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Sample records for synthesis gas fed

  1. 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

  2. Occurence of methanogenesis during start-up of a full-scale synthesis gas-fed reactor treating sulfate and metal-rich wastewater

    NARCIS (Netherlands)

    Houten, van B.H.G.W.; Roest, C.; Tzeneva, V.A.; Dijkman, H.; Smidt, H.; Stams, A.J.M.

    2006-01-01

    The start-up of a full-scale synthesis gas-fed gas-lift reactor treating metal and sulfate-rich wastewater was investigated. Sludge from a pilot-scale reactor was used to seed the full-scale reactor. The main difference in design between the pilot- and full-scale reactor was that metal precipitation

  3. 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.

  4. Oxygenates vs. synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Kamil Klier; Richard G. Herman; Alessandra Beretta; Maria A. Burcham; Qun Sun; Yeping Cai; Biswanath Roy

    1999-04-01

    Methanol synthesis from H{sub 2}/CO has been carried out at 7.6 MPa over zirconia-supported copper catalysts. Catalysts with nominal compositions of 10/90 mol% and 30/70 mol% Cu/ZrO{sub 2} were used in this study. Additionally, a 3 mol% cesium-doped 10/90 catalyst was prepared to study the effect of doping with heavy alkali, and this promoter greatly increased the methanol productivity. The effects of CO{sub 2} addition, water injection, reaction temperature, and H{sub 2}/C0 ratio have been investigated. Both CO{sub 2} addition to the synthesis gas and cesium doping of the catalyst promoted methanol synthesis, while inhibiting the synthesis of dimethyl ether. Injection of water, however, was found to slightly suppress methanol and dimethyl ether formation while being converted to CO{sub 2} via the water gas shift reaction over these catalysts. There was no clear correlation between copper surface area and catalyst activity. Surface analysis of the tested samples revealed that copper tended to migrate and enrich the catalyst surface. The concept of employing a double-bed reactor with a pronounced temperature gradient to enhance higher alcohol synthesis was explored, and it was found that utilization of a Cs-promoted Cu/ZnO/Cr{sub 2}O{sub 3} catalyst as a first lower temperature bed and a Cs-promoted ZnO/Cr{sub 2}O{sub 3} catalyst as a second high-temperature bed significantly promoted the productivity of 2-methyl-1-propanol (isobutanol) from H{sub 2}/CO synthesis gas mixtures. While the conversion of CO to C{sub 2+} oxygenates over the double-bed configuration was comparable to that observed over the single Cu-based catalyst, major changes in the product distribution occurred by the coupling to the zinc chromite catalyst; that is, the productivity of the C{sub 1}-C{sub 3} alcohols decreased dramatically, and 2-methyl branched alcohols were selectively formed. The desirable methanol/2-methyl oxygenate molar ratios close to 1 were obtained in the present double

  5. Effects of toluene on protein synthesis and the interaction with ethanol in hepatocytes isolated from fed and fasted rats

    International Nuclear Information System (INIS)

    Smith-Kielland, A.; Ripel, Aa.; Gadeholt, G.

    1989-01-01

    The effects of three different concentrations (about 20, 100 and 1000 μM) of toluene on protein synthesis were studied in hepatocytes isolated from fed and fasted rats after 60 and 120 min. of incubation. The interaction between ethanol (60 mM) and the low and high toluene concentrations were also tested. To measure protein synthesis, 14 C-valine was used as the precursor amino acid. Total valine concentration was 2 mM to ensure near-constant specific radioactivity of precursor. Toluene concentrations were measured by head-space gas chromatography. Protein synthesis was unchanged in the presence of low toluene concentrations. Intermediate toluene concentration decreased protein synthesis by about 20% and high toluene concentration decreased protein synthesis by about 60%. Protein synthesis was similar in cells from fed and fasted rats. Ethanol alone inhibited protein synthesis by 20-30%, more in fasted than in fed rats. Toluene and ethanol in combination inhibited protein synthesis additively. The high toluene concentration with or without ethanol appeared to inhibit synthesis/secretion of export proteins in hepatocytes from fasted rats. In conclusion, our study indicates that toluene in relatively high concentrations inhibits general protein synthesis in isolated rat hepatocytes. Toluene and ethanol seems to inhibit protein synthesis additively. (author)

  6. Synthesis gas method and apparatus

    Science.gov (United States)

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

    2013-01-08

    A method and apparatus for producing a synthesis gas product having one or more oxygen transport membrane elements thermally coupled to one or more catalytic reactors such that heat generated from the oxygen transport membrane element supplies endothermic heating requirements for steam methane reforming reactions occurring within the catalytic reactor through radiation and convention heat transfer. A hydrogen containing stream containing no more than 20 percent methane is combusted within the oxygen transport membrane element to produce the heat and a heated combustion product stream. The heated combustion product stream is combined with a reactant stream to form a combined stream that is subjected to the reforming within the catalytic reactor. The apparatus may include modules in which tubular membrane elements surround a central reactor tube.

  7. Method of production of ammonia synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    1943-09-10

    In the catalytic synthesis of complicated hydrocarbons from carbon monoxide and hydrogen at normal or slightly increased pressures by the Fischer--Tropsch process, or carried out at higher pressures in some other proposals, the synthesis gas was incompletely transformed. After the conclusion of the synthesis, the residual gas, upon the separation of the liquid constituents, contained, in addition to the unreacted carbon moxoxide and hydrogen, also considerable amounts of methane, carbon dioxide, and nitrogen from the original synthesis gas. This residual gas had been used as fuel. It was, however, pure and contained no sulfur or other catalyst poisons and burning it was considered uneconomical. It was proposed to make better use of it by using it as fuel. It was, however, pure and contained no sulfur or other catalyst poisons and burning it was considered uneconomical. It was proposed to make better use of it by using it as a raw material for the production of synthesis gas by decomposing the methane present in it with steam according to the equation CH/sub 4/ + H/sub 2/O = CO + 3H/sub 2/. This conversion was to be brought about either by a return to the producers or else in special splitting units. Also, it had been found that the residual gas, possibly even in the presence of oxygen compounds, could be conveniently used for the synthesis of ammonia. Several examples of ammonia synthesis were discussed.

  8. FEDS

    DEFF Research Database (Denmark)

    Venable, John; Pries-Heje, Jan; Baskerville, Richard

    2016-01-01

    Evaluation of design artefacts and design theories is a key activity in Design Science Research (DSR), as it provides feedback for further development and (if done correctly) assures the rigour of the research. However, the extant DSR literature provides insufficient guidance on evaluation...... to enable Design Science Researchers to effectively design and incorporate evaluation activities into a DSR project that can achieve DSR goals and objectives. To address this research gap, this research paper develops, explicates, and provides evidence for the utility of a Framework for Evaluation in Design...... Science (FEDS) together with a process to guide design science researchers in developing a strategy for evaluating the artefacts they develop within a DSR project. A FEDS strategy considers why, when, how, and what to evaluate. FEDS includes a two-dimensional characterisation of DSR evaluation episodes...

  9. Effect of ornithine on ammonia utilization and urea synthesis in isolated hepatocytes from fed rats

    International Nuclear Information System (INIS)

    Garwacki, S.; Wiechetek, M.; Souffrant, W.B.

    1988-01-01

    The effect of ornithine on the ammonia utilization and urea synthesis in hepatocytes isolated from fed male Wistar rats was investigated. On the basis of the 15 N tracer technique, it was found that ornithine stimulated urea synthesis with an increased utilization of the exogenously marked ammonia for urea, but deminished its utilization in other N-metabolic processes. The results also showed that the stimulation of urea synthesis due to ornithine resulted from the utilization of both exogenous and endogenous sources. (author)

  10. 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.

  11. 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.

  12. 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

  13. Direct dimethyl ether synthesis from synthesis gas: The influence of methanol dehydration on methanol synthesis reaction

    OpenAIRE

    Dadgar, Farbod; Myrstad, Rune; Pfeifer, Peter; Holmen, Anders; Venvik, Hilde Johnsen

    2016-01-01

    Direct dimethyl ether (DME) synthesis from synthesis gas is studied with regard to potential effects of methanol dehydration on methanol formation and copper-based catalyst performance. For this, the influence of the operating conditions (space velocity, temperature, pressure, time-on-stream and syngas composition) on activity, selectivity and stability of the catalyst was studied and compared for methanol synthesis and direct DME synthesis. The advantage of the direct over the two-step DME s...

  14. Process for preparing alkanols from synthesis gas

    International Nuclear Information System (INIS)

    Knifton, J.F.; Lin, J-J.

    1982-01-01

    Synthesis gas (carbon monoxide and hydrogen) can be converted highly selectively into alkanols, especially methanol, by reaction at a temperature of at least 150 degrees Celsius and a pressure of at least 35 bars in the presence of a catalyst comprising a ruthenium compound, a rhenium or manganese compound, and a quaternary ammonium or phosphonium compound, in the presence of an inert oxygenated solvent (ketone, ester, alcohol or preferably ether). Preferably a Group VB donor ligand, e.g. triphenyl phosphine, is also present

  15. 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.

  16. Evaluation of Reformer Produced Synthesis Gas for Emissions Reductions in Natural Gas Reciprocating Engines

    Energy Technology Data Exchange (ETDEWEB)

    Mark V. Scotto; Mark A. Perna

    2010-05-30

    Rolls-Royce Fuel Cell Systems (US) Inc. (RRFCS) has developed a system that produces synthesis gas from air and natural gas. A near-term application being considered for this technology is synthesis gas injection into reciprocating engines for reducing NOx emissions. A proof of concept study using bottled synthesis gas and a two-stroke reciprocating engine showed that injecting small amounts of highflammables content synthesis gas significantly improved combustion stability and enabled leaner engine operation resulting in over 44% reduction in NOx emissions. The actual NOx reduction that could be achieved in the field is expected to be engine specific, and in many cases may be even greater. RRFCS demonstrated that its synthesis gas generator could produce synthesis gas with the flammables content that was successfully used in the engine testing. An economic analysis of the synthesis gas approach estimates that its initial capital cost and yearly operating cost are less than half that of a competing NOx reduction technology, Selective Catalytic Reduction. The next step in developing the technology is an integrated test of the synthesis gas generator with an engine to obtain reliability data for system components and to confirm operating cost. RRFCS is actively pursuing opportunities to perform the integrated test. A successful integrated test would demonstrate the technology as a low-cost option to reduce NOx emissions from approximately 6,000 existing two-stroke, natural gas-fired reciprocating engines used on natural gas pipelines in North America. NOx emissions reduction made possible at a reasonable price by this synthesis gas technology, if implemented on 25% of these engines, would be on the order of 25,000 tons/year.

  17. Evaluation of Reformer Produced Synthesis Gas for Emissions Reductions in Natural Gas Reciprocating Engines

    Energy Technology Data Exchange (ETDEWEB)

    Mark Scotto

    2010-05-30

    Rolls-Royce Fuel Cell Systems (US) Inc. (RRFCS) has developed a system that produces synthesis gas from air and natural gas. A near-term application being considered for this technology is synthesis gas injection into reciprocating engines for reducing NO{sub x} emissions. A proof of concept study using bottled synthesis gas and a two-stroke reciprocating engine showed that injecting small amounts of high-flammable content synthesis gas significantly improved combustion stability and enabled leaner engine operation resulting in over 44% reduction in NO{sub x} emissions. The actual NO{sub x} reduction that could be achieved in the field is expected to be engine specific, and in many cases may be even greater. RRFCS demonstrated that its synthesis gas generator could produce synthesis gas with the flammable content that was successfully used in the engine testing. An economic analysis of the synthesis gas approach estimates that its initial capital cost and yearly operating cost are less than half that of a competing NO{sub x} reduction technology, Selective Catalytic Reduction. The next step in developing the technology is an integrated test of the synthesis gas generator with an engine to obtain reliability data for system components and to confirm operating cost. RRFCS is actively pursuing opportunities to perform the integrated test. A successful integrated test would demonstrate the technology as a low-cost option to reduce NO{sub x} emissions from approximately 6,000 existing two-stroke, natural gas-fired reciprocating engines used on natural gas pipelines in North America. NO{sub x} emissions reduction made possible at a reasonable price by this synthesis gas technology, if implemented on 25% of these engines, would be on the order of 25,000 tons/year.

  18. Integrated production of fuel gas and oxygenated organic compounds from synthesis gas

    Science.gov (United States)

    Moore, Robert B.; Hegarty, William P.; Studer, David W.; Tirados, Edward J.

    1995-01-01

    An oxygenated organic liquid product and a fuel gas are produced from a portion of synthesis gas comprising hydrogen, carbon monoxide, carbon dioxide, and sulfur-containing compounds in a integrated feed treatment and catalytic reaction system. To prevent catalyst poisoning, the sulfur-containing compounds in the reactor feed are absorbed in a liquid comprising the reactor product, and the resulting sulfur-containing liquid is regenerated by stripping with untreated synthesis gas from the reactor. Stripping offgas is combined with the remaining synthesis gas to provide a fuel gas product. A portion of the regenerated liquid is used as makeup to the absorber and the remainder is withdrawn as a liquid product. The method is particularly useful for integration with a combined cycle coal gasification system utilizing a gas turbine for electric power generation.

  19. Laser-induced breakdown ignition in a gas fed two-stroke engine

    Science.gov (United States)

    Loktionov, E. Y.; Pasechnikov, N. A.; Telekh, V. D.

    2018-01-01

    Laser-induced ignition for internal combustion engines is investigated intensively after demonstration of a compact ‘laser plug’ possibility. Laser spark benefits as compared to traditional spark plugs are higher compression rate, and possibility of almost any fuel ignition, so lean mixtures burning with lower temperatures could reduce harmful exhausts (NO x , CH, etc). No need in electrode and possibility for multi-point, linear or circular ignition can make combustion even more effective. Laser induced combustion wave appears faster and is more stable in time, than electric one, so can be used for ramjets, chemical thrusters, and gas turbines. To the best of our knowledge, we have performed laser spark ignition of a gas fed two-stroke engine for the first time. Combustion temperature and pressure, exhaust composition, ignition timing were investigated at laser and compared to a regular electric spark ignition in a two-stroke model engine. Presented results show possibility for improvement of two-stroke engines performance, in terms of rotation rate increase and NO x emission reduction. Such compact engines using locally mined fuel could be highly demanded in remote Arctic areas.

  20. 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...

  1. Effect of Sulfide Removal on Sulfate Reduction at pH 5 in a Hydrogen fed Gas-Lift Bioreactor

    NARCIS (Netherlands)

    Bijmans, M.F.M.; Dopson, M.; Lens, P.N.L.; Buisman, C.J.N.

    2008-01-01

    UNCORRECTED PROOF J. Microbiol. Biotechnol. (2007), 17(4), ¿ Effect of Sulfide Removal on Sulfate Reduction at pH 5 in a Hydrogen fed Gas-Lift Bioreactor Bijmans, Martijn F. M.1*, Mark Dopson2, Frederick Ennin1, Piet N. L. Lens1, and Cees J. N. Buisman1 1Sub Department of Environmental Technology,

  2. 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 ...

  3. Activation of catalysts for synthesizing methanol from synthesis gas

    Science.gov (United States)

    Blum, David B.; Gelbein, Abraham P.

    1985-01-01

    A method for activating a methanol synthesis catalyst is disclosed. In this method, the catalyst is slurried in an inert liquid and is activated by a reducing gas stream. The activation step occurs in-situ. That is, it is conducted in the same reactor as is the subsequent step of synthesizing methanol from a methanol gas stream catalyzed by the activated catalyst still dispersed in a slurry.

  4. Microbiology of synthesis gas fermentation for biofuel production

    NARCIS (Netherlands)

    Henstra, A.M.; Sipma, J.; Rinzema, A.; Stams, A.J.M.

    2007-01-01

    A significant portion of biomass sources like straw and wood is poorly degradable and cannot be converted to biofuels by microorganisms. The gasification of this waste material to produce synthesis gas (or syngas) could offer a solution to this problem, as microorganisms that convert CO and H2 (the

  5. Manure ammonia and greenhouse gas emissions from beef cattle fed condensed tannins

    Science.gov (United States)

    A study was conducted to determine the effects of three levels of condensed tannins fed to 27 beef feed yard steers on ammonia and GHG emissions from manure. Condensed tannins were fed at rates of 0, 0.5 and 1.0 percent on a dry matter basis. Manure and urine were collected from two periods over 6 d...

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

    Indian Academy of Sciences (India)

    Unknown

    fuel cells (Gross et al 1998a; Verges et al 2000). It has promising application as a chemical gas sensor (Nagai et al. 1988; Gross et al 1998a; Verges et al 2000). ... Spec-pure grade calcium nitrate, di-ammonium hydrogen phosphate, ammonium hydroxide and calcium hydroxide were used as the starting chemicals.

  7. 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.

  8. 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.

  9. 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.

  10. Production of biofuels from synthesis gas using microbial catalysts.

    Science.gov (United States)

    Tirado-Acevedo, Oscar; Chinn, Mari S; Grunden, Amy M

    2010-01-01

    World energy consumption is expected to increase 44% in the next 20 years. Today, the main sources of energy are oil, coal, and natural gas, all fossil fuels. These fuels are unsustainable and contribute to environmental pollution. Biofuels are a promising source of sustainable energy. Feedstocks for biofuels used today such as grain starch are expensive and compete with food markets. Lignocellulosic biomass is abundant and readily available from a variety of sources, for example, energy crops and agricultural/industrial waste. Conversion of these materials to biofuels by microorganisms through direct hydrolysis and fermentation can be challenging. Alternatively, biomass can be converted to synthesis gas through gasification and transformed to fuels using chemical catalysts. Chemical conversion of synthesis gas components can be expensive and highly susceptible to catalyst poisoning, limiting biofuel yields. However, there are microorganisms that can convert the CO, H(2), and CO(2) in synthesis gas to fuels such as ethanol, butanol, and hydrogen. Biomass gasification-biosynthesis processing systems have shown promise as some companies have already been exploiting capable organisms for commercial purposes. The discovery of novel organisms capable of higher product yield, as well as metabolic engineering of existing microbial catalysts, makes this technology a viable option for reducing our dependency on fossil fuels. Copyright 2010 Elsevier Inc. All rights reserved.

  11. Biological conversion of synthesis gas. Topical report: Economic evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Clausen, E.C.; Gaddy, J.L.

    1993-09-01

    The purpose of the proposed research is to develop a technically and economically feasible process for biologically producing H{sub 2} from synthesis gas while, at the same time, removing harmful sulfur gas compounds. Six major tasks are being studied: culture development, where the best cultures are selected and conditions optimized for simultaneous hydrogen production and sulfur gas removal; mass transfer and kinetic studies in which equations necessary for process design are developed; bioreactor design studies, where the cultures chosen in Task 1 are utilized in continuous reaction vessels to demonstrate process feasibility and define operating conditions; evaluation of biological synthesis gas conversion under limiting conditions in preparation for industrial demonstration studies; process scale-up where laboratory data are scaled to larger-size units in preparation for process demonstration in a pilot-scale unit; and economic evaluation, where process simulations are used to project process economics and identify high cost areas during sensitivity analyses. The purpose of this report is to present economic evaluations for H{sub 2} production from synthesis gone by Rhodospirillum rubrum. Cases are presented with and without light requirements and in stirred tank and immobilized cell reactors. In addition, economic information is presented for isolate ERIH{sub 2} (from Engineering Resources, Inc.) in the two reactors with and without H{sub 2} recovery.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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

  1. Novel reactor configuration for synthesis gas conversion to alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Akgerman, A.; Anthony, R.G.

    1990-01-01

    Research continued on the design of a chemical reactor for synthesis gas conversion. During the second quarter our objective was to continue with Task 2 and start on Task 3. Task 2 involved standardization and automation of GC analysis protocols. Task 3, as stated in the work breakdown schedule, was the modification and automation of the trickle bed reactor and performing the initial factorial design experiments. We have decided to modify this task by expanding it to incorporate determination of the hydrodynamic and transport parameters of the trickle bed reactor in order to isolate and study just the reaction parameters. 1 fig.

  2. Growth of a Massive Young Stellar Object Fed by a Gas Flow from a Companion Gas Clump

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xi; Shen, Zhiqiang [Shanghai Astronomical Observatories, Chinese Academy of Science, Nandan Rd. 80, Shanghai (China); Ren, Zhiyuan [National Astronomical Observatories, Chinese Academy of Science, Chaoyang District Datun Rd. A20, Beijing (China); Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 (United States); Qiu, Keping [School of Astronomy and Space Science, Nanjing University, 22 Hankou Rd., Nanjing, Jiangsu 210093 (China)

    2017-02-01

    We present a Submillimeter Array (SMA) observation toward the young massive double-core system G350.69-0.49. This system consists of a northeast (NE) diffuse gas bubble and a southwest (SW) massive young stellar object (MYSO), both clearly seen in the Spitzer images. The SMA observations reveal a gas flow between the NE bubble and the SW MYSO in a broad velocity range from 5 to 30 km s{sup −1} with respect to the system velocity. The gas flow is well confined within the interval between the two objects and traces a significant mass transfer from the NE gas bubble to the SW massive core. The transfer flow can supply the material accreted onto the SW MYSO at a rate of 4.2×10{sup −4} M{sub ⊙} yr{sup −1}. The whole system therefore suggests a mode for the mass growth in the MYSO from a gas transfer flow launched from its companion gas clump, despite the driving mechanism of the transfer flow not being fully determined from the current data.

  3. 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.

  4. Decreased rate of protein synthesis, caspase-3 activity, and ubiquitin-proteasome proteolysis in soleus muscles from growing rats fed a low-protein, high-carbohydrate diet.

    Science.gov (United States)

    Batistela, Emanuele; Pereira, Mayara Peron; Siqueira, Juliany Torres; Paula-Gomes, Silvia; Zanon, Neusa Maria; Oliveira, Eduardo Brandt; Navegantes, Luiz Carlos Carvalho; Kettelhut, Isis C; Andrade, Claudia Marlise Balbinotti; Kawashita, Nair Honda; Baviera, Amanda Martins

    2014-06-01

    The aim of this study was to investigate the changes in the rates of both protein synthesis and breakdown, and the activation of intracellular effectors that control these processes in soleus muscles from growing rats fed a low-protein, high-carbohydrate (LPHC) diet for 15 days. The mass and the protein content, as well as the rate of protein synthesis, were decreased in the soleus from LPHC-fed rats. The availability of amino acids was diminished, since the levels of various essential amino acids were decreased in the plasma of LPHC-fed rats. Overall rate of proteolysis was also decreased, explained by reductions in the mRNA levels of atrogin-1 and MuRF-1, ubiquitin conjugates, proteasome activity, and in the activity of caspase-3. Soleus muscles from LPHC-fed rats showed increased insulin sensitivity, with increased levels of insulin receptor and phosphorylation levels of AKT, which probably explains the inhibition of both the caspase-3 activity and the ubiquitin-proteasome system. The fall of muscle proteolysis seems to represent an adaptive response that contributes to spare proteins in a condition of diminished availability of dietary amino acids. Furthermore, the decreased rate of protein synthesis may be the driving factor to the lower muscle mass gain in growing rats fed the LPHC diet.

  5. Exergy Analysis of an Intermediate Temperature Solid Oxide Fuel Cell-Gas Turbine Hybrid System Fed with Ethanol

    Directory of Open Access Journals (Sweden)

    Fotini Tzorbatzoglou

    2012-10-01

    Full Text Available In the present work, an ethanol fed Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT system has been parametrically analyzed in terms of exergy and compared with a single SOFC system. The solid oxide fuel cell was fed with hydrogen produced from ethanol steam reforming. The hydrogen utilization factor values were kept between 0.7 and 1. The SOFC’s Current-Volt performance was considered in the range of 0.1–3 A/cm2 at 0.9–0.3 V, respectively, and at the intermediate operating temperatures of 550 and 600 °C, respectively. The curves used represent experimental results obtained from the available bibliography. Results indicated that for low current density values the single SOFC system prevails over the SOFC-GT hybrid system in terms of exergy efficiency, while at higher current density values the latter is more efficient. It was found that as the value of the utilization factor increases the SOFC system becomes more efficient than the SOFC-GT system over a wider range of current density values. It was also revealed that at high current density values the increase of SOFC operation temperature leads in both cases to higher system efficiency values.

  6. Sugar Synthesis from a Gas-Phase Formose Reaction

    Science.gov (United States)

    Jalbout, Abraham F.; Abrell, Leif; Adamowicz, Ludwik; Polt, Robin; Apponi, A. J.; Ziurys, L. M.

    2007-06-01

    Prebiotic possibilities for the synthesis of interstellar ribose through a protic variant of the formose reaction under gas-phase conditions were studied in the absence of any known catalyst. The ion-molecule reaction products, diose and triose, were sought by mass spectrometry, and relevant masses were observed. Ab initio calculations were used to evaluate protic formose mechanism possibilities. A bilateral theoretical and experimental effort yielded a physical model for glycoaldehyde generation whereby a hydronium cation can mediate formaldehyde dimerization followed by covalent bond formation leading to diose and water. These results advance the possibility that ion-molecule reactions between formaldehyde (CH2O) and H3O+ lead to formose reaction products and inform us about potential sugar formation processes in interstellar space.

  7. Nitrogen balance, microbial protein synthesis and blood metabolites in fattening of male Bali cattle fed ration with different protein levels in smallholder farms

    Directory of Open Access Journals (Sweden)

    P. K. Tahuk

    2018-03-01

    Full Text Available Research was aimed to determine nitrogen balance, microbial protein synthesis, and blood metabolites of male Bali cattle fattening fed ration with different protein level in smallholder farms North Central Timor, Province of East Timor Tenggara, Indonesia. The cattle used were 18 heads aged 2 to 2.5 years with initial body weight of 229.86±12.46 kg. The cattle were randomly divided into three treatment groups. The T0 group was given feed the same as traditional fattening cattle practices by farmers,T1 group fed ration containing 12% crude protein (CP and 72% total digestible nutrients (TDN, andT2 group fedration containing 15% CP and 72%TDN. Cattle were fed individually for 90 days and drinkingwater ad libitum. The data were analyzedby analysis of variance.Results of research indicated the nitrogen balance, and blood urea nitrogen between T1 and T2 were relatively similar, but those were higher (P<0.05 than T0 . In contrast, microbial proteins synthesis, and blood glucose at 0, 4, and 6 hours before and after feeding were relatively similar between the groups. Blood glucose of T2 at 2 hours after intake were higher (P <0.05 than T0, but was not different with T1 . It can be concluded, that the fattening maleBali cattle fed ration containing 12% CP and 72% TDNimprovedthe nitrogen balance and blood metabolites, butit was no positive effect on the microbial proteins and N synthesis.

  8. 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.

  9. Bioconversion of coal derived synthesis gas to liquid fuels

    Science.gov (United States)

    Jain, M. K.; Worden, R. M.; Grethlein, A.

    1994-07-01

    The overall objective of the project is to develop an integrated two-stage fermentation process for conversion of coal-derived synthesis gas to a mixture of alcohols. This is achieved in two steps. In the first step, Butyribacterium methylotrophicum converts carbon monoxide (CO) to butyric and acetic acids. Subsequent fermentation of the acids by Clostridium acetobutylicum leads to the production of butanol and ethanol. The tasks for this quarter were: development/isolation of superior strains for fermentation of syngas; evaluation of bioreactor configuration for improved mass transfer of syngas; recovery of carbon and electrons from H2-CO2; initiation of pervaporation for recovery of solvents; and selection of solid support material for trickle-bed fermentation. Technical progress included the following: butyrate production was enhanced during H2/CO2 (50/50) batch fermentation; isolation of CO-utilizing anaerobic strains is in progress; pressure (15 psig) fermentation was evaluated as a means of increasing CO availability; polyurethane foam packing material was selected for trickle bed solid support; cell recycle fermentation on syngas operated for 3 months. Acetate was the primary product at pH 6.8; trickle bed and gas lift fermentor designs were modified after initial water testing; and pervaporation system was constructed (No alcohol selectivity was shown with the existing membranes during initial start-up).

  10. Nutrient digestion, microbial protein synthesis, and blood metabolites of Jersey heifers fed chitosan and whole raw soybeans

    Directory of Open Access Journals (Sweden)

    Jefferson Rodrigues Gandra

    2016-03-01

    Full Text Available ABSTRACT This study was undertaken to determine the effects of chitosan and whole raw soybean on nutrient intake and total tract digestion, nitrogen utilization, microbial protein synthesis, blood metabolites, and energy balance of dairy heifers. Twelve Jersey heifers (6±0.5 months of age and 139.50±25.56 kg of live weight; mean ± standard deviation were randomly assigned to a replicated Latin square design with a 2 × 2 factorial arrangement. The experimental period consisted of 14 days of adaptation to diets, six days of sampling, and five days of washout. The experimental diets were: control (CO; chitosan (CHI, inclusion of 2.0 g kg−1 DM of chitosan; whole raw soybean (WS, 163.0 g kg−1 of WS on diet DM basis; and chitosan + whole raw soybean (CHI+WS. Chitosan decreased dry matter and neutral detergent fiber intakes; however, CHI increased DM total tract digestion. An interaction effect was observed on retained nitrogen, which increased when animals were fed CHI+WS compared with CO or CHI, but did not differ from that of animals fed WS. Chitosan decreased microbial nitrogen and crude protein flow of heifers. Energy balance was improved when heifers received diets containing WS. Efficiency of energy utilization was not affected by experimental diets. An interaction effect was observed for blood high-density lipoprotein (HDL concentration, which increased with both dietary inclusion of CHI and WS compared with the other diets, and CHI provided the lowest value of HDL cholesterol. Chitosan and whole raw soybean do not alter nutrient intake and total tract digestion; however, they decrease nitrogen urinary excretion and increase blood HDL cholesterol of heifers.

  11. Nuclear techniques to determine microbial protein synthesis and productive performance of barki lambs fed rations containing some medicinal plants

    International Nuclear Information System (INIS)

    Mohamed, M.M.S.

    2009-01-01

    This study included two experiments, the first experiment was carried out in vitro to evaluate the effect of adding two levels of Lemongrass or Rosemary in ruminant rations on microbial protein synthesis using radio active sulfur S 35 . While, the second experiment was to study the effect of Lemongrass (CC) and Rosemary (RO) as feed additives in rations of lambs on feed intake, nutrient digestibility, some parameters of blood and rumen activity. Meanwhile, body weight and economical efficiency were studied. Twenty five of Barki male lambs with average body weight of 19.8 kg ± 1 kg and 3- 4 months of age were divided into 5 similar groups (5 lambs each). The first group (control) (R1) was fed on a concentrate feed mixture (CFM) plus rice straw (RS). While, R2 and R3 were fed as R1 ration supplemented with 100 or 200 mg Lemongrass /kg LBW/d respectively. Meantime, R4 and R5 were fed as R1 ration supplemented with 100 or 200 mg Rosemary /kg LBW/d respectively.The results indicated that more microbial protein synthesis was noticed with 4 mg of Lemongrass followed by 2 mg Rosemary, 2 mg Lemongrass and control which was higher than 4 mg Rosemary/ 0.5 g concentrate mixture. The differences were not statistically significant. The dry matter intake (DMI) was not significantly different for R4 and R3 when compared with R1 (control) and it significantly decreased in R5 and R2 compared with R1. The digestibilities of DM, OM, CP, EE and NFE in the supplemented groups were not significantly differing compared with R1. The digestibility of CF was significantly increased in R2 and R4 compared with R1 and there were no significant differences for R3 and R5 compared with R1. There were no significant differences in nutritive values as TDN, DCP and SV among all supplemented groups compared with R1. Rumen liquor TVFA,s was not significantly differ at zero time, but it decreased at 3 h and 6 h with all additives compared with the control with no significant differences among all

  12. 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

  13. Exploring biochemical pathways for mono-ethylene glycol (MEG) synthesis from synthesis gas.

    Science.gov (United States)

    Islam, M Ahsanul; Hadadi, Noushin; Ataman, Meric; Hatzimanikatis, Vassily; Stephanopoulos, Gregory

    2017-05-01

    Mono-ethylene glycol (MEG) is an important petrochemical with widespread use in numerous consumer products. The current industrial MEG-production process relies on non-renewable fossil fuel-based feedstocks, such as petroleum, natural gas, and naphtha; hence, it is useful to explore alternative routes of MEG-synthesis from gases as they might provide a greener and more sustainable alternative to the current production methods. Technologies of synthetic biology and metabolic engineering of microorganisms can be deployed for the expression of new biochemical pathways for MEG-synthesis from gases, provided that such promising alternative routes are first identified. We used the BNICE.ch algorithm to develop novel and previously unknown biological pathways to MEG from synthesis gas by leveraging the Wood-Ljungdahl pathway of carbon fixation of acetogenic bacteria. We developed a set of useful pathway pruning and analysis criteria to systematically assess thousands of pathways generated by BNICE.ch. Published genome-scale models of Moorella thermoacetica and Clostridium ljungdahlii were used to perform the pathway yield calculations and in-depth analyses of seven (7) newly developed biological MEG-producing pathways from gases, including CO 2 , CO, and H 2 . These analyses helped identify not only better candidate pathways, but also superior chassis organisms that can be used for metabolic engineering of the candidate pathways. The pathway generation, pruning, and detailed analysis procedures described in this study can also be used to develop biochemical pathways for other commodity chemicals from gaseous substrates. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  14. In vitro methane and gas production with inocula from cows and goats fed an identical diet.

    Science.gov (United States)

    Mengistu, Genet; Hendriks, Wouter H; Pellikaan, Wilbert F

    2018-03-01

    Fermentative capacity among ruminants can differ depending on the type of ruminant species and the substrate fermented. The aim was to compare in vitro cow and goat rumen inocula in terms of methane (CH 4 ) and gas production (GP), fermentation kinetics and 72 h volatile fatty acids (VFA) production using the browse species Acacia etbaica, Capparis tomentosa, Dichrostachys cinerea, Rhus natalensis, freeze-dried maize silage and grass silage, and a concentrate as substrates. Total GP, CH 4 and VFA were higher (P ≤ 0.008) in goat inoculum than cows across substrates. The half-time for asymptotic GP was lower (P Methane production and as a percentage of total GP was higher (P < 0.0001) and the half-time tended (P = 0.059) to be at a later time for goats compared to cows. Goat inoculum showed higher fermentative activity with a concomitant higher CH 4 production compared to cows. This difference highlights the ability of goats to better utilise browse species and other roughage types. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. Microbial protein synthesis and concentration of urea in dairy heifers fed diets with cactus forage Opuntia

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Mercês Aguiar

    2015-04-01

    Full Text Available The objective was to analyze the influence of increasing levels of forage cactus Opuntia in the diet on the nitrogen balance, the concentrations of urea in urine and plasma and microbial protein synthesis in dairy heifers ¾ Holstein-zebu confined. twenty four heifers were used with initial body weight of 163.00 ± 18 kg, with 8 months old and distributed in a completely randomized design with four treatments and six replications. It was used sorghum silage, concentrate and increasing levels of forage cactus Opuntia in the diet (0, 200, 400 and 600 g kg-1. The nitrogen intake, feces and urine, digested and retained with the addition of forage cactus in the diet showed decreasing linear effect. Nitrogen balance was influenced by the inclusion of forage cactus in the diet of dairy heifers through the values observed for the digested and retained nitrogen, which can be related to similar effects found for the consumption of nitrogen and the nitrogen excretion in feces and urine. Nitrogen digested percentage of intake and nitrogen retention as a percentage of ingested and digested showed no difference with the inclusion of forage cactus in the diet. The concentration of urea nitrogen in the urine of heifers had a quadratic effect point of maximum excretion level of 275.80 g kg-1 of forage cactus in the diet. Consequently, the excretion of urea nitrogen and urea excretion showed similar effect with maximum points excretion levels of 293.75 and 319.00 g kg-1 of forage in the diet. The concentration of ureic nitrogen in plasma showed no difference, with an average value of 13.19 mg dL-1. Synthesis of nitrogen and microbial crude protein adjusted to the quadratic model. The microbial efficiency was not influenced by the inclusion of forage cactus in replacement of sorghum silage and concentrate. The urine volume similar to the treatments, with an average of 5.90 liters of urine per day, proving that the creatinine excretion in urine was not influenced

  16. QUANTIFICATION OF THE EFFICIENCY OF RUMEN MICROBIAL PROTEIN SYNTHESIS IN STEERS FED GREEN TROPICAL GRASS

    Directory of Open Access Journals (Sweden)

    MARTHEN L. MULLIK

    2012-09-01

    Full Text Available ABSTRACT The rate of rumen microbial crude protein (MCP supply to the intestines is a crucial element in the current rumen models to predict respond of ruminants to a certain diet. Data from tropical pastures always below predicted results from the existing rumen models. Thus, quantification of the rumen MCP supply from tropical grass will improve predictive rate under tropical feeding conditions. Four Brahman crossbred steers (457±20.1 kg were used in a metabolism study. Pangola grass (Digitaria erianthe cv. Steudal was harvested every morning and fed to the animals soon after. Parameters measured were EMPS, intake, fractional passage rates, and rumen ammonia concentration. The EMPS was estimated using purine derivative excretion in urine. Crude protein and water soluble carbohydrates content were 6.3 and 7.4% of dry matter (DM respectively. DM intake was 1.6% live weight. Average rumen ammonia concentration was 69 mg/L whilst rumen passage rates were 7.84 and 6.92 %/h for fluid and solids respectively. EMPS was only 72 g MCP/kg digestible organic matter. It might be concluded that EMPS in steers consuming green pangola grass was below the minimum level for forage diets adopted in the current feeding standards. ABSTRAK Tingkat pasokan protein mikroba rumen (MCP ke usus halus merupakan salah satu unsur kunci dalam meramal respon pertumbuhan ruminan terhadap ransum tertentu. Data MCP hijauan tropis selalu berada di bawah nilai prediksi model rumen yang dipakai saat ini. Dengan demikian, kuantifikasi pasokan MCP rumput tropis diharapkan menjadi masukan untuk meningkatkan kemampuan prediksi model rumen untuk pakan daerah tropis. Empat sapi jantan muda Brahman persilangan (457±20,1 kg digunakan dalam sebuah penelitian metabolisme. Rumput pangola (Digitaria erianthe cv. Steudal dipanen setiap pagi dan langsung diberikan kepada ternak dalam kandang metabolis. Parameter yang diukur adalah produksi MCP dan efisiensi sintesis MCP (Emps, konsumsi, laju

  17. Germanium-silicon alloy and core-shell nanocrystals by gas phase synthesis.

    Science.gov (United States)

    Mehringer, Christian; Kloner, Christian; Butz, Benjamin; Winter, Benjamin; Spiecker, Erdmann; Peukert, Wolfgang

    2015-03-12

    In this work we present a novel route to synthesize well defined germanium-silicon alloy (GexSi1-x) and core-shell nanocrystals (NCs) employing monosilane (SiH4) and monogermane (GeH4) as precursors in a continuously operated two-stage hot-wall aerosol reactor setup. The first hot-wall reactor stage (HWR I) is used to produce silicon (Si) seed particles from SiH4 pyrolysis in Argon (Ar). The resulting seeding aerosol is fed into the second reactor stage (HWR II) and a mixture of SiH4 and GeH4 is added. The ratio of the precursors in the feed, their partial pressures, the synthesis temperature in HWR II and the overall pressure are varied depending on the desired morphology and composition. Alloy particle production is achieved in the heterogeneous surface reaction regime, meaning that germanium (Ge) and Si are deposited on the seed surface simultaneously. The NCs can be synthesized with any desired composition, whilst maintaining a mean diameter around 30 nm with a geometric standard deviation (GSD) around 1.25. The absorption behavior and the related fundamental optical band gap energy in dependence on the alloy composition are exemplarily presented. They prove the possibility to tailor NC properties for electronical and opto-electronical applications. In the homogeneous gas phase reaction regime facetted Ge-Si core-shell structures are accessible. The Ge deposition on the seeds precedes the Si deposition due to different gas phase reaction kinetics of the precursors. The Si layer grows epitaxially on the Ge core and is around 5 nm thick.

  18. Nickel-containing catalysts for methane oxidation to synthesis gas

    Directory of Open Access Journals (Sweden)

    Kusman Dossumov

    2014-12-01

    Full Text Available The partial oxidation of methane to synthesis gas was studied on oxides of metals of variable valence (Mn, La, Cr and Ni, supported on a carrier – ɣ-Al2O3. Among the catalysts studied, the sample of 3% Ni/ɣ-Al2O3 showed the best characteristics by yields of hydrogen and carbon monoxide in the reaction of partial oxidation of methane. The optimal conditions of the process (the reaction temperature of 850 °C, the volume rate of 4500 h-1, and the ratio CH4: O2 = 2:1 cause the increase the concentration of hydrogen and carbon monoxide to 72.2 and 75.3%, respectively. The effect of the heat-treatment temperature and textural characteristics of the Ni/ ɣ-Al2O3 catalyst on its catalytic activity was studied. The NiCe/Al2O3 catalyst developed showed a high stability during 30 hours.

  19. 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.

  20. 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.

  1. 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.

  2. Greenhouse Gas Emissions from Calf- and Yearling-Fed Beef Production Systems, With and Without the Use of Growth Promotants

    Directory of Open Access Journals (Sweden)

    Erasmus Okine

    2012-04-01

    Full Text Available A spring calving herd consisting of about 350 beef cows, 14–16 breeding bulls, 60 replacement heifers and 112 steers were used to compare the whole-farm GHG emissions among calf-fed vs. yearling-fed production systems with and without growth implants. Carbon footprint ranged from 11.63 to 13.22 kg CO2e per kg live weight (19.87–22.52 kg CO2e per kg carcass weight. Enteric CH4 was the largest source of GHG emissions (53–54%, followed by manure N2O (20–22%, cropping N2O (11%, energy use CO2 (9–9.5%, and manure CH4 (4–6%. Beef cow accounted for 77% and 58% of the GHG emissions in the calf-fed and yearling-fed. Feeders accounted for the second highest GHG emissions (15% calf-fed; 35–36% yearling-fed. Implants reduced the carbon footprint by 4.9–5.1% compared with hormone-free. Calf-fed reduced the carbon footprint by 6.3–7.5% compared with yearling-fed. When expressed as kg CO2e per kg carcass weight per year the carbon footprint of calf-fed production was 73.9–76.1% lower than yearling-fed production, and calf-fed implanted was 85% lower than hormone-free yearling-fed. Reducing GHG emissions from beef production may be accomplished by improving the feed efficiency of the cow herd, decreasing the days on low quality feeds, and reducing the age at harvest of youthful cattle.

  3. 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.

  4. 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.

  5. 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)

    NONE

    1998-05-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through April 1998.

  6. Momordica charantia ameliorates insulin resistance and dyslipidemia with altered hepatic glucose production and fatty acid synthesis and AMPK phosphorylation in high-fat-fed mice.

    Science.gov (United States)

    Shih, Chun-Ching; Shlau, Min-Tzong; Lin, Cheng-Hsiu; Wu, Jin-Bin

    2014-03-01

    Momordica charantia Linn. (Cucurbitaceae) fruit is commonly known as bitter melon. C57BL/6J mice were firstly divided randomly into two groups: the control (CON) group was fed with a low-fat diet, whereas the experimental group was fed a 45% high-fat (HF) diet for 8 weeks. Afterwards, the CON group was treated with vehicle, whereas the HF group was subdivided into five groups and still on HF diet and was given orally M. charantia extract (MCE) or rosiglitazone (Rosi) or not for 4 weeks. M. charantia decreased the weights of visceral fat and caused glucose lowering. AMP-activated protein kinase (AMPK) is a major cellular regulator of lipid and glucose metabolism. MCE significantly increases the hepatic protein contents of AMPK phosphorylation by 126.2-297.3% and reduces expression of phosphenolpyruvate carboxykinase (PEPCK) and glucose production. Most importantly, MCE decreased expression of hepatic 11beta hydroxysteroid dehydroxygenase (11beta-HSD1) gene, which contributed in attenuating diabetic state. Furthermore, MCE lowered serum triglycerides (TGs) by inhibition of hepatic fatty acid synthesis by dampening sterol response element binding protein 1c and fatty acid synthase mRNA leading to reduction in TGs synthesis. This study demonstrates M. charantia ameliorates diabetic and hyperlipidemic state in HF-fed mice occurred by regulation of hepatic PEPCK, 11beta-HSD1 and AMPK phosphorylation. Copyright © 2013 John Wiley & Sons, Ltd.

  7. Incoporating Ammonia Synthesis for an Offshore Gas-to-Liquid Process

    OpenAIRE

    Lundgren, Mathias Kristoffer

    2016-01-01

    The world energy demand is increasing, and so is the demand for fertilizer to sustain an exponential population growth. Currently, with low oil prices, asso- ciated natural gas is flared off or re-injected into oil reservoirs for enhanced oil recovery (EOR). A gas-to-liquid process (GTL) for offshore applications aboard a foating production, storage, and offoading vessel (FPSO) incorpo- rating Fischer-Tropsch Synthesis (FTS) seeks to reform natural gas into more valuable liq...

  8. 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

  9. Synthesis Gas (Syngas)-Derived Medium-Chain-Length Polyhydroxyalkanoate Synthesis in Engineered Rhodospirillum rubrum.

    Science.gov (United States)

    Heinrich, Daniel; Raberg, Matthias; Fricke, Philipp; Kenny, Shane T; Morales-Gamez, Laura; Babu, Ramesh P; O'Connor, Kevin E; Steinbüchel, Alexander

    2016-10-15

    The purple nonsulfur alphaproteobacterium Rhodospirillum rubrum S1 was genetically engineered to synthesize a heteropolymer of mainly 3-hydroxydecanoic acid and 3-hydroxyoctanoic acid [P(3HD-co-3HO)] from CO- and CO 2 -containing artificial synthesis gas (syngas). For this, genes from Pseudomonas putida KT2440 coding for a 3-hydroxyacyl acyl carrier protein (ACP) thioesterase (phaG), a medium-chain-length (MCL) fatty acid coenzyme A (CoA) ligase (PP_0763), and an MCL polyhydroxyalkanoate (PHA) synthase (phaC1) were cloned and expressed under the control of the CO-inducible promoter P cooF from R. rubrum S1 in a PHA-negative mutant of R. rubrum P(3HD-co-3HO) was accumulated to up to 7.1% (wt/wt) of the cell dry weight by a recombinant mutant strain utilizing exclusively the provided gaseous feedstock syngas. In addition to an increased synthesis of these medium-chain-length PHAs (PHA MCL ), enhanced gene expression through the P cooF promoter also led to an increased molar fraction of 3HO in the synthesized copolymer compared with the P lac promoter, which regulated expression on the original vector. The recombinant strains were able to partially degrade the polymer, and the deletion of phaZ2, which codes for a PHA depolymerase most likely involved in intracellular PHA degradation, did not reduce mobilization of the accumulated polymer significantly. However, an amino acid exchange in the active site of PhaZ2 led to a slight increase in PHA MCL accumulation. The accumulated polymer was isolated; it exhibited a molecular mass of 124.3 kDa and a melting point of 49.6°C. With the metabolically engineered strains presented in this proof-of-principle study, we demonstrated the synthesis of elastomeric second-generation biopolymers from renewable feedstocks not competing with human nutrition. Polyhydroxyalkanoates (PHAs) are natural biodegradable polymers (biopolymers) showing properties similar to those of commonly produced petroleum-based nondegradable polymers. The

  10. 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.

  11. Triglyceride synthesis in hepatocytes isolated from rats fed a low-protein diet is enhanced independently of upregulation of insulin signaling.

    Science.gov (United States)

    Taguchi, Yusuke; Toyoshima, Yuka; Tokita, Reiko; Kato, Hisanori; Takahashi, Shin-Ichiro; Minami, Shiro

    2017-08-26

    It is known that protein malnutrition develops fatty liver in rats. However, the mechanisms by which protein malnutrition enhances lipid accumulation in the liver are not fully understood. Our previous studies have demonstrated that protein malnutrition upregulates insulin signaling with an increase in TG levels in rat livers. Here, we examined whether the upregulated insulin signaling contributes to an enhancement of TG accumulation under protein malnutrition. As it is difficult to analyze insulin-induced hepatic TG synthesis in vivo, the isolated hepatocytes derived from rats fed a low-protein diet were used. The hepatocytes were isolated from rats fed a 15% casein diet (15C) as a control diet or a 5% casein diet (5C) as a low-protein diet and then treated with insulin. As shown in vivo, insulin signaling was upregulated in isolated hepatocytes from 5C-fed rats (5C hepatocytes). However, the insulin-induced increase in the mRNA levels of lipogenic enzymes, including acetyl-CoA carboxylase 1 (ACC1) and fatty acid synthase (FAS), was similar in both groups. The amounts of TG synthesized from both glucose and palmitate, as well as ACC1 and FAS protein levels, were increased at the basal state in 5C hepatocytes, but were not further increased by insulin. These results indicate that TG synthesis via both de novo fatty acid synthesis and esterification is enhanced in 5C hepatocytes, which is independent of the upregulation of insulin signaling. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. 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

  13. 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)

  14. Alternative fuels and chemicals from synthesis gas. Quarterly report, April 1--June 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    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. The paper reports the progress on the following tasks: engineering and modifications: AFDU shakedown, operations, deactivation and disposal; and research and development on new processes for DME, chemistry and catalyst development, and oxygenates via synthesis gas.

  15. 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...

  16. ALTERNATIVE FUELS AND CHEMICALS FROM SYNTHESIS GAS. FINAL QUARTERLY STATUS REPORT

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-04-01

    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.

  17. Alternative fuels and chemicals from synthesis gas. Fourth quarterly report, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    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.

  18. Partial oxidation of methane to synthesis gas in a dual catalyst bed system combining irreducible oxide and metallic catalysts

    NARCIS (Netherlands)

    Zhu, J.J.; Mujeebur Rahuman, M.S.M.; van Ommen, J.G.; Lefferts, Leonardus

    2004-01-01

    Operation of partial oxidation of methane to synthesis gas over yttrium-stabilized zirconia (YSZ) at very high temperatures (¿900°C) slightly improves the selectivity to synthesis gas, which is caused by some activity of YSZ for steam and dry reforming of methane. LaCoO3 perovskite is not active in

  19. Effects of Supplementation of Branched-Chain Amino Acids to Reduced-Protein Diet on Skeletal Muscle Protein Synthesis and Degradation in the Fed and Fasted States in a Piglet Model

    OpenAIRE

    Zheng, Liufeng; Wei, Hongkui; He, Pingli; Zhao, Shengjun; Xiang, Quanhang; Pang, Jiaman; Peng, Jian

    2016-01-01

    Supplementation of branched-chain amino acids (BCAA) has been demonstrated to promote skeletal muscle mass gain, but the mechanisms underlying this observation are still unknown. Since the regulation of muscle mass depends on a dynamic equilibrium (fasted losses–fed gains) in protein turnover, the aim of this study was to investigate the effects of BCAA supplementation on muscle protein synthesis and degradation in fed/fasted states and the related mechanisms. Fourteen 26- (Experiment 1) and ...

  20. Design, Synthesis, and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Enrique Iglesia

    2004-09-30

    This project explores the extension of previously discovered Fe-based catalysts with unprecedented Fischer-Tropsch synthesis rate, selectivity, and ability to convert hydrogen-poor synthesis gas streams typical of those produced from coal and biomass sources. Contract negotiations were completed on December 9, 2004. During the first reporting period, we certified a microreactor, installed required analytical equipment, and reproduced synthetic protocols and catalytic performance previously reported. During this second reporting period, we have prepared and tested several Fe-based compositions for Fischer-Tropsch synthesis and tested the effects of product recycle under both subcritical and supercritical conditions. These studies established modest improvements in rates and selectivities with light hydrocarbon recycle without any observed deleterious effects, opening up the opportunities for using of recycle strategies to control temperature profiles in fixed-bed Fe-based Fischer-Tropsch synthesis reactors without any detectable kinetic detriment. In a parallel study, we examined similar effects of recycle for cobalt-based catalysts; marked selectivity improvements were observed as a result of the removal of significant transport restrictions on these catalysts. Finally, we have re-examined some previously unanalyzed data dealing with the mechanism of the Fischer-Tropsch synthesis, specifically kinetic isotope effects on the rate and selectivity of chain growth reactions on Fe-based catalysts.

  1. Effects of Supplementation of Branched-Chain Amino Acids to Reduced-Protein Diet on Skeletal Muscle Protein Synthesis and Degradation in the Fed and Fasted States in a Piglet Model

    Directory of Open Access Journals (Sweden)

    Liufeng Zheng

    2016-12-01

    Full Text Available Supplementation of branched-chain amino acids (BCAA has been demonstrated to promote skeletal muscle mass gain, but the mechanisms underlying this observation are still unknown. Since the regulation of muscle mass depends on a dynamic equilibrium (fasted losses–fed gains in protein turnover, the aim of this study was to investigate the effects of BCAA supplementation on muscle protein synthesis and degradation in fed/fasted states and the related mechanisms. Fourteen 26- (Experiment 1 and 28-day-old (Experiment 2 piglets were fed reduced-protein diets without or with supplemental BCAA. After a four-week acclimation period, skeletal muscle mass and components of anabolic and catabolic signaling in muscle samples after overnight fasting were determined in Experiment 1. Pigs in Experiment 2 were implanted with carotid arterial, jugular venous, femoral arterial and venous catheters, and fed once hourly along with the intravenous infusion of NaH13CO3 for 2 h, followed by a 6-h infusion of [1-13C]leucine. Muscle leucine kinetics were measured using arteriovenous difference technique. The mass of most muscles was increased by BCAA supplementation. During feeding, BCAA supplementation increased leucine uptake, protein synthesis, protein degradation and net transamination. The greater increase in protein synthesis than in protein degradation resulted in elevated protein deposition. Protein synthesis was strongly and positively correlated with the intramuscular net production of α-ketoisocaproate (KIC and protein degradation. Moreover, BCAA supplementation enhanced the fasted-state phosphorylation of protein translation initiation factors and inhibited the protein-degradation signaling of ubiquitin-proteasome and autophagy-lysosome systems. In conclusion, supplementation of BCAA to reduced-protein diet increases fed-state protein synthesis and inhibits fasted-state protein degradation, both of which could contribute to the elevation of skeletal muscle

  2. Effects of Supplementation of Branched-Chain Amino Acids to Reduced-Protein Diet on Skeletal Muscle Protein Synthesis and Degradation in the Fed and Fasted States in a Piglet Model.

    Science.gov (United States)

    Zheng, Liufeng; Wei, Hongkui; He, Pingli; Zhao, Shengjun; Xiang, Quanhang; Pang, Jiaman; Peng, Jian

    2016-12-28

    Supplementation of branched-chain amino acids (BCAA) has been demonstrated to promote skeletal muscle mass gain, but the mechanisms underlying this observation are still unknown. Since the regulation of muscle mass depends on a dynamic equilibrium (fasted losses-fed gains) in protein turnover, the aim of this study was to investigate the effects of BCAA supplementation on muscle protein synthesis and degradation in fed/fasted states and the related mechanisms. Fourteen 26- (Experiment 1) and 28-day-old (Experiment 2) piglets were fed reduced-protein diets without or with supplemental BCAA. After a four-week acclimation period, skeletal muscle mass and components of anabolic and catabolic signaling in muscle samples after overnight fasting were determined in Experiment 1. Pigs in Experiment 2 were implanted with carotid arterial, jugular venous, femoral arterial and venous catheters, and fed once hourly along with the intravenous infusion of NaH 13 CO₃ for 2 h, followed by a 6-h infusion of [1- 13 C]leucine. Muscle leucine kinetics were measured using arteriovenous difference technique. The mass of most muscles was increased by BCAA supplementation. During feeding, BCAA supplementation increased leucine uptake, protein synthesis, protein degradation and net transamination. The greater increase in protein synthesis than in protein degradation resulted in elevated protein deposition. Protein synthesis was strongly and positively correlated with the intramuscular net production of α-ketoisocaproate (KIC) and protein degradation. Moreover, BCAA supplementation enhanced the fasted-state phosphorylation of protein translation initiation factors and inhibited the protein-degradation signaling of ubiquitin-proteasome and autophagy-lysosome systems. In conclusion, supplementation of BCAA to reduced-protein diet increases fed-state protein synthesis and inhibits fasted-state protein degradation, both of which could contribute to the elevation of skeletal muscle mass in

  3. 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,

  4. 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

  5. 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.

  6. 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....

  7. Dual catalyst bed concept for catalytic partial oxidation of methane to synthesis gas

    NARCIS (Netherlands)

    Zhu, J.J.; Mujeebur Rahuman, M.S.M.; van Ommen, J.G.; Lefferts, Leonardus

    2004-01-01

    A system with two catalyst beds instead of one single metal catalyst bed is proposed for catalytic partial oxidation of methane (CPOM) to synthesis gas. In this dual catalyst bed system, an irreducible stable oxide, such as yttrium-stabilized zirconia (YSZ), is used in the first catalyst bed to

  8. Iron Particle Size Effects for Direct Production of Lower Olefins from Synthesis Gas

    NARCIS (Netherlands)

    Torres Galvis, H.M.|info:eu-repo/dai/nl/314116249; Bitter, J.H.|info:eu-repo/dai/nl/160581435; Davidian, T.; Ruitenbeek, M.; Dugulan, A.I.; de Jong, K.P.|info:eu-repo/dai/nl/06885580X

    2012-01-01

    The Fischer–Tropsch synthesis of lower olefins (FTO) is an alternative process for the production of key chemical building blocks from non-petroleum-based sources such as natural gas, coal, or biomass. The influence of the iron carbide particle size of promoted and unpromoted carbon nanofiber

  9. 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, ...

  10. Reactive gas condensation synthesis of aluminum nitride nanoparticles.

    Science.gov (United States)

    Baker, Colin C; Ceylan, Abdullah; Shah, S Ismat

    2006-01-01

    Aluminum Nitride (AIN) nanoparticles were synthesized using a Reactive Gas Condensation (RGC) technique in which a mixture of ammonia (NH3) and nitrogen (N2) gases were used for the nitridation of aluminum. NH3 served as the reactive gas, while N2 served as both a carrier gas and the inert source for particle condensation. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses revealed that at reactive gas compositions greater than 10% NH3 in N2, samples were composed entirely of hexagonal AIN nanoparticles. Electron diffraction patterns showed single crystal hexagonal AIN structure. The particle size was controlled by varying the pressure of the gas mixture. AIN nanoparticles were dispersed in a liquid matrix to enhance thermal conductivity. Results showed that a minimal addition of AIN increased the thermal conductivity of hydrocarbon pump oil by approximately 27%. The thermal conductivity became constant after reaching a maximum above 0.01 wt% AIN. Temporal stability of AIN was studied by XRD. Samples exposed to air for extended periods of time and analyzed by XRD show no degradation of crystalline AIN nanoparticles.

  11. Synthesis gas regeneration electrotechnology using volume high-voltage pulsed discharges: corona and barrier ones

    Directory of Open Access Journals (Sweden)

    M.I. Boyko

    2014-09-01

    Full Text Available Factory testing of a created high-voltage complex (plant has been conducted. The complex consists of two pulse generators with the repetition rate of up to 50,000 pulses per second and load reactors with pulsed discharges - corona and barrier ones. Transistor (IGBT keys are used as energy switches. The efficient mode of coke gas methane conversion (steam reforming to syngas has been obtained with application of the complex created. A unidirectional action of the pulsed discharges, the gas mixture temperature, and a nickel catalyst has reduced the specific energy consumption for synthesis gas regeneration during the conversion. A feasible mechanism of this conversion is described.

  12. Effect of chlorpromazine on lipid metabolism in aortas from cholesterol-fed rabbits and normal rats, in vitro: inhibition of sterol esterification and modification of phospholipid synthesis

    International Nuclear Information System (INIS)

    Bell, F.P.

    1983-01-01

    Chlorpromazine (CPZ), a major tranquilizer, was found to be a potent inhibitor of acylCoA:cholesterol acyltransferase (ACAT, EC 2.3.1.26) in isolated arterial microsomes and in intact arterial tissue from the rat and cholesterol-fed rabbit in vitro. In isolated rabbit arterial microsomes, CPZ resulted in a concentration-dependent inhibition of ACAT with 50% inhibition of [1-14C]oleoylCoA incorporation into [14C]cholesteryl esters occurring at 0.1 mM CPZ. CPZ also effectively inhibited the incorporation of [14C]oleate into triglycerides without affecting incorporation into diglycerides. Additionally, CPZ altered the pattern of arterial phospholipids synthesized from [1-14C]oleate. Incorporation into phosphatidylcholine was depressed while incorporation into phosphatidylinositol was increased. Since diglyceride synthesis appeared to be unaffected by CPZ, a redirection of phosphatidic acid into the CDP-diglyceride pathway of glycerolipid synthesis does not adequately account for the effect of CPZ on arterial phospholipid and triglyceride synthesis in these experiments

  13. Effect of inclusion of different levels of silage on rumen microbial population and microbial protein synthesis in dairy steers fed on rice straw

    Directory of Open Access Journals (Sweden)

    Thien Truong Giang Nguyen

    2017-02-01

    Full Text Available Objective Leucaena leucocephala (Leucaena is a perennial tropical legume that can be directly grazed or harvested and offered to ruminants as hay, silage, or fresh. However, Leucaena contain phenolic compounds, which are considered anti-nutritional factors as these may reduce intake, digestibility and thus animal performance. Therefore, the objective of this experiment was to determine effects of Leucaena silage (LS feeding levels on rumen microbial populations, N-balance and microbial protein synthesis in dairy steers. Methods Four, rumen fistulated dairy steers with initial weight of 167±12 kg were randomly assigned to receive dietary treatments according to a 4×4 Latin square design. Treatments were as followings: T1 = untreated rice straw (RS; Control, T2 = 70% RS+30% LS, T3 = 40% RS+60% LS, and T4 = 100% LS. Dairy steers were fed rice straw and LS ad libitum and supplemented with concentrate at 0.2% of body weight/d. Results Results revealed that the rumen microbial population, especially cellulolytic, proteolytic bacteria and fungal zoospores were enhanced in steers that received 60% of LS (p0.05. Protozoal population was linearly decreased with increasing level of LS (p<0.05. Moreover, N-balance and microbial protein synthesis were enhanced by LS feeding (p<0.05 and were the highest in 60% LS group. Conclusion Based on this study, it could be concluded that replacement of RS with 60% LS significantly improved microbial population and microbial protein synthesis in diary steers.

  14. Oxygen transport membrane based advanced power cycle with low pressure synthesis gas slip stream

    Science.gov (United States)

    Kromer, Brian R.; Litwin, Michael M.; Kelly, Sean M.

    2016-09-27

    A method and system for generating electrical power in which a high pressure synthesis gas stream generated in a gasifier is partially oxidized in an oxygen transport membrane based reactor, expanded and thereafter, is combusted in an oxygen transport membrane based boiler. A low pressure synthesis gas slip stream is split off downstream of the expanders and used as the source of fuel in the oxygen transport membrane based partial oxidation reactors to allow the oxygen transport membrane to operate at low fuel pressures with high fuel utilization. The combustion within the boiler generates heat to raise steam to in turn generate electricity by a generator coupled to a steam turbine. The resultant flue gas can be purified to produce a carbon dioxide product.

  15. Design, Synthesis, and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Akio Ishikawa; Manuel Ojeda; Nan Yao; Enrique Iglesia

    2006-03-31

    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{sub 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{sub 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

  16. DESIGN, SYNTHESIS, AND MECHANISTIC EVALUATION OF IRON-BASED CATALYSIS FOR SYNTHESIS GAS CONVERSION TO FUELS AND CHEMICALS

    Energy Technology Data Exchange (ETDEWEB)

    Akio Ishikawa; Manuel Ojeda; Enrique Iglesia

    2005-03-31

    This project explores the extension of previously discovered Fe-based catalysts to hydrogen-poor synthesis gas streams derived from coal and biomass sources. These catalysts have previously shown unprecedented Fischer-Tropsch synthesis rate, selectivity with synthesis gas derived from methane. During the first reporting period, we certified a microreactor, installed required analytical equipment, and reproduced synthetic protocols and catalytic performance 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 this third reporting period, we have prepared a large number of Fe-based catalyst compositions using precipitation and impregnations methods with both supercritical and subcritical drying and with the systematic use of surface active agents to prevent pore collapse during drying steps required in synthetic protocols. These samples were characterized during this period using X-ray diffraction, surface area, and temperature-programmed reduction measurements. These studies have shown that these synthesis methods lead to even higher surface areas than in our previous studies and confirm the crystalline structures of these materials and their reactivity in both oxide-carbide interconversions and in Fischer-Tropsch synthesis catalysis. Fischer-Tropsch synthesis reaction rates and selectivities with low H{sub 2}/CO ratio feeds (H{sub 2}/CO = 1) were the highest reported in the literature at the low-temperature and relatively low pressure in our measurements. Current studies are exploring the optimization of the sequence of impregnation of Cu, K, and Ru promoters, of the activation and reaction conditions, and of the co-addition of light hydrocarbons to increase diffusion rates of primary olefin products so as to increase the selectivity to unsaturated products. Finally, we are also addressing

  17. In vitro gas and methane production in rumen fluid from dairy cows fed grass silages differing in plant maturity, compared to in vivo data.

    Science.gov (United States)

    Macome, F M; Pellikaan, W F; Hendriks, W H; Warner, D; Schonewille, J T; Cone, J W

    2018-04-14

    The relationship between in vitro rumen CH 4 production of grass silages, using the gas production technique, and in vivo data obtained with the same cows and rations in respiration chambers was investigated. Silages were made from grass harvested in 2013 on May 6th, May 25th, July 1st and July 8th. The grass silages were used to formulate four different rations which were fed to 24 cows in early and late lactation, resulting in a slightly different dry matter intake (DMI; 16.5 kg/day vs. 15.4 kg/day). The experimental rations consisted of 70% grass silage, 10% maize silage, and 20% concentrates on a dry matter basis. Cows were adapted to the rations for 17 days before rumen fluid was collected via oesophageal tubing, and in vitro gas and CH 4 production were analysed. In vitro total gas and CH 4 production of the (ensiled) grass expressed as ml/g OM decreased with advancing maturity of the grass. The in vitro CH 4 production after 48 hr of incubation expressed in ml/g OM did not correlate with the in vivo CH 4 production expressed in g/kg organic matter intake or g/kg DMI (R 2  = .00-.18, p ≥ .287). The differences in CH 4 emission per unit of intake observed in vivo were rather small between the different rations, which also contributed to the observed poor relationship. Utilizing stepwise multiple regression improved the correlation only slightly. In vitro gas and CH 4 production varied based on whether donor cows were previously adapted to the respective ration or not, suggesting that careful adaption to the experimental diet should be envisaged in in vitro gas and CH 4 production experiments. © 2018 The Authors. Journal of Animal Physiology and Animal Nutrition Published by Blackwell Verlag GmbH.

  18. Recent developments and benefits of high-speed PWM inverter-fed induction-motor drive for gas filtration in nuclear power plants

    International Nuclear Information System (INIS)

    Mhango, L.M.C.; Rennie, J.A.

    1993-01-01

    This paper will discuss new developments relating to the use of a high-speed inverter-fed induction-motor drive for gas filtration of the main gas circulator compartment in nuclear power stations. Conventional drives use low speed induction motors which operate from fixed supply frequencies of either 50 Hz or 60 Hz. Operating speeds are essentially constant and for a 2-pole, 50 Hz machine the speed is 2750 r/min approximately. Due to the low operating speed, the sizes of both the motor and the impeller are rather large. For this type of drive, fixed speed operation results in high capital and operational costs. The system environmental conditions of very dry helium are severe and the operating temperature and pressure are both high for this type of motor. The expected system life is 40 years approximately and does not allow maintenance. In operation the motor is fully submerged in the process gas. This contribution will present some of the results of a development program carried out by two Howden Group companies on a high-speed drive. (Author)

  19. 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.

  20. Coating synthesis on dielectric substrates assisted by pulsed beams of high-energy gas atoms

    Science.gov (United States)

    Grigoriev, S. N.; Melnik, Yu A.; Metel, A. S.

    2017-05-01

    Titanium nitride and aluminum nitride coatings have been deposited on glass and aluminum oxide substrates in a flow of metal atoms accompanied by high-energy gas atoms. The metal atoms are produced due to sputtering of a flat rectangular magnetron target. The gas atoms with energy up to 25 keV are produced due to charge exchange collisions of ions extracted from the magnetron discharge plasma and accelerated by high-voltage pulses applied to a flat grid parallel to the target. The metal atoms pass through the grid and deposit on the substrate. Conjunction of their trajectories with those of gas atoms bombarding the growing coating enables the coating synthesis on complex-shape dielectric products planetary rotating inside the vacuum chamber. Mixing high-energy gas atoms of the coating and substrate atoms substantially improves the coating adhesion.

  1. 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.

  2. 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.)

  3. 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.

  4. 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.

  5. 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.

  6. Wet Chemical Synthesis and Screening of Thick Porous Oxide Films for Resistive Gas Sensing Applications

    Directory of Open Access Journals (Sweden)

    Wilhelm F. Maier

    2006-11-01

    Full Text Available A method of wet chemical synthesis suitable for high throughput and combinatorial applications has been developed for the synthesis of porous resistive thick-film gas sensors. This method is based on the robot-controlled application of unstable metal oxide suspensions on an array of 64 inter-digital electrodes positioned on an Al2O3 substrate. SnO2, WO3, ZrO2, TiO2, CeO2, In2O3 and Bi2O3 were chosen as base oxides, and were optimised by doping or mixed oxide formation. The parallel synthesis of mixed oxide sensors is illustrated by representative examples. The electrical characteristics and the sensor performance of the films were measured by high-throughput impedance spectroscopy while supplying various test gases (H2, CO, NO, NO2, propene. Data collection, data mining techniques applied and the best potential sensor materials discovered are presented.

  7. Design, Synthesis, and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Akio; Ishikawa; Manuel Ojeda; Nan Yao; Enrique Iglesia

    2006-09-30

    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 rates and selectivities 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{sub 5+}, olefins). During the fifth reporting period, we studied the effects of different promoters on catalytic performance, specifically how their sequence of addition dramatically influenced the performance of these materials in the Fischer-Tropsch synthesis. We also continued our studies of the kinetic behavior of these materials. Specifically, the effects of H{sub 2}, CO, and CO{sub 2} on the rates and selectivities of Fischer-Tropsch Synthesis reactions led us to propose a new sequence of elementary steps on Fe and Co Fischer-Tropsch catalysts. More specifically, we were focused on the roles of hydrogen-assisted and alkali-assisted dissociation of CO in determining rates and CO{sub 2} selectivities. During this sixth reporting period, we have studied the validity of the mechanism that we propose by analyzing the H{sub 2}/D{sub 2} kinetic isotope effect (r{sub H}/r{sub D}) over a conventional iron-based Fischer-Tropsch catalyst Fe-Zn-K-Cu. We have observed experimentally that

  8. Design, Synthesis and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Akio Ishikawa; Manuel Ojeda; Nan Yao; Enrique Iglesia

    2007-03-31

    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 rates and selectivities for 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 materials 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{sub 5+}, olefins). During the fifth and sixth reporting period, we studied the effects of different promoters on catalytic performance, specifically how their sequence of addition dramatically influenced the performance of these materials in the Fischer-Tropsch synthesis. We also continued our studies of the kinetic behavior of these materials during the sixth reporting period. Specifically, the effects of H{sub 2}, CO, and CO{sub 2} on the rates and selectivities of Fischer-Tropsch Synthesis reactions led us to propose a new sequence of elementary steps on Fe and Co Fischer-Tropsch catalysts. Finally, we also started a study of the use of colloidal precipitation methods for the synthesis small Co clusters using recently developed methods to explore possible further improvements in FTS rates and selectivities. We found that colloidal synthesis makes possible the preparation of small cobalt particles, although large amount of cobalt silicate species, which are difficult to reduce, were formed. During this

  9. Design, Synthesis, and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Akio Ishikawa; Manuel Ojeda; Enrique Iglesia

    2005-09-30

    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 reporting period, 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{sub 5+}, olefins). During this fourth reporting period, we have determined the effects of different promoters on catalytic performance. More specifically, we have found that the sequence in which promoters are introduced has a marked positive impact on rates and selectivities. Cu or Ru chemical promoters should be impregnated before K to achieve higher Fischer-Tropsch synthesis rates. The catalyst prepared in this way was evaluated for 240 h, showing a high catalytic activity and stability after an initial period of time necessary for the formation of the active phases. Concurrently, we are studying optimal activation procedures, which involve the reduction and carburization of oxide precursors during the early stages of contact with synthesis gas. Activation at low temperatures (523 K), made possible by optimal introduction of Cu or Ru, leads to lower catalyst surface area than higher activation temperatures, but to higher reaction rates, because such low temperatures avoid concurrent deactivation

  10. Trans fatty acids: chemical synthesis of eicosapentaenoic acid isomers and detection in rats fed a deodorized fish oil diet.

    Science.gov (United States)

    Ferreri, Carla; Grabovskiy, Stanislav A; Aoun, Manar; Melchiorre, Michele; Kabal'nova, Natalia; Feillet-Coudray, Christine; Fouret, Gilles; Coudray, Charles; Chatgilialoglu, Chryssostomos

    2012-03-19

    Eicosapentaenoic acid (EPA) is a polyunsaturated fatty acid present in fish oils used for omega-3 enriched diets. The natural cis double bond geometry can be transformed to the trans configuration during the deodorization process utilized in the food industry. The analytical discrimination of the possible five monotrans regioisomers represents a limiting step for the recognition and structure-activity relationship in connection with the harmful effects of trans fatty acids in health. We carried out a dual synthetic strategy, providing new access to monotrans EPA isomers and valuable information on GC and NMR characteristics for further applications in metabolomics and lipidomics. This small library was used as an analytical reference for isomer determination in deodorized fish oils and the follow-up of rats fed fish oil diets, evidencing for the first time that monotrans EPA isomers are incorporated in liver mitochondrial membranes after dietary intake. © 2012 American Chemical Society

  11. Nitrogen and energy balance in growing mink (Mustela vison) fed different levels of bacterial protein meal produced with natural gas

    DEFF Research Database (Denmark)

    Hellwing, Anne Louise Frydendahl; Tauson, Anne-Helene; Ahlstrøm, Øystein

    2005-01-01

    % (Diet IV) of the digested nitrogen (DN) was replaced with BPM. Nitrogen balance and respiration experiments (indirect calorimetry) were carried out when the animals were approximately 9.5, 14.5, 17.5, 23.5 and 28.5 weeks of age. The apparent digestibility of crude protein and energy decreased......The objective of this study was to estimate the effect of increasing the dietary content of bacterial protein meal (BPM) on energy and protein metabolism in growing mink kits. Sixteen male mink kits of the standard brown genotype were randomly fed one of four diets: A control (Diet III) and 60...... significantly with increasing dietary BPM. The retained nitrogen was 0.45, 0.54, 0.52 and 0.40 g/kg0,75 on Diets I, II, III and IV, respectively, the observed differences between diets being non-significant (p=0.06). Heat production (HE) was between 645 and 665 kJ/kg0.75 on all diets (p=0.78). retained energy...

  12. 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)

  13. 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.

  14. Dietary n-3 long-chain polyunsaturated fatty acids modify phosphoenolpyruvate carboxykinase activity and lipid synthesis from glucose in adipose tissue of rats fed a high-sucrose diet.

    Science.gov (United States)

    Londero, Lisiane G; Rieger, Débora K; Hansen, Fernanda; Silveira, Simone L; Martins, Tiago L; Lulhier, Francisco; da Silva, Roselis S; Souza, Diogo O; Perry, Marcos L S; de Assis, Adriano M

    2013-12-01

    Long-chain polyunsaturated n-3 fatty acids (n-3 LCPUFAs) have hypolipidemic effects and modulate intermediary metabolism to prevent or reverse insulin resistance in a way that is not completely elucidated. Here, effects of these fatty acids on the lipid profile, phosphoenolpyruvate carboxykinase (PEPCK) activity, lipid synthesis from glucose in epididymal adipose tissue (Ep-AT) and liver were investigated. Male rats were fed a high-sucrose diet (SU diet), containing either sunflower oil or a mixture of sunflower and fish oil (SU-FO diet), and the control group was fed a standard diet. After 13 weeks, liver, adipose tissue and blood were harvested and analysed. The dietary n-3 LCPUFAs prevented sucrose-induced increase in adiposity and serum free fat acids, serum and hepatic triacylglycerol and insulin levels. Furthermore, these n-3 LCPUFAs decreased lipid synthesis from glucose and increased PEPCK activity in the Ep-AT of rats fed the SU-FO diet compared to those fed the SU diet, besides reducing lipid synthesis from glucose in hepatic tissue. Thus, the inclusion of n-3 LCPUFAs in the diet may be beneficial for the prevention or attenuation of dyslipidemia and insulin resistance, and for reducing the risk of related chronic diseases. Copyright © 2013 John Wiley & Sons, Ltd.

  15. In-situ study of the gas-phase composition and temperature of an intermediate-temperature solid oxide fuel cell anode surface fed by reformate natural gas

    Science.gov (United States)

    Santoni, F.; Silva Mosqueda, D. M.; Pumiglia, D.; Viceconti, E.; Conti, B.; Boigues Muñoz, C.; Bosio, B.; Ulgiati, S.; McPhail, S. J.

    2017-12-01

    An innovative experimental setup is used for in-depth and in-operando characterization of solid oxide fuel cell anodic processes. This work focuses on the heterogeneous reactions taking place on a 121 cm2 anode-supported cell (ASC) running with a H2, CH4, CO2, CO and steam gas mixture as a fuel, using an operating temperature of 923 K. The results have been obtained by analyzing the gas composition and temperature profiles along the anode surface in different conditions: open circuit voltage (OCV) and under two different current densities, 165 mA cm-2 and 330 mA cm-2, corresponding to 27% and 54% of fuel utilization, respectively. The gas composition and temperature analysis results are consistent, allowing to monitor the evolution of the principal chemical and electrochemical reactions along the anode surface. A possible competition between CO2 and H2O in methane internal reforming is shown under OCV condition and low current density values, leading to two different types of methane reforming: Steam Reforming and Dry Reforming. Under a current load of 40 A, the dominance of exothermic reactions leads to a more marked increase of temperature in the portion of the cell close to the inlet revealing that current density is not uniform along the anode surface.

  16. Aluminum-doped ZnO nanoparticles: gas-phase synthesis and dopant location

    Science.gov (United States)

    Schilling, Carolin; Zähres, Manfred; Mayer, Christian; Winterer, Markus

    2014-07-01

    Aluminum-doped ZnO (AZO) nanoparticles are studied widely as transparent conducting alternatives for indium tin oxide. However, the properties of AZO vary in different investigations not only with the amount of dopant and the particle size, but also with other parameters such as synthesis method and conditions. Hence, AZO nanoparticles, synthesized in the gas phase, were investigated to study the influence of the synthesis parameters dopant level, reactor temperature and residence time in the reaction zone on the particle characteristics. The local structure of the dopant in semiconductors determines whether the doping is functional, i.e., whether mobile charge carriers are generated. Therefore, information obtained from 27Al solid-state NMR spectroscopy, X-ray diffraction, photoluminescence and UV-Vis spectroscopy was used to understand how the local structure influences particles characteristics and how the local structure itself can be influenced by the synthesis parameters. In addition to AZO particles of different Al content, pure ZnO, Al2O3, ZnAl2O4 and core-shell particles of ZnO and Al2O3 were synthesized for comparison and aid to a deeper understanding of the formation of AZO nanoparticles in the gas phase.

  17. Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

    Energy Technology Data Exchange (ETDEWEB)

    Marina, Olga A.; Coyle, Christopher A.; Edwards, Danny J.; Chou, Yeong-Shyung; Cramer, Carolyn N. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Pederson, Larry R. [North Dakota State University, Fargo, ND 58102 (United States)

    2011-01-15

    Oxidation-resistant alloys find use as interconnect materials, heat exchangers, and gas supply tubing in solid oxide fuel cell (SOFC) systems, especially when operated at temperatures below {proportional_to}800 C. If fueled with synthesis gas derived from coal or biomass, such metallic components could be exposed to impurities contained in those fuel sources. In this study, coupons of ferritic stainless steels Crofer 22 APU and SS 441, austenitic nickel-chromium superalloy Inconel 600, and an alumina-forming high nickel alloy alumel were exposed to synthesis gas containing {<=}2 ppm phosphorus, arsenic and antimony, and reaction products were tested. Crofer 22 APU coupons coated with a (Mn,Co){sub 3}O{sub 4} protective layer were also evaluated. Phosphorus was found to be the most reactive. On Crofer 22 APU, the (Mn,Cr){sub 3}O{sub 4} passivation layer reacted to form an Mn-P-O product, predicted to be manganese phosphate from thermochemical calculations, and Cr{sub 2}O{sub 3}. On SS 441, reaction of phosphorus with (Mn,Cr){sub 3}O{sub 4} led to the formation of manganese phosphate as well as an Fe-P product, predicted from thermochemical calculations to be Fe{sub 3}P. Minimal interactions with antimony or arsenic in synthesis gas were limited to Fe-Sb and Fe-As solid solution formation. Though not intended for use on the anode side, a (Mn,Co){sub 3}O{sub 4} spinel coating on Crofer 22 APU reacted with phosphorus in synthesis gas to produce products consistent with Mn{sub 3}(PO{sub 4}){sub 2} and Co{sub 2}P. A thin Cr{sub 2}O{sub 3} passivation layer on Inconel 600 did not prevent the formation of nickel phosphides and arsenides and of iron phosphides and arsenides, though no reaction with Cr{sub 2}O{sub 3} was apparent. On alumel, an Al{sub 2}O{sub 3} passivation layer rich in Ni did not prevent the formation of nickel phosphides, arsenides, and antimonides, though no reaction with Al{sub 2}O{sub 3} occurred. This work shows that unprotected metallic components of

  18. Evaluation and Selection of Bacillus Species Based on Enzyme Production, Antimicrobial Activity, and Biofilm Synthesis as Direct-Fed Microbial Candidates for Poultry

    Science.gov (United States)

    Latorre, Juan D.; Hernandez-Velasco, Xochitl; Wolfenden, Ross E.; Vicente, Jose L.; Wolfenden, Amanda D.; Menconi, Anita; Bielke, Lisa R.; Hargis, Billy M.; Tellez, Guillermo

    2016-01-01

    Social concern about misuse of antibiotics as growth promoters (AGP) and generation of multidrug-resistant bacteria have restricted the dietary inclusion of antibiotics in livestock feed in several countries. Direct-fed microbials (DFM) are one of the multiple alternatives commonly evaluated as substitutes of AGP. Sporeformer bacteria from the genus Bacillus have been extensively investigated because of their extraordinary properties to form highly resistant endospores, produce antimicrobial compounds, and synthesize different exogenous enzymes. The purpose of the present study was to evaluate and select Bacillus spp. from environmental and poultry sources as DFM candidates, considering their enzyme production profile, biofilm synthesis capacity, and pathogen-inhibition activity. Thirty-one Bacillus isolates were screened for in vitro relative enzyme activity of amylase, protease, lipase, and phytase using a selective media for each enzyme, with 3/31 strains selected as superior enzyme producers. These three isolates were identified as Bacillus subtilis (1/3), and Bacillus amyloliquefaciens (2/3), based on biochemical tests and 16S rRNA sequence analysis. For evaluation of biofilm synthesis, the generation of an adherent crystal violet-stained ring was determined in polypropylene tubes, resulting in 11/31 strains showing a strong biofilm formation. Moreover, all Bacillus strains were evaluated for growth inhibition activity against Salmonella enterica serovar Enteritidis (26/31), Escherichia coli (28/31), and Clostridioides difficile (29/31). Additionally, in previous in vitro and in vivo studies, these selected Bacillus strains have shown to be resistant to different biochemical conditions of the gastrointestinal tract of poultry. Results of the present study suggest that the selection and consumption of Bacillus-DFM, producing a variable set of enzymes and antimicrobial compounds, may contribute to enhanced performance through improving nutrient digestibility

  19. Evaluation and selection of Bacillus species based on enzyme production, antimicrobial activity and biofilm synthesis as direct-fed microbials candidates for poultry

    Directory of Open Access Journals (Sweden)

    Juan D Latorre

    2016-10-01

    Full Text Available Social concern about misuse of antibiotics as growth promoters (AGP and generation of multidrug-resistant bacteria have restricted the dietary inclusion of antibiotics in livestock feed in several countries. Direct-fed microbials (DFM are one of the multiple alternatives commonly evaluated as substitutes of AGP. Sporeformer bacteria from the genus Bacillus have been extensively investigated because of their extraordinary properties to form highly-resistant endospores, production of antimicrobial compounds and synthesize different exogenous enzymes. The purpose of the present study was to evaluate and select Bacillus spp. from environmental and poultry sources as DFM candidates, considering their enzyme production profile, biofilm synthesis capacity and pathogen-inhibition activity. Thirty one Bacillus isolates were screened for in vitro relative enzyme activity of amylase, protease, lipase and phytase using a selective media for each enzyme, with 3/31 strains selected as superior enzyme producers. These three isolates were identified as B. subtilis (1/3, and B. amyloliquefaciens (2/3 based on biochemical tests and 16S rRNA sequence analysis. For evaluation of biofilm synthesis, the generation of an adherent crystal violet-stained ring was determined in polypropylene tubes, resulting in 11/31 strains showing a strong biofilm formation. Moreover, all Bacillus strains were evaluated for growth inhibition activity against Salmonella enterica serovar Enteritidis (26/31, Escherichia coli (28/31 and Clostridioides difficile (29/31. Additionally, in previous in vitro and in vivo studies, these selected Bacillus strains have shown to be resistant to different biochemical conditions of the gastrointestinal tract of poultry. Results of the present study suggest that the selection and consumption of Bacillus-DFM, producing a variable set of enzymes and antimicrobial compounds may contribute to enhanced performance through improving nutrient digestibility

  20. Promoted Iron Nanocrystals Obtained via Ligand Exchange as Active and Selective Catalysts for Synthesis Gas Conversion.

    Science.gov (United States)

    Casavola, Marianna; Xie, Jingxiu; Meeldijk, Johannes D; Krans, Nynke A; Goryachev, Andrey; Hofmann, Jan P; Dugulan, A Iulian; de Jong, Krijn P

    2017-08-04

    Colloidal synthesis routes have been recently used to fabricate heterogeneous catalysts with more controllable and homogeneous properties. Herein a method was developed to modify the surface composition of colloidal nanocrystal catalysts and to purposely introduce specific atoms via ligands and change the catalyst reactivity. Organic ligands adsorbed on the surface of iron oxide catalysts were exchanged with inorganic species such as Na 2 S, not only to provide an active surface but also to introduce controlled amounts of Na and S acting as promoters for the catalytic process. The catalyst composition was optimized for the Fischer-Tropsch direct conversion of synthesis gas into lower olefins. At industrially relevant conditions, these nanocrystal-based catalysts with controlled composition were more active, selective, and stable than catalysts with similar composition but synthesized using conventional methods, possibly due to their homogeneity of properties and synergic interaction of iron and promoters.

  1. Liquid phase low temperature method for production of methanol from synthesis gas and catalyst formulations therefor

    Science.gov (United States)

    Mahajan, Devinder

    2005-07-26

    The invention provides a homogenous catalyst for the production of methanol from purified synthesis gas at low temperature and low pressure which includes a transition metal capable of forming transition metal complexes with coordinating ligands and an alkoxide, the catalyst dissolved in a methanol solvent system, provided the transition metal complex is not transition metal carbonyl. The coordinating ligands can be selected from the group consisting of N-donor ligands, P-donor ligands, O-donor ligands, C-donor ligands, halogens and mixtures thereof.

  2. Clinical, blood gas and biochemical profile of diarrheic dairy calves fed starter concentrate containing citrus pulp as a replacement for corn

    Directory of Open Access Journals (Sweden)

    Marcelo Cezar Soares

    Full Text Available ABSTRACT: The objective of this study was to evaluate clinical signs, gas analysis, and metabolic effects of diarrhea in milk-fed calves consuming starter feed containing citrus pulp (CP as a replacement for corn. Twenty-four newborn Holstein male calves were distributed into treatments according to starter composition: (1 0% CP, (2 32% CP, (3 64% CP, on dry matter basis. The calves were housed in individual hutches, with free access to water and concentrate, and received 4 L/d of milk replacer. After diarrhea diagnosis, evaluations of fecal score, score of clinical signs and measurement of physiological parameters were performed three times a day during 3-d. Blood samples were collected for electrolytes, blood gases, and plasma biochemical analysis. Starter feed composition had no negative effect (P>0.05 on fecal score, characteristics of diarrheic stools and on the aggravation of diarrhea clinical signs. Biochemical, blood gases and electrolytes changes, as a function of starter composition, did not resulted (P>0.05 in dehydration, acidosis, or other metabolic disturbance animals. Total lactate and D-lactate plasma concentrations were higher for calves on control and 64% CP, and L-lactate was highest for the 64% CP; however, calves showed no signs of metabolic acidosis. Thermal comfort indexes influenced clinical and physiological parameters (P<0.05. Citrus pulp may replace corn in starter composition without prejudice to intestinal health or metabolism of young diarrheic calves.

  3. Synthesis methods, microscopy characterization and device integration of nanoscale metal oxide semiconductors for gas sensing.

    Science.gov (United States)

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

    2009-01-01

    A comparison is made between SnO(2), ZnO, and TiO(2) single-crystal nanowires and SnO(2) 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 H(2), 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 activation energies for the catalyst-assisted systems.

  4. 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%.

  5. 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)

  6. 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)

  7. 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.

  8. 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.

  9. 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.

  10. 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)

  11. Methanol production from steel-work off-gases and biomass based synthesis gas

    International Nuclear Information System (INIS)

    Lundgren, J.; Ekbom, T.; Hulteberg, C.; Larsson, M.; Grip, C.-E.; Nilsson, L.; Tunå, P.

    2013-01-01

    Highlights: • The integration of a methanol synthesis process in steel plants increases the gas utilization efficiency. • Methanol produced by off-gases from steelmaking combined with biomass show competitive production costs versus petrol. • The integration of a methanol synthesis process in steel plants may reduce the specific CO 2 -emissions of the plant. - Abstract: Off-gases generated during steelmaking are to a large extent used as fuels in process units within the plant. The surplus gases are commonly supplied to a plant for combined heat and power production. The main objective of this study has been to techno-economically investigate the feasibility of an innovative way of producing methanol from these off-gases, thereby upgrading the economic value of the gases. Cases analyzed have included both off-gases only and mixes with synthesis gas, based on 300 MW th of biomass. The SSAB steel plant in the town of Luleå, Sweden has been used as a basis. The studied biomass gasification technology is based on a fluidized-bed gasification technology, where the production capacity is determined from case to case coupled to the heat production required to satisfy the local district heating demand. Critical factors are the integration of the gases with availability to the synthesis unit, to balance the steam system of the biorefinery and to meet the district heat demand of Luleå. The annual production potential of methanol, the overall energy efficiency, the methanol production cost and the environmental effect have been assessed for each case. Depending on case, in the range of 102,000–287,000 ton of methanol can be produced per year at production costs in the range of 0.80–1.1 EUR per liter petrol equivalent at assumed conditions. The overall energy efficiency of the plant increases in all the cases, up to nearly 14%-units on an annual average, due to a more effective utilization of the off-gases. The main conclusion is that integrating methanol

  12. On-line gas chromatographic analysis of higher alcohol synthesis products from syngas.

    Science.gov (United States)

    Andersson, Robert; Boutonnet, Magali; Järås, Sven

    2012-07-20

    An on-line gas chromatographic (GC) system has been developed for rapid and accurate product analysis in catalytic conversion of syngas (a mixture of H₂ and CO) to alcohols, so called "higher alcohol synthesis (HAS)". Conversion of syngas to higher alcohols is an interesting second step in the route of converting coal, natural gas and possibly biomass to liquid alcohol fuel and chemicals. The presented GC system and method are developed for analysis of the products formed from syngas using alkali promoted MoS₂ catalysts, however it is not limited to these types of catalysts. During higher alcohol synthesis not only the wanted short alcohols (∼C₂-C₅) are produced, but also a great number of other products in smaller or greater amounts, they are mainly short hydrocarbons (olefins, paraffins, branched, non-branched), aldehydes, esters and ketones as well as CO₂, H₂O. Trace amounts of sulfur-containing compounds can also be found in the product effluent when sulfur-containing catalysts are used and/or sulfur-containing syngas is feed. In the presented GC system, most of them can be separated and analyzed within 60 min without the use of cryogenic cooling. Previously, product analysis in "higher alcohol synthesis" has in most cases been carried out partly on-line and partly off-line, where the light gases (gases at room temp) are analyzed on-line and liquid products (liquid at room temp) are collected in a trap for later analysis off-line. This method suffers from many drawbacks compared to a complete on-line GC system. In this paper an on-line system using an Agilent 7890 gas chromatograph equipped with two flame ionization detectors (FID) and a thermal conductivity detector (TCD), together with an Agilent 6890 with sulfur chemiluminescence dual plasma detector (SCD) is presented. A two-dimensional GC system with Deans switch (heart-cut) and two capillary columns (HP-FFAP and HP-Al₂O₃) was used for analysis of the organic products on the FIDs. Light

  13. 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

  14. 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.

  15. 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 for Nano...

  16. 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...

  17. Synthesis of superheavy elements at the Dubna gas-filled recoil separator

    Energy Technology Data Exchange (ETDEWEB)

    Voinov, A. A., E-mail: voinov@jinr.ru [Joint Institute for Nuclear Research (Russian Federation); Collaboration: JINR (Dubna), LLNL (Livermore), ORNL (Oak Ridge), University of Tennessee (Knoxville), Vanderbilt University (Nashville), Research Institute of Atomic Reactors (Dimitrovgrad) Collaboration

    2016-12-15

    A survey of experiments at the Dubna gas-filled recoil separator (Laboratory of Nuclear Reactions, JINR, Dubna) aimed at the detection and study of the “island of stability” of superheavy nuclei produced in complete fusion reactions of {sup 48}Ca ions and {sup 238}U–{sup 249}Cf target nuclei is given. The problems of synthesis of superheavy nuclei, methods for their identification, and investigation of their decay properties, including the results of recent experiments at other separators (SHIP, BGS, TASCA) and chemical setups, are discussed. The studied properties of the new nuclei, the isotopes of elements 112–118, as well as the properties of their decay products, indicate substantial growth of stability of the heaviest nuclei with increasing number of neutrons in the nucleus as the magic number of neutrons N = 184 is approached.

  18. Synthesis and Magnetic Properties of Ni and Carbon Coated Ni by Levitational Gas Condensation (LGC

    Directory of Open Access Journals (Sweden)

    Young Rang Uhm

    2013-01-01

    Full Text Available The nickel (Ni, and carbon coated nickel (Ni@C nanoparticles were synthesized by levitaional gas condensation (LGC methods using a micron powder feeding (MPF system. Both metal and carbon coated metal nano powders include a magnetic ordered phase. The synthesis by LGC yields spherical particles with a large coercivity. The abnormal initial magnetization curve for Ni indicates a non-collinear magnetic structure between the core and surface layer of the particles. The carbon coated particles had a core structure diameter at and below 10 nm and were covered by 2-3 nm thin carbon layers. The hysteresis loop of the as-prepared Ni@Cs materials with unsaturated magnetization shows a superparamagnetic state at room temperature.

  19. High octane ethers from synthesis gas-derived alcohols. Final technical report, September 25, 1990--December 24, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Klier, K.; Herman, R.G.

    1994-05-01

    The objective of the research was to develop the methodology for the catalytic synthesis of ethers, primarily methyl isobutyl ether (MIBE) and methyl tertiary butyl ether (MTBE), directly from alcohol mixtures that are rich in methanol and 2-methyl-1-propanol (isobutanol). The overall scheme involves gasification of coal, purification and shifting of the synthesis gas, higher alcohol synthesis, and direct synthesis of ethers. The last stage of the synthesis involves direct coupling of synthesis gas-derived methanol and isobutanol that has been previously demonstrated by us to occur over superacid catalysts to yield MIBE and smaller amounts of MTBE at moderate pressures and a mixture of methanol and isobutene at low pressures. A wide range of organic resin catalysts and inorganic oxide and zeolite catalysts have been investigated for activity and selectivity in directly coupling alcohols, principally methanol and isobutanol, to form ethers and in the dehydration of isobutanol to isobutene in the presence of methanol. All of these catalysts are strong acids, and it was found that the organic and inorganic catalysts operate in different, but overlapping, temperature ranges, i.e. mainly 60--120{degrees}C for the organic resins and 90--175{degrees}C for the inorganic catalysts. For both types of catalysts, the presence of strong acid centers is required for catalytic activity, as was demonstrated by lack of activity of fully K{sup +} ion exchanged Nafion resin and zirconia prior to being sulfated by treatment with sulfuric acid.

  20. Design and Operation of the Synthesis Gas Generator System for Reformed Propane and Glycerin Combustion

    Science.gov (United States)

    Pickett, Derek Kyle

    Due to an increased interest in sustainable energy, biodiesel has become much more widely used in the last several years. Glycerin, one major waste component in biodiesel production, can be converted into a hydrogen rich synthesis gas to be used in an engine generator to recover energy from the biodiesel production process. This thesis contains information detailing the production, testing, and analysis of a unique synthesis generator rig at the University of Kansas. Chapter 2 gives a complete background of all major components, as well as how they are operated. In addition to component descriptions, methods for operating the system on pure propane, reformed propane, reformed glycerin along with the methodology of data acquisition is described. This chapter will serve as a complete operating manual for future students to continue research on the project. Chapter 3 details the literature review that was completed to better understand fuel reforming of propane and glycerin. This chapter also describes the numerical model produced to estimate the species produced during reformation activities. The model was applied to propane reformation in a proof of concept and calibration test before moving to glycerin reformation and its subsequent combustion. Chapter 4 first describes the efforts to apply the numerical model to glycerin using the calibration tools from propane reformation. It then discusses catalytic material preparation and glycerin reformation tests. Gas chromatography analysis of the reformer effluent was completed to compare to theoretical values from the numerical model. Finally, combustion of reformed glycerin was completed for power generation. Tests were completed to compare emissions from syngas combustion and propane combustion.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. Effects of beta-hydroxy-beta-methylbutyrate (HMB) on the expression of ubiquitin ligases, protein synthesis pathways and contractile function in extensor digitorum longus (EDL) of fed and fasting rats.

    Science.gov (United States)

    Gerlinger-Romero, Frederico; Guimarães-Ferreira, Lucas; Yonamine, Caio Yogi; Salgueiro, Rafael Barrera; Nunes, Maria Tereza

    2018-03-01

    Beta-hydroxy-beta-methylbutyrate (HMB), a leucine metabolite, enhances the gain of skeletal muscle mass by increasing protein synthesis or attenuating protein degradation or both. The aims of this study were to investigate the effect of HMB on molecular factors controlling skeletal muscle protein synthesis and degradation, as well as muscle contractile function, in fed and fasted conditions. Wistar rats were supplied daily with HMB (320 mg/kg body weight diluted in NaCl-0.9%) or vehicle only (control) by gavage for 28 days. After this period, some of the animals were subjected to a 24-h fasting, while others remained in the fed condition. The EDL muscle was then removed, weighed and used to evaluate the genes and proteins involved in protein synthesis (AKT/4E-BP1/S6) and degradation (Fbxo32 and Trim63). A sub-set of rats were used to measure in vivo muscle contractile function. HMB supplementation increased AKT phosphorylation during fasting (three-fold). In the fed condition, no differences were detected in atrogenes expression between control and HMB supplemented group; however, HMB supplementation did attenuate the fasting-induced increase in their expression levels. Fasting animals receiving HMB showed improved sustained tetanic contraction times (one-fold) and an increased muscle to tibia length ratio (1.3-fold), without any cross-sectional area changes. These results suggest that HMB supplementation under fasting conditions increases AKT phosphorylation and attenuates the increased of atrogenes expression, followed by a functional improvement and gain of skeletal muscle weight, suggesting that HMB protects skeletal muscle against the deleterious effects of fasting.

  8. Designed synthesis of nanoporous organic polymers for selective gas uptake and catalytic applications

    Science.gov (United States)

    Arab, Pezhman

    Design and synthesis of porous organic polymers have attracted considerable attentions during the past decade due to their wide range of applications in gas storage, gas separation, energy conversion, and catalysis. Porous organic polymers can be pre-synthetically and post-synthetically functionalized with a wide variety of functionalities for desirable applications. Along these pursuits, we introduced new synthetic strategies for preparation of porous organic polymers for selective CO2 capture and catalytic applications. Porous azo-linked polymers (ALPs) were synthesized by an oxidative reaction of amine-based monomers using copper(I) as a catalyst which leads to azo-linkage formation. ALPs exhibit high surface areas of up to 1200 m2 g-1 and have high chemical and thermal stabilities. The nitrogen atoms of the azo group can act as Lewis bases and the carbon atom of CO2 can act as a Lewis acid. Therefore, ALPs show high CO2 uptake capacities due to this Lewis acid-based interaction. The potential applications of ALPs for selective CO2 capture from flue gas, natural gas, and landfill gas under pressure-swing and vacuum swing separation settings were studied. Due to their high CO2 uptake capacity, selectivity, and regenerability, ALPs are among the best porous organic frameworks for selective CO2 capture. In our second project, a new bis(imino)pyridine-linked porous polymer (BIPLP-1) was synthesized and post-synthetically functionalized with Cu(BF4)2 for highly selective CO2 capture. BIPLP-1 was synthesized via a condensation reaction between 2,6-pyridinedicarboxaldehyde and 1,3,5-tris(4-aminophenyl)benzene, wherein the bis(imino)pyridine linkages are formed in-situ during polymerization. The functionalization of the polymer with Cu(BF4)2 was achieved by treatment of the polymer with a solution of Cu(BF4)2 via complexation of copper cations with bis(imino)pyridine moieties of the polymer. BF4- ions can act Lewis base and CO2 can act as a Lewis acid; and therefore

  9. Prebiotic Synthesis in Volcanic Discharges: Exposing Ash to Volcanic/Primordial Gas Atmospheres

    Science.gov (United States)

    Scheu, B.; Dingwell, D. B.; Cimarelli, C.; Bada, J.; Chalmers, J. H.; Burton, A. S.

    2017-12-01

    Few topics in natural science are as heavily debated as context for the emergence of life on Earth more than 3.5 billion years ago. The spark discharge experiments by Miller (1953) are widely recognized as the first efficient abiotic synthesis of organic compounds under simulated primitive Earth conditions; however, since then our understanding of conditions on the early Earth have significantly advanced. Still, considerable uncertainty remains regarding when, where and how the raw materials needed for prebiotic reactions and molecular evolution originated. Recently volcanic lightning has been successfully reproduced in rapid decompression experiments, showing a direct relation between amount of electrical discharges and the abundance of finer ash ejected. This correlation suggests that efficient fragmentation and particle clustering in the plume provide favorable conditions for charge generation and discharge. In the context of the origin of life, volcanic lightning is of special interest because within volcanic plumes the volcanic gases will mix with the primordial atmosphere, widening the possible gas spectrum. Here we present a first study on volcanic discharges generated from the energetic ejection of volcanic ash into different controlled atmospheres. Ash from Sakurajima volcano (Japan), well known for the electrical activity associated with its frequent explosive eruptions, was loaded in our experimental volcano (a shock-tube-based apparatus), slowly pressurized and ejected into atmospheres of various compositions (N2, CH4, NH3, CO2). We monitored ash ejection as well as charge generation and discharges. The recollected ash was analyzed for interesting prebiotic compounds. Analyses indicated that simple amino acids such as glycine were synthesized in the experiments as long as there was a reduced gas (either ammonia or methane) present. We are now carrying out a systematic series of analyses to determine whether essential prebiotic reagents are generated

  10. 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)

  11. 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

  12. Simulation of a process for the two-stage thermal conversion of biomass into the synthesis gas

    Science.gov (United States)

    Kosov, V. F.; Lavrenov, V. A.; Zaichenko, V. M.

    2015-11-01

    The paper presents results of simulation of a process for the two-stage thermal conversion of wood biomass into the synthesis gas. The first stage of process is pyrolysis of raw materials, the second stage is cracking of volatile pyrolysis products which blown through the char at a temperature of about 1000° C. Char is a porous biomass residue with carbon content about 90%. The simulation based on the results of experimental investigations of a pilot plant with capacity up to 50 kg of raw material per hour. The main result of simulation is estimation of an energy conversion efficiency of wood biomass into synthesis gas for three different operation modes. The first mode is conversion of biomass into fuel gas and char, and the char is not further used. The second mode is the same, but char used as fuel for producing heat for own demand of the process. The third mode includes gasification of char by means of water steam, aimed to obtaining an additional yield of synthesis gas. The simulation shown, that total efficiency of power plant was 17.1% in the first mode, 22.4% in the second mode and 22.6% in the third mode.

  13. Bioconversion of coal-derived synthesis gas to liquid fuels. Quarterly technical progress report, April 1, 1993--June 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Jain, M.K.; Worden, R.M.; Grethlein, H.

    1993-07-16

    The overall objective of the project is to develop two stage fermentation process for conversion of coal-derived synthesis gas to a mixture of alcohols. This is achieved in two steps. In the first step, B .methylotrophicum converts carbon monoxide (CO) to butyric and acetic acids. Subsequent fermentation of the acids by Clostridium acetobutylicum leads to the production of butanol and ethanol. The tasks for this quarter were: Development/isolation of superior strains for fermentation of syn gas; optimization of process conditions for fermentation of syn gas; evaluation of bioreactor configuration for improved mass transfer of syn gas; and optimization of process conditions for reducing carbon and electron loss by H{sub 2}-CO{sub 2} fermentation.

  14. Synthesis and characterization of tungsten carbide doped cobalt via gas-solid reaction in rotary bed reactor

    International Nuclear Information System (INIS)

    Tertuliano, R.S.C.; Araujo, C.P.B. de; Frota, A.V.V.M.; Moriyama, A.L.L.; Souza, C.P. de

    2016-01-01

    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 4 / H 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

  15. 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

  16. 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

  17. Bioconversion of coal-derived synthesis gas to liquid fuels. Final report, September 29, 1992--December 27, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Jain, M.K.; Worden, R.M.; Grethlein, H.E.

    1995-01-15

    The proposed research project consists of an integrated, two-stage fermentation and a highly energy-efficient product separation scheme. In the first fermentation, Butyribacterium methylotrophicum converts carbon monoxide (CO) into butyric acid and acetic acids which are then converted into butanol, ethanol, and a small amount of acetone in the second stage fermentation by Clostridium acetobutylicum. An advanced separation system process, based on pervaporation, removes the alcohols from the fermentation broth as they are formed, along with some of the hydrogen sulfide (H{sub 2}S), to minimize possible inhibition of the fermentations. This bioconversion process offers a critical advantage over conventional, catalytic processes for synthesis gas conversion: the microorganisms are several orders of magnitude more sulfur tolerant than metallic catalysts. The catalysts require sulfur removal to the parts per million level, while the microorganisms are unaffected by H{sub 2}S and carbonyl sulfide (COS) at one part per hundred--roughly the composition of sulfur in raw synthesis gas. During the two-year course of this project, the following major objectives have been accomplished: demonstrated long-term cell recycle of continuous fermentation of synthesis gas; demonstrated cell immobilization of Butyribacterium methylotrophicum; identified trickle-bed reactor as a viable alternative fermentation method; modulated metabolic pathways to increase C4 formation during synthesis gas fermentation; recovered carbon and electrons from H{sub 2} and CO{sub 2} with pathway modulation for increased C4 production; developed bacterial strains with improved selectivity for butyrate fermentation; demonstrated two-stage CO to alcohol fermentation; and concentrated alcohol from solventogenic fermentation by pervaporation.

  18. 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)

  19. 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.

  20. Computational fluid dynamics analysis of a synthesis gas turbulent combustion in a round jet burner

    Science.gov (United States)

    Mansourian, Mohammad; Kamali, Reza

    2017-05-01

    In this study, the RNG-Large Eddy Simulation (RNG-LES) methodology of a synthesis gas turbulent combustion in a round jet burner is investigated, using OpenFoam package. In this regard, the extended EDC extinction model of Aminian et al. for coupling the reaction and turbulent flow along with various reaction kinetics mechanisms such as Skeletal and GRI-MECH 3.0 have been utilized. To estimate precision and error accumulation, we used the Smirinov's method and the results are compared with the available experimental data under the same conditions. As a result, it was found that the GRI-3.0 reaction mechanism has the least computational error and therefore, was considered as a reference reaction mechanism. Afterwards, we investigated the influence of various working parameters including the inlet flow temperature and inlet velocity on the behavior of combustion. The results show that the maximum burner temperature and pollutant emission are affected by changing the inlet flow temperature and velocity.

  1. Synthesis of nanorods and mixed shaped copper ferrite and their applications as liquefied petroleum gas sensor

    Science.gov (United States)

    Singh, Satyendra; Yadav, B. C.; Prakash, Rajiv; Bajaj, Bharat; lee, Jae Rock

    2011-10-01

    Present paper reports the preparation and characterization of nanorods and mixed shaped (nanospheres/nanocubes) copper ferrite for liquefied petroleum gas (LPG) sensing at room temperature. The structural, surface morphological, optical, electrical as well as LPG sensing properties of the copper ferrite were investigated. Single phase spinel structure of the CuFe 2O 4 was confirmed by XRD data. The minimum crystallite size of copper ferrite was found 25 nm. The stoichiometry was confirmed by elemental analysis and it revealed the presence of oxygen, iron and copper elements with 21.91, 12.39 and 65.70 atomic weight percentages in copper ferrite nanorods. The band gap of copper ferrite was 3.09 and 2.81 eV, respectively for nanospheres/nanocubes and nanorods. The sensing films were made by using screen printing technology and investigated with the exposure of LPG. Our results show that the mixed shaped CuFe 2O 4 had an improved sensing performance over that of the CuFe 2O 4 nanorods, of which a possible sensing mechanism related to a surface reaction process was discussed. Sensor based on mixed shaped copper ferrite is 92% reproducible after one month. The role of PEG in the synthesis for obtaining nanospheres/nanocubes has also been demonstrated.

  2. Design and Development of a Wood-Fired Gasifier Prototype for Synthesis Gas Production and Analysis

    Directory of Open Access Journals (Sweden)

    Neres Ann S. Manguiat

    2015-12-01

    Full Text Available -Synthesis gas formation which can be transformed to useful compounds through biomass gasification is perceived as one promising process of biofuel production. A construction, design and development of an efficient and small-scale wood-fired gasifier prototype was made at Batangas State University. This study included the costs and specifications of materials, the design, components and percent conversion of the biomass to syngas by obtaining the amount of the residue. Set of operating conditions were determined so as to achieve a good performance of the gasifier; otherwise it adversely affected the operation of the prototype. The gasifier operates in a condition in which the air flow rate is 560 - 610 cm3 /min wherein the valve is half-open and the blower is turned on after 20 seconds. The gasifier will be closed after a minute of start-up. With these conditions, the gasifier works accordingly to a smooth operation. Syngas was composed of methane (2.32 % volume, carbon dioxide (10 % volume, carbon monoxide and minimal amount of hydrogen. Two (2 kg of woodchips with 90.75% conversion was the best amount of feed suited for the operation of the gasifier. This innovation comprises a method which efficiently converts the feedstock thereby enhancing the energy of the syngas produced with byproducts at minimum acceptable value. The wood-fired gasifier will be a very helpful tool in contributing to the resolution of pressing social and environmental problems such as energy security and local agricultural waste pollution.

  3. Synthesis of Improved Catalytic Materials for High-Temperature Water-gas Shift Reaction

    Directory of Open Access Journals (Sweden)

    Zara P. Cherkezova-Zheleva

    2015-12-01

    Full Text Available In this investigation, we report the preparation and characterization of Co-, Cu- and Mn-substituted iron oxide catalytic materials supported on activated carbon. Co-precipitation method and low temperature treatment were used for their synthesis. The influence of chemical composition, stoichiometry, particle size and dispersity on their catalytic activity was studied. Samples were characterized in all stages of their co-precipitation, heating and spend samples after catalytic tests. The obtained results from room and low temperature Mössbauer spectroscopy were combined with analysis of powder X-ray diffraction patterns (XRD. They revealed the preparation of nano-sized iron oxide materials supported on activated carbon. Relaxation phenomena were registered also for the supported phases. The catalytic performance in the water-gas shift reaction was studied. The activity order was as follows: Cu0.5Fe2.5O4 > Co0.5Fe2.5O4 > Mn0.5Fe2.5O4. Catalytic tests demonstrated very promising results and potential application of studied samples due to their cost-effective composition.

  4. Bioconversion of coal-derived synthesis gas to liquid fuels. Annual report, September 29, 1992--September 28, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Jain, M.K.; Worden, R.M.; Grethlein, H.E.

    1993-10-21

    The overall objective of the project is to develop and optimize a two-stage fermentation process for the conversion of coal derived synthesis gas in an mixture of alcohols. The goals include the development of superior strains with high product tolerance and productivity, optimization of process conditions for high volumetric productivity and product concentrations, integration and optimization of two stage syngas fermentation, evaluation of bioreactor configurations for enhanced mass transfer, evaluation of syngas conversion by a culture of Butyribacterium methyltrophicum and Clostridium acetobutylicum, development of a membrane based pervaporation system for in situ removal of alcohols, and development of a process for reduction of carbon and electron loss. The specific goals for year one (September 1992 - September 1993) were (1) development of a project work plan, (2) development of superior CO-utilizing strains, (3) optimization of process conditions for conversion of synthesis gas to a mixture of acids in a continuously stirred reactor (CSTR), (4) evaluation of different bioreactor configurations for maximization of mass transfer of synthesis gas, (5) development of a membrane based pervaporation system, and (6) reduction of carbon and electron loss via H{sub 2}CO{sub 2} fermentation. Experimentation and progress toward these goals are described in this report.

  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. 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.

  7. 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.

  8. Insect food for astronauts: gas exchange in silkworms fed on mulberry and lettuce and the nutritional value of these insects for human consumption during deep space flights.

    Science.gov (United States)

    Tong, L; Yu, X; Liu, H

    2011-10-01

    In this study, silkworm moth (Bombyx mori L.) larvae were regarded as an animal protein source for astronauts in the bioregenerative life support system during long-term deep space exploration in the future. They were fed with mulberry and stem lettuce leaves during the first three instars and the last two instars, respectively. In addition, this kind of environmental approach, which utilised inedible biomass of plants to produce animal protein of high quality, can likewise be applied terrestrially to provide food for people living in extreme environments and/or impoverished agro-ecosystems, such as in polar regions, isolated military bases, ships, submarines, etc. Respiration characteristics of the larvae during development under two main physiological conditions, namely eating and not-eating of leaves, were studied. Nutrient compositions of silkworm powder (SP), ground and freeze-dried silkworms on the 3rd day of the 5th instar larvae, including protein, fat, vitamins, minerals and fatty acids, were measured using international standard methods. Silkworms' respiration rates, measured when larvae were eating mulberry leaves, were higher than those of similar larvae that hadn't eaten such leaves. There was a significant difference between silkworms fed on mulberry leaves and those fed on stem lettuce in the 4th and 5th instars (P<0.01). Amounts of CO2 exhaled by the silkworms under the two physiological regimes differed from each other (P<0.01). There was also a significant difference between the amount of O2 inhaled when the insects were under the two physiological statuses (P<0.01). Moreover, silkworms' respiration quotient under the eating regime was larger than when under the not-eating regime. The SP was found to be rich in protein and amino acids in total; 12 essential vitamins, nine minerals and twelve fatty acids were detected. Moreover, 359 kcal could be generated per 100 gram of SP (dry weight).

  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. Influence of the Total Gas Flow at Different Reaction Times for CVD-Graphene Synthesis on Polycrystalline Nickel

    Directory of Open Access Journals (Sweden)

    M. P. Lavin-Lopez

    2016-01-01

    Full Text Available Optimization of the total gas flow (CH4+H2 during the reaction step for different reaction times for CVD-graphene synthesis on polycrystalline nickel foil using an atmospheric pressure set-up is reported. A thickness value related to number of graphene layers in each of the synthesized samples was determined using an Excel-VBA application. This method assigned a thickness value between 1 and 1000 and provided information on the percentage of each type of graphene (monolayer, bilayer, and multilayer deposited onto the polycrystalline nickel sheet. The influence of the total gas flow during the reaction step and the reaction time was studied in detail. Optical microscopy showed that samples were covered with different types of graphene, such as multilayer, few-layer, bilayer, and monolayer graphene. The synthesis variables were optimized according to the thickness value and the results were verified by Raman spectroscopy. The best conditions were obtained with a reaction temperature of 980°C, a CH4/H2 flow rate ratio of 0.07 v/v, a reaction time of 1 minute, and a total gas flow of 80 NmL/min. In the sample obtained under the optimized conditions, 80% of the area was covered with monolayer graphene and less than 1% with multilayer graphene.

  13. Conductive Polymer Synthesis with Single-Crystallinity via a Novel Plasma Polymerization Technique for Gas Sensor Applications

    Directory of Open Access Journals (Sweden)

    Choon-Sang Park

    2016-09-01

    Full Text Available This study proposes a new nanostructured conductive polymer synthesis method that can grow the single-crystalline high-density plasma-polymerized nanoparticle structures by enhancing the sufficient nucleation and fragmentation of the pyrrole monomer using a novel atmospheric pressure plasma jet (APPJ technique. Transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FT-IR, X-ray photoelectron spectroscopy (XPS, and field emission scanning electron microscopy (FE-SEM results show that the plasma-polymerized pyrrole (pPPy nanoparticles have a fast deposition rate of 0.93 µm·min−1 under a room-temperature process and have single-crystalline characteristics with porous properties. In addition, the single-crystalline high-density pPPy nanoparticle structures were successfully synthesized on the glass, plastic, and interdigitated gas sensor electrode substrates using a novel plasma polymerization technique at room temperature. To check the suitability of the active layer for the fabrication of electrochemical toxic gas sensors, the resistance variations of the pPPy nanoparticles grown on the interdigitated gas sensor electrodes were examined by doping with iodine. As a result, the proposed APPJ device could obtain the high-density and ultra-fast single-crystalline pPPy thin films for various gas sensor applications. This work will contribute to the design of highly sensitive gas sensors adopting the novel plasma-polymerized conductive polymer as new active layer.

  14. The economical production of alcohol fuels from coal-derived synthesis gas. Quarterly technical progress report No. 5, October 1, 1992--December 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    Two base case flow sheets have now been prepared. In the first, which was originally presented in TPR4, a Texaco gasifier is used. Natural gas is also burned in sufficient quantity to increase the hydrogen to carbon monoxide ratio of the synthesis gas to the required value of 1. 1 for alcohol synthesis. Acid gas clean up and sulfur removal are accomplished using the Rectisol process followed by the Claus and Beavon processes. About 10% of the synthesis gas is sent to a power generation unit in order to produce electric power, with the remaining 90% used for alcohol synthesis. For this process, the estimated installed cost is $474.2 mm. The estimated annual operating costs are $64.5 MM. At a price of alcohol fuels in the vicinity of $1. 00/gal, the pay back period for construction of this plant is about four years. The details of this case, called Base Case 1, are presented in Appendix 1. The second base case, called Base Case 2, also has a detailed description and explanation in Appendix 1. In Base Case 2, a Lurgi Gasifier is used. The motivation for using a Lurgi Gasifier is that it runs at a lower temperature and pressure and, therefore, produces by-products such as coal liquids which can be sold. Based upon the economics of joint production, discussed in Technical Progress Report 4, this is a necessity. Since synthesis gas from natural gas is always less expensive to produce than from coal, then alcohol fuels will always be less expensive to produce from natural gas than from coal. Therefore, the only way to make coal- derived alcohol fuels economically competitive is to decrease the cost of production of coal-derived synthesis gas. one method for accomplishing this is to sell the by-products from the gasification step. The details of this strategy are discussed in Appendix 3.

  15. 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.

  16. 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.

  17. Less sensitive electrocatalysts towards carbon monoxide for PEMFC fed by hydrogen produced from reforming gas; Recherche de catalyseurs peu sensibles a la presence de monoxyde de carbone pour piles a combustible PEMFC alimentees en gaz de reformage

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, A.C.

    2002-11-15

    The aim of this work was to prepare bimetallic catalysts based on platinum to elaborate anodes for fuel cells fed by hydrogen produced from reforming gas and containing thus some ppm of carbon monoxide. In order to avoid platinum poisoning, another metal, such as tin, was added. This leads to a more tolerant material to CO. A Pt-Sn catalyst supported on Vulcan XC-72 carbon was prepared by a chemical route, using a platinum carbonyl complex. This material was characterized by physical and chemical methods which indicate that it is formed by nano-structured Pt{sub 3}Sn particles. These particles have a narrow size distribution with a mean diameter of approximately 2 nm. Its activity towards CO, particularly under fuel cell conditions, was compared with a similar commercial E-TEK catalyst. This study shows that the catalyst prepared from the carbonyl precursor is less sensitive to CO than the commercial one. (author)

  18. 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.

  19. Supplementation with non-fibrous carbohydrates reduced fiber digestibility and did not improve microbial protein synthesis in sheep fed fresh forage of two nutritive values.

    Science.gov (United States)

    Tebot, I; Cajarville, C; Repetto, J L; Cirio, A

    2012-04-01

    To determine whether non-fibrous carbohydrate (NFC) supplementation improves fiber digestibility and microbial protein synthesis, 18 Corriedale ewes with a fixed intake level (40 g dry matter (DM)/kg BW0.75) were assigned to three (n = 6) diets: F = 100% fresh temperate forage, FG = 70% forage + 30% barley grain and FGM = 70% forage + 15% barley grain + 15% molasses-based product (MBP, Kalori 3000). Two experimental periods were carried out, with late (P1) and early (P2) vegetative stage forage. For P2, ewes were fitted with ruminal catheters. Forage was distributed at 0900 h, 1300 h, 1800 h and 2300 h, and supplement added at 0900 h and 1800 h meals. Digestibility of the different components of the diets, retained N and rumen microbial protein synthesis were determined. At the end of P2, ruminal pH and N-NH3 concentration were determined hourly for 24 h. Supplementation increased digestibility of DM (P digestibility (P = 0.043) in both periods, with greater values in P2 (P = 0.008) for the three diets. Daily mean ruminal pH differed (P digestibility in supplemented diets could not be attributed to pH changes. The mean ruminal concentration of N-NH3 was 18.0 mg/dl, without differences among treatments or sampling hours. Microbial protein synthesis was greater in P2 (8.0 g/day) than in P1 (6.1 g/day; P = 0.006), but treatments did not enhance this parameter. The efficiency of protein synthesis tended to be lower in supplemented groups (16.4, 13.9 and 13.4 in P1, and 20.8, 16.7 and 16.2 g N/kg digestible OM ingested in P2, for F, FG and FGM, respectively; P = 0.07) without differences between supplements. The same tendency was observed for retained N: 2.55, 1.38 and 1.98 in P1, and 2.28, 1.23 and 1.10 g/day in P2, for F, FG and FGM, respectively; P = 0.05). The efficiency of microbial protein synthesis was greater in P2 (P = 0.007). In conclusion, addition of feeds containing NFCs to fresh temperate forage reduced the digestibility of cell walls and did not improve

  20. 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

  1. Chemical equilibria in methanol synthesis including the water-gas shift reaction: a critical reassessment

    NARCIS (Netherlands)

    Graaf, Geert; Winkelman, Jozef G.M.

    2016-01-01

    A large number of experimental equilibrium constants for the reactions involved in methanol synthesis were collected or calculated from several literature sources. Equilibrium relationships were derived from basic thermochemical data and subsequently fitted to the experimental results by adapting

  2. Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup, and Oxygen Separation Equipment; Task 2: Gas Cleanup Design and Cost Estimates -- Black Liquor Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Nexant Inc.

    2006-05-01

    As part of Task 2, Gas Cleanup and Cost Estimates, Nexant investigated the appropriate process scheme for removal of acid gases from black liquor-derived syngas for use in both power and liquid fuels synthesis. Two 3,200 metric tonne per day gasification schemes, both low-temperature/low-pressure (1100 deg F, 40 psi) and high-temperature/high-pressure (1800 deg F, 500 psi) were used for syngas production. Initial syngas conditions from each of the gasifiers was provided to the team by the National Renewable Energy Laboratory and Princeton University. Nexant was the prime contractor and principal investigator during this task; technical assistance was provided by both GTI and Emery Energy.

  3. Conceptual design and exergy analysis of an integrated structure of natural gas liquefaction and production of liquid fuels from natural gas using Fischer-Tropsch synthesis

    Science.gov (United States)

    Niasar, Malek Shariati; Amidpour, Majid

    2018-01-01

    In this paper, utilizing absorption refrigeration system as an alternative to compression refrigeration system of MFC refrigeration cycle in an integrated superstructure with the main aim of reduction in required energy is investigated. High-energy consumption in such units is reduced because of the removal of a stage of the compression system, while the possibility of using waste energy through employing of absorption refrigeration system can be provided. A superstructure including cogeneration of heating, cooling and power for LNG production and liquid fuels using Fischer-Tropsch synthesis are investigated. Exergy analysis shows that the greatest amount of exergy destruction of equipment is related to the compressors by 28.99% and the lowest exergy destruction is related to the gas turbine by 0.17%. Integrated structure has overall thermal efficiency of 90% and specific power of 0.1988 kW h/(kg LNG)-1.

  4. 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.

  5. The start-up of a gas turbine engine using compressed air tangentially fed onto the blades of the basic turbine

    Science.gov (United States)

    Slobodyanyuk, L. K.; Dayneko, V. I.

    1983-01-01

    The use of compressed air was suggested to increase the reliability and motor lifetime of a gas turbine engine. Experiments were carried out and the results are shown in the form of the variation in circumferential force as a function of the entry angle of the working jet onto the turbine blade. The described start-up method is recommended for use with massive rotors.

  6. Bioconversion of coal derived synthesis gas to liquid fuels. Final quarterly technical progress report, July 1, 1993--September 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Jain, M.K.; Worden, R.M.; Grethlein, H.

    1993-10-25

    The overall objective of the project is to develop an integrated two stage fermentation process for conversion of coal-derived synthesis gas to a mixture of alcohols. This is achieved in two steps. In the first step, Butyribacterium methylotrophicum converts carbon monoxide (CO) to butyric and acetic acids. Subsequent fermentation of the acids by Clostridium acetobutylicum leads to the production of butanol and ethanol. The tasks for this quarter were: (1) development/isolation of superior strains for fermentation of syngas, (2) optimization of process conditions for fermentation of syngas, (3) evaluation of bioreactor configuration for improved mass transfer of syngas, (4) development of a membrane-based pervaporation system, (5) optimization of process conditions for reducing carbon and electron loss by H{sub 2}-CO{sub 2} fermentation, and (6) synthesis gas fermentation in single-stage by co-culture. Progress is reported in isolation of CO utilizing anaerobic strains; investigating the product profile for the fermentation of syngas by B. methylotrophicum; and determining the effect of carbon monoxide on growth of C. acetobutylicum.

  7. Mechanochemical synthesis in the Li-Mg-N-D system under deuterium gas: a neutron diffraction study.

    Science.gov (United States)

    Li, Z; Zhang, J; Latroche, M; Wang, S; Jiang, L; Du, J; Cuevas, F

    2016-09-14

    The Mg(NH2)2/2LiH mixture is considered as one of the most valuable reversible hydrogen storage systems for feeding PEM fuel cells. In this paper, we investigate the mechanochemical synthesis in the Li-Mg-N-H system under deuterium gas, using Li3N and Mg as reactants, and the structural and sorption properties of the intermediate and final products mainly by means of neutron powder diffraction. Mechanochemistry leads to the end formation of amorphous Mg(ND2)2, which crystallizes upon heating above 425 K. During synthesis, a novel cation-mixed nitride/imide phase of simplified composition Li3MgN2D has been unveiled as the intermediate phase. It crystallizes in the cubic disordered anti-fluorite type structure (S.G. Fm3[combining macron]m) with a lattice parameter of 4.996 Å at room temperature. Deuterium absorption in this compound occurs through an original solid solution type mechanism ending with the imide compound β-Li2MgN2D2. The conjoint use of mechanochemistry under deuterium gas and in situ neutron diffraction techniques offers new avenues for better characterization of the efficient hydrogen storage materials. In particular, this work highlights the unexpected role of intermediate nitride/imide phases in the Li-Mg-N-H system.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.)

  13. Synthesis, characterization and gas sensitivity of MoO3 nanoparticles

    Indian Academy of Sciences (India)

    TECS

    High sensitivity gas sensing assumes great importance in view of the plethora of health hazards related to poisonous gases that are associated with industrial and automobile exhausts. Thus, the requirement of gas sensors to sense such harmful gases is indubitable and with this requirement comes the demand for highly ...

  14. Evaluation of venous blood gas levels, blood chemistry and haemocytometric parameters in milk fed veal calves at different periods of livestock cycle.

    Science.gov (United States)

    Giambelluca, S; Fiore, E; Sadocco, A; Gianesella, M; Vazzana, I; Orefice, T; Morgante, M

    2016-12-01

    An evaluation of blood chemistry profile in relation to specific stages of livestock cycle can help better understand variations in physiological conditions in order to adjust management systems to animal needs. In addition to basal hematological investigation, the acid-base balance and blood gases are essential tools in evaluating metabolism in calves. The relationship between blood gas parameters, diet and growth should be further investigated. The aim of this study was to evaluate changes in acid-base status, blood gases, serum chemistry and hematological parameters in veal calves at different periods of livestock cycle. One hundred twenty-eight healthy cross breeding calves were enrolled in a farm in North-East Italy. Blood samplings were carried out from the jugular vein on day 1 (t1), 60 (t2) and 150 (t3) after arrival. Blood gas analysis was performed and hematological parameters were evaluated. One-way ANOVA and Tukey-Kramer post-hoc test were performed to assess differences between blood parameter values at the different periods. The main differences in blood gas parameter levels during the livestock cycle concerned pH, Base Excess and HCO3 with higher values recorded in t3. Urea, creatinine, gamma-glutamyl transpeptidase and bilirubin mean values were significantly higher in t1 than in t2 and t3. Aspartate aminotransferase increased from t1 to t2 and t3. Alkaline Phosphatase was higher in t2. Fe levels severely dropped in t2 and in t3, and the decrease led to a restrained but significant reduction in haemoglobin values. A correspondent decrease in the other haemocytometric parameters was found.

  15. Urinary excretion of purine derivatives, microbial protein synthesis, nitrogen use, and ruminal fermentation in sheep and goats fed diets of different quality.

    Science.gov (United States)

    Carro, M D; Cantalapiedra-Hijar, G; Ranilla, M J; Molina-Alcaide, E

    2012-11-01

    The objective of this study was to compare N balance, microbial N flow (MNF) estimated from purine derivatives (PD) urinary excretion, and its variation when estimated using purine bases:N ratios in liquid associated bacteria (LAB) from models reported in the literature (MNF - response models) or measured ratios in liquid and solid-associated bacterial (SAB) pellets (MNF-LAB+SAB), diet digestibility, and rumen fermentation variables in sheep and goats fed 3 different practical, quality diets to study interspecies differences concerning N use as accurately as possible. Four mature female Merino sheep and 4 mature female Granadina goats, each fitted with a ruminal cannula, were used in 3 × 3 Latin square design with an extra animal. Two experimental diets had a forage-to-concentrate ratio of 70:30 (DM basis) with alfalfa hay (ALC) or grass hay (GRC) as forage, and the third diet contained 70% concentrate and 30% alfalfa hay (CAL). All animals were fed the diets at a daily rate of 56 g/kg BW(0.75) to minimize feed selection. Digestibility of nutrients was similar (P = 0.16 to 0.88) in the 2 species, but some animal species × diet interactions (P = 0.01 to 0.04) were detected. There were small differences between the fermentation patterns of both animal species. Goats showed decreased VFA concentrations (P = 0.005) and butyrate proportions (P = 0.04), and greater acetate proportions (P = 0.02) compared with sheep, whereas N intake and percentage of N intake excreted in feces were similar in both species (P = 0.58 and 0.15, respectively), the percentage excreted via the urine was greater in goats compared with sheep (P excretion, but goats showed a greater excretion of allantoin (P = 0.01) and decreased excretion of xanthine (P = 0.008) and hypoxanthine (P = 0.007) compared with sheep. In general, differences between sheep and goats were more pronounced for the medium-quality diet (GRC) compared with those of high-quality diet (ALC and CAL). The greater urinary losses

  16. Short communication: Effects of lysolecithin on milk fat synthesis and milk fatty acid profile of cows fed diets differing in fiber and unsaturated fatty acid concentration.

    Science.gov (United States)

    Rico, D E; Ying, Y; Harvatine, K J

    2017-11-01

    Thirteen multiparous Holstein cows were used in a crossover design that tested the effect of lysolecithin in diets differing in neutral detergent fiber (NDF) and unsaturated fatty acid (FA) concentrations. Experimental periods were 20 d in length and included two 10-d phases. A standard fiber and lower fat diet was fed the first 10 d (30.5% NDF, no added oil, lower-risk phase) and a lower NDF and higher oil diet was fed during the second 10 d (29.0% NDF and 2% oil from whole soybeans and soybean oil, high-risk phase). Treatments were control and 10 g/d of lysolecithin (LYSO) extended in a ground corn carrier. Milk was sampled on d 0, 5, and 10 of each phase for determination of fat and protein concentration and FA profile. We found no effect of treatment or treatment by time interaction for dry matter intake, milk yield, or milk protein concentration. A treatment by time interaction was observed for milk fat concentration and yield. Milk fat concentration was higher in LYSO on d 5 of the lower-risk phase, but decreased progressively in both treatments during the high-risk phase. Milk fat yield was not different among treatments during the lower-risk phase, but was lower in LYSO on d 15 and tended to be lower on d 20 during the high-risk phase. Concentrations of milk de novo FA decreased and preformed FA increased during the high-risk phase, but we found no effect of treatment or treatment by time interactions. We noted an effect of time, but no treatment or treatment by time interactions for milk trans FA isomers. Briefly, trans-11 C18:1 and cis-9,trans-11 conjugated linoleic acid progressively decreased as trans-10 C18:1 and trans-10,cis-12 conjugated linoleic acid progressively increased during the high-risk phase. The LYSO increased milk fat concentration when feeding a higher fiber and lower unsaturated FA diet, but decreased milk fat yield when feeding a lower fiber and higher unsaturated FA diet, although biohydrogenation pathways and capacity did not appear

  17. Synthesis and characterization of nano crystalline nickel zinc ferrite for chlorine gas sensor at room temperature

    Science.gov (United States)

    Pawar, C. S.; Gujar, M. P.; Mathe, V. L.

    2015-06-01

    Nano crystalline Nickel Zinc ferrite (Ni0.25Zn0.75Fe2O4) thin films were synthesized by Sol Gel method for gas response. The phase and microstructure of the obtained Ni0.25Zn0.75Fe2O4 thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The nanostructured Ni0.25Zn0.75Fe2O4 thin film shows single spinel phase. Magnetic study was obtained with the help of VSM. The effects of working temperature on the gas response were studied. The results reveal that the Ni0.25Zn0.75Fe2O4 thin film gas sensor shows good selectivity to chlorine gas at room temperature. The sensor shows highest sensitivity (˜50%) at room temperature, indicating its application in detecting chlorine gas at room temperature in the future.

  18. 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.)

  19. Synthesis gas production via catalytic partial oxidation reforming of liquid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Cheekatamarla, P.K.; Finnerty, C.M. [NanoDynamics Energy Inc., 901 Fuhrmann Boulevard, Buffalo, NY 14203 (United States)

    2008-10-15

    This work deals with the performance of waterless catalytic partial oxidation (CPOX)-based catalytic reformer system fed by different liquid fuels including ethanol, isooctane, hexadecane, synthetic JP8, kerosene and diesel for solid oxide fuel cell applications. The effect of different fuel components on product composition was studied and the operational parameters were optimized to provide a stable reforming performance. The system provided negligible pressure drop combined with the simpler system design due to the lack of water requirement making the POX reformer an attractive choice. (author)

  20. Effects of a multi-strainBacillusspp. direct-fed microbial and a protease enzyme on growth performance, nutrient digestibility, blood characteristics, fecal microbiota, and noxious gas emissions of grower pigs fed corn-soybean-meal-based diets-A meta-analysis.

    Science.gov (United States)

    Payling, L; Kim, I H; Walsh, M C; Kiarie, E

    2017-09-01

    Three studies involving 352 grower pigs were conducted to determine the effects of dietary supplementation with multistrain spp. direct-fed microbial (DFM) and protease, alone or in combination, on growth performance, nutrient digestibility, blood characteristics, fecal microbiota, and noxious gas emissions, and to use a meta-analysis to increase the reliability of the findings. Treatments ( = 4) were set up as a 2 × 2 factorial design with 2 levels of protease (0 and 5.000/6.000 units/kilogram of feed [U/KG]) and 2 levels of DFM (0 and 1.5 × 10 colony forming units/gram of feed [CFU/G]), plus a protease + DFM combination. Pigs were housed in groups of 3 or 4/pen with 8 replicate pens/treatment. Experimental diets were fed for 42 d and feed intake and BW were measured weekly. Fecal samples were collected at d 42 and analyzed to determine apparent total tract digestibility (ATTD). Fecal counts of and coliforms, and noxious gas emissions were measured. Blood samples were taken by anterior vena cava puncture to measure blood urea nitrogen (BUN) and creatinine. Data from the 3 studies were pooled and analyzed as a 2 × 2 factorial using the Fit Model platform of JMP 11 (SAS Inst. Inc., Cary, NC). Means separation was determined using Tukey's honest significant difference test. The main effect of protease and DFM increased: BW at 42 d, overall ADG, and overall G:F compared to the control ( 0.05); however, the protease + DFM combination was the only treatment to improve ADG and G:F in all phases compared to the control. The main effect of protease increased ATTD of DM, nitrogen (N), and ADF ( < 0.04). The main effect of DFM increased ATTD of DM, N, GE, DE, ADF, and fat ( < 0.02). There was a trend for an interaction between protease and DFM for ATTD of GE and DE ( < 0.08) because the protease + DFM combination increased energy digestibility more than the additive effects of the protease and DFM alone. The main effects of protease and DFM decreased fecal ammonia

  1. 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.

  2. Rapid pressure swing absorption cleanup of post-shift reactor synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Sirkar, K.K.; Majumdar, S.; Bhaumik, S.

    1992-01-31

    In order to increase the production rate of purified gas stream, a new hollow fiber module has been fabricated with more number of hollow fibers. A few experiments have also been carried out using a CO{sub 2}-N{sub 2} feed gas mixture and water as an absorbent in the new module. With the new module, it was possible to increase the production rate of purified gas by a significant amount while the cycle time for vacuum desorption was considerably reduced. Preparations are now being made to study the absorption behavior of CO{sub 2}-N{sub 2} gas mixture with a reactive absorbent liquid such as aqueous diethanolamine solution.

  3. 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

  4. 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.

  5. 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

  6. Electrochemical synthesis of Mo{sub 2}C catalytical coatings for the water-gas shift reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, S.A.; Dubrovskiy, A.R. [Inst. of Chemistry, Kola Science Centre RAS, Apatity, Murmansk Region (Russian Federation); Rebrov, E.V.; Schouten, J.C. [Lab. of Chemical Reactor Engineering, Eindhoven Univ. of Tech., Eindhoven (Netherlands)

    2007-10-15

    The electroreduction of CO{sub 3}{sup 2-} ions on a molybdenum cathode in a NaCl-KCl-Li{sub 2}CO{sub 3} melt was studied by cyclic voltammetry. The electrochemical synthesis of Mo{sub 2}C on molybdenum substrates has been performed at 1123 K for 7 h with a cathodic current density of 5 mA cm{sup -2}. If molybdenum carbide is present as a thin (ca. 500 nm) film on a molybdenum substrate (Mo{sub 2}C/Mo), its catalytic activity in the water gas-shift reaction is enhanced by at least an order of magnitude compared to that of the bulk Mo{sub 2}C phase. (orig.)

  7. Trimethyl(phenylsilane — a precursor for gas phase processes of SiCx:H film deposition: Synthesis and characterization

    Directory of Open Access Journals (Sweden)

    Evgeniya N. Ermakova

    2015-12-01

    Full Text Available The technique of synthesis and purification of trimethyl(phenylsilane PhSiMe3, allowing to obtain the product with high yield. Individuality of the product was confirmed by elemental analysis for C, H, Si was developed. IR, UV and 1H NMR-spectroscopic studies were used to define its spectral characteristics. Complex thermal analysis and thermogravimetry defined thermoanalytical behavior of PhSiMe3 in an inert atmosphere. Tensimetric studies have shown that the compound has sufficient volatility and thermal stability for use as a precursor in the process of chemical vapor deposition (CVD. The composition and temperature limits of the possible crystalline phase complexes in equilibrium with the gas phase of different composition has been determined by method of thermodynamic modeling. Calculated CVD diagrams allow us to select the optimal conditions of film deposition. The possibility of using trimethyl(phenylsilane in CVD processes for producing dielectric films of hydrogenated silicon carbide has been demonstrated.

  8. Evaluation of isoquinoline alkaloid supplementation levels on ruminal fermentation, characteristics of digestion, and microbial protein synthesis in steers fed a high-energy diet.

    Science.gov (United States)

    Aguilar-Hernández, J A; Urías-Estrada, J D; López-Soto, M A; Barreras, A; Plascencia, A; Montaño, M; González-Vizcarra, V M; Estrada-Angulo, A; Castro-Pérez, B I; Barajas, R; Rogge, H I; Zinn, R A

    2016-01-01

    Four Holstein steers with ruminal and duodenal cannulas were used in a 4 × 4 Latin square design to examine the effect of daily intake of 0, 2, 4 or 6 g/steer of standardized plant extract containing a mixture of quaternary benzophenanthridine alkaloids and protopine alkaloids (QBA+PA) on the characteristics of ruminal fermentation and characteristics of digestion. The basal diet consisted of a steam-flaked corn-based finishing diet that contained 62% corn and 12% sudangrass hay and the rest of diet was composed of mainly dried distillers grains, molasses, fat, and minerals. The source of QBA+PA used was Sangrovit-RS (Phytobiotics Futterzusatzstoffe GmbH, Eltville, Germany) and supplementation levels of 2, 4, and 6 g Sangrovit-RS∙steer∙d, which represented a net daily ingestion of approximately 6, 12, and 18 mg of QBA+PA compounds, respectively. Inclusion of QBA+PA linearly increased ( = 0.04) flow to the duodenum of nonammonia N and linearly decreased ( < 0.01) duodenal flows of ammonia N. Ruminal microbial efficiency (duodenal microbial N; g/kg OM fermented in the rumen) and protein efficiency (duodenal nonammonia N; g/g N intake) were increased ( < 0.05) as the level of QBA+PA increased. There were no effects of QBA+PA supplementation on ruminal, postruminal, and total tract digestion of OM, starch, and NDF, but postruminal and total tract digestion of N increased ( < 0.01) as the level of QBA+PA increased. Digestible energy of the diet tended to increase (linear affect, = 0.09) with QBA+PA supplementation. Ruminal pH and total VFA molar concentrations were not different between treatments. Ruminal NH-N concentration linearly decreased ( = 0.02) with QBA+PA supplementation. Ruminal molar proportion of acetate increased ( = 0.04) as the supplementation level of QBA+PA increased. It is concluded that QBA+PA supplementation enhances efficiency of N utilization in feedlot steers fed a steam-flaked corn-based finishing diet. This effect was due, in part, to

  9. 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.

  10. 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.

  11. Synthesis of Ce-doped In2O3 nanostructure for gas sensor applications

    Science.gov (United States)

    Liu, Xiaojing; Jiang, Li; Jiang, Xiumei; Tian, Xueying; Sun, Xin; Wang, Yanli; He, Weidong; Hou, Peiyu; Deng, Xiaolong; Xu, Xijin

    2018-01-01

    Nanostructured materials with advantages in large surface-to-volume ratio and high specific surface area have demonstrated great potential in improving the gas sensing property because these structural and morphology features provide improved surface sensing activities. In this work, porous Ce-doped In2O3 nanospheres have been successfully prepared using a facile hydrothermal method, and their morphology, microstructure, and gas-sensing properties were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and gas sensing testing (GST). Ce doping not only enhances the response value and reduces response-recovery time but also lowers the operating temperature and retains good stability. The possible reasons for enhanced sensing properties of as-prepared Ce-doped In2O3 sensors were also proposed.

  12. Positions and synthesis of the seminar on the market of the natural gas

    International Nuclear Information System (INIS)

    Vasquez R, Raul

    1996-01-01

    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

  13. Effects of xylanase supplementation on growth performance, nutrient digestibility, blood parameters, fecal microbiota, fecal score and fecal noxious gas emission of weaning pigs fed corn-soybean meal-based diet.

    Science.gov (United States)

    Lan, Ruixia; Li, Tianshui; Kim, Inho

    2017-09-01

    This study was conducted to evaluate the effects of xylanase supplementation on nutrient digestibility, growth performance, blood parameters, fecal microflora shedding, fecal score and fecal noxious gas emission of weaning pigs fed corn-soybean meal based diet. A total of 150 weaning pigs with an average initial body weight (BW) of 7.85 ± 0.93 kg were randomly allocated to three treatments based on BW and sex (10 replicate pens with five pigs, two gilts and three barrows) were used in this 42-day trial. Dietary treatments were: (1) CON, basal diet; (2) X1, basal diet +0.005% xylanase; (2) X2, basal diet +0.01% xylanase. The xylanase supplementation linearly increased (P < 0.05) average daily gain (ADG), and gain : feed ratio (G:F) from days 29 to 42 and the in overall period, dry matter, nitrogen and energy digestibility, and fecal Lactobacilli counts, and linearly decreased (P < 0.05) blood urea nitrogen (BUN) concentration, fecal NH 3 and H 2 S emission. Additionally, at weeks 5 and 6, there was a linear decrease in fecal score with xylanase supplementation. In conclusion, dietary supplementation of xylanase improved growth performance, nutrient digestibility, shifted microbiota by increasing fecal Lactobacillus counts, decreased BUN concentration, fecal score, and fecal NH 3 and H 2 S emission in weaning pigs. © 2017 Japanese Society of Animal Science.

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

    Indian Academy of Sciences (India)

    1995; Kodas and Hampden-Smith 1999). He also measured precursor drop size precisely. He found that bimodal particle. Figure 2. Kinetics in thin film deposition. size distributions were produced, suggesting that both one- particle-per-drop and gas-to-particle conversion mechanisms were involved in spray pyrolysis.

  15. Synthesis of shape-controlled ZnSn(OH6 and gas sensing properties

    Directory of Open Access Journals (Sweden)

    HAN Lixian

    2013-02-01

    Full Text Available Monodisperse ZnSn(OH6(ZHS microcrystallites(MCs with two morphologies have been prepared through a facile preparation method without complicated steps,advanced experimental conditions or equipments.The morphology and compositional characteristics of the 3D hierarchitectures(HAs of ZHS MCs were investigated by various techniques such as XRD,FESEM,TEM,UV-vis spectra,BET.In the reaction system the morphology evolution from cube to sphere was controlled with adding different concentration of NH4OH.The gas sensors based on ZHS exhibited a good gas sensitivity to HCHO.However,the gas sensors based on spherical ZHS MCs exhibited the higher sensitivity,shorter recovery time and good reproducibility to HCHO than those of cubic ZHS MCs.More importantly,it was found that spherical ZHS MCs with ~600 nm size had the best gas-sensing properties owing to more oxygen vacancy defects,less band gap energy,and larger active surface area.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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....

  1. Synthesis, characterization and gas sensitivity of MoO3 nanoparticles

    Indian Academy of Sciences (India)

    Nanoparticles of molybdenum oxide were synthesized using the citrate sol–gel method and characterized using scanning electron microscopy and X-ray diffraction techniques. The sensitivity of the material to the presence of various gases was analysed and the particles showed higher sensitivity towards NO2 gas.

  2. 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.

  3. 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.

  4. Synthesis and characterization of WC-Co nanosized composite powders with in situ carbon and gas carbon sources

    Science.gov (United States)

    Yang, Qiumin; Yang, Jiangao; Yang, Hailin; Su, Wei; Ruan, Jianming

    2016-07-01

    This study presented nanosized WC-Co composite powders synthesized using a one-step reduction-carbonization process with a combination of CH4/H2 as a gas carbon source and soluble starch as an in situ carbon source. The results of carbon analysis and X-ray diffraction revealed that WC-Co nanocomposite powders with a pure WC and Co phase could be obtained at 1100 °C after 0.5 h. A higher gas flow ratio of CH4/H2 during the reduction-carbonization process led to a higher total carbon content of the sample. A field emission scanning electron microscope confirmed that the particles in the WC-6 wt% Co composite powders had the lowest average size of 43 nm with equiaxed shapes. A sintering neck was observed in the WC-3 wt% Co composite powders whereas faceted particles were found in the WC-12 wt% Co composite powders. Moreover, this method has advantages of simple processing, rapid synthesis and good applicability in potential industry application.

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. Analytical control of the synthesis of the trithion and its precursors by gas chromatography

    International Nuclear Information System (INIS)

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

    1979-01-01

    The synthesis of pesticide trithion and its percursors has been controlled by G.L.C. selecting the best separation conditions and responses. The following columns have been used: 20% FFAP on chromosorb W (a,w.) D.M.C.S. for organophosphate precursor; glass column of 5% Silicone SE-30 on chromosorb G (a.w.) D.M.C.S. for S-(p-chlorophenyl-chloromethyl) and 12% silicone SE-30 modified with 8% of neopentil-glicolsuccinate for trithion. The relative retention times, retention indices and relative responses for trithion and its precursors have been calculated. (author)

  10. Ultraviolet-gas phase and -photocatalytic synthesis from CO and NH3. [photolysis products

    Science.gov (United States)

    Hubbard, J. S.; Voecks, G. E.; Hobby, G. L.; Ferris, J. P.; Williams, E. A.; Nicodem, D. E.

    1975-01-01

    Ammonium cyanate is identified as the major product of the photolysis of gaseous NH3-CO mixtures at 206.2 or 184.9 nm. Lesser amounts of urea, biurea, biuret semicarbazide, formamide and cyanide are observed. A series of 18 reactions underlying the formation of photolysis products is presented and discussed. Photocatalytic syntheses of C-14-urea, -formamide, and -formaldehyde are carried out through irradiation of (C-14)O and NH3 in the presence of Vycor, silica gel, or volcanic ash shale surfaces. The possible contributions of the relevant reactions to the abiotic synthesis of organic nitrogen compounds on Mars, the primitive earth, and in interstellar space are examined.

  11. Synthesis gas production through redox cycles of bimetallic oxides and methane

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, M.I.S.; Vigil, M.D.D.; Gutierrez, J.S.; Collins-Martinez, V.; Ortiz, A.L. [Centro de Investigacion en Materiales Avanzados, Chihuahua, Chih (Mexico). Dept. de Quimica de Materiales

    2009-01-15

    High-purity hydrogen is required by fuel cells to produce electricity with high efficiency and reduced emissions. Therefore, new and cost effective technologies must be developed that can produce hydrogen to supply the increased demand of the current world market. These new technologies have to overcome several challenges such as large size, weight and cost, high temperature requirements for the process and other associated obstacles such as slow start-ups, storage and transportation issues. Hydrogen production through the partial oxidation of methane (POX) is a well known technology at industrial scale. This paper examined the synthesis, characterization and evaluation of iron (Fe) cerium (Ce) zirconium (Zr) with different Fe to CeZr ratios as oxygen carrier to produce syngas through the partial oxidation of methane. The paper also examined the effect of adding nickel (Ni) to FeCeZr as a catalyst to promote the partial oxidation and the proper assessment of the carbon formation within the reaction system. The paper described the experiment with particular reference to synthesis, characterization and reaction evaluation. The results were presented using X-ray diffraction; crystallite size and BET surface area; reaction evaluation by TGA; and evaluation of the partial oxidation of methane. Experimental values showed a clear trend towards the partial oxidation of methane reaction with samples containing Ni. 28 tabs., 4 tabs., 2 figs.

  12. 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.

  13. 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.

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

    Indian Academy of Sciences (India)

    The H2S sensing properties of the SnO2 films were investigated with different annealing temperatures and H2S gas concentrations. It was found that the annealing temperature significantly affects the sensitivity of the SnO2 to the H2S. The sensitivity was found to be maximum for the film annealed at temperature 950°C at ...

  15. 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.

  16. 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)

  17. Promotion by Cs(I) and poisoning by T1(I) of the Cu/ZnO catalysts for methanol synthesis and the water gas shift reaction

    International Nuclear Information System (INIS)

    Bybell, D.G.; Deutsch, P.P.; Herman, R.G.; Himelfarb, P.B.; Nunan, J.C.; Young, C.W.; Bogdan, C.E.; Simmons, C.W.; Klier, K.

    1986-01-01

    In the present work, the effects of univalent thallium, the solution chemistry of which is in many respects identical to that of the heavy alkali Rb and Cs ions (6), utilized as a dopant in the Cu/ZnO catalyst has been investigated. However, it is noted that the high temperature chemistry of T1(I) is more complex than that of the alkali ions in that the counter ions of the T1(I) ion decompose more easily than those of the alkali ions and that T1(I) can be oxidized to T1(III) under certain conditions. They present evidence that the effects of the T1(I) dopant on the Cu/ZnO catalysts, in surface concentrations comparable to those of the most effective Cs(I) promoter, on both methanol synthesis and the WGS reaction, are diametrically opposite to those of the alkali metal ions. In deed, the T1(I) ions behave rather as nearly inert additives for the WGS reaction, as a mild poison for methanol synthesis in the absence of H 2 O or CO 2 in the synthesis gas, and as a severe poison for methanol synthesis in a ternary H 2 O/CO/H 2 synthesis gas. The analysis of the results indicates that the hydrogen activating sites are poisoned by the thallium ions

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Microbial protein synthesis in young steers fed with grass silage and extruded corn Síntesis de proteína microbiana en novillos jóvenes alimentados con ensilaje de praderas y maíz extruido

    Directory of Open Access Journals (Sweden)

    Claudia Barchiesi-Ferrari

    2012-12-01

    Full Text Available Microbial protein synthesis is essential to meet protein requirements in ruminants. The aim of this investigation was to evaluate the effect of incorporating extruded corn (Zea mays L. into the ration of young steers fed with grass silage on microbial protein synthesis (MPS. Twenty young steers in metabolic cages were used for supplying food. The treatments consisted of combinations of extruded corn (EC and ground corn (GC EC-10 (10% EC-30% GC; EC-25 (25% EC-15% GC and EC-40 (40% EC-0% GC. These foods constituted 40% of the ration (DM-based and the remaining 60% was grass silage. The MPS was calculated through the excretion of purine derivatives (PD in the urine, using total collection of urine. The inclusion of a higher percentage of extruded corn (EC-40 increased the PD excretion (51.85 mmol d-1, P La síntesis de proteína microbiana es fundamental para satisfacer los requerimientos proteicos en rumiantes. El objetivo de esta investigation fue evaluar el efecto de incluir maíz (Zea mays L. extruido en la ración de novillos alimentados con ensilaje de pradera, sobre la sintesis de proteina microbiana (MPS. Se emplearon 20 novillos jóvenes ubicados en jaulas metabólicas para suministro de los alimentos. Los tratamientos consistieron en combinaciones de maiz extruido (EC y maiz molido (GC EC-10 (10% EC-30% GC; EC-25 (25% EC-15% GC y EC-40 (40% EC-0% GC. Estos alimentos constituyeron el 40% de la ración (base MS y el restante 60% fue ensilaje de pradera. Se estimó la MPS a través de la excreción de derivados de purinas (PD en la orina, empleando colección total de orina. La inclusión de un mayor porcentaje de EC (EC-40 incrementó la excreción de PD (51.85 mmol d-1, P < 0,05. Los valores de excreción de PD fluctuaron entre 663 y 1078 μmol BW-075 d-1. La absorción de proteína microbiana y el flujo de N duodenal también se incrementaron por una mayor inclusión de EC (EC-40, P < 0,05. Las diferencias entre los tratamientos pueden

  4. Synthesis of hierarchical SnO{sub 2} nanoflowers with enhanced acetic acid gas sensing properties

    Energy Technology Data Exchange (ETDEWEB)

    Jin, W.X.; Ma, S.Y., E-mail: Jinwenxuan8756@163.com; Tie, Z.Z.; Li, W.Q.; Luo, J.; Cheng, L.; Xu, X.L.; Wang, T.T.; Jiang, X.H.; Mao, Y.Z.

    2015-10-30

    Highlights: • We use glycol and deionized water as solvent jointly. • Our products have good selectivity and excellent response to acetic acid. • We obtain different morphologies’ hierarchical SnO{sub 2} nanoflowers through changing the volume ratio of glycol and deionized water. - Abstract: Different morphologies hierarchical flower-like tin dioxide (SnO{sub 2}) nanostructures were fabricated by changing the volume ratio of glycol and de-ionized water (V{sub g}:V{sub w} = 0, 1:2, 1:1 and 2:1) under a template-free and low-cost hydrothermal method and subsequent calcinations. The architectures, morphologies and gas sensing performances of the products were characterized by X-ray diffraction patterns (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and gas-sensing measurement device. It can be observed that all the nanoflowers were composed of two-dimensional (2D) nanosheets, and the thickness of nanosheets is only about 9 nm when V{sub g}:V{sub w} = 1:1. The sensor based on the product of V{sub g}:V{sub w} = 1:1 exhibited excellent gas sensing performance toward 500 ppm acetic acid at 260 °C, and the response value of this sensor was about 153.6, which was above 7.5 times higher than that of ammonia (about 20.3). In addition, the 3D flower-like SnO{sub 2} nanostructures exhibited not only high response and selectivity to ppm level acetone, but also fast response and recovery time within 10 s, demonstrating it can be used as a potential candidate for detecting acetic acid. Finally, the possible formation mechanism was proposed, too.

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

    International Nuclear Information System (INIS)

    Ryzhikov, Andrey; Jońca, Justyna; Kahn, Myrtil; Fajerwerg, Katia; Chaudret, Bruno; Chapelle, Audrey; Ménini, Philippe; Shim, Chang Hyun; Gaudon, Alain; Fau, Pierre

    2015-01-01

    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 3 H 8 , and NH 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 3 H 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 3 H 8 . With NH 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 3 H 8 and NH 3

  6. 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}.

  7. 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

  8. 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.

  9. Straightforward synthesis of a triazine-based porous carbon with high gas-uptake capacities

    DEFF Research Database (Denmark)

    Hu, Xinming; Chen, Qi; Zhao, Yan Chao

    2014-01-01

    A triazine-based porous carbon material (TPC-1) was prepared directly from a fluorinated aromatic nitrile in molten zinc chloride. Trimerization of the nitrile and subsequent defluorination carbonization of the polymeric network result in the formation of TPC-1. The defluorination process......-performance porous carbon materials. This journal is...... is reversible and can etch the polymeric network to release CFn, thereby generating additional porosity and rendering TPC-1 a nitrogen-rich porous material. TPC-1 shows a high BET surface area of 1940 m2 g-1 and contains both micropores and mesopores, which facilitate the diffusion and adsorption of gas...

  10. 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)

  11. 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.

  12. Synthesis, characterization, and applications of zinc oxide nanoparticles and nanorods in acetone gas detection

    Science.gov (United States)

    Nauman Ali, Rai; Diao, Kaidi; Naz, Hina; Cui, Xudong; Xiang, Bin

    2017-09-01

    In this paper, we report an enhanced gas sensing performance of ZnO by changing the ZnO configuration from one dimension (1D) to zero dimension (0D). The structural and optical properties of the as-synthesized samples have been investigated by transmission electron microscopy (TEM), x-ray diffraction (XRD), UV-visible near infrared and photoluminescence spectroscopies (PL). TEM results confirm the non-agglomerated crystalline morphology of 0D ZnO nanoparticles as well as the 1D nanorods. All the representative peaks observed in the XRD spectrum confirm the hexagonal wurtzite structure. The UV-visible absorption and PL emission spectra for 0D ZnO nanoparticles indicate an obvious blue shift compared to the 1D nanorods because of its lower dimension size. Our dynamic response-recovery characterizations reveal that the 0D ZnO exhibits better acetone-gas sensing performance compared to 1D ZnO under an optimum operating temperature of 250 °C.

  13. 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.)

  14. Synthesis and analysis of novel polymers with high permselectivity and permeability in gas separation applications

    Energy Technology Data Exchange (ETDEWEB)

    Koros, W.J.; Paul, D.R.

    1991-12-31

    Significant progress was made toward developing advanced materials for gas separation membrane applications and rationalizing molecular structure and efficacy: Synthesized and tested polyarylates based on terephthalic or isophthalic acid or a tertiary butyl derivative of the isophthalic acid with different diols to illustrate the effects of: opening'' the matrix by incorporation of bulky packing inhibiting groups such as the tertiary butyl moiety inhibition of backbone motion via meta connected backbone connections and tightening'' of the matrix by incorporation of polar halogens. Completed high temperature characterization of sorption and transport properties for novel materials. Continued studies of the phenyl-substituted polymers aimed at producing super stable high temperature useful polymers for gas separations. Synthesized a polyarylate based on the spirobiindane diol and bibenzoyl acid chloride to incorporate long flat packable bibenzoyl units between packing disruptive spirobiindane units in an attempt to control the segmental level morphology to produce highly selective bottleneck'' regions between highly open regions.

  15. Biological conversion of synthesis gas. Final report, August 31, 1990--September 3, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Basu, R.; Klasson, K.T.; Johnson, E.R.; Takriff, M.; Clausen, E.C.; Gaddy, J.L.

    1993-09-01

    Based upon the results of this culture screening study, Rhodospirillum rubrum is recommended for biocatalysis of the water gas shift reaction and Chlorobium thiosulfatophilum is recommended for H{sub 2}S conversion to elemental sulfur. Both bacteria require tungsten light for growth and can be co-cultured together if H{sub 2}S conversion is not complete (required concentration of at least 1 ppM), thereby presenting H{sub 2} uptake by Chlorobium thiosulfatophilum. COS degradation may be accomplished by utilizing various CO-utilizing bacteria or by indirectly converting COS to elemental sulfur after the COS first undergoes reaction to H{sub 2} in water. The second alternative is probably preferred due to the low expected concentration of COS relative to H{sub 2}S. Mass transfer and kinetic studies were carried out for the Rhodospirillum rubrum and Chlorobium thiosulfatophilum bacterial systems. Rhodospirillum rubrum is a photosynthetic anaerobic bacterium which catalyzes the biological water gas shift reaction: CO + H{sub 2}O {yields} CO{sub 2} + H{sub 2}. Chlorobium thiosulfatophilum is also a photosynthetic anaerobic bacteria, and converts H{sub 2}S and COS to elemental sulfur.

  16. Catalyst and process development for synthesis gas conversion to isobutylene. Final report, September 1, 1990--January 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, R.G.; Akgerman, A.

    1994-05-06

    Previous work on isosynthesis (conversion of synthesis gas to isobutane and isobutylene) was performed at very low conversions or extreme process conditions. The objectives of this research were (1) determine the optimum process conditions for isosynthesis; (2) determine the optimum catalyst preparation method and catalyst composition/properties for isosynthesis; (3) determine the kinetics for the best catalyst; (4) develop reactor models for trickle bed, slurry, and fixed bed reactors; and (5) simulate the performance of fixed bed trickle flow reactors, slurry flow reactors, and fixed bed gas phase reactors for isosynthesis. More improvement in catalyst activity and selectivity is needed before isosynthesis can become a commercially feasible (stand-alone) process. Catalysts prepared by the precipitation method show the most promise for future development as compared with those prepared hydrothermally, by calcining zirconyl nitrate, or by a modified sol-gel method. For current catalysts the high temperatures (>673 K) required for activity also cause the production of methane (because of thermodynamics). A catalyst with higher activity at lower temperatures would magnify the unique selectivity of zirconia for isobutylene. Perhaps with a more active catalyst and acidification, oxygenate production could be limited at lower temperatures. Pressures above 50 atm cause an undesirable shift in product distribution toward heavier hydrocarbons. A model was developed that can predict carbon monoxide conversion an product distribution. The rate equation for carbon monoxide conversion contains only a rate constant and an adsorption equilibrium constant. The product distribution was predicted using a simple ratio of the rate of CO conversion. This report is divided into Introduction, Experimental, and Results and Discussion sections.

  17. Design of Gas-phase Synthesis of Core-Shell Particles by Computational Fluid - Aerosol Dynamics.

    Science.gov (United States)

    Buesser, B; Pratsinis, S E

    2011-11-01

    Core-shell particles preserve the bulk properties (e.g. magnetic, optical) of the core while its surface is modified by a shell material. Continuous aerosol coating of core TiO 2 nanoparticles with nanothin silicon dioxide shells by jet injection of hexamethyldisiloxane precursor vapor downstream of titania particle formation is elucidated by combining computational fluid and aerosol dynamics. The effect of inlet coating vapor concentration and mixing intensity on product shell thickness distribution is presented. Rapid mixing of the core aerosol with the shell precursor vapor facilitates efficient synthesis of hermetically coated core-shell nanoparticles. The predicted extent of hermetic coating shells is compared to the measured photocatalytic oxidation of isopropanol by such particles as hermetic SiO 2 shells prevent the photocatalytic activity of titania. Finally the performance of a simpler, plug-flow coating model is assessed by comparisons to the present detailed CFD model in terms of coating efficiency and silica average shell thickness and texture.

  18. Doubly fed induction machine

    Science.gov (United States)

    Skeist, S. Merrill; Baker, Richard H.

    2005-10-11

    An electro-mechanical energy conversion system coupled between an energy source and an energy load including an energy converter device having a doubly fed induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer coupled to the energy converter device to control the flow of power or energy through the doubly fed induction machine.

  19. 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......-aggregation, and subsequent massfiltering. The thesis opens with a presentation of the broader context of the research, particularly focusing on the societal importance of catalysis, followed by an introduction to the fundamentals of the science of catalysis. Three research projects are then described in individual chapters......-scale that is needed for significant global impact. This study investigates the relationship between catalytic activity for the HER and platinum catalyst loading using well-defined model systems with different loadings of mass-selected 5nm Pt nanoparticles. Using the knowledge gained on these systems, a technoeconomic...

  20. 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.

  1. Nitrogen metabolism and gas exchange parameters associated with zinc stress in tobacco expressing an ipt gene for cytokinin synthesis.

    Science.gov (United States)

    Pavlíková, Daniela; Pavlík, Milan; Procházková, Dagmar; Zemanová, Veronika; Hnilička, František; Wilhelmová, Naďa

    2014-04-15

    Increased endogenous plant cytokinin (CK) content through transformation with an isopentyl transferase (ipt) gene has been associated with improved plant stress tolerance. The impact of zinc (tested levels Zn1=250, Zn2=500, Zn3=750mgkg(-1)soil) on gas exchange parameters (net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration) and nitrogen utilization by plants resulted in changes of free amino acid concentrations (glutamic acid, glutamine, asparagine, aspartate, glycine, serine, cystein) and differed for transformed and non-transformed tobacco plants. For pot experiments, tobacco plants (Nicotiana tabacum L., cv. Wisconsin 38) transformed with a construct consisting of SAG12 promoter fused with the ipt gene for cytokinin synthesis (SAG plants) and its wild type (WT plants as a control) were used. Physiological analyses confirmed that SAG plants had improved zinc tolerance compared with the WT plants. The enhanced Zn tolerance of SAG plants was associated with the maintenance of accumulation of amino acids and with lower declines of photosynthetic and transpiration rates. In comparison to WT plants, SAG plants exposed to the highest Zn concentration accumulated lower concentrations of asparagine, which is a major metabolic product during senescence. Copyright © 2013 Elsevier GmbH. All rights reserved.

  2. 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.

  3. 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.

  4. Gas-phase synthesis of Mg-Ti nanoparticles for solid-state hydrogen storage.

    Science.gov (United States)

    Calizzi, M; Venturi, F; Ponthieu, M; Cuevas, F; Morandi, V; Perkisas, T; Bals, S; Pasquini, L

    2016-01-07

    Mg-Ti nanostructured samples with different Ti contents were prepared via compaction of nanoparticles grown by inert gas condensation with independent Mg and Ti vapour sources. The growth set-up offered the option to perform in situ hydrogen absorption before compaction. Structural and morphological characterisation was carried out by X-ray diffraction, energy dispersive spectroscopy and electron microscopy. The formation of an extended metastable solid solution of Ti in hcp Mg was detected up to 15 at% Ti in the as-grown nanoparticles, while after in situ hydrogen absorption, phase separation between MgH2 and TiH2 was observed. At a Ti content of 22 at%, a metastable Mg-Ti-H fcc phase was observed after in situ hydrogen absorption. The co-evaporation of Mg and Ti inhibited nanoparticle coalescence and crystallite growth in comparison with the evaporation of Mg only. In situ hydrogen absorption was beneficial to subsequent hydrogen behaviour, studied by high pressure differential scanning calorimetry and isothermal kinetics. A transformed fraction of 90% was reached within 100 s at 300 °C during both hydrogen absorption and desorption. The enthalpy of hydride formation was not observed to differ from bulk MgH2.

  5. Synthesis of urban greenhouse gas emission estimates from the Indianapolis Flux Experiment (INFLUX)

    Science.gov (United States)

    Turnbull, J. C.; Davis, K. J.; Deng, A.; Lauvaux, T.; Miles, N. L.; Richardson, S.; Sarmiento, D. P.; Wu, K.; Brewer, A.; Hardesty, R. M.; McKain, K.; Sweeney, C.; Gurney, K. R.; Liang, J.; O'Keeffe, D.; Patarasuk, R.; Cambaliza, M. O. L.; Harvey, R. M.; Heimburger, A. M. F.; Shepson, P. B.; Karion, A.; Lopez-Coto, I.; Prasad, K.; Whetstone, J. R.

    2016-12-01

    The Indianapolis Flux Experiment (INFLUX) is testing the boundaries of our ability to use atmospheric measurements to quantify urban greenhouse gas (GHG) emissions. The project brings together high-resolution (in both space and time) inventory assessments, a multi-year record of in situ CO2, CH4and CO from tower-based and aircraft-based atmospheric measurements along with a complementary suite of 35 trace gases and isotopes from flasks collected at the same sites, and atmospheric modelling. Together, these provide high-accuracy, high-resolution, continuous monitoring of emissions of GHGs from the city. Here we synthesize the results to date, and demonstrate broad agreement amongst city-wide emission rates determined from the various top-down and bottom-up methods. We highlight the areas where ongoing efforts are reducing uncertainties in the overall flux estimation, including accurate representation of atmospheric transport, partitioning of GHG source types and the influence of background atmospheric GHG mole fractions.

  6. 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.

  7. 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)

  8. 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.)

  9. 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.

  10. Development of an Acetate-Fed or Sugar-Fed Microbial Power Generator for Military Bases

    Science.gov (United States)

    2011-01-01

    lactate and acetate as fermentation products and is ready for test in the MFC modules. 1. Anode materials We compared the performances of acetate-fed...Sucrose • Acetate Propionate • Hydrogen gas • Lactate • Formate • !so- butyrate Unknown fbiomass -’-soluble products) KM. 80 60 I" 20 DavO

  11. Characterization of the synthesis of N,N-dimethyltryptamine by reductive amination using gas chromatography ion trap mass spectrometry.

    Science.gov (United States)

    Brandt, Simon D; Moore, Sharon A; Freeman, Sally; Kanu, Abu B

    2010-07-01

    The present study established an impurity profile of a synthetic route to the hallucinogenic N,N-dimethyltryptamine (DMT). The synthesis was carried out under reductive amination conditions between tryptamine and aqueous formaldehyde in the presence of acetic acid followed by reduction with sodium cyanoborohydride. Analytical characterization of this synthetic route was carried out by gas chromatography ion trap mass spectrometry using electron- and chemical-ionization modes. Methanol was employed as a liquid CI reagent and the impact of stoichiometric modifications on side-products formation was also investigated. Tryptamine 1, DMT 2, 2-methyltetrahydro-β-carboline (2-Me-THBC, 3), N-methyl-N-cyanomethyltryptamine (MCMT, 4), N-methyltryptamine (NMT, 5), 2-cyanomethyl-tetrahydro-β-carboline (2-CM-THBC, 6) and tetrahydro-β-carboline (THBC, 7) have been detected under a variety of conditions. Replacement of formaldehyde solution with paraformaldehyde resulted in incomplete conversion of the starting material whereas a similar replacement of sodium cyanoborohydride with sodium borohydride almost exclusively produced THBC instead of the expected DMT. Compounds 1 to 7 were quantified and the limits of detection were 28.4, 87.7, 21.5, 23.4, 41.1, 36.6, and 34.9 ng mL(-1), respectively. The limits of quantification for compounds 1 to 7 were 32.4, 88.3, 25.4, 24.6, 41.4, 39.9, and 37.0 µg mL(-1), respectively. Linearity was observed in the range of 20.8-980 µg mL(-1) with correlation coefficients > 0.99. The application holds great promise in the area of forensic chemistry where development of reliable analytical methods for the detection, identification, and quantification of DMT are crucial and also in pharmaceutical analysis where DMT might be prepared for use in human clinical studies. Copyright 2010 John Wiley & Sons, Ltd.

  12. 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.

  13. Effect of steam during Fischer–Tropsch Synthesis using biomass-derived syngas

    Science.gov (United States)

    Zi Wang; Khiet Mai; Nitin Kumar; Thomas Elder; Leslie H. Groom; James J. Spivey

    2017-01-01

    Fischer–Tropsch synthesis (FTS) with biomass- derived syngas was performed using both iron-based 100Fe/6Cu/4K/25Al catalyst and ruthenium-based 5 % Ru/SiO2 catalyst. During FTS, different concentrations of steam were co-fed with the biomass-derived syngas to promote the water gas shift reaction and increase the H2/ CO ratio...

  14. Top Value Added Chemicals From Biomass. Volume 1 - Results of Screening for Potential Candidates From Sugars and Synthesis Gas

    Science.gov (United States)

    2004-08-01

    acid Citric/Aconitic acid Lysine Gluconic acid Sorbitol Glucaric acid Ammonia synthesis , hydrogenation products Linear and branched 1º alcohols, and...primary routes to producing L-aspartic acid: 1) chemical synthesis , 2) protein extraction, 3) fermentation , and 4) enzymatic conversion. The...via fermentation routes is not likely. Chemical synthesis of this compound involves multiple steps and thus, is considered “messy” and/or difficult

  15. Gas chromatography analysis of serum cholesterol synthesis and absorption markers used to predict the efficacy of simvastatin in patients with coronary heart disease.

    Science.gov (United States)

    Wu, Wen-Feng; Wang, Qi-Hui; Zhang, Tao; Mi, Shu-Hua; Liu, Yang; Wang, Lv-Ya

    2013-08-01

    We investigated the changes in cholesterol absorption and synthesis markers before and after simvastatin therapy in Chinese patients with coronary heart disease. We developed a gas chromatography method to identify cholesterol synthesis and absorption markers and measured them in patients with coronary heart disease. We then tested their use in predicting the efficacy of simvastatin in lowering cholesterol. Serum samples from 45 patients and 38 healthy humans (controls) were analyzed in a gas chromatography-flame ionization detector. Squalene and five non-cholesterol sterols--desmosterol and lathosterol (synthesis markers) and campesterol, stigmasterol, and sitosterol (absorption markers)--were detected. The recovery rates of the markers were 95-102%. After simvastatin treatment for four weeks, the total cholesterol and low-density lipoprotein cholesterol levels had significantly decreased from the baseline values (pmarkers and can be used to predict the efficacy of simvastatin in patients with coronary heart disease. Copyright © 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  16. 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.

  17. Purge gas recovery of ammonia synthesis plant by integrated configuration of catalytic hydrogen-permselective membrane reactor and solid oxide fuel cell as a novel technology

    Science.gov (United States)

    Siavashi, Fakhteh; Saidi, Majid; Rahimpour, Mohammad Reza

    2014-12-01

    The purge gas emission of ammonia synthesis plant which contains hazardous components is one of the major sources of environmental pollution. Using integrated configuration of catalytic hydrogen-permselective membrane reactor and solid oxide fuel cell (SOFC) system is a new approach which has a great impact to reduce the pollutant emission. By application of this method, not only emission of ammonia and methane in the atmosphere is prevented, hydrogen is produced through the methane steam reforming and ammonia decomposition reactions that take place simultaneously in a catalytic membrane reactor. The pure generated hydrogen by recovery of the purge gas in the Pd-Ag membrane reactor is used as a feed of SOFC. Since water is the only byproduct of the electrochemical reaction in the SOFC, it is recycled to the reactor for providing the required water of the reforming reaction. Performance investigation of the reactor represents that the rate of hydrogen permeation increases with enhancing the reactor temperature and pressure. Also modeling results indicate that the SOFC performance improves with increasing the temperature and fuel utilization ratio. The generated power by recovery of the purging gas stream of ammonia synthesis plant in the Razi petrochemical complex is about 8 MW.

  18. 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

  19. Effect of dietary seaweed (Ulva lactuca) supplementation on growth performance of sheep and on in vitro gas production kinetics

    OpenAIRE

    EL-WAZIRY, Ahmed; AL-HAIDARY, Ahmed; OKAB, Aly; SAMARA, Emad; ABDOUN, Khalid

    2015-01-01

    This study was carried out to determine the effect of dietary seaweed (Ulva lactuca) supplementation on growth performance of sheep, in vitro gas production, estimated energy, and microbial protein synthesis. A total of 18 Naimey male sheep with average live weight of 22.78 ± 0.24 kg were randomly allocated to 3 groups. Sheep in group 1 were fed a diet containing commercial feed without seaweed as a control diet, sheep in group 2 were fed the control diet with 3% seaweed, and sheep in group 3...

  20. 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

  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

    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.

  2. Synthesis and evaluation of novel biochar-based and metal oxide-based catalysts for removal of model tar (toluene), ammonia, and hydrogen sulfide from simulated producer gas

    Science.gov (United States)

    Bhandari, Pushpak

    Gasification is a thermochemical conversion process in which carbonaceous feedstock is gasified in a controlled atmosphere to generate producer gas. The producer gas is used for production of heat, power, fuels and chemicals. Various contaminants such as tars, NH3, and H2S in producer gas possess many problems due to their corrosive nature and their ability to clog and deactivate catalysts. In this study, several catalysts were synthesized, characterized, and tested for removal of three contaminants (toluene (model tar), NH3, and H2S) from the biomass-generated producer gas. Biochar, a catalyst, was generated from gasification of switchgrass. Activated carbon and acidic surface activated carbon were synthesized using ultrasonication method from biochar. Acidic surface was synthesized by coating activated carbon with dilute acid. Mixed metal oxide catalysts were synthesized from hydrotalcite precursors using novel synthesis technique using microwave and ultrasonication. Surface area of activated carbon (˜900 m2/g) was significantly higher than that of its precursor biochar (˜60 m2/g). Surface area of metal oxide catalyst was approximately 180 m2/g after calcination. Biochar, activated carbon, and acidic surface activated carbon showed toluene removal efficiencies of approximately 78, 88, and 88 %, respectively, when the catalysts were tested individually with toluene in the presence of producer gas at 800 °C. The toluene removal efficiencies increased to 86, 91, and 97 % using biochar, activated carbon and acidic surface activated carbon, respectively in the presence of NH3 and H2S in the producer gas. Increase in toluene removal efficiencies in presence of NH3 and H2S indicates that NH3 and H 2S play a role in toluene reforming reactions during simultaneous removal of contaminants. Toluene removal efficiency for mixed metal oxide was approximately 83%. Ammonia adsorption capacities were 0.008 g NH3/g catalyst for biochar and 0.03g NH3/g catalyst for activated

  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. 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.

  7. Synthesis of Uniform Rare Earth Doped Gd2O2S Sub-micron Sized Spheres Using Gas-Aided Sulfurization and their Optical Characteristics.

    Science.gov (United States)

    He, Shuqing; Zhao, Xinyu; Tan, Mei Chee

    2017-01-01

    In this work, we report a detailed study of the synthesis of sub-micron sized Gd 2 O 2 S spheres using a two-step process: (1) amorphous precursor synthesis using the solvothermal method where a surfactant was used to control particle morphology, followed by (2) crystallization to form Gd 2 O 2 S polycrystalline spheres in a sulfur-rich environment. The crystallization and sulfurization processes are investigated by monitoring the crystal growth at different temperatures and under different environments using mainly x-ray diffraction and analysis of the precursor's thermal decomposition profile. The optical emissions of the Er and Yb-Er doped Gd 2 O 2 S upon excitation at 975 nm were investigated to identify the optimal dopant concentrations, optimal heat treatment temperature as well as to further elucidate any fine structure changes. Our results also show that the maximum emission intensities were obtained for a heat treatment temperature of 800 °C, where increased dopant diffusion coupled with non-uniform surface segregation at much higher temperatures led to non-uniform dopant distribution and reduced emission intensities. Our findings from these studies would be useful towards the synthesis of brightly-emitting Gd 2 O 2 S based luminescent materials as well as for the controlled gas-aided sulfurization of other metal oxysulfides.

  8. Gas-phase synthesis of the rare-gas carbene cation ArCH2+ using doubly ionised bromomethane as a superelectrophilic reagent

    Czech Academy of Sciences Publication Activity Database

    Ascenzi, D.; Tosi, P.; Roithová, Jana; Schröder, Detlef

    -, č. 34 (2008), s. 4055-4057 ISSN 1359-7345 Institutional research plan: CEZ:AV0Z40550506 Keywords : argon * dications * mass spectrometry * rare-gas compounds * superelectrophiles Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.340, year: 2008

  9. The effect of synthesis gas composition on the Fischer-Tropsch synthesis over Co/{gamma}-Al{sub 2}O{sub 3} and Co-Re/{gamma}-Al{sub 2}O{sub 3} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Tristantini, Dewi; Gevert, Boerje [Chalmers University of Technology, Department of Chemical and Biological Engineering, S-412 96 Gothenburg (Sweden); Loegdberg, Sara [Royal Institute of Technology (KTH), Chemical Technology, S-100 44 Stockholm (Sweden); Borg, Oeyvind; Holmen, Anders [Norwegian University of Science and Technology (NTNU), Department of Chemical Engineering, N-7491 Trondheim (Norway)

    2007-07-15

    The Fischer-Tropsch synthesis over Co/{gamma}-Al{sub 2}O{sub 3} and Co-Re/{gamma}-Al{sub 2}O{sub 3} was investigated in a fixed-bed reactor at 20 bar and 483 K using feed gases with molar H{sub 2}/CO ratios of 2.1, 1.5 and 1.0 simulating synthesis gas derived from biomass. With lower H{sub 2}/CO ratios in the feed, the CO conversion and the CH{sub 4} selectivity decreased, while the C{sub 5+} selectivity and olefin/paraffin ratio for C{sub 2}-C{sub 4} increased slightly. The water-gas shift activity was low for both catalysts, resulting in high molar usage ratios of H{sub 2}/CO (close to 2.0), even at the lower inlet ratios (i.e. 1.5 and 1.0). For both catalysts, the drop in the production rate of hydrocarbons when shifting from an inlet ratio of 2.1 to 1.5 was significant mainly because the H{sub 2}/CO usage ratio did not follow the change in the inlet ratio. The hydrocarbon selectivities were rather similar for inlet H{sub 2}/CO ratios of 2.1 and 1.5, while significantly deviating from those for an inlet ratio of 1.0. With the studied catalysts, it is possible to utilize the advantages of an inlet ratio of 1.0 (higher selectivity to C{sub 5+}, lower selectivity to CH{sub 4}, no water-gas shifting of the bio-syngas needed prior to the FT reactor) if a low syngas conversion is accepted. (author)

  10. 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.

  11. 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.

  12. Hydrothermal synthesis of hierarchical flower-like ZnO nanostructure and its enhanced ethanol gas-sensing properties

    Science.gov (United States)

    Zhu, Ling; Li, Yanqiong; Zeng, Wen

    2018-01-01

    ZnO nanoparticles, nanoplates and nanoflowers have been successfully synthesized via a facile hydrothermal route, and their microstructures and gas-sensing properties to ethanol were investigated. Among all the nanostructures, the nanoplates-assembled nanoflowers exhibited significantly higher gas-sensing performances than the others, which may ascribe to their hierarchical architectures with large specific area and abundant spaces for gas diffusion. Furthermore, we surprisingly found that the concentration of surfactant CTAB used had an essential effect on the ultimate morphology of the hierarchical nanoflowers. We hoped our findings could be in favor of further investigations on the fabrication of perfect hierarchical architectures.

  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. 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

  15. 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)

  16. 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%.

  17. Gas-Phase Synthesis of Dimethyl Carbonate from Methanol and Carbon Dioxide Over Co1.5PW12O40 Keggin-Type Heteropolyanion

    Directory of Open Access Journals (Sweden)

    Ahmed Aouissi

    2010-03-01

    Full Text Available The reactivity of Co1.5PW12O40 in the direct synthesis of dimethyl carbonate (DMC from CO2 and CH3OH was investigated. The synthesized catalyst has been characterized by means of FTIR, XRD, TG, and DTA and tested in gas phase under atmospheric pressure. The effects of the reaction temperature, time on stream, and methanol weight hourly space velocity (MWHSV on the conversion and DMC selectivity were investigated. The highest conversion (7.6% and highest DMC selectivity (86.5% were obtained at the lowest temperature used (200 °C. Increasing the space velocity MWHSV increased the selectivity of DMC, but decreased the conversion. A gain of 18.4% of DMC selectivity was obtained when the MWHSV was increased from 0.65 h-1 to 3.2 h-1.

  18. Synthesis of CuNi/C and CuNi/γ-Al2O3 Catalysts for the Reverse Water Gas Shift Reaction

    Directory of Open Access Journals (Sweden)

    Maxime Lortie

    2015-01-01

    Full Text Available A new polyol synthesis method is described in which CuNi nanoparticles of different Cu/Ni atomic ratios were supported on both carbon and gamma-alumina and compared with Pt catalysts using the reverse water gas shift, RWGS, reaction. All catalysts were highly selective for CO formation. The concentration of CH4 was less than the detection limit. Cu was the most abundant metal on the CuNi alloy surfaces, as determined by X-ray photoelectron spectroscopy, XPS, measurements. Only one CuNi alloy catalyst, Cu50Ni50/C, appeared to be as thermally stable as the Pt/C catalysts. After three temperature cycles, from 400 to 700°C, the CO yield at 700°C obtained using the Cu50Ni50/C catalyst was comparable to that obtained using a Pt/C catalyst.

  19. Simultaneous amination of TiO{sub 2} nanoparticles in the gas phase synthesis for bio-medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyoung-No; Lee, Jai-Sung [Department of Metallurgy and Materials Science, Hanyang University-ERICA, Ansan 426-791 (Korea, Republic of); Kim, Yangeon; Lee, Chang-Woo, E-mail: jslee@hanyang.ac.kr [Battelle-Korea Laboratory, International Center for Converging Technology (Rm401) Korea University, Seoul 136-713 (Korea, Republic of)

    2011-10-29

    A simultaneous synthesis and surface amination method to effectively modify the surface of inorganic nanoparticles is discussed in this study. As a target material system and surface functional group, TiO{sub 2} nanoparticles and amine were selected. APTES (3-aminopropyltriethoxysilane), the source of amine group, was mixed with TTIP (titanium tetraisopropoxide) and used for the synthesis of aminated TiO{sub 2} nanoparticles. XRD (X-ray diffractometry) results showed TiO{sub 2} nanoparticles of pure anatase phase, 15 nm in crystallite size, were successfully synthesized at 700deg. C and 50 mbar. Fourier transformation infrared (FT-IR) spectroscopy measurement and confocal microscopy study using fluoresceine isothiocyanate (FITC) confirmed that amine groups were successfully deposited and activated on the surface of TiO{sub 2} nanoparticles.

  20. 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.

  1. 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.

  2. A facile and green approach for the controlled synthesis of porous SnO₂ nanospheres: application as an efficient photocatalyst and an excellent gas sensing material.

    Science.gov (United States)

    Manjula, P; Boppella, Ramireddy; Manorama, Sunkara V

    2012-11-01

    A facile and elegant methodology invoking the principles of Green Chemistry for the synthesis of porous tin dioxide nanospheres has been described. The low-temperature (∼50 °C) synthesis of SnO₂ nanoparticles and their self-assembly into organized, uniform, and monodispersed porous nanospheres with high surface area is facilitated by controlling the concentration of glucose, which acts as a stabilizing as well as structure-directing agent. A systematic control on the stannate to glucose molar concentration ratio determines the exact conditions to obtain monodispersed nanospheres, preferentially over random aggregation. Detailed characterization of the structure, morphology, and chemical composition reveals that the synthesized material, 50 nm SnO₂ porous nanospheres possess BET surface area of about 160 m²/g. Each porous nanosphere consists of a few hundred nanoparticles ∼2-3 nm in diameter with tetragonal cassiterite crystal structure. The SnO₂ nanospheres exhibit elevated photocatalytic activity toward methyl orange with good recyclability. Because of the high activity and stability of this photocatalyst, the material is ideal for applications in environmental remediation. Moreover, SnO₂ nanospheres display excellent gas sensing capabilities toward hydrogen. Surface modification of the nanospheres with Pd transforms this sensing material into a highly sensitive and selective room-temperature hydrogen sensor.

  3. 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.

  4. Synthesis and characterization of activated carbon materials for natural gas storage; Sintese e caracterizacao de materiais carbonosos ativados para armazenamento de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Coutinho, A.R.; Mendez, M.O.; Capobianco, G. [MULTIVACUO Industria e Comercio de Filtros Ltda., Campinas, SP (Brazil); Otani, C.; Petraconi, G.; Maciel, H.; Massi, M.; Urruchi, W. [Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP (Brazil). Inst. Tecnologico de Aeronautica; Campos, F.B. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES); Campos, M.F.; Furin, R. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The activated carbon (AC) materials are characterized by a highly porous structure and high specific surface area, giving the capacity to adsorb molecules in liquid and gaseous phase. The present work has the objectives: project and construction of a pilot plant for production of 30 kg/month of AC; development of hybrid process of AC production using physical and/or chemical activation and cold plasma. The biomass raw materials are used, like pinnus wood and macadamia shell. The samples are prepared in form of grains or briquettes, and inserted in reactor inside of the furnace for the pre-activation process. This process is realized in temperatures of 600 deg C - 900 deg C, with heating rates of 1 deg C.min{sup -1} - 10 deg C.min{sup -1}, using different flow rate of inert gas (200 ml.min{sup -1} - 1000 ml.min{sup -1}); with two kinds of a activating agent: steam and CO{sub 2}. After the withdrawal of the samples of the reactor, the samples are submitted to the final process of activation, in oxidant plasma reactor, varying the following process parameters: pressure, gas flow rate, power and residence time. The chemical activation process consists of adding to the raw material the activating agents, as ZnCl{sub 2}, KOH, and others, in varied ratios. The AC had been characterized by: scanning electronic microscopy (SEM), specific surface area (SSA) by the BET and DR techniques. The preliminary results presents AC produced by the chemical activation with a SSA of 1700 m{sup 2}.g{sup -1} and pore volume of 0,8 cm{sup 3}.g{sup -1}, with average pore diameter of 2,0 nm and burn-off degree of 50%. The AC prepared by plasma process shown values of SSA up to 3200 m{sup 2}.g{sup -1}. (Project supported by Rede Gas Energia - PETROBRAS TC 540.4.049.03-0). (author)

  5. 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.

  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. Synthesis of Nanocrystalline SnO2 Modified TiO2:a Material for Carbon Monoxide Gas Sensor

    OpenAIRE

    A. B. BODADE; M. ALVI; A. V.KADU; S. V.JAGTAP; S. K. RITHE; P. R. PADOLE; G. N. CHAUDHARI

    2008-01-01

    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....

  8. Controlled synthesis of Ni-doped ZnO hexagonal microdiscs and their gas sensing properties at low temperature

    Science.gov (United States)

    Ganesh, R. Sankar; Durgadevi, E.; Navaneethan, M.; Patil, V. L.; Ponnusamy, S.; Muthamizhchelvan, C.; Kawasaki, S.; Patil, P. S.; Hayakawa, Y.

    2017-12-01

    High sensitivity ammonia (NH3) gas sensor based on nickel-doped ZnO (NZO) hexagonal microdisc like-nanostructures is reported in this work. Field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) revealed that the undoped ZnO revealed interconnected hexagonal microdiscs transformed into hollow square shaped interconnected hexagonal microdiscs. NZO (6 wt%) showed higher response compared with other wt% and exhibited highest response of 15.1 when exposed to 100 ppm concentration of ammonia (NH3) gas at 150 °C. NZO (6 wt%) possessed good response time of 5.5 s at 100 ppm.

  9. 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

  10. Gasification of coal-derived chars in synthesis gas mixtures under intraparticle mass-transfer-controlled conditions

    NARCIS (Netherlands)

    Bliek, A.; Lont, J.C.; van Swaaij, Willibrordus Petrus Maria

    1986-01-01

    A model has been formulated to describe the quasi-steady-state gasification of coal-derived chars in gas mixtures where both the reactants carbon dioxide and steam, and the gasification products carbon monoxide and hydrogen are present. As such, these conditions reflect the situation found in most

  11. 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.

  12. 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.

  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. Localized Liquid-Phase Synthesis of Porous SnO2Nanotubes on MEMS Platform for Low-Power, High Performance Gas Sensors.

    Science.gov (United States)

    Cho, Incheol; Kang, Kyungnam; Yang, Daejong; Yun, Jeonghoon; Park, Inkyu

    2017-08-16

    We have developed highly sensitive, low-power gas sensors through the novel integration method of porous SnO 2 nanotubes (NTs) on a micro-electro-mechanical-systems (MEMS) platform. As a template material, ZnO nanowires (NWs) were directly synthesized on beam-shaped, suspended microheaters through an in situ localized hydrothermal reaction induced by local thermal energy around the Joule-heated area. Also, the liquid-phase deposition process enabled the formation of a porous SnO 2 thin film on the surface of ZnO NWs and simultaneous etching of the ZnO core, eventually to generate porous SnO 2 NTs. Because of the localized synthesis of SnO 2 NTs on the suspended microheater, very low power for the gas sensor operation (<6 mW) has been realized. Moreover, the sensing performance (e.g., sensitivity and response time) of synthesized SnO 2 NTs was dramatically enhanced compared to that of ZnO NWs. In addition, the sensing performance was further improved by forming SnO 2 -ZnO hybrid nanostructures due to the heterojunction effect.

  15. 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.

  16. Short communication: Effect of antioxidant supplementation on milk production, milk fat synthesis, and milk fatty acids in dairy cows when fed a diet designed to cause milk fat depression.

    Science.gov (United States)

    Boerman, J P; Preseault, C L; Kraft, J; Dann, H M; Lock, A L

    2014-02-01

    This study evaluated the effect of a blend of synthetic antioxidants on the yield of milk and milk components and milk fatty acid composition in dairy cows fed a diet designed to cause milk fat depression (MFD). We hypothesized that supplementing a synthetic antioxidant to diets with a high rumen unsaturated fatty acid load (RUFAL) would decrease the severity of MFD. Sixteen lactating Holstein cows (163 ± 47 d in milk), in a crossover design with two 21-d periods, were fed a corn silage and grass silage-based diet containing 15% distillers grains. The diet contained 34% neutral detergent fiber, 18% crude protein, 26% starch, and 4.3% total fatty acids (dry matter basis). Cows were fed the diet without supplementation (control; CON) or supplemented with 0.02% (dry matter basis) of a synthetic antioxidant (AOX; Agrado Plus, Novus International Inc., St. Charles, MO). Dry matter intake and milk yields were recorded daily. Milk samples were collected at the start of the study for baseline values and the end of each period (d 20-21) and analyzed for milk components and fatty acid composition. Dry matter intake and milk yield were unaffected by treatment and averaged 25.9 and 50.2 kg/d, respectively. Similarly, we observed no effect of treatment on yields of fat, protein, lactose, 3.5% fat-corrected milk, energy-corrected milk, feed efficiency, body weight, or body condition score. Milk fat concentration and yield were both reduced by the high RUFAL diets. We observed a tendency for AOX to increase the concentration of milk fat and decrease the concentration of milk protein. Yields of de novo and preformed fatty acids were not affected by treatment, although we detected a trend for a slight increase in the yield of 16-carbon fatty acid for AOX compared with CON. Treatment had only minor effects on individual milk fatty acids, except for the concentration and yield of linoleic acid, which were over 90% higher for AOX compared with CON. In conclusion, milk fat

  17. RUMEN MICROBIAL GROWTH IN SHEEP FED THREE DISTINCT QUALITY HAYS

    Directory of Open Access Journals (Sweden)

    Ives Cláudio da Silva Bueno

    2009-10-01

    Full Text Available Forages usually fed to sheep in tropics have low values of crude protein (CP content and/or low availability of protein. The aim of this work was to identify different profiles of microbial protein (MP yield for sheep fed hays with distinct CP levels. Three hays (LUC - Lucerne, SIG - signalgrass and TIF - Tifton-85, six animals (Santa Inês wethers fitted with rumen and duodenum cannulas placed in a double Latin square were used to evaluate transit rates of microbial protein and in vivo microbial synthesis. In vitro microbial protein synthesis was evaluated in a complete factorial statistical design. The parameters studied were rumen pH and ammonia-N, microbial protein transit using 15N as marker and microbial protein synthesis by in vivo (purine derivatives urinary excretion and in vitro (32P incorporation techniques. Rumen pH values did not present significant differences for treatments (hays and these values were in a level considered as satisfactory to good microbial development. As studied hays presented great variations on CP levels, the concentration of ammonia-N was higher for animals fed LUC (191 g CP/kg DM and lower for animals fed SIG (29 g/kg DM, therefore presented no difference for ammonia-N concentration (P > 0.05 between SIG and TIF (75 g CP/kg DM. The nitrogen assimilation rate (k1 by rumen microorganisms was much faster (P 0.05. Feeds with low proteic content had prejudicial effect on utilization of nutrients by sheep and on maintenance of a healthy rumen environment. This fact was highlighted by variations on rumen ammonia-N concentrations. The microbial synthesis capacity was identified more efficiently by purine derivatives urinary excretion technique. The in vitro technique of 32P incorporation did not distinguish microbial growths from tested feeds degradation. In vitro technique showed strong dependency of inoculum quality.

  18. 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.

  19. Synthesis and characterization of Cu-doped TiO2 thin films produced by the inert gas condensation technique

    Science.gov (United States)

    Ahmed, H. A.; Abu-Eishah, S. I.; Ayesh, A. I.; Mahmoud, S. T.

    2017-07-01

    The bandgap of thin films Cu-doped TiO2 nanoclusters prepared using the inert gas condensation (IGC) technique have been investigated at various Cu contents. The samples were characterized using XRD, SEM/EDS and UV-visible spectrophotometer. It was found that doping of TiO2 thin film nanoclusters with Cu enhance its optical activity and shift it to the visible region; which makes it useful in photocatalytic applications.

  20. 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

  1. 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.

  2. 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

    2018-04-16

    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 BET surface area of 1604 m2 g-1, outstanding CO2, H2 and CH4 storage capacities, as well as good adsorption selectivities for the separation of CO2/N2 and CO2/CH4 gas pairs. The CO2 uptake reached values 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 CO2/N2), 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.

  3. 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)

  4. 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.

  5. 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)

  6. 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.

  7. Synthesis of trapezohedral indium oxide nanoparticles with high-index {211} facets and high gas sensing activity.

    Science.gov (United States)

    Han, Xiguang; Han, Xiao; Sun, Linqiang; Gao, Shengguang; Li, Liang; Kuang, Qin; Xie, Zhaoxiong; Wang, Chao

    2015-06-14

    Nanocrystals with high-index facets usually exhibit higher catalytic activities than those with only low-index facets. Trapezohedron-shaped (TS) In2O3 particles with exposed high-index {211} facets were successfully synthesized in an oleic acid (OA) and trioctylamine (TOA) system. It has been demonstrated that the gas sensing activity of TS In2O3 particles with exposed high-index {211} facets is higher than that of octahedron-shaped In2O3 particles with exposed low-index {111} facets.

  8. 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.

  9. Synthesis of Ag doped SnO2 thin films for the evaluation of H2S gas sensing properties

    Science.gov (United States)

    Kolhe, Pankaj S.; Koinkar, Pankaj M.; Maiti, Namita; Sonawane, Kishor M.

    2017-11-01

    The Tin Oxide (SnO2) based thin films doped with 1.5, 3.0 and 4.5 mol% of Ag were deposited on the glass substrates using the advanced chemical spray pyrolysis technique. All the films were deposited at temperature 400 °C. The crystalline structure of the samples was analyzed by X-ray diffraction (XRD). All the XRD patterns of the films showed a well-defined polycrystalline phase, fitting well with the SnO2 tetragonal rutile type structure. The optical properties of the Ag doped SnO2 films were studied using UV-Visible absorption spectroscopy. The surface morphological analysis of as-synthesized Ag doped SnO2 films have been carried out using scanning electron microscope (SEM). The sensor response was estimated by the change in the electrical resistance of the film in the absence and presence of H2S gas. The sensor response and sensitivity in relation to, operation temperature and the gas concentration have been systematically studied. A significant response (∼ 1.38) and with a short response and recovery time (46 s, 110 s) towards 450 ppm H2S at 100 °C operating temperature is observed for the 3 mol% Ag-doped SnO2 film. This method offers a highly promising candidate for development of materials sensors due to facile fabrication route and desirable sensing performance.

  10. 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.

  11. Facile synthesis of α-Fe2O3 nanoparticles for high-performance CO gas sensor

    International Nuclear Information System (INIS)

    Cuong, Nguyen Duc; Khieu, Dinh Quang; Hoa, Tran Thai; Quang, Duong Tuan; Viet, Pham Hung; Lam, Tran Dai; Hoa, Nguyen Duc; Hieu, Nguyen Van

    2015-01-01

    Highlights: • We have demonstrated a facile method to prepare Fe 2 O 3 nanoparticles. • The gas sensing properties of α-Fe 2 O 3 have been invested. • The results show potential application of α-Fe 2 O 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 2 O 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 2 O 3 particles had a peanut-like geometry with hemispherical ends. The response of the α-Fe 2 O 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 2 O 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 2 O 3 NPs as a good sensing material in the fabrication of CO sensor

  12. Carbon Nitride Decorated Ball-Flower like Co3O4 Hybrid Composite: Hydrothermal Synthesis and Ethanol Gas Sensing Application

    Directory of Open Access Journals (Sweden)

    Yuxiao Gong

    2018-02-01

    Full Text Available Recently, semiconducting metal oxide (SMO gas sensors have attracted the attention of researchers for high conductivity, labile features by environment, low cost, easy preparation, etc. However, traditional SMOs have some defects such as higher operating temperature and lower response value, which greatly limit their application in the field of gas sensor. In this work, the carbon nitride decorated ball-flower like Co3O4 composite was successfully synthesized via a facile hydrothermal method, the composition and morphology of the as-synthesized samples were studied by the techniques of X-ray powder diffraction (XRD, Field-emission scanning electron microscopy (FESEM, Transmission electron microscopy (TEM, Fourier transform infrared spectrometer (FT-IR and N2-sorption. As a consequence, the pure Co3O4 and the carbon nitride decorated Co3O4 both possess ball-flower like structure, and the as-synthesized carbon nitride decorated Co3O4 composite exhibits significant sensing properties to ethanol which is 1.6 times higher than that of pure Co3O4, furthermore, the composite possesses high selectivity and stability towards ethanol detection.

  13. Synthesis and analysis of novel polymers with high permselectivity and permeability in gas separation applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Koros, W.J.; Paul, D.R.

    1995-05-01

    During the three years of support under this grant, ten novel polymer structures have been synthesized and characterized in detail in terms of sorption and transport properties to test the hypotheses on strategies to develop advanced materials for gas separation membranes. The extremely important O{sub 2}/N{sub 2} and CO{sub 2}/CH{sub 4} systems have been the focus of this work. Data for permeabilities and permselectivities for O{sub 2}/N{sub 2} and CO{sub 2}/CH{sub 4} at 35 C at approximately 2 atm feed pressure for O{sub 2} and N{sub 2} and 10 atm for CO{sub 2} and CH{sub 4} are reported in two tables and will be discussed in two parts, one related to each of the groups of structures in these two tables. For the sake of efficiency, the author will only consider the O{sub 2}/N{sub 2} data; however, similar trends apply for the CO{sub 2}/CH{sub 4} system as well. This gas pair is useful, since solubility selectivity effects are generally of much smaller importance than for the CO{sub 2}/CH{sub 4} pair, so even without detailed solubility and diffusivity data, mobility selectivity based arguments tend to be adequate.

  14. 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

  15. 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.

  16. 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.

  17. 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.

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

    Science.gov (United States)

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

    2016-05-27

    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 analysis. The core-shell structure, which is composed of an Fe core surrounded by a maghemite (γ-Fe2O3) and/or magnetite (Fe3O4) shell, was confirmed by fast Fourier transform (FFT) analysis combined with EELS. It was found that the particle size and shape strongly depend on the gas environment. Moreover, extensive analysis showed that NPs with a size between 10-20 nm possess a truncated cubic morphology, which is confined by the 6 {100} planes that are truncated by the 12 {110} planes at different degrees. For NPs larger than 20 nm, the rhombic dodecahedron defined by the 12 {110} planes is the predominant crystal shape, while truncated rhombic dodecahedrons, as well as non-truncated and truncated cubic NPs, were also observed. The NPs without truncation showed a characteristic inward relaxation indicating that besides thermodynamics kinetics also plays a crucial role during particle growth.

  19. 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

  20. De novo synthesis of a metal-organic framework material featuring ultrahigh surface area and gas storage capacities.

    Science.gov (United States)

    Farha, Omar K; Yazaydın, A Özgür; Eryazici, Ibrahim; Malliakas, Christos D; Hauser, Brad G; Kanatzidis, Mercouri G; Nguyen, SonBinh T; Snurr, Randall Q; Hupp, Joseph T

    2010-11-01

    Metal-organic frameworks--a class of porous hybrid materials built from metal ions and organic bridges--have recently shown great promise for a wide variety of applications. The large choice of building blocks means that the structures and pore characteristics of the metal-organic frameworks can be tuned relatively easily. However, despite much research, it remains challenging to prepare frameworks specifically tailored for particular applications. Here, we have used computational modelling to design and predictively characterize a metal-organic framework (NU-100) with a particularly high surface area. Subsequent experimental synthesis yielded a material, matching the calculated structure, with a high BET surface area (6,143 m(2) g(-1)). Furthermore, sorption measurements revealed that the material had high storage capacities for hydrogen (164 mg g(-1)) and carbon dioxide (2,315 mg g(-1))--gases of high importance in the contexts of clean energy and climate alteration, respectively--in excellent agreement with predictions from modelling.

  1. 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

    2011-08-01

    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.

  2. Serotonin syndrome in a breast-fed neonate.

    Science.gov (United States)

    Morris, Rachel; Matthes, Jean

    2015-05-06

    A late preterm presented with tachypnoea, jitteriness, irritability and low grade fever. Blood gas showed a compensated metabolic acidosis. His mother was taking the selective serotonin reuptake inhibitor (SSRI) fluoxetine, 60 mg/day, and he was exclusively breast-fed. The baby's serum level of fluoxetine on day 8 was within the adult therapeutic range and his symptoms were ascribed to fluoxetine toxicity. On changing to formula feeds, his symptoms resolved. SSRIs are commonly administered during pregnancy, but SSRI toxicity in infants is rarely reported. It is possible that this condition is under diagnosed or, alternatively, misdiagnosed as SSRI withdrawal in breast fed infants whose mothers are on SSRIs. There is limited research looking at serotonin excess in neonates, making case reports such as this important in our learning. Increased awareness may prompt more frequent measurements of blood levels in breast-fed infants whose mothers are on SSRIs. 2015 BMJ Publishing Group Ltd.

  3. 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)

  4. GAS PHASE SYNTHESIS OF (ISO)QUINOLINE AND ITS ROLE IN THE FORMATION OF NUCLEOBASES IN THE INTERSTELLAR MEDIUM

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Dorian S. N.; Kaiser, Ralf I. [Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Kostko, Oleg; Troy, Tyler P.; Ahmed, Musahid [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Mebel, Alexander M. [Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199 (United States); Tielens, Alexander G. G. M. [Leiden Observatory, University of Leiden, Leiden (Netherlands)

    2015-04-20

    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.

  5. 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)

  6. 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)

  7. Synthesis and microwave modification of CuO nanoparticles: crystallinity and morphological variations, catalysis, and gas sensing.

    Science.gov (United States)

    Yang, Chao; Xiao, Feng; Wang, Jide; Su, Xintai

    2014-12-01

    CuO nanoparticles with different morphologies were synthesized by chemical precipitation and subsequently modified by microwave hydrothermal processing. The nanoparticles were precipitated by the introduction of a strong base to an aqueous solution of copper cations in the presence/absence of the polyethylene glycol and urea additives. The modification of the nanoparticles was subsequently carried out by a microwave hydrothermal treatment of suspensions of the precipitates, precipitated with and without the additives. X-ray powder diffraction analysis indicated that the crystallinity and crystallite size of the CuO nanoparticles increased after the microwave hydrothermal modification. Microscopy observations revealed the morphology changes induced by microwave hydrothermal processing. The thermal decomposition of ammonium perchlorate and the detection of volatile gases were performed to evaluate the catalytic and gas sensing properties of the synthesized CuO nanoparticles. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Combined plasma gas-phase synthesis and colloidal processing of InP/ZnS core/shell nanocrystals

    Directory of Open Access Journals (Sweden)

    Hue Ryan

    2011-01-01

    Full Text Available 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 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.

  9. 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.

  10. 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.

  11. Gas phase studies of the Pesci decarboxylation reaction: synthesis, structure, and unimolecular and bimolecular reactivity of organometallic ions.

    Science.gov (United States)

    O'Hair, Richard A J; Rijs, Nicole J

    2015-02-17

    CONSPECTUS: Decarboxylation chemistry has a rich history, and in more recent times, it has been recruited in the quest to develop cheaper, cleaner, and more efficient bond-coupling reactions. Thus, over the past two decades, there has been intense investigation into new metal-catalyzed reactions of carboxylic substrates. Understanding the elementary steps of metal-mediated transformations is at the heart of inventing new reactions and improving the performance of existing ones. Fortunately, during the same time period, there has been a convergence in mass spectrometry (MS) techniques, which allows these catalytic processes to be examined efficiently in the gas phase. Thus, electrospray ionization (ESI) sources have been combined with ion-trap mass spectrometers, which in turn have been modified to either accept radiation from tunable OPO lasers for spectroscopy based structural assignment of ions or to allow the study of ion-molecule reactions (IMR). The resultant "complete" gas-phase chemical laboratories provide a platform to study the elementary steps of metal-catalyzed decarboxylation reactions in exquisite detail. In this Account, we illustrate how the powerful combination of ion trap mass spectrometry experiments and DFT calculations can be systematically used to examine the formation of organometallic ions and their chemical transformations. Specifically, ESI-MS allows the transfer of inorganic carboxylate complexes, [RCO2M(L)n](x), (x = charge) from the condensed to the gas phase. These mass selected ions serve as precursors to organometallic ions [RM(L)n](x) via neutral extrusion of CO2, accessible by slow heating in the ion trap using collision induced dissociation (CID). This approach provides access to an array of organometallic ions with well-defined stoichiometry. In terms of understanding the decarboxylation process, we highlight the role of the metal center (M), the organic group (R), and the auxiliary ligand (L), along with cluster nuclearity, in

  12. Converter fed sub sea motor drives

    Energy Technology Data Exchange (ETDEWEB)

    Raad, R.O.

    1995-09-01

    Minor offshore gas and oil resources located 20-50 km from existing installations may often be commercially exploited only by use of complete sub sea solutions. This thesis deals with analyses of a sub sea adjustable speed electric motor which is fed by a frequency converter via a long cable (up to 50 km) between the converter and the motor. The author develops a general model for analysing such motor drive systems with the objective of verifying the feasibility of specific applications and of specifying the requirements on the system components. The simulation model is used to identify the critical frequency ranges in which the converter must not generate significant harmonics, to verify the start-up strategy chosen, and to verify the stability with potential disturbances applied to the system. Simulation models are developed for both transient and steady state analyses. They are accurate up to 5 kHz and can incorporate the frequency dependency of the motor and cable parameters. Ideal thyristors and diodes are used. The models are implemented in existing simulation tools. Most of the results relate to a base case with a 670 kW squirrel cage motor fed from a 30 km long cable, but cases with 3 MW rating or with 50 km cable have also been analyzed and found to be feasible. Each specific application must be separately studied. Results of simulation calculations are presented and conclusions given. 53 refs., 124 figs., 23 tabs.

  13. Effects of Replacing Dry-rolled Corn with Increasing Levels of Corn Dried Distillers Grains with Solubles on Characteristics of Digestion, Microbial Protein Synthesis and Digestible Energy of Diet in Hair Lambs Fed High-concentrate Diets.

    Science.gov (United States)

    Castro-Pérez, B I; Garzón-Proaño, J S; López-Soto, M A; Barreras, A; González, V M; Plascencia, A; Estrada-Angulo, A; Dávila-Ramos, H; Ríos-Rincón, F G; Zinn, R A

    2013-08-01

    Four male lambs (Katahdin; average live weight 25.9±2.9 kg) with "T" type cannulas in the rumen and proximal duodenum were used in a 4×4 Latin square experiment to evaluate the influence of supplemental dry distillers grain with solubles (DDGS) levels (0, 10, 20 and 30%, dry matter basis) in substitution for dry-rolled (DR) corn on characteristics of digestive function and digestible energy (DE) of diet. Treatments did not influence ruminal pH. Substitution of DR corn with DDGS increased ruminal neutral detergent fiber (NDF) digestion (quadratic effect, p<0.01), but decreased ruminal organic matter (OM) digestion (linear effect, p<0.01). Replacing corn with DDGS increased (linear, p≤0.02) duodenal flow of lipids, NDF and feed N. But there were no treatment effects on flow to the small intestine of microbial nitrogen (MN) or microbial N efficiency. The estimated UIP value of DDGS was 44%. Postruminal digestion of OM, starch, lipids and nitrogen (N) were not affected by treatments. Total tract digestion of N increased (linear, p = 0.04) as the DDGS level increased, but DDGS substitution tended to decrease total tract digestion of OM (p = 0.06) and digestion of gross energy (p = 0.08). However, it did not affect the dietary digestible energy (DE, MJ/kg), reflecting the greater gross energy content of DDGS versus DR corn in the replacements. The comparative DE value of DDGS may be considered similar to the DE value of the DR corn it replaced up to 30% in the finishing diets fed to lambs.

  14. Effects of Replacing Dry-rolled Corn with Increasing Levels of Corn Dried Distillers Grains with Solubles on Characteristics of Digestion, Microbial Protein Synthesis and Digestible Energy of Diet in Hair Lambs Fed High-concentrate Diets

    Directory of Open Access Journals (Sweden)

    B. I. Castro-Pérez

    2013-08-01

    Full Text Available Four male lambs (Katahdin; average live weight 25.9±2.9 kg with “T” type cannulas in the rumen and proximal duodenum were used in a 4×4 Latin square experiment to evaluate the influence of supplemental dry distillers grain with solubles (DDGS levels (0, 10, 20 and 30%, dry matter basis in substitution for dry-rolled (DR corn on characteristics of digestive function and digestible energy (DE of diet. Treatments did not influence ruminal pH. Substitution of DR corn with DDGS increased ruminal neutral detergent fiber (NDF digestion (quadratic effect, p<0.01, but decreased ruminal organic matter (OM digestion (linear effect, p<0.01. Replacing corn with DDGS increased (linear, p≤0.02 duodenal flow of lipids, NDF and feed N. But there were no treatment effects on flow to the small intestine of microbial nitrogen (MN or microbial N efficiency. The estimated UIP value of DDGS was 44%. Postruminal digestion of OM, starch, lipids and nitrogen (N were not affected by treatments. Total tract digestion of N increased (linear, p = 0.04 as the DDGS level increased, but DDGS substitution tended to decrease total tract digestion of OM (p = 0.06 and digestion of gross energy (p = 0.08. However, it did not affect the dietary digestible energy (DE, MJ/kg, reflecting the greater gross energy content of DDGS versus DR corn in the replacements. The comparative DE value of DDGS may be considered similar to the DE value of the DR corn it replaced up to 30% in the finishing diets fed to lambs.

  15. 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.

  16. 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)

  17. 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

  18. FED pumped limiter configuration issues

    International Nuclear Information System (INIS)

    Haines, J.R.; Fuller, G.M.

    1983-01-01

    Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Controlled synthesis and enhanced catalytic and gas-sensing properties of tin dioxide nanoparticles with exposed high-energy facets.

    Science.gov (United States)

    Wang, Xue; Han, Xiguang; Xie, Shuifen; Kuang, Qin; Jiang, Yaqi; Zhang, Subing; Mu, Xiaoliang; Chen, Guangxu; Xie, Zhaoxiong; Zheng, Lansun

    2012-02-20

    A morphology evolution of SnO(2) nanoparticles from low-energy facets (i.e., {101} and {110}) to high-energy facets (i.e., {111}) was achieved in a basic environment. In the proposed synthetic method, octahedral SnO(2) nanoparticles enclosed by high-energy {111} facets were successfully synthesized for the first time, and tetramethylammonium hydroxide was found to be crucial for the control of exposed facets. Furthermore, our experiments demonstrated that the SnO(2) nanoparticles with exposed high-energy facets, such as {221} or {111}, exhibited enhanced catalytic activity for the oxidation of CO and enhanced gas-sensing properties due to their high chemical activity, which results from unsaturated coordination of surface atoms, superior to that of low-energy facets. These results effectively demonstrate the significance of research into improving the physical and chemical properties of materials by tailoring exposed facets of nanomaterials. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Development of alternative fuels from coal-derived synthesis gas: Final topical report, demonstration of one-step slurry-phase process for the co-production of methanol and isobutanol

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    Liquid phase co-production of methanol and isobutanol (LPIBOH) was de, demonstrated at DOE`s Alternative Fuels Development Unit (AFDU) in LaPorte, Texas. Methanol and isobutanol are key intermediates in a synthesis gas-based route to methyl t-butyl ether (MTBE). The technology was demonstrated in a new 18 in. slurry bubble-column reactor that was designed to demonstrate higher pressures and temperatures,higher gas superficial velocities, and lower gas hourly space velocities--all of which are conducive to obtaining optimal isobutanol yield. The integration of the new reactor into the AFDU included the addition of a high-pressure synthesis gas compressor, a high-pressure hydrogen feed source, and a closed-loop methanol- solvent absorption system to remove CO{sub 2} from the unconverted synthesis gas. These modifications were completed in January 1994. The LPIBOH run followed after a short turnaround. It employed a cesium- promoted Cu/ZnO/Al{sub 2}O{sub 3} catalyst developed in Air Products` laboratories and subsequently scaled up to a production- sized batch. Over a thirteen day campaign on simulated Shell gasifier gas, the catalyst and reactor system were tested at a matrix of pressures (750, 1300, 1735 psig) and space velocities (3000, 5000, 8200 sL/kg-hr), representing numerous first-of-a-kind run conditions for the AFDU. Inlet gas superficial velocities spanned an impressive 0.16 to 1.0 ft/sec. Stable reactor performance for a full twelve-hour data period at 1.0 ft/sec was another significant milestone for the liquid phase technology program. Apart from the catalyst deactivation, the run successfully demonstrated mixed alcohol synthesis in a slurry bubble-column reactor, as well as all of the new equipment installed for the trial. Although the full capabilities of the new oxygenates system will not be tested until future runs, the design objectives for the modifications were met with respect to the LPIBOH run.

  5. Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, 1 April--30 June 30 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-25

    A series of CuMgCeO{sub x} catalysts have been prepared by coprecipitating the corresponding metal nitrates with a mixed solution of potassium carbonate and potassium hydroxide. Kinetic studies of methanol and ethanol coupling reactions on K-Cu/MgO/CeO{sub 2} and MgO/CeO{sub 2} catalysts indicate that Cu enhances the rates of alcohol dehydrogenation. The cross-coupling reactions of acetaldehyde and {sup 13}C-labeled methanol produce singly-labeled propionaldehyde, suggesting that it forms by the condensation of acetaldehyde and a reactive intermediate derived from methanol. Isobutyraldehyde, a precursor to isobutanol, forms via the condensation of propionaldehyde and a reactive C{sub 1} intermediate resulting from methanol. CO{sub 2}, one of the reaction products, poisons both basic and metal sites on Ce-containing CuMgO{sub x} catalysts, resulting in decreases in the rates of both alcohol dehydrogenation (Cu sites) and chain-growth condensation reactions (basic sites). CO{sub 2} inhibits ethanol dehydrogenation on both low-Cu and high-Cu CuMgCeO{sub x} catalysts; however, CO{sub 2} has no effect on the activity of low-Cu Ce-free Cu-MgO{sub x} catalysts, suggesting that the Cu on CuMgCeO{sub x} catalysts is more likely to be oxidized by CO{sub 2} to Cu{sup +} species that can be subsequently stabilized by CeO{sub 2}. CO{sub 2} effects on high-pressure isobutanol synthesis from CO/H{sub 2} have been studied on low- and high-Cu CuMgCeO{sub x} catalysts at 320{degrees}C and 4.5 MPa. CO{sub 2} addition and removal on low- and high-Cu catalysts show similar directional effects on CO conversion. CO conversion is lower at all space velocities in the presence of CO{sub 2}, and removal Of CO{sub 2} from the feed partially recovers CO conversion. CO{sub 2} decreases methanol and isobutanol productivities on both catalysts. Addition of 1-propanol to CO/H{sub 2} feed increases isobutanol production, suggesting that 1-propanol is a precursor to isobutanol.

  6. Degradação ruminal e síntese de proteína microbiana em bovinos alimentados com silagem de sorgo contendo tanino suplementado com concentrado ou uréia = Ruminal degradability and microbial protein synthesis in cattle fed sorghum silages with tannin supplemented with concentrate or urea

    Directory of Open Access Journals (Sweden)

    Simone Gisele de Oliveira

    2009-01-01

    Full Text Available Determinaram-se a degradabilidade ruminal da matéria seca (MS e a fibra em detergente neutro (FDN e a eficiência de síntese de proteína microbiana em animais que consomem dietas contendo silagem de sorgo com diferentes teores de tanino. A degradação in situfoi avaliada por meio da incubação ruminal de silagens de sorgo contendo nível 1 (N1 e nível 2 (N2 de tanino por 0, 6, 24, 48 e 96h. O delineamento experimental utilizado foi o quadrado latino4 x 4 duplicado. Os valores de degradabilidade potencial (DP da MS foram semelhantes entre as silagens, enquanto a degradabilidade efetiva (DE nas silagens foi reduzida ao adicionar concentradoà dieta. O fluxo de nitrogênio microbiano e a eficiência de síntese de proteína microbiana não foram afetados pela fonte de volumoso. Houve maior eficiência de síntese, expressa em relação à matériaorgânica e energia bruta digeridas no rúmen, nas dietas com silagem N1, quando as dietas foram suplementadas com concentrado. Não foi possível estabelecer relação consistente entre a presença de taninos e os parâmetros de degradação ruminal.This work aimed to determine ruminal parameters of dry mater (DM, neutral detergent fiber (NDF and protein synthesis in the rumen of animals fed diets based on sorghum with different tannin levels. In situ degradation was evaluated by rumen incubation of level 1 (L1 and level 2 (L2 sorghum silages during 0, 6, 24, 48 and 96 hours. A duplicated 4 x 4 Latin Square was used. Potential degradability (PD of DM was similar among silages, whereas the effectivedegradability (ED decreased when the diets were supplemented with concentrate. Microbial nitrogen flux and microbial synthesis efficiency were not affected by roughage source. The synthesis efficiency, expressed in organic matter and crude protein digested inrumen, was higher in L1 tannin diets supplemented with concentrate. There was not relationship between the presence of tannins and the parameters of

  7. Synthesis of chemically-modified single-walled carbon nanotubes by counter-current ammonia gas injection into the induction thermal plasma process

    Science.gov (United States)

    Shahverdi, Ali

    Pristine single-walled carbon nanotubes (SWCNTs) are poorly dispersible and insoluble in many solvents and need to be chemically modified prior to their use in many applications. This work is focused on the investigation of the synthesis of chemically modified SWCNTs material through an in situ approach. The main objectives of the presented research are: 1) to explore the in situ chemical process during the synthesis of SWCNT and 2) to closely examine the effect of a reactive environment on SWCNTs. Effects of the catalyst type and content on the SWCNTs final product, synthesized by induction thermal plasma (ITP), were studied to replace toxic cobalt (Co) in the feedstock. In this regard, three different catalyst mixtures (i.e. Ni-Y2O3, Ni-Co-Y2O3, and Ni-Mo-Y2O3) were used. Experimental results showed that the catalyst type affects the quality of the SWCNT final product. Similar quality SWCNTs can be produced when the same amount of Co was replaced by Ni. Moreover, the results observed in this experimental work were further explained by thermodynamic calculation results. Thermogravimetry (TG) was used throughout the work to characterize the SWCNTs product. TG was firstly standardized by studying the effects of three main instrumental parameters (temperature ramp, TR, initial mass of the sample, IM, and gas flow rate, FR) on the Tonset and full-width half maximum (FWHM) obtained from TG and derivative TG graphs of carbon black, respectively. Therefore, a two-level factorial statistical design was performed. The statistical analysis showed that the effect of TR, IM, and to a lower extent, FR, is significant on FWHM and insignificant on Tonset. A methodology was then developed based upon the SWCNTs synthesis using the ITP system, through an in situ chemistry approach. Ammonia (NH3) was selected and counter-currently injected into the ITP reactor at three different flow rates and by four different nozzle designs. Numerical simulation indicated a better mixing of NH3 in

  8. 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.

  9. Effects of Combining Feed Grade Urea and a Slow-release Urea Product on Characteristics of Digestion, Microbial Protein Synthesis and Digestible Energy in Steers Fed Diets with Different Starch:ADF Ratios.

    Science.gov (United States)

    López-Soto, M A; Rivera-Méndez, C R; Aguilar-Hernández, J A; Barreras, A; Calderón-Cortés, J F; Plascencia, A; Dávila-Ramos, H; Estrada-Angulo, A; Valdes-García, Y S

    2014-02-01

    As a result of the cost of grains, the replacement of grains by co-products (i.e. DDGS) in feedlot diets is a common practice. This change produces diets that contain a lower amount of starch and greater amount of fibre. Hypothetically, combining feed grade urea (U) with slow release urea (Optigen) in this type of diet should elicit a better synchrony between starch (high-rate of digestion) and fibre (low-rate of digestion) promoting a better microbial protein synthesis and ruminal digestion with increasing the digestible energy of the diet. Four cannulated Holstein steers (213±4 kg) were used in a 4×4 Latin square design to examine the combination of Optigen and U in a finishing diet containing different starch:acid detergent fibre ratios (S:F) on the characteristics of digestive function. Three S:F ratios (3.0, 4.5, and 6.0) were tested using a combination of U (0.80%) and Optigen (1.0%). Additionally, a treatment of 4.5 S:F ratio with urea (0.80% in ration) as the sole source of non-protein nitrogen was used to compare the effect of urea combination at same S:F ratio. The S:F ratio of the diet was manipulated by replacing the corn grain by dried distillers grain with solubles and roughage. Urea combination did not affect ruminal pH. The S:F ratio did not affect ruminal pH at 0 and 2 h post-feeding but, at 4 and 6 h, the ruminal pH decreased as the S:F ratio increased (linear, p<0.05). Ruminal digestion of OM, starch and feed N were not affected by urea combination or S:F ratio. The urea combination did not affect ADF ruminal digestion. ADF ruminal digestion decreased linearly (p = 0.02) as the S:F ratio increased. Compared to the urea treatment (p<0.05) and within the urea combination treatment (quadratic, p<0.01), the flow of microbial nitrogen (MN) to the small intestine and ruminal microbial efficiency were greater for the urea combination at a S:F ratio of 4.5. Irrespective of the S:F ratio, the urea combination improved (2.8%, p = 0.02) postruminal N

  10. Materials and design experience in a slurry-fed electric glass melter

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, S.M.; Larson, D.E.

    1981-08-01

    The design of a slurry-fed electric gas melter and an examination of the performance and condition of the construction materials were completed. The joule-heated, ceramic-lined melter was constructed to test the applicability of materials and processes for high-level waste vitrification. The developmental Liquid-Fed Ceramic Melter (LFCM) was operated for three years with simulated high-level waste and was subjected to conditions more severe than those expected for a nuclear waste vitrification plant.

  11. 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.)

  12. Mathematical Modeling of Liquid-fed Pulsed Plasma Thruster

    Directory of Open Access Journals (Sweden)

    Kaartikey Misra

    2018-01-01

    Full Text Available Liquid propellants are fast becoming attractive for pulsed plasma thrusters due to their high efficiency and low contamination issues. However, the complete plasma interaction and acceleration processes are still not very clear. Present paper develops a multi-layer numerical model for liquid propellant PPTs (pulsed plasma thrusters. The model is based on a quasi-steady flow assumption. The model proposes a possible acceleration mechanism for liquid-fed pulsed plasma thrusters and accurately predicts the propellant utilization capabilities and estimations for the fraction of propellant gas that is completely ionized and accelerated to high exit velocities. Validation of the numerical model and the assumptions on which the model is based on is achieved by comparing the experimental results and the simulation results for two different liquid-fed thrusters developed at the University of Tokyo. Simulation results shows that up-to 50 % of liquid propellant injected is completely ionized and accelerated to high exit velocities (>50 Km/s, whereas, neutral gas contribute to only 7 % of the total specific impulse and accelerated to low exit velocity (<4 Km/s. The model shows an accuracy up-to 92 % . Optimization methods are briefly discussed to ensure efficient propellant utilization and performance. The model acts as a tool to understand the background physics and to optimize the performance for liquid-fed PPTs.

  13. 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 ...

  14. 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

    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...

  15. 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.

  16. Síntese de proteína microbiana e concentrações de uréia em vacas alimentadas com diferentes fontes de proteína Estimation of microbial protein synthesis and urea nitrogen metabolism in lactating dairy cows fed diets supplemented with different protein sources

    Directory of Open Access Journals (Sweden)

    Douglas dos Santos Pina

    2006-08-01

    Full Text Available Foram utilizadas 12 vacas Holandesas puras e mestiças, distribuídas em três quadrados latinos 4 x 4, organizados de acordo com os dias em lactação, com o objetivo de avaliar o efeito de diferentes fontes protéicas sobre a síntese, a eficiência de síntese de proteína microbiana, a concentração de nitrogênio uréico no soro (NUS e no leite (NUL, a concentração de nitrogênio amoniacal e o pH ruminal. Utilizou-se silagem de milho como volumoso, na proporção de 60% da MS total. Os concentrados foram constituídos de diferentes fontes protéicas (FS - farelo de soja; FA38 - farelo de algodão 38%PB; FA28 - farelo de algodão 28%PB e FSU - farelo de soja + 5% de uréia/sulfato de amônia na MS do concentrado. As coletas spot de urina e de sangue foram realizadas no 18º dia do período experimental 4 horas após o fornecimento da alimentação aos animais, no período da manhã. Não foram observadas diferenças entre as dietas para o volume urinário (V, a excreção total de derivados de purinas (PT, a síntese e a eficiência de síntese de PB microbiana, expressa em g de PB/kg de NDT consumido. As concentrações de NUS e NUL também não diferiram entre as dietas. As concentrações de NUS e NUL e a síntese de PB microbiana não foram influenciadas pelas diferentes fontes de proteína dietéticas, inclusive com a adição de uréia (5% MS do concentrado.Twelve Holstein lactating dairy cows were blocked by days in milk and randomly assigned to three replicated 4 x 4 Latin square to evaluate the effect of different protein sources on efficiency of microbial protein synthesis, concentration of serum (NUS and milk (MUN urea nitrogen, and ruminal metabolism. A basal corn silage diet (60% of the total dry matter was fed plus one of the following proteins sources (DM basis: soybean meal (SBM, cottonseed meal with 38% of crude protein (CSM38, cottonseed meal with 28% of crude protein (CSM28, or soybean meal plus 5% of urea

  17. FED baseline engineering studies report

    Energy Technology Data Exchange (ETDEWEB)

    Sager, P.H.

    1983-04-01

    Studies were carried out on the FED Baseline to improve design definition, establish feasibility, and reduce cost. Emphasis was placed on cost reduction, but significant feasibility concerns existed in several areas, and better design definition was required to establish feasibility and provide a better basis for cost estimates. Design definition and feasibility studies included the development of a labyrinth shield ring concept to prevent radiation streaming between the torus spool and the TF coil cryostat. The labyrinth shield concept which was developed reduced radiation streaming sufficiently to permit contact maintenance of the inboard EF coils. Various concepts of preventing arcing between adjacent shield sectors were also explored. It was concluded that installation of copper straps with molybdenum thermal radiation shields would provide the most reliable means of preventing arcing. Other design studies included torus spool electrical/structural concepts, test module shielding, torus seismic response, poloidal conditions in the magnets, disruption characteristics, and eddy current effects. These additional studies had no significant impact on cost but did confirm the feasibility of the basic FED Baseline concept.

  18. FED baseline engineering studies report

    International Nuclear Information System (INIS)

    Sager, P.H.

    1983-04-01

    Studies were carried out on the FED Baseline to improve design definition, establish feasibility, and reduce cost. Emphasis was placed on cost reduction, but significant feasibility concerns existed in several areas, and better design definition was required to establish feasibility and provide a better basis for cost estimates. Design definition and feasibility studies included the development of a labyrinth shield ring concept to prevent radiation streaming between the torus spool and the TF coil cryostat. The labyrinth shield concept which was developed reduced radiation streaming sufficiently to permit contact maintenance of the inboard EF coils. Various concepts of preventing arcing between adjacent shield sectors were also explored. It was concluded that installation of copper straps with molybdenum thermal radiation shields would provide the most reliable means of preventing arcing. Other design studies included torus spool electrical/structural concepts, test module shielding, torus seismic response, poloidal conditions in the magnets, disruption characteristics, and eddy current effects. These additional studies had no significant impact on cost but did confirm the feasibility of the basic FED Baseline concept

  19. Facile Synthesis of Wormhole-Like Mesoporous Tin Oxide via Evaporation-Induced Self-Assembly and the Enhanced Gas-Sensing Properties

    Science.gov (United States)

    Li, Xiaoyu; Peng, Kang; Dou, Yewei; Chen, Jiasheng; Zhang, Yue; An, Gai

    2018-01-01

    Wormhole-like mesoporous tin oxide was synthesized via a facile evaporation-induced self-assembly (EISA) method, and the gas-sensing properties were evaluated for different target gases. The effect of calcination temperature on gas-sensing properties of mesoporous tin oxide was investigated. The results demonstrate that the mesoporous tin oxide sensor calcined at 400 °C exhibits remarkable selectivity to ethanol vapors comparison with other target gases and has a good performance in the operating temperature and response/recovery time. This might be attributed to their high specific surface area and porous structure, which can provide more active sites and generate more chemisorbed oxygen spices to promote the diffusion and adsorption of gas molecules on the surface of the gas-sensing material. A possible formation mechanism of the mesoporous tin oxide and the enhanced gas-sensing mechanism are proposed. The mesoporous tin oxide shows prospective detecting application in the gas sensor fields.

  20. Facile Synthesis of Wormhole-Like Mesoporous Tin Oxide via Evaporation-Induced Self-Assembly and the Enhanced Gas-Sensing Properties.

    Science.gov (United States)

    Li, Xiaoyu; Peng, Kang; Dou, Yewei; Chen, Jiasheng; Zhang, Yue; An, Gai

    2018-01-11

    Wormhole-like mesoporous tin oxide was synthesized via a facile evaporation-induced self-assembly (EISA) method, and the gas-sensing properties were evaluated for different target gases. The effect of calcination temperature on gas-sensing properties of mesoporous tin oxide was investigated. The results demonstrate that the mesoporous tin oxide sensor calcined at 400 °C exhibits remarkable selectivity to ethanol vapors comparison with other target gases and has a good performance in the operating temperature and response/recovery time. This might be attributed to their high specific surface area and porous structure, which can provide more active sites and generate more chemisorbed oxygen spices to promote the diffusion and adsorption of gas molecules on the surface of the gas-sensing material. A possible formation mechanism of the mesoporous tin oxide and the enhanced gas-sensing mechanism are proposed. The mesoporous tin oxide shows prospective detecting application in the gas sensor fields.

  1. Organochlorine compounds in breast-fed vs. bottle-fed infants: preliminary results at six weeks of age

    International Nuclear Information System (INIS)

    Lackmann, G.-M.; Schaller, K.-H.; Angerer, J.

    2004-01-01

    Background: Polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) are ubiquitous compounds with carcinogenic and teratogenic properties. They are chemically very stable and lipophilic and, therefore, accumulate in our food-chain. They are prenatally transmitted from mother to foetus, and mother's milk due to its high lipid content is an elimination pathway of special importance. Therefore, breast-feeding has been held responsible for elevated concentrations of these organochlorine compounds as well as for harmful effects in children later in life. Methods: Blood samples (2.5 ml) were taken from each 10 breast-fed and bottle-fed infants at 6 weeks of age. Blood specimens were immediately centrifuged, and serum was stored in glass tubes at -20 degree sign C until analysis. Three higher chlorinated PCB congeners (IUPAC nos. 138, 153 and 180), HCB, and the organic metabolite of DDT, p,p<<-DDE, were analysed with capillary gas chromatography with electron capture detection. Reliability was tested with gas chromatography-mass spectrometry. Results: There were no differences between the study groups of breast-fed and bottle-fed infants with regard to sex distribution, gestational age, birth-weight, age of the mothers, and smoking behaviour of the parents. In contrast, serum concentrations of all organochlorine compounds were significantly higher (P<0.0001) in breast-fed than in bottle-fed infants (mean): PCB 138, 0.38 vs. 0.10 μg/l; PCB 153, 0.49 vs. 0.1 μg/l; PCB 180, 0.31 vs. 0.04 μg/l; ΣPCB, 1.19 vs. 0.29 μg/l; HCB, 0.13 vs. 0.04 μg/l; p,p<<-DDE, 1.05 vs. 0.18 μg/l. Conclusions: Breast-feeding significantly increases the pollution of our infants with different organochlorine compounds as early as at 6 weeks of age. The progress of the present study will show whether this pollution will further increase with longer duration of breast-feeding, and whether breast-feeding bears any health risks for our

  2. 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.

  3. SYNTHESIS AND IN-VITRO STUDIES OF SOME NEW QUINOLINE ...

    African Journals Online (AJOL)

    mail: viswanath_fed@kluniversity.in. This work is licensed under the Creative Commons Attribution 4.0 International License. SYNTHESIS AND IN-VITRO STUDIES OF SOME NEW QUINOLINE 1,3,4-. THIADIAZOLO PYRIMIDIN DERIVATIVES.

  4. Natural gas; Gas Natural

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Carlos A.; Moraes, Claudia C.D. [Eletricidade de Sao Paulo S.A. (ELETROPAULO), Sao Paulo, SP (Brazil); Fonseca, Carlos H.F. [Centrais Eletricas de Santa Catarina S.A., Florianopolis, SC (Brazil); Silva, Clecio Fabricio da; Alves, Ricardo P. [Companhia Paranaense de Energia (COPEL), Curitiba, PR (Brazil); Sposito, Edivaldo Soares; Hulle, Lutero [Espirito Santo Centrais Eletricas S.A. (ESCELSA), Vitoria, ES (Brazil); S. Martins, Icaro da [Centrais Eletricas do Norte do Brasil S.A. (ELETRONORTE), Belem, PA (Brazil); Vilhena, Joao Luiz S. de [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil); Fagundes, Zaluar Aquino [Companhia Estadual de Energia Eletrica do Estado do Rio Grande do Sul, Porto Alegre, RS (Brazil)

    1996-12-31

    An increase in the consumption of natural gas in Brazil is an expected fact in what concerns energetic planning. This work presents the existing situation in what concerns natural gas utilization in the main world economies, as well as an analysis of the participation of this fuel among the energy final consumption per sources. The Brazilian consumption of natural gas is also analysed as well as the international agreement between Brazil and Bolivia for natural gas commercialization. Some legal, institutional and political aspects related to natural gas commercialization are also discussed. Finally, several benefits to be brought by the utilization of natural gas are presented 10 refs., 3 tabs.

  5. Synthesis of the report on the french gas market opening 24 october 2002; Synthese du rapport sur l'ouverture du marche gazier francais 24 octobre 2002

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  6. Gas and Gas Pains

    Science.gov (United States)

    ... Gas and gas pains Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  7. Synthesis of Aluminum-Titanium Carbide Micro and Nanocomposites by the Rotating Impeller In-Situ Gas-Liquid Reaction Method

    Science.gov (United States)

    Anza, Inigo; Makhlouf, Makhlouf M.

    2018-02-01

    The Rotating Impeller In-Situ Gas-Liquid Reaction Method is employed for the production of Al-TiC composites. The method relies on injecting a carbon-bearing gas by means of a rotating impeller into a specially formulated molten aluminum-titanium alloy. Under the optimal conditions of temperature and composition, the gas reacts preferentially with titanium to form titanium carbide particles. The design of the apparatus, the process operation window, and the routes for forming titanium carbide particles with different sizes are elucidated.

  8. Derivatives of 16alpha-hydroxy-dehydroepiandrosterone with an additional 7-oxo or 7-hydroxy substituent: Synthesis and gas chromatography/mass spectrometry analysis

    Czech Academy of Sciences Publication Activity Database

    Pouzar, Vladimír; Černý, Ivan; Hill, M.; Bičíková, M.; Hampl, R.

    2005-01-01

    Roč. 70, - (2005), s. 739-749 ISSN 0039-128X R&D Projects: GA ČR(CZ) GA203/03/0142 Institutional research plan: CEZ:AV0Z40550506 Keywords : steroid * synthesis * dehydroepiandrosterone Subject RIV: CC - Organic Chemistry Impact factor: 2.416, year: 2005

  9. Vapor-fed bio-hybrid fuel cell.

    Science.gov (United States)

    Benyamin, Marcus S; Jahnke, Justin P; Mackie, David M

    2017-01-01

    Concentration and purification of ethanol and other biofuels from fermentations are energy-intensive processes, with amplified costs at smaller scales. To circumvent the need for these processes, and to potentially reduce transportation costs as well, we have previously investigated bio-hybrid fuel cells (FCs), in which a fermentation and FC are closely coupled. However, long-term operation requires strictly preventing the fermentation and FC from harming each other. We introduce here the concept of the vapor-fed bio-hybrid FC as a means of continuously extracting power from ongoing fermentations at ambient conditions. By bubbling a carrier gas (N 2 ) through a yeast fermentation and then through a direct ethanol FC, we protect the FC anode from the catalyst poisons in the fermentation (which are non-volatile), and also protect the yeast from harmful FC products (notably acetic acid) and from build-up of ethanol. Since vapor-fed direct ethanol FCs at ambient conditions have never been systematically characterized (in contrast to vapor-fed direct methanol FCs), we first assess the effects on output power and conversion efficiency of ethanol concentration, vapor flow rate, and FC voltage. The results fit a continuous stirred-tank reactor model. Over a wide range of ethanol partial pressures (2-8 mmHg), power densities are comparable to those for liquid-fed direct ethanol FCs at the same temperature, with power densities >2 mW/cm 2 obtained. We then demonstrate the continuous operation of a vapor-fed bio-hybrid FC with fermentation for 5 months, with no indication of performance degradation due to poisoning (of either the FC or the fermentation). It is further shown that the system is stable, recovering quickly from disturbances or from interruptions in maintenance. The vapor-fed bio-hybrid FC enables extraction of power from dilute bio-ethanol streams without costly concentration and purification steps. The concept should be scalable to both large and small

  10. Prostaglandin E₂ production in mice is reduced by consumption of range-fed sources of red meat.

    Science.gov (United States)

    Broughton, K Shane; Rule, Daniel C; Handrich, Eldon

    2011-12-01

    Many view bison as a healthful alternative to other red meat sources, and as a way to decrease health risks, they associate it with meat consumption. Using mice as a model for immune function, we hypothesized that consumption of meat from range-fed bison would decrease prostaglandin (PG) E₂ and alter prostacyclin (PGI₂) release upon immune challenge when compared with mice fed meat from grain-finished bison, range-fed beef, feedlot steers, free-ranging elk, or chicken breast. After 2 weeks on an experimental diet and inflammatory stimulation, mouse peritoneal macrophage was isolated and analyzed in 12 animals per diet. Peritoneal cell arachidonic acid increased in response to a chicken-based diet (P meat of range-fed beef, range-fed bison, and elk but was highest with meat of grain-finished beef and intermediate in mice fed chicken (P meat had the greatest PGI₂, whereas PGI₂ was decreased in mice fed meat of either range bison, range beef, or chicken (P meat of steers or bison finished in a feedlot. We conclude that consumption of meats characteristic of range-fed ruminants or wild ungulates supports reduced PGE₂ and greater PGI₂ synthesis, indicating potentially greater immune health and lower blood clotting potential than meat from grain-finished cattle or bison in this model system. Published by Elsevier Inc.

  11. Rapid pressure swing absorption cleanup of post-shift reactor synthesis gas. Technical progress report, October 1, 1991--December 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Sirkar, K.K.; Majumdar, S.; Bhaumik, S.

    1992-01-31

    In order to increase the production rate of purified gas stream, a new hollow fiber module has been fabricated with more number of hollow fibers. A few experiments have also been carried out using a CO{sub 2}-N{sub 2} feed gas mixture and water as an absorbent in the new module. With the new module, it was possible to increase the production rate of purified gas by a significant amount while the cycle time for vacuum desorption was considerably reduced. Preparations are now being made to study the absorption behavior of CO{sub 2}-N{sub 2} gas mixture with a reactive absorbent liquid such as aqueous diethanolamine solution.

  12. Natural gas industry R and D

    International Nuclear Information System (INIS)

    Pavan, S.

    1992-01-01

    The last three decades have witnessed significant developments in engineering relative to the distribution and use of natural gas. This paper reviews these developments which, in natural gas distribution, include - polyethylene conduits, the use of radar to trace buried conduits, telemetering, innovative pressure reducing techniques and equipment, optimized retrofitting of buried pipelines, leak detection techniques, and energy recovery systems applied to pressure reducing operations. Relative to the efficient combustion and new uses of natural gas, the paper reviews the state-of-the-art in the design of compact wall mounted gas fired boilers for building space heating, gas fuelled space heating ventilation and air conditioning systems, and natural gas fed fuel cells

  13. Gas production, microbial synthesis by radio phosphorus and digestibility of babassu and mofumbo in sheep diets; Producao de gases, sintese microbiana pelo radiofosforo e digestibilidade do babacu e mofumbo em dietas de ovinos

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla Filho, Adibe Luiz

    2015-06-01

    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

  14. Cell proliferation in the atherosclerotic plaques of cholesterol-fed rabbits

    International Nuclear Information System (INIS)

    Cavallero, C.; Tondo, U. di; Mingazinni, P.L.; Nicosia, R.; Pericoli, M.N.; Sarti, P.; Spagnoli, L.G.; Villaschi, S.

    1976-01-01

    Tritiated thymidine radioautography was employed to study the effect of cortisol and other glucocorticoids on cellular proliferation in the aorta and pulmonary artery of rabbits with cholesterol atherosclerosis. Labelled cell counts showed that glucocorticoids, even after one day and at a relatively low dose, decrease sharply the deoxyribonucleic acid synthesis in the intimal plaques. The hormonal influence on [ 3 H] thymidine uptake seems to be a dose-dependent process. The relative potency of these steroids in inhibiting DNA synthesis in the plaques parallels closely their anti-inflammatory effectiveness. Conversely mineralocorticoids, including aldosterone and deoxycorticosterone, increase the rate of DNA synthesis in the plaques. It is concluded that the anti-atherogenic effect of glucocorticoids on cholesterol-fed rabbits may be due, at least partly, to the inhibitory effect of these steroids on the DNA synthesis of the cellular components of the intimal plaques

  15. Flame Synthesis of Nanosized Cu-Ce-O, Ni-Ce-O, and Fe-Ce-O Catalysts for the Water-Gas Shift (WGS) Reaction

    Science.gov (United States)

    2009-11-04

    32). These methods involve multiple steps, are time-consum- ing (e.g. solution based techniques), or present difficult control of the product ...by the flame synthesis method using cerium acetate dissolved in a mixture of acetic acid, 2-butanol, and isooctane (40). In this process, the...below 10 nm are formed via precursor evaporation, ceria nucleation, and sintering of the particles. The use of isooctane in this process increased the

  16. Gas distributor for fluidized bed coal gasifier

    Science.gov (United States)

    Worley, Arthur C.; Zboray, James A.

    1980-01-01

    A gas distributor for distributing high temperature reaction gases to a fluidized bed of coal particles in a coal gasification process. The distributor includes a pipe with a refractory reinforced lining and a plurality of openings in the lining through which gas is fed into the bed. These feed openings have an expanding tapered shape in the downstream or exhaust direction which aids in reducing the velocity of the gas jets as they enter the bed.

  17. 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...

  18. 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

  19. 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.

  20. Synthesis and analysis of novel polymers with high permselectivity and permeability in gas separation applications. Progress report, December 1991--December 1992

    Energy Technology Data Exchange (ETDEWEB)

    Koros, W.J.; Paul, D.R.

    1991-12-31

    Significant progress was made toward developing advanced materials for gas separation membrane applications and rationalizing molecular structure and efficacy: Synthesized and tested polyarylates based on terephthalic or isophthalic acid or a tertiary butyl derivative of the isophthalic acid with different diols to illustrate the effects of: ``opening`` the matrix by incorporation of bulky packing inhibiting groups such as the tertiary butyl moiety inhibition of backbone motion via meta connected backbone connections and ``tightening`` of the matrix by incorporation of polar halogens. Completed high temperature characterization of sorption and transport properties for novel materials. Continued studies of the phenyl-substituted polymers aimed at producing super stable high temperature useful polymers for gas separations. Synthesized a polyarylate based on the spirobiindane diol and bibenzoyl acid chloride to incorporate long flat packable bibenzoyl units between packing disruptive spirobiindane units in an attempt to control the segmental level morphology to produce highly selective ``bottleneck`` regions between highly open regions.

  1. Solid state synthesis of tin-doped ZnO at room temperature: Characterization and its enhanced gas sensing and photocatalytic properties

    International Nuclear Information System (INIS)

    Jia, Xiaohua; Fan, Huiqing; Afzaal, Mohammad; Wu, Xiangyang; O'Brien, Paul

    2011-01-01

    Highlights: → A room temperature solid-state reaction was used to prepare crystalline tin-doped ZnO. → The obtained products were well-dispersed, which is attributed to the difference in sizes between Zn and Sn atoms and the change of pH value. → Gas response of sample S4 to ethanol vapor can reach 124. The same sample exhibit photocatalysis characteristics to methyl orange (MO) solution. - Abstract: A room temperature solid-state reaction has been used to prepare crystalline tin-doped ZnO. Zinc nitrate hexahydrate, cetyltrimethyl ammonium bromide, stannic chloride pentahydrate and sodium hydroxide with proper ratios were ground together. As-synthesized samples were characterized by inductively coupled plasma analysis (ICP), scanning electron microscopy (SEM) and X-ray powder diffraction (XRD); The products were of different morphologies, well dispersed and exhibited good crystallinity, it is also found that the growth direction and morphology of ZnO depend on the amount of Sn doped, which is mainly caused by the difference in sizes between Zn and Sn atoms as well as the change of pH value. Moreover, gas sensing and photocatalytic properties of the obtained products were studied. The materials showed a high gas response to ethanol vapor, and the gas response can reach a maximum of R a /R g = 124. In addition, tin-doped ZnO materials exhibited improved photocatalytic performance toward methyl orange (MO) solution under a current density of 0.03 mg L -1 comparison with undoped ZnO.

  2. Calcination Method Synthesis of SnO2/g-C3N4 Composites for a High-Performance Ethanol Gas Sensing Application

    Science.gov (United States)

    Cao, Jianliang; Qin, Cong; Wang, Yan; Zhang, Bo; Gong, Yuxiao; Zhang, Huoli; Sun, Guang; Bala, Hari; Zhang, Zhanying

    2017-01-01

    The SnO2/g-C3N4 composites were synthesized via a facile calcination method by using SnCl4·5H2O and urea as the precursor. The structure and morphology of the as-synthesized composites were characterized by the techniques of X-ray diffraction (XRD), the field-emission scanning electron microscopy and transmission electron microscopy (SEM and TEM), energy dispersive spectrometry (EDS), thermal gravity and differential thermal analysis (TG-DTA), and N2-sorption. The analysis results indicated that the as-synthesized samples possess the two dimensional structure. Additionally, the SnO2 nanoparticles were highly dispersed on the surface of the g-C3N4nanosheets. The gas-sensing performance of the as-synthesized composites for different gases was tested. Moreover, the composite with 7 wt % g-C3N4 content (SnO2/g-C3N4-7) SnO2/g-C3N4-7 exhibits an admirable gas-sensing property to ethanol, which possesses a higher response and better selectivity than that of the pure SnO2-based sensor. The high surface area of the SnO2/g-C3N4 composite and the good electronic characteristics of the two dimensional graphitic carbon nitride are in favor of the elevated gas-sensing property. PMID:28468245

  3. 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.

  4. Method and system for natural gas utilization

    International Nuclear Information System (INIS)

    Halmoe, T.M.

    1995-01-01

    The invention relates to an method on reducing the emission of carbon oxides during methanol production. (a) A first part of the natural feeding gas is to be converted to synthesis gas consisting of CO, H 2 , CO 2 , H 2 O and non-converted natural gas. (b) A second part of the natural feeding gas is to be combusted for the generation of heat used in the conversion process by means of which the volumes of CO 2 and H 2 O are formed. (c) The synthesis gas from (a) is to be converted to a product gas flow consisting of methanol and non-converted synthesis gas. (d) The product gas flow from (c) is to be cooled, and methanol is to be separated. (e) A first part of the non-converted gas from the separation step (d) is to be combined with the synthesis gas from (a). (f) A second part of the non-converted gas from the separation step (d) together with CO 2 and H 2 O from step (b) is to be led to a shift reactor for making the equilibrium of CO, H 2 , CO, and H 2 O. (g) CO from step (f) is to be converted with methanol from step (d) for production of acetic acid. 1 fig

  5. Mustard Gas: Its Pre-World War I History

    Science.gov (United States)

    Duchovic, Ronald J.; Vilensky, Joel A.

    2007-01-01

    The Meyer-Clarke synthetic method was used in the German process for large scale production of mustard gas during World War I, which clearly shows the historical connection of synthesis of mustard gas.

  6. Gas processing handbook

    Energy Technology Data Exchange (ETDEWEB)

    1982-04-01

    Brief details are given of processes including: BGC-Lurgi slagging gasification, COGAS, Exxon catalytic coal gasification, FW-Stoic 2-stage, GI two stage, HYGAS, Koppers-Totzek, Lurgi pressure gasification, Saarberg-Otto, Shell, Texaco, U-Gas, W-D.IGI, Wellman-Galusha, Westinghouse, and Winkler coal gasification processes; the Rectisol process; the Catacarb and the Benfield processes for removing CO/SUB/2, H/SUB/2s and COS from gases produced by the partial oxidation of coal; the selectamine DD, Selexol solvent, and Sulfinol gas cleaning processes; the sulphur-tolerant shift (SSK) process; and the Super-meth process for the production of high-Btu gas from synthesis gas.

  7. Tokamak-FED plasma-engineering assessments

    International Nuclear Information System (INIS)

    Peng, Y.K.M.; Lyon, J.F.; Rutherford, P.H.

    1981-01-01

    A wide range of plasma assumptions and scenarios has been examined for the current US tokamak FED concept, which aims to provide a controlled, long pulse (approx. 100 s) burning plasma with an energy amplification of greater than or equal to 5, a fusion power of 180 MW, and a neutron wall load of greater than or equal to 0.4 MW/m 2 . The results of the assessment suggest that the current FED baseline parameters of R = 5.0 m, B/sub t/ = 3.6 T, a = 1.3 m, b = 2.1 m (D-shape), and I/sub p/ = 5.4 MA are appropriate in reaching the above plasma performance, despite uncertainties in several plasma physics areas, such as confinement scaling, achievable beta, impurity control, etc. To enhance the probability of achieving fusion ignition and to provide some margin against a short fall in our physics projections in FED, a limited operating capability at B/sub t/ = 4.6 T and I/sub p/ = 6.5 MA is incorporated. Various other options and remedies have also been assessed aiming to alleviate the impact of the uncertainties on the FED design concept. These approaches appear promising because they can be studied within the current fusion physics program and may lead to drastically more cost-effective FED concepts

  8. Synthesis, characterization, and comparative gas-sensing properties of Fe2O3 prepared from Fe3O4 and Fe3O4-chitosan

    International Nuclear Information System (INIS)

    Cuong, Nguyen Duc; Hoa, Tran Thai; Khieu, Dinh Quang; Lam, Tran Dai; Hoa, Nguyen Duc; Van Hieu, Nguyen

    2012-01-01

    Highlights: ► We have demonstrated a facile method to prepare Fe 3 O 4 nanoparticles and chitosan-coated Fe 3 O 4 nanoparticles. ► α-Fe 2 O 3 sensors prepared from those Fe 3 O 4 materials have been investigated and compared. ► The results show potential application of α-Fe 2 O 3 for CO sensors in environmental monitoring. - Abstract: In this paper, Fe 3 O 4 and chitosan (CS)-coated Fe 3 O 4 nanoparticles were synthesized via co-precipitation method and subsequent covalent binding of CS onto the surface for functionalization, respectively. Characterization of the crystal structures and morphologies of as-synthesized nanoparticles by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy demonstrated that Fe 3 O 4 had a cubic spinal structure with irregular shapes and average diameters of 10–20 nm. The surface states and magnetic properties of Fe 3 O 4 -CS nanoparticles were characterized by Fourier transform infrared spectra and vibrating sample magnetometry. Results showed that Fe 3 O 4 -CS nanoparticles possessed super-paramagnetic properties, with saturated magnetization up to 60 emu/g. In addition, Fe 3 O 4 and CS-coated Fe 3 O 4 nanoparticles were used in the fabrication of α-Fe 2 O 3 based gas sensors. Gas sensing measurements revealed that the α-Fe 2 O 3 gas sensor prepared from Fe 3 O 4 -CS had a better response to H 2 , CO, C 2 H 5 OH, and NH 3 compared with the device prepared from pristine Fe 3 O 4 . Furthermore, the α-Fe 2 O 3 sensor prepared from Fe 3 O 4 -CS nanoparticles exhibited the highest response to CO among the test gases, suggesting that it has great potential for practical applications in environmental monitoring.

  9. 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.

  10. 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.

  11. Proceedings of FED remote maintenance equipment workshop

    International Nuclear Information System (INIS)

    Sager, P.; Garin, J.; Hager, E.R.; Spampinato, P.T.; Tobias, D.; Young, N.

    1981-11-01

    A workshop was convened in two sessions in January and March 1981, on the remote maintenance equipment for the Fusion Engineering Device (FED). The objectives of the first session were to familiarize the participants with the status of the design of the FED and to develop a remote maintenance equipment list for the FED. The objective of the second session was to have the participants present design concepts for the equipment which had been identified in the first session. The equipment list was developed for general purpose and special purpose equipment. The general purpose equipment was categorized as manipulators and other, while the special purpose equipment was subdivided according to the reactor subsystem it serviced: electrical, magnetic, and nuclear. Both mobile and fixed base manipulators were identified. Handling machines were identified as the major requirement for special purpose equipment

  12. Proceedings of FED remote maintenance equipment workshop

    Energy Technology Data Exchange (ETDEWEB)

    Sager, P.; Garin, J.; Hager, E.R.; Spampinato, P.T.; Tobias, D.; Young, N.

    1981-11-01

    A workshop was convened in two sessions in January and March 1981, on the remote maintenance equipment for the Fusion Engineering Device (FED). The objectives of the first session were to familiarize the participants with the status of the design of the FED and to develop a remote maintenance equipment list for the FED. The objective of the second session was to have the participants present design concepts for the equipment which had been identified in the first session. The equipment list was developed for general purpose and special purpose equipment. The general purpose equipment was categorized as manipulators and other, while the special purpose equipment was subdivided according to the reactor subsystem it serviced: electrical, magnetic, and nuclear. Both mobile and fixed base manipulators were identified. Handling machines were identified as the major requirement for special purpose equipment.

  13. Tritium transport and control in the FED

    International Nuclear Information System (INIS)

    Rogers, M.L.

    1981-01-01

    The tritium systems for the FED have three primary purposes. The first is to provide tritium and deuterium fuel for the reactor. This fuel can be new tritium or deuterium delivered to the plant site, or recycled DT from the reactor that must be processed before it can be recycled. The second purpose of the FED tritium systems is to provide state-of-the-art tritium handling to limit worker radiation exposure and to minimize tritium losses to the environment. The final major objective of the FED tritium systems is to provide an integrated system test of the tritium handling technology necessary to support the fusion reactor program. Every effort is being made to incorporate available information from the Tritium System Test Assembly (TSTA) at Los Alamos National Laboratory, the Tokamak Fusion Test Reactor (TFTR) tritium systems, and the tritium handling information generated within DOE for the past 20 years

  14. 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

  15. 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.

  16. Synthesis and Enhanced Ethanol Gas Sensing Properties of the g-C3N4 Nanosheets-Decorated Tin Oxide Flower-Like Nanorods Composite

    Science.gov (United States)

    Qin, Cong; Zhang, Bo; Sun, Guang; Zhang, Zhanying

    2017-01-01

    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. PMID:28937649

  17. The economical production of alcohol fuels from coal-derived synthesis gas. Sixth quarterly technical progress report, January 1, 1993--March 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    Preliminary economic investigations have focused on cost reduction measures in the production of syngas from coal. A spread sheet model has been developed which can determine the cost of syngas production based upon the cost of equipment and raw materials and the market value of energy and by-products. In comparison to natural gas derived syngas, coal derived syngas is much more expensive, suggesting a questionable economic status of coal derived alcohol fuels. While it is possible that use of less expensive coal or significant integration of alcohol production and electricity production may reduce the cost of coal derived syngas, it is unlikely to be less costly to produce than syngas from natural gas. Fuels evaluation is being conducted in three parts. First, standard ASTM tests are being used to analyze the blend characteristics of higher alcohols. Second, the performance characteristics of higher alcohols are being evaluated in a single-cylinder research engine. Third, the emissions characteristics of higher alcohols are being investigated. The equipment is still under construction and the measurement techniques are still being developed. Of particular interest is n-butanol, since the MoS{sub 2} catalyst produces only linear higher alcohols. There is almost no information on the combustion and emission characteristics of n-butanol, hence the importance of gathering this information in this research.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Tris(trifluoromethyl)borane carbonyl, (CF3)3BCO-synthesis, physical, chemical and spectroscopic properties, gas phase, and solid state structure.

    Science.gov (United States)

    Finze, Maik; Bernhardt, Eduard; Terheiden, Annegret; Berkei, Michael; Willner, Helge; Christen, Dines; Oberhammer, Heinz; Aubke, Friedhelm

    2002-12-25

    Tris(trifluoromethyl)borane carbonyl, (CF(3))(3)BCO, is obtained in high yield by the solvolysis of K[B(CF(3))(4)] in concentrated sulfuric acid. The in situ hydrolysis of a single bonded CF(3) group is found to be a simple, unprecedented route to a new borane carbonyl. The related, thermally unstable borane carbonyl, (C(6)F(5))(3)BCO, is synthesized for comparison purposes by the isolation of (C(6)F(5))(3)B in a matrix of solid CO at 16 K and subsequent evaporation of excess CO at 40 K. The colorless liquid and vapor of (CF(3))(3)BCO decomposes slowly at room temperature. In the gas phase t(1/2) is found to be 45 min. In the presence of a large excess of (13)CO, the carbonyl substituent at boron undergoes exchange, which follows a first-order rate law. Its temperature dependence yields an activation energy (E(A)) of 112 kJ mol(-)(1). Low-pressure flash thermolysis of (CF(3))(3)BCO with subsequent isolation of the products in low-temperature matrixes, indicates a lower thermal stability of the (CF(3))(3)B fragment, than is found for (CF(3))(3)BCO. Toward nucleophiles (CF(3))(3)BCO reacts in two different ways: Depending on the nucleophilicity of the reagent and the stability of the adducts formed, nucleophilic substitution of CO or nucleophilic addition to the C atom of the carbonyl group are observed. A number of examples for both reaction types are presented in an overview. The molecular structure of (CF(3))(3)BCO in the gas phase is obtained by a combined microwave-electron diffraction analysis and in the solid state by single-crystal X-ray diffraction. The molecule possesses C(3) symmetry, since the three CF(3) groups are rotated off the two possible positions required for C(3)(v)() symmetry. All bond parameters, determined in the gas phase or in the solid state, are within their standard deviations in fair agreement, except for internuclear distances most noticeably the B-CO bond lengths, which is 1.69(2) A in the solid state and 1.617(12) A in the gas phase

  3. 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

  4. Ultrasound assisted synthesis of PANI/ZnMoO4 nanocomposite for simultaneous improvement in anticorrosion, physico-chemical properties and its application in gas sensing.

    Science.gov (United States)

    Bhanvase, B A; Darda, N S; Veerkar, N C; Shende, A S; Satpute, S R; Sonawane, S H

    2015-05-01

    Ultrasound assisted in-situ semi-batch emulsion polymerization has been used for the preparation of polyaniline (PANI) and PANI/ZnMoO4 nanocomposite with different loading of ZnMoO4 (ZM) nanoparticles. ZM nanoparticles were functionalized using Myristic acid (MA) for better compatibility with PANI. The cavitational effects induced due to ultrasonic irradiations have been shown significant enhancement in the dispersion of functionalized ZM nanoparticles into the PANI during ultrasound assisted in-situ emulsion polymerization process. TEM images of PANI/ZM nanocomposite particles give the direct evidence of fine dispersion and encapsulation of MA treated ZM nanoparticles in PANI matrix. The presence of ZM nanoparticles in PANI/ZM nanocomposite shows significant improvement in the mechanical (cross-cut adhesion), thermal, anticorrosion and sensing properties of PANI/ZM nanocomposite/alkyd coatings over PANI/alkyd and neat alkyd resin coating. Fine and uniform dispersion of ZM nanoparticles in PANI matrix using this novel synthesis method (PANI (p-type)/ZM (n-type) hetero-junction) improves LPG sensing ability and minimizes response time to sense LPG significantly compared with neat PANI. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. 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.

  6. Solid-State Method Synthesis of SnO2-Decorated g-C3N4 Nanocomposites with Enhanced Gas-Sensing Property to Ethanol

    Science.gov (United States)

    Cao, Jianliang; Qin, Cong; Wang, Yan; Zhang, Huoli; Sun, Guang; Zhang, Zhanying

    2017-01-01

    SnO2/graphitic carbon nitride (g-C3N4) composites were synthesized via a facile solid-state method by using SnCl4·5H2O and urea as the precursor. The structure and morphology of the as-synthesized composites were characterized by the techniques of X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive spectrometer (EDS), thermogravimetry-differential thermal analysis (TG-DTA), X-ray photoelectron spectroscopy (XPS), and N2 sorption. The results indicated that the composites possessed a two-dimensional (2-D) structure, and the SnO2 nanoparticles were highly dispersed on the surface of the g-C3N4 nanosheets. The gas-sensing performance of the samples to ethanol was tested, and the SnO2/g-C3N4 nanocomposite-based sensor exhibited admirable properties. The response value (Ra/Rg) of the SnO2/g-C3N4 nanocomposite with 10 wt % 2-D g-C3N4 content-based sensor to 500 ppm of ethanol was 550 at 300 °C. However, the response value of pure SnO2 was only 320. The high surface area of SnO2/g-C3N4-10 (140 m2·g−1) and the interaction between 2-D g-C3N4 and SnO2 could strongly affect the gas-sensing property. PMID:28772960

  7. Synthesis and enhanced acetone gas-sensing performance of ZnSnO3/SnO2 hollow urchin nanostructures

    Science.gov (United States)

    Lian, Dandan; Shi, Bing; Dai, Rongrong; Jia, Xiaohua; Wu, Xiangyang

    2017-12-01

    A kind of novel ZnSnO3/SnO2 hollow urchin nanostructure was synthesized by a facile, eco-friendly two-step liquid-phase process. The structure, morphology, and composition of samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption techniques. The results revealed that many tiny needle-like SnO2 nanowires with the average diameter of 5 nm uniformly grew on the surface of the ZnSnO3 hollow microspheres and the ZnSnO3/SnO2 hollow urchin nanostructures with different SnO2 content also were successfully prepared. In order to comprehend the evolution process of the ZnSnO3/SnO2 hollow urchin nanostructures, the possible growth mechanism of samples was illustrated via several experiments in different reaction conditions. Moreover, the gas-sensing performance of as-prepared samples was investigated. The results showed that ZnSnO3/SnO2 hollow urchin nanostructures with high response to various concentration levels of acetone enhanced selectivity, satisfying repeatability, and good long-term stability for acetone detection. Specially, the 10 wt% ZnSnO3/SnO2 hollow urchin nanostructure exhibited the best gas sensitivity (17.03 for 50 ppm acetone) may be a reliable biomarker for the diabetes patients, which could be ascribed to its large specific surface area, complete pore permeability, and increase of chemisorbed oxygen due to the doping of SnO2.

  8. Solid-State Method Synthesis of SnO2-Decorated g-C3N4 Nanocomposites with Enhanced Gas-Sensing Property to Ethanol

    Directory of Open Access Journals (Sweden)

    Jianliang Cao

    2017-05-01

    Full Text Available SnO2/graphitic carbon nitride (g-C3N4 composites were synthesized via a facile solid-state method by using SnCl4·5H2O and urea as the precursor. The structure and morphology of the as-synthesized composites were characterized by the techniques of X-ray diffraction (XRD, field-emission scanning electron microscopy (FESEM, transmission electron microscopy (TEM, energy dispersive spectrometer (EDS, thermogravimetry-differential thermal analysis (TG-DTA, X-ray photoelectron spectroscopy (XPS, and N2 sorption. The results indicated that the composites possessed a two-dimensional (2-D structure, and the SnO2 nanoparticles were highly dispersed on the surface of the g-C3N4 nanosheets. The gas-sensing performance of the samples to ethanol was tested, and the SnO2/g-C3N4 nanocomposite-based sensor exhibited admirable properties. The response value (Ra/Rg of the SnO2/g-C3N4 nanocomposite with 10 wt % 2-D g-C3N4 content-based sensor to 500 ppm of ethanol was 550 at 300 °C. However, the response value of pure SnO2 was only 320. The high surface area of SnO2/g-C3N4-10 (140 m2·g−1 and the interaction between 2-D g-C3N4 and SnO2 could strongly affect the gas-sensing property.

  9. Optimization of a bundle divertor for FED

    International Nuclear Information System (INIS)

    Hively, L.M.; Rothe, K.E.; Minkoff, M.

    1982-01-01

    Optimal double-T bundle divertor configurations have been obtained for the Fusion Engineering Device (FED). On-axis ripple is minimized, while satisfying a series of engineering constraints. The ensuing non-linear optimization problem is solved via a sequence of quadratic programming subproblems, using the VMCON algorithm. The resulting divertor designs are substantially improved over previous configurations

  10. Microbial biodiversity in glacier-fed streams.

    Science.gov (United States)

    Wilhelm, Linda; Singer, Gabriel A; Fasching, Christina; Battin, Tom J; Besemer, Katharina

    2013-08-01

    While glaciers become increasingly recognised as a habitat for diverse and active microbial communities, effects of their climate change-induced retreat on the microbial ecology of glacier-fed streams remain elusive. Understanding the effect of climate change on microorganisms in these ecosystems is crucial given that microbial biofilms control numerous stream ecosystem processes with potential implications for downstream biodiversity and biogeochemistry. Here, using a space-for-time substitution approach across 26 Alpine glaciers, we show how microbial community composition and diversity, based on 454-pyrosequencing of the 16S rRNA gene, in biofilms of glacier-fed streams may change as glaciers recede. Variations in streamwater geochemistry correlated with biofilm community composition, even at the phylum level. The most dominant phyla detected in glacial habitats were Proteobacteria, Bacteroidetes, Actinobacteria and Cyanobacteria/chloroplasts. Microorganisms from ice had the lowest α diversity and contributed marginally to biofilm and streamwater community composition. Rather, streamwater apparently collected microorganisms from various glacial and non-glacial sources forming the upstream metacommunity, thereby achieving the highest α diversity. Biofilms in the glacier-fed streams had intermediate α diversity and species sorting by local environmental conditions likely shaped their community composition. α diversity of streamwater and biofilm communities decreased with elevation, possibly reflecting less diverse sources of microorganisms upstream in the catchment. In contrast, β diversity of biofilms decreased with increasing streamwater temperature, suggesting that glacier retreat may contribute to the homogenisation of microbial communities among glacier-fed streams.

  11. GROWTH PERFORMANCE OF GRASSCUTTERS FED DIETS ...

    African Journals Online (AJOL)

    ABSTRACT. A total of ninety six-week old grasscutters were used in a study conducted to investigate the growth performance of grasscutters fed diets containing Moringa oleifera leaf meal (MOLM) and/or soybean meal. (SBM). The ninety (90) grasscutters were randomly assigned to three experimental groups consisting of ...

  12. Harmonic analysis of Doubly Fed Induction Generators

    DEFF Research Database (Denmark)

    Lindholm, Morten; Rasmussen, Tonny Wederberg

    2003-01-01

    This paper gives an overview of the frequency spectrum of the stator and rotor currents in a doubly fed induction generator (DFIG) used in wind power applications. The paper also presents a method to eliminate higher harmonics and interharmonics in the DFIG stator current. The method is implemented...

  13. ( Rattus norvegicus ) Fed with Dietary Cadmium

    African Journals Online (AJOL)

    Histological changes in the kidney tissues of albino rats (Rattus norvegicus) fed 100mg/kg body weight of cadmium sulphate incorporated as food material has been studied in vivo in an acute toxicological experiment. The behavioural pattern and physical changes in the rats were also investigated. Loss of weight and ...

  14. FED, Geometry Input Generator for Program TRUMP

    International Nuclear Information System (INIS)

    Schauer, D.A.; Elrod, D.C.

    1996-01-01

    1 - Description of program or function: FED reduces the effort required to obtain the necessary geometric input for problems which are to be solved using the heat-transfer code, TRUMP (NESC 771). TRUMP calculates transient and steady-state temperature distributions in multidimensional systems. FED can properly zone any body of revolution in one, or three dimensions. 2 - Method of solution: The region of interest must first be divided into areas which may consist of a common material. The boundaries of these areas are the required FED input. Each area is subdivided into volume nodes, and the geometrical properties are calculated. Finally, FED connects the adjacent nodes to one another, using the proper surface area, interface distance, and, if specified, radiation form factor and interface conductance. 3 - Restrictions on the complexity of the problem: Rectangular bodies can only be approximated by using a very large radius of revolution compared to the total radial thickness and by considering only a small angular segment in the circumferential direction

  15. MODIFIED EDGE FED SIERPINSKI CARPET MINIATURIZED ...

    African Journals Online (AJOL)

    This paper presented a modified edge fed Sierpinski carpet microstrip patch antenna for antenna miniaturization. The proposed design was etched as Sierpinski carpet to lower the antenna resonant frequency, which is used to reduce the conventional patch antenna size. After the Sierpinski carpet second iteration, the ...

  16. Supervision of Fed-Batch Fermentations

    DEFF Research Database (Denmark)

    Gregersen, Lars; Jørgensen, Sten Bay

    1999-01-01

    Process faults may be detected on-line using existing measurements based upon modelling that is entirely data driven. A multivariate statistical model is developed and used for fault diagnosis of an industrial fed-batch fermentation process. Data from several (25) batches are used to develop a mo...

  17. Increased kidney growth in formula-fed versus breast-fed healthy infants

    DEFF Research Database (Denmark)

    Schmidt, Ida M; Damgaard, Ida N; Boisen, Kirsten A

    2004-01-01

    versus breast feeding on kidney growth in a cohort of 631 healthy children examined at birth, and at 3 and 18 months of age. Kidney size was determined by ultrasonography and related to gender, age, body size, and feeding category (fully breast fed, partially breast fed, or fully formula fed at 3 months...... in relative kidney size were temporary, as they did not persist at 18 months of age, when all children received a normal mixed diet. The immediate renal effects of formula feeding should be taken into consideration for recommendations concerning infant feeding. Whether there are any long-term effects of early...

  18. Gas Diffusion in the CNS.

    Science.gov (United States)

    Rodriguez-Grande, Beatriz; Konsman, Jan-Pieter

    2018-02-01

    Gases have been long known to have essential physiological functions in the CNS such as respiration or regulation of vascular tone. Since gases have been classically considered to freely diffuse, research in gas biology has so far focused on mechanisms of gas synthesis and gas reactivity, rather than gas diffusion and transport. However, the discovery of gas pores during the last two decades and the characterization of diverse diffusion patterns through different membranes has raised the possibility that modulation of gas diffusion is also a physiologically relevant parameter. Here we review the means of gas movement into and within the brain through "free" diffusion and gas pores, notably aquaporins, discussing the role that gas diffusion may play in the modulation of gas function. We highlight how diffusion is relevant to neuronal signaling, volume transmission, and cerebrovascular control in the case of NO, one of the most extensively studied gases. We point out how facilitated transport can be especially relevant for gases with low permeability in lipid membranes like NH 3 and discuss the possible implications of NH 3 -permeable channels in physiology and hyperammonemic encephalopathy. We identify novel research questions about how modulation of gas diffusion could intervene in CNS pathologies. This emerging area of research can provide novel and interesting insights in the field of gas biology. © 2017 Wiley Periodicals, Inc.

  19. 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

  20. Sensor combination and chemometric variable selection for online monitoring of Streptomyces coelicolor fed-batch cultivations

    DEFF Research Database (Denmark)

    Ödman, Peter; Johansen, C.L.; Olsson, L.

    2010-01-01

    of biomass and substrate (casamino acids) concentrations, respectively. The effect of combination of fluorescence and gas analyzer data as well as of different variable selection methods was investigated. Improved prediction models were obtained by combination of data from the two sensors and by variable......Fed-batch cultivations of Streptomyces coelicolor, producing the antibiotic actinorhodin, were monitored online by multiwavelength fluorescence spectroscopy and off-gas analysis. Partial least squares (PLS), locally weighted regression, and multilinear PLS (N-PLS) models were built for prediction...

  1. 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...

  2. 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.

  3. 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).

  4. Facile synthesis of core/shell ZnO/ZnS nanofibers by electrospinning and gas-phase sulfidation for biosensor applications.

    Science.gov (United States)

    Baranowska-Korczyc, Anna; Sobczak, Kamil; Dłużewski, Piotr; Reszka, Anna; Kowalski, Bogdan J; Kłopotowski, Łukasz; Elbaum, Danek; Fronc, Krzysztof

    2015-10-07

    This study describes a new method of passivating ZnO nanofiber-based devices with a ZnS layer. This one-step process was carried out in H2S gas at room temperature, and resulted in the formation of core/shell ZnO/ZnS nanofibers. This study presents the structural, optical and electrical properties of ZnO/ZnS nanofibers formed by a 2 nm ZnS sphalerite crystal shell covering a 5 nm ZnO wurtzite crystal core. The passivation process prevented free carriers from capture by oxygen molecules and significantly reduced the impact of O2 on nanostructure conductivity. The conductivity of the nanofibers was increased by three orders of magnitude after the sulfidation, the photoresponse time was reduced from 1500 s to 30 s, and the cathodoluminescence intensity increased with the sulfidation time thanks to the removal of ZnO surface defects by passivation. The ZnO/ZnS nanofibers were stable in water for over 30 days, and in phosphate buffers of acidic, neutral and alkaline pH for over 3 days. The by-products of the passivation process did not affect the conductivity of the devices. The potential of ZnO/ZnS nanofibers for protein biosensing is demonstrated using biotin and streptavidin as a model system. The presented ZnS shell preparation method can facilitate the construction of future sensors and protects the ZnO surface from dissolving in a biological environment.

  5. 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.

  6. Conversion of glycerol to hydrogen rich gas.

    Science.gov (United States)

    Tran, Nguyen H; Kannangara, G S Kamali

    2013-12-21

    Presently there is a glut of glycerol as the by-product of biofuel production and it will grow as production increases. The conundrum is how we can consume this material and convert it into a more useful product. One potential route is to reform glycerol to hydrogen rich gas including synthesis gas (CO + H2) and hydrogen. However, there is recent literature on various reforming techniques which may have a bearing on the efficiency of such a process. Hence in this review reforming of glycerol at room temperature (normally photo-catalytic), catalysis at moderate and high temperature and a non-catalytic pyrolysis process are presented. The high temperature processes allow the generation of synthesis gas with the hydrogen to carbon monoxide ratios being suitable for synthesis of dimethyl ether, methanol and for the Fischer-Tropsch process using established catalysts. Efficient conversion of synthesis gas to hydrogen involves additional catalysts that assist the water gas shift reaction, or involves in situ capture of carbon dioxide and hydrogen. Reforming at reduced temperatures including photo-reforming offers the opportunity of producing synthesis gas or hydrogen using single catalysts. Together, these processes will assist in overcoming the worldwide glut of glycerol, increasing the competitiveness of the biofuel production and reducing our dependency on the fossil based, hydrogen rich gas.

  7. LM6000 gas turbine plant; LM6000 gas turbine plant

    Energy Technology Data Exchange (ETDEWEB)

    Nozaki, N.; Sato, T. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1998-09-01

    The LM6000 gas turbine is a most advanced industrial gas turbine derived from an aero-engine. The gas turbine has a power output of 45 MW with over 42% thermal efficiency, and such features as high efficiency, compactness, and easy maintenance. The gas turbine is used widely for electric power generation, marine propulsion and mechanical drive applications, particularly frequently for medium-capacity power plants because of its high efficiency. This paper summarizes the newest form of this LM6000 gas turbine, and introduces as its application example to power plants two examples of practical use in combined cycle power generation which is anticipated of increased use in the future. A combined cycle power plant for a paper mill in Indonesia is characterized by the gas turbine being a back-pressure turbine, where low pressure steam after having been used for power generation is fed to the paper mill. A combined cycle power plant for the Xinzhu scientific and industrial complex in Taiwan is characterized by adoption of a sucked air cooling device, which cools gas turbine sucked air temperature down to 7.2 deg C, and the gas turbine power generator being operated upto its maximum output of 45 MW. 7 figs., 1 tab.

  8. Zeolite membranes for efficient synthesis of biofuels

    OpenAIRE

    Sandström, Linda

    2009-01-01

    The greenhouse effect and the limited fossil oil resources have increased the demand of renewable fuels. Zeolite membranes have potential applications in numerous separation processes, and could be useful in the development of efficient processes for renewable fuel production. Methanol synthesis from synthesis gas is equilibrium limited, and continuous removal of products in a zeolite membrane reactor could improve the productivity of a conventional methanol synthesis process. In this work, m...

  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. Overwinter survival of mallards fed selenium

    Science.gov (United States)

    Heinz, G.H.; Fitzgerald, M.A.

    1993-01-01

    Adult male mallards (Anas platyrhynchos) were fed diets supplemented with 0, 10, 20, 40, or 80 g/g selenium in the form of selenomethionine. Mortality in each of these treatments was 0, 10, 25, 95, and 100%, respectively, during a 16-week exposure that started in November. After one week of treatment, body weights were significantly depressed by the 20, 40, and 80-ug/g selenium treatments, but not by 10 :g/g selenium. Four weeks after being returned to an untreated diet, the body weight of birds fed 20 ug/g selenium had increased to the point of being statistically inseparable from the weight of controls. Signs of selenium poisoning in the dead included severe emaciation, mottling of the liver, empty gizzard, and the presence of a yellowish fluid around some organs. Concentrations of selenium in blood were related to dietary treatments, but mortality was not clearly related to a threshold concentration of selenium in blood.

  11. Engineering testing requirements in FED/INTOR

    International Nuclear Information System (INIS)

    Abdou, M.A.; Nygren, R.E.; Morgan, G.D.; Trachsel, C.A.; Wire, G.; Oppermann, E.; Puigh, R.; Gold, R.E.

    1982-10-01

    The FED/INTOR critical issues activity has addressed three key testing requirements that have the largest impact on the design, operation and cost of FED/INTOR. These are: (1) the total testing time (fluence) during the device lifetime, (2) the minimum number of back-to-back cycles, and (3) the neutron wall load (power density in the first wall/blanket). The testing program activities were structured into three tasks in order to define the benefits, and in some cases, costs and risks of these testing requirements. The three tasks were carried out with wide participation of experts from a number of organizations in the United States. Similar effort was performed by Japan, the European Community and the Soviet Union

  12. Thermoelectric characterization of an intermediate temperature solid oxide fuel cell system directly fed by dry biogas

    International Nuclear Information System (INIS)

    De Lorenzo, G.; Corigliano, O.; Lo Faro, M.; Frontera, P.; Antonucci, P.; Zignani, S.C.; Trocino, S.; Mirandola, F.A.; Aricò, A.S.; Fragiacomo, P.

    2016-01-01

    Highlights: • Numerical Model (NM) of SOFC Cogenerative System (SCS) fed by dry biogas is set up. • NM simulates new Ni-Fe/CGO protective layer for direct CH 4 consumption at the anode. • NM simulates the anode carbonation phenomenon and is experimentally validated. • The performance parameters trends of SCS fed by three types of dry biogas are shown. • SEM images after 40 h of operation show that there is no anode carbon deposition. - Abstract: A properly manufactured intermediate temperature Solid Oxide Fuel Cell (SOFC) can be directly fed by dry biogas, considering also the electrochemical partial and total oxidation reactions of methane in the biogas at the anode. In this way the methane in the biogas is electrochemically consumed directly at the fuel cell without the need to mix the biogas with any reforming gas (steam, oxygen or carbon dioxide). In this article, a numerical model of an SOFC system with Ni-Fe/CGO electrocatalyst anode protective layer directly fed by dry biogas, in cogenerative arrangement and with anode exhaust gas recirculation is formulated. The influences of biogas composition, of fuel cell operating current density and of percentage of recirculated anode exhaust gas on the SOFC system performances were evaluated by calculation code. An SOFC test bench was set up to validate the calculation code results experimentally. Furthermore, the numerical model also considers the anode carbonation and evaluates the amount of carbon that can be formed in the anode at chemical equilibrium and quasi-equilibrium conditions associated with the specific anode protective layer used.

  13. Effects of a multi-strain Bacillus species-based direct-fed microbial on growth performance, nutrient digestibility, blood profile, and gut health in nursery pigs fed corn-soybean meal-based diets.

    Science.gov (United States)

    Cai, L; Indrakumar, S; Kiarie, E; Kim, I H

    2015-09-01

    This experiment was conducted to investigate the effect of a spp.-based direct-fed microbial (DFM) on growth performance, apparent total tract digestibility (ATTD), blood profile, intestinal histomorphology, and fecal gas emission in piglets fed corn and soybean meal-based diets. The DFM product was based on 1 strain of and 2 strains of and formulated to supply 1.5 × 10 cfu/g of feed. A total of 128 piglets ([Yorkshire × Landrace] × Duroc; 6.8 ± 0.6 kg BW; weaning age: 24 d) were housed in groups (4 pigs/pen, 2 barrows and 2 gilts) and fed diets ( = 16) without or with DFM in a 2-phase feeding program: d 0 to 14 (phase I) and 15 to 42 (phase II). Feed intake and BW were measured weekly. At the end of each phase, samples for blood urea nitrogen (BUN), blood creatinine, ATTD, and fecal noxious gas emission were taken. At termination, 12 piglets per treatment were killed to access intestinal tissues for histomorphology. Overall, pigs fed DFM had a greater ( < 0.05) G:F than pigs fed the control diet. In phase I, pigs fed DFM showed a greater ( < 0.05) ADG and lower ( < 0.05) concentration of BUN and fecal ammonia emission than the control group. In phase II, a greater ( < 0.05) ATTD of nitrogen and longer ( < 0.05) duodenum and jejunum villi were observed in pigs fed the DFM diet compared with the control group. In conclusion, inclusion of DFM improved growth performance and villi length of the duodenum and jejunum in nursery pigs. Furthermore, DFM enhanced protein utilization as demonstrated by increased nitrogen digestibility, lower BUN, and lower fecal ammonia release.

  14. Greenhouse gas emissions from natural ecosystems and agricultural lands in sub-Saharan Africa: synthesis of available data and suggestions for further research

    Science.gov (United States)

    Kim, Dong-Gill; Thomas, Andrew D.; Pelster, David; Rosenstock, Todd S.; Sanz-Cobena, Alberto

    2016-08-01

    This paper summarizes currently available data on greenhouse gas (GHG) emissions from African natural ecosystems and agricultural lands. The available data are used to synthesize current understanding of the drivers of change in GHG emissions, outline the knowledge gaps, and suggest future directions and strategies for GHG emission research. GHG emission data were collected from 75 studies conducted in 22 countries (n = 244) in sub-Saharan Africa (SSA). Carbon dioxide (CO2) emissions were by far the largest contributor to GHG emissions and global warming potential (GWP) in SSA natural terrestrial systems. CO2 emissions ranged from 3.3 to 57.0 Mg CO2 ha-1 yr-1, methane (CH4) emissions ranged from -4.8 to 3.5 kg ha-1 yr-1 (-0.16 to 0.12 Mg CO2 equivalent (eq.) ha-1 yr-1), and nitrous oxide (N2O) emissions ranged from -0.1 to 13.7 kg ha-1 yr-1 (-0.03 to 4.1 Mg CO2 eq. ha-1 yr-1). Soil physical and chemical properties, rewetting, vegetation type, forest management, and land-use changes were all found to be important factors affecting soil GHG emissions from natural terrestrial systems. In aquatic systems, CO2 was the largest contributor to total GHG emissions, ranging from 5.7 to 232.0 Mg CO2 ha-1 yr-1, followed by -26.3 to 2741.9 kg CH4 ha-1 yr-1 (-0.89 to 93.2 Mg CO2 eq. ha-1 yr-1) and 0.2 to 3.5 kg N2O ha-1 yr-1 (0.06 to 1.0 Mg CO2 eq. ha-1 yr-1). Rates of all GHG emissions from aquatic systems were affected by type, location, hydrological characteristics, and water quality. In croplands, soil GHG emissions were also dominated by CO2, ranging from 1.7 to 141.2 Mg CO2 ha-1 yr-1, with -1.3 to 66.7 kg CH4 ha-1 yr-1 (-0.04 to 2.3 Mg CO2 eq. ha-1 yr-1) and 0.05 to 112.0 kg N2O ha-1 yr-1 (0.015 to 33.4 Mg CO2 eq. ha-1 yr-1). N2O emission factors (EFs) ranged from 0.01 to 4.1 %. Incorporation of crop residues or manure with inorganic fertilizers invariably resulted in significant changes in GHG emissions, but results were inconsistent as the magnitude and direction of

  15. Protein and energy utilization by cockerels fed four different ...

    African Journals Online (AJOL)

    Protein and energy efficiency were significantly (p<0.05) improved in birds fed diet 3 and diet 4. These results are due to the consumption of higher levels of protein and energy by cockerels fed diet 3 and diet 4 coupled with the birds ability to better utilize these nutrients compared to those fed diet 1 and diet 2 respectively.

  16. Improved production of medium-chain-length Polyhydroxyalkanotes in glucose-based fed-batch cultivations of metabolically engineered Pseudomonas putida strains

    NARCIS (Netherlands)

    Poblete-Castro, I.; Rodriguez, A.L.; Lam, M.C.; Kessler, W.

    2014-01-01

    One of the major challenges in metabolic engineering for enhanced synthesis of value-added chemicals is to design and develop new strains which can be translated into well-controlled fermentation processes using bioreactors. The aim of this study was to assess the influence of various fed-batch

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

    Directory of Open Access Journals (Sweden)

    Zoe Ziaka

    2013-01-01

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

  18. 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.)

  19. HEPATIC FATTY ACID PROFILE OF RATS FED A TRIHEPTANOIN-BASED KETOGENIC DIET.

    Science.gov (United States)

    Vieira de Melo, Ingrid Sofia; Da Rocha Ataide, Terezinha; Lima de Oliveira, Suzana; Bezerra Bueno, Nassib; Duarte de Freitas, Johnnatan; Goulart Sant'Ana, Antônio Euzébio

    2015-07-01

    the aim of this study was to evaluate the influence of consumption of a ketogenic diet supplemented with triheptanoin, a medium-chain anaplerotic triacylglycerol, on the liver fatty acid profile of Wistar rats. three groups of male Wistar rats (n = 10) were submitted to an AIN-93 control diet, a triheptanoin- based ketogenic diet, or a soybean oil-based ketogenic diet for 60 days. Excised livers were subjected to lipid extraction and methylation to obtain fatty acids methyl esters, which were subjected to gas chromatography- mass spectrometry. compared to the rats fed the control diet, those fed ketogenic diets showed a significant reduction in the concentrations of 9-hexadecenoic and 9-octadecenoic acids, whereas those fed triheptanoin showed increased levels of octadecanoic acid. changes in the liver fatty acid profiles of the rats fed a triheptanoin-based or a soybean oil-based ketogenic diet did not seem to be related to the dietary fat source, but rather to the characteristics of the ketogenic diets themselves. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  20. Taurine prevents hypercholesterolemia in ovariectomized rats fed corn oil but not in those fed coconut oil.

    Science.gov (United States)

    Kishida, Taro; Miyazato, Shouko; Ogawa, Hiroshi; Ebihara, Kiyoshi

    2003-08-01

    We studied whether the type of dietary fatty acid influences the preventive effect of taurine on the ovarian hormone deficiency-induced increase in plasma cholesterol concentration in 6-mo-old ovariectomized rats. Rats were fed one of the following four diets for 28 d: purified diets based on corn oil, which is rich in linoleic acid, with or with out taurine (50 g/kg) or purified diets based on coconut oil, which is rich in lauric and myristic acids, with or without taurine. Body mass gain, food intake, liver weight and plasma apolipoprotein (apo) A-I, apo B, LDL and VLDL concentrations were not affected by the diets. On the other hand, taurine lowered the plasma total cholesterol concentration (P oil, but not in those fed coconut oil. In rats fed both types of oils, taurine increased the LDL receptor mRNA level (P cholesterol 7alpha-hydroxylase activity (P coconut oil, but not in those fed corn oil. Taurine increased liver total lipid (P oil, but not in those fed coconut oil. These results indicate that the effect of taurine on ovarian hormone deficiency-induced changes in cholesterol metabolism is influenced by the type of dietary fatty acids.

  1. Vitamin K deficiency in SPF-rats fed a semisynthetic irradiated diet

    International Nuclear Information System (INIS)

    Juhr, N.C.; Dietzel, L.; Horn, J.

    1975-01-01

    A case of vitamin K deficiency in male SPF-rats fed an irradiated semisynthetic diet (24% Soyprotein, 0.25% DL-Methionin, 48% Cornstarch, 10% Sucrose, 5% Soyoil and 7% Cellulose and a vitamin- and mineralmixture) with a vitamin K content of 0.63 mg/kg diet is reported including clinical symptoms, pathological findings, coagulation parameters and investigations of intestinal flora. The deficiency could be reproduced experimentally in SPF- and germfree male rats and prevented by vitamin K supplementation (K 3 in the water or K 1 parenterally). Monoassoziation with an E. coli strain as well as conventionalization of SPF-rats were effective to prevent deficiency symptoms. The significance of a stable intestinal flora for intestinal vitamin K synthesis is emphasized. Nutrients and their influence on the intestinal flora are discussed with special reference to the mechanism of coprophagy, which makes intestinal vitamin K synthesis available to the rat

  2. Optimized fed-batch fermentation of Scheffersomyces stipitis for efficient production of ethanol from hexoses and pentoses.

    Science.gov (United States)

    Unrean, Pornkamol; Nguyen, Nhung H A

    2013-03-01

    Scheffersomyces stipitis was cultivated in an optimized, controlled fed-batch fermentation for production of ethanol from glucose-xylose mixture. Effect of feed medium composition was investigated on sugar utilization and ethanol production. Studying influence of specific cell growth rate on ethanol fermentation performance showed the carbon flow towards ethanol synthesis decreased with increasing cell growth rate. The optimum specific growth rate to achieve efficient ethanol production performance from a glucose-xylose mixture existed at 0.1 h(-1). With these optimized feed medium and cell growth rate, a kinetic model has been utilized to avoid overflow metabolism as well as to ensure a balanced feeding of nutrient substrate in fed-batch system. Fed-batch culture with feeding profile designed based on the model resulted in high titer, yield, and productivity of ethanol compared with batch cultures. The maximal ethanol concentration was 40.7 g/L. The yield and productivity of ethanol production in the optimized fed-batch culture was 1.3 and 2 times higher than those in batch culture. Thus, higher efficiency ethanol production was achieved in this study through fed-batch process optimization. This strategy may contribute to an improvement of ethanol fermentation from lignocellulosic biomass by S. stipitis on the industrial scale.

  3. In vivo genetic toxicity studies in Chinese hamsters fed irradiated or unirradiated foodstuffs

    International Nuclear Information System (INIS)

    Altmann, H.

    1982-01-01

    Two in vivo genetic toxicity studies were performed in Chinese hamsters fed irradiated or unirradiated diets of chicken, fish or dates in order to detect possible mutagenic effects caused by irradiating these foodstuffs. The tests selected for study were: 1. Chromosomal analysis of bone narrow cells and 2. DNA metabolism in spleen cells. Chicken, fish and dates were irradiated with doses of 7, 2.5 and 1 kGy respectively. These investigations were subsequently extended to include the effects of irradiated dried onions, pulses and cocoa beans on DNA metabolism in Chinese hamster spleen cells only. Dried onions were irradiated with doses of 0.15, 9 and 15 kGy, pulses with 10 kGy and cocoa beans with 3.2 to 5 kGy. In addition, a fumigated cocoa bean group was included. No significant differences in chromosomal aberration rate were detected between groups fed irradiated or unirradiated diets. Dried dates, whether irradiated or not, showed some evidence of genetic toxicity in their effect on DNA metabolism in the spleen cells of Chinese hamsters. Both date diets caused more strand breaks DNA than are usual for Chinese hamster spleen cells, but DNA repair was not adversely affected. Chicken, both irradiated and unirradiated, was found to enhance replicative DNA synthesis but had no effect on the DNA repair process. Irradiated fish, however, caused enhanced DNA synthesis compared to unirradiated fish, but also had no adverse effect on DNA repair. Irradiated white beans also enhanced DNA synthesis compared to controls whereas unirradiated samples inhibited synthesis. (orig./MG)

  4. FED-A, an advanced performance FED based on low safety factor and current drive

    International Nuclear Information System (INIS)

    Peng, Y.K.M.; Rutherford, P.H.

    1983-08-01

    The FED-A study aims to quantify the potential improvement in cost-effectiveness of the Fusion Engineering Device (FED) by assuming low safety factor q (less than 2 as opposed to about 3) at the plasma edge and noninductive current drive (as opposed to only inductive current drive). The FED-A performance objectives are set to be : (1) ignition assuming International Tokamak Reactor (INTOR) plamsa confinement scaling, but still achieving a fusion power amplification Q greater than or equal to 5 when the confinement is degraded by a factor of 2; (2) neutron wall loading of about 1 MW/m 2 , with 0.5 MW/m 2 as a conservative lower bound; and (3) more clearly power-reactor-like operations, such as steady state

  5. Gas gangrene

    Science.gov (United States)

    Tissue infection - Clostridial; Gangrene - gas; Myonecrosis; Clostridial infection of tissues; Necrotizing soft tissue infection ... Gas gangrene is most often caused by bacteria called Clostridium perfringens. It also can be caused by ...

  6. Endogenous synthesis of n-3 PUFA modifies fatty acid composition of kidney phospholipids and eicosanoid levels in the fat-1 mouse.

    Science.gov (United States)

    Kelton, D; Lysecki, C; Aukema, H; Anderson, B; Kang, J X; Ma, D W L

    2013-09-01

    The goal of the present study was to determine whether endogenous synthesis of n-3 polyunsaturated fatty acids (PUFA) in the fat-1 mouse is comparable to fish oil feeding with respect to kidney n-3 PUFA composition and eicosanoid levels. Wild-type and heterozygous fat-1 mice, capable of synthesizing n-3 PUFA endogenously, were given diets enriched in either n-3 or n-6 PUFA in a 2×2 factorial design and terminated after 12 weeks. Kidney phospholipid fatty acids were analysed by gas chromatography. Kidney eicosanoids were analysed by liquid chromatography tandem mass spectrometry. Relative to control mice fed n-6 PUFA, n-3 PUFA fed and fat-1 mice had higher levels of kidney phospholipid n-3 PUFA, and lower levels of n-6 PUFA and eicosanoids. However, mice fed n-3 PUFA mice had higher levels of n-3 PUFA and lower levels of eicosanoids as compared to fat-1 mice. In conclusion, diet feeding had a greater impact on kidney fatty acid composition and eicosanoid levels than the genetic effect of the fat-1 gene. However, the fat-1 mouse remains a close approximation that can be used as a complementary model to study the role of n-3 PUFA in the kidney. © 2013 Elsevier Ltd. All rights reserved.

  7. Gas separating

    Science.gov (United States)

    Gollan, Arye Z.

    1990-12-25

    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.

  8. Desempenho de borregas Santa Inês alimentadas com duas fontes de nitrogênio não-protéico em dietas formuladas estimulando a síntese de proteína microbiana ruminal Performance of Santa Ines ewe lambs fed with two non-protein nitrogen sources in diets formulated to stimulate the ruminal microbial protein synthesis

    Directory of Open Access Journals (Sweden)

    Fábio Arantes Quintão

    2009-02-01

    Full Text Available O experimento foi realizado na Universidade Federal de Lavras (UFLA, com o objetivo de avaliar a eficiência de utilização de duas fontes de NNP (uréia e da amiréia, bem como o nível de intensidade para a síntese de proteína microbiana ruminal sobre o desempenho de ovinos. Foram utilizadas 24 borregas da raça Santa Inês distribuídas em um delineamento experimental inteiramente casualizado, em um esquema fatorial 2x3, sendo duas fontes de NNP e três níveis de intensidade na síntese de proteína microbiana ruminal (100% do potencial de síntese, 60% do potencial de síntese e síntese mínima, apenas suficiente para atendimento da exigência em proteína metabolizável. As variáveis analisadas foram: ingestão de MS (IMS, ganho de peso médio diário e conversão alimentar. Os resultados obtidos demonstraram que a maximização da síntese de PB microbiana, independentemente do tipo de fonte de NNP utilizada, não influenciou no desempenho animal, consumo e conversão alimentar. Para ovinos na proximidade do tamanho adulto, quando não se objetiva elevados níveis de desempenho, o não atendimento do potencial do rúmen em sintetizar proteína microbiana não resulta em pior desempenho na produção animal.The experiment was carried out at Federal University of Lavras (UFLA, with the aim of evaluating the efficiency of using two non-protein nitrogen sources (urea and amireia, as well as the level of intensity for the synthesis of ruminal microbial protein upon the ewe performance. Twenty-four female lambs of Santa Inês breed distributed into a completely randomized experimental design in a factorial scheme 2x3 were used, being two sources of NPN and three levels of microbial synthesis intensity (100% and 60% of synthesis potential and minimal synthesis. The variables studied were DM intake, daily average weight gain and feed conversion. The results showed that maximizing the microbial protein synthesis did not influence the animal

  9. Ammonia synthesis at low temperatures

    DEFF Research Database (Denmark)

    Rod, Thomas Holm; Logadottir, Ashildur; Nørskov, Jens Kehlet

    2000-01-01

    Density functional theory (DFT) calculations of reaction paths and energies for the industrial and the biological catalytic ammonia synthesis processes are compared. The industrial catalyst is modeled by a ruthenium surface, while the active part of the enzyme is modeled by a MoFe6S9 complex...... have been carried out to evaluate its feasibility. The calculations suggest that it might be possible to catalytically produce ammonia from molecular nitrogen at low temperatures and pressures, in particular if energy is fed into the process electrochemically. (C) 2000 American Institute of Physics....

  10. Exocrine pancreatic secretion is stimulated in piglets fed Fish oil compared with those fed Coconut Oil or Lard

    DEFF Research Database (Denmark)

    Hedemann, Mette Skou; Pedersen, Asger Roer; Engberg, Ricarda M.

    2001-01-01

    An experiment was conducted to study the effect of feeding diets containing fat sources with different fatty acid composition (fish oil, coconut oil or lard, 10 g/100 g diet) on exocrine pancreatic secretion in piglets after weaning. A total of 16 barrows were weaned at 4 wk of age; 3 d later...... the coconut oil or lard diets. The output [U/(h. kg(0.75))] of lipase was higher in piglets fed fish oil than in piglets fed lard or coconut oil. The output of colipase was greater in piglets fed fish oil and coconut oil than in those fed lard. The dietary treatments did not affect the output of carboxylester...... hydrolase. The output of trypsin was significantly lower in piglets fed lard than in piglets fed fish oil or coconut oil diets and the output of carboxypeptidase B was greater in those fed the fish oil diet. Protein, chymotrypsin, carboxypeptidase A, elastase and amylase outputs did not differ among...

  11. Ruslands Gas

    OpenAIRE

    Elkjær, Jonas Bondegaard

    2008-01-01

    This paper is about Russian natural gas and the possibility for Russia to use its reserves of natural gas politically towards the European Union to obtain some political power. Russia owns 32,1 % of the world gas reserves, and The European Union is getting 50 % of its gas import from Russia. I will use John Mearsheimer’s theory ”The Tragedy of Great Power Politics” to explain how Russia can use its big reserves of gas on The European Union to get political influence. This paper is about Ru...

  12. Ruslands Gas

    OpenAIRE

    Elkjær, Jonas Bondegaard

    2008-01-01

    This paper is about Russian natural gas and the possibility for Russia to use its reserves of natural gas politically towards the European Union to obtain some political power. Russia owns 32,1 % of the world gas reserves, and The European Union is getting 50 % of its gas import from Russia. I will use John Mearsheimer’s theory ”The Tragedy of Great Power Politics” to explain how Russia can use its big reserves of gas on The European Union to get political influence.

  13. Harnessing gas

    International Nuclear Information System (INIS)

    1998-01-01

    Nigeria produces almost two million barrels of oil a day from its oil fields in the Niger Delta area. Most of the oil comes from reservoirs containing gas, which is produced with the oil. This associated gas is separated from the oil at flow stations and more than 95 per cent of it is flared-currently a total of some two billion standard cubic feet per day (scf/d), which is estimated to be about a quarter of the gas the world flares and vents. The energy available from Nigeria's flared gas is prodigious, equivalent to one quarter of France's gas requirements. The company recognises that flaring wastes a valuable resource and is environmentally damaging. It aims to stop necessary flaring as soon as possible through a series of projects to harness or conserve this gas. Several gas gathering and conservation projects are already underway in response to emerging markets while other plans await new markets. The company is committed to reduce gas flaring as soon as is feasible to the minimum needed to maintain safe operations. But why are solutions being found only now? why has Nigeria been flaring gas for so long? These question lie at the crux of the debate about Nigeria and gas flaring and the answers, which continue to have a major impact on associated gas development today, are rooted in history, economics and geography

  14. Coupling Between Waveguide-Fed Slot Arrays

    Science.gov (United States)

    Rengarajan, Sembiam

    2011-01-01

    Coupling between two waveguide-fed planar slot arrays has been investigated using full-wave analysis. The analysis employs the method-of-moments solution to the pertinent coupled integral equations for the aperture electric field of all slots. In order to compute coupling between two arrays, the input port of the first array is excited with a TE(sub 10) mode wave while the second one is match-terminated. After solving the moment method matrix equations, the aperture fields of all slots are obtained and thereby the TE(sub 10) mode wave received at the input port of the second array is determined. Coupling between two arrays is the ratio of the wave amplitude arriving in the second array port to the incident wave amplitude at the first array port. The coupling mechanism has been studied as a function of spacing between arrays in different directions, e.g. the electric field plane, the magnetic field plane, and the diagonal plane. Computed coupling values are presented for different array geometries. This work is novel since it provides a good understanding of coupling between waveguide-fed slot arrays as a function of spacing and orientation for different aperture distributions and array architectures. This serves as a useful tool for antenna design engineers and system engineers.

  15. Catalytic hot gas cleaning of gasification gas

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  16. The hemolymph proteome of fed and starved Drosophila larvae.

    Directory of Open Access Journals (Sweden)

    Björn Handke

    Full Text Available The co-operation of specialized organ systems in complex multicellular organisms depends on effective chemical communication. Thus, body fluids (like blood, lymph or intraspinal fluid contain myriads of signaling mediators apart from metabolites. Moreover, these fluids are also of crucial importance for immune and wound responses. Compositional analyses of human body fluids are therefore of paramount diagnostic importance. Further improving their comprehensiveness should increase our understanding of inter-organ communication. In arthropods, which have trachea for gas exchange and an open circulatory system, the single dominating interstitial fluid is the hemolymph. Accordingly, a detailed analysis of hemolymph composition should provide an especially comprehensive picture of chemical communication and defense in animals. Therefore we used an extensive protein fractionation workflow in combination with a discovery-driven proteomic approach to map out the detectable protein composition of hemolymph isolated from Drosophila larvae. Combined mass spectrometric analysis revealed more than 700 proteins extending far beyond the previously known Drosophila hemolymph proteome. Moreover, by comparing hemolymph isolated from either fed or starved larvae, we provide initial provisional insights concerning compositional changes in response to nutritional state. Storage proteins in particular were observed to be strongly reduced by starvation. Our hemolymph proteome catalog provides a rich basis for data mining, as exemplified by our identification of potential novel cytokines, as well as for future quantitative analyses by targeted proteomics.

  17. 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.

  18. In vivo determination of arterial collagen synthesis in atherosclerotic rabbits

    International Nuclear Information System (INIS)

    Opsahl, W.P.; DeLuca, D.J.; Ehrhart, L.A.

    1986-01-01

    Collagen and non-collagen protein synthesis rates were determined in vivo in tissues from rabbits fed a control or atherogenic diet supplemented with 2% peanut oil and 0.25% cholesterol for 4 months. Rabbits received a bolus intravenous injection of L-[ 3 H]-proline (1.0 mCi/kg) and unlabeled L-proline (7 mmoles/kg) in 0.9% NaCl. Plasma proline specific activity decreased only 20% over 5 hr and was similar to the specific activity of free proline in tissues. Thoracic aortas from atherosclerotic rabbits exhibited raised plaques covering at least 75% of the surface. Thoracic intima plus a portion of the media (TIM) was separated from the remaining media plus adventitia (TMA). Dry delipidated weight, total collagen content, and collagen as a percent of dry weight were increased significantly in the TIM of atherosclerotic rabbits. Collagen synthesis rates and collagen synthesis as a percent of total protein synthesis were likewise increased both in the TIM and in the abdominal aortas. No differences from controls either in collagen content or collagen synthesis rates were observed in the TMA, lung or skin. These results demonstrate for the first time in vivo that formation of atherosclerotic plaques is associated with increased rates of collagen synthesis. Furthermore, as previously observed with incubations in vitro, collagen synthesis was elevated to a greater extent than noncollagen protein synthesis in atherosclerotic aortas from rabbits fed cholesterol plus peanut oil

  19. 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.

  20. Synthesis, characterization and gas sensing performance of ...

    Indian Academy of Sciences (India)

    azide and 3.2 g sodium hydroxide was taken in a Teflon autoclave containing 20 ml distilled water. Then the reaction mixture was shaken vigorously to obtain homogeneity. After the reaction period, the product was washed with deionized water, and dried overnight at 373 K to remove the weekly adsorbed water. 1557 ...

  1. Synthesis, characterization and gas sensing performance of ...

    Indian Academy of Sciences (India)

    The product obtained was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, thermogravimetric analysis and magic-angle spin nuclear magneticresonance (MAS NMR). The crystal structure of the product was determined from X-ray powder diffraction data by applying ...

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

    Indian Academy of Sciences (India)

    Hydroxyapatite (HAp) biomaterial ceramic was synthesized by three different processing routes viz. wet chemical process, microwave irradiation process, and hydrothermal technique. The synthesized ceramic powders were characterized by SEM, XRD, FTIR and XPS techniques. The dielectric measurements were carried ...

  3. Synthesis, characterization and gas sensing performance of ...

    Indian Academy of Sciences (India)

    The product obtained was characterized by Fourier transform infrared spectroscopy,. X-ray diffraction, scanning electron microscope, thermogravimetric analysis and magic-angle spin nuclear mag- netic resonance (MAS NMR). The crystal structure of the product was determined from X-ray powder diffraction data by ...

  4. 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

  5. Metabolism of L-leucine-U-14C in young rats fed excess glycine diets

    International Nuclear Information System (INIS)

    Takeuchi, Hisanao; Tadauchi, Nobuo; Muramatsu, Keiichiro

    1975-01-01

    As reported previously, while the growth-depressing effect of excess glycine was prevented by supplementing L-arginine and L-methionine, the degradation of glycine-U-(SUP 14)C into expired carbon dioxide was not accelerated by the supplement of both amino acids. However, it was found that the incorporation of the isotope into the lipids of livers and carcasses increased in the rats fed the excess glycine diet containing both amino acids. The lipid synthesis utilizing excess glycine may be accelerated by adding both amino acids to the 10% casein diet containing excess glycine. In the present experiment, the metabolic fate of L-leucine-U-(SUP 14)C was studied with the rats fed the excess glycine diet with or without L-arginine and L-methionine. 10% casein (10C), 10% casein diet containing 7% glycine (10C7G), or 10C7G Supplemented with 1.4% L-arginine-HCL and 0.9% L-methionine (10C7GArgMet) was fed to each rat, and the diet suspension containing 4 sup(μ)Ci of L-leucine-U-(SUP 14)C per 100 g of body weight was fed forcibly after 12 hr fast. The radioactivity in expired carbon dioxide, TCA soluble fraction, protein, glycogen, lipids and urine, and the concentration of free amino acids in blood plasma, livers and urine were measured. The body weight gain and food intake of the 10C7G group were much smaller than those of the other groups. The recovery of (SUP 14)C-radioactivity in expired carbon dioxide was much lower in the 10C7GArgMet group than that of the other groups. (Kako, I.)

  6. Fire Synthesis

    Indian Academy of Sciences (India)

    1000ºC or special infrastructure which require careful maintenance. In such a situation fire synthesis is a simpler method that can be adopted for the bulk production of high purity alumina and related oxides. Fire Synthesis. Preparation of Alumina ...

  7. B-doping of vapour-liquid-solid grown Au-catalysed and Al-catalysed Si nanowires: effects of B2H6 gas during Si nanowire growth and B-doping by a post-synthesis in situ plasma process

    International Nuclear Information System (INIS)

    Whang, S-J; Lee, S; Chi, D-Z; Yang, W-F; Cho, B-J; Liew, Y-F; Kwong, D-L

    2007-01-01

    In this study, B-doping of vapour-liquid-solid (VLS) grown Si nanowires was studied. First, the different effects of B 2 H 6 gas on nanowire structures during VLS growth of both Au-catalysed and Al-catalysed Si nanowires were investigated. While Au-catalysed Si nanowires grown with B 2 H 6 gas reveal significant morphological changes, resulting in cone-shaped nanowires, structures comparable to un-doped nanowires were observed from Al-catalysed Si nanowires, which may be explained by thermodynamic properties of Au and Al catalyst in the presence of boron. In addition, successful incorporation of boron and controllability of its concentration in Si nanowires, maintaining the structural quality of the nanowires, was achieved by a post-synthesis in situ plasma B 2 H 6 doping process

  8. 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.

  9. 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

  10. L-strip proximity fed ga

    Directory of Open Access Journals (Sweden)

    Ashish Singh

    2014-03-01

    Full Text Available In this article, the analysis of dualband L-strip fed compact semi-circular disk microstrip patch antenna has been presented using circuit theory concept. The antenna parameters such as return loss, VSWR and radiation pattern are calculated. The effect of geometric dimensions of the proposed antenna such as length of vertical and horizontal portion of L-strip is investigated. It is found that antenna resonate at two distinct modes i.e. 1.3 GHz and 6.13 GHz for lower and upper resonance frequencies respectively. The bandwidth of the proposed antenna at lower resonance frequency is 6.61% (simulated and 10.64% (theoretical whereas at upper resonance frequency, it is 6.02% (simulated and 9.06 % (theoretical. The theoretical results are compared with IE3D simulation results as well as experimental results and they are in close agreement.

  11. 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.

  12. Gasoline from Wood via Integrated Gasification, Synthesis, and Methanol-to-Gasoline Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, S. D.; Tarud, J. K.; Biddy, M. J.; Dutta, A.

    2011-01-01

    This report documents the National Renewable Energy Laboratory's (NREL's) assessment of the feasibility of making gasoline via the methanol-to-gasoline route using syngas from a 2,000 dry metric tonne/day (2,205 U.S. ton/day) biomass-fed facility. A new technoeconomic model was developed in Aspen Plus for this study, based on the model developed for NREL's thermochemical ethanol design report (Phillips et al. 2007). The necessary process changes were incorporated into a biomass-to-gasoline model using a methanol synthesis operation followed by conversion, upgrading, and finishing to gasoline. Using a methodology similar to that used in previous NREL design reports and a feedstock cost of $50.70/dry ton ($55.89/dry metric tonne), the estimated plant gate price is $16.60/MMBtu ($15.73/GJ) (U.S. $2007) for gasoline and liquefied petroleum gas (LPG) produced from biomass via gasification of wood, methanol synthesis, and the methanol-to-gasoline process. The corresponding unit prices for gasoline and LPG are $1.95/gallon ($0.52/liter) and $1.53/gallon ($0.40/liter) with yields of 55.1 and 9.3 gallons per U.S. ton of dry biomass (229.9 and 38.8 liters per metric tonne of dry biomass), respectively.

  13. Air quality in barns for milk-fed calves

    International Nuclear Information System (INIS)

    Lavoie, J.

    2007-01-01

    Seventy per cent of the veal produced in Canada comes from Quebec. This paper reported on the air quality in barns used for milk-fed calves. It is known that air quality inside livestock buildings has an impact on both workers and animals, particularly in winter when air circulation is reduced. In this study, air quality inside barns was studied during the winter, spring and summer. Three types of barns with 3 different types of ventilation typically found in Quebec were evaluated. These included those with preheated corridors, lateral air entries, and central chimneys. Gases were measured in order to determine concentrations and emissions of: ammonia (NH 3 ) which is toxic, colourless and flammable; hydrogen sulfide (H 2 S) which is very toxic, flammable; carbon dioxide (CO 2 ) which is colourless and odourless; nitrous oxide (N 2 O) which is colourless and flammable, but harmless to health in the short-term; carbon monoxide (CO) which is colourless, odourless and flammable; and methane (CH 4 ) which is the principal constituent released by animals, and is also colourless, odourless and extremely flammable. When exposed to air, both methane and carbon monoxide can produce an explosive mix especially in an enclosed area. Bacteria, mold, endotoxins, and dust are also present in barns. Samples of gases were analyzed with the help of different portable apparatuses. Results revealed that there are no significant problems with air quality in barns used for milk-fed calves in Quebec. It was determined that the inside temperature was appropriate even during summer periods, and although the relative humidity was higher than the recommended values for the care and handling of farm animals, it was still acceptable. In winter, ammonia was the only gas present in concentrations that reached values of weighted average exposure. Also, concentrations of bacteria were higher during winter. It was suggested that better air ventilation during the winter period would lower ammonia

  14. Parâmetros ruminais e síntese de proteína metabolizável em bovinos de corte sob suplementação com proteinados contendo diversos níveis de proteína bruta Ruminal fermentation characteristics and protein fraction effects on metabolizable protein synthesis of beef cattle fed different levels of crude protein

    Directory of Open Access Journals (Sweden)

    Luiz Orcirio Fialho de Oliveira

    2009-12-01

    Full Text Available Avaliaram-se os efeitos dos níveis de nitrogênio de suplementos proteicos sobre as concentrações de nitrogênio amoniacal (N-NH3 e ácidos graxos voláteis (AGV e o pH em bovinos de corte em pastagem de capim-marandu (Brachiaria brizantha, cv. Marandu. Foram realizadas estimativas da síntese microbiana, do aporte de proteína nãodegradável no rúmen (PNDR e proteína endógena e das suas contribuições no pool de proteína metabolizável (PM. Quatro bovinos Nelore com 395 ± 9 kg, fistulados no rúmen, foram utilizados nas medidas dos parâmetros ruminais e nas avaliações da degradabilidade, da cinética ruminal e das estimativas de síntese microbiana em um delineamento quadrado latino 4 ×4. Suplementos com 30, 40 ou 50% de proteína bruta (PB foram fornecidos na quantidade de 400 g/animal.dia para comparação a um grupo controle, sem suplementação proteica. Os animais foram mantidos em pastagens de Brachiaria brizantha, cv. Marandu, distribuídos em quatro piquetes com área de 1,0 ha cada, com oferta do suplemento e retirada das sobras, realizada diariamente. As concentrações de N-NH3 nos animais que receberam o suplemento com 50% PB foram superiores às observadas naqueles sob suplementação com 40% PB e no grupo controle, mas foram semelhantes às observadas no grupo sob suplementação com 30% PB. As concentrações de AGV no grupo sob suplementação com 30% PB foram superiores às observadas no grupo controle e semelhantes às obtidas com suplementação com 40 e 50% PB. O pH não diferiu entre os grupos. A estimativa de oferta de proteína microbiana e de PNDR foi maior para os animais sob suplementação com proteína em relação à observada no grupo controle.The effects of nitrogen levels of protein supplements were evaluated on the concentrations of ammonical nitrogen (N-NH3, volatile fatty acids (VFA's concentrations and pH in beef cattle grazing Brachiaria brizantha cv. Marandu. The microbial protein synthesis

  15. Influência do nitrogênio degradável no rúmen sobre a degradabilidade in situ, os parâmetros ruminais e a eficiência de síntese microbiana em novilhos alimentados com cana-de-açúcar Ruminal degradable nitrogen for steers fed sugar cane: in situ degradability, ruminal parameters and microbial synthesis efficiency

    Directory of Open Access Journals (Sweden)

    Roselene Nunes da Silveira

    2009-03-01

    Full Text Available Objetivou-se avaliar o efeito da deficiência de nitrogênio degradável no rúmen (NDR, utilizando como volumoso cana-de-açúcar suplementada com uréia, farelo de soja ou farelo de glúten de milho - 60, sobre a eficiência de síntese microbiana e a degradabilidade in situ da matéria seca (MS e da fibra em detergente neutro (FDN em novilhos mestiços. Utilizaram-se oito novilhos canulados no rúmen e duodeno, distribuídos em dois quadrados latinos 4 × 4 e alimentados com cana-de-açúcar e cana-de-açúcar suplementada com uréia, farelo de soja ou farelo de glúten de milho-60. O pH e a concentração de N-NH3 foram mensurados no fluido ruminal antes e 2, 4, 6 e 8 horas após o fornecimento da ração. Utilizou-se a fibra em detergente ácido indigestível como indicador de fluxo duodenal. A eficiência microbiana foi determinada pelas bases purinas.As fontes de proteína degradável no rúmen não influenciaram a degradabilidade da matéria seca, entretanto, o maior valor de degradabilidade efetiva da FDN foi obtido com a cana-de-açúcar com farelo de soja. O pH e a concentração de N-NH3 observados com todas as dietas foram adequados para o crescimento dos microrganismos ruminais. A deficiência de nitrogênio degradável no rúmen não influencia a síntese de proteína microbiana e a dinâmica de fase líquida.The objective of this work was to evaluate the ruminal degradable nitrogen (RDN deficit using as roughage sugar cane supplemented with urea, soybean meal, or corn gluten meal 60 on the microbial synthesis efficiency, in situ dry matter (DM and neutral detergent fiber (NDF degradability. The treatments were: sugar cane, sugar cane with urea, soybean meal or corn gluten meal 60. Eight rumen and duodenum cannulated steers were used and arranged according to two 4 × 4 Latin Squares. The pH and N-NH3 were determined in the ruminal fluid before and 2, 4, 6 and 8 hours after feeding. The duodenal flow was estimated by indigestible

  16. Large-scale production of alternative synthetic fuels from natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Dybkjaer, I.; Hansen, J.B. [Haldor Topsoee A/S, Lyngby (Denmark)

    1997-12-31

    Production of alternative liquid fuel from natural gas is an important option for the exploitation of remote gas fields. The products can be fuel methanol, synthetic gasoline and diesel fuel, and substitute fuels such as Dimethyl Ether (DME) which has been demonstrated to have attractive properties as a substitute diesel fuel. In each case the synthesis of the product requires preparation of synthesis gas with specified properties, and in all cases is the synthesis gas section the most important part of the plant both in terms of initial investments and in operating costs. Furthermore, proper integration of the synthesis gas section with other sections of the plant including the steam and power system is very important for the optimization of the overall process concept. The paper describes the various reforming technologies available for synthesis gas production - adiabatic pre-reforming, fired tubular reforming, secondary (oxygen-fired) reforming, and autothermal reforming - and the possibilities for manufacturing synthesis gas with different properties by these technologies alone or in combination. Large-scale manufacture of DME - the new alternative diesel fuel - from natural gas is described in some detail. The description covers the synthesis gas preparation, the product synthesis and purification, and the overall process economics. The properties of DME as a diesel fuel are briefly discussed. 22 refs.

  17. Coupling of glycerol processing with Fischer-Tropsch synthesis for production of liquid fuels

    DEFF Research Database (Denmark)

    Simonetti, D.A.; Rass-Hansen, Jeppe; Kunkes, E.L.

    2007-01-01

    Liquid alkanes can be produced directly from glycerol by an integrated process involving catalytic conversion to H-2/CO gas mixtures (synthesis gas) combined with Fischer-Tropsch synthesis. Synthesis gas can be produced at high rates and selectivities suitable for Fischer-Tropsch synthesis (H-2/CO......, acetone, and acetol. Fischer -Tropsch synthesis experiments at 548 K and 5 bar over a Ru-based catalyst reveal that water, ethanol, and acetone in the synthesis gas feed have only small effects, whereas acetol can participate in Fischer -Tropsch chain growth, forming pentanones, hexanones, and heptanones...... in the liquid organic effluent stream and increasing the selectivity to C5+ alkanes by a factor of 2 ( from 0.30 to 0.60). Catalytic conversion of glycerol and Fischer-Tropsch synthesis were coupled in a two-bed reactor system consisting of a Pt-Re/C catalyst bed followed by a Ru/TiO2 catalyst bed...

  18. 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)

  19. 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

  20. 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