepared by gas-phase syntheses, were investigated by high-resolution transmission electron microscopy. The dominant particle shape is a hexagonal prism terminated by Mg(0002) and Mg(1010) facets. Oxidation of Mg yields a MgO shell (∼3 nm thick), which has an orientation relation with the Mg. Inhomogeneous facet oxidation influences their growth kinetics resulting in a relatively broad size and shape distribution. Faceted voids between Mg and MgO shells indicate a fast outward diffusion of Mg and vacancy rearrangement into voids. The faceting of polar (220) planes is assisted by electron irradiation

  3. Iron catalyst for preparation of polymethylene from synthesis gas and method for producing the catalyst

    Science.gov (United States)

    Sapienza, R.S.; Slegeir, W.A.

    1990-05-15

    This invention relates to a process for synthesizing hydrocarbons; more particularly, the invention relates to a process for synthesizing long-chain hydrocarbons known as polymethylene from carbon monoxide and hydrogen or from carbon monoxide and water or mixtures thereof in the presence of a catalyst comprising iron and platinum or palladium or mixtures thereof which may be supported on a solid material, preferably an inorganic refractory oxide. This process may be used to convert a carbon monoxide containing gas to a product which could substitute for high density polyethylene.

  4. Gas production, microbial synthesis by radio phosphorus and digestibility of babassu and mofumbo in sheep diets

    International Nuclear Information System (INIS)

    Abdalla Filho, Adibe Luiz

    2015-01-01

    When food shortages in natural pastures is committed to animal nutrition, small ruminants can incorporate into their diets the leaves of other plants, such as trees and shrubs, many of them rich in secondary metabolites such as tannins and which still lack of studies about its effect on animal productivity. In order to verify the possibility of using leaves of Orbignya phalerata (Babassu) and Combretum leprosum (Mofumbo) in feed and to evaluate the effect of their inclusion in the sheep production system, two studies were conducted at the Animal Nutrition Laboratory of Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Piracicaba (LANA/CENA-USP). The first study evaluated the performance variables, biochemical and hematological parameters and also determined the microbial protein synthesis, nutrient apparent digestibility and enteric production of methane (CH4). The second study assessed the carcass characteristics, fatty acid profile and meat color of male sheep used in the first study. The experimental treatments were diets with forages to concentrate rate of 50:50, drawn up on the basis of using the leaves of the experimental plants replacing 30% of the Cynodon dactylon (Tifton-85) hay, resulting in three treatments: Control (no hay replacement), Babassu and Mofumbo. In the first study, there were used 24 Santa Ines sheep, in a randomized experimental design with eight repetitions for each treatment and 48 days of trial period. Also during this period, an in vitro microbial protein synthesis was performed using the radio phosphorus using five different inoculum of each studied treatment. After this period, for nine days, six animals from each treatment were allocated in metabolic cages for determining the nutrient apparent digestibility, microbial protein synthesis and nitrogen balance. Simultaneously it was quantified the enteric CH4 production in vivo. The Control group showed greater (P < 0.05) apparent digestibility of acid detergent fiber

  5. Prediction of vapour-liquid equilibria for the kinetic study of processes based on synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Di Serio, M.; Tesser, R.; Cozzolino, M.; Santacesaria, E. [Naples Univ., Napoli (Italy). Dept. of Chemistry

    2006-07-01

    Syngas is normally used in the production of a broad range of chemicals and fuels. In many of these processes multiphase reactors, gas-liquid or gas-liquid-solid are used. Kinetic studies in multiphase systems are often complicated by the non-ideal behaviour of reagents and/or products that are consistently partitioned between the liquid and the vapour phase. Moreover, as often kinetic data are collected in batch conditions for the liquid phase, activity coefficients of the partitioned components can consistently change during the time as a consequence of changing the composition of the reaction mixture. Therefore, it is necessary, in these cases, to known the vapor-liquid equilibria (VLE) in order to collect and to interpret correctly the kinetic data. The description of phase equilibria, at high pressures, is usually performed by means of an EOS (Equation of State) allowing the calculation of fugacity coefficients, for each component, in both phases and determining the partition coefficients but the EOS approach involves the experimental determination of the interaction parameters for all the possible binary system of the mixture. For multicomponent mixtures a complete experimental determination of vapourliquid equilibria is very hard, also considering the high pressure and temperatures used. Some predictive group contribution methods have been recently developed. In this paper, we will describe in detail the application of these methods to the methanol homologation, as an example, with the scope of determining more reliable kinetic parameters for this reaction. (orig.)

  6. Effect of carrier gas composition on transferred arc metal nanoparticle synthesis

    International Nuclear Information System (INIS)

    Stein, Matthias; Kiesler, Dennis; Kruis, Frank Einar

    2013-01-01

    Metal nanoparticles are used in a great number of applications; an effective and economical production scaling-up is hence desirable. A simple and cost-effective transferred arc process is developed, which produces pure metal (Zn, Cu, and Ag) nanoparticles with high production rates, while allowing fast optimization based on energy efficiency. Different carrier gas compositions, as well as the electrode arrangements and the power input are investigated to improve the production and its efficiency and to understand the arc production behavior. The production rates are determined by a novel process monitoring method, which combines an online microbalance method with a scanning mobility particle sizer for fast production rate and size distribution measurement. Particle characterization is performed via scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction measurements. It is found that the carrier gas composition has the largest impact on the particle production rate and can increase it with orders of magnitude. This appears to be not only a result of the increased heat flux and melt temperature but also of the formation of tiny nitrogen (hydrogen) bubbles in the molten feedstock, which impacts feedstock evaporation significantly in bi-atomic gases. A production rate of sub 200 nm particles from 20 up to 2,500 mg/h has been realized for the different metals. In this production range, specific power consumptions as low as 0.08 kWh/g have been reached.

  7. Synthesis of Nanoparticle Model Systems for Sustainable Catalysis by Gas Aggregation

    DEFF Research Database (Denmark)

    Bodin, Anders

    The overall goal of this thesis is to develop better catalysts for chemical reactions used in sustainable energy storage and environmental protection. Specifically, the thesis presents research on well-defined catalyst model systems of nanoparticles synthesized by magnetron sputtering, gas......−Mo−S Nanoparticles by Reactive Gas Aggregation: In this project, a method was developed for synthesizing in-flight sulfided Ni-Mo-S nanoparticles by aggregation of sputtered metal from a Mo75Ni25 target in a reactive atmosphere of Ar and H2S. The resulting particles are undersulfided with a stoichiometry of Mo0.8Ni0...... keys to developing better catalysts for energy-storage by electrolysis of CO2 is to understand the principles behind electroreduction of the reaction intermediate CO. This study reports the discovery of a high, transient production of methane at the onset of electroreduction of CO on mass-selected copper...

  8. Hydrogen or synthesis gas production via the partial oxidation of methane over supported nickel-cobalt catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Alaric C.W. [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Chen, Luwei; Lin, Jianyi [Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Kee Leong, Weng [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Johnson, Brian F.G.; Khimyak, Tetyana [University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge, UK CB2 1EW (United Kingdom)

    2007-05-15

    Activity, selectivity, and coking-resistance of a series of Ni{sub x}Co{sub y} (where x,y are the respective metal loadings of 0, 1, 2 or 3 wt.%; x+y=3) bimetallic catalysts supported on CaAl{sub 2}O{sub 4}/Al{sub 2}O{sub 3} have been studied for hydrogen/synthesis gas production via the catalytic partial oxidation (CPO) of methane. Catalysts were characterized by temperature programmed reduction (TPR), transmission electron microscopy (TEM) and X-ray fluorescence multi-element analysis (XRF). Their activity for the partial oxidation of methane to hydrogen and carbon monoxide (at 1 bar, gas hourly space velocity (GHSV) of 144,000cm{sup 3}g{sup -1}h{sup -1} and CH{sub 4}/O{sub 2} molar ratio of 2) was investigated, and coke deposited on the spent catalysts was studied by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and thermogravimetric analysis (TGA). The activity was found to decrease in the order of Ni{sub 2}Co>Ni{sub 3}>NiCo{sub 2}>>Co{sub 3}, while CO and H{sub 2} selectivities were found to be in the order ofNi{sub 2}Co>Ni{sub 3}{approx}NiCo{sub 2}>Co{sub 3}. Ni{sub 2}Co is also shown to be more resistant to coking as compared to Ni{sub 3}, which is a current catalyst of choice. Results show that not only does Ni{sub 2}Co have the highest activity and selectivity among all the catalysts tested, it is also relatively resistant to coking. This finding would be helpful for catalyst design to achieve high coking resistivity catalysts for hydrogen production from CPO of methane. (author)

  9. Synthetic crystalline ferroborosilicate compositions, the preparation thereof and their use in the conversion of synthesis gas to low molecular weight hydrocarbons

    International Nuclear Information System (INIS)

    Hinnenkamp, J.A.; Walatka, V.V.

    1987-01-01

    A method for the conversion of synthesis gas is described comprising: contacting synthesis gas which comprises hydrogen and carbon monoxide with a catalytically effective amount of a crystalline ferroborosilicate composition, under conversion conditions effective to provide ethane selectivity of at least 40%. The borosilicate composition is represented in terms of mole ratios as follows: (0.2 to 15) M/sub 2/m/O:(0.2 to 10) Z/sub 2/ O /sub 3/: (5 to 1000) SiO/sub 2/: Fe/sub 2/n/O: (0 to 2000) H/sub 2/O wherein M comprises a cation of a quaternary ammonium, metal, ammonium, hydrogen and mixtures thereof, m is the valence of the cation, n is the valence of the iron cation, and Z is boron. The composition contains ion-exchanged palladium or palladium impregnated onto the composition

  10. Flame synthesis of carbon nano onions using liquefied petroleum gas without catalyst

    International Nuclear Information System (INIS)

    Dhand, Vivek; Prasad, J. Sarada; Rao, M. Venkateswara; Bharadwaj, S.; Anjaneyulu, Y.; Jain, Pawan Kumar

    2013-01-01

    Densely agglomerated, high specific surface area carbon nano onions with diameter of 30–40 nm have been synthesized. Liquefied petroleum gas and air mixtures produced carbon nano onions in diffusion flames without catalyst. The optimized oxidant to fuel ratio which produces carbon nano onions has been found to be 0.1 slpm/slpm. The experiment yielded 70% pure carbon nano onions with a rate of 5 g/h. X-ray diffraction, high-resolution electron microscopy and Raman spectrum reveal the densely packed sp 2 hybridized carbon with (002) semi-crystalline hexagonal graphite reflection. The carbon nano onions are thermally stable up to 600 °C. - Highlights: ►Flame synthesized carbon nano onions with 30–40 nm diameters. ►LPG/air, diffusion type flame used in absence of catalyst to produce nano onions. ►Carbon nano onion production rate is 5 g/hr and with 70% purity.

  11. Synthesis of carbon nanotubes by CCVD of natural gas using hydrotreating catalysts

    Directory of Open Access Journals (Sweden)

    Ahmed E. Awadallah

    2012-12-01

    Full Text Available Carbon nanotubes have been successfully synthesized using the catalytic chemical vapor deposition (CCVD technique over typical refining hydrotreating catalysts (hydrodesulfurization and hydrodenitrogenation containing Ni–Mo and Co–Mo supported on Al2O3 catalysts at 700°C in a fixed bed horizontal reactor using natural gas as a carbon source. The catalysts and the as-grown CNTs were characterized by transmission electron microscopy, HRTEM, X-ray diffraction patterns, EDX and TGA–DTG. The obtained data clarified that the Ni–Mo catalyst gives higher yield, higher purity and selectivity for CNTs compared to Co–Mo catalyst. XRD, TEM and TGA reveal also that the Ni–Mo catalyst produces mostly CNTs with different diameters whereas the Co–Mo catalyst produces largely amorphous carbon.

  12. Synthesis, magnetic and ethanol gas sensing properties of semiconducting magnetite nanoparticles

    Science.gov (United States)

    Al-Ghamdi, Ahmed A.; Al-Hazmi, Faten; Al-Tuwirqi, R. M.; Alnowaiser, F.; Al-Hartomy, Omar A.; El-Tantawy, Farid; Yakuphanoglu, F.

    2013-05-01

    The superparamagnetic magnetite (Fe3O4) nanoparticles with an average size of 7 nm were synthesized using a rapid and facile microwave hydrothermal technique. The structure of the magnetite nanoparticles was characterized by X-ray diffraction (X-ray), field effect scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM). The prepared Fe3O4 was shown to have a cubic phase of pure magnetite. Magnetization hysteresis loop shows that the synthesized magnetite exhibits no hysteretic features with a superparamagnetic behavior. The ethanol gas sensing properties of the synthesized magnetite were investigated, and it was found that the responsibility time is less than 10 s with good reproducibility for ethanol sensor. Accordingly, it is evaluated that the magnetite nanoparticles can be effectively used as a solid state ethanol sensor in industrial commercial product applications.

  13. Ferrite thin films: Synthesis, characterization and gas sensing properties towards LPG

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Pratibha; Godbole, R.V. [Department of Physics, Abasaheb Garware College, Karve Road, Pune 411 004 (India); Phase, D.M. [UGC-DAE CSR Centre, Indore (India); Chikate, R.C. [Department of Chemistry, Abasaheb Garware College, Karve Road, Pune 411 004 (India); Bhagwat, Sunita, E-mail: smb.agc@gmail.com [Department of Physics, Abasaheb Garware College, Karve Road, Pune 411 004 (India)

    2015-01-15

    Nanocrystalline (Co, Cu, Ni, Zn) ferrite thin films have been deposited onto the Si (100) and alumina substrates by spray pyrolysis deposition technique. Respective metal chlorides and iron chloride were used as precursors. The structural properties of (Co, Cu, Ni, Zn) ferrite thin films were investigated by X-ray diffraction (XRD) technique which confirms polycrystalline nature and single phase spinel structure. The surface morphology was studied using scanning electron microscopy (SEM) which reveals spherical morphology for these films except NiFe{sub 2}O{sub 4} films that exhibit petal like structure. The optical transmittance and reflectance measurements were recorded using a double beam spectrophotometer. The optical studies reveal that the transition is direct band gap energy. The VSM analyzes reveal the predominant ferrimagnetic nature for CuFe{sub 2}O{sub 4} films. The gas sensing properties towards Liquid Petroleum Gas (LPG) revealed that ZnFe{sub 2}O{sub 4} films are sensitive at lower temperature while NiFe{sub 2}O{sub 4} films show steep rise at higher temperature. - Highlights: • (Co, Cu, Ni, Zn) ferrite thin films are synthesized by simple spray pyrolysis technique. • Homogenization of substituent within ferrite structure. • CuFe{sub 2}O{sub 4} film exhibits predominantly ferrimagnetic nature. • LPG sensing at lower temperature for ZnFe{sub 2}O{sub 4} film. • High sensitivity for NiFe{sub 2}O{sub 4} film at higher temperature due to defects created in the structure.

  14. Development of Ni-Based Catalysts Derived from Hydrotalcite-Like Compounds Precursors for Synthesis Gas Production via Methane or Ethanol Reforming

    OpenAIRE

    Ya-Li Du; Xu Wu; Qiang Cheng; Yan-Li Huang; Wei Huang

    2017-01-01

    As a favorably clean fuel, syngas (synthesis gas) production has been the focus of concern in past decades. Substantial literatures reported the syngas production by various catalytic reforming reactions particularly in methane or ethanol reforming. Among the developed catalysts in these reforming processes, Ni-based catalysts from hydrotalcite-like compounds (HTLcs) precursors have drawn considerable attention for their preferable structural traits. This review covers the recent literature r...

  15. Synthesis and Characterization of Nanostructured ZnO Thick Film Gas Sensors Prepared by Screen Printing Method

    Directory of Open Access Journals (Sweden)

    R. Y. BORSE

    2010-12-01

    Full Text Available Nanosized ZnO was prepared by self propagating solution combustion synthesis method. The synthesized ZnO thick films were deposited on alumina substrate by using standard screen printing technique and fired at 700 0C. The films were characterized by X-ray diffractometer (XRD, Scanning Electron Microscopy (SEM and energy dispersive analysis of X-ray (EDAX. The electrical behaviors of ZnO thick films were investigated. From XRD spectra it is revealed that ZnO films are polycrystalline in nature. The average grain size of 87.44 nm has been estimated for the film fired at 700 0C using Scherrer’s formula. EDAX clearly shows the peaks corresponding to Zn and O element which confirms the successful growth of ZnO films. Gas sensing study for these samples shows high sensitivity and selectivity towards NO2 at all operating temperatures. The resistivity, TCR and activation energy of the ZnO films have been evaluated and discussed.

  16. Fast and simple microwave synthesis of TiO2/Au nanoparticles for gas-phase photocatalytic hydrogen generation

    Science.gov (United States)

    May-Masnou, Anna; Soler, Lluís; Torras, Miquel; Salles, Pol; Llorca, Jordi; Roig, Anna

    2018-04-01

    The fabrication of small anatase titanium dioxide (TiO2) nanoparticles (NPs) attached to larger anisotropic gold (Au) morphologies by a very fast and simple two-step microwave-assisted synthesis is presented. The TiO2/Au NPs are synthesized using polyvinylpyrrolidone (PVP) as reducing, capping and stabilizing agent through a polyol approach. To optimize the contact between the titania and the gold and facilitate electron transfer, the PVP is removed by calcination at mild temperatures. The nanocatalysts activity is then evaluated in the photocatalytic production of hydrogen from water/ethanol mixtures in gas-phase at ambient temperature. A maximum value of 5.3 mmol·gcat-1·h-1 (7.4 mmol·gTiO2-1·h-1) of hydrogen is recorded for the system with larger gold particles at an optimum calcination temperature of 450 °C. Herein we demonstrate that TiO2-based photocatalysts with high Au loading and large Au particle size (≈ 50 nm) NPs have photocatalytic activity.

  17. Low-temperature synthesis of 2D MoS2 on a plastic substrate for a flexible gas sensor.

    Science.gov (United States)

    Zhao, Yuxi; Song, Jeong-Gyu; Ryu, Gyeong Hee; Ko, Kyung Yong; Woo, Whang Je; Kim, Youngjun; Kim, Donghyun; Lim, Jun Hyung; Lee, Sunhee; Lee, Zonghoon; Park, Jusang; Kim, Hyungjun

    2018-05-08

    The efficient synthesis of two-dimensional molybdenum disulfide (2D MoS2) at low temperatures is essential for use in flexible devices. In this study, 2D MoS2 was grown directly at a low temperature of 200 °C on both hard (SiO2) and soft substrates (polyimide (PI)) using chemical vapor deposition (CVD) with Mo(CO)6 and H2S. We investigated the effect of the growth temperature and Mo concentration on the layered growth by Raman spectroscopy and microscopy. 2D MoS2 was grown by using low Mo concentration at a low temperature. Through optical microscopy, Raman spectroscopy, X-ray photoemission spectroscopy, photoluminescence, and transmission electron microscopy measurements, MoS2 produced by low-temperature CVD was determined to possess a layered structure with good uniformity, stoichiometry, and a controllable number of layers. Furthermore, we demonstrated the realization of a 2D MoS2-based flexible gas sensor on a PI substrate without any transfer processes, with competitive sensor performance and mechanical durability at room temperature. This fabrication process has potential for burgeoning flexible and wearable nanotechnology applications.

  18. Hydrogen Gas Is Involved in Auxin-Induced Lateral Root Formation by Modulating Nitric Oxide Synthesis

    Directory of Open Access Journals (Sweden)

    Zeyu Cao

    2017-10-01

    Full Text Available Metabolism of molecular hydrogen (H2 in bacteria and algae has been widely studied, and it has attracted increasing attention in the context of animals and plants. However, the role of endogenous H2 in lateral root (LR formation is still unclear. Here, our results showed that H2-induced lateral root formation is a universal event. Naphthalene-1-acetic acid (NAA; the auxin analog was able to trigger endogenous H2 production in tomato seedlings, and a contrasting response was observed in the presence of N-1-naphthyphthalamic acid (NPA, an auxin transport inhibitor. NPA-triggered the inhibition of H2 production and thereafter lateral root development was rescued by exogenously applied H2. Detection of endogenous nitric oxide (NO by the specific probe 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate (DAF-FM DA and electron paramagnetic resonance (EPR analyses revealed that the NO level was increased in both NAA- and H2-treated tomato seedlings. Furthermore, NO production and thereafter LR formation induced by auxin and H2 were prevented by 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO; a specific scavenger of NO and the inhibitor of nitrate reductase (NR; an important NO synthetic enzyme. Molecular evidence confirmed that some representative NO-targeted cell cycle regulatory genes were also induced by H2, but was impaired by the removal of endogenous NO. Genetic evidence suggested that in the presence of H2, Arabidopsis mutants nia2 (in particular and nia1 (two nitrate reductases (NR-defective mutants exhibited defects in lateral root length. Together, these results demonstrated that auxin-induced H2 production was associated with lateral root formation, at least partially via a NR-dependent NO synthesis.

  19. Characterization of coal-derived hydrocarbons and source-rock potential of coal beds, San Juan Basin, New Mexico and Colorado, U.S.A.

    Science.gov (United States)

    Rice, D.D.; Clayton, J.L.; Pawlewicz, M.J.

    1989-01-01

    Coal beds are considered to be a major source of nonassociated gas in the Rocky Mountain basins of the United States. In the San Juan basin of northwestern New Mexico and southwestern Colorado, significant quantities of natural gas are being produced from coal beds of the Upper Cretaceous Fruitland Formation and from adjacent sandstone reservoirs. Analysis of gas samples from the various gas-producing intervals provided a means of determining their origin and of evaluating coal beds as source rocks. The rank of coal beds in the Fruitland Formation in the central part of the San Juan basin, where major gas production occurs, increases to the northeast and ranges from high-volatile B bituminous coal to medium-volatile bituminous coal (Rm values range from 0.70 to 1.45%). On the basis of chemical, isotopic and coal-rank data, the gases are interpreted to be thermogenic. Gases from the coal beds show little isotopic variation (??13C1 values range -43.6 to -40.5 ppt), are chemically dry (C1/C1-5 values are > 0.99), and contain significant amounts of CO2 (as much as 6%). These gases are interpreted to have resulted from devolatilization of the humic-type bituminous coal that is composed mainly of vitrinite. The primary products of this process are CH4, CO2 and H2O. The coal-generated, methane-rich gas is usually contained in the coal beds of the Fruitland Formation, and has not been expelled and has not migrated into the adjacent sandstone reservoirs. In addition, the coal-bed reservoirs produce a distinctive bicarbonate-type connate water and have higher reservoir pressures than adjacent sandstones. The combination of these factors indicates that coal beds are a closed reservoir system created by the gases, waters, and associated pressures in the micropore coal structure. In contrast, gases produced from overlying sandstones in the Fruitland Formation and underlying Pictured Cliffs Sandstone have a wider range of isotopic values (??13C1 values range from -43.5 to -38

  20. Dry re-forming of methane to synthesis gas over lignite semicokes catalyst at high pressure

    Directory of Open Access Journals (Sweden)

    Fengbo Guo

    2016-11-01

    Full Text Available Dry re-forming of methane has been carried out in a high temperature–pressure reactor at different pressures, using Hongce lignite semicokes catalyst. The results show that CH4 and CO2 conversions are decreased as the reaction pressure increased, but both of them kept basically stable when the reaction pressure is between 0.3 and 1 MPa. The comparison shows that the effects of the temperature and the flow of reactant gas on dry re-forming of methane are consistent with between high pressure and atmospheric pressure. The ratio of CO/H2 decreased as the ratio of CH4/CO2 increased, yet the value of CO/H2 is always more than 1 at different pressures. Hongce lignite semicokes catalyst is characterized by FTIR, XRD, SEM and BET, and the analysis results reveled that the physical specific adsorption peak of CO2 at 2350 cm−1 is strengthened significantly at different pressures, the micropore area and volume of Hongce lignite semicokes reduced form 40.2 m2  g−1 and 0.019 cm3  g−1 to 34.9 m2  g−1 and 0.017 cm3  g−1, respectively. Hongce lignite semicokes catalyst exhibited better activity and stability within 0.3–1 MPa range.

  1. Synthesis and gas transport properties of hydroxyl-functionalized polyimides with intrinsic microporosity

    KAUST Repository

    Ma, Xiaohua

    2012-05-08

    A newly designed diamine monomer, 3,3,3′,3′-tetramethyl-1, 1′-spirobisindane-5,5′-diamino-6,6′-diol, was successfully used to synthesize two types of polyimides for membrane-based gas separation applications. The novel polymers integrate significant microporosity and polar hydroxyl groups, showing the combined features of polymers of intrinsic microporosity (PIMs) and functional polyimides (PIs). They possess high thermal stability, good solubility, and easy processability for membrane fabrication; the resulting membranes exhibit good permeability owing to the intrinsic microporosity introduced by the highly contorted PIM segments as well as high CO 2/CH 4 selectivity that arises from the hydroxyl groups. The membranes show CO 2/CH 4 selectivities of >20 when tested with a 1:1 CO 2/CH 4 mixture for feed pressures up to 50 bar. In addition, the incorporation of hydroxyl groups and microporosity in the polymers enhances their affinity to water, leading to remarkable water sorption capacities of up to 22 wt % at 35 °C and 95% relative humidity. © 2012 American Chemical Society.

  2. A porous cadmium(II) framework. Synthesis, crystal structure, gas adsorption, and fluorescence sensing properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Pingping [College of Sciences, Agricultural University of Hebei, Baoding (China)

    2017-05-18

    The Cd{sup II} compound, namely [Cd(Tppa)(SO{sub 4})(H{sub 2}O)]{sub n} (1) [Tppa = tris(4-(pyridyl)phenyl) amine], was synthesized by the reaction of CdSO{sub 4}.8H{sub 2}O and Tppa under solvothermal conditions. Single crystal X-ray diffraction analysis revealed that compound 1 features a 3D porous framework based on 1D inorganic -[Cd-SO{sub 4}-Cd]{sub n}- chains. Topological analysis reveals that compound 1 represents a trinodal (3,4,6)-connected topological network with the point symbol of {6.7"2}{sub 2}{6"4.7.10}{6"4.7"5.8"4.10"2}. Gas adsorption properties investigations indicate that compound 1 exhibits moderate adsorption capacities for light hydrocarbons at room temperature. Luminescence property studies revealed that this Cd{sup II} compound exhibits high fluorescence sensitivity for sensing of CS{sub 2} molecule. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. A nanostructured composite based on polyaniline and gold nanoparticles: synthesis and gas sensing properties

    International Nuclear Information System (INIS)

    Venditti, Iole; Fratoddi, Ilaria; Russo, Maria Vittoria; Bearzotti, Andrea

    2013-01-01

    Nanostructured composite materials based on polyaniline (PANI) and gold nanoparticles have been prepared by means of an osmosis based method. Several morphologies have been obtained for the pristine nanoPANI and for nanoPANI–Au composite, ranging from amorphous to sponge-like and spherical shapes. On the basis of this morphological investigation, different materials with high surface area have been selected and tested as chemical interactive materials for room temperature gas and vapor sensing. The resistive sensor devices have been exposed to different vapor organic compounds (VOCs) of interest in the fields of environmental monitoring and biomedical applications, such as toluene, acetic acid, ethanol, methanol, acetonitrile, water, ammonia and nitrogen dioxide. The effect of doping with H 2 SO 4 has been studied for both nanoPANI and nanoPANI–Au samples. In particular, nanoPANI–Au showed sensitivity to ammonia (up to 10 ppm) higher than that to other VOCs or interfering analytes. The facile preparation method and the improved properties achieved for the polyaniline–gold composite materials are significant in the nanomaterials field and have promise for applications in ammonia vapor monitoring. (paper)

  4. Flame synthesis of carbon nano onions using liquefied petroleum gas without catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Dhand, Vivek, E-mail: vivekdhand2012@gmail.com [Centre for Knowledge Management of Nanoscience and Technology, 12-5-32/8, Vijayapuri Colony, Tarnaka, Secunderabad-500 017, A.P (India); Prasad, J. Sarada; Rao, M. Venkateswara [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad 500 085 (India); Bharadwaj, S. [Department of Physics, CVR College of Engineering and Osmania University, Hyderabad 501510, A.P (India); Anjaneyulu, Y. [TLGVRC, Jackson State University, JSU Box 18739, Jackson, MS 39217-0939 (United States); Jain, Pawan Kumar [International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Balapur PO, Hyderabad 500005, Andhra Pradesh (India)

    2013-03-01

    Densely agglomerated, high specific surface area carbon nano onions with diameter of 30-40 nm have been synthesized. Liquefied petroleum gas and air mixtures produced carbon nano onions in diffusion flames without catalyst. The optimized oxidant to fuel ratio which produces carbon nano onions has been found to be 0.1 slpm/slpm. The experiment yielded 70% pure carbon nano onions with a rate of 5 g/h. X-ray diffraction, high-resolution electron microscopy and Raman spectrum reveal the densely packed sp{sup 2} hybridized carbon with (002) semi-crystalline hexagonal graphite reflection. The carbon nano onions are thermally stable up to 600 Degree-Sign C. - Highlights: Black-Right-Pointing-Pointer Flame synthesized carbon nano onions with 30-40 nm diameters. Black-Right-Pointing-Pointer LPG/air, diffusion type flame used in absence of catalyst to produce nano onions. Black-Right-Pointing-Pointer Carbon nano onion production rate is 5 g/hr and with 70% purity.

  5. Dual Layer Monolith ATR of Pyrolysis Oil for Distributed Synthesis Gas Production

    Energy Technology Data Exchange (ETDEWEB)

    Lawal, Adeniyi [Stevens Institute of Technology, Castle Point Hoboken NJ 07030

    2012-09-29

    We have successfully demonstrated a novel reactor technology, based on BASF dual layer monolith catalyst, for miniaturizing the autothermal reforming of pyrolysis oil to syngas, the second and most critical of the three steps for thermochemically converting biomass waste to liquid transportation fuel. The technology was applied to aged as well as fresh samples of pyrolysis oil derived from five different biomass feedstocks, namely switch-grass, sawdust, hardwood/softwood, golden rod and maple. Optimization of process conditions in conjunction with innovative reactor system design enabled the minimization of carbon deposit and control of the H2/CO ratio of the product gas. A comprehensive techno-economic analysis of the integrated process using in part, experimental data from the project, indicates (1) net energy recovery of 49% accounting for all losses and external energy input, (2) weight of diesel oil produced as a percent of the biomass to be ~14%, and (3) for a demonstration size biomass to Fischer-Tropsch liquid plant of ~ 2000 daily barrels of diesel, the price of the diesel produced is ~$3.30 per gallon, ex. tax. However, the extension of catalyst life is critical to the realization of the projected economics. Catalyst deactivation was observed and the modes of deactivation, both reversible and irreversible were identified. An effective catalyst regeneration strategy was successfully demonstrated for reversible catalyst deactivation while a catalyst preservation strategy was proposed for preventing irreversible catalyst deactivation. Future work should therefore be focused on extending the catalyst life, and a successful demonstration of an extended (> 500 on-stream hours) catalyst life would affirm the commercial viability of the process.

  6. Renewable synthesis-gas-production. Do hydrocarbons in the reactant flow of the reverse water-gas shift reaction cause coke formation?

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, A.; Kern, C.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

    2013-11-01

    In a two-step synthetic fuel production process based on carbon dioxide and renewable hydrogen, the best possible selectivity towards liquid hydrocarbons (Hc) shall be implemented. The process consists of a combination of the Reverse Water-Gas Shift reaction and the Fischer-Tropsch synthesis. To achieve this goal, gaseous short-chained Hc from the FTS reactor are recycled in the RWGS unit. In this paper, challenges coming up with the implementation of a recycle loop are discussed. First of all, it has to be examined whether Hc are converted under conditions present in the RWGS reactor. The coking caused by the recycle of Hc is regarded, including thermal coking in the heating zone of the reactor and catalytic coking in the catalyst bed. Coking of course is unwanted, as it deactivates the catalyst. The scope of this work is to find out to which extent and under which conditions gaseous Hc can be recycled. Therefore, experiments were carried out in both, a quartz glass reactor using a commercial Ni-catalyst at ambient pressure and in a pressurized steel reactor (without catalyst) to examine coking during the thermal decomposition of Hc. The catalytic experiments at atmospheric pressure showed that a recycle of CH{sub 4} did not cause coking up to a ratio of CH{sub 4}/CO{sub 2} below one. For these conditions, long term stability was proved. The reaction rates of the CH{sub 4} conversion were below those of the RWGS reaction. However, replacing CH{sub 4} by C{sub 3}H{sub 8} leads to thermal and catalytic coking. Catalytic coking hits the maximum level at about 700 C and decreases for higher temperatures and, thus is not regarded as a problem for the RWGS reactor. In contrast to that, thermal coking raises with higher temperatures, but it can be supressed efficiently with additional injection of H{sub 2}O, which of course shifts the equilibrium towards the undesired reactant side. (orig.)

  7. Energy efficient methane tri-reforming for synthesis gas production over highly coke resistant nanocrystalline Ni–ZrO_2 catalyst

    International Nuclear Information System (INIS)

    Singha, Rajib Kumar; Shukla, Astha; Yadav, Aditya; Adak, Shubhadeep; Iqbal, Zafar; Siddiqui, Nazia; Bal, Rajaram

    2016-01-01

    Highlights: • Tri-reforming of methane is an energy efficient process to produce synthesis gas. • Nanocrystalline Ni–ZrO_2 catalyst is prepared for tri-reforming of methane. • Strong metal-support interaction is the driving force for high activity. • The process produces synthesis gas with H_2/CO ratio of around 2. • The produced synthesis gas can be used to synthesize methanol. - Abstract: We report the synthesis of nanocrystalline Ni–ZrO_2 catalyst for tri-reforming of methane (5CH_4 + O_2 + CO_2 + 2H_2O → 6CO + 12H_2) to produce synthesis gas with H_2/CO mole ratio ∼2. Nanocrystalline Ni–ZrO_2 catalyst of size between 10 and 40 nm was prepared by hydrothermal method using cetyltrimethylammonium bromide (CTAB) as a surfactant. The prepared catalysts were characterized by N_2-physisorption studies, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature programmed reduction (TPR), H_2-chemisorpton, thermo-gravimetric analysis (TGA), Inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS). The catalytic activity was monitored over temperature range between 500 and 800 °C. Different reaction parameters like temperature, Ni-loading, gas hourly space velocity (GHSV) and time on stream (TOS) were studied in detail. 4.8 wt% Ni loading for Ni–ZrO_2 catalyst was found to be the optimum Ni loading which showed the superior catalytic activity for methane tri-reforming. The catalyst was found to be stable for more than 100 h on time on stream with methane, carbon dioxide and steam conversion of ∼95% at 800 °C. The H_2/CO ratio was almost constant to 1.9 throughout the time on stream experiment. Highly dispersed nickel and the presence of strong metal support interaction were found to be the key factor for the superior activity of the catalyst. The effect of O_2 and H_2O concentration on reactant conversions and H_2/CO ratios were also

  8. Synthesis of Ce-doped SnO{sub 2} nanoparticles and their acetone gas sensing properties

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Xiaoxue, E-mail: lianxiaoxues@163.com; Li, Yan; Tong, Xiaoqiang; Zou, Yunling; Liu, Xiulin; An, Dongmin; Wang, Qiong

    2017-06-15

    Highlights: • The Ce-doped SnO{sub 2} nanoparticles were fabricated via a simple hydrothermal method. • Ce ions were successfully doped into the SnO{sub 2} lattice, and 5 wt% SnO{sub 2}:Ce had a higher specific surface area. • The Ce-doped SnO{sub 2} nanoparticles exhibited the highest response values and a well selectivity to acetone. - Abstract: Hydrothermal method was generally used to synthesis nanoparticles, which was used to fabricate pure and Ce-doped (3 wt%, 5 wt%, 7 wt%) SnO{sub 2} nanoparticles in this experiment. The as-prepared products were characterized by X-ray diffraction (XRD), energy dispersive spectrum (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET). The results clearly indicated that the nanoparticles were composed of SnO{sub 2} nanoparticles and Ce ions were successfully doped into the SnO{sub 2} lattice, and 5 wt% SnO{sub 2}:Ce has a higher specific surface area (173.53 m{sup 2}/g). Importantly, SnO{sub 2}:Ce sensor had obviously improved performance compared to pure SnO{sub 2} and exhibited the highest response values (50.5 for 50 ppm) and a well selectivity to acetone at 270 °C. It could detect acetone gas in a wide concentration range with very high response, good long-term stability and repeatability of response. The possible sensing mechanism was discussed in this paper.

  9. The Integration of a Structural Water Gas Shift Catalyst with a Vanadium Alloy Hydrogen Transport Device

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Thomas; Argyle, Morris; Popa, Tiberiu

    2009-06-30

    This project is in response to a requirement for a system that combines water gas shift technology with separation technology for coal derived synthesis gas. The justification of such a system would be improved efficiency for the overall hydrogen production. By removing hydrogen from the synthesis gas stream, the water gas shift equilibrium would force more carbon monoxide to carbon dioxide and maximize the total hydrogen produced. Additional benefit would derive from the reduction in capital cost of plant by the removal of one step in the process by integrating water gas shift with the membrane separation device. The answer turns out to be that the integration of hydrogen separation and water gas shift catalysis is possible and desirable. There are no significant roadblocks to that combination of technologies. The problem becomes one of design and selection of materials to optimize, or at least maximize performance of the two integrated steps. A goal of the project was to investigate the effects of alloying elements on the performance of vanadium membranes with respect to hydrogen flux and fabricability. Vanadium was chosen as a compromise between performance and cost. It is clear that the vanadium alloys for this application can be produced, but the approach is not simple and the results inconsistent. For any future contracts, large single batches of alloy would be obtained and rolled with larger facilities to produce the most consistent thin foils possible. Brazing was identified as a very likely choice for sealing the membranes to structural components. As alloying was beneficial to hydrogen transport, it became important to identify where those alloying elements might be detrimental to brazing. Cataloging positive and negative alloying effects was a significant portion of the initial project work on vanadium alloying. A water gas shift catalyst with ceramic like structural characteristics was the second large goal of the project. Alumina was added as a

  10. Synthesis gas generation by high pressure partial oxidation (HP POX {sup registered}); Synthesegaserzeugung durch Hochdruck-Partialoxidation (HP POX {sup registered})

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, B.; Seifert, P.; Zeissler, R. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Energieverfahrenstechnik und Chemieingenieurwesen; Walter, St. [Lurgi AG, Frankfurt/Main (Germany)

    2005-05-01

    The high pressure synthesis gas process HP POX (High Pressure Partial Oxidation) is a thermal conversion process, which converts e.g. natural gas or heavy residue oil with oxygen to fuel or synthesis gas. Innovative burner technologies allow autothermal catalytic or non-catalytic reforming of gaseous feedstock and gasification of liquid feed streams. Hydrogen and carbon monoxide rich synthesis gases with low methane content (particularly suitable as feed gas for methanol synthesis) can be generated. The technology represents a new generation of entrained flow gasification characterized by the new developed equipment and a design pressure of 100 bar. According to the feeds, the HP POX gasification process is the link between the downstream synthesis chemistry (use of gaseous and liquid feeds) and the power plant process (liquid or solid fuels as suspension or slurry). The HP POX development is carried out together with the Lurgi AG at the Institute for Energy Process Engineering and Chemical Engineering (IEC). The 5 MW HP POX test plant built in Freiberg by Lurgi is core of the joint research project, which is supported by the German Federal Ministry of Economics and Labour (BMWA), the Saxon Ministry of Science and the Fine Arts (SMWK), and the mg technologies ag (parent company of Lurgi). The conducted sets of experiments indicate that the unit can be operated in a safe, smooth and stable manner. During this periods of operation, which included nine test campaigns for autothermal reforming (ATR), the maximum pressure for ATR amounted to 70 bar which exceeds the current benchmark in industry for 30 bar. Main objective of R and D work is the development of modelling tools for extreme gasification conditions and different gasification principles of up to 100 bar. These tools are supposed to improve the understanding of the entire gasification process. Their development requires a systematic investigation of the reaction mechanisms and the interactions with the process

  11. The Effect of Process Parameters on the Synthesis of Ti and TiO2 Nanoparticles Producted by Electromagnetic Levitational Gas Condensation

    Directory of Open Access Journals (Sweden)

    Maryam Moazeni

    2012-10-01

    Full Text Available The nanoparticles of Ti and TiO2 have attracted extensive research interest because of their diverse applications in, for instance, catalysis, energy conversion, pigment and cosmetic manufacturing and biomedical engineering. Through this project, a one-step bulk synthesis method of electromagnetic levitational gas condensation (ELGC was utilized for the synthesis of monodispersed and crystalline Ti and TiO2 nanoparticles. Within the process, the Ti vapours ascending from the high temperature levitated droplet were condensed by an argon gas stream under atmospheric pressure. The TiO2 nanoparticles were produced by simultaneous injection of argon and oxygen into the reactor. The effects of flow rate of the condensing and oxidizing gases on the size and the size distribution of the nanoparticles were investigated. The particles were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD and image analysis. The process parameters for the synthesis of the crystalline Ti and TiO2 nanoparticles were determined.

  12. Hot coal gas desulfurization with manganese-based sorbents. Final report, September 1992--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hepworth, M.T.; Slimane, R.B.

    1994-11-01

    The focus of much current work being performed by the Morgantown Energy Technology Center (METC) of the Department of Energy on hot coal-derived fuel gas desulfurization is in the use of zinc-based sorbents. METC has shown interest in formulating and testing manganese-based pellets as alternative effective sulfur sorbents in the 700 to 1200{degree}C temperature range. To substantiate the potential superiority of Mn-based pellets, a systematic approach toward the evaluation of the desulfurizing power of single-metal sorbents is developed based on thermodynamic considerations. This novel procedure considered several metal-based sorbents and singled out manganese oxide as a prime candidate sorbent capable of being utilized under a wide temperature range, irrespective of the reducing power (determined by CO{sub 2}/CO ratio) of the fuel gas. Then, the thermodynamic feasibility of using Mn-based pellets for the removal of H{sub 2}S from hot-coal derived fuel gases, and the subsequent oxidative regeneration of loaded (sulfided) pellets was established. It was concluded that MnO is the stable form of manganese for virtually all commercially available coal-derived fuel gases. In addition, the objective of reducing the H{sub 2}S concentration below 150 ppMv to satisfy the integrated gasification combined cycle system requirement was shown to be thermodynamically feasible. A novel process is developed for the manufacture of Mn-based spherical pellets which have the desired physical and chemical characteristics required.

  13. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    International Nuclear Information System (INIS)

    Unknown

    2000-01-01

    The U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn(sub 2)TiO(sub 4) or ZnTiO(sub 3)), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO(sub 2)), is currently one of the leading sorbents. Overall chemical reactions with Zn(sub 2)TiO(sub 4) during the desulfurization (sulfidation)-regeneration cycle are shown. The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO(sub 2)

  14. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    International Nuclear Information System (INIS)

    Unknown

    1999-01-01

    The U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn(sub 2)TiO(sub 4) or ZnTiO(sub 3)), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO(sub 2)), is currently one of the leading sorbents. Overall chemical reactions with Zn(sub 2)TiO(sub 4) during the desulfurization (sulfidation)-regeneration cycle are shown. The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO(sub 2)

  15. Catalytic hydroprocessing of coal-derived gasification residues to fuel blending stocks: effect of reaction variables and catalyst on hydrodeoxygenation (HDO), hydrodenitrogenation (HDN), and hydrodesulfurization (HDS)

    Energy Technology Data Exchange (ETDEWEB)

    Dieter Leckel [Sasol Technology Research and Development, Sasolburg (South Africa). Fischer-Tropsch Refinery Catalysis

    2006-10-15

    Gas liquors, tar oils, and tar products resulting from the coal gasification of a high-temperature Fischer-Tropsch plant can be successfully refined to fuel blending components by the use of severe hydroprocessing conditions. High operating temperatures and pressures combined with low space velocities ensure the deep hydrogenation of refractory oxygen, sulfur, and nitrogen compounds. Hydrodeoxygenation, particularly the removal of phenolic components, hydrodesulfurization, and hydrodenitrogenation were obtained at greater than 99% levels using the NiMo and NiW on {gamma}-Al{sub 2}O{sub 3} catalysts. Maximum deoxygenation activity was achieved using the NiMo/{gamma}-Al{sub 2}O{sub 3} catalyst having a maximum pore size distribution in the range of 110-220{angstrom}. The NiMo/{gamma}-Al{sub 2}O{sub 3} catalyst, which also has a relatively high proportion of smaller pore sizes (35-60 {angstrom}), displays lower hydrogenation activity. 30 refs., 1 fig. 8 tabs.

  16. 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

  17. Facile synthesis of triazine-triphenylamine-based microporous covalent polymer adsorbent for flue gas CO2 capture

    KAUST Repository

    Das, Swapan Kumar; Wang, Xinbo; Lai, Zhiping

    2017-01-01

    The sustainable capture and sequestration of CO2 from flue gas emission is an important and unavoidable challenge to control greenhouse gas release and climate change. In this report, we describe a triazine-triphenylamine-based microporous covalent

  18. Preliminary Screening -- Technical and Economic Assessment of Synthesis Gas to Fuels and Chemicals with Emphasis on the Potential for Biomass-Derived Syngas

    Energy Technology Data Exchange (ETDEWEB)

    Spath, P. L.; Dayton, D. C.

    2003-12-01

    In principle, syngas (primarily consisting of CO and H2) can be produced from any hydrocarbon feedstock, including: natural gas, naphtha, residual oil, petroleum coke, coal, and biomass. The lowest cost routes for syngas production, however, are based on natural gas, the cheapest option being remote or stranded reserves. Economic considerations dictate that the current production of liquid fuels from syngas translates into the use of natural gas as the hydrocarbon source. Nevertheless, the syngas production operation in a gas-to-liquids plant amounts to greater than half of the capital cost of the plant. The choice of technology for syngas production also depends on the scale of the synthesis operation. Syngas production from solid fuels can require an even greater capital investment with the addition of feedstock handling and more complex syngas purification operations. The greatest impact on improving the economics of gas-to liquids plants is through (1) decreasing capital costs associated with syngas production and (2) improving the thermal efficiency with better heat integration and utilization. Improved thermal efficiency can be obtained by combining the gas-to-liquids plant with a power generation plant to take advantage of the availability of low-pressure steam. The extensive research and development efforts devoted to syngas conversion to fuels and chemicals are documented in a vast amount of literature that tracks the scientific and technological advancements in syngas chemistry. The purpose of this report is to review the many syngas to products processes and summarize the salient points regarding the technology status and description, chemistry, catalysts, reactors, gas cleanliness requirements, process and environmental performances, and economics. Table 1 lists the products examined in this study and gives some facts about the technology as well as advantages and disadvantages. Table 2 summarizes the catalysts, process conditions, conversions, and

  19. Synthesis and effect of physical aging on gas transport properties of a microporous polyimide derived from a novel spirobifluorene-based dianhydride

    KAUST Repository

    Ma, Xiaohua

    2015-02-17

    A novel generic method is reported for the synthesis of a spirobifluorene-based dianhydride (SBFDA). An intrinsically microporous polyimide was obtained by polycondensation reaction with 3,3′-dimethylnaphthidine (DMN). The corresponding polymer (SBFDA-DMN) exhibited good solubility, excellent thermal stability, as well as significant microporosity with high BET surface area of 686 m2/g. The O2 permeability of a methanol-treated and air-dried membrane was 1193 Barrer with a moderate O2/N2 selectivity of 3.2. The post-treatment history and aging conditions had great effects on the membrane performance. A significant drop in permeability coupled with an increase in selectivity was observed after long-term aging. After storage of 200 days, the gas separation properties of SBFDA-DMN were located slightly above the latest Robeson upper bounds for several gas pairs such as O2/N2 and H2/N2.

  20. Gas-phase acylation of aminopropyl-silica gel in the synthesis of some chemically bonded silica materials for analytical applications

    International Nuclear Information System (INIS)

    Basiuk, Vladimir; Khil'chevskaya, E.G.

    1991-01-01

    Gas-phase acylation of aminopropyl-silica gel with aliphatic dicarboxylic (succinic, adipic and sebacic) and 4-aminobenzoic acids is proposed as a rapid and efficient one-step method for the synthesis of carboxyalkyl- and 4-aminophenylamidopropyl-silica gels, usually used as zwitterion exchangers for liquid chromatography and matrices for multi-step syntheses of silica-bound aromatic azo reagents for the sorption and chromatographic separation of metal ions. Acylation degrees of 59-90% are achieved after 0.5 h. IR spectra of the acylation products and near-UV-visible spectra for bonded aromatic azo compounds, based on 4-aminobenzamidopropyl-silica gel, are presented. Some positive and negative aspects of the gas-phase acylation are discussed. (author). 34 refs.; 2 figs.; 2 tabs

  1. Synthesis and effect of physical aging on gas transport properties of a microporous polyimide derived from a novel spirobifluorene-based dianhydride

    KAUST Repository

    Ma, Xiaohua; Ghanem, Bader; Salinas, Octavio; Litwiller, Eric; Pinnau, Ingo

    2015-01-01

    A novel generic method is reported for the synthesis of a spirobifluorene-based dianhydride (SBFDA). An intrinsically microporous polyimide was obtained by polycondensation reaction with 3,3′-dimethylnaphthidine (DMN). The corresponding polymer (SBFDA-DMN) exhibited good solubility, excellent thermal stability, as well as significant microporosity with high BET surface area of 686 m2/g. The O2 permeability of a methanol-treated and air-dried membrane was 1193 Barrer with a moderate O2/N2 selectivity of 3.2. The post-treatment history and aging conditions had great effects on the membrane performance. A significant drop in permeability coupled with an increase in selectivity was observed after long-term aging. After storage of 200 days, the gas separation properties of SBFDA-DMN were located slightly above the latest Robeson upper bounds for several gas pairs such as O2/N2 and H2/N2.

  2. Synthesis of Hydrocarbons from H2-Deficient Syngas in Fischer-Tropsch Synthesis over Co-Based Catalyst Coupled with Fe-Based Catalyst as Water-Gas Shift Reaction

    Directory of Open Access Journals (Sweden)

    Ting Ma

    2015-01-01

    Full Text Available The effects of metal species in an Fe-based catalyst on structural properties were investigated through the synthesis of Fe-based catalysts containing various metal species such, as Mn, Zr, and Ce. The addition of the metal species to the Fe-based catalyst resulted in high dispersions of the Fe species and high surface areas due to the formation of mesoporous voids about 2–4 nm surrounded by the catalyst particles. The metal-added Fe-based catalysts were employed together with Co-loaded beta zeolite for the synthesis of hydrocarbons from syngas with a lower H2/CO ratio of 1 than the stoichiometric H2/CO ratio of 2 for the Fischer-Tropsch synthesis (FTS. Among the catalysts, the Mn-added Fe-based catalyst exhibited a high activity for the water-gas shift (WGS reaction with a comparative durability, leading to the enhancement of the CO hydrogenation in the FTS in comparison with Co-loaded beta zeolite alone. Furthermore, the loading of Pd on the Mn-added Fe-based catalyst enhanced the catalytic durability due to the hydrogenation of carbonaceous species by the hydrogen activated over Pd.

  3. Synthesis and characterization of tungsten carbide doped cobalt via gas-solid reaction in rotary bed reactor; Sintese e caracterizacao de carbeto de tungstenio dopado com cobalto via reacao gas-solido em reator de leito rotativo

    Energy Technology Data Exchange (ETDEWEB)

    Tertuliano, R.S.C.; Araujo, C.P.B. de; Frota, A.V.V.M.; Moriyama, A.L.L.; Souza, C.P. de, E-mail: ruasavio@hotmail.com [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Departamento de Engenharia Quimica

    2016-07-01

    The search for materials with high added value, high applicability and sustainability, motivates innovations in all areas of engineering. In this context, so-called doped carbides, ceramic and metal compounds are included. This work proposes the synthesis and characterization of tungsten carbide doped cobalt (WC-Co) through the gas-solid reaction in a rotating bed reactor. The production stages of the material are: precursor synthesis by wetting, drying at 80 deg C, characterization of the precursor by MEV, DRX and FRX, gas-solid reaction at 750 deg C in a reducing atmosphere of CH{sub 4} / H{sub 2} in a rotary reactor at 34 rpm and characterization of the reaction product by the techniques already mentioned. The results showed that tungsten carbide powders were produced with cobalt inserted into the structure, with high surface area, nanometric grains and with potential for applications in the areas of catalysis, reactors and fuel cells, showing the relevance of this type of research.

  4. Synthesis and Characterization of Pure and Al Modified BaSnO3 Thick Film Resistor and Studies of its Gas Sensing Performance

    Directory of Open Access Journals (Sweden)

    N. U. PATIL

    2013-02-01

    Full Text Available In this work we report the synthesis, microstructure, electric properties and sensing performance of BaSnO3 (BS powder, it was prepared by solid state mechano-chemical method. As prepared powder is calcinated at temperatures 1000 °C and 1200 °C and tested for crystallization. Thick films were prepared using simple yet effective screen-printing technology. Structural and electrical analyses were performed and the results have been correlated. The pure BS film shows good response (S=9.8 to NH3 at elevated temperature up to 500 °C along with response other gases with lower sensitivity such as CO2, CO, H2S for various gas concentrations, when the pure film is surface modified with Al2O3, film improves the selectivity and sensitivity. Maximum response (S=21.2 was found to H2S gas at temperature of 300 °C for gas concentration as low as up to 100 ppm. The characterization of the films was done by XRD, SEM and TGA. Crystallite size, surface area, electric properties and gas sensitivity of the films were measured and presented.

  5. Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup, and Oxygen Separation Equipment; Task 1: Cost Estimates of Small Modular Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nexant Inc.

    2006-05-01

    This deliverable is the Final Report for Task 1, Cost Estimates of Small Modular Systems, as part of NREL Award ACO-5-44027, ''Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup and Oxygen Separation Equipment''. Subtask 1.1 looked into processes and technologies that have been commercially built at both large and small scales, with three technologies, Fluidized Catalytic Cracking (FCC) of refinery gas oil, Steam Methane Reforming (SMR) of Natural Gas, and Natural Gas Liquids (NGL) Expanders, chosen for further investigation. These technologies were chosen due to their applicability relative to other technologies being considered by NREL for future commercial applications, such as indirect gasification and fluidized bed tar cracking. Research in this subject is driven by an interest in the impact that scaling has on the cost and major process unit designs for commercial technologies. Conclusions from the evaluations performed could be applied to other technologies being considered for modular or skid-mounted applications.

  6. {alpha}-Al{sub 2}O{sub 3} catalyst supports for synthesis gas production: influence of different alumina bonding agents on support and catalyst properties

    Energy Technology Data Exchange (ETDEWEB)

    Marturano, M. [Centro de Investigacion y Desarrollo en Procesos Cataliticos, La Plata (Argentina); Aglietti, E.F. [Centro de Tecnologia de Recursos Minerales y Ceramica (CETMIC), Gonnet (Argentina); Ferretti, O. [Centro de Investigacion y Desarrollo en Procesos Cataliticos, La Plata (Argentina)]|[Univ. Nacional de La Plata, Dept. de Ingenieria Quimica de la Facultad de Ingenieria, La Plata (Argentina)

    1997-02-01

    Aluminas are widely used as catalytic supports in chemical reactions. Reforming reactions to obtain synthesis gas requires good mechanical strength and low sintering behaviour. In this work, the influence of bentonite, aluminium phosphate and alumina gel as binder agents of a calcined {alpha}-Al{sub 2}O{sub 3} are analyzed with respect to support and catalytic properties. The {alpha}-Al{sub 2}O{sub 3} supports, calcined at 1300 C, are then impregnated with solutions of Ni and Al inorganic salts to obtain the catalysts and are finally tested in the reforming reaction of methane to synthesis gas at 500-900 C. Supports and catalysts are characterized by XRD, SEM, N{sub 2} adsorption, mechanical strength test and other techniques. Mechanical strength depends on the type and quantity of binder material used during support preparation. The influence of the support on the performance of the resulting catalyst is evidenced by means of catalytic tests. (orig.) 8 refs.

  7. Positions and synthesis of the seminar on the market of the natural gas; Planteamientos y sintesis del seminario sobre el mercado del gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez R, Raul

    1996-10-01

    In development of this event, the political, juridical, economic, environmental and social elements were analyzed that affect the formation of the national market, equally, the stimuli were discussed for the participation of the private sector, the decisive action promoter that has completed the state, to constitute enough reserves of natural gas, to build the infrastructure and to impel the formation of the market, as well as their perspectives and the possibilities to conform a culture of the use of the natural gas as product of the maturity of the market; the author also refers to the politicians of the national plan of development and the energy planning.

  8. Synthesis, characterization and gas sensing properties of undoped and Zn-doped γ-Fe2O3-based gas sensors

    International Nuclear Information System (INIS)

    Jing Zhihong

    2006-01-01

    In this study, undoped and Zn-doped γ-Fe 2 O 3 nanopowders have been prepared using Fe(NO 3 ) 3 .9H 2 O and Zn(NO 3 ) 2 .6H 2 O as starting materials and lauryl alcohol as anhydrous medium. Thermo-gravimetric analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD) and transmission electron micrograph (TEM) were employed to characterize the products. Sensitivity characteristics of the undoped and Zn-doped γ-Fe 2 O 3 semiconductor gas sensors have been investigated. The results show that both of the undoped and 15 mol% Zn-doped γ-Fe 2 O 3 -based gas sensors present good sensitivity and selectivity to acetone and ethanol in presence of CH 4 , H 2 and CO at the operating temperatures of 240 and 270 deg. C, respectively. After being doped with 15 mol% Zn addition, the γ-Fe 2 O 3 -based gas element displays higher sensitivity and selectivity as well as shorter response-recovery time compared with the undoped, suggesting that the promoting effect of ZnO is excellent. So, it seems that the γ-Fe 2 O 3 -based gas sensor doped with 15 mol% Zn is expected to be a promising sensor for detecting acetone and ethanol

  9. Synthesis and Characterization of a Novel Microporous Dihydroxyl-Functionalized Triptycene-Diamine-Based Polyimide for Natural Gas Membrane Separation

    KAUST Repository

    Alaslai, Nasser Y.; Ma, Xiaohua; Ghanem, Bader; Wang, Yingge; Alghunaimi, Fahd; Pinnau, Ingo

    2017-01-01

    plasticization resistance of 6FDA-DAT1-OH with impressive performance as potential membrane material for natural gas sweetening with a CO2 permeability of 50 Barrer and CO2 /CH4 selectivity of 40 at a typical natural gas well partial pressure of 10 atm.

  10. Methanol from coal without CO2 production via the modular high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Schleicher, R.W. Jr.; Engler, D.; Labar, M.P.

    1992-01-01

    Displacement options for petroleum fuels include natural gas (compressed or liquified), synthetic gasoline, biomass fuels, electric vehicles, hydrogen, and methanol. This paper reports that although no alternative meets all the desired characteristics of economics, environmental impact, supply logistics, and vehicle technology, methanol has often been cited as a good compromise and is perhaps the best coal derived fuel. The main criticism leveled at methanol is whether it can be produced economically in sufficient quantities to significantly displace petroleum-derived fuels. Although methanol can be manufactured from biomass, natural gas or coal feedstocks, only coal offers the potential for a substantial long term indigenous U.S. feedstock

  11. The combined use of micro-hydropyrolysis and compound-specific isotope analysis (CSIA) as a novel technique to identify coal-derived biodegraded PAH flux in the complex environment

    Energy Technology Data Exchange (ETDEWEB)

    Cheng-Gong Sun; Gbolagade Olalere; Wisdom Ivwurie; Mick Cooper; Colin Snape [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre

    2007-07-01

    A novel analytical methodology combining CSIA and micro-hydropyrolysis (CSIA/micro-HyPy) has been developed to aid unambiguous source apportionment of PAHs in the complex environment where PAH matrices have been heavily biodegraded and/or their isotopic signatures are overlapping for some sources. Asphaltenes retain useful information of biogeochemical significance, which can be accessed via hydropyrolysis. The PAHs released from hydropyrolysis of asphaltenes, the bound PAHs, from different primary sources (e.g. crude oils, low and high temperature coal tars) were characterized and compared to free aromatics in regard to their molecular and 13C-isotopic profiles. It was found that hydropyrolysis of asphaltenes can generate molecular and isotopic profiles highly representative of their primary sources. For both low and high temperature coal tar, the bound aromatics have broadly similar molecular distributions to their free aromatic counterparts and have {sup 13}C-isotopic values almost identical to those of UK bituminous coals(-23{per_thousand}), indicating that the asphaltenes are actually released as representative fragments of coal structures during carbonization. As expected, the bound aromatics are more 13C-enriched by 1-3 {per_thousand} (-21 to -23{per_thousand}) compared to free aromatics (-24 to -26{per_thousand}). No significant isotopic difference was observed between free and bound aromatics for a North Sea crude oil, all having similar {sup 13}C-isotopic values (-27.2-30.2 {per_thousand}) that are significantly lighter than those for coal-derived aromatics. Applications of this novel methodological CSIA/micro-HyPy technique to samples previously examined from an area around a former carbonization plant have been successfully demonstrated where unambiguous source apportionment could not be achieved previously for the PAHs due to likely environmental alternation. 3 refs., 2 figs., 2 tabs.

  12. Au@NiO core-shell nanoparticles as a p-type gas sensor: Novel synthesis, characterization, and their gas sensing properties with sensing mechanism

    KAUST Repository

    Majhi, Sanjit Manohar

    2018-04-25

    In this work, Au@NiO core-shell nanoparticles (C-S NPs) as a p-type gas sensing material was synthesized by a facile wet-chemical method, and evaluated their gas sensing properties as compared to the pristine NiO NPs gas sensors. Transmission electron microscope (TEM) results exhibited the well-dispersed formation of Au@NiO C-S NPs having the total size of 70–120 nm and NiO shells having 30–50 nm thickness. The C-S morphology as well as the overall particle sizes are unchanged even at 500 °C. The gas sensing result reveals that the response of Au@NiO C-S NPs gas sensor is higher than pristine NiO NPs gas sensor for 100 ppm of ethanol at 200 °C operating temperature. The baseline resistance in the air for Au@NiO C-S NPs sensor is lowered as compared to pristine NiO NPs, which is due to the increased number of holes as charge carriers in Au@NiO C-S NPs. The high response of Au@NiO core-shell NPs as compared to pristine NiO NPs is attributed to electronic and chemical sensitization effects of Au. In Au@NiO C-S structure, the contact between metal (Au) and semiconductor (NiO) formed a Schottky junction since Au metal acted as electron acceptor, a withdrawal of electrons from NiO by Au metal core leaved behind number of holes as charge carriers in Au@NiO C-S NPs. Therefore, the baseline resistance of Au@NiO C-S NPs greatly decreased than pristine NiO NPs, as a result the Au@NiO C-S NPs showed higher response. On the other hand, in chemical sensitization effect, Au NPs catalyzed to dissociate O2 molecules into ionic species. This work will give some clue to the researchers for the further development of p-type based C-S NPs sensors.

  13. β-Molybdenum nitride: synthesis mechanism and catalytic response in the gas phase hydrogenation of p-chloronitrobenzene

    NARCIS (Netherlands)

    Cárdenas-Lizana, F.; Gómez-Quero, S.; Perret, N.; Kiwi-Minsker, L.; Keane, M.A.

    2011-01-01

    A temperature programmed treatment of MoO3 in flowing N2 + H2 has been employed to prepare β-phase molybdenum nitride (β-Mo2N) which has been used to promote, for the first time, the catalytic hydrogenation of p-chloronitrobenzene. The reduction/nitridation synthesis steps have been monitored in

  14. Design and Synthesis of Polyimides Based on Carbocyclic Pseudo-Tröger’s Base-Derived Dianhydrides for Membrane Gas Separation Applications

    KAUST Repository

    Ma, Xiaohua

    2017-07-24

    Two novel carbocyclic pseudo-Tröger’s base-derived dianhydrides, 5,6,11,12-tetrahydro-5,11-methanodibenzo[a,e][8]annulene-2,3,8,9-tetracarboxylic anhydride (CTB1) and its dione-substituted analogue 6,12-dioxo-5,6,11,12-tetrahydro-5,11-methanodibenzo[a,e][8]annulene-2,3,8,9-tetracarboxylic dianhydride (CTB2), were made and used for the synthesis of soluble polyimides of intrinsic microporosity with 3,3′-dimethylnaphthidine (DMN). The polyimides CTB1-DMN and CTB2-DMN exhibited excellent thermal stability of ∼500 °C and high BET surface areas of 580 and 469 m2 g–1, respectively. A freshly made dione-substituted CTB2-DMN membrane demonstrated promising gas separation performance with O2 permeability of 206 barrer and O2/N2 selectivity of 5.2. A higher O2 permeability of 320 barrer and lower O2/N2 selectivity of 4.2 were observed for a fresh CTB1-DMN film due to its higher surface area and less tightly packed structure as indicated by weaker charge-transfer complex interactions. Physical aging over 60 days resulted in reduction in gas permeability and moderately enhanced selectivity. CTB2-DMN exhibited notable performance with gas permeation data located between the 2008 and 2015 permeability/selectivity upper bounds for O2/N2 and H2/CH4.

  15. Mathematical modeling of synthesis gas fueled electrochemistry and transport including H2/CO co-oxidation and surface diffusion in solid oxide fuel cell

    Science.gov (United States)

    Bao, Cheng; Jiang, Zeyi; Zhang, Xinxin

    2015-10-01

    Fuel flexibility is a significant advantage of solid oxide fuel cell (SOFC). A comprehensive macroscopic framework is proposed for synthesis gas (syngas) fueled electrochemistry and transport in SOFC anode with two main novelties, i.e. analytical H2/CO electrochemical co-oxidation, and correction of gas species concentration at triple phase boundary considering competitive absorption and surface diffusion. Staring from analytical approximation of the decoupled charge and mass transfer, we present analytical solutions of two defined variables, i.e. hydrogen current fraction and enhancement factor. Giving explicit answer (rather than case-by-case numerical calculation) on how many percent of the current output contributed by H2 or CO and on how great the water gas shift reaction plays role on, this approach establishes at the first time an adaptive superposition mechanism of H2-fuel and CO-fuel electrochemistry for syngas fuel. Based on the diffusion equivalent circuit model, assuming series-connected resistances of surface diffusion and bulk diffusion, the model predicts well at high fuel utilization by keeping fixed porosity/tortuosity ratio. The model has been validated by experimental polarization behaviors in a wide range of operation on a button cell for H2-H2O-CO-CO2-N2 fuel systems. The framework could be helpful to narrow the gap between macro-scale and meso-scale SOFC modeling.

  16. Prediction of thermodynamic properties of coal derivatives

    International Nuclear Information System (INIS)

    Donohue, M.D.

    1993-09-01

    We have developed new equations of state for pure-component chain molecules. The excellent performance of complicated theories, such as the Generalized Flory Dimer (GFD) theory can be mimicked by simpler equations, if assumptions for the shape parameters are made. We developed engineering correlations based on GFD theory, using local composition theory to take into account attractive forces. During this period, we compared methods for calculating repulsive and attractive contributions to equation of state against computer simulation data for hard and square-well chains, and against experimental data from the literature. We also have studied microstructure and local order in fluids that contain asymmetric molecules. We developed a thermodynamic model for polar compounds based on a site-site interaction approach. We have shown the equivalence of various classes of theories for hydrogen bonding, and used this equivalence to derive a multiple site model for water. In addition, simple cubic equations of state have been applied to calculate physical and chemical-reaction equilibria in nonideal systems. We measured infinite dilution activity coefficients using HPLC. We also measured high pressure vapor liquid equilibria of ternary and quaternary systems containing supercritical solvents. We used FT-IR spectroscopy to examine self-association of aliphatic alcohols due to hydrogen bonding, and to investigate the hydrogen bonding in polymer-solvent mixtures

  17. Hydrotreating of coal-derived liquids

    Energy Technology Data Exchange (ETDEWEB)

    Lott, S.E.; Stohl, F.V.; Diegert, K.V. [Sandia National Lab., Albuquerque, NM (United States)] [and others

    1995-12-31

    To develop a database relating hydrotreating parameters to feed and product quality by experimentally evaluating options for hydrotreating whole coal liquids, distillate cuts of coal liquids, petroleum, and blends of coal liquids with petroleum.

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

    OpenAIRE

    Blom, P.W.E.; Basson, G.W.

    2013-01-01

    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 ...

  19. Synthesis and morphology of iron-iron oxide core-shell nanoparticles produced by high pressure gas condensation

    NARCIS (Netherlands)

    Xing, Lijuan; ten Brink, Gert H.; Chen, Bin; Schmidt, Franz P.; Haberfehlner, Georg; Hofer, Ferdinand; Kooi, Bart J.; Palasantzas, Georgios

    2016-01-01

    Core-shell structured Fe nanoparticles (NPs) produced by high pressure magnetron sputtering gas condensation were studied using transmission electron microscopy (TEM) techniques, electron diffraction, electron energy-loss spectroscopy (EELS), tomographic reconstruction, and Wulff shape construction

  20. The synthesis of a new type adsorbent for the removal of toxic gas by radiation-induced graft polymerization

    International Nuclear Information System (INIS)

    Okamoto, Jiro; Sugo, Takanobu

    1990-01-01

    A new type of adsorbent containing sulfuric acid group for the removal of ammonia gas was synthesized by radiation-induced graft polymerization of styrene onto fibrous and nonwoven type polypropylene followed by sulufonation with chlorosulfonic acid. The rate of the adsorption of ammonia gas by H-type adsorbent is independent of the ion-exchange capacity. The amount of ammonia gas adsorbed by the chemical adsorption was dependent on the ion-exchange capacity of H-type fibrous adsorbent and was kept constant value in spite of the equilibrium pressure of ammonia gas. Cu(II)- and Ni(II)-types fibrous adsorbent were prepared by the ion exchange reaction of Na-type fibrous adsorbent with metal nitrate solutions. Although, the rate of adsorption of ammonia gas by metal-type fibrous adsorbent is lower than that of H-type adsorbent, the amount of ammonia gas adsorbed increases compared to H-type adsorbent with the same ion exchange capacity. It was related to the highest coordination number of metal ion. The ratio of the number of ammonia molecules adsorbed chemically and the number of metal ion adsorbed in fibrous adsorbent was 4 for Cu-type and 6 for Ni-type fibrous adsorbent, respectively. (author)

  1. Synthesis of Plate-Like Nanoalumina and Its Effect on Gas Permeability of Carbon Fiber Epoxy Composite

    Directory of Open Access Journals (Sweden)

    Ghadamali Karimi Khozani

    2017-03-01

    Full Text Available In recent years considerable efforts have been made to develop gas impermeable polymer systems. Compared with metal system counterparts they have advantages such as low density and production costs. The most important challenge in development of impermeable polymer systems is to reduce their gas permeability by proper selection of system composition and process conditions. In this work, nanoparticles were initially synthesized using Al (NO33•9H2O and sodium dodecyl sulfate as a structure-directing agent via hydrothermal method and a plate-like structure was characterized by FESEM and EDAX analyses. In the second step, epoxy/plate-like nanoalumina nanocomposites and epoxy-carbon fiber composites containing 1, 2.5, and 5 wt% nanoalumina were prepared. The effect of nanoparticle loading level on permeability of nitrogen, argon, and carbon dioxide in epoxy/plate-like nanoalumina nanocomposites was investigated. It was observed that the permeability of epoxy/plate-like nanoalumina nanocomposites toward nitrogen, argon, and carbon dioxide gases reduced 83%, 74%, and 50%, respectively. It was deduced that the permeability reduction was clearly associated with the diameter of gas molecules. Generally speaking, the results showed that the incorporation of plate-like nanoalumina particles significantly reduced the gas permeability. Also, carbon dioxide gas permeability of carbon fiber epoxy composites containing plate-like nanoalumina was investigated to show the effect of ingredients on the gas permeability of the system. The results indicated that carbon dioxide gas permeability of epoxy carbon fiber composite containing 5 wt% of plate-like nanoalumina was totally reduced 84%.

  2. Analysis of Mammalian Cell Proliferation and Macromolecule Synthesis Using Deuterated Water and Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Victoria C. Foletta

    2016-10-01

    Full Text Available Deuterated water (2H2O, a stable isotopic tracer, provides a convenient and reliable way to label multiple cellular biomass components (macromolecules, thus permitting the calculation of their synthesis rates. Here, we have combined 2H2O labelling, GC-MS analysis and a novel cell fractionation method to extract multiple biomass components (DNA, protein and lipids from the one biological sample, thus permitting the simultaneous measurement of DNA (cell proliferation, protein and lipid synthesis rates. We have used this approach to characterize the turnover rates and metabolism of a panel of mammalian cells in vitro (muscle C2C12 and colon cancer cell lines. Our data show that in actively-proliferating cells, biomass synthesis rates are strongly linked to the rate of cell division. Furthermore, in both proliferating and non-proliferating cells, it is the lipid pool that undergoes the most rapid turnover when compared to DNA and protein. Finally, our data in human colon cancer cell lines reveal a marked heterogeneity in the reliance on the de novo lipogenic pathway, with the cells being dependent on both ‘self-made’ and exogenously-derived fatty acid.

  3. Production of carbon nanotubes: Chemical vapor deposition synthesis from liquefied petroleum gas over Fe-Co-Mo tri-metallic catalyst supported on MgO

    Energy Technology Data Exchange (ETDEWEB)

    Setyopratomo, P., E-mail: puguh-sptm@yahoo.com; Wulan, Praswasti P. D. K., E-mail: wulanmakmur@gmail.com; Sudibandriyo, M., E-mail: msudib@che.ui.ac.id [Chemical Engineering Department, University of Indonesia, Depok Campus, Depok 16424 (Indonesia)

    2016-06-03

    Carbon nanotubes were produced by chemical vapor deposition method to meet the specifications for hydrogen storage. So far, the various catalyst had been studied outlining their activities, performances, and efficiencies. In this work, tri-metallic catalyst consist of Fe-Co-Mo supported on MgO was used. The catalyst was prepared by wet-impregnation method. Liquefied Petroleum Gas (LPG) was used as carbon source. The synthesis was conducted in atmospheric fixed bed reactor at reaction temperature range 750 – 850 °C for 30 minutes. The impregnation method applied in this study successfully deposed metal component on the MgO support surface. It found that the deposited metal components might partially replace Mg(OH){sub 2} or MgO molecules in their crystal lattice. Compare to the original MgO powder; it was significant increases in pore volume and surface area has occurred during catalyst preparation stages. The size of obtained carbon nanotubes is ranging from about 10.83 nm OD/4.09 nm ID up to 21.84 nm OD/6.51 nm ID, which means that multiwall carbon nanotubes were formed during the synthesis. Yield as much as 2.35 g.CNT/g.catalyst was obtained during 30 minutes synthesis and correspond to carbon nanotubes growth rate of 0.2 μm/min. The BET surface area of the obtained carbon nanotubes is 181.13 m{sup 2}/g and around 50 % of which is contributed by mesopores. Micropore with half pore width less than 1 nm contribute about 10% volume of total micro and mesopores volume of the carbon nanotubes. The existence of these micropores is very important to increase the hydrogen storage capacity of the carbon nanotubes.

  4. Ultrathin SnO2 nanorods: template- and surfactant-free solution phase synthesis, growth mechanism, optical, gas-sensing, and surface adsorption properties.

    Science.gov (United States)

    Xi, Guangcheng; Ye, Jinhua

    2010-03-01

    A novel template- and surfactant-free low temperature solution-phase method has been successfully developed for the controlled synthesis of ultrathin SnO(2) single-crystalline nanorods for the first time. The ultrathin SnO(2) single-crystalline nanorods are 2.0 +/- 0.5 nm in diameter, which is smaller than its exciton Bohr radius. The ultrathin SnO(2) nanorods show a high specific area (191.5 m(2) g(-1)). Such a thin SnO(2) single-crystalline nanorod is new in the family of SnO(2) nanostrucures and presents a strong quantum confinement effect. Its formation depends on the reaction temperature as well as on the concentration of the urea solution. A nonclassical crystallization process, Ostwald ripening process followed by an oriented attachment mechanism, is proposed based on the detailed observations from a time-dependent crystal evolution process. Importantly, such structured SnO(2) has shown a strong structure-induced enhancement of gas-sensing properties and has exhibited greatly enhanced gas-sensing property for the detection of ethanol than that of other structured SnO(2), such as the powders of nanobelts and microrods. Moreover, these ultrathin SnO(2) nanorods exhibit excellent ability to remove organic pollutant in wastewater by enormous surface adsorption. These properties are mainly attributed to its higher surface-to-volume ratio and ultrathin diameter. This work provides a novel low temperature, green, and inexpensive pathway to the synthesis of ultrathin nanorods, offering a new material form for sensors, solar cells, catalysts, water treatments, and other applications.

  5. Synthesis and Physical Properties of Nanocomposites (SnO2x(In2O31-x (x = 0 – 1 for Gas Sensors and Optoelectronics

    Directory of Open Access Journals (Sweden)

    Stanislav REMBEZA

    2010-11-01

    Full Text Available Experimental results on synthesis of thin film (< 1 μm nanocomposites (SnO2x(In2O31-x in the whole range of x = (0 – 1 mass. % are presented. Film nanocomposites were prepared by high-frequency magnetron sputtering of metal oxide targets in the controlled ambient Ar+O2. Films were deposited on the hot substrate (400 0C and investigated by X-ray phase analysis, atomic-force microscopy, optical and electrical methods. Influence of synthesis regimes and film composition on the grain size of crystals, the band-gap width, the transparency in the visible range of light, concentration and mobility of free charge carriers were determined. It was shown that films with composition (SnO2x(In2O31-x x = 0.9 are perspective for using as gas sensors, films of the same composition but with x = 0.1 can be applied as transparent current conducting electrodes for solar cells.

  6. Facile synthesis of triazine-triphenylamine-based microporous covalent polymer adsorbent for flue gas CO2 capture

    KAUST Repository

    Das, Swapan Kumar

    2017-07-17

    The sustainable capture and sequestration of CO2 from flue gas emission is an important and unavoidable challenge to control greenhouse gas release and climate change. In this report, we describe a triazine-triphenylamine-based microporous covalent organic polymer under mild synthetic conditions. 13C and 15N solid-state NMR and FTIR analyses confirm the linkage of the triazine and triphenylamine components in the porous polymer skeleton. The material is composed of spherical particles 1.0 to 2.0 μm in size and possesses a high surface area (1104 m2/g). The material exhibits superb chemical robustness under acidic and basic conditions and high thermal stability. Single-component gas adsorption exhibits an enhanced CO2 uptake of 3.12 mmol/g coupled with high sorption selectivity for CO2/N2 of 64 at 273 K and 1 bar, whereas the binary gas mixture breakthrough study using a model flue gas composition at 298 K shows a high CO2/N2 selectivity of 58. The enhanced performance is attributed to the high Lewis basicity of the framework, as it favors the interaction with CO2.

  7. Gas turbine topping combustor

    Science.gov (United States)

    Beer, J.; Dowdy, T.E.; Bachovchin, D.M.

    1997-06-10

    A combustor is described for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone. 14 figs.

  8. Rapid synthesis and characterization of hybrid ZnO@Au core–shell nanorods for high performance, low temperature NO{sub 2} gas sensor applications

    Energy Technology Data Exchange (ETDEWEB)

    Ponnuvelu, Dinesh Veeran [Nanosensor Laboratory, PSG Institute of Advanced Studies, Coimbatore 641 004 (India); Pullithadathil, Biji, E-mail: bijuja123@yahoo.co.in [Nanosensor Laboratory, PSG Institute of Advanced Studies, Coimbatore 641 004 (India); Prasad, Arun K.; Dhara, Sandip [Surface and Nanoscience Division, Indira Gandhi Center for Atomic Research, Kalpakkam (India); Ashok, Anuradha [Nanosensor Laboratory, PSG Institute of Advanced Studies, Coimbatore 641 004 (India); Mohamed, Kamruddin; Tyagi, Ashok Kumar [Surface and Nanoscience Division, Indira Gandhi Center for Atomic Research, Kalpakkam (India); Raj, Baldev [Nanosensor Laboratory, PSG Institute of Advanced Studies, Coimbatore 641 004 (India)

    2015-11-15

    Graphical abstract: - Highlights: • Hybrid ZnO@Au core–shell nanorods were developed using rapid chemical method that can be used as a high performance, low temperature NO{sub 2} gas sensor. • Surface defect analysis (PL and XPS) clearly illustrates the presence of surface oxygen species and Zn interstitials involved in charge transport properties in-turn affecting gas sensing properties. • Hybrid ZnO@Au core–shell nanorods establish enhanced gas sensing performance at 150 °C compared to ZnO (300 °C) with a lower detection limit of 500 ppb using conventional electrodes. • The enhanced performance of ZnO@Au core–shell nanorods based sensor was owing to the presence of Au nanoclusters on the surface of ZnO nanorods which is attributed to the formation of Schottky contacts at the interfaces leading to sensitization effects. • The hybrid material found to be selective toward NO{sub 2} gas and highly stable in nature. - Abstract: A rapid synthesis route for hybrid ZnO@Au core–shell nanorods has been realized for ultrasensitive, trace-level NO{sub 2} gas sensor applications. ZnO nanorods and hybrid ZnO@Au core–shell nanorods are structurally analyzed using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). Optical characterization using UV–visible (UV–vis), photoluminescence (PL) and Raman spectroscopies elucidate alteration in the percentage of defect and charge transport properties of ZnO@Au core–shell nanorods. The study reveals the accumulation of electrons at metal–semiconductor junctions leading to upward band bending for ZnO and thus favors direct electron transfer from ZnO to Au nanoclusters, which mitigates charge carrier recombination process. The operating temperature of ZnO@Au core–shell nanorods based sensor significantly decreased to 150 °C compared to alternate NO{sub 2} sensors (300 °C). Moreover, a linear sensor response in the range of 0.5–5

  9. The influence of seeding conditions and shielding gas atmosphere on the synthesis of silver nanowires through the polyol process

    Science.gov (United States)

    Chen, Chang; Wang, Li; Jiang, Guohua; Yang, Qiang; Wang, Jianjun; Yu, Haojie; Chen, Tao; Wang, Chiliang; Chen, Xu

    2006-01-01

    The polyol process including the introduction of preformed seeds and the inducement of poly(vinyl pyrrolidone) (PVP) has been developed as a powerful approach for synthesizing silver nanowires. Here, silver nanowires without other metal elements as impurities were synthesized through a silver seeding polyol process in a shielding gas atmosphere. It is demonstrated that the first seeding step is critical in obtaining silver nanowires as the principal product, and we also observe that the shielding gas atmosphere not only improves the repeatability of experiments but also affects the morphology of the final product. We obtained nanocubes with hydrogen gas shielding in a short reaction time; these would scarcely appear with argon or air shielding. Our work supplies new evidence to explain the actual growth mechanism of silver nanowires.

  10. Report on the service quality incentive regulations for gas network operators and ERDF. 2009-2010 Report Synthesis

    International Nuclear Information System (INIS)

    2010-11-01

    The latest natural gas transmission network tariffs, called 'ATRT4', and the tariffs for natural gas distribution network, 'ATRD3', as well as the 3. tariffs for using the public electricity networks, 'TURPE 3', constitute a regulatory framework offering incentives to gas transmission and distribution operators, as well as the electricity distributor ERDF, to control their costs and improve the quality of service provided for network users. For gas and electricity distribution system operators (DSO), the incentive-based regulation for quality of service implemented through the tariffs is complementary to the supervision powers of the licensing authorities. It operates by means of concession contracts which imply that the concessionaire has to deliver activity reports and that the licensing authorities have to publish monitoring reports of the concessionaire's activity. The licensing authorities act on the local level, whereas the incentive regulation is of national scope. The actions of the licensing authorities and of the Energy Regulatory Commission (CRE) contribute together to assess and enhance the quality of service of the DSO. As the service quality monitoring exercises are conducted successively, the analysis will become more refined as a greater data history is acquired. The quality of service from the gas network operators (GrDF, GRTgaz and TIGF) and the electricity distributor (ERDF) has been improving gradually over the period of the monitoring, or has stabilised at a satisfactory level for the areas that are most important for the correct functioning of the market. Some objectives set by the tariffs have been met or even exceeded, which earns financial bonuses for the operators in question. This second service quality monitoring report on the gas network operators and ERDF is going to be used by the CRE, in consultation with all the market players, to refine the incentive mechanisms already in place. Contents: 1

  11. Microwave-Assisted Synthesis of Graphene-SnO2 Nanocomposites and Their Applications in Gas Sensors.

    Science.gov (United States)

    Kim, Hyoun Woo; Na, Han Gil; Kwon, Yong Jung; Kang, Sung Yong; Choi, Myung Sik; Bang, Jae Hoon; Wu, Ping; Kim, Sang Sub

    2017-09-20

    We obtained extremely high and selective sensitivity to NO 2 gas by fabricating graphene-SnO 2 nanocomposites using a commercial microwave oven. Structural characterization revealed that the products corresponded to agglomerated structures of graphene and SnO 2 particles, with small secondary SnO x (x ≤ 2) nanoparticles deposited on the surfaces. The overall oxygen atomic ratio was decreased with the appearance of an SnO x (x graphene-SnO 2 nanocomposites, with the graphene promoting efficient transport of the microwave energy, evaporation and redeposition of SnO x nanoparticles were facilitated. The graphene-SnO 2 nanocomposites exhibited a high sensor response of 24.7 for 1 ppm of NO 2 gas, at an optimized temperature of 150 °C. The graphene-SnO 2 nanocomposites were selectively sensitive to NO 2 gas, in comparison with SO 2 , NH 3 , and ethanol gases. We suggest that the generation of SnO x nanoparticles and the SnO x phase in the matrix results in the formation of SnO 2 /SnO 2 homojunctions, SnO 2 /SnO x (x graphene heterojunctions, which are responsible for the excellent sensitivity of the graphene-SnO 2 nanocomposites to NO 2 gas. In addition, the generation of surface Sn interstitial defects is also partly responsible for the excellent NO 2 sensing performance observed in this study.

  12. Synthesis and Characterization of a Novel Microporous Dihydroxyl-Functionalized Triptycene-Diamine-Based Polyimide for Natural Gas Membrane Separation.

    Science.gov (United States)

    Alaslai, Nasser; Ma, Xiaohua; Ghanem, Bader; Wang, Yingge; Alghunaimi, Fahd; Pinnau, Ingo

    2017-09-01

    An intrinsically microporous polyimide is synthesized in m-cresol by a one-pot high-temperature condensation reaction of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and newly designed 2,6 (7)-dihydroxy-3,7(6)-diaminotriptycene (DAT1-OH). The 6FDA-DAT1-OH polyimide is thermally stable up to 440 °C, shows excellent solubility in polar solvents, and has moderately high Brunauer-Teller-Emmett (BET) surface area of 160 m 2 g -1 , as determined by nitrogen adsorption at -196 °C. Hydroxyl functionalization applied to the rigid 3D triptycene-based diamine building block results in a polyimide that exhibits moderate pure-gas CO 2 permeability of 70 Barrer combined with high CO 2 /CH 4 selectivity of 50. Mixed-gas permeation studies demonstrate excellent plasticization resistance of 6FDA-DAT1-OH with impressive performance as potential membrane material for natural gas sweetening with a CO 2 permeability of 50 Barrer and CO 2 /CH 4 selectivity of 40 at a typical natural gas well partial pressure of 10 atm. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Room temperature synthesis of free-standing HKUST-1 membranes from copper hydroxide nanostrands for gas separation.

    Science.gov (United States)

    Mao, Yiyin; shi, Li; Huang, Hubiao; Cao, Wei; Li, Junwei; Sun, Luwei; Jin, Xianda; Peng, Xinsheng

    2013-06-25

    Large scale, robust, well intergrown free-standing HKUST-1 membranes were converted from copper hydroxide nanostrand free-standing films in 1,3,5-benzenetricarboxylic acid water-ethanol solution at room temperature, and explored for gas separation. The truncated crystals are controllable and favorable for the dense intergrowth.

  14. Synthesis and Characterization of a Novel Microporous Dihydroxyl-Functionalized Triptycene-Diamine-Based Polyimide for Natural Gas Membrane Separation

    KAUST Repository

    Alaslai, Nasser Y.

    2017-07-10

    An intrinsically microporous polyimide is synthesized in m-cresol by a one-pot high-temperature condensation reaction of 4,4\\'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and newly designed 2,6 (7)-dihydroxy-3,7(6)-diaminotriptycene (DAT1-OH). The 6FDA-DAT1-OH polyimide is thermally stable up to 440 °C, shows excellent solubility in polar solvents, and has moderately high Brunauer-Teller-Emmett (BET) surface area of 160 m2 g-1 , as determined by nitrogen adsorption at -196 °C. Hydroxyl functionalization applied to the rigid 3D triptycene-based diamine building block results in a polyimide that exhibits moderate pure-gas CO2 permeability of 70 Barrer combined with high CO2 /CH4 selectivity of 50. Mixed-gas permeation studies demonstrate excellent plasticization resistance of 6FDA-DAT1-OH with impressive performance as potential membrane material for natural gas sweetening with a CO2 permeability of 50 Barrer and CO2 /CH4 selectivity of 40 at a typical natural gas well partial pressure of 10 atm.

  15. Synthesis and Characterization of Nano-Crystalline Cu and Pb0.5-Cu0.5- ferrites by Mechanochemical Method and Their Electrical and Gas Sensing Properties

    Directory of Open Access Journals (Sweden)

    V. B. GAIKWAD

    2011-11-01

    Full Text Available In the present communication, we have reported the synthesis of nanocrystalline ferrites of the type CuFe2O4 and Pb0.5Cu0.5Fe2O4 by mechanochemical alloying at 960 0C. The samples prepared were characterized by X-ray diffraction (XRD, VSM, FT-IR, UV-DRS, and SEM. The average particle size was determined by XRD pattern using Scherrer equation and it is 7.295 nm, 4.484 nm for CuFe2O4, and Pb0.5Cu0.5Fe2O4. The surface morphology of the samples is characterized by scanning electron microscopy (SEM. Magnetic studies were carried out using vibrating sample magnetometer (VSM and shows very high coercive field for the mixed ferrite. UV-DRS studies were performed to investigate the band gap of synthesized nanocrystalline material. Electrical properties show semiconducting nature of synthesized ferrites. The thick films of the material were prepared by screen printing method. The gas sensing properties were studied towards reducing gases like CO, NH3 and H2S and it was revealed that CuFe2O4 is the most sensitive and selective to H2S gas at relatively lower operating temperature 200 0C. Furthermore Pb0.5Cu0.5Fe2O4 also shows the response to H2S at operating temperature 300 0C.

  16. Bench-scale demonstration of biological production of ethanol from coal synthesis gas. Quarterly report, October 1, 1993--December 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    This project describes a new approach to coal liquefaction, the biological conversion of coal synthesis gas into a liquid fuel, ethanol. A new bacterium, Clostridium Ijungdahlii, strain PETC, has been discovered and developed for this conversion, which also produces acetate as a by-product. Based upon the results of an exhaustive literature search and experimental data collected in the ERI laboratories, secondary and/or branched alcohols have been selected for ethanol extraction from the fermentation broth. 2,6 Methyl 4-heptanol has a measured distribution coefficient of 0.44 and a separation factor of 47. Methods to improve the results from extraction by removing water prior to distillation are under consideration. Several runs were performed in the two-stage CSTR system with Clostridium Ijungdahlii, strain PETC, with and without cell recycle between stages. Reduced gas flow rate, trypticase limitation and ammonia limitation as methods of maximizing ethanol production were the focus of the studies. With ammonia limitation, the ethanol:acetate product ratio reached 4.0.

  17. Facile Synthesis of Polyaniline Nanotubes Using Self-Assembly Method Based on the Hydrogen Bonding: Mechanism and Application in Gas Sensing

    Directory of Open Access Journals (Sweden)

    Changqing Yin

    2017-10-01

    Full Text Available Based on hydrogen bonding, the highly uniform polyaniline (PANI nanotubes were synthesized by self-assembly method using citric acid (CA as the dopant and the structure-directing agent by optimizing the molar ratio of CA to aniline monomer (Ani. Synthesis conditions like reaction temperature and mechanical stirring were considered to explore the effects of hydrogen bonding on the morphologies. The effects of CA on the final morphology of the products were also investigated. The as-synthesized CA doped polyaniline (PANI nanomaterials were further deposited on the plate electrodes for the test of gas sensing performance to ammonia (NH3. The sensitivity to various concentrations of NH3, the repeatability, and the stability of the sensors were also tested and analyzed. As a result, it was found that the PANI nanomaterial synthesized at the CA/Ani molar ratio of 0.5 has highly uniform tubular morphology and shows the best sensing performance to NH3. It makes the PANI nanotubes a promising material for high performance gas sensing to NH3.

  18. A simple large-scale synthesis of mesoporous In{sub 2}O{sub 3} for gas sensing applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Su; Song, Peng, E-mail: mse_songp@ujn.edu.cn; Yan, Huihui; Yang, Zhongxi; Wang, Qi, E-mail: mse_wangq@ujn.edu.cn

    2016-08-15

    Graphical abstract: Large-scale mesoporous In{sub 2}O{sub 3} nanostructures for gas-sensing applications were successfully fabricated via a facile Lewis acid catalytic the furfural alcohol resin template route. - Highlights: • Mesoporous In{sub 2}O{sub 3} nanostructures with high-yield have been successfully fabricated via a facile strategy. • The microstructure and formation mechanism of mesoporous In{sub 2}O{sub 3} nanostructures were discussed based on the experimental results. • The as-prepared In{sub 2}O{sub 3} samples exhibited high response, short response-recovery times and good selectivity to ethanol gas. - Abstract: In this paper, large-scale mesoporous In{sub 2}O{sub 3} nanostructures were synthesized by a facile Lewis acid catalytic the furfural alcohol resin (FAR) template route for the high-yield. Their morphology and structure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal and thermogravimetry analysis (DSC-TG) and the Brunauer-Emmett-Teller (BET) approach. The as-obtained mesoporous In{sub 2}O{sub 3} nanostructures possess excellent mesoporous and network structure, which increases the contact area with the gases, it is conducive for adsorption-desorption of gas on the surface of In{sub 2}O{sub 3}. The In{sub 2}O{sub 3} particles and pores were both about 15 nm and very uniform. In gas-sensing measurements with target gases, the gas sensor based on mesoporous In{sub 2}O{sub 3} nanostructures showed a good response, short response-recovery time, good selectivity and stability to ethanol. These properties are due to the large specific surface area of mesoporous structure. This synthetic method could use as a new design concept for functional mesoporous nanomaterials and for mass production.

  19. A pair of polymorphous metal-organic frameworks based on an angular diisophthalate linker: synthesis, characterization and gas adsorption properties.

    Science.gov (United States)

    Chen, Fengli; Bai, Dongjie; Wang, Yao; He, Minghui; Gao, Xiaoxia; He, Yabing

    2018-01-15

    The combination of an angular diisophthalate ligand, 5,5'-(naphthyl-2,7-yl)diisophthalate (H 4 L), and copper ions under different solvothermal conditions afforded two polymorphous metal-organic frameworks (ZJNU-77 and ZJNU-78) with the same framework composition of [Cu 2 (L)(H 2 O) 2 ], providing a platform to investigate the relationship between MOF polymorphism and gas adsorption properties. As determined by single-crystal X-ray diffraction, ZJNU-77 and ZJNU-78 exhibited three-dimensional networks crystallizing in different space groups. Their structural differences were mainly manifested by the ligand's conformation, the level of framework interpenetration and the network's topology. Interestingly, gas adsorption studies showed that the two compounds after desolvation displayed comparable gas adsorption properties with respect to C 2 H 2 , CO 2 and CH 4 , despite their different surface areas and pore volumes. The C 2 H 2 , CO 2 , and CH 4 uptake capacities at 298 K and 1 atm are 120.2, 78.1, and 18.4 cm 3 (STP) g -1 for ZJNU-77, and 122.0, 82.0, and 18.9 cm 3 (STP) g -1 for ZJNU-78, respectively. The IAST adsorption selectivities for the equimolar C 2 H 2 /CH 4 and CO 2 /CH 4 mixtures are 28.6 and 5.7 for ZJNU-77, and 28.4 and 5.9 for ZJNU-78 at 298 K and 1 atm. These results indicate that besides the surface area, the pore size also plays a crucial role in gas adsorption. This work not only represents an intriguing example of MOF polymorphism achieved by controlling solvothermal conditions, but also provides an insight into the correlation between MOF polymorphism and gas adsorption properties.

  20. Amine-based post-combustion CO2 capture in air-blown IGCC systems with cold and hot gas clean-up

    International Nuclear Information System (INIS)

    Giuffrida, A.; Bonalumi, D.; Lozza, G.

    2013-01-01

    Highlights: • Hot fuel gas clean-up is a very favorable technology for IGCC concepts. • IGCC net efficiency reduces to 41.5% when realizing post-combustion CO 2 capture. • Complex IGCC layouts are necessary if exhaust gas recirculation is realized. • IGCC performance does not significantly vary with exhaust gas recirculation. - Abstract: This paper focuses on the thermodynamic performance of air-blown IGCC systems with post-combustion CO 2 capture by chemical absorption. Two IGCC technologies are investigated in order to evaluate two different strategies of coal-derived gas clean-up. After outlining the layouts of two power plants, the first with conventional cold gas clean-up and the second with hot gas clean-up, attention is paid to the CO 2 capture station and to issues related to exhaust gas recirculation in combined cycles. The results highlight that significant improvements in IGCC performance are possible if hot coal-derived gas clean-up is realized before the syngas fuels the combustion turbine, so the energy cost of CO 2 removal in an amine-based post-combustion mode is less strong. In particular, IGCC net efficiency as high as 41.5% is calculated, showing an interesting potential if compared to the one of IGCC systems with pre-combustion CO 2 capture. Thermodynamic effects of exhaust gas recirculation are investigated as well, even though IGCC performance does not significantly vary against a more complicated plant layout

  1. Combustion heating value gas in a gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Kelsall, G [CTDD, British Coal Corporation, Cheltenham (United Kingdom); Cannon, M [European Gas Turbines Ltd., Lincoln (United Kingdom)

    1997-12-31

    Advanced coal and/or biomass based power generation systems offer the potential for high efficiency electricity generation with minimum environmental impact. An important component for many of these advanced power generation cycles is the gas turbine, for which development of a combustion system to burn low calorific value coal derived fuel gas, at turbine inlet temperatures of typically 1 100 - 1 260 deg C and with minimum pollutant emissions, is a key issue. A phased combustor development programme is under-way burning low calorific value fuel gas (3.6 - 4.1 MJ/m{sup 3}) with low emissions, particularly NO{sub x} derived from fuel-bound nitrogen. The first and second phases of the combustor development programme have been completed. The first phase used a generic tubo-annular, prototype combustor based on conventional design principles. Combustor performance for this first prototype combustor was encouraging. The second phase assessed five design variants of the prototype combustor, each variant achieving a progressive improvement in combustor performance. The operating conditions for this assessment were selected to represent a particular medium sized industrial gas turbine operating as part of an Air Blown Gasification Cycle (ABGC). The test conditions assessed therefore included the capability to operate the combustor using natural gas as a supplementary fuel, to suit one possible start-up procedure for the cycle. The paper presents a brief overview of the ABGC development initiative and discusses the general requirements for a gas turbine operating within such a cycle. In addition, it presents full combustor performance results for the second phase of turbine combustor development and discusses the rationale for the progressive design modifications made within that programme. The strategy for the further development of the combustor to burn low calorific value fuel gas with very low conversion of fuel-bound nitrogen to NO{sub x} is presented. (orig.) 6 refs.

  2. Combustion heating value gas in a gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Kelsall, G. [CTDD, British Coal Corporation, Cheltenham (United Kingdom); Cannon, M. [European Gas Turbines Ltd., Lincoln (United Kingdom)

    1996-12-31

    Advanced coal and/or biomass based power generation systems offer the potential for high efficiency electricity generation with minimum environmental impact. An important component for many of these advanced power generation cycles is the gas turbine, for which development of a combustion system to burn low calorific value coal derived fuel gas, at turbine inlet temperatures of typically 1 100 - 1 260 deg C and with minimum pollutant emissions, is a key issue. A phased combustor development programme is under-way burning low calorific value fuel gas (3.6 - 4.1 MJ/m{sup 3}) with low emissions, particularly NO{sub x} derived from fuel-bound nitrogen. The first and second phases of the combustor development programme have been completed. The first phase used a generic tubo-annular, prototype combustor based on conventional design principles. Combustor performance for this first prototype combustor was encouraging. The second phase assessed five design variants of the prototype combustor, each variant achieving a progressive improvement in combustor performance. The operating conditions for this assessment were selected to represent a particular medium sized industrial gas turbine operating as part of an Air Blown Gasification Cycle (ABGC). The test conditions assessed therefore included the capability to operate the combustor using natural gas as a supplementary fuel, to suit one possible start-up procedure for the cycle. The paper presents a brief overview of the ABGC development initiative and discusses the general requirements for a gas turbine operating within such a cycle. In addition, it presents full combustor performance results for the second phase of turbine combustor development and discusses the rationale for the progressive design modifications made within that programme. The strategy for the further development of the combustor to burn low calorific value fuel gas with very low conversion of fuel-bound nitrogen to NO{sub x} is presented. (orig.) 6 refs.

  3. Synthesis of Aluminum-Aluminum Nitride Nanocomposites by a Gas-Liquid Reaction II. Microstructure and Mechanical Properties

    Science.gov (United States)

    Borgonovo, Cecilia; Makhlouf, Makhlouf M.

    2016-04-01

    In situ fabrication of the reinforcing particles in the metal matrix is an answer to many of the challenges encountered in manufacturing aluminum matrix nanocomposites. In this method, the nanoparticles are formed directly within the melt by means of a chemical reaction between a specially designed aluminum alloy and a gas. In this publication, we describe a process for synthesizing aluminum-aluminum nitride nanocomposites by reacting a nitrogen-containing gas with a molten aluminum-lithium alloy. We quantify the effect of the process parameters on the average particle size and particle distribution, as well as on the tendency of the particles to cluster in the alloy matrix, is quantified. Also in this publication, we present the measured room temperature and elevated temperature tensile properties of the nanocomposite material as well as its measured room temperature impact toughness.

  4. Synthesis of Nanocrystalline SnO2 Modified TiO2:a Material for Carbon Monoxide Gas Sensor

    Directory of Open Access Journals (Sweden)

    A. B. BODADE

    2008-11-01

    Full Text Available Nanocrystalline SnO2 doped TiO2 having average crystallite size of 45-50 nm were synthesized by the sol-gel method and studied for gas sensing behavior to reducing gases like CO, liquefied petroleum gas (LPG, NH3 and H2. The material characterization was done by using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR and scanning electron microscope (SEM. The sensitivity measurements were carried out as a function of different operating temperature in SnO2 doped TiO2. The 15 wt.% SnO2 doped TiO2 based CO sensor shows better sensitivity at an operating temperature 240°C Incorporation of 0.5 wt% Pd improved the sensitivity, selectivity, response time and reduced the operating temperature from 240°C to 200°C for CO sensor.

  5. Synthesis of Fe3O4 nanostructures by backward plume deposition and influence of ambient gas pressure on their morphology

    International Nuclear Information System (INIS)

    Lin, J J; Mahmood, S; Zhang, T; Hassan, S M; White, T; Ramanujan, R V; Lee, P; Rawat, R S

    2007-01-01

    Iron oxide nanostructures with significantly fewer droplets were successfully synthesized by pulsed laser deposition using a special target-substrate geometry, which is coined backward plume deposition. The morphology of deposited nanostructures for backward plume deposition is found to be strongly controlled by the ambient gas pressure and changes from a thin film to an assemble of nanoclusters to nanoclusters with loosely bound floccule-like network with the increase in ambient gas pressure. The post-annealing considerably changes the structural properties of deposited materials, which were determined to be magnetite FCC-Fe 3 O 4 . It also causes the relaxation of long range stress in the film and hence leads to an increase in the saturation magnetization. The coercivity is found to decrease upon annealing due to the growth of randomly oriented Fe 3 O 4 nanocrystallite as well as the relaxation of internal stress

  6. Synthesis of ZnO nanorods by spray pyrolysis for H{sub 2}S gas sensor

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, S.D.; Patil, G.E. [Materials Research Lab., K.T.H.M. College, Nashik 422 005 (India); Kajale, D.D. [Materials Research Lab., Arts, Commerce and Science College, Nandgaon 423 106 (India); Gaikwad, V.B. [Materials Research Lab., K.T.H.M. College, Nashik 422 005 (India); Jain, G.H., E-mail: gotanjain@rediffmail.com [Materials Research Lab., K.T.H.M. College, Nashik 422 005 (India)

    2012-07-05

    Highlights: Black-Right-Pointing-Pointer Hexagonal pillar shaped ZnO nanorods with different sizes have been successfully synthesized by spray pyrolysis technique. Black-Right-Pointing-Pointer ZnO nanorods thin films showed much better sensitivity and stability than the conventional materials to H{sub 2}S gas (100 ppm) at 50 Degree-Sign C. Black-Right-Pointing-Pointer This ZnO thin film has potential in application of room temperature H{sub 2}S gas sensing. - Abstract: Hexagonal pillar shaped ZnO nanorods with different sizes have been successfully synthesized by spray pyrolysis technique (SPT). The equal amount of methanol and water is used as a solvent to dissolve the AR grade Zinc acetate for precursor solution. This solution is sprayed on to the glass substrate heated at 350 Degree-Sign C. The films were characterized by ultra-violet spectroscopy (UV), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The deposition of thin films results in a layer comprising well-shaped hexagonal ZnO nanorods with diameter of 90-120 nm and length of up to 200 nm. The gas sensing properties of these films have been investigated for various interfering gases such as CO{sub 2}, CO, ethanol, NH{sub 3} and H{sub 2}S, etc. at operating temperature from 30 Degree-Sign (room temperature) to 450 Degree-Sign C. The results indicate that the ZnO nanorods thin films showed much better sensitivity and stability than the conventional materials to H{sub 2}S gas (100 ppm) at 50 Degree-Sign C. The hexagonal pillar shaped ZnO nanorods can improve the sensitivity and selectivity of the sensors.

  7. Synthesis of nickel-incorporated larch-based carbon membranes with controllable porous structure for gas separation

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xin; Li, Wei; Huang, Zhanhua; Liu, Shouxin, E-mail: chemist@126.com, E-mail: liushouxin@126.com [Northeast Forestry University, College of Material Science and Engineering (China)

    2015-11-15

    Ni-incorporated larch-based carbon membranes have been synthesized by introducing the Ni(NO{sub 3}){sub 2} into the liquefied larch using liquefied larch sawdust as precursors and F127 as the soft template. The porous structure can be tailored by the amount of Ni(NO{sub 3}){sub 2}, and the Ni and NiO nanoparticles with a size of 10 nm incorporated in the carbon frameworks. The increase in Ni(NO{sub 3}){sub 2} content can lead to the formation of disordered porous structure and shrinkage of carbon frameworks. The Ni-incorporated carbon membranes with largest pores possess highest gas permeation for N{sub 2}, CO{sub 2}, and O{sub 2} of 37.5, 19.8, and 55.5 m{sup 3} cm/m{sup 2} h kPa, which is larger than that of the pure carbon membranes, respectively. However, the poor ordered porous structure caused by adding large amount of Ni(NO{sub 3}){sub 2} can reduce the gas separation performance, which is attributed to the weaken of the molecular sieve function. The results indicate that the incorporation of few nanoparticles into larch-based carbon membranes can improve molecular sieve function.Graphical abstractNi-incorporated larch-based carbon membranes have been synthesized by introducing the Ni(NO{sub 3}){sub 2} into the liquefied larch. The porous structure can be tailored by the amount of Ni(NO{sub 3}){sub 2}, and the Ni and NiO nanoparticles incorporated in the carbon frameworks. The Ni-incorporated carbon membranes with largest pores possess highest gas permeation and gas permseparation.

  8. Synthesis of carbon nanotubes and iron oxide nanoparticles in MW plasma torch with Fe(CO)(5) in gas feed

    Czech Academy of Sciences Publication Activity Database

    Zajíčková, L.; Synek, P.; Jašek, O.; David, Bohumil; Buršík, Jiří; Pizúrová, Naděžda; Hanzlíková, Renáta; Lazar, L.; Eliáš, M.

    2009-01-01

    Roč. 255, č. 10 (2009), s. 5421-5424 ISSN 0169-4332 R&D Projects: GA ČR GA202/08/0178; GA AV ČR KAN311610701 Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z20650511 Keywords : carbon nanotubes * magnetite * hematite * iron pentacarbonyl Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.616, year: 2009

  9. Activation of methane by zinc: gas-phase synthesis, structure, and bonding of HZnCH3.

    Science.gov (United States)

    Flory, Michael A; Apponi, Aldo J; Zack, Lindsay N; Ziurys, Lucy M

    2010-12-08

    The methylzinc hydride molecule, HZnCH3, has been observed in the gas phase for the first time in the monomeric form using high-resolution spectroscopic techniques. The molecule was synthesized by two methods: the reaction of dimethylzinc with hydrogen gas and methane in an AC discharge and the reaction of zinc vapor produced in a Broida-type oven with methane in a DC discharge. HZnCH3 was identified on the basis of its pure rotational spectrum, which was recorded using millimeter/submillimeter direct-absorption and Fourier transform microwave techniques over the frequency ranges 332-516 GHz and 18-41 GHz, respectively. Multiple rotational transitions were measured for this molecule in seven isotopic variants. K-ladder structure was clearly present in all of the spectra, indicating a molecule with C3v symmetry and a (1)A1 ground electronic state. Extensive quadrupole hyperfine structure arising from the (67)Zn nucleus was observed for the H(67)ZnCH3 species, suggesting covalent bonding to the zinc atom. From the multiple isotopic substitutions, a precise structure for HZnCH3 has been determined. The influence of the axial hydrogen atom slightly distorts the methyl group but stabilizes the Zn-C bond. This study suggests that HZnCH3 can be formed through the oxidative addition of zinc to methane in the gas phase under certain conditions. HZnCH3 is the first metal-methane insertion complex to be structurally characterized.

  10. Facile Synthesis of a Pentiptycene-Based Highly Microporous Organic Polymer for Gas Storage and Water Treatment.

    Science.gov (United States)

    Luo, Shuangjiang; Zhang, Qinnan; Zhang, Yizhou; Weaver, Kevin P; Phillip, William A; Guo, Ruilan

    2018-05-02

    Rigid H-shaped pentiptycene units, with an intrinsic hierarchical structure, were employed to fabricate a highly microporous organic polymer sorbent via Friedel-Crafts reaction/polymerization. The obtained microporous polymer exhibits good thermal stability, a high Brunauer-Emmett-Teller surface area of 1604 m 2 g -1 , outstanding CO 2 , H 2 , and CH 4 storage capacities, as well as good adsorption selectivities for the separation of CO 2 /N 2 and CO 2 /CH 4 gas pairs. The CO 2 uptake values reached as high as 5.00 mmol g -1 (1.0 bar and 273 K), which, along with high adsorption selectivity values (e.g., 47.1 for CO 2 /N 2 ), make the pentiptycene-based microporous organic polymer (PMOP) a promising sorbent material for carbon capture from flue gas and natural gas purification. Moreover, the PMOP material displayed superior absorption capacities for organic solvents and dyes. For example, the maximum adsorption capacities for methylene blue and Congo red were 394 and 932 mg g -1 , respectively, promoting the potential of the PMOP as an excellent sorbent for environmental remediation and water treatment.

  11. Tuning Catalytic Performance through a Single or Sequential Post-Synthesis Reaction(s) in a Gas Phase

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Junjun [Department; Department; Zhang, Shiran [Department; Department; Choksi, Tej [Department; Nguyen, Luan [Department; Department; Bonifacio, Cecile S. [Department; Li, Yuanyuan [Department; Zhu, Wei [Department; Department; College; Tang, Yu [Department; Department; Zhang, Yawen [College; Yang, Judith C. [Department; Greeley, Jeffrey [Department; Frenkel, Anatoly I. [Department; Tao, Franklin [Department; Department

    2016-12-05

    Catalytic performance of a bimetallic catalyst is determined by geometric structure and electronic state of the surface or even the near-surface region of the catalyst. Here we report that single and sequential postsynthesis reactions of an as-synthesized bimetallic nanoparticle catalyst in one or more gas phases can tailor surface chemistry and structure of the catalyst in a gas phase, by which catalytic performance of this bimetallic catalyst can be tuned. Pt–Cu regular nanocube (Pt–Cu RNC) and concave nanocube (Pt–Cu CNC) are chosen as models of bimetallic catalysts. Surface chemistry and catalyst structure under different reaction conditions and during catalysis were explored in gas phase of one or two reactants with ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The newly formed surface structures of Pt–Cu RNC and Pt–Cu CNC catalysts strongly depend on the reactive gas(es) used in the postsynthesis reaction(s). A reaction of Pt–Cu RNC-as synthesized with H2 at 200 °C generates a near-surface alloy consisting of a Pt skin layer, a Cu-rich subsurface, and a Pt-rich deep layer. This near-surface alloy of Pt–Cu RNC-as synthesized-H2 exhibits a much higher catalytic activity in CO oxidation in terms of a low activation barrier of 39 ± 4 kJ/mol in contrast to 128 ± 7 kJ/mol of Pt–Cu RNC-as synthesized. Here the significant decrease of activation barrier demonstrates a method to tune catalytic performances of as-synthesized bimetallic catalysts. A further reaction of Pt–Cu RNC-as synthesized-H2 with CO forms a Pt–Cu alloy surface, which exhibits quite different catalytic performance in CO oxidation. It suggests the capability of generating a different surface by using another gas. The capability of tuning surface chemistry and structure of bimetallic catalysts was also demonstrated in restructuring of Pt–Cu CNC-as synthesized.

  12. Flash pyrolysis at high temperature of ligno-cellulosic biomass and its components - production of synthesis gas; Pyrolyse flash a haute temperature de la biomasse ligno-cellulosique et de ses composes - production de gaz de synthese

    Energy Technology Data Exchange (ETDEWEB)

    Couhert, C

    2007-11-15

    Pyrolysis is the first stage of any thermal treatment of biomass and governs the formation of synthesis gas for the production of electricity, hydrogen or liquid fuels. The objective of this work is to establish a link between the composition of a biomass and its pyrolysis gas. We study experimental flash pyrolysis and fix the conditions in which quantities of gas are maximal, while aiming at a regime without heat and mass transfer limitations (particles about 100 {mu}m): temperature of 950 C and residence time of about 2 s. Then we try to predict gas yields of any biomass according to its composition, applicable in this situation where thermodynamic equilibrium is not reached. We show that an additivity law does not allow correlating gas yields of a biomass with fractions of cellulose, hemi-cellulose and lignin contained in this biomass. Several explanations are suggested and examined: difference of pyrolytic behaviour of the same compound according to the biomass from which it is extracted, interactions between compounds and influence of mineral matter. With the aim of industrial application, we study pyrolysis of millimetric and centimetric size particles, and make a numerical simulation of the reactions of pyrolysis gases reforming. This simulation shows that the choice of biomass affects the quantities of synthesis gas obtained. (author)

  13. Synthesis of zeolite using as precursor reject of kaolin of the Amazon Region: application as an adsorbent in gas drying

    International Nuclear Information System (INIS)

    Morais, M.R.C.; Santana, D.L. de; Martelli, M.C.; Neves, R.F.

    2011-01-01

    Zeolites have large variety of technological applications, accounting for an increasing interest in various industries. In the State of Para, located three industries from kaolin for paper, where large amounts of waste are stored in ponds in becoming environmental problem. This work aims to develop a process for obtaining a zeolite P from the kaolin waste as the starting material. The synthesis was performed with kaolin waste from Capim River region, calcined at 700 ° C for 2 h, and reacted in the presence of aqueous NaOH and diatomite (silica source supplement), and the process hydrothermal temperature of 110 ° C for varied times. The characterization of the starting material and the synthesized materials was carried out using XRD and SEM. At the end of the experiment, the zeolite P synthesized was tested for moisture adsorption and was effective for this purpose. (author)

  14. A novel water perm-selective membrane dual-type reactor concept for Fischer-Tropsch synthesis of GTL (gas to liquid) technology

    International Nuclear Information System (INIS)

    Rahimpour, M.R.; Mirvakili, A.; Paymooni, K.

    2011-01-01

    The present study proposes a novel configuration of Fischer-Tropsch synthesis (FTS) reactors in which a fixed-bed water perm-selective membrane reactor is followed by a fluidized-bed hydrogen perm-selective membrane reactor. This novel concept which has been named fixed-bed membrane reactor followed by fluidized-bed membrane reactor (FMFMDR) produces gasoline from synthesis gas. The walls of the tubes of a fixed-bed reactor (water-cooled reactor) of FMFMDR configuration are coated by a high water perm-selective membrane layer. In this new configuration, two membrane reactors instead of one membrane reactor are developed for FTS reactions. In other words, two different membrane layers are used. In order to investigate the performance of FMFMDR, a one-dimensional heterogeneous model is taken into consideration. The simulation results of three schemes named fluidized-bed membrane dual-type reactor (FMDR), FMFMDR and conventional fixed-bed reactor (CR) are presented. They have been compared in terms of temperature, gasoline and CO 2 yields, H 2 and CO conversions and the water permeation rate through the membrane layer. Results show that the gasoline yield in FMFMDR is higher than the one in FMDR. The FMFMDR configuration not only decreases the undesired product such as CO 2 but also produces more gasoline. -- Research highlights: → The application of H-SOD membrane layer in FTS reactors. → Approximate 7.5% and 37% increase in the gasoline yield in terms of [g/g feed x 100] in comparison with FMDR and CR, respectively. → A remarkable decrease in CO 2 emission to the environment. → A good configuration mainly due to reduction in catalysts sintering as a result of in situ water removal.

  15. Synthesis of aluminum nitride films by plasma immersion ion implantation-deposition using hybrid gas-metal cathodic arc gun

    International Nuclear Information System (INIS)

    Shen Liru; Fu, Ricky K.Y.; Chu, Paul K.

    2004-01-01

    Aluminum nitride (AlN) is of interest in the industry because of its excellent electronic, optical, acoustic, thermal, and mechanical properties. In this work, aluminum nitride films are deposited on silicon wafers (100) by metal plasma immersion ion implantation and deposition (PIIID) using a modified hybrid gas-metal cathodic arc plasma source and with no intentional heating to the substrate. The mixed metal and gaseous plasma is generated by feeding the gas into the arc discharge region. The deposition rate is found to mainly depend on the Al ion flux from the cathodic arc source and is only slightly affected by the N 2 flow rate. The AlN films fabricated by this method exhibit a cubic crystalline microstructure with stable and low internal stress. The surface of the AlN films is quite smooth with the surface roughness on the order of 1/2 nm as determined by atomic force microscopy, homogeneous, and continuous, and the dense granular microstructures give rise to good adhesion with the substrate. The N to Al ratio increases with the bias voltage applied to the substrates. A fairly large amount of O originating from the residual vacuum is found in the samples with low N:Al ratios, but a high bias reduces the oxygen concentration. The compositions, microstructures and crystal states of the deposited films are quite stable and remain unchanged after annealing at 800 deg. C for 1 h. Our hybrid gas-metal source cathodic arc source delivers better AlN thin films than conventional PIIID employing dual plasmas

  16. Direct synthesis of Pt-free catalyst on gas diffusion layer of fuel cell and usage of high boiling point fuels for efficient utilization of waste heat

    International Nuclear Information System (INIS)

    Nandan, Ravi; Goswami, Gopal Krishna; Nanda, Karuna Kar

    2017-01-01

    Graphical abstract: Direct-grown boron-doped carbon nanotubes on gas-diffusion layer as efficient Pt-free cathode catalyst for alcohol fuel cells, high boiling point fuels used to obtain hot fuels for the enhancement of cell performance that paves the way for the utilization of waste heat. Display Omitted -- Highlights: •One-step direct synthesis of boron-doped carbon nanotubes (BCNTs) on gas diffusion layer (GDL). •Home built fuel-cell testing using BCNTs on GDL as Pt-free cathode catalyst. •BCNTs exhibit concentration dependent oxygen reduction reaction and the cell performance. •Effective utilization of waste heat to raise the fuel temperature. •Fuel selectivity to raise the fuel temperature and the overall performance of the fuel cells. -- Abstract: Gas diffusion layers (GDL) and electrocatalysts are integral parts of fuel cells. It is, however, a challenging task to grow Pt-free robust electrocatalyst directly on GDL for oxygen reduction reaction (ORR) – a key reaction in fuel cells. Here, we demonstrate that boron-doped carbon nanotubes (BCNTs) grown directly on gas-diffusion layer (which avoid the need of ionomer solution used for catalyst loading) can be used as efficient Pt-free catalyst in alcohol fuel cells. Increase in boron concentration improves the electrochemical ORR activity in terms of onset and ORR peak positions, half-wave potentials and diffusion-limited current density that ensure the optimization of the device performance. The preferential 4e − pathway, excellent cell performance, superior tolerance to fuel crossover and long-term stability makes directly grown BCNTs as an efficient Pt-free cathode catalyst for cost-effective fuel cells. The maximum power density of the fuel cell is found to increase monotonically with boron concentration. In addition to the application of BCNTs in fuel cell, we have introduced the concept of hot fuels so that waste heat can effectively be used and external power sources can be avoided. The fuel

  17. Synthesis of nano-bio conjugates for drug delivery systems using gas-liquid interfacial discharge plasmas

    International Nuclear Information System (INIS)

    Kaneko, Toshiro; Chen, Qiang; Hatakeyama, Rikizo

    2012-01-01

    Size-controlled gold nanoparticles (AuNPs) covered with DNA are synthesized by using a pulse driven gas-liquid interfacial discharge plasma (GLIDP) to reduce an aqueous solution of chloroauric acid trihydrate with DNA. The size and the assembly of the AuNPs are found to be easily controlled by changing the DNA concentration in the aqueous solution. The synthesized AuNP-DNA conjugates are forced to be encapsulated into double-walled carbon nanotubes (DWNTs) by superimposing a positive DC voltage on the pulse voltage. The AuNP-DNA-conjugate encapsulated DWNTs can be utilized in drug delivery systems when DNA is used as a drug molecule.

  18. Combined plasma gas-phase synthesis and colloidal processing of InP/ZnS core/shell nanocrystals

    OpenAIRE

    Hue Ryan; Gladfelter Wayne; Gresback Ryan; Kortshagen Uwe

    2011-01-01

    Abstract Indium phosphide nanocrystals (InP NCs) with diameters ranging from 2 to 5 nm were synthesized with a scalable, flow-through, nonthermal plasma process at a rate ranging from 10 to 40 mg/h. The NC size is controlled through the plasma operating parameters, with the residence time of the gas in the plasma region strongly influencing the NC size. The NC size distribution is narrow with the standard deviation being less than 20% of the mean NC size. Zinc sulfide (ZnS) shells were grown ...

  19. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    International Nuclear Information System (INIS)

    Unknown

    1999-01-01

    The U.S. Department of Energy (DOE), Federal Energy Technology Center (FETC), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn(sub 2) TiO(sub 4) or ZnTiO(sub 3)), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO(sub 2)), is currently one of the leading sorbents. Overall chemical reactions with Zn(sub 2) TiO(sub 4) during the desulfurization (sulfidation)-regeneration cycle are shown below: Sulfidation: Zn(sub 2) TiO(sub 4)+ 2H(sub 2)S(yields) 2ZnS+ TiO(sub 2)+ 2H(sub 2)O; Regeneration: 2ZnS+ TiO(sub 2)+ 3O(sub 2)(yields) Zn(sub 2) TiO(sub 4)+ 2SO(sub 2) The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO(sub 2)

  20. Terms of transactions monitoring on the French wholesale electricity and gas markets. Public consultation. Synthesis of contributions

    International Nuclear Information System (INIS)

    2008-01-01

    In its communication dated 16 April 2008, CRE published its practical methods used to monitor transactions concluded on the French electricity and gas markets. CRE invited any companies to comment on the practical arrangements of such monitoring activities. The monitoring system described by CRE is divided into two steps. In the first step, CRE wants to be able to request any information concerning transactions for physical delivery concluded after 1 January 2007. CRE will make an initial request that will focus on: - for electricity: transactions concluded in 2007 on yearly products for delivery in 2008 and 2009, base-load and peak-load; - for gas: transactions concluded in 2007 on seasonal and yearly products for delivery in 2008 and 2009, base-load and peak-load. The second step, based on feedback received, will see CRE liaise with market players and consider the possibility of setting up systematic procedures to gather transactions data. A final decision will be made by the end of 2008. 17 contributors responded to the public consultation. The remarks made on the practical methods used to gather data can be summarized along the following themes: Preamble: the monitoring principle; Theme 1: scope of transactions monitoring; Theme 2: content and format of requested data; Theme 3: procedures, transmission deadlines and confidentiality issues; Theme 4: stage II of systematic data gathering

  1. Synthesis, characterization and gas separation properties of novel polyimides containing cardo and tert-butyl-m-terphenyl moieties

    Directory of Open Access Journals (Sweden)

    L. A. Bermejo

    2018-05-01

    Full Text Available A series of aromatic polyimides has been obtained by the reaction of two dianhydrides, the commercial 2,2′-bis(3,4-dicarboxyphenylhexafluoropropane dianhydride (6FDA and another having a 5′-tert-butyl-m-terphenyl moiety (BTPDA, with several diamines, including two that have a cardo structure (derived from 9H-fluorene, one of them bearing methyl groups ortho to the amino functionalities (TMeCardo. The solubility, and also the thermal, mechanical, and gas separation properties of the corresponding polyimide membranes were evaluated and compared in order to explore the effect of the different groups in the polyimide backbone. The novel polyimides, which were derived from BTPDA and the cardo diamines, showed high thermal stability, excellent solubility in organic solvents and good gas separation properties, especially the polyimide that bore the ortho methyl substituents. The behavior was especially good for the pair O2/N2, where the TMeCardo polymer overpassed the Robeson upper bound.

  2. Synthesis of nickel-incorporated larch-based carbon membranes with controllable porous structure for gas separation

    Science.gov (United States)

    Zhao, Xin; Li, Wei; Huang, Zhanhua; Liu, Shouxin

    2015-11-01

    Ni-incorporated larch-based carbon membranes have been synthesized by introducing the Ni(NO3)2 into the liquefied larch using liquefied larch sawdust as precursors and F127 as the soft template. The porous structure can be tailored by the amount of Ni(NO3)2, and the Ni and NiO nanoparticles with a size of 10 nm incorporated in the carbon frameworks. The increase in Ni(NO3)2 content can lead to the formation of disordered porous structure and shrinkage of carbon frameworks. The Ni-incorporated carbon membranes with largest pores possess highest gas permeation for N2, CO2, and O2 of 37.5, 19.8, and 55.5 m3 cm/m2 h kPa, which is larger than that of the pure carbon membranes, respectively. However, the poor ordered porous structure caused by adding large amount of Ni(NO3)2 can reduce the gas separation performance, which is attributed to the weaken of the molecular sieve function. The results indicate that the incorporation of few nanoparticles into larch-based carbon membranes can improve molecular sieve function.

  3. Size-controlled synthesis of SnO2 quantum dots and their gas-sensing performance

    Science.gov (United States)

    Du, Jianping; Zhao, Ruihua; Xie, Yajuan; Li, Jinping

    2015-08-01

    Tin dioxide quantum dots (TQDs) with controllable size were synthesized by changing the amount of alkaline reagent in the hydrothermal process. The gas-sensing properties were investigated by operating chemoresistor type sensor. The morphology and structure were characterized by X-ray diffraction, scanning/transmission electron microscopy, UV-vis and Raman spectrometry. The as-synthesized SnO2 shows the characteristics of quantum dots and the narrowest size distribution is about 2-3 nm. The gas-sensing results indicate that the responses are strongly dependent on the size of quantum dots. TQDs with different sizes exhibit different sensitivities and selectivities to volatile toxic chemicals such as aldehyde, acetone, methanol, ethanol and amine. Especially, when the sensors are exposed to 100 ppm triethylamine (TEA), the sensing response value of TQDs with small size is two times higher than that of the large-size TQDs. The maximum response values of TQDs to 1 ppm and 100 ppm TEA are 15 and 153, respectively. The response time is 1 s and the recovery time is 47 s upon exposure to 1 ppm TEA. The results suggest that it is an effective method by regulating the size of SnO2 quantum dots to detect low-concentration hazardous volatile compounds.

  4. Sulfur Nanoparticles Synthesis and Characterization from H2S Gas, Using Novel Biodegradable Iron Chelates in W/O Microemulsion

    Directory of Open Access Journals (Sweden)

    Harle Arti

    2008-01-01

    Full Text Available AbstractSulfur nanoparticles were synthesized from hazardous H2S gas using novel biodegradable iron chelates in w/o microemulsion system. Fe3+–malic acid chelate (0.05 M aqueous solution was studied in w/o microemulsion containing cyclohexane, Triton X-100 andn-hexanol as oil phase, surfactant, co-surfactant, respectively, for catalytic oxidation of H2S gas at ambient conditions of temperature, pressure, and neutral pH. The structural features of sulfur nanoparticles have been characterized by X-ray diffraction (XRD, transmission electron microscope (TEM, energy dispersive spectroscopy (EDS, diffused reflectance infra-red Fourier transform technique, and BET surface area measurements. XRD analysis indicates the presence of α-sulfur. TEM analysis shows that the morphology of sulfur nanoparticles synthesized in w/o microemulsion system is nearly uniform in size (average particle size 10 nm and narrow particle size distribution (in range of 5–15 nm as compared to that in aqueous surfactant systems. The EDS analysis indicated high purity of sulfur (>99%. Moreover, sulfur nanoparticles synthesized in w/o microemulsion system exhibit higher antimicrobial activity (against bacteria, yeast, and fungi than that of colloidal sulfur.

  5. Facile synthesis of α-Fe{sub 2}O{sub 3} nanoparticles for high-performance CO gas sensor

    Energy Technology Data Exchange (ETDEWEB)

    Cuong, Nguyen Duc, E-mail: nguyenduccuong@hueuni.edu.vn [College of Sciences, Hue University, 77 Nguyen Hue, Phu Nhuan Ward, Hue City (Viet Nam); Faculty of Hospitality and Tourism, Hue University, 22 Lam Hoang, Vy Da Ward, Hue City (Viet Nam); Khieu, Dinh Quang; Hoa, Tran Thai [College of Sciences, Hue University, 77 Nguyen Hue, Phu Nhuan Ward, Hue City (Viet Nam); Quang, Duong Tuan [College of Education, Hue University, 34 Le Loi, Hue City (Viet Nam); Viet, Pham Hung [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, 334 Nguyen Trai, Hanoi (Viet Nam); Lam, Tran Dai [Graduate University of Science and Technology, Vietnamese Academy of Science and Technology, Hanoi (Viet Nam); Hoa, Nguyen Duc [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No. 1, Dai Co Viet, Hanoi (Viet Nam); Hieu, Nguyen Van, E-mail: hieu@itims.edu.vn [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No. 1, Dai Co Viet, Hanoi (Viet Nam)

    2015-08-15

    Highlights: • We have demonstrated a facile method to prepare Fe{sub 2}O{sub 3} nanoparticles. • The gas sensing properties of α-Fe{sub 2}O{sub 3} have been invested. • The results show potential application of α-Fe{sub 2}O{sub 3} NPs for CO sensors in environmental monitoring. - Abstract: Iron oxide nanoparticles (NPs) were prepared via a simple hydrothermal method for high performance CO gas sensor. The synthesized α-Fe{sub 2}O{sub 3} NPs were characterized by X-ray diffraction, nitrogen adsorption/desorption isotherm, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). The SEM, TEM results revealed that obtained α-Fe{sub 2}O{sub 3} particles had a peanut-like geometry with hemispherical ends. The response of the α-Fe{sub 2}O{sub 3} NPs based sensor to carbon monoxide (CO) and various concentrations of other gases were measured at different temperatures. It found that the sensor based on the peanut-like α-Fe{sub 2}O{sub 3} NPs exhibited high response, fast response–recovery, and good selectivity to CO at 300 °C. The experimental results clearly demonstrated the potential application of α-Fe{sub 2}O{sub 3} NPs as a good sensing material in the fabrication of CO sensor.

  6. Low-Temperature Synthesis and Gas Sensitivity of Perovskite-Type LaCoO3 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Lorenzo Gildo Ortiz

    2014-01-01

    Full Text Available LaCoO3 nanoparticles with perovskite-type structure were prepared by a microwave-assisted colloidal method. Lanthanum nitrate, cobalt nitrate, and ethylenediamine were used as precursors and ethyl alcohol as solvent. The thermal decomposition of the precursors leads to the formation of LaCoO3 from a temperature of 500°C. The structural, morphological, and compositional properties of LaCoO3 nanoparticles were studied in this work by X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, and atomic force microscopy (AFM. Pellets were manufactured in order to test the gas sensing properties of LaCoO3 powders in carbon monoxide (CO and propane (C3H8 atmospheres. Agglomerates of nanoparticles with high connectivity, forming a porous structure, were observed from SEM and TEM analysis. LaCoO3 pellets presented a high sensitivity in both CO and C3H8 at different concentrations and operating temperatures. As was expected, sensitivity increased with the gas concentration and operation temperature increase.

  7. Biomolecule-assisted synthesis and gas-sensing properties of porous nanosheet-based corundum In2O3 microflowers

    International Nuclear Information System (INIS)

    Zhang Wenhui; Zhang Weide

    2012-01-01

    Porous nanosheet-based corundum In 2 O 3 microflowers were fabricated by one-pot hydrothermal treatment of D-fructose and In(NO 3 ) 3 mixture using urea as a precipitating agent followed by calcination. The products were characterized by X-ray diffraction, scanning and transmission electron microscopy. The effects of D-fructose and urea on the fabrication of nanosheet-based corundum In 2 O 3 microflowers were investigated and a possible mechanism is proposed to explain the formation of the hierarchical nanostructures. The gas sensor based on the In 2 O 3 microflowers exhibits excellent sensing properties for the detection of formaldehyde. - Graphical abstract: Nanosheets-based corundum In 2 O 3 microflowers were fabricated by one-pot hydrothermal treatment of D-fructose/In(NO 3 ) 3 mixture followed by calcination, which show high performance for formaldehyde sensing. Highlights: ► Preparation of porous nanosheet-based corundum In 2 O 3 microflowers. ► Morphology and phase control of In 2 O 3 . ► Gas sensor based on the In 2 O 3 microflowers exhibits excellent sensing properties for the detection of formaldehyde.

  8. Synthesis, Characterization, and Gas-Sensing Properties of Mesoporous Nanocrystalline Sn(x)Ti(1-x)O2.

    Science.gov (United States)

    Zhong, Cheng; Lin, Zhidong; Guo, Fei; Wang, Xuehua

    2015-06-01

    A nanocomposite mesoporous material composed by SnO2 and TiO2 with the size of -5-9 nm were prepared via a facile wet-chemical approach combining with an annealing process. The microstructure of obtained Sn(x)Ti(1-x)O2 powders were characterized by X-ray diffraction, X-ray Photo-electronic Spectroscopy, scanning electron microscope, transmission electron microscope and nitrogen adsorption-desorption experiment. The gas sensing performances to several gases of the mesoporous material were studied. The sensors of Sn(x)Ti(1-x)O2 (ST10, with 9.1% Ti) exhibited very high responses to volatile organic compounds at 160 degrees C. The order of the responses to volatile gases based on ST10 was ethanol > formaldehyde > acetone > toluene > benzene > methane. Sensor based on ST10 displays a highest sensitivity to hydrogen at 200 degrees C. Sensor responses to H2 at 200 degrees C have been measured and analyzed in a wide concentration range from 5 to 2000 ppm. The solid solution Sn(x)Ti(1-x)O2 can be served as a potential gas-sensing material for a broad range of future sensor applications.

  9. 2,3-Butanediol Production by Acetogenic Bacteria, an Alternative Route to Chemical Synthesis, Using Industrial Waste Gas ▿ †

    Science.gov (United States)

    Köpke, Michael; Mihalcea, Christophe; Liew, FungMin; Tizard, Joseph H.; Ali, Mohammed S.; Conolly, Joshua J.; Al-Sinawi, Bakir; Simpson, Séan D.

    2011-01-01

    2,3-Butanediol (23BD) is a high-value chemical usually produced petrochemically but which can also be synthesized by some bacteria. To date, the best microbial 23BD production rates have been observed using pathogenic bacteria in fermentation systems that depend on sugars as the carbon and energy sources for product synthesis. Here we present evidence of 23BD production by three nonpathogenic acetogenic Clostridium species—Clostridium autoethanogenum, C. ljungdahlii, and C. ragsdalei—using carbon monoxide-containing industrial waste gases or syngas as the sole source of carbon and energy. Through an analysis of the C. ljungdahlii genome, the complete pathway from carbon monoxide to 23BD has been proposed. Homologues of the genes involved in this pathway were also confirmed for the other two species investigated. A gene expression study demonstrates a correlation between mRNA accumulation from 23BD biosynthetic genes and the onset of 23BD production, while a broader expression study of Wood-Ljungdahl pathway genes provides a transcription-level view of one of the oldest existing biochemical pathways. PMID:21685168

  10. Survey on the trend of coal liquefaction/gasification technologies, broken down by application; Sekitan no ekika gas ka no yotobetsu gijutsu no doko chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1983-03-01

    To drive forward the development of the above-named technologies efficiently and effectively, it is necessary to clearly define what coal derived products will meet the need of the clientele and to develop coal derived products accordingly. This survey aims to disclose the whole pictures of the oil/gas using areas and enable the study and evaluation of the possibilities of using coal derived products as substitutes in every one of the expected applications. It also aims to clarify product characteristics, use conditions, technical tasks, and problems to accompany actual substitution in the applications where possibilities are high of their serving as substitutes. Chapter 1, explaining the trend of coal liquefaction/gasification technologies, describes projects for the development of coal liquefaction/gasification technologies, trend of the development of coal liquefaction/gasification technologies, and properties of coal liquefaction/gasification products. Chapter 2, explaining the trend of demand for energy for use in the respective applications, analyzes the trend of demands for oil products, gases, and methanol. Chapter 3 summarizes the applications of chemical materials and fuels for studying the use of coal liquefaction/gasification products as substitutes in the respective applications. Chapter 4 collects problems to solve for the enhancement of coal liquefaction/gasification projects. (NEDO)

  11. Size-controlled synthesis of SnO{sub 2} quantum dots and their gas-sensing performance

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jianping, E-mail: dujp518@163.com [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); Zhao, Ruihua [Shanxi Kunming Tobacco Limited Liability Company, Taiyuan 030012, Shanxi (China); Xie, Yajuan [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); Li, Jinping, E-mail: jpli211@hotmail.com [Research Institute of Special Chemicals, Taiyuan University of Technology, Shanxi, 030024 (China)

    2015-08-15

    Graphical abstract: The gas-sensing property of quantum dots is related to their sizes. SnO{sub 2} quantum dots (TQDs) were synthesized and the sizes were controlled by a simple strategy. The results show that controlling QDs size is efficient to detect low-concentration hazardous volatile compounds selectively. - Highlights: • SnO{sub 2} quantum dots with controllable size were synthesized by hydrothermal route. • The sizes of SnO{sub 2} quantum dots (TQDs) were controlled by a simple strategy. • The responses to volatile chemicals strongly depend on the size of quantum dots. • Small-size TQDs exhibit a good selectivity and response to triethylamine. • Controlling size is efficient to detect low-concentration toxic gases selectively. - Abstract: Tin dioxide quantum dots (TQDs) with controllable size were synthesized by changing the amount of alkaline reagent in the hydrothermal process. The gas-sensing properties were investigated by operating chemoresistor type sensor. The morphology and structure were characterized by X-ray diffraction, scanning/transmission electron microscopy, UV–vis and Raman spectrometry. The as-synthesized SnO{sub 2} shows the characteristics of quantum dots and the narrowest size distribution is about 2–3 nm. The gas-sensing results indicate that the responses are strongly dependent on the size of quantum dots. TQDs with different sizes exhibit different sensitivities and selectivities to volatile toxic chemicals such as aldehyde, acetone, methanol, ethanol and amine. Especially, when the sensors are exposed to 100 ppm triethylamine (TEA), the sensing response value of TQDs with small size is two times higher than that of the large-size TQDs. The maximum response values of TQDs to 1 ppm and 100 ppm TEA are 15 and 153, respectively. The response time is 1 s and the recovery time is 47 s upon exposure to 1 ppm TEA. The results suggest that it is an effective method by regulating the size of SnO{sub 2} quantum dots to detect low

  12. Size-controlled synthesis of SnO2 quantum dots and their gas-sensing performance

    International Nuclear Information System (INIS)

    Du, Jianping; Zhao, Ruihua; Xie, Yajuan; Li, Jinping

    2015-01-01

    Graphical abstract: The gas-sensing property of quantum dots is related to their sizes. SnO 2 quantum dots (TQDs) were synthesized and the sizes were controlled by a simple strategy. The results show that controlling QDs size is efficient to detect low-concentration hazardous volatile compounds selectively. - Highlights: • SnO 2 quantum dots with controllable size were synthesized by hydrothermal route. • The sizes of SnO 2 quantum dots (TQDs) were controlled by a simple strategy. • The responses to volatile chemicals strongly depend on the size of quantum dots. • Small-size TQDs exhibit a good selectivity and response to triethylamine. • Controlling size is efficient to detect low-concentration toxic gases selectively. - Abstract: Tin dioxide quantum dots (TQDs) with controllable size were synthesized by changing the amount of alkaline reagent in the hydrothermal process. The gas-sensing properties were investigated by operating chemoresistor type sensor. The morphology and structure were characterized by X-ray diffraction, scanning/transmission electron microscopy, UV–vis and Raman spectrometry. The as-synthesized SnO 2 shows the characteristics of quantum dots and the narrowest size distribution is about 2–3 nm. The gas-sensing results indicate that the responses are strongly dependent on the size of quantum dots. TQDs with different sizes exhibit different sensitivities and selectivities to volatile toxic chemicals such as aldehyde, acetone, methanol, ethanol and amine. Especially, when the sensors are exposed to 100 ppm triethylamine (TEA), the sensing response value of TQDs with small size is two times higher than that of the large-size TQDs. The maximum response values of TQDs to 1 ppm and 100 ppm TEA are 15 and 153, respectively. The response time is 1 s and the recovery time is 47 s upon exposure to 1 ppm TEA. The results suggest that it is an effective method by regulating the size of SnO 2 quantum dots to detect low-concentration hazardous

  13. Combined plasma gas-phase synthesis and colloidal processing of InP/ZnS core/shell nanocrystals

    Science.gov (United States)

    Gresback, Ryan; Hue, Ryan; Gladfelter, Wayne L.; Kortshagen, Uwe R.

    2011-12-01

    Indium phosphide nanocrystals (InP NCs) with diameters ranging from 2 to 5 nm were synthesized with a scalable, flow-through, nonthermal plasma process at a rate ranging from 10 to 40 mg/h. The NC size is controlled through the plasma operating parameters, with the residence time of the gas in the plasma region strongly influencing the NC size. The NC size distribution is narrow with the standard deviation being less than 20% of the mean NC size. Zinc sulfide (ZnS) shells were grown around the plasma-synthesized InP NCs in a liquid phase reaction. Photoluminescence with quantum yields as high as 15% were observed for the InP/ZnS core-shell NCs.

  14. Synthesis of star-shaped lead sulfide (PbS) nanomaterials and theirs gas-sensing properties

    Energy Technology Data Exchange (ETDEWEB)

    Song, Chengwen; Sun, Menghan; Yin, Yanyan; Xiao, Jingkun; Dong, Wei; Li, Chen; Zhang, Li, E-mail: chengwensong@dlmu.edu.cn [College of Environmental Science and Engineering, Dalian Maritime University, Dalian(China)

    2016-11-15

    Star-shaped PbS nanomaterials are synthesized by a hydrothermal method. Morphology and structure of the PbS nanomaterials are analyzed by SEM, HRTEM and XRD. Gas-sensing properties of the as-prepared PbS sensor are also systematically investigated. The results show star-shaped PbS nanostructure consists of four symmetric arms in the same plane and demonstrate good crystallinity. With the increase of ethanol concentration, the sensitivity of the PbS sensor significantly increases and demonstrates an almost linear relationship at the optimal operating temperature of 400 deg C. Moreover, the fast response-recovery towards ethanol is also observed, which indicates its great potential on ethanol detection. (author)

  15. Krypton Gas for High Quality Single Wall Carbon Nanotubes Synthesis by KrF Excimer Laser Ablation

    Directory of Open Access Journals (Sweden)

    Jasim Al-Zanganawee

    2015-01-01

    Full Text Available We report for the first time the production of single wall carbon nanotubes (SWCNTs by KrF excimer laser ablation method under the krypton gas atmosphere. For the ablation experiment 450 mJ energy and 30 Hz repetition rate KrF excimer laser was used, and the target was prepared with the following composition: 0.6% Ni, 0.6% Co, and 98.8% C (atomic percentage. The ablation product was characterized by confocal Raman microspectroscopy, transmission electron microscopy (TEM, scanning electron microscopy (SEM, and thermogravimetric analysis (TGA. The SWCNTs obtained are a mixture of semiconducting and metallic types with narrow diameters distribution of 1.26 to 1.49 nm, are micrometers long, and contain low amount of graphite and amorphous carbon.

  16. Assesment of the energy quality of the synthesis gas produced from biomass derived fuels conversion: Part I: Liquid Fuels, Ethanol

    International Nuclear Information System (INIS)

    Arteaga Perez, Luis E; Casas, Yannay; Peralta, Luis M; Granda, Daikenel; Prieto, Julio O

    2011-01-01

    The use of biofuels plays an important role to increase the efficiency and energetic safety of the energy processes in the world. The main goal of the present research is to study from the thermodynamics and kinetics the effect of the operational variables on the thermo-conversion processes of biomass derived fuels focused on ethanol reforming. Several models are developed to assess the technological proposals. The minimization of Gibbs free energy is the criterion applied to evaluate the performance of the different alternatives considering the equilibrium constraints. All the models where validated on an experimental data base. The gas composition, HHV and the ratio H2/CO are used as measures for the process efficiency. The operational parameters are studied in a wide range (reactants molar ratio, temperature and oxygen/fuel ratio). (author)

  17. GAS PHASE SYNTHESIS OF (ISO)QUINOLINE AND ITS ROLE IN THE FORMATION OF NUCLEOBASES IN THE INTERSTELLAR MEDIUM

    International Nuclear Information System (INIS)

    Parker, Dorian S. N.; Kaiser, Ralf I.; Kostko, Oleg; Troy, Tyler P.; Ahmed, Musahid; Mebel, Alexander M.; Tielens, Alexander G. G. M.

    2015-01-01

    Nitrogen-substituted polycyclic aromatic hydrocarbons (NPAHs) have been proposed to play a key role in the astrochemical evolution of the interstellar medium, yet the formation mechanisms of even their simplest prototypes—quinoline and isoquinoline—remain elusive. Here, we reveal a novel concept that under high temperature conditions representing circumstellar envelopes of carbon stars, (iso)quinoline can be synthesized via the reaction of pyridyl radicals with two acetylene molecules. The facile gas phase formation of (iso)quinoline in circumstellar envelopes defines a hitherto elusive reaction class synthesizing aromatic structures with embedded nitrogen atoms that are essential building blocks in contemporary biological-structural motifs. Once ejected from circumstellar shells and incorporated into icy interstellar grains in cold molecular clouds, these NPAHs can be functionalized by photo processing forming nucleobase-type structures as sampled in the Murchison meteorite

  18. Synthesis of star-shaped lead sulfide (PbS) nanomaterials and theirs gas-sensing properties

    International Nuclear Information System (INIS)

    Song, Chengwen; Sun, Menghan; Yin, Yanyan; Xiao, Jingkun; Dong, Wei; Li, Chen; Zhang, Li

    2016-01-01

    Star-shaped PbS nanomaterials are synthesized by a hydrothermal method. Morphology and structure of the PbS nanomaterials are analyzed by SEM, HRTEM and XRD. Gas-sensing properties of the as-prepared PbS sensor are also systematically investigated. The results show star-shaped PbS nanostructure consists of four symmetric arms in the same plane and demonstrate good crystallinity. With the increase of ethanol concentration, the sensitivity of the PbS sensor significantly increases and demonstrates an almost linear relationship at the optimal operating temperature of 400 deg C. Moreover, the fast response-recovery towards ethanol is also observed, which indicates its great potential on ethanol detection. (author)

  19. Novel Approaches to the Production of Higher Alcohols From Synthesis Gas. Quarterly report, January 1 - March 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, George W

    1998-12-11

    A modified analytical system was assembled and calibrated, in preparation for a second run with cesium (Cs)-promoted "zinc chromite" catalyst. A new column for the on-line gas chromatography (GC) was purchased for the analysis of various light olefin and paraffin isomers. A run was carried out in the continuous stirred autoclave using the Cs-promoted catalyst. Decahydronaphfialene was used as the slurry liquid. Reaction conditions were 375°C, 2000 psig total pressure, 0.5 H₂/CO ratio, and 5000 sL/Kg (cat.)-hr. Analysis of the data from this run is in progress. A manuscript on the thermal stability of potential slurry liquids was submitted to 'Industrial and Engineering Chemistry Research,' and a paper was presented at the 1997 Spring National Meeting of the American Institute of Chemical Engineers, Houston, Texas.

  20. Synthesis and densification of Cu added Fe-based BMG composite powders by gas atomization and electrical explosion of wire

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.C., E-mail: jckimpml@ulsan.ac.k [University of Ulsan, School of Materials Science and Engineering, Ulsan 680-749 (Korea, Republic of); Ryu, H.J.; Kim, J.S. [University of Ulsan, School of Materials Science and Engineering, Ulsan 680-749 (Korea, Republic of); Kim, B.K.; Kim, Y.J. [Department of Powder Materials, Korea Institute of Materials Science, Changwon 641-831 (Korea, Republic of); Kim, H.J. [Advanced Materials Division, Korea Institute of Industrial Technology, Incheon 406-130 (Korea, Republic of)

    2009-08-26

    In this study, the Fe-based (Fe-C-Si-B-P-Cr-Mo-Al) BMG powders were produced by the high pressure gas atomization process, and they were combined with the ductile Cu powders produced by the electrical explosion of wire (EEW). The Fe-based amorphous powders and Cu added BMG composite powders were compacted by the spark plasma sintering (SPS) processes into cylindrical shape. In the SPS press, the as-prepared powders were sintered at 793 K and 843 K. The relative density increased to 98% when the pressure increased up to 500 MPa by optimum control of the SPS process parameters. The micro-Vickers hardness was over 1100 Hv.

  1. In Situ Synthesis of Al-Based MMCs Reinforced with AlN by Mechanical Alloying under NH3 Gas

    Directory of Open Access Journals (Sweden)

    E. S. Caballero

    2018-05-01

    Full Text Available Aluminum matrix composites (AMCs reinforced by aluminum nitride were prepared by mechanical alloying followed by a simple press and sintering method. Milling began under vacuum and after a period of between 1 and 4 h, NH3 gas flow (1 cm3/s was incorporated until the total milling time of 5 h was reached. Results show that in addition to the strain hardening taking place during mechanical alloying, NH3 plays an additional role in powder hardening. Thereby, the properties of the sintered compacts are strongly influenced by the amount of N incorporated into the powders during milling and the subsequent formation of AlN during the consolidation process. The obtained AMC reaches tensile strengths as high as 459 MPa and hardness much higher than that of the as-received aluminum compact.

  2. Development of Ni-Based Catalysts Derived from Hydrotalcite-Like Compounds Precursors for Synthesis Gas Production via Methane or Ethanol Reforming

    Directory of Open Access Journals (Sweden)

    Ya-Li Du

    2017-02-01

    Full Text Available As a favorably clean fuel, syngas (synthesis gas production has been the focus of concern in past decades. Substantial literatures reported the syngas production by various catalytic reforming reactions particularly in methane or ethanol reforming. Among the developed catalysts in these reforming processes, Ni-based catalysts from hydrotalcite-like compounds (HTLcs precursors have drawn considerable attention for their preferable structural traits. This review covers the recent literature reporting syngas production with Ni-based catalysts from HTLc precursors via methane or ethanol reforming. The discussion was initiated with catalyst preparation (including conventional and novel means, followed by subsequent thermal treatment processes, then composition design and the addition of promoters in these catalysts. As Ni-based catalysts have thermodynamic potential to deactivate because of carbon deposition or metal sintering, measures for dealing with these problems were finally summarized. To obtain optimal catalytic performances and resultantly better syngas production, based on analyzing the achievements of the references, some perspectives were finally proposed.

  3. Synthesis and chlorination of manganese-columbine by means of a solid-gas reaction. Determination of crystalline structures

    International Nuclear Information System (INIS)

    Gonzales, J.; Ruiz, M. del C.

    1997-01-01

    Full text. The synthesis of mangano-columbite was carried out as follows: Mixing of N B 203 and Mn Cl 2 with an 10% weight excess of the latter in order to compensate for losses due to volatilization; grinding of the mixture in an agate mortar with agate handle in order to achieve close contact between the two solids; calcination of the sample in a quartz crucible at temperatures between 610 and 620 C (fusion temperature for Mn Cl2) in N2 current for six hours. After this time, temperature was increased at a eat of 50 C/h until reaching 800 C. This temperature was maintained for two hours in order to eliminate Mn Cl2 excess; cooling of the obtained product in N2 current. XRD analysis showed that the obtained products is a mangano-columbite. The mineral in natural state presents and orthorhombic structure. The structure of the synthesized product, though corresponding to mangano-columbite according to DRX, should be confirmed by means of an additional technique such as EXAFS. Th mangano-columbite obtained was subsequently chlorinated at 900 deg C for two hours to obtain conversions close to 50%, at 101 kPa, with a chlorine molar fraction of 1 and a flow of 50 cm3/min. By XRD it can be observed that the chlorination residue presents unreacted mangano-columbite and niobium oxide in an unknown phase, whose crystalline structure is currently under study. Measurements to be performed by means Synchrotron Radiation (EXAFS and XANES) might help elucidate this new structure. (author)

  4. The influence of N-acetyl-L-cysteine on oxidative stress and nitric oxide synthesis in stimulated macrophages treated with a mustard gas analogue

    Directory of Open Access Journals (Sweden)

    Smith Milton

    2008-06-01

    Full Text Available Abstract Background Sulphur mustard gas, 2, 2'-dichlorodiethyl sulphide (HD, is a chemical warfare agent. Both mustard gas and its monofunctional analogue, 2-chloroethyl ethyl sulphide (CEES, are alkylating agents that react with and diminish cellular thiols and are highly toxic. Previously, we reported that lipopolysaccharide (LPS significantly enhances the cytotoxicity of CEES in murine RAW 264.7 macrophages and that CEES transiently inhibits nitric oxide (NO production via suppression of inducible NO synthase (iNOS protein expression. NO generation is an important factor in wound healing. In this paper, we explored the hypotheses that LPS increases CEES toxicity by increasing oxidative stress and that treatment with N-acetyl-L-cysteine (NAC would block LPS induced oxidative stress and protect against loss of NO production. NAC stimulates glutathione (GSH synthesis and also acts directly as a free radical scavenger. The potential therapeutic use of the antibiotic, polymyxin B, was also evaluated since it binds to LPS and could thereby block the enhancement of CEES toxicity by LPS and also inhibit the secondary infections characteristic of HD/CEES wounds. Results We found that 10 mM NAC, when administered simultaneously or prior to treatment with 500 μM CEES, increased the viability of LPS stimulated macrophages. Surprisingly, NAC failed to protect LPS stimulated macrophages from CEES induced loss of NO production. Macrophages treated with both LPS and CEES show increased oxidative stress parameters (cellular thiol depletion and increased protein carbonyl levels. NAC effectively protected RAW 264.7 cells simultaneously treated with CEES and LPS from GSH loss and oxidative stress. Polymyxin B was found to partially block nitric oxide production and diminish CEES toxicity in LPS-treated macrophages. Conclusion The present study shows that oxidative stress is an important mechanism contributing to CEES toxicity in LPS stimulated macrophages and

  5. Gas-phase synthesis and structure of monomeric ZnOH: a model species for metalloenzymes and catalytic surfaces.

    Science.gov (United States)

    Zack, Lindsay N; Sun, Ming; Bucchino, Matthew P; Clouthier, Dennis J; Ziurys, Lucy M

    2012-02-16

    Monomeric ZnOH has been studied for the first time using millimeter and microwave gas-phase spectroscopy. ZnOH is important in surface processes and at the active site of the enzyme carbonic anhydrase. In the millimeter-wave direct-absorption experiments, ZnOH was synthesized by reacting zinc vapor, produced in a Broida-type oven, with water. In the Fourier-transform microwave measurements, ZnOH was produced in a supersonic jet expansion of CH(3)OH and zinc vapor, created by laser ablation. Multiple rotational transitions of six ZnOH isotopologues in their X(2)A' ground states were measured over the frequency range of 22-482 GHz, and splittings due to fine and hyperfine structure were resolved. An asymmetric top pattern was observed in the spectra, showing that ZnOH is bent, indicative of covalent bonding. From these data, spectroscopic constants and an accurate structure were determined. The Zn-O bond length was found to be similar to that in carbonic anhydrase and other model enzyme systems.

  6. Shape and size controlled synthesis of Au nanorods: H{sub 2}S gas-sensing characterizations and antibacterial application

    Energy Technology Data Exchange (ETDEWEB)

    Lanh, Le Thi [College of Sciences, Hue University, 77 Nguyen Hue, Hue City (Viet Nam); Hoa, Tran Thai, E-mail: trthaihoa@yahoo.com [College of Sciences, Hue University, 77 Nguyen Hue, Hue City (Viet Nam); Cuong, Nguyen Duc [College of Sciences, Hue University, 77 Nguyen Hue, Hue City (Viet Nam); Faculty of Hospitality and Tourism, Hue University, 22 Lam Hoang, Hue City (Viet Nam); Khieu, Dinh Quang [College of Sciences, Hue University, 77 Nguyen Hue, Hue City (Viet Nam); Quang, Duong Tuan [College of Education, Hue University, 34 Le Loi, Hue City (Viet Nam); Van Duy, Nguyen; Hoa, Nguyen Duc [International Training Institute for Materials Science, Hanoi University of Science and Technology, Hanoi (Viet Nam); Van Hieu, Nguyen, E-mail: hieu@itims.edu.vn [International Training Institute for Materials Science, Hanoi University of Science and Technology, Hanoi (Viet Nam)

    2015-06-25

    Highlights: • We have demonstrated a facile method to prepare colloid Au nanorods. • The size and shape of Au nanorods can be controlled via seed-mediated growth method. • The H{sub 2}S gas-sensing properties have been investigated. • The antibacterial application has been conducted. - Abstract: Controlling their size and shape is one of the important issues in the fundamental study and application of colloidal metal nanoparticles. In the current study, different sizes and shapes of Au nanorods were fabricated using a seed-mediated growth method. Material characterization by X-ray diffraction and transmission electron microscopy revealed that the obtained products were made of single-crystal Au nanorods with an average diameter and length of 10 nm and 40 nm, respectively. The Au nanorod-based sensor exhibited significantly high sensitivity and fast response/recovery time to low concentrations (2.5–10 ppm) of H{sub 2}S at temperatures ranging from 300 °C to 400 °C. Additionally, they exhibited antibacterial effect at low concentration. These results suggested that the fabricated Au nanorods have excellent potential for practical application in air pollution monitoring and biomedicine.

  7. Shape and size controlled synthesis of Au nanorods: H2S gas-sensing characterizations and antibacterial application

    International Nuclear Information System (INIS)

    Lanh, Le Thi; Hoa, Tran Thai; Cuong, Nguyen Duc; Khieu, Dinh Quang; Quang, Duong Tuan; Van Duy, Nguyen; Hoa, Nguyen Duc; Van Hieu, Nguyen

    2015-01-01

    Highlights: • We have demonstrated a facile method to prepare colloid Au nanorods. • The size and shape of Au nanorods can be controlled via seed-mediated growth method. • The H 2 S gas-sensing properties have been investigated. • The antibacterial application has been conducted. - Abstract: Controlling their size and shape is one of the important issues in the fundamental study and application of colloidal metal nanoparticles. In the current study, different sizes and shapes of Au nanorods were fabricated using a seed-mediated growth method. Material characterization by X-ray diffraction and transmission electron microscopy revealed that the obtained products were made of single-crystal Au nanorods with an average diameter and length of 10 nm and 40 nm, respectively. The Au nanorod-based sensor exhibited significantly high sensitivity and fast response/recovery time to low concentrations (2.5–10 ppm) of H 2 S at temperatures ranging from 300 °C to 400 °C. Additionally, they exhibited antibacterial effect at low concentration. These results suggested that the fabricated Au nanorods have excellent potential for practical application in air pollution monitoring and biomedicine

  8. Simulation of Synthesis Gas Production from Steam Oxygen Gasification of Colombian Coal Using Aspen Plus®

    Directory of Open Access Journals (Sweden)

    Jorge E. Preciado

    2012-11-01

    Full Text Available A steady state simulation of syngas production from a Steam Oxygen Gasification process using commercial technologies was performed using Aspen Plus®. For the simulation, the average proximate and ultimate compositions of bituminous coal obtained from the Colombian Andean region were employed. The simulation was applied to conduct sensitivity analyses in the O2 to coal mass ratio, coal slurry concentration, WGS operating temperature and WGS steam to dry gas molar ratio (SDG over the key parameters: syngas molar composition, overall CO conversion in the WGS reactors, H2 rich-syngas lower heating value (LHV and thermal efficiency. The achieved information allows the selection of critical operating conditions leading to improve system efficiency and environmental performance. The results indicate that the oxygen to carbon ratio is a key variable as it affects significantly both the LHV and thermal efficiency. Nevertheless, the process becomes almost insensitive to SDG values higher than 2. Finally, a thermal efficiency of 62.6% can be reached. This result corresponds to a slurry solid concentration of 0.65, a WGS process SDG of 0.59, and a LTS reactor operating temperature of 473 K. With these fixed variables, a syngas with H2 molar composition of 92.2% and LHV of 12 MJ Nm−3 was attained.

  9. Gas phase synthesis of core-shell Fe@FeO{sub x} magnetic nanoparticles into fluids

    Energy Technology Data Exchange (ETDEWEB)

    Aktas, Sitki, E-mail: aksitki61@gmail.com; Thornton, Stuart C.; Binns, Chris [University of Leicester, Department of Physics and Astronomy (United Kingdom); Denby, Phil [Ensol As, Nesttun (Norway)

    2016-12-15

    Sorbitol, short chain molecules, have been used to stabilise of Fe@FeO{sub x} nanoparticles produced in the gas phase under the ultra-high vacuum (UHV) conditions. The sorbitol coated Fe@FeO{sub x} nanoparticles produced by our method have a narrow size distribution with a hydrodynamic diameter of 35 nm after NaOH is added to the solution. Magnetisation measurement shows that the magnetic nanoparticles are superparamagnetic at 100 K and demonstrate hysteresis at 5 K with an anisotropy constant of 5.31 × 10{sup 4} J/m{sup 3} (similar to bulk iron). Also, it is shown that sorbitol is only suitable for stabilising the Fe@FeO{sub x} suspensions, and it does not prevent further oxidation of the metallic Fe core. According to MRI measurement, the nanoparticles have a high transverse relaxation rate of 425 mM{sup −1} s{sup −1}.

  10. The effect of heat treatments on the synthesis of acrylamide and its quantification by gas chromatography with a nitrogen-phosphorus detetector

    Directory of Open Access Journals (Sweden)

    Delević Veselin M.

    2016-01-01

    Full Text Available In this paper, the influence of thermal treatment (cooking, baking and frying on the content of acrylamide in potato was followed by gas chromatography with nitrogen - phosphorus detector (GC-NPD. Sample preparation was performed in the conventional manner, applying heat treatment as follows: in boiling water at 110 0C for 30 minutes, by baking in an oven for 30 minutes at 2200 C, and frying in oil for 15 minutes at 250 0C. Quantification of acrylamide are preceded: homogenization of the sample, extraction, and evaporation of the extract. The calibration is performed in the concentration range 0-10 mg/kg and obtained value for R2 was higher than 0,99. Llimit of detection and limit of quantification were determined and obtained values were 0,26 mg/kg and 0,41 mg/kg, respectively. Recovery values were ranged from 102% to 110% and confirmed that metod is accurate. The proposed GC-NPD method is simple, reliable, and accurate for determination of the content of acrylamide in food samples. Obtained results show that the content of acrylamide in potato prepared by heat-cooking were below LOD while for samples trathed by baking or frying were in range from 0,6 mg/kg to 2,7 mg/kg. By comparing the content of acrylamide in potato we concluded that heat treatment has a major impact on the synthesis of acrylamide and it would be desirable to develop a process for the preparation of French fries and potato chips with low or no acrylamide content with textured attractive for consummation.

  11. H/sub 2/S-removal processes for low-Btu coal gas

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, M. S.

    1979-01-01

    Process descriptions are provided for seven methods of removing H/sub 2/S from a low-Btu coal-derived gas. The processes include MDEA, Benfield, Selexol, Sulfinol, Stretford, MERC Iron Oxide, and Molecular Sieve. Each of these processes was selected as representing a particular category of gas treating (e.g., physical solvent systems). The open literature contains over 50 processes for H/sub 2/S removal, of which 35 were briefly characterized in the literature survey. Using a technical evaluation of these 35 processes, 21 were eliminated as unsuitable for the required application. The remaining 14 processes represent six categories of gas treating. A seventh category, low-temperature solid sorption, was subsequently added. The processes were qualitatively compared within their respective categories to select a representative process in each of the seven categories.

  12. Speciality chemicals from synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Lin, J.J.; Knifton, J.F. (Shell Development Company, Houston, TX (USA))

    1992-04-01

    Texaco has undertaken research to investigate the use of carbon monoxide and hydrogen as building blocks for the manufacture of amidocarbonylation products. The amidocarbonylation reaction offers a convenient method to construct two functionalities - amido and carboxylate - simultaneously. Texaco has extended this chemistry to make a variety of speciality chemicals by tailoring cobalt catalysts. Products which have been made including: surface active agents such as the C{sub 14} - C{sub 16} alkyl amidoacids; surfactants; intermediates for sweeteners like aspartame; food additives like glutamic acid; and chelating agents such as polyamidoacids. 20 refs., 10 figs., 1 tab.

  13. Law project on the gas utility modernization and gas industries development. Law project synthesis on the gas utility modernization and gas industries development; Projet de loi relatif a la modernisation du service public du gaz naturel et au developpement des entreprises gazieres.Synthese du projet de loi sur la modernisation du service public du gaz et le developpement des entreprises gazieres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-05-01

    The french government would like to develop a law concerning the gas utility modernization and gas industries development, which completes the today system, more particularly, the law of 1946. This project specifies and comforts the gas utility, it gives to the energy policy tools adapted to the new european context. It helps the natural gas industry to become more competitive. The method chosen by the government is presented and discussed in these three documents. (A.L.B.)

  14. Biochemistry of methyl-coenzyme M reductase: the nickel metalloenzyme that catalyzes the final step in synthesis and the first step in anaerobic oxidation of the greenhouse gas methane.

    Science.gov (United States)

    Ragsdale, Stephen W

    2014-01-01

    Methane, the major component of natural gas, has been in use in human civilization since ancient times as a source of fuel and light. Methanogens are responsible for synthesis of most of the methane found on Earth. The enzyme responsible for catalyzing the chemical step of methanogenesis is methyl-coenzyme M reductase (MCR), a nickel enzyme that contains a tetrapyrrole cofactor called coenzyme F430, which can traverse the Ni(I), (II), and (III) oxidation states. MCR and methanogens are also involved in anaerobic methane oxidation. This review describes structural, kinetic, and computational studies aimed at elucidating the mechanism of MCR. Such studies are expected to impact the many ramifications of methane in our society and environment, including energy production and greenhouse gas warming.

  15. Organic compounds in produced waters from coalbed natural gas wells in the Powder River Basin, Wyoming, USA

    Science.gov (United States)

    Orem, W.H.; Tatu, C.A.; Lerch, H.E.; Rice, C.A.; Bartos, T.T.; Bates, A.L.; Tewalt, S.; Corum, M.D.

    2007-01-01

    The organic composition of produced water samples from coalbed natural gas (CBNG) wells in the Powder River Basin, WY, sampled in 2001 and 2002 are reported as part of a larger study of the potential health and environmental effects of organic compounds derived from coal. The quality of CBNG produced waters is a potential environmental concern and disposal problem for CBNG producers, and no previous studies of organic compounds in CBNG produced water have been published. Organic compounds identified in the produced water samples included: phenols, biphenyls, N-, O-, and S-containing heterocyclic compounds, polycyclic aromatic hydrocarbons (PAHs), aromatic amines, various non-aromatic compounds, and phthalates. Many of the identified organic compounds (phenols, heterocyclic compounds, PAHs) are probably coal-derived. PAHs represented the group of organic compounds most commonly observed. Concentrations of total PAHs ranged up to 23 ??g/L. Concentrations of individual compounds ranged from about 18 to compound concentrations was documented, as two wells with relatively high organic compound contents in produced water in 2001 had much lower concentrations in 2002. In many areas, including the PRB, coal strata provide aquifers for drinking water wells. Organic compounds observed in produced water are also likely present in drinking water supplied from wells in the coal. Some of the organic compounds identified in the produced water samples are potentially toxic, but at the levels measured in these samples are unlikely to have acute health effects. The human health effects of low-level, chronic exposure to coal-derived organic compounds in drinking water are currently unknown. Continuing studies will evaluate possible toxic effects from low level, chronic exposure to coal-derived organic compounds in drinking water supplies.

  16. Gas and Gas Pains

    Science.gov (United States)

    ... to produce gas. Often, relatively simple changes in eating habits can lessen bothersome gas. Certain digestive system disorders, ... such as soda and beer, increase stomach gas. Eating habits, such as eating too quickly, drinking through a ...

  17. Synthesis of ZnO thin film by sol-gel spin coating technique for H2S gas sensing application

    Science.gov (United States)

    Nimbalkar, Amol R.; Patil, Maruti G.

    2017-12-01

    In this present work, zinc oxide (ZnO) thin film synthesized by a simple sol-gel spin coating technique. The structural, morphology, compositional, microstructural, optical, electrical and gas sensing properties of the film were studied by using XRD, FESEM, EDS, XPS, HRTEM, Raman, FTIR and UV-vis techniques. The ZnO thin film shows hexagonal wurtzite structure with a porous structured morphology. Gas sensing performance of synthesized ZnO thin film was tested initially for H2S gas at different operating temperatures as well as concentrations. The maximum gas response is achieved towards H2S gas at 300 °C operating temperature, at 100 ppm gas concentration as compared to other gases like CH3OH, Cl2, NH3, LPG, CH3COCH3, and C2H5OH with a good stability.

  18. Preliminary screening: Technical and economic assessment of synthesis gas to fuels and chemicals with emphasis on the potential for biomass-derived syngas

    Energy Technology Data Exchange (ETDEWEB)

    Spath, P. L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dayton, D. C. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2003-12-01

    This report reviews the many syngas to products processes and summarizes the technology status and description, chemistry, catalysts, reactors, gas cleanliness requirements, process and environmental performances, and economics.

  19. Fischer-Tropsch synthesis : catalysts and chemistry

    NARCIS (Netherlands)

    Loosdrecht, van de J.; Botes, F.G.; Ciobica, I.M.; Ferreira, A.C.; Gibson, P.; Moodley, D.J.; Saib, A.M.; Visagie, J.L.; Weststrate, C.J.; Niemantsverdriet, J.W.; Reedijk, J.; Poeppelmeier, K.

    2013-01-01

    The Fischer–Tropsch synthesis represents a time-tested and fully proven technology for the conversion of synthesis gas (CO + H2) into paraffins, olefins, and oxygenated hydrocarbons. Depending on the origin of the syngas, one speaks of gas-to-liquids, coal-to-liquids, biomass-to-liquids, or

  20. Low carbon renewable natural gas production from coalbeds and implications for carbon capture and storage.

    Science.gov (United States)

    Huang, Zaixing; Sednek, Christine; Urynowicz, Michael A; Guo, Hongguang; Wang, Qiurong; Fallgren, Paul; Jin, Song; Jin, Yan; Igwe, Uche; Li, Shengpin

    2017-09-18

    Isotopic studies have shown that many of the world's coalbed natural gas plays are secondary biogenic in origin, suggesting a potential for gas regeneration through enhanced microbial activities. The generation of biogas through biostimulation and bioaugmentation is limited to the bioavailability of coal-derived compounds and is considered carbon positive. Here we show that plant-derived carbohydrates can be used as alternative substrates for gas generation by the indigenous coal seam microorganisms. The results suggest that coalbeds can act as natural geobioreactors to produce low carbon renewable natural gas, which can be considered carbon neutral, or perhaps even carbon negative depending on the amount of carbon sequestered within the coal. In addition, coal bioavailability is no longer a limiting factor. This approach has the potential of bridging the gap between fossil fuels and renewable energy by utilizing existing coalbed natural gas infrastructure to produce low carbon renewable natural gas and reducing global warming.Coalbeds produce natural gas, which has been observed to be enhanced by in situ microbes. Here, the authors add plant-derived carbohydrates (monosaccharides) to coal seams to be converted by indigenous microbes into natural gas, thus demonstrating a potential low carbon renewable natural gas resource.

  1. Hot gas cleanup test facility for gasification and pressurized combustion. Quarterly technical progress report, July 1--September 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the existing Transport Reactor gas source and Hot Gas Cleanup Units: Carbonizer/Pressurized Circulating Fluidized Bed Gas Source; hot Gas Cleanup Units to mate to all gas streams; and Combustion Gas Turbine. Fuel Cell and associated gas treatment. This expansion to the Hot Gas Cleanup Test Facility is herein referred to as the Power Systems Development Facility (PSDF).

  2. Synthesis of the cactus-like silicon nanowires/tungsten oxide nanowires composite for room-temperature NO{sub 2} gas sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weiyi, E-mail: zhangweiyi@tju.edu.cn [School of Electronic Information Engineering, Tianjin University, Tianjin, 300072 (China); Hu, Ming [School of Electronic Information Engineering, Tianjin University, Tianjin, 300072 (China); Key Laboratory for Advanced Ceramics and Machining Technology, Ministry of Education, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Liu, Xing; Wei, Yulong; Li, Na [School of Electronic Information Engineering, Tianjin University, Tianjin, 300072 (China); Qin, Yuxiang, E-mail: qinyuxiang@tju.edu.cn [School of Electronic Information Engineering, Tianjin University, Tianjin, 300072 (China); Key Laboratory for Advanced Ceramics and Machining Technology, Ministry of Education, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2016-09-15

    In the present work, the tungsten oxide (WO{sub 3}) nanowires functionalized silicon nanowires (SiNWs) with cactus-like structure has been successfully synthesized for room-temperature NO{sub 2} detection. The novel nanocomposite was fabricated by metal-assisted chemical etching (MACE) and thermal annealing of tungsten film. The WO{sub 3} nanowires were evenly distributed from the upper to the lower part of the SiNWs, indicating excellent uniformity which is conducive to adsorption and desorption of gas molecules. The gas-sensing properties have been examined by measuring the resistance change towards 0.25–5 ppm NO{sub 2} gas. At room temperature, which is the optimum working temperature, the SiNWs/WO{sub 3} nanowires composite showed two-times higher NO{sub 2} response than that of the bare SiNWs at 2 ppm NO{sub 2}. On the contrary, the responses of composite sensors to high concentrations of other reducing gases were very low, indicating excellent selectivity. Simultaneously, the composite sensors exhibited good sensing repeatability and stability. The enhancement in gas sensing properties may be attributed to the change in width of the space charge region, which is similar to the behavior of p-n junctions under forward bias, in the high-density p-n heterojunction structure formed between SiNWs and WO{sub 3} nanowires. - Highlights: • SiNWs/WO{sub 3} nanowires composite with cactus-like structure is synthesized. • The morphology of WO{sub 3} nanowires depends on the thermal annealing temperature. • The nanocomposite sensor exhibit better gas response than that of bare SiNWs. • The gas sensing mechanism is discussed using p-n heterojunction theory.

  3. Evaluation of Ultra Clean Fuels from Natural Gas

    Energy Technology Data Exchange (ETDEWEB)

    Robert Abbott; Edward Casey; Etop Esen; Douglas Smith; Bruce Burke; Binh Nguyen; Samuel Tam; Paul Worhach; Mahabubul Alam; Juhun Song; James Szybist; Ragini Acharya; Vince Zello; David Morris; Patrick Flynn; Stephen Kirby; Krishan Bhatia; Jeff Gonder; Yun Wang; Wenpeng Liu; Hua Meng; Subramani Velu; Jian-Ping Shen, Weidong Gu; Elise Bickford; Chunshan Song; Chao-Yang Wang; Andre' Boehman

    2006-02-28

    applicable to coal-derived FT liquid fuels. After different gas clean up processes steps, the coal-derived syngas will produce FT liquid fuels that have similar properties to natural gas derived FT liquids.

  4. Advanced IGCC/Hydrogen Gas Turbine Development

    Energy Technology Data Exchange (ETDEWEB)

    York, William [General Electric Company, Schenectady, NY (United States); Hughes, Michael [General Electric Company, Schenectady, NY (United States); Berry, Jonathan [General Electric Company, Schenectady, NY (United States); Russell, Tamara [General Electric Company, Schenectady, NY (United States); Lau, Y. C. [General Electric Company, Schenectady, NY (United States); Liu, Shan [General Electric Company, Schenectady, NY (United States); Arnett, Michael [General Electric Company, Schenectady, NY (United States); Peck, Arthur [General Electric Company, Schenectady, NY (United States); Tralshawala, Nilesh [General Electric Company, Schenectady, NY (United States); Weber, Joseph [General Electric Company, Schenectady, NY (United States); Benjamin, Marc [General Electric Company, Schenectady, NY (United States); Iduate, Michelle [General Electric Company, Schenectady, NY (United States); Kittleson, Jacob [General Electric Company, Schenectady, NY (United States); Garcia-Crespo, Andres [General Electric Company, Schenectady, NY (United States); Delvaux, John [General Electric Company, Schenectady, NY (United States); Casanova, Fernando [General Electric Company, Schenectady, NY (United States); Lacy, Ben [General Electric Company, Schenectady, NY (United States); Brzek, Brian [General Electric Company, Schenectady, NY (United States); Wolfe, Chris [General Electric Company, Schenectady, NY (United States); Palafox, Pepe [General Electric Company, Schenectady, NY (United States); Ding, Ben [General Electric Company, Schenectady, NY (United States); Badding, Bruce [General Electric Company, Schenectady, NY (United States); McDuffie, Dwayne [General Electric Company, Schenectady, NY (United States); Zemsky, Christine [General Electric Company, Schenectady, NY (United States)

    2015-07-30

    The objective of this program was to develop the technologies required for a fuel flexible (coal derived hydrogen or syngas) gas turbine for IGCC that met DOE turbine performance goals. The overall DOE Advanced Power System goal was to conduct the research and development (R&D) necessary to produce coal-based IGCC power systems with high efficiency, near-zero emissions, and competitive capital cost. To meet this goal, the DOE Fossil Energy Turbine Program had as an interim objective of 2 to 3 percentage points improvement in combined cycle (CC) efficiency. The final goal is 3 to 5 percentage points improvement in CC efficiency above the state of the art for CC turbines in IGCC applications at the time the program started. The efficiency goals were for NOx emissions of less than 2 ppm NOx (@15 % O2). As a result of the technologies developed under this program, the DOE goals were exceeded with a projected 8 point efficiency improvement. In addition, a new combustion technology was conceived of and developed to overcome the challenges of burning hydrogen and achieving the DOE’s NOx goal. This report also covers the developments under the ARRA-funded portion of the program that include gas turbine technology advancements for improvement in the efficiency, emissions, and cost performance of gas turbines for industrial applications with carbon capture and sequestration. Example applications could be cement plants, chemical plants, refineries, steel and aluminum plants, manufacturing facilities, etc. The DOE’s goal for more than 5 percentage point improvement in efficiency was met with cycle analyses performed for representative IGCC Steel Mill and IGCC Refinery applications. Technologies were developed in this program under the following areas: combustion, larger latter stage buckets, CMC and EBC, advanced materials and coatings, advanced configurations to reduce cooling, sealing and rotor purge flows, turbine aerodynamics, advanced sensors, advancements in first

  5. Improved sensitivity and selectivity of pristine zinc oxide nanostructures to H2S gas: Detailed study on the synthesis reaction time

    CSIR Research Space (South Africa)

    Motaung, David E

    2016-11-01

    Full Text Available The gas sensing properties of ZnO nanostructures synthesized at various reaction times are reported in this study. The response of ZnO nanostructures to H(sub2), NH(sub3), H(sub2)S and NO(sub2) gases was investigated at different operating...

  6. Synthesis, characterization and performance of NiMo catalysts supported on titania modified alumina for the hydroprocessing of different gas oils derived from Athabasca bitumen

    Energy Technology Data Exchange (ETDEWEB)

    Ferdous, D.; Bakhshi, N.N.; Dalai, A.K. [Catalysis and Chemical Reactor Engineering Laboratories, Department of Chemical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Sask. (Canada); Adjaye, J. [Syncrude Canada Ltd., Edmonton Research Center, No. 9421, 17th Avenue, Edmonton, Alta. (Canada)

    2007-03-08

    In this work, a series of NiMo/Al{sub 2}O{sub 3} catalyst was prepared using different Al{sub 2}O{sub 3} supports modified by titania (0-9 wt%). All modified supports and fresh catalysts were characterized by BET surface area, pore volume and pore diameter measurement, TPR, TPD, XRD, FTIR and Raman spectroscopy analyses. The initial activity of these catalysts were tested in a trickle-bed reactor using three different gas oils such as light gas oil (LGO), blended gas oil (blended: 50% LGO and 50% HGO) and heavy gas oil (HGO), all derived from Athabasca bitumen. Little structural change in alumina was observed with the incorporation of titania. XRD analysis showed the well dispersion of Ni and Mo on the support. Titania in alumina increased the formation of polymolybdenum oxide on the catalyst as evident from TPR and Raman analyses. Weak-intermediate-strong acid sites on the catalyst were observed at all titania concentrations. The Lewis and Bronsted acidity on the catalyst surface increased with the increase in titania concentration from 0 to 9 wt%. Nitrogen conversion increased from 57 to 71 wt%, from 83 to 93 wt% and from 75 to 80 wt% for LGO, blended and HGO, respectively and also sulfur conversion of LGO increased from 86 to 92 wt% when titania concentration was increased from 0 to 9 wt%. For blended and HGO, sulfur conversion was in the range 96-99 wt% at all titania concentrations. (author)

  7. Facile Synthesis of a Hydroxyl-Functionalized Tröger’s Base Diamine: A New Building Block for High-Performance Polyimide Gas Separation Membranes

    KAUST Repository

    Ma, Xiaohua; Abdul Hamid, Mahmoud; Miao, Xiaohe; Pinnau, Ingo

    2017-01-01

    the highest gas-pair permselectivity values of all reported OH-functionalized PIM-PIs to date. The high permselectivity of 6FDA-HTB resulted primarily from exceptional diffusion selectivity due to strong size-sieving properties caused by hydrogen bonding

  8. Controllable synthesis of Co3O4/polyethyleneimine-carbon nanotubes nanocomposites for CO and NH3 gas sensing at room temperature

    International Nuclear Information System (INIS)

    Lin, Yufei; Kan, Kan; Song, Wanzhen; Zhang, Guo; Dang, Lifang; Xie, Yu; Shen, Peikang; Li, Li; Shi, Keying

    2015-01-01

    Graphical abstract: Co 3 O 4 /polyethyleneimine-carbon nanotubes composites (CoPCNTs) have been successfully controllable synthesized via hydrothermal method at different temperature. The CoPCNTs sensors exhibited the highest response to CO and NH 3 gases with response time of 4 s and 4.3 s, low detection limit of 5 ppm and 1 ppm at room temperature, respectively. The enhanced gas sensing could be ascribed to the synergistic effect between the tiny size of Co 3 O 4 and good conductivity of carbon nanotubes functionalized by polyethyleneimine. - Highlights: • The CNTs functionalized by polyethyleneimine provided a new functional structural. • The novel 1D structure could capture and migrate electrons quickly. • The Co 3 O 4 nanoparticles liked a snake winding around CNTs. • The gas sensor could work at room temperatures, which suit to practical application. - Abstract: A novel 1D Co 3 O 4 /polyethyleneimine-carbon nanotubes composites (CoPCNTs) have been successfully synthesized via hydrothermal method at different temperature. The CNTs functionalized by polyethyleneimine (PCNTs) provided a new material with new structural and functional properties. The PCNTs was used as loading guider and electron transfer path. The Co 3 O 4 nanoparticles (NPs) loaded on the PCNTs surface liked a snake winding around CNTs, and the size was about 5–10 nm. The gas sensing characteristics of the CoPCNTs sensors to carbon monoxide (CO) and ammonia (NH 3 ) were evaluated with different gas concentration. The CoPCNTs sensors grown at 160 °C exhibited the highest response to CO and NH 3 gases with response time of 4 s and 4.3 s at room temperature (RT), respectively. Hence, the approach developed in this work would be important for the low-cost and large-scale production of the CoPCNTs materials with highly promising applications in gas sensors

  9. Advanced Acid Gas Separation Technology for Clean Power and Syngas Applications

    Energy Technology Data Exchange (ETDEWEB)

    Amy, Fabrice [Air Products and Chemicals Inc., Allentown, PA (United States); Hufton, Jeffrey [Air Products and Chemicals Inc., Allentown, PA (United States); Bhadra, Shubhra [Air Products and Chemicals Inc., Allentown, PA (United States); Weist, Edward [Air Products and Chemicals Inc., Allentown, PA (United States); Lau, Garret [Air Products and Chemicals Inc., Allentown, PA (United States); Jonas, Gordon [Air Products and Chemicals Inc., Allentown, PA (United States)

    2015-06-30

    Air Products has developed an acid gas removal technology based on adsorption (Sour PSA) that favorably compares with incumbent AGR technologies. During this DOE-sponsored study, Air Products has been able to increase the Sour PSA technology readiness level by successfully operating a two-bed test system on coal-derived sour syngas at the NCCC, validating the lifetime and performance of the adsorbent material. Both proprietary simulation and data obtained during the testing at NCCC were used to further refine the estimate of the performance of the Sour PSA technology when expanded to a commercial scale. In-house experiments on sweet syngas combined with simulation work allowed Air Products to develop new PSA cycles that allowed for further reduction in capital expenditure. Finally our techno economic analysis of the use the Sour PSA technology for both IGCC and coal-to-methanol applications suggests significant improvement of the unit cost of electricity and methanol compared to incumbent AGR technologies.

  10. Synthesis and characterization of a microporous 6FDA-polyimide made from a novel carbocyclic pseudo Tröger's base diamine: Effect of bicyclic bridge on gas transport properties

    KAUST Repository

    Abdulhamid, Mahmoud A.

    2017-10-12

    A newly designed carbocyclic pseudo Tröger\\'s base diamine (CTB) monomer, 2,8-dimethyl-3,9-diamino-5,6,11,12-tetrahydro-5,11-methanodibenzo[a,e][8]annulene (CTBDA) and its isomeric analogue 2,8-dimethyl-(1,7)(4,10)(3,9)-diamino-5,6,11,12-tetrahydro-5,11-methanodibenzo[a,e][8]annulene (iCTBDA), were designed for the synthesis of microporous 6FDA-based polyimides (6FDA-CTBDA and 6FDA-iCTBDA). Both polyimides were soluble, exhibited excellent thermal stability of ∼490 °C, and had high surface areas of 587 m2 g−1 (6FDA-CTBDA) and 562 m2 g−1 (6FDA-iCTBDA). A 6FDA-based polyimide derived from 4,10-dimethyl-3,9-diamino-6H,12H-5,11-methanodibenzo[b,f][1,5]-diazocine (6FDA-TBDA) was made for comparison to investigate the effects of the basic tertiary nitrogen functionality in the Tröger\\'s base diamine on the polymer properties relative to the carbocyclic 6FDA-CTBDA analogue. 6FDA-TBDA displayed lower gas permeabilities but moderately higher gas-pair permselectivities than 6FDA-CTBDA. The enhanced permselectivity of 6FDA-TBDA resulted exclusively from higher diffusion-based selectivity. Direct gas sorption measurements demonstrated that the basicity in the Tröger\\'s base bridge moiety enhanced the sorption capacity of CO2 only slightly and had no effect on the CO2/CH4 solubility selectivity in 6FDA-TBDA vs. 6FDA-CTBDA.

  11. Quinoline derivative containing monomeric and polymeric metal carboxylates: Synthesis, crystal structure and gas adsorption study over a 2D layered framework

    Science.gov (United States)

    Gayen, Saikat; Saha, Debraj; Koner, Subratanath

    2018-06-01

    A new supramolecular metal-carboxylate framework [Co(mqc)2]n (1), and another monomeric compound [Zn (mqc)2(H2O)] (2) (mqcH = 4-methoxy 2-quinolinecarboxylic acid) have been synthesized solvothermally and characterized by single crystal X-ray diffraction, elemental analysis, IR spectra, UV-vis spectra, powdered X-ray diffraction (PXRD) and thermogravimetric analysis. Compound 1 is a 2D coordination polymer, extended to a 3D porous supramolecular network having void space in between 2D layers. Compound 1 exhibits gas uptake capacity of N2, H2, CO2 and CH4 like small gas molecules in which moderately high uptake of H2 and CO2 takes place among the 2D MOFs. While the Zn variety, compound 2 features a one-dimensional chain like structure through strong intermolecular hydrogen-bonding.

  12. Relaxation phenomena in dense gas separation membranes

    NARCIS (Netherlands)

    Wessling, Matthias

    1993-01-01

    Solution-diffusion membranes are widely used for the separation of gaseous and liquid mixtures. The separation of air (O2/N2), landfill gas (CH4/CO2) and purge gas streams (NH3/H2) in the ammonia synthesis are examples for state-of-the-art membrane gas separation processes. For the separation of

  13. Novel 6FDA-based polyimides derived from sterically hindered Tröger's base diamines: Synthesis and gas permeation properties

    KAUST Repository

    Ghanem, Bader

    2016-04-30

    Two novel Tröger\\'s base-based di-o-substituted diamine monomers were synthesized and used to prepare two intrinsically microporous 6FDA-based polyimides (PIM-PI-TB-1 and PIM-PI-TB-2) with high molecular weight, high thermal stability and excellent solubility in common organic solvents. Compared to previously reported methods for preparing TB-based diamines, which are based on reduction of dimerized nitro-substituted anilines or condensation of phenylenediamine derivatives with dianhydrides, the novel protocol can be used to prepare different functionalized TB-based diamine monomers from a wide variety of aniline derivatives. PIM-PI-TB-1 (made from 6FDA and dibromo-tetramethyl-substituted TB diamine) and PIM-PI-TB-2 (made from 6FDA and tetramethyl-substituted TB diamine) are intrinsically microporous polymers with high BET surface areas of 440 m2/g and 580 m2/g, respectively. Pure-gas permeability coefficients of He, H2, N2, O2, CH4, and CO2 were measured at 35 °C and 2 bar for fresh and 180 days aged films. Both TB-based polyimides exhibited high gas permeability with moderate selectivity. The gas permeability dropped significantly coupled with a moderate increase in selectivity after long-term physical aging of 180 days.

  14. Hydrothermal synthesis of p-type nanocrystalline NiO nanoplates for high response and low concentration hydrogen gas sensor application

    KAUST Repository

    Nakate, Umesh T.; Lee, Gun Hee; Ahmad, Rafiq; Patil, Pramila; Bhopate, Dhanaji P.; Hahn, Y.B.; Yu, Y.T.; Suh, Eun-kyung

    2018-01-01

    High quality nanocrystalline NiO nanoplates were synthesized using surfactant and template free hydrothermal route. The gas sensing properties of NiO nanoplates were investigated. The nanoplates morphology of NiO with average thickness ~20 nm and diameter ~100 nm has been confirmed by FE-SEM and TEM. Crystalline quality of NiO has been studied using HRTEM and SAED techniques. Structural properties and elemental compositions have been analysed by XRD and energy dispersive spectrometer (EDS) respectively. The detailed investigation of structural parameters has been carried out. The optical properties of NiO were analyzed from UV-Visible and photoluminescence spectra. NiO nanoplates have good selectivity towards hydrogen (H2) gas. The lowest H2 response of 3% was observed at 2 ppm, whereas 90% response was noted for 100 ppm at optimized temperature of 200 °C with response time 180 s. The H2 responses as functions of different operating temperature as well as gas concentrations have been studied along with sensor stability. The hydrogen sensing mechanism was also elucidated.

  15. Hydrothermal synthesis of p-type nanocrystalline NiO nanoplates for high response and low concentration hydrogen gas sensor application

    KAUST Repository

    Nakate, Umesh T.

    2018-05-30

    High quality nanocrystalline NiO nanoplates were synthesized using surfactant and template free hydrothermal route. The gas sensing properties of NiO nanoplates were investigated. The nanoplates morphology of NiO with average thickness ~20 nm and diameter ~100 nm has been confirmed by FE-SEM and TEM. Crystalline quality of NiO has been studied using HRTEM and SAED techniques. Structural properties and elemental compositions have been analysed by XRD and energy dispersive spectrometer (EDS) respectively. The detailed investigation of structural parameters has been carried out. The optical properties of NiO were analyzed from UV-Visible and photoluminescence spectra. NiO nanoplates have good selectivity towards hydrogen (H2) gas. The lowest H2 response of 3% was observed at 2 ppm, whereas 90% response was noted for 100 ppm at optimized temperature of 200 °C with response time 180 s. The H2 responses as functions of different operating temperature as well as gas concentrations have been studied along with sensor stability. The hydrogen sensing mechanism was also elucidated.

  16. Novel 6FDA-based polyimides derived from sterically hindered Tröger's base diamines: Synthesis and gas permeation properties

    KAUST Repository

    Ghanem, Bader; Alaslai, Nasser Y.; Miao, Xiaohe; Pinnau, Ingo

    2016-01-01

    Two novel Tröger's base-based di-o-substituted diamine monomers were synthesized and used to prepare two intrinsically microporous 6FDA-based polyimides (PIM-PI-TB-1 and PIM-PI-TB-2) with high molecular weight, high thermal stability and excellent solubility in common organic solvents. Compared to previously reported methods for preparing TB-based diamines, which are based on reduction of dimerized nitro-substituted anilines or condensation of phenylenediamine derivatives with dianhydrides, the novel protocol can be used to prepare different functionalized TB-based diamine monomers from a wide variety of aniline derivatives. PIM-PI-TB-1 (made from 6FDA and dibromo-tetramethyl-substituted TB diamine) and PIM-PI-TB-2 (made from 6FDA and tetramethyl-substituted TB diamine) are intrinsically microporous polymers with high BET surface areas of 440 m2/g and 580 m2/g, respectively. Pure-gas permeability coefficients of He, H2, N2, O2, CH4, and CO2 were measured at 35 °C and 2 bar for fresh and 180 days aged films. Both TB-based polyimides exhibited high gas permeability with moderate selectivity. The gas permeability dropped significantly coupled with a moderate increase in selectivity after long-term physical aging of 180 days.

  17. Controllable synthesis of Co{sub 3}O{sub 4}/polyethyleneimine-carbon nanotubes nanocomposites for CO and NH{sub 3} gas sensing at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yufei [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Kan, Kan [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin 150000 (China); Song, Wanzhen; Zhang, Guo; Dang, Lifang [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Xie, Yu [Department of Materials Chemistry, Nanchang Hangkong University, Nanchang 330063 (China); Shen, Peikang [Department of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Li, Li, E-mail: llwjjhlju@sina.cn [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Key Laboratory of Chemical Engineering Process & Technology for High-efficiency Conversion, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Shi, Keying, E-mail: shikeying2008@163.com [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China)

    2015-08-05

    Graphical abstract: Co{sub 3}O{sub 4}/polyethyleneimine-carbon nanotubes composites (CoPCNTs) have been successfully controllable synthesized via hydrothermal method at different temperature. The CoPCNTs sensors exhibited the highest response to CO and NH{sub 3} gases with response time of 4 s and 4.3 s, low detection limit of 5 ppm and 1 ppm at room temperature, respectively. The enhanced gas sensing could be ascribed to the synergistic effect between the tiny size of Co{sub 3}O{sub 4} and good conductivity of carbon nanotubes functionalized by polyethyleneimine. - Highlights: • The CNTs functionalized by polyethyleneimine provided a new functional structural. • The novel 1D structure could capture and migrate electrons quickly. • The Co{sub 3}O{sub 4} nanoparticles liked a snake winding around CNTs. • The gas sensor could work at room temperatures, which suit to practical application. - Abstract: A novel 1D Co{sub 3}O{sub 4}/polyethyleneimine-carbon nanotubes composites (CoPCNTs) have been successfully synthesized via hydrothermal method at different temperature. The CNTs functionalized by polyethyleneimine (PCNTs) provided a new material with new structural and functional properties. The PCNTs was used as loading guider and electron transfer path. The Co{sub 3}O{sub 4} nanoparticles (NPs) loaded on the PCNTs surface liked a snake winding around CNTs, and the size was about 5–10 nm. The gas sensing characteristics of the CoPCNTs sensors to carbon monoxide (CO) and ammonia (NH{sub 3}) were evaluated with different gas concentration. The CoPCNTs sensors grown at 160 °C exhibited the highest response to CO and NH{sub 3} gases with response time of 4 s and 4.3 s at room temperature (RT), respectively. Hence, the approach developed in this work would be important for the low-cost and large-scale production of the CoPCNTs materials with highly promising applications in gas sensors.

  18. Integrated methanol synthesis

    International Nuclear Information System (INIS)

    Jaeger, W.

    1982-01-01

    This invention concerns a plant for methanol manufacture from gasified coal, particularly using nuclear power. In order to reduce the cost of the hydrogen circuits, the methanol synthesis is integrated in the coal gasification plant. The coal used is gasified with hydration by means of hydrogen and the crude gas emerging, after cooling and separating the carbon dioxide and hydrogen sulphide, is mixed with the synthetic gas leaving the methane cracking furnace. This mixture is taken to the methanol synthesis and more than 90% is converted into methanol in one pass. The gas mixture remaning after condensation and separation of methanol is decomposed into three fractions in low temperature gas decomposition with a high proportion of unconverted carbon monoxide. The flow of methane is taken to the cracking furnace with steam, the flow of hydrogen is taken to the hydrating coal gasifier, and the flow of carbon monoxide is taken to the methanol synthesis. The heat required for cracking the methane can either be provided by a nuclear reactor or by the coke left after hydrating gasification. (orig./RB) [de

  19. Catalytic hydrotreatment of coal-derived naphtha using commercial catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Liaw, S.-J.; Keogh, R.A.; Thomas, G.A.; Davis, B.H. (University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research)

    Naphtha samples derived from the liquefaction of a bituminous Illinois No. 6 and a subbituminous Black Thunder coal were hydrotreated using commercial Co-Mo/Al[sub 2]O[sub 3], Ni-Mo/Al[sub 2]O[sub 3], and Ni-W/Al[sub 2]O[sub 3] catalysts. It was easier to remove the N, O and S heteroatoms from Illinois No. 6 naphtha than from the Black Thunder naphtha. Nitrogen and oxygen were more difficult to remove than sulfur in the temperature range 200-400[degree]C. Considerable differences in catalyst activity for the hydrodenitrogenation (HDN), hydrodeoxygenation (HDO), and hydrodesulfurization (HDS) reactions were observed. The Ni-Mo catalyst was found to be the most active catalyst for the HDN and HDO reactions and the least active catalyst for the HDS. The Co-Mo catalyst was the most active catalyst for the sulfur removal. For the Illinois No. 6 naphtha, a first-order reaction applies for the HDN and HDO reactions for all three catalysts. However, for the Black Thunder naphtha, the first-order reaction applies only at the lower space velocities; a large deviation is observed at higher space velocities. 11 refs., 15 figs., 4 tabs.

  20. Innovation avenues for coal derived power essential for the future

    Energy Technology Data Exchange (ETDEWEB)

    Berkley, Mark; Cruz, Elizabet; Vatanakul, Maytinee; Hynes, Rory; Stickler, Alexander

    2010-09-15

    Current political climates are culminating in the conflict between economic development and environmental regulation -- Climate Change. Developed nations are driven by and dependent upon the cheap, abundant power of coal. Today, developing nations wish to duplicate this historical pathway, yet are subject to global scrutiny. The politico-economic conflict between nations may be alleviated by innovative technologies delivering power and improved environmental considerations. The long-term economic trend has been upward and thus targeting expanding and converting existing economies to utilize innovative technologies is fundamental to addressing the balance between socio-economic and environmental interests.

  1. Synthesis, characterization and formaldehyde gas sensitivity of La{sub 0.7}Sr{sub 0.3}FeO{sub 3} nanoparticles assembled nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Yao Pengjun [School of Electronic Science and Technology, Dalian University of Technology, Dalian 116023 (China); School of Educational Technology, Shenyang Normal University, Shenyang 110034 (China); Wang Jing, E-mail: wangjing@dlut.edu.cn [School of Electronic Science and Technology, Dalian University of Technology, Dalian 116023 (China); Du Haiying [School of Electronic Science and Technology, Dalian University of Technology, Dalian 116023 (China); Department of Electromechanical Engineering and Information, Dalian Nationalities University, Dalian 116600 (China); Qi Jinqing [School of Electronic Science and Technology, Dalian University of Technology, Dalian 116023 (China)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer High aspect ratio La{sub 0.7}Sr{sub 0.3}FeO{sub 3} nanoparticles assembled nanowires were synthesized by a CTAB assisted hydrothermal method. Black-Right-Pointing-Pointer Formaldehyde with low concentration (0.1-100 ppm) was used for gas sensing study. Black-Right-Pointing-Pointer The growth mechanism of La{sub 0.7}Sr{sub 0.3}FeO{sub 3} nanowires was reported. - Abstract: La{sub 0.7}Sr{sub 0.3}FeO{sub 3} nanoparticles assembled nanowires were synthesized by a hydrothermal method assisted with cetyltrimethylammonium bromide (CTAB). The hydrothermal temperature was 180 Degree-Sign C and the annealed temperature was 700 Degree-Sign C. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the morphology, composition and structural properties of the materials. The results showed that the La{sub 0.7}Sr{sub 0.3}FeO{sub 3} nanoparticles assembled nanowires had a high aspect ratio (the largest aspect ratio >100); the size of the nanoparticles was about 20 nm and the diameter of the nanowires was about 100-150 nm. The growth mechanism of La{sub 0.7}Sr{sub 0.3}FeO{sub 3} nanowires was discussed. Gas sensors were fabricated by using La{sub 0.7}Sr{sub 0.3}FeO{sub 3} nanowires. Formaldehyde gas sensing properties were carried out in the concentration range of 0.1-100 ppm at the optimum operating temperature of 280 Degree-Sign C. The response and recovery times to 20 ppm formaldehyde of the sensor were 110 s and 50 s, respectively. The gas sensing mechanism of La{sub 0.7}Sr{sub 0.3}FeO{sub 3} nanowires was investigated.

  2. Synthesis and gas permeation properties of a novel thermally-rearranged polybenzoxazole made from an intrinsically microporous hydroxyl-functionalized triptycene-based polyimide precursor

    KAUST Repository

    Alghunaimi, Fahd; Ghanem, Bader; Wang, Yingge; Salinas, Octavio; Alaslai, Nasser Y.; Pinnau, Ingo

    2017-01-01

    A hydroxyl-functionalized triptycene-based polyimide of intrinsic microporosity (TDA1-APAF) was converted to a polybenzoxazole (PBO) by heat treatment at 460 °C under nitrogen atmosphere. TDA1-APAF treated for 15 min (TR 460) resulted in a PBO conversion of 95% based on a theoretical weight loss of 11.7 wt% of the polyimide precursor. The BET surface area of the TR 460 (680 m2 g−1) was significantly higher than that of the TDA1-APAF polyimide (260 m2 g−1) as determined by nitrogen adsorption at −196 °C. Heating TDA1-APAF for 30 min (TRC 460) resulted in a weight loss of 13.5 wt%, indicating full conversion to PBO and partial main-chain degradation. The TR 460 membrane displayed excellent O2 permeability of 311 Barrer coupled with an O2/N2 selectivity of 5.4 and CO2 permeability of 1328 Barrer with a CO2/CH4 selectivity of 27. Interestingly, physical aging over 150 days resulted in enhanced O2/N2 selectivity of 6.3 with an O2 permeability of 185 Barrer. The novel triptycene-based TR 460 PBO outperformed all previously reported APAF-polyimide-based PBOs with gas permeation performance close to recently reported polymers located on the 2015 O2/N2 upper bound. Based on this study, thermally-rearranged membranes from hydroxyl-functionalized triptycene-based polyimides are promising candidate membrane materials for air separation, specifically in applications where space and weight of membrane systems are of utmost importance such as nitrogen production for inert atmospheres in fuel lines and tanks on aircrafts and off-shore oil- or natural gas platforms. Mixed-gas permeation experiments also demonstrated good performance of the TR 460 membrane for natural gas sweetening with a CO2 permeability of ∼1000 Barrer and CO2/CH4 selectivity of 22 at a typical CO2 wellhead partial pressure of 10 bar.

  3. Synthesis, Crystal Structure, Gas Absorption, and Separation Properties of a Novel Complex Based on Pr and a Three-Connected Ligand

    Directory of Open Access Journals (Sweden)

    Jie Sun

    2017-12-01

    Full Text Available A novel Pr complex, constructed from a rigid three-connected H3TMTA and praseodymium(III ion, has been synthesized in a mixed solvent system and characterized by X-ray single crystal diffraction, infrared spectroscopy, a thermogravimetric analysis, an element analysis, and powder X-ray diffraction, which reveals that complex 1 crystallizes in a three-dimensional porous framework. Moreover, the thermal stabilities and the fluorescent and gas adsorption and separation properties of complex 1 were investigated systematically.

  4. Palladium(II)-Catalysed Aminocarbonylation of Terminal Alkynes for the Synthesis of 2-Ynamides: Addressing the Challenges of Solvents and Gas Mixtures.

    Science.gov (United States)

    Hughes, N Louise; Brown, Clare L; Irwin, Andrew A; Cao, Qun; Muldoon, Mark J

    2017-02-22

    2-Ynamides can be synthesised through Pd II catalysed oxidative carbonylation, utilising low catalyst loadings. A variety of alkynes and amines can be used to afford 2-ynamides in high yields, whilst overcoming the drawbacks associated with previous oxidative methods, which rely on dangerous solvents and gas mixtures. The use of [NBu 4 ]I allows the utilisation of the industrially recommended solvent ethyl acetate. O 2 can be used as the terminal oxidant, and the catalyst can operate under safer conditions with low O 2 concentrations. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Palladium(II)‐Catalysed Aminocarbonylation of Terminal Alkynes for the Synthesis of 2‐Ynamides: Addressing the Challenges of Solvents and Gas Mixtures

    Science.gov (United States)

    Hughes, N. Louise; Brown, Clare L.; Irwin, Andrew A.; Cao, Qun

    2017-01-01

    Abstract 2‐Ynamides can be synthesised through PdII catalysed oxidative carbonylation, utilising low catalyst loadings. A variety of alkynes and amines can be used to afford 2‐ynamides in high yields, whilst overcoming the drawbacks associated with previous oxidative methods, which rely on dangerous solvents and gas mixtures. The use of [NBu4]I allows the utilisation of the industrially recommended solvent ethyl acetate. O2 can be used as the terminal oxidant, and the catalyst can operate under safer conditions with low O2 concentrations. PMID:27906507

  6. Synthesis and gas permeation properties of a novel thermally-rearranged polybenzoxazole made from an intrinsically microporous hydroxyl-functionalized triptycene-based polyimide precursor

    KAUST Repository

    Alghunaimi, Fahd

    2017-06-06

    A hydroxyl-functionalized triptycene-based polyimide of intrinsic microporosity (TDA1-APAF) was converted to a polybenzoxazole (PBO) by heat treatment at 460 °C under nitrogen atmosphere. TDA1-APAF treated for 15 min (TR 460) resulted in a PBO conversion of 95% based on a theoretical weight loss of 11.7 wt% of the polyimide precursor. The BET surface area of the TR 460 (680 m2 g−1) was significantly higher than that of the TDA1-APAF polyimide (260 m2 g−1) as determined by nitrogen adsorption at −196 °C. Heating TDA1-APAF for 30 min (TRC 460) resulted in a weight loss of 13.5 wt%, indicating full conversion to PBO and partial main-chain degradation. The TR 460 membrane displayed excellent O2 permeability of 311 Barrer coupled with an O2/N2 selectivity of 5.4 and CO2 permeability of 1328 Barrer with a CO2/CH4 selectivity of 27. Interestingly, physical aging over 150 days resulted in enhanced O2/N2 selectivity of 6.3 with an O2 permeability of 185 Barrer. The novel triptycene-based TR 460 PBO outperformed all previously reported APAF-polyimide-based PBOs with gas permeation performance close to recently reported polymers located on the 2015 O2/N2 upper bound. Based on this study, thermally-rearranged membranes from hydroxyl-functionalized triptycene-based polyimides are promising candidate membrane materials for air separation, specifically in applications where space and weight of membrane systems are of utmost importance such as nitrogen production for inert atmospheres in fuel lines and tanks on aircrafts and off-shore oil- or natural gas platforms. Mixed-gas permeation experiments also demonstrated good performance of the TR 460 membrane for natural gas sweetening with a CO2 permeability of ∼1000 Barrer and CO2/CH4 selectivity of 22 at a typical CO2 wellhead partial pressure of 10 bar.

  7. Model Catalysis of Ammonia Synthesis ad Iron-Water Interfaces - ASum Frequency Generation Vibrational Spectroscopic Study of Solid-GasInterfaces and Anion Photoelectron Spectroscopic Study of Selected Anionclusters

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, Michael James [Univ. of California, Berkeley, CA (United States)

    2005-01-01

    The ammonia synthesis reaction has been studied using single crystal model catalysis combined with sum frequency generation (SFG) vibrational spectroscopy. The adsorption of gases N2, H2, O2 and NH3 that play a role in ammonia synthesis have been studied on the Fe(111) crystal surface by sum frequency generation vibrational spectroscopy using an integrated Ultra-High Vacuum (UHV)/high-pressure system. SFG spectra are presented for the dissociation intermediates, NH2 (~3325 cm-1) and NH (~3235 cm-1) under high pressure of ammonia or equilibrium concentrations of reactants and products on Fe(111) surfaces. Special attention was paid to understand how potassium promotion of the iron catalyst affects the intermediates of ammonia synthesis. An Fe(111) surface promoted with 0.2 monolayers of potassium red shifts the vibrational frequencies of the reactive surface intermediates, NH and NH2, providing evidence for weakened the nitrogen-hydrogen bonds relative to clean Fe(111). Spectral features of these surface intermediates persisted to higher temperatures for promoted iron surfaces than for clean Fe(111) surfaces implying that nitrogen-iron bonds are stronger for the promoted surface. The ratio of the NH to NH2 signal changed for promoted surfaces in the presence of equilibrium concentrations of reactants and products. The order of adding oxygen and potassium to promoted surfaces does not alter the spectra indicating that ammonia induces surface reconstruction of the catalyst to produce the same surface morphology. When oxygen is co-adsorbed with nitrogen, hydrogen, ammonia or potassium on Fe(111), a relative phase shift of the spectra occurs as compared to the presence of adsorbates on clean iron surfaces. Water adsorption on iron was also probed using SFG vibrational spectroscopy. For both H2O and D2O, the only spectral feature was in the range of

  8. Gas exploitation and gas conversion; Gassutnyttelse og gasskonvertering

    Energy Technology Data Exchange (ETDEWEB)

    Laading, Gjert

    1998-07-01

    This presentation deals with some of the challenges and possibilities connected with ''stranded'' gas. These are offshore gas reserves, especially associated gas, that is not connected with the market and that cannot be piped onshore, and where reinjection is not profitable, and where flaring off is not an option. There is increasing interest all over the world to find economical and environmentally friendly solutions to this problem. A good solution will render such fields economically developable and will to a high degree increase the total volume of the world's exploitable gas reserves. Since synthesis gas is a dominating cost element in most chemical conversion processes for gas, the synthesis gases are discussed in some detail. There is also a discussion of the conversion of the gas to Methanol, Synthetic oil (Syncrude and Synfuels) and to DME (Di-methyl-ether). Two methods for gas transport from the field are discussed; LNG on floating production storage and off loading (FPSO), and Gas hydrates. Principles, limitations and conditions for placing those processes on a FPSO. Finally, the presentation discusses the most important economic factors related to the exploitation of offshore gas, and suggests some possibilities for future development.11 figs.

  9. Synthesis and Enhanced Ethanol Gas Sensing Properties of the g-C3N4 Nanosheets-Decorated Tin Oxide Flower-Like Nanorods Composite

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2017-09-01

    Full Text Available Flower-like SnO2/g-C3N4 nanocomposites were synthesized via a facile hydrothermal method by using SnCl4·5H2O and urea as the precursor. The structure and morphology of the as-synthesized samples were characterized by using the X-ray powder diffraction (XRD, electron microscopy (FESEM and TEM, and Fourier transform infrared spectrometer (FT-IR techniques. SnO2 displays the unique 3D flower-like microstructure assembled with many uniform nanorods with the lengths and diameters of about 400–600 nm and 50–100 nm, respectively. For the SnO2/g-C3N4 composites, SnO2 flower-like nanorods were coupled by a lamellar structure 2D g-C3N4. Gas sensing performance test results indicated that the response of the sensor based on 7 wt. % 2D g-C3N4-decorated SnO2 composite to 500 ppm ethanol vapor was 150 at 340 °C, which was 3.5 times higher than that of the pure flower-like SnO2 nanorods-based sensor. The gas sensing mechanism of the g-C3N4nanosheets-decorated SnO2 flower-like nanorods was discussed in relation to the heterojunction structure between g-C3N4 and SnO2.

  10. The synthesis of porous Co3O4 micro cuboid structures by solvothermal approach and investigation of its gas sensing properties and catalytic activity

    International Nuclear Information System (INIS)

    Jamil, Saba; Jing, Xiaoyan; Wang, Jun; Li, Songnan; Liu, Jingyuan; Zhang, Milin

    2013-01-01

    Graphical abstract: - Highlights: • Micro cuboid Co 3 O 4 particle prepared by solvothermal method. • Study of morphology of synthesized cuboids before and after calcinations. • Investigation of formation mechanism of porous Co 3 O 4 from cuboid CoCO 3 . • Investigation of gas sensing properties of porous Co 3 O 4 . • Study of catalytic activity of product. - Abstract: The cobalt carbonate cuboids are prepared by adopting a simple solvothermal approach by using diethylene glycol and water in specific ratio as solvent. The prepared cobalt carbonate is subjected to different instrumentation to investigate its morphology and other properties. It is clear from the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that the product is distinct cuboid in shape with a size of approximately 3 μm from each face of the cube. Each particle of cuboid cobalt carbonate seems to comprise of layer by layer assembly of unit cells that consequently leads to a cuboid geometry. The cuboid cobalt carbonate was calcined at 700 °C in a furnace under argon atmosphere that decompose cobalt carbonate into porous Co 3 O 4 with the loosely packed arrangement of nano architectures. The gas sensing properties and catalytic activity of porous cuboids Co 3 O 4 are also investigated

  11. Synthesis of Silicalite Membrane with an Aluminum-Containing Surface for Controlled Modification of Zeolitic Pore Entries for Enhanced Gas Separation

    Directory of Open Access Journals (Sweden)

    Shaowei Yang

    2018-02-01

    Full Text Available The separation of small molecule gases by membrane technologies can help performance enhancement and process intensification for emerging advanced fossil energy systems with CO2 capture capacity. This paper reports the demonstration of controlled modification of zeolitic channel size for the MFI-type zeolite membranes to enhance the separation of small molecule gases such as O2 and N2. Pure-silica MFI-type zeolite membranes were synthesized on porous α-alumina disc substrates with and without an aluminum-containing thin skin on the outer surface of zeolite membrane. The membranes were subsequently modified by on-stream catalytic cracking deposition (CCD of molecular silica to reduce the effective openings of the zeolitic channels. Such a pore modification caused the transition of gas permeation from the N2-selective gaseous diffusion mechanism in the pristine membrane to the O2-selective activated diffusion mechanism in the modified membrane. The experimental results indicated that the pore modification could be effectively limited within the aluminum-containing surface of the MFI zeolite membrane to minimize the mass transport resistance for O2 permeation while maintaining its selectivity. The implications of pore modification on the size-exclusion-enabled gas selectivity were discussed based on the kinetic molecular theory. In light of the theoretical analysis, experimental investigation was performed to further enhance the membrane separation selectivity by chemical liquid deposition of silica into the undesirable intercrystalline spaces.

  12. A-few-second synthesis of silicon nanoparticles by gas-evaporation and their self-supporting electrodes based on carbon nanotube matrix for lithium secondary battery anodes

    Science.gov (United States)

    Kowase, Takayuki; Hori, Keisuke; Hasegawa, Kei; Momma, Toshiyuki; Noda, Suguru

    2017-09-01

    Rapid gas-evaporation method is proposed and developed, which yields Si nanoparticles (SiNPs) in a few seconds at high yields of 20%-60% from inexpensive and safe bulk Si. Such rapid process is realized by heating the Si source to a temperature ≥2000 °C, much higher than the melting point of Si (1414 °C). The size of SiNPs is controlled at tens to hundreds nanometers simply by the Ar gas pressure during the evaporation process. Self-supporting films are fabricated simply by co-dispersion and filtration of the SiNPs and carbon nanotubes (CNTs) without using binders nor metal foils. The half-cell tests showed the improved performances of the SiNP-CNT composite films as anode when coated with graphitic carbon layer. Their performances are evaluated with various SiNP sizes and Si/CNT ratios systematically. The SiNP-CNT film with a Si/CNT mass ratio of 4 realizes the balanced film-based capacities of 618 mAh/gfilm, 230 mAh/cm3, and 0.644 mAh/cm2 with a moderate Si-based performance of 863 mAh/gSi at the 100th cycle.

  13. The synthesis of porous Co{sub 3}O{sub 4} micro cuboid structures by solvothermal approach and investigation of its gas sensing properties and catalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, Saba, E-mail: saba_hrb@yahoo.com [Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, Harbin Engineering University, 150001 (China); Jing, Xiaoyan [Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, Harbin Engineering University, 150001 (China); Institute of Advanced Marine Materials, Harbin Engineering University, 150001 (China); Wang, Jun, E-mail: zhqw1888@sohu.com [Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, Harbin Engineering University, 150001 (China); Li, Songnan; Liu, Jingyuan [Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, Harbin Engineering University, 150001 (China); Zhang, Milin [Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, Harbin Engineering University, 150001 (China); Institute of Advanced Marine Materials, Harbin Engineering University, 150001 (China)

    2013-11-15

    Graphical abstract: - Highlights: • Micro cuboid Co{sub 3}O{sub 4} particle prepared by solvothermal method. • Study of morphology of synthesized cuboids before and after calcinations. • Investigation of formation mechanism of porous Co{sub 3}O{sub 4} from cuboid CoCO{sub 3}. • Investigation of gas sensing properties of porous Co{sub 3}O{sub 4}. • Study of catalytic activity of product. - Abstract: The cobalt carbonate cuboids are prepared by adopting a simple solvothermal approach by using diethylene glycol and water in specific ratio as solvent. The prepared cobalt carbonate is subjected to different instrumentation to investigate its morphology and other properties. It is clear from the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that the product is distinct cuboid in shape with a size of approximately 3 μm from each face of the cube. Each particle of cuboid cobalt carbonate seems to comprise of layer by layer assembly of unit cells that consequently leads to a cuboid geometry. The cuboid cobalt carbonate was calcined at 700 °C in a furnace under argon atmosphere that decompose cobalt carbonate into porous Co{sub 3}O{sub 4} with the loosely packed arrangement of nano architectures. The gas sensing properties and catalytic activity of porous cuboids Co{sub 3}O{sub 4} are also investigated.

  14. Gas turbine

    International Nuclear Information System (INIS)

    Yang, Ok Ryong

    2004-01-01

    This book introduces gas turbine cycle explaining general thing of gas turbine, full gas turbine cycle, Ericson cycle and Brayton cycle, practical gas turbine cycle without pressure loss, multiaxial type gas turbine cycle and special gas turbine cycle, application of basic theory on a study on suction-cooling gas turbine cycle with turbo-refrigerating machine using the bleed air, and general performance characteristics of the suction-cooling gas turbine cycle combined with absorption-type refrigerating machine.

  15. Derivatives of 16alpha-hydroxy-dehydroepiandrosterone with an additional 7-oxo or 7-hydroxy substituent: synthesis and gas chromatography/mass spectrometry analysis.

    Science.gov (United States)

    Pouzar, Vladimír; Cerný, Ivan; Hill, Martin; Bicíková, Marie; Hampl, Richard

    2005-10-01

    Derivatives of 16alpha-hydroxy-dehydroepiandrosterone, which have an additional oxygen substituent at position 7 (oxo or hydroxy group), were synthesized. Firstly, 17,17-dimethoxyandrost-5-ene-3beta,16alpha-diyl diacetate was prepared and then oxidized with a complex of chromium(VI) oxide and 2,5-dimethylpyrazole to the respective 7-oxo derivative. This key intermediate was both deprotected or reduced by l-Selectride or sodium borohydride in the presence of cerium(III) chloride and then deprotected to give 7-oxo, 7alpha-hydroxy and 7beta-hydroxy derivatives of 16alpha-hydroxy-dehydroepiandrosterone. The target compounds were characterized by (1)H and (13)C NMR spectra and in the form of O-methyloxime-trimethylsilyl derivatives, by gas chromatography/mass spectrometry methods.

  16. Moessbauer Study of the Ni/Ca0.8Sr0.2Ti1-xFexO3-α Catalyst System for Partial Oxidation of Methane to Synthesis Gas

    International Nuclear Information System (INIS)

    Homonnay, Z.; Nomura, K.; Hamakawa, S.; Hayakawa, T.; Juhasz, G.; Kuzmann, E.; Vertes, A.

    2002-01-01

    The Ni/Ca 0.8 Sr 0.2 TiO 3 catalyst system prepared by the citrate method shows high activity in partial oxidation of methane to synthesis gas. It is assumed that the interaction of Ni with the perovskite lattice may be responsible for the increased catalytic activity. 1% 57 Fe dopant substituted for Ti was used in order to see if the presence of Ni has any perturbation effect on the structure of the perovskite. One may expect systematic changes in the Moessbauer parameters of the substitutional Fe impurity as a function of the NiO content if the bulk properties of the perovskite are affected. Samples with different Ni/Ca 0.8 Sr 0.2 Ti 0.99 57 Fe 0.01 O 3-α ratios from 0:1 to 1:1, and others having Fe substitutions for Ti up to 30%, all prepared by the citrate method, have been investigated. The Moessbauer spectra contained doublets of paramagnetic Fe 3+ and Fe 4+ species as well as paramagnetically relaxed Fe 3+ . These species were assigned to the bulk perovskite, the perovskite surface and the NiO/perovskite interface. The perturbation of the perovskite structure by Ni could not be verified.

  17. Novel Routes to Ethylene Glycol Synthesis via Acid-Catalyzed Carbonylation of Formaldehyde and Dimethoxymethane

    OpenAIRE

    Celik, Fuat Emin

    2010-01-01

    Carbon-carbon bond forming carbonylation reactions were investigated as candidates to replace ethene epoxidation as the major source of ethylene glycol production. This work was motivated by the potentially lower cost of carbon derived from synthesis gas as compared to ethylene. Synthesis gas can be produced from relatively abundant and cheap natural gas, coal, and biomass resources whereas ethylene is derived from increasingly scarce and expensive crude oil. From synthesis gas, a range of...

  18. Optical properties of palladium nanoparticles under exposure of hydrogen and inert gas prepared by dewetting synthesis of thin-sputtered layers

    Energy Technology Data Exchange (ETDEWEB)

    Kracker, Michael, E-mail: Michael.Kracker@uni-jena.de; Worsch, Christian; Ruessel, Christian [Otto-Schott-Institut, Jena University (Germany)

    2013-04-15

    Thin layers of palladium with a thickness of 5 nm were sputtered on fused silica substrates. Subsequently, the coated glasses were annealed at a temperature of 900 Degree-Sign C for 1 h. This resulted in the formation of small and well-separated palladium nanoparticles with diameters in the range from 20 to 200 nm on the glass surface. The existence of a palladium oxide layer can be detected using optical absorption spectroscopy. Purging with hydrogen leads to an irreversible change in the optical spectra due to the reduction of PdO to metallic palladium. Changing the gas atmosphere from hydrogen to argon leads to significant reversible changes in the optical properties of the particle layer. Based on Mie theory and the respective dielectric functions, the spectra were calculated using the real particle size distribution, weighted dispersions relation to adapt the geometrical conditions and complex dielectric functions of palladium and palladium hydride. A good agreement with measured spectra was found and the dependency of the surrounding media can be explained.Graphical Abstract.

  19. ON THE SYNTHESIS OF MOLYBDENUM CARBIDE WITH COBALT ADDITION VIA GAS-SOLID REACTIONS IN A CH4/H2 ATMOSPHERE

    Directory of Open Access Journals (Sweden)

    C. P. B. Araujo

    Full Text Available Abstract Due to ever more severe environmental regulations regarding SOx, NOx and other pollutants' emissions, there has been an interest in developing new and improved catalysts for hydroprocessing reactions. Mo2C has been reported to display good selectivity and activity for those reactions, especially for HDS. Addition of another metal to the carbide structure may improve catalytic properties. Mo2C with low cobalt addition (2.5 and 5% was obtained via gas-solid reaction in a fixed bed reactor with CH4 (5%/H2 atmosphere. XRD and TG/DTA analysis of the precursors were carried out in order to understand its mass loss profile, doping metal presence and phase distributions. CoMoO4 as well as MoO3 were identified after calcining doped precursors at 600 °C/180min. SEM, XRD, XRF, TOC, BET and laser granulometric analysis of the reaction products were also performed. Compositions verified by XRF and theoretical values were compatible. At 700 °C both carbide (Mo2C and oxide (MoO2 phases are present, as identified in XRD analysis and observed by SEM. At 750 °C only single phase Mo2C was verified by XRD, indicating Co dispersion on the carbide matrix. Morphology at this temperature is compatible with pure Mo2C, though XRF indicates Co presence on the material.

  20. Synthesis of Nano sized Zinc-Doped Cobalt Oxyhydroxide Parties by a Dropping Method and Their Carbon Monoxide Gas Sensing Properties

    International Nuclear Information System (INIS)

    Wang, J.W.; Kuo, Y.M.

    2013-01-01

    Two nano structures of cobalt oxyhydroxide (CoOOH) and Zinc-(Zn-) doped CoOOH (1–4% Zn) are prepared from Co(NO 3 ) 2 solution via microtitration with NaOH and oxidation in air. The X-ray diffraction (XRD) analysis results show that a pure state of nano-CoOOH can be obtained at an alkalinity (OH−/Co + ) of 5 with 40°C heat treatment after 6 h. The Zn ions preferentially substitute Co ions in the CoOOH structure, resulting in a decrease of its crystallinity. The disc-like CoOOH nano structure exhibits good sensitivity to carbon monoxide (CO) in a temperature range of 40–110°C with maximum sensitivity to CO at around 70–80°C. When CoOOH nano structure is doped with 1% Zn, its sensitivity and selectivity for CO gas are improved at 70–80°C; further Zn doping to 2% degraded the CO sensing properties of nano-CoOOH. The results of a cross-sensitivity investigation of the sensor to various gases coexisting at early stages of a fire show that the sensitivity of Zn-doped nano-CoOOH is the highest toward CO. Zn-doped nano-CoOOH film exhibits a high sensitivity to CO at room temperature, making it a promising sensor for early-stage fire detection.

  1. Parallel synthesis: a new approach for developing analytical internal standards. Application to the analysis of patulin by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Llovera, Montserrat; Balcells, Mercè; Torres, Mercè; Canela, Ramon

    2005-08-24

    The polymer-assisted reaction of 4-(hydroxymethyl)furan-2(5H)-one (4HM2F) with 21 carboxylic acids using polystyrene-carbodiimide (PS-carbodiimide) yielded an ester library. Four of the esters, (5-oxo-2,5-dihydrofuran-3-yl)methyl acetate (IS-1), (5-oxo-2,5-dihydrofuran-3-yl)methyl butyrate (IS-2), (5-oxo-2,5-dihydrofuran-3-yl)methyl 2-methylpropanoate (IS-3), and (5-oxo-2,5-dihydrofuran-3-yl)methyl chloroacetate (IS-4), were tested as internal standards for the quantification of patulin in apple juice by gas chromatography-mass spectrometry in the selected ion monitoring mode (GC-MS-SIM). The developed method combines an AOAC official extractive step and a GC-MS-SIM analysis. Using a chromatographic column containing trifluoropropylmethylpolysiloxane as the stationary phase and IS-1 as the internal standard, it was possible to perform an accurate and precise quantification of underivatizated patulin in apple juice at concentrations down to 6 microg/L. A detection limit of 1 microg/L was established.

  2. Facile Synthesis of a Hydroxyl-Functionalized Tröger’s Base Diamine: A New Building Block for High-Performance Polyimide Gas Separation Membranes

    KAUST Repository

    Ma, Xiaohua

    2017-12-04

    Two intrinsically microporous polyimides (PIM-PIs) were synthesized by the polycondensation reaction of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 3,3,3′,3′-tetramethylspirobisindane-6,7,6′,7′-tetracarboxylic dianhydride (SBI) with a newly designed o-hydroxyl-functionalized Tröger’s base diamine, 1,7-diamino-6H,12H-5,11-methanodibenzo[1,5]diazocine-2,8-diol (HTB). Both amorphous PIM-PIs were soluble in aprotic solvents and showed excellent thermal stability with onset decomposition temperature of ∼380 °C. SBI-HTB displayed a higher CO2 permeability (466 vs 67 barrer) than 6FDA-HTB but a significantly lower selectivity for CO2/CH4 (29 vs 73), H2/CH4 (29 vs 181), O2/N2 (4.6 vs 6.0), and N2/CH4 (1 vs 2.5). 6FDA-HTB displayed the highest gas-pair permselectivity values of all reported OH-functionalized PIM-PIs to date. The high permselectivity of 6FDA-HTB resulted primarily from exceptional diffusion selectivity due to strong size-sieving properties caused by hydrogen bonding between the proton of the hydroxyl group and the nitrogen atoms in the tertiary amine of the Tröger’s base (O–H···N).

  3. Synthesis of ZnMn2O4 Nanoparticles by a Microwave-Assisted Colloidal Method and their Evaluation as a Gas Sensor of Propane and Carbon Monoxide

    Directory of Open Access Journals (Sweden)

    Juan Pablo Morán-Lázaro

    2018-02-01

    Full Text Available Spinel-type ZnMn2O4 nanoparticles were synthesized via a simple and inexpensive microwave-assisted colloidal route. Structural studies by X-ray diffraction showed that a spinel crystal phase of ZnMn2O4 was obtained at a calcination temperature of 500 °C, which was confirmed by Raman and UV-vis characterizations. Spinel-type ZnMn2O4 nanoparticles with a size of 41 nm were identified by transmission electron microscopy. Pellet-type sensors were fabricated using ZnMn2O4 nanoparticles as sensing material. Sensing measurements were performed by exposing the sensor to different concentrations of propane or carbon monoxide at temperatures in the range from 100 to 300 °C. Measurements performed at an operating temperature of 300 °C revealed a good response to 500 ppm of propane and 300 ppm of carbon monoxide. Hence, ZnMn2O4 nanoparticles possess a promising potential in the gas sensors field.

  4. Hot Gas Cleanup Test Facility for gasification and pressurized combustion. Quarterly report, October--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the original Transport Reactor gas source and Hot Gas Cleanup Units: carbonizer/pressurized circulating fluidized bed gas source; hot gas cleanup units to mate to all gas streams; combustion gas turbine; and fuel cell and associated gas treatment. The major emphasis during this reporting period was continuing the detailed design of the facility and integrating the particulate control devices (PCDs) into structural and process designs. Substantial progress in underground construction activities was achieved during the quarter. Delivery and construction of coal handling and process structural steel began during the quarter. Delivery and construction of coal handling and process structural steel began during the quarter. MWK equipment at the grade level and the first tier are being set in the structure.

  5. Gas treating absorption theory and practice

    CERN Document Server

    Eimer, Dag

    2014-01-01

    Gas Treating: Absorption Theory and Practice provides an introduction to the treatment of natural gas, synthesis gas and flue gas, addressing why it is necessary and the challenges involved.  The book concentrates in particular on the absorption-desorption process and mass transfer coupled with chemical reaction. Following a general introduction to gas treatment, the chemistry of CO2, H2S and amine systems is described, and selected topics from physical chemistry with relevance to gas treating are presented. Thereafter the absorption process is discussed in detail, column hardware is explain

  6. Heterometallic molecular precursors for a lithium-iron oxide material: synthesis, solid state structure, solution and gas-phase behaviour, and thermal decomposition.

    Science.gov (United States)

    Han, Haixiang; Wei, Zheng; Barry, Matthew C; Filatov, Alexander S; Dikarev, Evgeny V

    2017-05-02

    Three heterometallic single-source precursors with a Li : Fe = 1 : 1 ratio for a LiFeO 2 oxide material are reported. Heterometallic compounds LiFeL 3 (L = tbaoac (1), ptac (2), and acac(3)) have been obtained on a large scale, in nearly quantitative yields by one-step reactions that employ readily available reagents. The heterometallic precursor LiFe(acac) 3 (3) with small, symmetric substituents on the ligand (acac = pentane-2,4-dionate), maintains a 1D polymeric structure in the solid state that limits its volatility and prevents solubility in non-coordinating solvents. The application of the unsymmetrical ligands, tbaoac (tert-butyl acetoacetate) and ptac (1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedionate), that exhibit different bridging properties at the two ends of the ligand, allowed us to change the connectivity pattern within the heterometallic assembly. The latter was demonstrated by structural characterization of heterometallic complexes LiFe(tbaoac) 3 (1) and LiFe(ptac) 3 (2) that consist of discrete heterocyclic tetranuclear molecules Li 2 Fe 2 L 6 . The compounds are highly volatile and exhibit a congruent sublimation character. DART mass spectrometric investigation revealed the presence of heterometallic molecules in the gas phase. The positive mode spectra are dominated by the presence of [M - L] + peaks (M = Li 2 Fe 2 L 6 ). In accord with their discrete molecular structure, complexes 1 and 2 are highly soluble in nearly all common solvents. In order to test the retention of the heterometallic structure in solution, the diamagnetic analog of 1, LiMg(tbaoac) 3 (4), has been isolated. Its tetranuclear molecular structure was found to be isomorphous to that of the iron counterpart. 1 H and 7 Li NMR spectroscopy unambiguously confirmed the presence of heterometallic molecules in solutions of non-coordinating solvents. The heterometallic precursor 1 was shown to exhibit clean thermal decomposition in air that results in phase-pure

  7. Organic synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, S.E.

    1991-01-01

    This paper reports on reactions of organoboranes. Organoboron routes to unsaturated hydrocarbons. Boronic ester homologation. Properties of organosilicon compounds. Alkene synthesis (Peterson olefination). Allylsilanes and acylsilanes.

  8. Natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, J W

    1967-08-01

    This report on the natural gas industry of Canada includes: composition and uses of natural gas, production statistics, exploration and development, reserve estimates, natural gas processing, transportation, and marketing. For the Canadian natural gas industry, 1966 was a year of moderate expansion in all phases, with a strong demand continuing for sulfur and liquid hydrocarbons produced as by-products of gas processing. Value of natural gas production increased to $199 million and ranked sixth in terms of value of mineral ouput in Canada. Currently, natural gas provides over 70% of Canada's energy requirements. Proved remaining marketable reserves are estimated to be in excess of a 29-yr supply.

  9. Gas Sensor

    KAUST Repository

    Luebke, Ryan

    2015-01-22

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  10. Gas Sensor

    KAUST Repository

    Luebke, Ryan; Eddaoudi, Mohamed; Omran, Hesham; Belmabkhout, Youssef; Shekhah, Osama; Salama, Khaled N.

    2015-01-01

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  11. Gas manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Fell, J W

    1915-05-03

    Retorts for the distillation of shale or coal for the production of oil or illuminating-gas are heated by gas from a generator or a gas-holder, and a portion of the gas from the flue leading to the heating-flues is forced by a steam jet through a by-pass and is injected into the bottom of the retorts. If the gas to be admitted to the retort is cold, it is first heated.

  12. Natural Gas

    OpenAIRE

    Bakar, Wan Azelee Wan Abu; Ali, Rusmidah

    2010-01-01

    Natural gas fuel is a green fuel and becoming very demanding because it is environmental safe and clean. Furthermore, this fuel emits lower levels of potentially harmful by-products into the atmosphere. Most of the explored crude natural gas is of sour gas and yet, very viable and cost effective technology is still need to be developed. Above all, methanation technology is considered a future potential treatment method for converting the sour natural gas to sweet natural gas.

  13. Gas mission; Mission gaz

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This preliminary report analyses the desirable evolutions of gas transport tariffing and examines some questions relative to the opening of competition on the French gas market. The report is made of two documents: a synthesis of the previous report with some recommendations about the tariffing of gas transport, about the modalities of network access to third parties, and about the dissociation between transport and trade book-keeping activities. The second document is the progress report about the opening of the French gas market. The first part presents the European problem of competition in the gas supply and its consequences on the opening and operation of the French gas market. The second part presents some partial syntheses about each topic of the mission letter of the Ministry of Economics, Finances and Industry: future evolution of network access tariffs, critical analysis of contractual documents for gas transport and delivery, examination of auxiliary services linked with the access to the network (modulation, balancing, conversion), consideration about the processing of network congestions and denied accesses, analysis of the metering dissociation between the integrated activities of gas operators. Some documents are attached in appendixes: the mission letter from July 9, 2001, the detailed analysis of the new temporary tariffs of GdF and CFM, the offer of methane terminals access to third parties, the compatibility of a nodal tariffing with the presence of three transport operators (GdF, CFM and GSO), the contract-type for GdF supply, and the contract-type for GdF connection. (J.S.)

  14. Increase of Bio-Gas Power Potential

    OpenAIRE

    V. A. Sednin; О. F. Kraetskaya; I. N. Prokoрenia

    2012-01-01

    The paper presents a review of industrial technologies for obtaining gas-synthesis which is applicable for bio-gas enrichment process. Comparative characteristics are given in the paper. The paper thoroughly considers a technology of dry methane conversion as the most expedient variant recommended for the application in this case. The bio-gas enrichment carried out during its production expands possibilities and efficiency of its application.

  15. Increase of Bio-Gas Power Potential

    Directory of Open Access Journals (Sweden)

    V. A. Sednin

    2012-01-01

    Full Text Available The paper presents a review of industrial technologies for obtaining gas-synthesis which is applicable for bio-gas enrichment process. Comparative characteristics are given in the paper. The paper thoroughly considers a technology of dry methane conversion as the most expedient variant recommended for the application in this case. The bio-gas enrichment carried out during its production expands possibilities and efficiency of its application.

  16. Organic synthesis

    International Nuclear Information System (INIS)

    Lallemand, J.Y.; Fetizon, M.

    1988-01-01

    The 1988 progress report of the Organic Synthesis Chemistry laboratory (Polytechnic School, France), is presented. The laboratory activities are centered on the chemistry of natural products, which have a biological activity and on the development of new reactions, useful in the organic synthesis. The research works involve the following domains: the natural products chemistry which are applied in pharmacology, the plants and insects chemistry, the organic synthesis, the radical chemistry new reactions and the bio-organic physicochemistry. The published papers, the congress communications and the thesis are listed [fr

  17. Biogas as a fuel for solid oxide fuel cells and synthesis gas production: effects of ceria-doping and hydrogen sulfide on the performance of nickel-based anode materials.

    Science.gov (United States)

    Laycock, Christian J; Staniforth, John Z; Ormerod, R Mark

    2011-05-28

    Numerous investigations have been carried out into the conversion of biogas into synthesis gas (a mixture of H(2) + CO) over Ni/YSZ anode cermet catalysts. Biogas is a variable mixture of gases consisting predominantly of methane and carbon dioxide (usually in a 2 : 1 ratio, but variable with source), with other constituents including sulfur-containing gases such as hydrogen sulfide, which can cause sulfur poisoning of nickel catalysts. The effect of temperature on carbon deposition and sulfur poisoning of 90 : 10 mol% Ni/YSZ under biogas conversion conditions has been investigated by carrying out a series of catalytic reactions of methane-rich (2 : 1) CH(4)/CO(2) mixtures in the absence and presence of H(2)S over the temperature range 750-1000 °C. The effect of ceria-doping on carbon dioxide reforming, carbon deposition and sulfur tolerance has also been investigated by carrying out a similar series of reactions over ceria-doped Ni/YSZ. Ceria was doped at 5 mol% of the nickel content to give an anode catalyst composition of 85.5 : 4.5 : 10 mol% Ni/CeO(2)/YSZ. Reactions were followed using quadrupolar mass spectrometry (QMS) and the amount of carbon deposition was analysed by subjecting the reacted catalyst samples to a post-reaction temperature programmed oxidation (TPO). On undoped Ni/YSZ, carbon deposition occurred predominantly through thermal decomposition of methane. Ceria-doping significantly suppressed methane decomposition and at high temperatures simultaneously promoted the reverse Boudouard reaction, significantly lowering carbon deposition. Sulfur poisoning of Ni/YSZ occurred in two phases, the first of which caused the most activity loss and was accelerated on increasing the reaction temperature, while the second phase had greater stability and became more favourable with increasing reaction temperature. Adding H(2)S significantly inhibited methane decomposition, resulting in much less carbon deposition. Ceria-doping significantly increased the sulfur

  18. Rh promoted La0.75Sr0.25(Fe0.8Co0.2)1−xGaxO3-δ perovskite catalysts: Characterization and catalytic performance for methane partial oxidation to synthesis gas

    International Nuclear Information System (INIS)

    Palcheva, R.; Olsbye, U.; Palcut, M.; Rauwel, P.; Tyuliev, G.; Velinov, N.; Fjellvåg, H.H.

    2015-01-01

    Graphical abstract: - Highlights: • Perovskites type-oxide La 0.75 Sr 0.25 (Fe 0.8 Co 0.2 ) 1−x Ga x O 3-δ (x = 0.1, 0.25, 0.4) prepared by the sol–gel citrate method. • Bulk and surface analysis to determine catalysts composition evolution. • Anaerobic catalytic partial oxidation of methane to syngas at 600 °C in a pulse apparatus over Rh promoted perovskites. • The catalysts showed high stability and selectivity. - Abstract: Synthesis gas production via selective oxidation of methane at 600 °C in a pulse reaction over La 0.75 Sr 0.25 (Fe 0.8 Co 0.2 ) 1−x Ga x O 3-δ (x = 0.1, 0.25, 0.4) perovskite-supported rhodium catalysts, was investigated. The perovskite oxides were prepared by sol–gel citrate method and characterized by X-ray Diffraction (XRD), Moessbauer Spectroscopy (MS), Temperature Programmed Reduction (TPR-H 2 ), X-ray Photoelectron Spectroscopy (XPS) and High Resolution Transmission Electron Microscopy (HRTEM). According to XRD analysis, the synthesized samples were a single perovskite phase. The perovskite structure of Ga substituted samples remained stable after TPR-H 2 , as confirmed by XRD. Data of MS identified Fe 3+ ions in two distinctive coordination environments, and Fe 4+ ions. The Rh 2 O 3 thin overlayer was detected by the HRTEM for the Rh impregnated perovskite oxides. During the interaction of methane with oxidized perovskite-supported Rh (0.5 wt.%) catalysts, besides CO, H 2 , and surface carbon, CO 2 and H 2 O were formed. The Rh perovskite catalyst with x = 0.25 gallium exhibits the highest catalytic activity of 83% at 600 °C. The CO selectivity was affected by the reducibility of La 0.75 Sr 0.25 (Fe 0.8 Co 0.2 ) 1−x Ga x O 3-δ perovskite materials.

  19. Process for producing alcohols from synthesis gas

    International Nuclear Information System (INIS)

    Stevens, R.R.

    1988-01-01

    A process is described for making alcohols comprising contacting a mixture of hydrogen and carbon monoxide with a catalyst comprising: (1) as a first component, at least one element selected from the group consisting of molybdenum and tungsten in free or combined form; (2) as a second component, at least one element selected from the group consisting of cobalt and nickel in free or combined form; (3) as a third component, a promoter comprising an alkali or alkaline earth element in free or combined form; the catalyst excluding rhodium and ruthenium and containing less than two (2) weight percent copper; at a pressure of at least about 500 psig and at conditions sufficient to form an alcohol fraction boiling in the range of motor gasoline in at least 20 percent CO/sub 2/ free carbon selectivity, the alcohol fraction containing a C/sub 1/ to C/sub 2-5/ alcohol weight ratio of less than about 1:1

  20. Synthesis, characterization and gas sensing performance of ...

    Indian Academy of Sciences (India)

    death of an animal [11]. Some of the researchers have reported some metal oxide materials [12–20], polyaniline. [21], Nafion [22] and polypyrrole [23] thin ... The thermal behavior of the cancri- nite was examined within the temperature range of room tem- perature to 853 K. The MAS NMR of 23Na, and 29Si nuclei analysis ...

  1. Synthesis, characterization and gas sensing property

    Indian Academy of Sciences (India)

    ... studies showed the Ca/P ratio of 1.63 for the HAp sample prepared by chemical process. ... School of Physical Sciences, Swami Ramanand Teerth Marathwada ... Manuscript received: 16 November 2004; Manuscript revised: 9 August 2005 ...

  2. Tunable synthesis of copper nanotubes

    International Nuclear Information System (INIS)

    Kaniukov, E; Yakimchuk, D; Kozlovsky, A; Shlimas, D; Zdorovets, M; Kadyrzhanov, K

    2016-01-01

    Simple method of tunable synthesis of copper nanotubes based on template synthesis was developed. A comprehensive study of the structural, morphological and electrical characteristics of the obtained nanostructures was carried out. Characterization of structural features was made by methods of scanning electron microscopy, energy dispersive spectroscopy and X-ray diffractometry analysis. Evaluation of wall thickness is made by methods of gas permeability. Electrical conductivity of nanotubes was define in the study of their current-voltage characteristics. The possibility to control of copper nanotubes physical properties by variation of the deposition parameters was shown. (paper)

  3. Metabolic regulation in Streptomyces parvulus during actinomycin D synthesis, studied with 13C- and 15N-labeled precursors by 13C and 15N nuclear magnetic resonance spectroscopy and by gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Inbar, L.; Lapidot, A.

    1988-01-01

    Recent studies have suggested that the onset of synthesis of actinomycin D in Streptomyces is due to a release from L-glutamate catabolic repression. In the present investigation we showed that S. parvulus has the capacity to maintain high levels of intracellular glutamate during the synthesis of actinomycin D. The results seem contradictory, since actinomycin D synthesis cannot start before a release from L-glutamate catabolic repression, but a relatively high intracellular pool of glutamate is needed for the synthesis of actinomycin D. Utilizing different labeled precursors, D-[U- 13 C]fructose and 13 C- and 15 N-labeled L-glutamate, and nuclear magnetic resonance techniques, we showed that carbon atoms of an intracellular glutamate pool of S. parvulus were not derived biosynthetically from the culture medium glutamte source but rather from D-fructose catabolism. A new intracellular pyrimidine derivative whose nitrogen and carbon skeletons were derived from exogenous L-glutamate was obtained as the main glutamate metabolite. Another new pyrimidine derivative that had a significantly reduced intracellular mobility and that was derived from D-fructose catabolism was identified in the cell extracts of S. parvulus during actinomycin D synthesis. These pyrimidine derivatives may serve as a nitrogen store for actinomycin D synthesis. In the present study, the N-trimethyl group of a choline derivative was observed by 13 C nuclear magnetic resonance spectroscopy in growing S. parvulus cells. The choline group, as well as the N-methyl groups of sarcosine, N-methyl-valine, and the methyl groups of an actinomycin D chromophore, arose from D-fructose catabolism. The 13 C enrichments found in the peptide moieties of actinomycin D were in accordance with a mechanism of actinomycin D synthesis from L-glutamate and D-fructose

  4. GAS BEARING

    Science.gov (United States)

    Skarstrom, C.W.

    1960-09-01

    A gas lubricated bearing for a rotating shaft is described. The assembly comprises a stationary collar having an annular member resiliently supported thereon. The collar and annular member are provided with cooperating gas passages arranged for admission of pressurized gas which supports and lubricates a bearing block fixed to the rotatable shaft. The resilient means for the annular member support the latter against movement away from the bearing block when the assembly is in operation.

  5. Requirements for gas quality and gas appliances

    NARCIS (Netherlands)

    Levinsky, Howard; Gersen, Sander; Kiewiet, Bert

    2015-01-01

    Introduction The gas transmission network in the Netherlands transports two different qualities of gas, low-calorific gas known as G-gas or L-gas and, high calorific gas (H-gas). These two gas qualities are transported in separate networks, and are connected by means of five blending and conversion

  6. Gas magnetometer

    Science.gov (United States)

    Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert

    2016-05-03

    Measurement of a precessional rate of a gas, such as an alkali gas, in a magnetic field is made by promoting a non-uniform precession of the gas in which substantially no net magnetic field affects the gas during a majority of the precession cycle. This allows sensitive gases that would be subject to spin-exchange collision de-phasing to be effectively used for extremely sensitive measurements in the presence of an environmental magnetic field such as the Earth's magnetic field.

  7. Gas separating

    Science.gov (United States)

    Gollan, A.

    1988-03-29

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  8. Report for fiscal 1995 by Coal Gasification Committee; 1995 nendo sekitan gas ka iinkai hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This is a summary primarily of the distributed material. As of December 14, 1995, the 200t/d pilot plant for power generation by entrained bed coal gasification records a total coal gasification operation time of 4,485 hours with an accumulated amount of power generation of 9,227MWh. A large combustor is tested, and it is found that combustion is stable under a 1/4 load with low NOx emissions. The combustor is sufficiently cooled with a small supply of air. Coal ash and coal, supplied in a constant state for an improved heat recovery efficiency in the development of hydrogen-from-coal technology, are heated to a temperature near their melting points. They are then allowed to impinge at a heat transfer plane simulating a gasifier heat recovery section, and a study is made of the mechanism of ash adhesion, molten or semi-molten, to the heat recovery section. The reduction of the heat transfer coefficient due to added grains is 30-50%, and the reduction is small when the heat transfer pipe surface velocity is high or when the carbon concentration in the grains is high. In another effort, utilization of coal-derived gas as town gas is studied. As for yields as indicated by the Curie gas pyrolyzer, the gas yield increases and liquid yield decreases when the reaction temperature is high. Using a small test unit, it is found that a rise in the hydrogen partial pressure increases the production of both gas and liquid. (NEDO)

  9. Manure gas

    Energy Technology Data Exchange (ETDEWEB)

    Carre, I

    1947-05-01

    A short description of the process is given, with gas yields from various feedstocks, and the composition of the gas. Short descriptions of several batch digester designs are given: Algerian, Salubra, Betur, Baudot-Hardoll and Ofta, and Somagaz. The utilization and the economics of the process are discussed. Two diagrams of Ducellier and Isman designs are included.

  10. Landfill gas

    International Nuclear Information System (INIS)

    Hartnell, Gaynor

    2000-01-01

    Following the UK Government's initiative for stimulating renewable energy through the Non-Fossil Fuel Obligation (NFFO), the UK landfill gas industry has more than trebled in size in just 4 years. As a result, UK companies are now in a strong position to offer their skills and services overseas. Ireland, Greece and Spain also resort heavily to disposal to landfill. Particularly rapid growth of the landfill gas market is expected in the OECD-Pacific and NAFTA areas. The article explains that landfill gas is a methane-rich mixture produced by anaerobic decomposition of organic wastes in landfills: under optimum conditions, up to 500 cubic meters of gas can be obtained from 1 tonne of biodegradable waste. Data on the number and capacity of sites in the UK are given. The Landfill Gas Association runs courses to counteract the skills shortage in the UK, and tailored courses for overseas visitors are planned

  11. On the deactivation of cobalt-based Fischer-Tropsch synthesis catalysts

    NARCIS (Netherlands)

    Moodley, D.J.

    2008-01-01

    The catalytic conversion of synthesis gas, derived from natural gas, into liquid hydrocarbon fuel via the Fischer–Tropsch synthesis (FTS), is currently receiving much attention due to the demand for environmentally friendly liquid fuel and the rising costs of crude oil. From an industrial

  12. Synthesis and characterization of a microporous 6FDA-polyimide made from a novel carbocyclic pseudo Tröger's base diamine: Effect of bicyclic bridge on gas transport properties

    KAUST Repository

    Abdulhamid, Mahmoud A.; Ma, Xiaohua; Miao, Xiaohe; Pinnau, Ingo

    2017-01-01

    ,11-methanodibenzo[a,e][8]annulene (iCTBDA), were designed for the synthesis of microporous 6FDA-based polyimides (6FDA-CTBDA and 6FDA-iCTBDA). Both polyimides were soluble, exhibited excellent thermal stability of ∼490 °C, and had high surface areas of 587 m2 g−1 (6

  13. Coal-based synthetic natural gas (SNG): A solution to China’s energy security and CO2 reduction?

    International Nuclear Information System (INIS)

    Ding, Yanjun; Han, Weijian; Chai, Qinhu; Yang, Shuhong; Shen, Wei

    2013-01-01

    Considering natural gas (NG) to be the most promising low-carbon option for the energy industry, large state owned companies in China have established numerous coal-based synthetic natural gas (SNG) projects. The objective of this paper is to use a system approach to evaluate coal-derived SNG in terms of life-cycle energy efficiency and CO 2 emissions. This project examined main applications of the SNG and developed a model that can be used for evaluating energy efficiency and CO 2 emissions of various fuel pathway systems. The model development started with the GREET model, and added the SNG module and an end-use equipment module. The database was constructed with Chinese data. The analyses show when the SNG are used for cooking, power generation, steam production for heating and industry, life-cycle energies are 20–108% higher than all competitive pathways, with a similar rate of increase in life-cycle CO 2 emissions. When a compressed natural gas (CNG) car uses the SNG, life-cycle CO 2 emission will increase by 150–190% compared to the baseline gasoline car and by 140–210% compared to an electric car powered by electricity from coal-fired power plants. The life-cycle CO 2 emission of SNG-powered city bus will be 220–270% higher than that of traditional diesel city bus. The gap between SNG-powered buses and new hybrid diesel buses will be even larger—life-cycle CO 2 emission of the former being around 4 times of that of the latter. It is concluded that the SNG will not accomplish the tasks of both energy conservation and CO 2 reduction. - Highlights: ► We evaluated life-cycle energy efficiency and CO 2 emissions of coal-derived SNG. ► We used GREET model and added a coal-based SNG and an end-use modules. ► The database was constructed with Chinese domestic data. ► Life-cycle energies and CO 2 emissions of coal-based SNG are 20–100% higher. ► Coal-based SNG is not a solution to both energy conservation and CO 2 reduction

  14. Treatment of Gas

    Science.gov (United States)

    ... Funding IFFGD Symposium reports Industry Council Contact Us Treatment of Gas You are here: Home Symptoms & Causes Intestinal Gas ... Controlling Intestinal Gas Foods That May Cause Gas Treatment of Gas Tips on Controlling Gas Adapted from IFFGD Publication # ...

  15. Asian gas

    International Nuclear Information System (INIS)

    Masuda, T.

    1990-01-01

    This paper reports on natural gas which now appears ready to take a leading role on the world energy stage. Demand for natural gas, and specifically LNG, will be strong throughout the world, particularly in Asia. Indonesia and Malaysia will become much more dependent on natural gas in the Asian market. In Thailand, where remarkable economic growth has been fueled by imported oil and domestically produced natural gas, LNG may soon have to be imported from neighboring countries. The author sees Thailand's imports of natural gas increasing from 1.5 to 4.5 million tons annually. Similarly, Korea's imports of LNG will rise from 2 to 8 million tons between 1987 and 2000. In Japan, energy demand is expected to increase at an even faster rate in the 1990s. Given the opposition to nuclear power generation and growing concern about the greenhouse effect, it is likely that LNG will satisfy a major portion of Japan's increasing demand for energy. Japanese gas companies are studying the possibility of establishing a national pipeline network to move gas beyond metropolitan areas

  16. Energy Efficient Hybrid Gas Separation with Ionic Liquids

    DEFF Research Database (Denmark)

    Liu, Xinyan; Liang, Xiaodong; Gani, Rafiqul

    2017-01-01

    Shale gas, like natural gas, contains H2, CO2, CH4 and that light hydrocarbon gases needs processing to separate the gases for conversion to higher value products. Currently, distillation based separation is employed, which is energy intensive. Hybrid gas separation processes, combining absorption...... systems is established for process design-analysis. A strategy for hybrid gas separation process synthesis where distillation and IL-based absorption are employed for energy efficient gas processing is developed and its application is highlighted for a model shale gas processing case study....

  17. Axial and Radial Gas Holdup in Bubble Column Reactor

    International Nuclear Information System (INIS)

    Wagh, Sameer M.; Ansari, Mohashin E Alan; Kene, Pragati T.

    2014-01-01

    Bubble column reactors are considered the reactor of choice for numerous applications including oxidation, hydrogenation, waste water treatment, and Fischer-Tropsch (FT) synthesis. They are widely used in a variety of industrial applications for carrying out gas-liquid and gas-liquid-solid reactions. In this paper, the computational fluid dynamics (CFD) model is used for predicting the gas holdup and its distribution along radial and axial direction are presented. Gas holdup increases linearly with increase in gas velocity. Gas bubbles tends to concentrate more towards the center of the column and follows a wavy path

  18. Gas dusulfurization

    International Nuclear Information System (INIS)

    Powell, B.E.; Bakhshi, V.S.; Randolph, D.A.

    1984-01-01

    A process for adsorbing sulfur dioxide from a gas comprising contacting a gas containing SO 2 , such as a flue gas, with about stoichiometric amounts of a specially prepared calcium oxide so that substantially all of the sulfur dioxide content is reacted throughout the calcium oxide particle to form a calcium sulfate reaction product. The useful calcium oxide particles comprise a highly voided skeletal structure of very large surface area and large pore volume with numerous macro pores. Such particles are obtained by flash calcining sand-size grains of calcium carbonate, such as aragonite, calcite or dolomite

  19. Gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Farahan, E.; Eudaly, J.P.

    1978-10-01

    This evaluation provides performance and cost data for commercially available simple- and regenerative-cycle gas turbines. Intercooled, reheat, and compound cycles are discussed from theoretical basis only, because actual units are not currently available, except on a special-order basis. Performance characteristics investigated include unit efficiency at full-load and off-design conditions, and at rated capacity. Costs are tabulated for both simple- and regenerative-cycle gas turbines. The output capacity of the gas turbines investigated ranges from 80 to 134,000 hp for simple units and from 12,000 to 50,000 hp for regenerative units.

  20. Energy Conservation Alternatives Study (ECAS): Conceptual Design and Implementation Assessment of a Utility Steam Plant with Conventional Furnace and Wet Lime Stack Gas Scrubbers

    Science.gov (United States)

    Brown, Dale H.

    1976-01-01

    A study was performed to estimate the technical/economic characteristics of a steam power plant (3500 pounds per square inch gauge, 1000 degrees Fahrenheit / 1000 degrees Fahrenheit) with a coal-burning radiant furnace and a wet lime stack gas scrubber to control sulfur emissions. Particulate emissions were controlled by an electrostatic precipitator operating at 300 degrees Fahrenheit. The stack gas from the scrubber was reheated from 125 degrees Fahrenheit to 250 degrees Fahrenheit as a base case, and from 125 degrees Fahrenheit to 175 degrees Fahrenheit as an alternate case. The study was performed on a basis consistent with the General Electric ECAS Phase II evaluation of advanced energy conversion systems for electric utility baseload applications using coal or coal-derived fuels. A conceptual design of the power plant was developed, including the on-site calcination of limestone to lime and the provision of sludge ponds to store the products of flue gas scrubbing. From this design, estimates were derived for power plant efficiency, capital cost, environmental intrusion characteristics, natural resource requirements, and cost of electricity at an assumed capacity factor of 65 percent. An implementation assessment was performed where factors affecting applicability of the conceptual design power plant in electric utility generation systems were appraised. At 250 degrees Fahrenheit and 175 degrees Fahrenheit stack gas temperatures respectively, the plants showed a cost of electricity of 39.8 and 37.0 mills per kilowatt-hours and overall plant efficiencies of 32 percent and 34 percent.

  1. Volcanic Gas

    Science.gov (United States)

    ... offensive odor. It is sometimes referred to as sewer gas. Interestingly, the human nose is more sensitive ... the atmosphere where they can potentially cause acid rain. In an ash -producing eruption, ash particles are ...

  2. Gas - flatulence

    Science.gov (United States)

    ... Gas and other symptoms such as stomach pain, rectal pain, heartburn, nausea, vomiting, diarrhea, constipation, fever, or ... Copyright 1997-2018, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing ...

  3. Gas sensor

    International Nuclear Information System (INIS)

    Dorogan, V.; Korotchenkov, Gh.; Vieru, T.; Prodan, I.

    2003-01-01

    The invention relates to the gas sensors on base of metal-oxide films (SnO, InO), which may be used for enviromental control, in the fireextinguishing systema etc. The gas includes an insulating substrate, an active layer, a resistive layer with ohmic contacts. The resistive layer has two or more regions with dofferent resistances , and on the active layer are two or more pairs of ohmic contacts

  4. Tomorrow, gas

    International Nuclear Information System (INIS)

    Icart, Laura; Jean, Pascale; Georget, Cyrille; Schmill, Rafael

    2017-01-01

    This document contains 12 articles notably addressing the importance of natural gas production and supplies in Europe. The themes of the articles are: the advantages of natural gas in the context of energy and environmental policies, energy diversification, energy supply in the local territories, etc.; the position of GrDF, one of the main French natural gas supplier; LPG (butane, propane), a solution which popularity grows in remote areas; the Gaya project (production of renewable gas from dry biomass); a panorama of gas supply routes in Europe; the situation of gas in Europe's energy supply and consumption; the promotion of LNG fuel for maritime and fluvial ships; why the small scale LNG could be the next revolution; presentation of the new 'Honfleur' ferry (using LNG fuel) that will cross the English Channel by 2019; carbon market and the role of ETS for the energy policy in Europe facing the climatic change challenge; presentation of the French 'Climate Plan' that aims to engage France into a carbon neutrality by 2050; presentation of the French policy against air pollution; economic growth, energy, climate: how to square this circle?

  5. Synthesis of tritium-labeled fosfomycin

    International Nuclear Information System (INIS)

    Mertel, H.E.; Meriwether, H.T.

    1982-01-01

    Tritium gas was used as a labeling agent for the preparation of [1,2- 3 H]fosfomycin. Introduction of tritium into a precursor, the synthesis including resolution of the intermediate racemic 1,2-epoxypropylphosphonic acid, and preparation of both amine and calcium salts of the labeled antibiotic are described. (author)

  6. Enabling lean design of biomethane gas distribution grids

    NARCIS (Netherlands)

    Weidenaar, Teade; Jauregui Becker, Juan Manuel; Hoekstra, Sipke

    2015-01-01

    The Dutch gas distribution infrastructure faces several significant changes in the near future. One of the major changes is the production and injection of biomethane into the gas distribution grid. This article introduces a Design Synthesis Tool (DST) that automatically generates biomethane supply

  7. Substituted polynorbornenes as promising materials for gas separation membranes

    International Nuclear Information System (INIS)

    Finkelshtein, Evgenii Sh; Bermeshev, Maksim V; Gringolts, Mariya L; Starannikova, L E; Yampolskii, Yu P

    2011-01-01

    Published results concerning the synthesis and study of the transport characteristics of polynorbornenes are considered and analyzed. Conclusions are drawn regarding the effect of the backbone rigidity and the nature of side groups on the gas permeability level. The prospects of using addition organosilicon polynorbornenes as gas separating membrane materials are discussed.

  8. Fabrication, characterization and gas sensing properties of gold ...

    Indian Academy of Sciences (India)

    Calixarenes are a group of materials that are widely used for gas sensing studies because of their simple synthesis, conformational flexibility, binding group tunability, variability in their cavity sizes and improved selectivity to different gas molecules. In recent years it has been shown that incorporation of gold nanoparticles ...

  9. Selection of an industrial natural-gas-fired advanced turbine system - Task 3A

    Energy Technology Data Exchange (ETDEWEB)

    Holloway, G.M.

    1997-05-01

    TASK OBJECTIVES: Identify a gas-fueled turbine and steam system which will meet the program goals for efficiency - and emissions. TECHNICAL GOALS AND REQUIREMENTS: Goals for the Advanced Turbine System Program (ATS) where outlined in the statement of work for five basic categories: Cycle Efficiency - System heat rate to have a 15% improvement over 1991 vintage systems being offered to the market. Environmental No post-combustion devices while meeting the following parameter targets: (1) Nitrous Oxide (NO{sub x}) emissions to equal 8 parts per million dry (ppmd) with 15% oxygen. (2) Carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions to equal 20 parts per million(ppmd) each. Cost of electricity to be 10 percent less when compared to similar 1991 systems. Fuel Flexibility Have to ability to burn coal or coal derived fuels without extensive redesign. Reliability, Availability, Maintainability Reliability, availability and maintainability must be comparable to modern advanced power generation systems. For all cycle and system studies, analyses were done for the following engine system ambient conditions: Temperature - 59F; Altitude - Sea Level; Humidity - 60%. For the 1991 reference system, GE Aircraft Engines used its LM6OOO engine product offering for comparison of the Industrial System parameters developed under this program.

  10. Gas war

    International Nuclear Information System (INIS)

    Shiry, J.

    1992-01-01

    The sale of natural gas to California is one of the most complex and contested trade disputes between the USA and Canada. The background and the issues involved are discussed. An oversupply of Canadian gas, combined with USA subsidies for producing coalbed methane and a general oversupply of gas in the USA, have made spot gas prices decline to unexpectedly low levels. California regulators have responded to this situation by trying to secure the lowest possible prices for consumers, thereby causing them to abandon long-standing trade policies with Canada. The main agent of this change is the California Public Utilities Commission (CPUC), whose actions have reduced the value of Canadian exports and Alberta government revenues by at least $250 million annually. CPUC supported buying from a supply pool (Alberta ampersand Southern Gas) since it provided monopoly purchasing power, and CPUC's policy against pipeline expansion produced the limited access to California that the CPUC now cites as evidence of a producer cartel. CPUC has interfered in contracts with Canadian producers in its pipeline access policies, its capacity brokering decision of 1991, and its reasonableness test for past sales. In its haste to force its own view of market results onto existing contractual relationships, the CPUC is not allowing open negotiations to reshape the relationship, and CPUC actions may be generating countermeasures by Alberta that are inappropriate under deregulation. 3 figs

  11. Gas attack

    Energy Technology Data Exchange (ETDEWEB)

    North, D.

    1977-08-01

    Consumersfirst Ltd. is reacting to deregulation with a massive advertising campaign. The gas utility is owned by Consumers Gas Energy Inc., and is struggling to hold onto its 35 per cent share of Ontario`s two million residential natural gas buyers. An industry analyst pointed out that deregulation could mean that Consumers` Gas has much to lose: customers, market share, control of the assets and control of the process. The Ontario Energy Board (OEB) however, had specified that Consumersfirst is not to proceed with paperwork to sign up new customers until the OEB issues a draft code-of-conduct that would prevent cross-subsidizing between regulated franchise holders. This has now been done, and several heavyweights such as Calgary-based Suncor Energy Inc., Union Gas of Chatham, Ontario, and the US-based Enron Corp. of Houston, have started campaigns to sign up potential consumers. It is predicted that brand loyalty will be a factor, but in the end, like long distance telephone rates, it will all come down to pricing, and a winning formula is not easy to find.

  12. Nonsymmetric gas transfer phenomena in nanoporous media

    International Nuclear Information System (INIS)

    Kurchatov, I.M.

    2011-01-01

    The regularities of nonsymmetric gas (nitrogen, helium, hydrogen, carbon dioxide) transfer in nanoporous materials are investigated. The effects of anisotropy and hysteresis of permeability in nanoporous media with pore gradient and porosity in objects of various nature are found out. The following objects are studied: polyethylene terephthalate track membranes with asymmetric pore form, commercial polyvinyl trimethylsilane gas-separation membranes with continuous distribution of pores over the membrane thickness and porous composite membranes (born nitride, silicon carbide, aluminium oxide) prepared by self-propagating high-temperature synthesis with abrupt change of pore dimensions over the thickness. The possible mechanisms of nonsymmetric gas transfer effects are under consideration [ru

  13. First Fifty Years of Chemoresistive Gas Sensors

    Directory of Open Access Journals (Sweden)

    Giovanni Neri

    2015-01-01

    Full Text Available The first fifty years of chemoresistive sensors for gas detection are here reviewed, focusing on the main scientific and technological innovations that have occurred in the field over the course of these years. A look at advances made in fundamental and applied research and leading to the development of actual high performance chemoresistive devices is presented. The approaches devoted to the synthesis of novel semiconducting materials with unprecedented nanostructure and gas-sensing properties have been also presented. Perspectives on new technologies and future applications of chemoresistive gas sensors have also been highlighted.

  14. Synthesis of ammonia using sodium melt.

    Science.gov (United States)

    Kawamura, Fumio; Taniguchi, Takashi

    2017-09-14

    Research into inexpensive ammonia synthesis has increased recently because ammonia can be used as a hydrogen carrier or as a next generation fuel which does not emit CO 2 . Furthermore, improving the efficiency of ammonia synthesis is necessary, because current synthesis methods emit significant amounts of CO 2 . To achieve these goals, catalysts that can effectively reduce the synthesis temperature and pressure, relative to those required in the Haber-Bosch process, are required. Although several catalysts and novel ammonia synthesis methods have been developed previously, expensive materials or low conversion efficiency have prevented the displacement of the Haber-Bosch process. Herein, we present novel ammonia synthesis route using a Na-melt as a catalyst. Using this route, ammonia can be synthesized using a simple process in which H 2 -N 2 mixed gas passes through the Na-melt at 500-590 °C under atmospheric pressure. Nitrogen molecules dissociated by reaction with sodium then react with hydrogen, resulting in the formation of ammonia. Because of the high catalytic efficiency and low-cost of this molten-Na catalyst, it provides new opportunities for the inexpensive synthesis of ammonia and the utilization of ammonia as an energy carrier and next generation fuel.

  15. IGNITION IMPROVEMENT OF LEAN NATURAL GAS MIXTURES

    Energy Technology Data Exchange (ETDEWEB)

    Jason M. Keith

    2005-02-01

    This report describes work performed during a thirty month project which involves the production of dimethyl ether (DME) on-site for use as an ignition-improving additive in a compression-ignition natural gas engine. A single cylinder spark ignition engine was converted to compression ignition operation. The engine was then fully instrumented with a cylinder pressure transducer, crank shaft position sensor, airflow meter, natural gas mass flow sensor, and an exhaust temperature sensor. Finally, the engine was interfaced with a control system for pilot injection of DME. The engine testing is currently in progress. In addition, a one-pass process to form DME from natural gas was simulated with chemical processing software. Natural gas is reformed to synthesis gas (a mixture of hydrogen and carbon monoxide), converted into methanol, and finally to DME in three steps. Of additional benefit to the internal combustion engine, the offgas from the pilot process can be mixed with the main natural gas charge and is expected to improve engine performance. Furthermore, a one-pass pilot facility was constructed to produce 3.7 liters/hour (0.98 gallons/hour) DME from methanol in order to characterize the effluent DME solution and determine suitability for engine use. Successful production of DME led to an economic estimate of completing a full natural gas-to-DME pilot process. Additional experimental work in constructing a synthesis gas to methanol reactor is in progress. The overall recommendation from this work is that natural gas to DME is not a suitable pathway to improved natural gas engine performance. The major reasons are difficulties in handling DME for pilot injection and the large capital costs associated with DME production from natural gas.

  16. Development of biomass gasification systems for gas turbine power generation

    International Nuclear Information System (INIS)

    Larson, E.D.; Svenningsson, P.

    1991-01-01

    Gas turbines are of interest for biomass applications because, unlike steam turbines, they have relatively high efficiencies and low unit capital costs in the small sizes appropriate for biomass installations. Gasification is a simple and efficient way to make biomass usable in gas turbines. The authors evaluate here the technical requirements for gas turbine power generation with biomass gas and the status of pressurized biomass gasification and hot gas cleanup systems. They also discuss the economics of gasifier-gas turbine cycles and make some comparisons with competing technologies. Their analysis indicates that biomass gasifiers fueling advanced gas turbines are promising for cost-competitive cogeneration and central station power generation. Gasifier-gas turbine systems are not available commercially, but could probably be developed in 3 to 5 years. Extensive past work related to coal gasification and pressurized combustion of solid fuels for gas turbines would be relevant in this effort, as would work on pressurized biomass gasification for methanol synthesis

  17. Fire Synthesis

    Indian Academy of Sciences (India)

    Such unique prQper- ties coupled with its low cost makes alumina the most commonly used ... cal processing, oil and gas processing, refractories, preparation of synthetic ... know some of the latest developments in the combustion field. Combustion .... there is a control over stoichiometry, homogeneity and purity. It is easy to ...

  18. Gas hydrates

    Digital Repository Service at National Institute of Oceanography (India)

    Ramprasad, T.

    , not all of them are white like snow. Some hydrates from the deep Gulf of Mexico are richly colored in shades of yellow, orange, or even red. The ice-like masses are beautiful, and contrast with the dull gray of deep sea muds. Hydrates from the Blake... volcanoes and associated gas hydrates: Marine Geology, v. 167, p. 29-42. Milkov, A.V. and R. Sassen, 2001a, Estimate of gas hydrate resource, northwestern Gulf of Mexico continental slope: Marine Geology, v. 179, pp. 71-83. Milkov, A.V., Sassen, R...

  19. Microemulsion Synthesis of Nanoparticles

    Directory of Open Access Journals (Sweden)

    Gotić, M.

    2013-11-01

    Full Text Available Nanoparticles and nanomaterials have wide applications in electronics, physics, material design, being also utilized as sensors, catalysts, and more and more in biomedicine. Microemulsions are an exceptionally suitable medium for the synthesis of nanoparticles due to their thermodynamical stability, great solubility of both polar and nonpolar components, as well as their ability to control the size, dispersity and shape of the particles. This review presents microemulsion techniques for the synthesis of inorganic nanoparticles. It takes place in water-in-oil microemulsions by mixing one microemulsion with a cationic precursor, and the other with a precipitating or reducing agent, or by direct addition of reducing agents or gas (O2, NH3 ili CO2 into microemul sion (Fig. 1. Metal nanoparticles are used as catalysts, sensors, ferrofluids etc. They are produced by reducing the metal cation with a suitable reducing agent. In a similar way, one can prepare nanoparticles of alloys from the metal salts, provided that the metals are mutually soluble. The microemulsion technique is also suitable for depositing nanoparticles onto various surfaces. Highly active catalysts made from nanoparticles of Pt, Pd, Rh and other noble metals may be obtained in this way. Metal oxides and hydroxides may be prepared by hydrolysis or precipitation in the water core of microemulsion. Precipitation can be initiated by adding the base or precipitating agent into the microemulsion with water solution of metal ions. Similarly, nanoparticles may be prepared of sulphides, halogenides, cyanides, carbonates, sulphates and other insoluble metal salts. To prevent oxidation of nanoparticles, especially Fe, the particles are coated with inert metals, oxides, various polymers etc. Coating may provide additional functionality; e.g. coating with gold allows subsequent functionalization with organic compounds containing sulphur, due to the strong Au–S bond. Polymer coatings decrease

  20. Microporous metal organic framework [M2(hfipbb)2(ted)] (M=Zn, Co; H2hfipbb=4,4-(hexafluoroisopropylidene)-bis(benzoic acid); ted=triethylenediamine): Synthesis, structure analysis, pore characterization, small gas adsorption and CO2/N2 separation properties

    Science.gov (United States)

    Xu, William W.; Pramanik, Sanhita; Zhang, Zhijuan; Emge, Thomas J.; Li, Jing

    2013-04-01

    Carbon dioxide is a greenhouse gas that is a major contributor to global warming. Developing methods that can effectively capture CO2 is the key to reduce its emission to the atmosphere. Recent research shows that microporous metal organic frameworks (MOFs) are emerging as a promising family of adsorbents that may be promising for use in adsorption based capture and separation of CO2 from power plant waste gases. In this work we report the synthesis, crystal structure analysis and pore characterization of two microporous MOF structures, [M2(hfipbb)2(ted)] (M=Zn (1), Co (2); H2hfipbb=4,4-(hexafluoroisopropylidene)-bis(benzoic acid); ted=triethylenediamine). The CO2 and N2 adsorption experiments and IAST calculations are carried out on [Zn2(hfipbb)2(ted)] under conditions that mimic post-combustion flue gas mixtures emitted from power plants. The results show that the framework interacts with CO2 strongly, giving rise to relatively high isosteric heats of adsorption (up to 28 kJ/mol), and high adsorption selectivity for CO2 over N2, making it promising for capturing and separating CO2 from CO2/N2 mixtures.