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Sample records for catalytic hydrogen production

  1. Catalytic glycerol steam reforming for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-23

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

  2. Catalytic glycerol steam reforming for hydrogen production

    Science.gov (United States)

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

    2015-12-01

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

  3. Hydrogen production by catalytic gasification of cellulose in supercritical water

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Cellulose,one of the important components of biomass,was gasified in supercritical water to produce hydrogen-rich gas in an autoclave which was operated batch-wise under high-pressure.K2CO3 and Ca(OH)2 were selected as the catalysts (or promoters).The temperature was kept between 450℃ and 500℃ while pressure was maintained at 24-26 MPa.The reaction time was 20 min.Experimental results showed that the two catalysts had good catalytic effect and optimum amounts were observed for each catalyst.When 0.2 g K2CO3 was added,the hydrogen yield could reach 9.456 mol.kg-1 which was two times of the H2 amount produced without catalyst.When 1.6 g Ca(OH)2 was added,the H2 yield was K2CO3 as catalyst but is still 1.7 times that achieved without catalyst.Comparing with the results obtained using KaCO3 or Ca(OH)2 alone,the use of a combination of K2CO3 and Ca(OH)2 could increase the H2 yield by up to 2.5 times that without catalyst and 25% and 45% more than that obtained using K2CO3 and Ca(OH)2 alone,respectively.It was found that methane was the dominant product at relatively low temperature.When the temperature was increased,the methane reacts with water and is converted to hydrogen and carbon dioxide.

  4. HYDROGEN TRANSFER IN CATALYTIC CRACKING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

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

  5. Tunable Molecular MoS2 Edge-Site Mimics for Catalytic Hydrogen Production.

    Science.gov (United States)

    Garrett, Benjamin R; Polen, Shane M; Click, Kevin A; He, Mingfu; Huang, Zhongjie; Hadad, Christopher M; Wu, Yiying

    2016-04-18

    Molybdenum sulfides represent state-of-the-art, non-platinum electrocatalysts for the hydrogen evolution reaction (HER). According to the Sabatier principle, the hydrogen binding strength to the edge active sites should be neither too strong nor too weak. Therefore, it is of interest to develop a molecular motif that mimics the catalytic sites structurally and possesses tunable electronic properties that influence the hydrogen binding strength. Furthermore, molecular mimics will be important for providing mechanistic insight toward the HER with molybdenum sulfide catalysts. In this work, a modular method to tune the catalytic properties of the S-S bond in MoO(S2)2L2 complexes is described. We studied the homogeneous electrocatalytic hydrogen production performance metrics of three catalysts with different bipyridine substitutions. By varying the electron-donating abilities, we present the first demonstration of using the ligand to tune the catalytic properties of the S-S bond in molecular MoS2 edge-site mimics. This work can shed light on the relationship between the structure and electrocatalytic activity of molecular MoS2 catalysts and thus is of broad importance from catalytic hydrogen production to biological enzyme functions. PMID:27022836

  6. Catalytic combustor for hydrogen

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-01-01

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

  7. Catalytic heat exchangers for small-scale production of hydrogen - feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Silversand, F. [Catator AB, Lund (Sweden)

    2002-02-01

    A feasibility study concerning heat-exchanger reactors in small-scale production of hydrogen has been performed on the request of Svenskt Gastekniskt Center AB and SWEP International AB. The basic idea is to implement different catalysts into brazed plate-type heat exchangers. This can be achieved by installing catalytic cylinders in the inlet-and outlet ports of the heat exchangers or through treatment of the plates to render them catalytically active. It is also possible to sandwich catalytically active wire meshes between the plates. Experiments concerning steam reforming of methanol and methane have been performed in a micro-reactor to gather kinetic data for modelling purposes. Performance calculations concerning heat exchanger reactors have then been conducted with Catator's generic simulation code for catalytic reactors (CatalystExplorer). The simulations clearly demonstrate the technical performance of these reactors. Indeed, the production rate of hydrogen is expected to be about 10 nm{sup 3}/h per litre of heat exchanger. The corresponding value for a conventional steam-reforming unit is about 1 nm{sup 3}/h or less per litre of reactor volume. Also, the compactness and the high degree of integration together with the possibilities of mass production will give an attractive cost for such units. Depending on the demands concerning the purity of the hydrogen it is possible to add secondary catalytic steps like water-gas shifters, methanation and selective oxidation, into a one-train unit, i.e. to design an all-inclusive design. Such reactors can be used for the supply of hydrogen to fuel cells. The production cost for hydrogen can be cut by 60 - 70% through the utilisation of heat exchanger reactors instead of conventional electrolysis. This result is primarily a result of the high price for electricity compared to the feed stock prices in steam reforming. It is important to verify the performance calculations and the simulation results through

  8. Hydrogen Production From Crude Bio-oil and Biomass Char by Electrochemical Catalytic Reforming

    Institute of Scientific and Technical Information of China (English)

    Xing-long Li; Shen Ning; Li-xia Yuan; Quan-xin Li

    2011-01-01

    We reports an efficient approach for production of hydrogen from crude bio-oil and biomass char in the dual fixed-bed system by using the electrochemical catalytic reforming method.The maximal absolute hydrogen yield reached 110.9 g H2/kg dry biomass.The product gas was a mixed gas containing 72%H2,26%CO2,1.9%CO,and a trace amount of CH4.It was observed that adding biomass char (a by-product of pyrolysis of biomass) could remarkably increase the absolute H2 yield (about 20%-50%).The higher reforming temperature could enhance the steam reforming reaction of organic compounds in crude bio-oil and the reaction of CO and H2O.In addition,the CuZn-Al2O3 catalyst in the water-gas shift bed could also increase the absolute H2 yield via shifting CO to CO2.

  9. A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater

    Institute of Scientific and Technical Information of China (English)

    LI XiaoNian; ZHANG QunFeng; KONG LingNiao; XIANG YiZhi; JU YaoMing; WU XiaoQiong; FENG Feng; YUAN JunFeng; MA Lei; LU ChunShan

    2008-01-01

    A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater by aqueous phase reforming (APR) has been proposed. It is worthy of noting that this technique may be a potential way for the purification of refractory and highly toxic organics in water for hydrogen production. Hazardous organics (such as phenol, aniline, nitrobenzene, tetrahydrofuran (THF), toluene, N,N-dimethylformamide (DMF) and cyclohexanol) in water could be completely de-graded into H2 and CO2 with high selectivity over Raney Ni, and Sn-modified Raney Ni (Sn-Raney-Ni) or Pd/C catalyst under mild conditions. The experimental results operated in tubular and autoclave reactors, indicated that the degradation degree of organics and H2 selectivity could reach 100% under the optimal reaction conditions. The Sn-Raney-Ni (Sn/Ni=0.06) and Pd/C catalysts show better catalytic performances than the Raney Ni catalyst for the degradation of organics in water into H2 and CO2 by the aqueous phase reforming process.

  10. Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts

    OpenAIRE

    Irene Lock Sow Mei; S.S.M. Lock; Dai-Viet N. Vo; Bawadi Abdullah

    2016-01-01

    Hydrogen production from the direct thermo-catalytic decomposition of methane is a promising alternative for clean fuel production. However, thermal decomposition of methane can hardly be of any practical and empirical interest in the industry unless highly efficient and effective catalysts, in terms of both catalytic activity and operational lifetime have been developed. In this study, the effect of palladium (Pd) as a promoter onto Ni supported on alumina catalyst has been investigated by u...

  11. Co-production of hydrogen and carbon nanotubes on nickel foam via methane catalytic decomposition

    Science.gov (United States)

    Ping, Dan; Wang, Chaoxian; Dong, Xinfa; Dong, Yingchao

    2016-04-01

    The co-production of COx-free hydrogen and carbon nanotubes (CNTs) was achieved on 3-dimensional (3D) macroporous nickel foam (NF) via methane catalytic decomposition (MCD) over nano-Ni catalysts using chemical vapor deposition (CVD) technique. By a simple coating of a NiO-Al2O3 binary mixture sol followed by a drying-calcination-reduction treatment, NF supported composite catalysts (denoted as NiyAlOx/NF) with Al2O3 transition-layer incorporated with well-dispersed nano-Ni catalysts were successfully prepared. The effects of Ni loading, calcination temperature and reaction temperature on the performance for simultaneous production of COx-free hydrogen and CNTs were investigated in detail. Catalysts before and after MCD were characterized by XRD, TPR, SEM, TEM, TG and Raman spectroscopy technology. Results show that increasing Ni loading, lowering calcination temperature and optimizing MCD reaction temperature resulted in high production efficiency of COx-free H2 and carbon, but broader diameter distribution of CNTs. Through detailed parameter optimization, the catalyst with a Ni/Al molar ratio of 0.1, calcination temperature of 550 °C and MCD temperature of 650 °C was favorable to simultaneously produce COx-free hydrogen with a growth rate as high as 10.3% and CNTs with uniform size on NF.

  12. Production of natural antioxidants from vegetable oil deodorizer distillates: effect of catalytic hydrogenation.

    Science.gov (United States)

    Pagani, María Ayelén; Baltanás, Miguel A

    2010-02-01

    Natural tocopherols are one of the main types of antioxidants found in living creatures, but they also have other critical biological functions. The biopotency of natural (+)-alpha-tocopherol (RRR) is 36% higher than that of the synthetic racemic mixture and 300% higher than the SRR stereoisomer. Vegetable oil deodorizer distillates (DD) are an excellent source of natural tocopherols. Catalytic hydrogenation of DD preconcentrates has been suggested as a feasible route for recovery of tocopherols in high yield. However, it is important to know whether the hydrogenation operation, as applied to these tocopherol-rich mixtures, is capable of preserving the chiral (RRR) character, which is critical to its biopotency. Fortified (i.e., (+)-alpha-tocopherol enriched) sunflower oil and methyl stearate, as well as sunflower oil DD, were fully hydrogenated using commercial Ni and Pd catalysts (120-180 degrees C; 20-60 psig). Products were analyzed by chiral HPLC. Results show that the desired chiral configuration (RRR) is fully retained. Thus, the hydrogenation route can be safely considered as a valid alternative for increasing the efficiency of tocopherol recovery processes from DDs while preserving their natural characteristics.

  13. A novel liquid system of catalytic hydrogenation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On the basis that endothermic aqueous-phase reforming of oxygenated hydrocarbons for H2 production and exothermic liquid phase hydrogenation of organic compounds are carried out under extremely close conditions of temperature and pressure over the same type of catalyst, a novel liquid system of catalytic hydrogenation has been proposed, in which hydrogen produced from aqueous-phase reforming of oxygenated hydrocarbons is in situ used for liquid phase hydrogenation of organic compounds. The usage of active hydrogen generated from aqueous-phase reforming of oxygenated hydrocarbons for liquid catalytic hydrogenation of organic compounds could lead to increasing the selectivity to H2 in the aqueous-phase reforming due to the prompt removal of hydrogen on the active centers of the catalyst. Meanwhile, this novel liquid system of catalytic hydrogenation might be a potential method to improve the selectivity to the desired product in liquid phase catalytic hydrogenation of organic compounds. On the other hand, for this novel liquid system of catalytic hydrogenation, some special facilities for H2 generation, storage and transportation in traditional liquid phase hydrogenation industry process are yet not needed. Thus, it would simplify the working process of liquid phase hydrogenation and increase the energy usage and hydrogen productivity.

  14. Catalytic on-board hydrogen production from methanol and ammonia for mobile application

    Energy Technology Data Exchange (ETDEWEB)

    Soerijanto, H.

    2008-08-15

    This PhD thesis deals with the catalytic hydrogen production for mobile application, for example for the use in fuel cells for electric cars. Electric powered buses with fuel cells as driving system are well known, but the secure hydrogen storage in adequate amounts for long distance drive is still a topic of discussion. Methanol is an excellent hydrogen carrier. First of all it has a high H:C ratio and therefore a high energy density. Secondly the operating temperature of steam reforming of methanol is comparatively low (250 C) and there is no risk of coking since methanol has no C-C bond. Thirdly methanol is a liquid, which means that the present gasoline infrastructure can be used. For the further development of catalysts and for the construction of a reformer it is very important to characterize the catalysts very well. For the dimensioning and the control of an on-board production of hydrogen it is essential to draw accurately on the thermodynamic, chemical and kinetic data of the reaction. At the first part of this work the mesoporous Cu/ZrO{sub 2}/CeO{sub 2}-catalysts with various copper contents were characterized and their long-term stability and selectivity were investigated, and the kinetic data were determined. Carbon monoxide is generated by reforming of carbon containing material. This process is undesired since CO poisons the Pt electrode of the fuel cell. The separation of hydrogen by metal membranes is technically feasible and a high purity of hydrogen can be obtained. However, due to their high density this procedure is not favourable because of its energy loss. In this study a concept is presented, which enables an autothermal mode by application of ceramic membrane and simultaneously could help to deal with the CO problem. The search for an absolutely selective catalyst is uncertain. The production of CO can be neither chemically nor thermodynamically excluded, if carbon is present in the hydrogen carrier. Since enrichment or separation are

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-01-15

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

  16. Effect of Catalytic Cylinders on Autothermal Reforming of Methane for Hydrogen Production in a Microchamber Reactor

    Directory of Open Access Journals (Sweden)

    Yunfei Yan

    2014-01-01

    Full Text Available A new multicylinder microchamber reactor is designed on autothermal reforming of methane for hydrogen production, and its performance and thermal behavior, that is, based on the reaction mechanism, is numerically investigated by varying the cylinder radius, cylinder spacing, and cylinder layout. The results show that larger cylinder radius can promote reforming reaction; the mass fraction of methane decreased from 26% to 21% with cylinder radius from 0.25 mm to 0.75 mm; compact cylinder spacing corresponds to more catalytic surface and the time to steady state is decreased from 40 s to 20 s; alteration of staggered and aligned cylinder layout at constant inlet flow rates does not result in significant difference in reactor performance and it can be neglected. The results provide an indication and optimize performance of reactor; it achieves higher conversion compared with other reforming reactors.

  17. Hydrogen production in a zigzag and straight catalytic wall coated micro channel reactor by CFD modeling

    Energy Technology Data Exchange (ETDEWEB)

    Fazeli, Ali; Behnam, Mohsen [Gas Research Division, Research Institute of Petroleum Industry (RIPI), P.O. Box 14665-137, Tehran (Iran)

    2010-09-15

    Hydrogen production from steam reforming of methanol for fuel cell application was modeled in a wall coated micro channel reactor by CFD approach. Heat of steam reforming (SR) was supplied from catalytic total oxidation (TOX) of methanol on Cu/ZnO/Al{sub 2}O{sub 3} catalyst and Heat conducts from TOX to SR zone through Steel divider wall between two channels. Heat integration was compared in zigzag and straight geometry of microreactor by CFD modeling. The model is two dimensional, steady state and containing five zones: TOX fluid, TOX catalyst layer, steel wall of the channel, SR catalyst layer and SR fluid. Set of partial differential equations (PDEs) including x and y momentum balance, continuity, partial mass balances and energy balance was solved by finite volume method. Stiff reaction rates were considered for methanol total oxidation (TOX), methanol steam reforming (SR), water gas shift (WGS) and methanol decomposition (MD) reactions. The results show that zigzag geometry is better than straight one because heat and mass transfer in zigzag reactor are more than straight. Conversion of methanol in zigzag geometry is greater than straight one. In the outlet of zigzag micro channels, carbon monoxide selectivity is less and hydrogen mole fraction is more than straight one. (author)

  18. Catalytic Metal Free Production of Large Cage Structure Carbon Particles: A Candidate for Hydrogen Storage

    Science.gov (United States)

    Kimura, Yuki; Nuth, Joseph A., III; Ferguson, Frank T.

    2005-01-01

    We will demonstrate that carbon particles consisting of large cages can be produced without catalytic metal. The carbon particles were produced in CO gas as well as by introduction of 5% methane gas into the CO gas. The gas-produced carbon particles were able to absorb approximately 16.2 wt% of hydrogen. This value is 2.5 times higher than the 6.5 wt% goal for the vehicular hydrogen storage proposed by the Department of Energy in the USA. Therefore, we believe that this carbon particle is an excellent candidate for hydrogen storage for fuel cells.

  19. Evidence of catalytic production of hot hydrogen in rf generated hydrogen/argon plasmas

    CERN Document Server

    Phillips, J; Akhtar, K; Dhandapani, B; Mills, R; Phillips, Jonathan; Chen, Chun-Ku; Akhtar, Kamran; Dhandapani, Bala; Mills, Randell

    2005-01-01

    In this paper the selective broadening of the atomic hydrogen lines in pure H2 and Ar/H2 mixtures in a large 'GEC' cell (36 cm length_ 14 cm ID) was mapped as a function of position, H2/Ar ratio, time, power, and pressure. Several observations regarding the selective line broadening were particularly notable as they are unanticipated on the basis of earlier models. First, the anomalous broadening of the Balmer lines was found to exist throughout the plasma, and not just in the region between the electrodes. Second, the broadening was consistently a complex function of the operating parameters particularly gas composition (highest in pure H2), position, power, time and pressure. Clearly not anticipated by earlier models were the findings that under some conditions the highest concentration of 'hot' (>10 eV) hydrogen was found at the entry end, and not in the high field region between the electrodes and that in other conditions, the hottest H was at the (exit) pump (also grounded electrode) end. Third, excitati...

  20. Production of hydrogen from biomass by catalytic steam reforming of fast pyrolysis oil

    Energy Technology Data Exchange (ETDEWEB)

    Czernik, S.; Wang, D.; Chornet, E. [National Renewable Energy Lab., Golden, CO (United States). Center for Renewable Chemical Technologies and Materials

    1998-08-01

    Hydrogen is the prototype of the environmentally cleanest fuel of interest for power generation using fuel cells and for transportation. The thermochemical conversion of biomass to hydrogen can be carried out through two distinct strategies: (a) gasification followed by water-gas shift conversion, and (b) catalytic steam reforming of specific fractions derived from fast pyrolysis and aqueous/steam processes of biomass. This paper presents the latter route that begins with fast pyrolysis of biomass to produce bio-oil. This oil (as a whole or its selected fractions) can be converted to hydrogen via catalytic steam reforming followed by a water-gas shift conversion step. Such a process has been demonstrated at the bench scale using model compounds, poplar oil aqueous fraction, and the whole pyrolysis oil with commercial Ni-based steam reforming catalysts. Hydrogen yields as high as 85% have been obtained. Catalyst initial activity can be recovered through regeneration cycles by steam or CO{sub 2} gasification of carbonaceous deposits.

  1. Hydrogen production from catalytic reforming of the aqueous fraction of pyrolysis bio-oil with modified Ni-Al catalysts

    OpenAIRE

    D. Yao; Wu, C.; Yang, H; Hu, Q.; Nahil, MA; H Chen; Williams, PT

    2014-01-01

    Hydrogen production from renewable resources has received extensive attention recently for a sustainable and renewable future. In this study, hydrogen was produced from catalytic steam reforming of the aqueous fraction of crude bio-oil, which was obtained from pyrolysis of biomass. Five Ni-Al catalysts modified with Ca, Ce, Mg, Mn and Zn were investigated using a fixed-bed reactor. Optimized process conditions were obtained with a steam reforming temperature of 800 °C and a steam to carbon ra...

  2. Catalytic Lignin Valorization Process for the Production of Aromatic Chemicals and Hydrogen

    NARCIS (Netherlands)

    Zakzeski, J.; Jongerius, A.L.; Bruijnincx, P.C.A.; Weckhuysen, B.M.

    2012-01-01

    With dwindling reserves of fossil feedstock as a resource for chemicals production, the fraction of chemicals and energy supplied by alternative, renewable resources, such as lignin, can be expected to increase in the foreseeable future. Here, we demonstrate a catalytic process to valorize lignin (e

  3. Maximizing renewable hydrogen production from biomass in a bio/catalytic refinery

    DEFF Research Database (Denmark)

    Westermann, Peter; Jørgensen, Betina; Lange, L.;

    2007-01-01

    concept is the high versatility with respect to input of different types of biological wastes, which are abundant and cheap residues from agricultural production. Also the concept leaves the opportunity to optimize the microbiological and catalytic processes to meet specific needs for fuel flexibility....

  4. Polarographic catalytic wave of hydrogen--Parallel catalytic hydrogen wave of bovine serum albumin in thepresence of oxidants

    Institute of Scientific and Technical Information of China (English)

    GUO; Wei(过玮); LIU; Limin(刘利民); LIN; Hong(林洪); SONG; Junfeng(宋俊峰)

    2002-01-01

    A polarographic catalytic hydrogen wave of bovine serum albumin (BSA) at about -1.80 V (vs. SCE) in NH4Cl-NH3@H2O buffer is further catalyzed by such oxidants as iodate, persulfate and hydrogen peroxide, producing a kinetic wave. Studies show that the kinetic wave is a parallel catalytic wave of hydrogen, which resulted from that hydrogen ion is electrochemically reduced and chemically regenerated through oxidation of its reduction product, atomic hydrogen, by oxidants mentioned above. It is a new type of poralographic catalytic wave of protein, which is suggested to be named as a parallel catalytic hydrogen wave.

  5. Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts

    Directory of Open Access Journals (Sweden)

    Irene Lock Sow Mei

    2016-08-01

    Full Text Available Hydrogen production from the direct thermo-catalytic decomposition of methane is a promising alternative for clean fuel production. However, thermal decomposition of methane can hardly be of any practical and empirical interest in the industry unless highly efficient and effective catalysts, in terms of both catalytic activity and operational lifetime have been developed. In this study, the effect of palladium (Pd as a promoter onto Ni supported on alumina catalyst has been investigated by using co-precipitation technique. The introduction of Pd promotes better catalytic activity, operational lifetime and thermal stability of the catalyst. As expected, highest methane conversion was achieved at reaction temperature of 800 °C while the bimetallic catalyst (1 wt.% Ni -1wt.% Pd/Al2O3 gave the highest methane conversion of 70% over 15 min of time-on-stream (TOS. Interestingly, the introduction of Pd as promoter onto Ni-based catalyst also has a positive effect on the operational lifetime and thermal stability of the catalyst as the methane conversion has improved significantly over 240 min of TOS. Copyright © 2016 BCREC GROUP. All rights reserved Received: 21st January 2016; Revised: 6th February 2016; Accepted: 6th March 2016 How to Cite: Mei, I.L.S., Lock, S.S.M., Vo, D.V.N., Abdullah, B. (2016. Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2: 191-199 (doi:10.9767/bcrec.11.2.550.191-199 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.550.191-199

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  7. Effect of Catalytic Cylinders on Autothermal Reforming of Methane for Hydrogen Production in a Microchamber Reactor

    OpenAIRE

    Yunfei Yan; Hongliang Guo; Li Zhang; Junchen Zhu; Zhongqing Yang; Qiang Tang; Xin Ji

    2014-01-01

    A new multicylinder microchamber reactor is designed on autothermal reforming of methane for hydrogen production, and its performance and thermal behavior, that is, based on the reaction mechanism, is numerically investigated by varying the cylinder radius, cylinder spacing, and cylinder layout. The results show that larger cylinder radius can promote reforming reaction; the mass fraction of methane decreased from 26% to 21% with cylinder radius from 0.25 mm to 0.75 mm; compact cylinder spaci...

  8. Production of activated carbon and its catalytic application for oxidation of hydrogen sulphide

    Science.gov (United States)

    Azargohar, Ramin

    Hydrogen sulphide is an environmentally hazardous gas which is present in many gas streams associated with oil and gas industry. Oxidation of H 2S to sulphur in air produces no bulky or waste material and requires no further purification. Activated carbon is known as a catalyst for this reaction. In this research, a coal-based precursor (luscar char) and a biomass-based precursor (biochar) were used for production of activated carbons by two common methods of activation: physical and chemical activation in which steam and potassium hydroxide (KOH), respectively, were used. Experiments were designed by the statistical central composite design method. Two models were developed for the BET surface area and reaction yield of each activation process. These models showed the effects of operating conditions, such as activation temperature, mass ratio of activating agent to precursor, activation time, and nitrogen flowrate on the BET surface area and reaction yield for each activation method for each precursor. The optimum operating conditions were calculated using these models to produce activated carbons with relatively large BET surface area (> 500 m2/g) and high reaction yield (> 50 wt %). The BET surface area and reaction yield for activated carbons produced at optimum operating conditions showed maximum 7 and 7.4% difference, respectively, comparing to the values predicted by models. The activated carbons produced at optimum operating conditions were used as the base catalysts for the direct oxidation of 1 mol % hydrogen sulphide in nitrogen to sulphur at the temperature range of 160-205°C and pressure of 700 kPa. Originally activated carbons showed a good potential for oxidation of hydrogen sulphide by their selectivity for sulphur product and low amount of sulphur dioxide production. To improve the performance of steam-activated carbons, the catalysts were modified by acid-treatment followed by thermal desorption. This method increased the break-through times for

  9. Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-09-01

    This 2-page fact sheet provides a brief introduction to hydrogen production technologies. Intended for a non-technical audience, it explains how different resources and processes can be used to produce hydrogen. It includes an overview of research goals as well as “quick facts” about hydrogen energy resources and production technologies.

  10. Production of hydrogen, liquid fuels, and chemicals from catalytic processing of bio-oils

    Science.gov (United States)

    Huber, George W; Vispute, Tushar P; Routray, Kamalakanta

    2014-06-03

    Disclosed herein is a method of generating hydrogen from a bio-oil, comprising hydrogenating a water-soluble fraction of the bio-oil with hydrogen in the presence of a hydrogenation catalyst, and reforming the water-soluble fraction by aqueous-phase reforming in the presence of a reforming catalyst, wherein hydrogen is generated by the reforming, and the amount of hydrogen generated is greater than that consumed by the hydrogenating. The method can further comprise hydrocracking or hydrotreating a lignin fraction of the bio-oil with hydrogen in the presence of a hydrocracking catalyst wherein the lignin fraction of bio-oil is obtained as a water-insoluble fraction from aqueous extraction of bio-oil. The hydrogen used in the hydrogenating and in the hydrocracking or hydrotreating can be generated by reforming the water-soluble fraction of bio-oil.

  11. DESIGN NOTE: A compact catalytic converter for the production of para-hydrogen

    Science.gov (United States)

    Juarez, A. M.; Cubric, D.; King, G. C.

    2002-05-01

    The design and operation of a compact converter to produce a constant flow of para-hydrogen from normal hydrogen is described. The converter features a paramagnetic compound (nickel sulfate) that catalyses the conversion of ortho- to para-hydrogen at temperatures of 14-21 K. The converter has been tested by measuring rotationally resolved photoelectron spectra in the para-hydrogen produced. The percentage of the para-hydrogen species in the converted gas was determined to be >97%.

  12. Hydrogen Production by Thermo-catalytic Decomposition of Natural Gas: Carbonaceous Catalysts

    International Nuclear Information System (INIS)

    TCD of CH4 using different kinds of carbon catalyst, activated carbons (AC) and carbon blacks (CB) have been studied. AC showed an acceptable initial reaction rate but they become rapidly deactivated, while CB with high surface area provided more stable and sustainable hydrogen production. Regeneration of the carbonaceous catalysts after deactivation, using CO2 as activating agent has been studied. A commercial active carbon has been selected for the regeneration tests. The optimum operation conditions for the catalysts regeneration have been studied, attending to the burn off of the catalysts during the regeneration, which is important for the self-consistence of the process, and the recovering in the surface area, which is one of the most important factors affecting the activity of these catalysts. (authors)

  13. Hydrogen production by catalytic decomposition of methane using a Fe-based catalyst in a fluidized bed reactor

    Institute of Scientific and Technical Information of China (English)

    D.Torres; S.de Llobet; J.L.Pinilla; M.J.Lázaro; I.Suelves; R.Moliner

    2012-01-01

    Catalytic decomposition of methane using a Fe-based catalyst for hydrogen production has been studied in this work.A Fe/Al2O3 catalyst previously developed by our research group has been tested in a fluidized bed reactor (FBR).A parametric study of the effects of some process variables,including reaction temperature and space velocity,is undertaken.The operating conditions strongly affect the catalyst performance.Methane conversion was increased by increasing the temperature and lowering the space velocity.Using temperatures between 700 and 900 ℃ and space velocities between 3 and 6 LN/(gcat·h),a methane conversion in the range of 25%-40% for the gas exiting the reactor could be obtained during a 6 h run.In addition,carbon was deposited in the form of nanofilaments (chain like nanofibers and multiwall nanotubes) with similar properties to those obtained in a fixed bed reactor.

  14. Process concept for hydrogen production by catalytic conversion of defined kerosene fractions; Verfahrenskonzept zur Wasserstofferzeugung durch katalytische Umwandlung definierter Kerosinfraktionen

    Energy Technology Data Exchange (ETDEWEB)

    Frick, Viktoria

    2011-06-15

    The innovative process concept presented in this thesis for on-board hydrogen generation from kerosene for power generation aboard aircrafts by fuel cell systems exhibits significant advantages on reaction and process level compared to the hydrogen production via reforming. It includes the separation of a defined low-sulphur fraction from kerosene via rectification or crystallization which is subsequently converted catalytically to hydrogen. To investigate thermal management and process integration of the overall system four possible process concepts have been identified and their overall efficiency has been compared to a reference concept by process simulation. The key process parameters for fractionation were derived from experimental investigations. The processes with dehydrogenation resulted in the highest hydrogen yield and an overall electrical efficiency of 43 % could be achieved in combination with crystallization, which is a significant increase against the reference concept. Taking aircraft specific boundary conditions into account this process concept has been derived as the lead concept. Moreover, it avoids the unsolved until now problems connected to undesirable production of NO{sub x} and CO. [German] Das im Rahmen dieser Arbeit erarbeitete innovative Prozesskonzept zur on-board Wasserstofferzeugung aus Kerosin fuer den Betrieb von Brennstoffzellensystemen zur Energieversorgung im Flugzeug weist erhebliche reaktions- und verfahrenstechnische Vorteile gegenueber der Wasserstofferzeugung mittels Reformierung auf. Es beinhaltet die Abtrennung, einer definierten schwefelarmen Fraktion des Kerosins mittels Rektifikation oder Kristallisation. Diese wird in einem nachfolgenden Schritt katalytisch zu Wasserstoff umgewandelt. Zur Untersuchung der Waermeintegration und Prozessfuehrung im Gesamtsystem wurden vier moegliche Verfahrenskonzepte identifiziert und deren Systemwirkungsgrade mittels Prozesssimulation mit einem Referenzkonzept verglichen. Die

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

    International Nuclear Information System (INIS)

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

  16. Photo-catalytic hydrogen production over Fe{sub 2}O{sub 3} based catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Boudjemaa, A. [Technical and Scientific Research Centre of Physico-chemistry Analysis (CRAPC), BP 248, RP 16004, Algiers (Algeria); Laboratory of Chemistry of Natural Gas, Faculty of Chemistry (USTHB) BP 32, 16111 Algiers (Algeria); Trari, M. [Laboratory of Storage and Valorization of Renewable Energies, Faculty of Chemistry (USTHB) BP 32, 16111 Algiers (Algeria)

    2010-08-15

    The hydrogen photo-evolution was successfully achieved in aqueous (Fe{sub 1-x}Cr{sub x}){sub 2}O{sub 3} suspensions (0 {<=} x {<=} 1). The solid solution has been prepared by incipient wetness impregnation and characterized by X-ray diffraction, BET, transport properties and photo-electrochemistry. The oxides crystallize in the corundum structure, they exhibit n-type conductivity with activation energy of {proportional_to}0.1 eV and the conduction occurs via adiabatic polaron hops. The characterization of the band edges has been studied by the Mott Schottky plots. The onset potential of the photo-current is {proportional_to}0.2 V cathodic with respect to the flat band potential, implying a small existence of surface states within the gap region. The absorption of visible light promotes electrons into (Fe{sub 1-x}Cr{sub x}){sub 2}O{sub 3}-CB with a potential ({proportional_to}-0.5 V{sub SCE}) sufficient to reduce water into hydrogen. As expected, the quantum yield increases with decreasing the electro affinity through the substitution of iron by the more electropositive chromium which increases the band bending at the interface and favours the charge separation. The generated photo-voltage was sufficient to promote simultaneously H{sub 2}O reduction and SO{sub 3}{sup 2-} oxidation in the energetically downhill reaction (H{sub 2}O + SO{sub 3}{sup 2-} {yields} H{sub 2} + SO{sub 4}{sup 2-}, {delta}G = -17.68 kJ mol{sup -1}). The best activity occurs over Fe{sub 1.2}Cr{sub 0.8}O{sub 3} in SO{sub 3}{sup 2-} (0.1 M) solution with H{sub 2} liberation rate of 21.7 {mu}mol g{sup -1} min{sup -1} and a quantum yield 0.06% under polychromatic light. Over time, a pronounced deceleration occurs, due to the competitive reduction of the end product S{sub 2}O{sub 6}{sup 2-}. (author)

  17. Experimental and Numerical Evaluation of the By-Pass Flow in a Catalytic Plate Reactor for Hydrogen Production

    DEFF Research Database (Denmark)

    Sigurdsson, Haftor Örn; Kær, Søren Knudsen

    2011-01-01

    Numerical and experimental study is performed to evaluate the reactant by-pass flow in a catalytic plate reactor with a coated wire mesh catalyst for steam reforming of methane for hydrogen generation. By-pass of unconverted methane is evaluated under different wire mesh catalyst width to reactor...

  18. Progress in Catalytic Membrane Reactors for High Purity Hydrogen Production%膜催化反应器及其制氢技术的研究进展

    Institute of Scientific and Technical Information of China (English)

    闫云飞; 张力; 李丽仙; 唐强

    2011-01-01

    As a kind of ideal fuel for fuel cell, hydrogen must be satisfied with the enough high purity. To produce high purity hydrogen at a low cost and large scale method has become a key research focus in the industrialization of fuel-cell technology. The membrane catalytic technology with catalysis and separation dual functions has been developed in recent years, which is a good method to produce high purity hydrogen. Based on the latest developments in the membrane catalytic reaction fields, the advantages, composition and type of membrane catalytic reactor are summarized. The preparation techniques, advantages and classification of inorganic membrane materials are described. Especially, the progress and application for high purity hydrogen production are reviewed in three kinds of catalytic membrane reactors, including oxygen-permeable membrane reactor, hydrogen-permeation membrane reactor and double-membranes reactor. The existing problems of catalytic membrane and membrane catalytic reactor in the industrialization process of hydrogen production using the membrane catalytic technology are also discussed. Additionally, the prospects of membrane catalytic reactors for hydrogen production is proposed.%燃料电池对其理想燃料氢气的纯度要求极高,如何低成本、大规模制取高纯氢气己成为燃料电池技术实现工业化的一个关键问题和研究热点.近年发展起来的兼具催化与分离双重功能的膜催化反应技术是实现制取高纯氢气的一个有效途径.本文结合膜催化反应领域的最新进展,综述了膜催化反应器的优点、组成、类型;介绍了无机膜材料的优点、分类及制备技术;详细综述了透氧膜催化反应器、透氢膜催化反应器及双膜催化反应器在制氢过程中的研究进展和应用,指出了膜催化反应制氢技术在工业化发展过程中存在的问题及应用前景.

  19. Catalytic hydrogenation of carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Wayland, B.B.

    1992-12-01

    This project is focused on developing strategies to accomplish the reduction and hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. Our approaches to this issue are based on the recognition that rhodium macrocycles have unusually favorable thermodynamic values for producing a series of intermediate implicated in the catalytic hydrogenation of CO. Observations of metalloformyl complexes produced by reactions of H{sub 2} and CO, and reductive coupling of CO to form metallo {alpha}-diketone species have suggested a multiplicity of routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in constructing energy profiles for a variety of potential pathways, and these schemes are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Variation of the electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Emerging knowledge of the factors that contribute to M-H, M-C and M-O bond enthalpies is directing the search for ligand arrays that will expand the range of metal species that have favorable thermodynamic parameters to produce the primary intermediates for CO hydrogenation. Studies of rhodium complexes are being extended to non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics. Multifunctional catalyst systems designed to couple the ability of rhodium complexes to produce formyl and diketone intermediates with a second catalyst that hydrogenates these imtermediates are promising approaches to accomplish CO hydrogenation at mild conditions.

  20. Chemistry - Toward efficient hydrogen production at surfaces

    DEFF Research Database (Denmark)

    Nørskov, Jens Kehlet; Christensen, Claus H.

    2006-01-01

    Calculations are providing a molecular picture of hydrogen production on catalytic surfaces and within enzymes, knowledge that may guide the design of new, more efficient catalysts for the hydrogen economy.......Calculations are providing a molecular picture of hydrogen production on catalytic surfaces and within enzymes, knowledge that may guide the design of new, more efficient catalysts for the hydrogen economy....

  1. Green diesel production via catalytic hydrogenation/decarboxylation of triglycerides and fatty acids of vegetable oil and brown grease

    Science.gov (United States)

    Sari, Elvan

    than activated carbon itself for both decarboxylation of oleic acid and hydrogenation of alkenes. In an additional effort to reduce Pd amount in the catalyst, Pd2Co/C catalysts with various Pd content were prepared and the catalytic activity study showed that 0.5 wt% Pd2Co/C catalyst performs even better than a 5 wt% Pd/C catalyst. Pd and Co alloys were very well dispersed and formed fine clusters, which led to a higher active metal surface area and hence favored the decarboxylation of oleic acid. This study showed that an alloy of Pd on carbon with a significantly low Pd content is much more active and selective to diesel hydrocarbons production from an unsaturated fatty acid in super-critical water and may be regarded as a prospective feasible decarboxylation catalyst for the removal of oxygen from vegetable oil/animal fat without the need of additional hydrogen.

  2. Ammonia Decomposition for Hydrogen Production in Catalytic Microchannels with Slip/Jump Effects

    Directory of Open Access Journals (Sweden)

    Azad Qazi Zade

    2015-01-01

    Full Text Available The rarefaction effects on the catalytic decomposition of NH3 in ruthenium–coated planar microchannels is numerically simulated in the Knudsen number range 0.015-0.03. A colocated finite–volume method is used to solve the governing equations. A concentration jump model derived from the kinetic theory of gases is employed to account for the concentration discontinuity at the reactive walls. A detailed surface reaction mechanism for ammonia decomposition on ruthenium along with a multi-component species diffusion model are used to study the effects of concentration jump coupled with velocity slip and temperature jump on the walls. The velocity-slip, temperature-jump and concentration-jump boundary conditions have miscellaneous effects on flow, temperature and species concentration fields. The results suggest that the velocity-slip boundary condition only slightly influences the species distribution at the edge of the Knudsen layer as well as inside the channel, while the temperature-jump boundary condition affects the heat and mass transfer characteristics the most. The concentration-jump effect, on the other hand, can counter balance the temperature-jump effects in some cases.

  3. Molecular hydrogen and catalytic combustion in the production of hyperpolarized 83Kr and 129Xe MRI contrast agents

    Science.gov (United States)

    Rogers, Nicola J.; Hill-Casey, Fraser; Stupic, Karl F.; Six, Joseph S.; Lesbats, Clémentine; Rigby, Sean P.; Fraissard, Jacques; Pavlovskaya, Galina E.; Meersmann, Thomas

    2016-03-01

    Hyperpolarized (hp) 83Kr is a promising MRI contrast agent for the diagnosis of pulmonary diseases affecting the surface of the respiratory zone. However, the distinct physical properties of 83Kr that enable unique MRI contrast also complicate the production of hp 83Kr. This work presents a previously unexplored approach in the generation of hp 83Kr that can likewise be used for the production of hp 129Xe. Molecular nitrogen, typically used as buffer gas in spin-exchange optical pumping (SEOP), was replaced by molecular hydrogen without penalty for the achievable hyperpolarization. In this particular study, the highest obtained nuclear spin polarizations were P = 29% for 83Kr and P = 63% for 129Xe. The results were reproduced over many SEOP cycles despite the laser-induced on-resonance formation of rubidium hydride (RbH). Following SEOP, the H2 was reactively removed via catalytic combustion without measurable losses in hyperpolarized spin state of either 83Kr or 129Xe. Highly spin-polarized 83Kr can now be purified for the first time, to our knowledge, to provide high signal intensity for the advancement of in vivo hp 83Kr MRI. More generally, a chemical reaction appears as a viable alternative to the cryogenic separation process, the primary purification method of hp 129Xe for the past 2 1/2 decades. The inherent simplicity of the combustion process will facilitate hp 129Xe production and should allow for on-demand continuous flow of purified and highly spin-polarized 129Xe.

  4. Hydrogen production by steam reforming of bio-alcohols. The use of conventional and membrane-assisted catalytic reactors

    Energy Technology Data Exchange (ETDEWEB)

    Seelam, P. K.

    2013-11-01

    The energy consumption around the globe is on the rise due to the exponential population growth and urbanization. There is a need for alternative and non-conventional energy sources, which are CO{sub 2}-neutral, and a need to produce less or no environmental pollutants and to have high energy efficiency. One of the alternative approaches is hydrogen economy with the fuel cell (FC) technology which is forecasted to lead to a sustainable society. Hydrogen (H{sub 2}) is recognized as a potential fuel and clean energy carrier being at the same time a carbon-free element. Moreover, H{sub 2} is utilized in many processes in chemical, food, metallurgical, and pharmaceutical industry and it is also a valuable chemical in many reactions (e.g. refineries). Non-renewable resources have been the major feedstock for H{sub 2} production for many years. At present, {approx}50% of H{sub 2} is produced via catalytic steam reforming of natural gas followed by various down-stream purification steps to produce {approx}99.99% H{sub 2}, the process being highly energy intensive. Henceforth, bio-fuels like biomass derived alcohols (e.g. bio-ethanol and bio-glycerol), can be viable raw materials for the H{sub 2} production. In a membrane based reactor, the reaction and selective separation of H{sub 2} occur simultaneously in one unit, thus improving the overall reactor efficiency. The main motivation of this work is to produce H{sub 2} more efficiently and in an environmentally friendly way from bio-alcohols with a high H{sub 2} selectivity, purity and yield. In this thesis, the work was divided into two research areas, the first being the catalytic studies using metal decorated carbon nanotube (CNT) based catalysts in steam reforming of ethanol (SRE) at low temperatures (<450 deg C). The second part was the study of steam reforming (SR) and the water-gas-shift (WGS) reactions in a membrane reactor (MR) using dense and composite Pd-based membranes to produce high purity H{sub 2}. CNTs

  5. Catalytic hydrogen production over RhPd/CeO2 catalysts and CO purification over Au/TiO2 catalysts

    OpenAIRE

    Jiménez Divins, Núria

    2015-01-01

    La consulta íntegra de la tesi, inclosos els articles no comunicats públicament per drets d'autor, es pot realitzar prèvia petició a l'Arxiu UPC This Thesis focuses on the study of the catalytic production of hydrogen from a biofuel, namely the bioethanol. It also studies the subsequent purification of pre-cleaned reformate streams. The end use of the hydrogen produced is to feed fuel cells to power portable and mobile applications. In this Thesis, two types of catalysts have been develope...

  6. Hydrogen production from catalytic decomposition of methane; Produccion de hidrogeno a partir de la descomposicion termica catalitica del biogas de digestion anaerobia

    Energy Technology Data Exchange (ETDEWEB)

    Belsue Echevarria, M.; Etxebeste Juarez, O.; Perez Gil, S.

    2002-07-01

    The need of substitution of part of the energy obtained from fossil fuels instead of energy from renewable sources, together with the minimal emissions of CO{sub ''} and CO that are expected with these technologies, make renewable sources a very attractive predecessor for the production of hydrogen. In this situation, a usable source for hydrogen production is the biogas achieved by means of technologies like the anaerobic digestion of different kinds of biomass (MSW, sewage sludge, stc.). In this article we suggest the Thermal Catalytic Decomposition of the methane contained in this biogas, after separation of pollutants like CO{sub ''}, H{sub 2}S. steam. This technology will give hydrogen, usable in fuel cells, and nanoestructured carbon as products. (Author) 7 refs.

  7. Advanced Catalytic Hydrogenation Retrofit Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Reinaldo M. Machado

    2002-08-15

    Industrial hydrogenation is often performed using a slurry catalyst in large stirred-tank reactors. These systems are inherently problematic in a number of areas, including industrial hygiene, process safety, environmental contamination, waste production, process operability and productivity. This program proposed the development of a practical replacement for the slurry catalysts using a novel fixed-bed monolith catalyst reactor, which could be retrofitted onto an existing stirred-tank reactor and would mitigate many of the minitations and problems associated with slurry catalysts. The full retrofit monolith system, consisting of a recirculation pump, gas/liquid ejector and monolith catalyst, is described as a monolith loop reactor or MLR. The MLR technology can reduce waste and increase raw material efficiency, which reduces the overall energy required to produce specialty and fine chemicals.

  8. Photoelectrochemical hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Rocheleau, R.E.; Miller, E.; Misra, A. [Univ. of Hawaii, Honolulu, HI (United States)

    1996-10-01

    The large-scale production of hydrogen utilizing energy provided by a renewable source to split water is one of the most ambitious long-term goals of the U.S. Department of Energy`s Hydrogen Program. One promising option to meet this goal is direct photoelectrolysis in which light absorbed by semiconductor-based photoelectrodes produces electrical power internally to split water into hydrogen and oxygen. Under this program, direct solar-to-chemical conversion efficiencies as high as 7.8 % have been demonstrated using low-cost, amorphous-silicon-based photoelectrodes. Detailed loss analysis models indicate that solar-to-chemical conversion greater than 10% can be achieved with amorphous-silicon-based structures optimized for hydrogen production. In this report, the authors describe the continuing progress in the development of thin-film catalytic/protective coatings, results of outdoor testing, and efforts to develop high efficiency, stable prototype systems.

  9. Performance characterization of a hydrogen catalytic heater.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry Alan; Kanouff, Michael P.

    2010-04-01

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

  10. On the role of metal particle size and surface coverage for photo-catalytic hydrogen production; a case study of the Au/CdS system

    KAUST Repository

    Majeed, I.

    2015-09-25

    Photo-catalytic hydrogen production has been studied on Au supported CdS catalysts under visible light irradiation in order to understand the effect of Au particle size as well as the reaction medium properties. Au nanoparticles of size about 2-5 nm were deposited over hexagonal CdS particles using a new simple method involving reduction of Au3+ ions with iodide ions. Within the investigated range of Au (between 1 and 5 wt. %) fresh particles with mean size of 4 nm and XPS Au4f/Cd3d surface ratio of 0.07 showed the highest performance (ca. 1 molecule of H2 / Auatom s−1) under visible light irradiation (>420 nm and a flux of 35 mW/cm2). The highest hydrogen production rate was obtained from water (92%)-ethanol (8%) in an electrolyte medium (Na2S-Na2SO3). TEM studies of fresh and used catalysts showed that Au particle size increases (almost 5 fold) with increasing photo-irradiation time due to photo-agglomeration effect yet no sign of deactivation was observed. A mechanism for hydrogen production from ethanol-water electrolyte mixture is presented and discussed.

  11. Valorization of Waste Lipids through Hydrothermal Catalytic Conversion to Liquid Hydrocarbon Fuels with in Situ Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongwook; Vardon, Derek R.; Murali, Dheeptha; Sharma, Brajendra K.; Strathmann, Timothy J.

    2016-03-07

    We demonstrate hydrothermal (300 degrees C, 10 MPa) catalytic conversion of real waste lipids (e.g., waste vegetable oil, sewer trap grease) to liquid hydrocarbon fuels without net need for external chemical inputs (e.g., H2 gas, methanol). A supported bimetallic catalyst (Pt-Re/C; 5 wt % of each metal) previously shown to catalyze both aqueous phase reforming of glycerol (a triacylglyceride lipid hydrolysis coproduct) to H2 gas and conversion of oleic and stearic acid, model unsaturated and saturated fatty acids, to linear alkanes was applied to process real waste lipid feedstocks in water. For reactions conducted with an initially inert headspace gas (N2), waste vegetable oil (WVO) was fully converted into linear hydrocarbons (C15-C17) and other hydrolyzed byproducts within 4.5 h, and H2 gas production was observed. Addition of H2 to the initial reactor headspace accelerated conversion, but net H2 production was still observed, in agreement with results obtained for aqueous mixtures containing model fatty acids and glycerol. Conversion to liquid hydrocarbons with net H2 production was also observed for a range of other waste lipid feedstocks (animal fat residuals, sewer trap grease, dry distiller's grain oil, coffee oil residual). These findings demonstrate potential for valorization of waste lipids through conversion to hydrocarbons that are more compatible with current petroleum-based liquid fuels than the biodiesel and biogas products of conventional waste lipid processing technologies.

  12. Ultrathin Co(Ni)-doped MoS2 nanosheets as catalytic promoters enabling efficient solar hydrogen production

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Ma; Jinquan Li; Changhua An; Juan Feng; Yuhua Chi; Junxue Liu; Jun Zhang

    2016-01-01

    The design of efficient artificial photosynthetic systems that harvest solar energy to drive the hydrogen evolution reaction via water reduction is of great importance from both the theoretical and practical viewpoints.Integrating appropriate co-catalyst promoters with strong light absorbing materials represents an ideal strategy to enhance the conversion efficiency of solar energy in hydrogen production.Herein,we report,for the first time,the synthesis of a class of unique hybrid structures consisting of ultrathin Co(Ni)-doped MoS2 nanosheets (co-catalyst promoter) intimately grown on semiconductor CdS nanorods (light absorber).The as-synthesized one-dimensional CdS@doped-MoS2 heterostructures exhibited very high photocatalytic activity (with a quantum yield of 17.3%) and stability towards H2 evolution from the photoreduction of water.Theoretical calculations revealed that Ni doping can increase the number of uncoordinated atoms at the edge sites of MoS2 nanosheets to promote electron transfer across the CdS/MoS2 interfaces as well as hydrogen reduction,leading to an efficient H2 evolution reaction.

  13. Immobilization of the [FeFe]-hydrogenase CrHydA1 on a gold electrode: design of a catalytic surface for the production of molecular hydrogen.

    Science.gov (United States)

    Krassen, Henning; Stripp, Sven; von Abendroth, Gregory; Ataka, Kenichi; Happe, Thomas; Heberle, Joachim

    2009-06-01

    Hydrogenase-modified electrodes are a promising catalytic surface for the electrolysis of water with an overpotential close to zero. The [FeFe]-hydrogenase CrHydA1 from the photosynthetic green alga Chlamydomonas reinhardtii is the smallest [FeFe]-hydrogenase known and exhibits an extraordinary high hydrogen evolution activity. For the first time, we immobilized CrHydA1 on a gold surface which was modified by different carboxy-terminated self-assembled monolayers. The immobilization was in situ monitored by surface-enhanced infrared spectroscopy. In the presence of the electron mediator methyl viologen the electron transfer from the electrode to the hydrogenase was detected by cyclic voltammetry. The hydrogen evolution potential (-290 mV vs NHE, pH 6.8) of this protein modified electrode is close to the value for bare platinum (-270 mV vs NHE). The surface coverage by CrHydA1 was determined to 2.25 ng mm(-2) by surface plasmon resonance, which is consistent with the formation of a protein monolayer. Hydrogen evolution was quantified by gas chromatography and the specific hydrogen evolution activity of surface-bound CrHydA1 was calculated to 1.3 micromol H(2)min(-1)mg(-1) (or 85 mol H(2)min(-1)mol(-1)). In conclusion, a viable hydrogen-evolving surface was developed that may be employed in combination with immobilized photosystems to provide a platform for hydrogen production from water and solar energy with enzymes as catalysts. PMID:19480942

  14. Catalytic production of biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Theilgaard Madsen, A.

    2011-07-01

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

  15. Green diesel production via catalytic hydrogenation/decarboxylation of triglycerides and fatty acids of vegetable oil and brown grease

    Science.gov (United States)

    Sari, Elvan

    Increase in the petroleum prices, projected increases in the world's energy demand and environmental awareness have shifted the research interest to the alternative fuel technologies. In particular, green diesel, vegetable oil/animal fat/waste oil and grease derived hydrocarbons in diesel boiling range, has become an attractive alternative to biodiesel---a mixture of fatty acid methyl esters, particularly due to its superior fuel properties that are similar to petroleum diesel. Hence, green diesel can be used as a drop-in fuel in the current diesel engines. The current technology for production of green diesel-hydrodeoxygenation of triglycerides and fatty acids over conventional hydrotreating catalysts suffers from fast catalyst deactivation in the absence of hydrogen combined with high temperatures and high fatty acid content in the feedstock. Additionally, excess hydrogen requirement for hydrodeoxygenation technique leads to high production costs. This thesis proposes a new technology-selective decarboxylation of brown grease, which is a mixture of fats and oils collected from waste water trap and rich in fatty acids, over a supported noble metal catalyst that overcomes the green diesel production challenges. In contrast to other feedstocks used for liquid biofuel production, brown grease is inexpensive and non-food competing feedstock, therefore the process finds solution to waste management issues, reduces the renewable fuel production cost and does not add to the global food shortage problems. Special catalyst formulations were developed to have a high activity and stability in the absence of hydrogen in the fatty acid decarboxylation process. The study shows how catalyst innovations can lead to a new technology that overcomes the process challenges. First, the effect of reaction parameters on the activity and the selectivity of brown grease decarboxylation with minimum hydrogen consumption over an activated carbon supported palladium catalyst were

  16. Simulation Studies of the Hydrogen Production from Methanol Partial Oxidation Steam Reforming by a Tubular Packed-bed Catalytic Reactor*

    Institute of Scientific and Technical Information of China (English)

    蒋元力; 林美淑; 金东显

    2001-01-01

    Hydrogen production by partial oxidation steam reforming of methanol over a Cu/ZnO/Al2O3 cata-lyst has been paid more and more attention. The chemical equilibria involved in the methanol pvxtial oxidation steam reforming reaction network such as methanol partial oxidation, methanol steam reforming, decomposition of methanol and water-gas shift reaction have been examined over the ranges of temperature 473---1073 K under normal pressure. Based on the detailed kinetics of these reactions over a Cu/ZnO/Al2O3 catalyst, and from the basic concept of the effectiveness factor, the intraparticle diffusion limitations were taken into account. The effectiveness factors for each reaction along the bed length were calculated. Then important results were offered for the simulation of this reaction process.

  17. Simulation Studies of the Hydrogen Production from Methanol Partial Oxidation Steam Reforming by a Tubular Packed-bed Catalytic Reactor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Hydrogen production by partial oxidation steam reforming of methanol over a Cu/ZnO/Al2 O3 cata lyst has been paid more and more attention. The chemical equilibria involved in the methanol partial oxidation steam reforming reaction network such as methanol partial oxidation, methanol steam reforming, decomposition of methanol and water-gas shift reaction have been examined over the ranges of temperature 473-1073 K under normal pressure. Based on the detailed kinetics of these reactions over a Cu/ZnO/Al2O3 catalyst, and from the basic concept of the effectiveness factor, the intraparticle diffusion limitations were taken into account. The effec tiveness factors for each reaction along the bed length were calculated. Then important results were offered for the simulation of this reaction process.

  18. Production of bio-hydrogenated diesel by catalytic hydrotreating of palm oil over NiMoS2/γ-Al2O3 catalyst.

    Science.gov (United States)

    Srifa, Atthapon; Faungnawakij, Kajornsak; Itthibenchapong, Vorranutch; Viriya-Empikul, Nawin; Charinpanitkul, Tawatchai; Assabumrungrat, Suttichai

    2014-04-01

    Catalytic hydrotreating of palm oil (refined palm olein type) to produce bio-hydrogenated diesel (BHD) was carried out in a continuous-flow fixed-bed reactor over NiMoS2/γ-Al2O3 catalyst. Effects of dominant hydrotreating parameters: temperature: 270-420°C; H2 pressure: 15-80 bar; LHSV: 0.25-5.0 h(-1); and H2/oil ratio: 250-2000 N(cm(3)/cm(3)) on the conversion, product yield, and a contribution of hydrodeoxygenation (HDO) and decarbonylation/decarboxylation (DCO/DCO2) were investigated to find the optimal hydrotreating conditions. All calculations including product yield and the contribution of HDO and DCO/DCO2 were extremely estimated based on mole balance corresponding to the fatty acid composition in feed to fully understand deoxygenation behaviors at different conditions. These analyses demonstrated that HDO, DCO, and DCO2 reactions competitively occurred at each condition, and had different optimal and limiting conditions. The differences in the hydrotreating reactions, liquid product compositions, and gas product composition were also discussed. PMID:24583218

  19. Study on hydrogen production by catalytic reforming of bio-oil-methanol mixture%生物油-甲醇催化转化制氢

    Institute of Scientific and Technical Information of China (English)

    韩红睿; 张瑞芹; 徐兴敏; 张长森; 刘永刚

    2011-01-01

    Using bio-oil-tnethanol as the raw material, the nickel-based reforming catalyst for hydrogen production prepared in the laboratory was investigated in the fixed micro-reactor. The catalysts before and after reaction were characterized by XRD,BET and SEM. The condensates collected after gasification were analyzed by GC-MS. The results showed that NiCeMg/olivine catalyst exhibited good catalytic activity and good properties of resistance to carbon deposition. The hydrogen yield of 38. 52% and carbon conversion of 68. 29% were attained under the the optimum reaction condition.%以生物油-甲醇为原料,在微型固定反应装置上考察实验室合成镍基催化剂重整制氢的催化效率.对反应前后的催化剂进行XRD、BET和SEM表征分析,并对冷凝液做GC - MS分析.研究发现,实验室自制的NiCeMg/olivine催化剂具有较好的催化活性和一定的抗积炭性能.在选择的最佳反应条件下,氢气产率和碳转化率分别为38.52%和68.29%.

  20. Photoelectrochemical hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Rocheleau, R.E.; Miller, E.; Zhang, Z. [Univ. of Hawaii, Honolulu, HI (United States)

    1995-09-01

    The large-scale production of hydrogen utilizing energy provided by a renewable source to split water is one of the most ambitious long-term goals of the U.S. Department of Energy`s Hydrogen Program. Photoelectrochemical devices-direct photoconversion systems utilizing a photovoltaic-type structure coated with water-splitting catalysts-represent a promising option to meet this goal. Direct solar-to-chemical conversion efficiencies greater than 7% and photoelectrode lifetimes of up to 30 hours in 1 molar KOH have been demonstrated in our laboratory using low-cost, amorphous-silicon-based photoelectrodes. Loss analysis models indicate that the DOE`s goal of 10% solar-to-chemical conversion can be met with amorphous-silicon-based structures optimized for hydrogen production. In this report, we describe recent progress in the development of thin-film catalytic/protective coatings, improvements in photoelectrode efficiency and stability, and designs for higher efficiency and greater stability.

  1. Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach

    Directory of Open Access Journals (Sweden)

    Ateeq Rahman

    2011-01-01

    Full Text Available The catalytic hydrogenation of acetone is an important area of catalytic process to produce fine chemicals. Hydrogenation of acetone has important applications for heat pumps, fuel cells or in fulfilling the sizeable demand for the production of 2-propanol. Catalytic vapour phase hydrogenation of acetone has gained attention over the decades with variety of homogeneous catalysts notably Iridium, Rh, Ru complexes and heterogeneous catalysts comprising of Raney Nickel, Raney Sponge, Ni/Al2O3, Ni/SiO2, or Co-Al2O3, Pd, Rh, Ru, Re, or Fe/Al2O3 supported on SiO2 or MgO and even CoMgAl, NiMg Al layered double hydroxide, Cu metal, CuO, Cu2O. Nano catalysts are developed for actone reduction Ni maleate, cobalt oxide prepared in organic solvents. Author present a review on acetone hydrogenation under different conditions with various homogeneous and heterogeneous catalysts studied so far in literature and new strategies to develop economic and environmentally benign approach. ©2010 BCREC UNDIP. All rights reserved(Received: 16th June 2010, Revised: 18th October 2010; Accepted: 25th October 2010[How to Cite:Ateeq Rahman. (2010. Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach. Bulletin of Chemical Reaction Engineering and Catalysis, 5(2: 113-126. doi:10.9767/bcrec.5.2.798.113-126][DOI: http://dx.doi.org/10.9767/bcrec.5.2.798.113-126 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/798

  2. Skeletal Isomerization and Inter-molecular Hydrogen Transfer Reactions in Catalytic Cracking

    Institute of Scientific and Technical Information of China (English)

    Gao Yongcan; Zhang Jiushun; Xie Chaogang; Long Jun

    2002-01-01

    Bimolecular hydrogen transfer and skeletal isomerization are the important secondary reac tions among catalytic cracking reactions, which affect product yield distribution and product quality.Catalyst properties and operating parameters have great impact on bimolecular hydrogen transfer and skeletal isomerization reactions. Bimolecular hydrogen transfer activity and skeletal isomerization activity of USY-containing catalysts are higher than that of ZSM-5-containing catalyst. Coke deposition on the active sites of catalyst may suppress bimolecular hydrogen transfer activity and skeletal isomerization activity of catalyst in different degrees. Short reaction time causes a decrease of hydrogen trans fer reaction, but an increase of skeletal isomerization reaction compared to cracking reaction in catalytic cracking process.

  3. Catalytic Asymmetric Reduction of a 3,4-Dihydroisoquinoline for the Large-Scale Production of Almorexant: Hydrogenation or Transfer Hydrogenation?

    OpenAIRE

    Verzijl, Gerard K.M.; Vries, André H.M. de; Vries, Johannes G. de; Kapitan, Peter; Dax, Thomas; Helms, Matthias; Nazir, Zarghun; Skranc, Wolfgang; Imboden, Christoph; Stichler, Juergen; Ward, Richard A.; Abele, Stefan; Lefort, Laurent

    2013-01-01

    Several methods are presented for the enantioselective synthesis of the tetrahydroisoquinoline core of almorexant (ACT-078573A), a dual orexin receptor antagonist. Initial clinical supplies were secured by the Noyori Ru-catalyzed asymmetric transfer hydrogenation (Ru-Noyori ATH) of the dihydroisoquinoline precursor. Both the yield and enantioselectivity eroded upon scale-up. A broad screening exercise identified TaniaPhos as ligand for the iridium-catalyzed asymmetric hydrogenation with a ded...

  4. Microchannel Reactor System for Catalytic Hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Adeniyi Lawal; Woo Lee; Ron Besser; Donald Kientzler; Luke Achenie

    2010-12-22

    We successfully demonstrated a novel process intensification concept enabled by the development of microchannel reactors, for energy efficient catalytic hydrogenation reactions at moderate temperature, and pressure, and low solvent levels. We designed, fabricated, evaluated, and optimized a laboratory-scale microchannel reactor system for hydrogenation of onitroanisole and a proprietary BMS molecule. In the second phase of the program, as a prelude to full-scale commercialization, we designed and developed a fully-automated skid-mounted multichannel microreactor pilot plant system for multiphase reactions. The system is capable of processing 1 – 10 kg/h of liquid substrate, and an industrially relevant immiscible liquid-liquid was successfully demonstrated on the system. Our microreactor-based pilot plant is one-of-akind. We anticipate that this process intensification concept, if successfully demonstrated, will provide a paradigm-changing basis for replacing existing energy inefficient, cost ineffective, environmentally detrimental slurry semi-batch reactor-based manufacturing practiced in the pharmaceutical and fine chemicals industries.

  5. Hydrogen production by Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Chaudhuri Surabhi

    2005-12-01

    Full Text Available Abstract The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate. Cyanobacteria are highly promising microorganism for hydrogen production. In comparison to the traditional ways of hydrogen production (chemical, photoelectrical, Cyanobacterial hydrogen production is commercially viable. This review highlights the basic biology of cynobacterial hydrogen production, strains involved, large-scale hydrogen production and its future prospects. While integrating the existing knowledge and technology, much future improvement and progress is to be done before hydrogen is accepted as a commercial primary energy source.

  6. Catalytic Asymmetric Reduction of a 3,4-Dihydroisoquinoline for the Large-Scale Production of Almorexant : Hydrogenation or Transfer Hydrogenation?

    NARCIS (Netherlands)

    Verzijl, Gerard K.M.; Vries, André H.M. de; Vries, Johannes G. de; Kapitan, Peter; Dax, Thomas; Helms, Matthias; Nazir, Zarghun; Skranc, Wolfgang; Imboden, Christoph; Stichler, Juergen; Ward, Richard A.; Abele, Stefan; Lefort, Laurent

    2013-01-01

    Several methods are presented for the enantioselective synthesis of the tetrahydroisoquinoline core of almorexant (ACT-078573A), a dual orexin receptor antagonist. Initial clinical supplies were secured by the Noyori Ru-catalyzed asymmetric transfer hydrogenation (Ru-Noyori ATH) of the dihydroisoqui

  7. Hydrogen production from co-gasification of coal and biomass in supercritical water by continuous flow thermal-catalytic reaction system

    Institute of Scientific and Technical Information of China (English)

    YAN Qiuhui; GUO Liejin; LIANG Xing; ZHANG Ximin

    2007-01-01

    Hydrogen is a clean energy carrier.Converting abundant coal sources and green biomass energy into hydrogen effectively and without any pollution promotes environmental protection.The co-gasification performance of coal and a model compound of biomass,carboxymethylcellulose (CMC)in supercritical water (SCW),were investigated experimentally.The influences of temperature,pressure and concentration on hydrogen production from co-gasification of coal and CMC in SCW under the given conditions (20-25 MPa,650℃,15-30 s) are discussed in detail.The experimental results show that H2,CO2 and CH4 are the main gas products,and the molar fraction of hydrogen reaches in excess of 60%.The higher pressure and higher CMC content facilitate hydrogen production;production is decreased remarkably given a longer residence time.

  8. Photobiological hydrogen production.

    Science.gov (United States)

    Asada, Y; Miyake, J

    1999-01-01

    The principles and recent progress in the research and development of photobiological hydrogen production are reviewed. Cyanobacteria produce hydrogen gas using nitrogenase and/or hydrogenase. Hydrogen production mediated by native hydrogenases in cyanobacteria occurs under in the dark under anaerobic conditions by degradation of intracellular glycogen. In vitro and in vivo coupling of the cyanobacterial photosynthetic system with a clostridial hydrogenase via cyanobacterial ferredoxin was demonstrated in the presence of light. Genetic transformation of Synechococcus PCC7942 with the hydrogenase gene from Clostridium pasteurianum was successful; the active enzyme was expressed in PCC7942. The strong hydrogen producers among photosynthetic bacteria were isolated and characterized. Coculture of Rhodobacter and Clostriudium was applied for hydrogen production from glucose. A mutant strain of Rhodobacter sphaeroides RV whose light-harvesting proteins were altered was obtained by UV irradiation. Hydrogen productivity by the mutant was improved when irradiated with monochromatic light of some wavelengths. The development of photobioreactors for hydrogen production is also reviewed.

  9. Numerical Study of Passive Catalytic Recombiner for Hydrogen Mitigation

    Directory of Open Access Journals (Sweden)

    Pavan K Sharma

    2010-10-01

    Full Text Available A significant amount of hydrogen is expected to be released within the containment of a water cooled power reactor after a severe accident. To reduce the risk of deflagration/detonation various means for hydrogen control have been adopted all over the world. Passive catalytic recombiner with vertical flat catalytic plate is one of such hydrogen mitigating device. Passive catalytic recombiners are designed for the removal of hydrogen generated in order to limit the impact of possible hydrogen combustion. Inside a passive catalytic recombiner, numerous thin steel sheets coated with catalyst material are vertically arranged at the bottom opening of a sheet metal housing forming parallel flow channels for the surrounding gas atmosphere. Already below conventional flammability limits, hydrogen and oxygen react exothermally on the catalytic surfaces forming harmless steam. Detailed numerical simulations and experiments are required for an in-depth knowledge of such plate type catalytic recombiners. Specific finite volume based in-house CFD code has been developed to model and analyse the working of these recombiner. The code has been used to simulate the recombiner device used in the Gx-test series of Battelle-Model Containment (B-MC experiments. The present paper briefly describes the working principle of such passive catalytic recombiner and salient feature of the CFD model developed at Bhabha Atomic Research Centre (BARC. Finally results of the calculations and comparison with existing data are discussed.

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

    International Nuclear Information System (INIS)

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

  11. Co/ZnO and Ni/ZnO catalysts for hydrogen production by bioethanol steam reforming. Influence of ZnO support morphology on the catalytic properties of Co and Ni active phases

    Energy Technology Data Exchange (ETDEWEB)

    Da Costa-Serra, J.F.; Chica, A. [Instituto de Tecnolgia Quimica (UPV-CSIC), Universidad Politecnica de Valencia, Consejo Superior de Investigaciones Cientificas, Avenida de los naranjos s/n, 46022 Valencia (Spain); Guil-Lopez, R. [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid (Spain)

    2010-07-15

    Renewable hydrogen production from steam reforming of bioethanol is an interesting approach to produce sustainable hydrogen. However, simultaneous competitive reactions can occur, decreasing the hydrogen production yield. To overcome this problem, modifications in the steam reforming catalysts are being studied. Ni and Co active phases supported over modified ZnO have been widely studied in hydrogen production from steam reforming of bioethanol. However, the influence of the morphology and particle size of ZnO supports on the catalytic behaviour of the supported Ni and Co has not been reported. In the present work, we show how the morphology, shape, and size of ZnO support particles can control the impregnation process of the metal active centres, which manages the properties of active metallic particles. It has been found that nanorod particles of ZnO, obtained by calcination of Zn acetate, favour the metal-support interactions, decreasing the metallic particle sizes and avoiding metal (Co or Ni) sinterization during the calcination of metal precursors. Small metallic particle sizes lead to high values of active metal exposure surface, increasing the bioethanol conversion and hydrogen production. (author)

  12. Progresses in Catalytic Steam Reforming of Bio-oil for Hydrogen Production%生物油水蒸气催化重整制氢研究进展

    Institute of Scientific and Technical Information of China (English)

    张文涛; 陈明强; 刘少敏; 杨忠连

    2014-01-01

    氢气作为一种环境友好的清洁能源,人们对它的关注度越来越高。生物油水蒸气催化重整制氢是未来制氢的一种可行性方案。本文综述了近年来生物油水蒸气重整制氢的研究进展。主要从重整制氢反应机理、热力学分析、催化重整催化剂、代表性的重整反应器方面进行讨论,指出催化重整中的主要问题是碳沉积导致催化剂失活。研制高活性、高稳定性、高选择性的催化剂是生物油催化重整制氢的关键。%Hydrogen is regarded as an environmentally friendly clean energy and has been paid more and more attention. Catalytic steam reforming of bio-oil is a feasible solution for future hydrogen production. The recent progress of catalytic steam reforming of bio-oil for hydrogen production was reviewed in this paper. Some respects such as reaction mechanism, thermodynamic analysis, catalysts, and typical reactors of catalytic steam reforming of bio-oil were discussed. The deactivation of catalyst caused by carbon deposition is pointed out as the main problem during the reforming process. Therefore, the key factor of catalytic reforming of bio-oil is to develop high activity, high stability, and high selectivity catalysts.

  13. Synthesis and Catalytic Hydrogen Transfer Reaction of Ruthenium(II) Complex

    Energy Technology Data Exchange (ETDEWEB)

    Son, Jung Ik; Kim, Aram; Noh, Hui Bog; Lee, Hyun Ju; Shim, Yoon Bo; Park, Kang Hyun [Pusan National University, Busan (Korea, Republic of)

    2012-01-15

    The ruthenium(II) complex [Ru(bpy){sub 2}-(PhenTPy)] was synthesized, and used for the transfer hydrogenation of ketones and the desired products were obtained in good yield. Based on the presented results, transition-metal complexes can be used as catalysts for a wide range of organic transformations. The relationship between the electro-reduction current density and temperature are being examined in this laboratory. Attempts to improve the catalytic activity and determine the transfer hydrogenation mechanism are currently in progress. The catalytic hydrogenation of a ketone is a basic and critical process for making many types of alcohols used as the final products and precursors in the pharmaceutical, agrochemical, flavor, fragrance, materials, and fine chemicals industries. The catalytic hydrogenation process developed by Noyori is a very attractive process. Formic acid and 2-propanol have been used extensively as hydrogenation sources. The advantage of using 2-propanol as a hydrogen source is that the only side product will be acetone, which can be removed easily during the workup process. Hydrogen transfer (HT) catalysis, which generates alcohols through the reduction of ketones, is an attractive protocol that is used widely. Ruthenium(II) complexes are the most useful catalysts for the hydrogen transfer (HT) of ketones. In this method, a highly active catalytic system employs a transition metal as a catalyst to synthesize alcohols, and is a replacement for the hydrogen-using hydrogenation process. The most active system is based on Ru, Rh and Ir, which includes a nitrogen ligand that facilitates the formation of a catalytically active hydride and phosphorus.

  14. Synthesis and Catalytic Hydrogen Transfer Reaction of Ruthenium(II) Complex

    International Nuclear Information System (INIS)

    The ruthenium(II) complex [Ru(bpy)2-(PhenTPy)] was synthesized, and used for the transfer hydrogenation of ketones and the desired products were obtained in good yield. Based on the presented results, transition-metal complexes can be used as catalysts for a wide range of organic transformations. The relationship between the electro-reduction current density and temperature are being examined in this laboratory. Attempts to improve the catalytic activity and determine the transfer hydrogenation mechanism are currently in progress. The catalytic hydrogenation of a ketone is a basic and critical process for making many types of alcohols used as the final products and precursors in the pharmaceutical, agrochemical, flavor, fragrance, materials, and fine chemicals industries. The catalytic hydrogenation process developed by Noyori is a very attractive process. Formic acid and 2-propanol have been used extensively as hydrogenation sources. The advantage of using 2-propanol as a hydrogen source is that the only side product will be acetone, which can be removed easily during the workup process. Hydrogen transfer (HT) catalysis, which generates alcohols through the reduction of ketones, is an attractive protocol that is used widely. Ruthenium(II) complexes are the most useful catalysts for the hydrogen transfer (HT) of ketones. In this method, a highly active catalytic system employs a transition metal as a catalyst to synthesize alcohols, and is a replacement for the hydrogen-using hydrogenation process. The most active system is based on Ru, Rh and Ir, which includes a nitrogen ligand that facilitates the formation of a catalytically active hydride and phosphorus

  15. Hydrogen production by Cyanobacteria

    OpenAIRE

    Chaudhuri Surabhi; De, Debojyoti; Dutta Debajyoti; Bhattacharya Sanjoy K

    2005-01-01

    Abstract The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate. Cyanobacteria are highly promising microorganism for hydrogen production. In comparison to...

  16. Short hydrogen bonds in the catalytic mechanism of serine proteases

    Directory of Open Access Journals (Sweden)

    VLADIMIR LESKOVAC

    2008-04-01

    Full Text Available The survey of crystallographic data from the Protein Data Bank for 37 structures of trypsin and other serine proteases at a resolution of 0.78–1.28 Å revealed the presence of hydrogen bonds in the active site of the enzymes, which are formed between the catalytic histidine and aspartate residues and are on average 2.7 Å long. This is the typical bond length for normal hydrogen bonds. The geometric properties of the hydrogen bonds in the active site indicate that the H atom is not centered between the heteroatoms of the catalytic histidine and aspartate residues in the active site. Taken together, these findings exclude the possibility that short “low-barrier” hydrogen bonds are formed in the ground state structure of the active sites examined in this work. Some time ago, it was suggested by Cleland that the “low-barrier hydrogen bond” hypothesis is operative in the catalytic mechanism of serine proteases, and requires the presence of short hydrogen bonds around 2.4 Å long in the active site, with the H atom centered between the catalytic heteroatoms. The conclusions drawn from this work do not exclude the validity of the “low-barrier hydrogen bond” hypothesis at all, but they merely do not support it in this particular case, with this particular class of enzymes.

  17. Preparation, structural characterization and catalytic properties of Co/CeO2 catalysts for the steam reforming of ethanol and hydrogen production

    Science.gov (United States)

    Lovón, Adriana S. P.; Lovón-Quintana, Juan J.; Almerindo, Gizelle I.; Valença, Gustavo P.; Bernardi, Maria I. B.; Araújo, Vinícius D.; Rodrigues, Thenner S.; Robles-Dutenhefner, Patrícia A.; Fajardo, Humberto V.

    2012-10-01

    In this paper, Co/CeO2 catalysts, with different cobalt contents were prepared by the polymeric precursor method and were evaluated for the steam reforming of ethanol. The catalysts were characterized by N2 physisorption (BET method), X-ray diffraction (XRD), UV-visible diffuse reflectance, temperature programmed reduction analysis (TPR) and field emission scanning electron microscopy (FEG-SEM). It was observed that the catalytic behavior could be influenced by the experimental conditions and the nature of the catalyst employed. Physical-chemical characterizations revealed that the cobalt content of the catalyst influences the metal-support interaction which results in distinct catalyst performances. The catalyst with the highest cobalt content showed the best performance among the catalysts tested, exhibiting complete ethanol conversion, hydrogen selectivity close to 66% and good stability at a reaction temperature of 600 °C.

  18. Hydrogen production methods

    International Nuclear Information System (INIS)

    Old, present and new proceses for producing hydrogen are assessed critically. The emphasis throughout is placed on those processes which could be commercially viable before the turn of the century for large-scale hydrogen manufacture. Electrolysis of water is the only industrial process not dependent on fossil resources for large-scale hydrogen production and is likely to remain so for the next two or three decades. While many new processes, including those utilizing sunlight directly or indirectly, are presently not considered to be commercially viable for large-scale hydrogen production, research and development effort is needed to enhance our understanding of the nature of these processes. Water vapour electrolysis is compared with thermochemical processes: the former has the potential for displacing all other processes for producing hydrogen and oxygen from water

  19. Biological hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J.R. [Univ. of California, Berkeley, CA (United States)

    1995-11-01

    Biological hydrogen production can be accomplished by either thermochemical (gasification) conversion of woody biomass and agricultural residues or by microbiological processes that yield hydrogen gas from organic wastes or water. Biomass gasification is a well established technology; however, the synthesis gas produced, a mixture of CO and H{sub 2}, requires a shift reaction to convert the CO to H{sub 2}. Microbiological processes can carry out this reaction more efficiently than conventional catalysts, and may be more appropriate for the relatively small-scale of biomass gasification processes. Development of a microbial shift reaction may be a near-term practical application of microbial hydrogen production.

  20. Photoelectrochemical hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Rocheleau, R.; Misra, A.; Miller, E. [Univ. of Hawaii, Honolulu, HI (United States)

    1998-08-01

    A significant component of the US DOE Hydrogen Program is the development of a practical technology for the direct production of hydrogen using a renewable source of energy. High efficiency photoelectrochemical systems to produce hydrogen directly from water using sunlight as the energy source represent one of the technologies identified by DOE to meet this mission. Reactor modeling and experiments conducted at UH provide strong evidence that direct solar-to-hydrogen conversion efficiency greater than 10% can be expected using photoelectrodes fabricated from low-cost, multijunction (MJ) amorphous silicon solar cells. Solar-to-hydrogen conversion efficiencies as high as 7.8% have been achieved using a 10.3% efficient MJ amorphous silicon solar cell. Higher efficiency can be expected with the use of higher efficiency solar cells, further improvement of the thin film oxidation and reduction catalysts, and optimization of the solar cell for hydrogen production rather than electricity production. Hydrogen and oxygen catalysts developed under this project are very stable, exhibiting no measurable degradation in KOH after over 13,000 hours of operation. Additional research is needed to fully optimize the transparent, conducting coatings which will be needed for large area integrated arrays. To date, the best protection has been afforded by wide bandgap amorphous silicon carbide films.

  1. Biomimetic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Krassen, Henning

    2009-05-15

    Hydrogenases catalyze the reduction of protons to molecular hydrogen with outstanding efficiency. An electrode surface which is covered with active hydrogenase molecules becomes a promising alternative to platinum for electrochemical hydrogen production. To immobilize the hydrogenase on the electrode, the gold surface was modified by heterobifunctional molecules. A thiol headgroup on one side allowed the binding to the gold surface and the formation of a self-assembled monolayer. The other side of the molecules provided a surface with a high affinity for the hydrogenase CrHydA1 from Chlamydomonas reinhardtii. With methylviologen as a soluble energy carrier, electrons were transferred from carboxy-terminated electrodes to CrHydA1 and conducted to the active site (H-cluster), where they reduce protons to molecular hydrogen. A combined approach of surface-enhanced infrared absorption spectroscopy, gas chromatography, and surface plasmon resonance allowed quantifying the hydrogen production on a molecular level. Hydrogen was produced with a rate of 85 mol H{sub 2} min{sup -1} mol{sup -1}. On a 1'- benzyl-4,4'-bipyridinum (BBP)-terminated surface, the electrons were mediated by the monolayer and no soluble electron carrier was necessary to achieve a comparable hydrogen production rate (approximately 50% of the former system). The hydrogen evolution potential was determined to be -335 mV for the BBP-bound hydrogenase and -290 mV for the hydrogenase which was immobilized on a carboxy-terminated mercaptopropionic acid SAM. Therefore, both systems significantly reduce the hydrogen production overpotential and allow electrochemical hydrogen production at an energy level which is close to the commercially applied platinum electrodes (hydrogen evolution potential of -270 mV). In order to couple hydrogen production and photosynthesis, photosystem I (PS1) from Synechocystis PCC 6803 and membrane-bound hydrogenase (MBH) from Ralstonia eutropha were bound to each other

  2. Photobiological hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Seibert, M.; Lien, S.; Weaver, P.F.

    1979-01-01

    Hydrogen production by phototrophic organisms, which has been known since the 1930's, occurs at the expense of light energy and electron-donating substrates. Three classes of organisms, namely, photosynthetic bacteria, cyanobacteria, and algae carry out this function. The primary hydrogen-producing enzyme systems, hydrogenase and nitrogenase, will be discussed along with the manner in which they couple to light-driven electron transport. In addition, the feasibility of using in vivo and in vitro photobiological hydrogen producing systems in future solar energy conversion applications will be examined.

  3. Photobiological hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Seibert, M; Lien, S; Weaver, P F

    1979-01-01

    Hydrogen production by phototrophic organisms, which has been known since the 1930's, occurs at the expense of light energy and electron-donating substrates. Three classes of organisms, namely, photosynthetic bacteria, cyanobacteria, and algae carry out this function. The primary hydrogen-producing enzyme systems, hydrogenase and nitrogenase, will be discussed along with the manner in which they couple to light-driven electron transport. In addition, the feasibility of using in vivo and in vitro photobiological hydrogen producing systems in future solar energy conversion applications will be examined.

  4. Review of literature on catalytic recombination of hydrogen--oxygen

    International Nuclear Information System (INIS)

    The results are reported of a literature search for information concerning the heterogeneous, gas phase, catalytic hydrogen-oxygen recombination. Laboratory scale experiments to test the performance of specific metal oxide catalysts under conditions simulating the atmosphere within a nuclear reactor containment vessel following a loss-of-coolant blowdown accident are suggested

  5. Catalytic Hydrogenation Reaction of Naringin-Chalcone. Study of the Electrochemical Reaction

    OpenAIRE

    B. A. López de Mishima; H. T. Mishima; A. N. Giannuzzo; M. A. Nazareno

    2000-01-01

    The electrocatalytic hydrogenation reaction of naringin derivated chalcone is studied. The reaction is carried out with different catalysts in order to compare with the classic catalytic hydrogenation.

  6. Photoelectrochemical Hydrogen Production

    CERN Document Server

    Krol, R van de

    2012-01-01

    Photoelectrochemical Hydrogen Production describes the principles and materials challenges for the conversion of sunlight into hydrogen through water splitting at a semiconducting electrode. Readers will find an analysis of the solid state properties and materials requirements for semiconducting photo-electrodes, a detailed description of the semiconductor/electrolyte interface, in addition to the photo-electrochemical (PEC) cell. Experimental techniques to investigate both materials and PEC device performance are outlined, followed by an overview of the current state-of-the-art in PEC materia

  7. Catalytic hydrogen evolution by polyaminoacids using mercury electrode

    Directory of Open Access Journals (Sweden)

    Marko Živanovič

    2010-12-01

    Full Text Available It was shown that using constant current chronopotentiometricstripping (CPS peptides and proteins at nanomolar concentrations produce protein structure–sensitive peak H at mercury electrodes. This peak is due to the catalytic hydrogen evolution reaction (HER. Polyamino acids can be considered as an intermediate model system between peptides and macromolecular proteins. Here we used polyamino acids (poly(aa such as polylysine (polyLys and polyarginine (polyArg and cyclic voltammetry or CPS in combination with hanging mercury drop electrode to explore how different amino acid residues in proteins contribute to the catalyticHER.

  8. Preparation of Hydrogen through Catalytic Steam Reforming of Bio-oil

    Institute of Scientific and Technical Information of China (English)

    吴层; 颜涌捷; 李庭琛; 亓伟

    2007-01-01

    Hydrogen was prepared via catalytic steam reforming of bio-oil which was obtained from fast pyrolysis of biomass in a fluidized bed reactor. Influential factors including temperature, weight hourly space velocity (WHSV) of bio-oil, mass ratio of steam to bio-oil (S/B) as well as catalyst type on hydrogen selectivity and other desirable gas products were investigated. Based on hydrogen in stoichiometric potential and carbon balance in gaseous phase and feed, hydrogen yield and carbon selectivity were examined. The experimental results show that higher temperature favors the hydrogen selectivity by H2 mole fraction in gaseous products stream and it plays an important role in hydrogen yield and carbon selectivity. Higher hydrogen selectivity and yield, and carbon selectivity were obtained at lower bio-oil WHSV. In catalytic steam reforming system a maximum steam concentration value exists, at which hydrogen selectivity and yield, and carbon selectivity keep constant. Through experiments, preferential operation conditions were obtained as follows: temperature 800~850℃, bio-oil WHSV below 3.0 h-1, and mass ratio of steam to bio-oil 10~12. The performance tests indicate that Ni-based catalysts are optional, especially Ni/a-Al2O3 effective in the steam reforming process.

  9. Hydrogen production unit

    Energy Technology Data Exchange (ETDEWEB)

    Podgornyy, A.N.; Droshenkin, B.A.; Khmelnitskaya, I.A.; Varshavskiy, I.L.

    1981-01-01

    The unit for hydrogen production consists of a reactor, tank for fuel, tank for water, connected to the injector, and motor. It is distinguished by the fact that in order to reduce energy outlays by purifying the hydrogen and separating it from the gas mixture, it is equipped with a hydrogen separator arranged between the reactor and the motor. The separator is made in the form of a cylindrical shell separated by semipermeable partition into a chamber for pure hydrogen connected to the motor, and a chamber of ballast gas whose outlet is connected to the pressure nozzle of the injector. The use of the semipermeable partition for water vapor and permeable for hydrogen in combination with the injector makes it possible to exclude from the equipment a water pump and outlets of electricity associated with it. In addition, it is not necessary to install a current generator to power the electric motor of this pump. The heat exchanger for heating the water is also excluded.

  10. Photovoltaic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Hiser, H.W.; Memory, S.B.; Veziroglu, T.N.; Padin, J. [Univ. of Miami, Coral Gables, FL (United States)

    1996-10-01

    This is a new project, which started in June 1995, and involves photovoltaic hydrogen production as a fuel production method for the future. In order to increase the hydrogen yield, it was decided to use hybrid solar collectors to generate D.C. electricity, as well as high temperature steam for input to the electrolyzer. In this way, some of the energy needed to dissociate the water is supplied in the form of heat (or low grade energy), to generate steam, which results in a reduction of electrical energy (or high grade energy) needed. As a result, solar to hydrogen conversion efficiency is increased. In the above stated system, the collector location, the collector tracking sub-system (i.e., orientation/rotation), and the steam temperature have been taken as variables. Five locations selected - in order to consider a variety of latitudes, altitudes, cloud coverage and atmospheric conditions - are Atlanta, Denver, Miami, Phoenix and Salt Lake City. Plain PV and hybrid solar collectors for a stationary south facing system and five different collector rotation systems have been analyzed. Steam temperatures have been varied between 200{degrees}C and 1200{degrees}C. During the first year, solar to hydrogen conversion efficiencies have been considered. The results show that higher steam temperatures, 2 dimensional tracking system, higher elevations and dryer climates causes higher conversion efficiencies. Cost effectiveness of the sub-systems and of the overall system will be analyzed during the second year. Also, initial studies will be made of an advanced high efficiency hybrid solar hydrogen production system.

  11. Design, construction and implementation of a packed reactor system to study the production of hydrogen by the catalytic reaction of reforming of oxygenated hydrocarbons

    International Nuclear Information System (INIS)

    The Laboratorio de Quimica Inorganica of the Universidad de Costa Rica has evaluated the performance of several types of catalysts and supports in steam reforming reactions, using different conditions for synthesis of the same. The construction of a reaction system at laboratory scale is described to improve the conditions of the reforming process compared to previous projects. Catalysts synthesized and characterized are used but providing better disposal through a packed bed reactor. The system has had the necessary instrumentation for proper measurement of the temperature at the entrance and inside the reactor, proper feeding of reactants, flow measurement and sampling and measurement system. The conceptual design of the reactions system presented has taken into account the income of reactants through a peristaltic pump, preheating or vaporization of reagents, income and measurement of carrier gas sampling, take of sampling, flow measurement product, reactor packed and cooler product. The order of each stage is defined and positioning in the entire system. The design of a preheater and a tubular reactor is detailed, taking into account the dimensions and construction materials of each of the pieces. The design is presented in a series of diagrams and then the result of the construction is illustrated by photographs, all work done also has been described. The implementation of the system has described by the coupling of all parties and the respective tests. A basic experimental plan is presented to evaluate the performance of the reaction system, using glycerin as a reactant, demonstrating ability to react and take effective data. Four experiments are performed: vacuum reactor, packed reactor with two types of filling and reactor with an exposed surface cobalt oxide (II) reduced, the gases produced in the reaction are analyzed by gas chromatography. The results are discussed and analyzed, focusing on the overall selectivity of hydrogen relative to methane, and the

  12. Biomimetic Production of Hydrogen

    Science.gov (United States)

    Gust, Devens

    2004-03-01

    The basic reaction for hydrogen generation is formation of molecular hydrogen from two electrons and two protons. Although there are many possible sources for the protons and electrons, and a variety of mechanisms for providing the requisite energy for hydrogen synthesis, the most abundant and readily available source of protons and electrons is water, and the most attractive source of energy for powering the process is sunlight. Not surprisingly, living systems have evolved to take advantage of these sources for materials and energy. Thus, biology provides paradigms for carrying out the reactions necessary for hydrogen production. Photosynthesis in green plants uses sunlight as the source of energy for the oxidation of water to give molecular oxygen, protons, and reduction potential. Some photosynthetic organisms are capable of using this reduction potential, in the form of the reduced redox protein ferredoxin, to reduce protons and produce molecular hydrogen via the action of an hydrogenase enzyme. A variety of other organisms metabolize the reduced carbon compounds that are ultimately the major products of photosynthesis to produce molecular hydrogen. These facts suggest that it might be possible to use light energy to make molecular hydrogen via biomimetic constructs that employ principles similar to those used by natural organisms, or perhaps with hybrid "bionic" systems that combine biomimetic materials with natural enzymes. It is now possible to construct artificial photosynthetic systems that mimic some of the major steps in the natural process.(1) Artificial antennas based on porphyrins, carotenoids and other chromophores absorb light at various wavelengths in the solar spectrum and transfer the harvested excitation energy to artificial photosynthetic reaction centers.(2) In these centers, photoinduced electron transfer uses the energy from light to move an electron from a donor to an acceptor moiety, generating a high-energy charge-separated state

  13. Catalytic Combustion for Ultra-Low NOx Hydrogen Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Etemad, Shahrokh; Baird, Benjamin; Alavandi, Sandeep

    2011-06-30

    Precision Combustion, Inc., (PCI) in close collaboration with Solar Turbines, Incorporated, has developed and demonstrated a combustion system for hydrogen fueled turbines that reduces NOx to low single digit level while maintaining or improving current levels of efficiency and eliminating emissions of carbon dioxide. Full scale Rich Catalytic Hydrogen (RCH1) injector was developed and successfully tested at Solar Turbines, Incorporated high pressure test facility demonstrating low single digit NOx emissions for hydrogen fuel in the range of 2200F-2750F. This development work was based on initial subscale development for faster turnaround and reduced cost. Subscale testing provided promising results for 42% and 52% H2 with NOx emissions of less than 2 ppm with improved flame stability. In addition, catalytic reactor element testing for substrate oxidation, thermal cyclic injector testing to simulate start-stop operation in a gas turbine environment, and steady state 15 atm. operation testing were performed successfully. The testing demonstrated stable and robust catalytic element component life for gas turbine conditions. The benefit of the catalytic hydrogen combustor technology includes capability of delivering near-zero NOx without costly post-combustion controls and without requirement for added sulfur control. In addition, reduced acoustics increase gas turbine component life. These advantages advances Department of Energy (DOE’s) objectives for achievement of low single digit NOx emissions, improvement in efficiency vs. postcombustion controls, fuel flexibility, a significant net reduction in Integrated Gasification Combined Cycle (IGCC) system net capital and operating costs, and a route to commercialization across the power generation field from micro turbines to industrial and utility turbines.

  14. Characteristics of La-modified Ni-Al2O3 and Ni-SiO2 catalysts for COx-free hydrogen production by catalytic decomposition of methane

    Institute of Scientific and Technical Information of China (English)

    Chatla; Anjaneyulu; Velisoju; Vijay; Kumar; Suresh; K.Bhargava; Akula; Venugopal

    2013-01-01

    Hydrotalcite precursors of La modified Ni-Al2O3 and Ni-SiO2 catalysts prepared by co-precipitation method and the catalytic activities were examined for the production of COx-free H2 by CH4 decomposition. Physico-chemical characteristics of fresh, reduced and used catalysts were evaluated by XRD, TPR and O2 pulse chemisorptions, TEM and BET-SA techniques. XRD studies showed phases due to hydrotalcite-like precursors in oven dried form produced dispersed NiO species upon calcination in static air above 450 C. Raman spectra of deactivated samples revealed the presence of both ordered and disordered forms of carbon. Ni-La-Al2O3catalyst with a mole ratio of Ni : La : Al = 2 : 0.1 : 0.9 exhibited tremendously high longevity with a hydrogen production rate of 1300 molH2 mol 1 Ni. A direct relationship between Ni metal surface area and hydrogen yields was established.

  15. Catalytic hydrogenation reactors for the fine chemicals industries. Their design and operation.

    OpenAIRE

    Westerterp, K.R.; Molga, E.J.; Gelder, van, M.

    1997-01-01

    The design and operation of reactors for catalytic, hydrogenation in the fine chemical industries are discussed. The requirements for a good multiproduct catalytic hydrogenation unit as well as the choice of the reactor type are considered. Packed bed bubble column reactors operated without hydrogen recycle are recommended as the best choice to obtain a flexible reactor with good selectivities. The results of an experimental study of the catalytic hydrogenation of 2,4-dinitrotoluene in a mini...

  16. Catalytic production of conjugated fatty acids and oils.

    Science.gov (United States)

    Philippaerts, An; Goossens, Steven; Jacobs, Pierre A; Sels, Bert F

    2011-06-20

    The reactive double bonds in conjugated vegetable oils are of high interest in industry. Traditionally, conjugated vegetable oils are added to paints, varnishes, and inks to improve their drying properties, while recently there is an increased interest in their use in the production of bioplastics. Besides the industrial applications, also food manufactures are interested in conjugated vegetable oils due to their various positive health effects. While the isomer type is less important for their industrial purposes, the beneficial health effects are mainly associated with the c9,t11, t10,c12 and t9,t11 CLA isomers. The production of CLA-enriched oils as additives in functional foods thus requires a high CLA isomer selectivity. Currently, CLAs are produced by conjugation of oils high in linoleic acid, for example soybean and safflower oil, using homogeneous bases. Although high CLA productivities and very high isomer selectivities are obtained, this process faces many ecological drawbacks. Moreover, CLA-enriched oils can not be produced directly with the homogeneous bases. Literature reports describe many catalytic processes to conjugate linoleic acid, linoleic acid methyl ester, and vegetable oils rich in linoleic acid: biocatalysts, for example enzymes and cells; metal catalysts, for example homogeneous metal complexes and heterogeneous catalysts; and photocatalysts. This Review discusses state-of-the-art catalytic processes in comparison with some new catalytic production routes. For each category of catalytic process, the CLA productivities and the CLA isomer selectivity are compared. Heterogeneous catalysis seems the most attractive approach for CLA production due to its easy recovery process, provided that the competing hydrogenation reaction is limited and the CLA production rate competes with the current homogeneous base catalysis. The most important criteria to obtain high CLA productivity and isomer selectivity are (1) absence of a hydrogen donor, (2

  17. Hydrogen production processes

    International Nuclear Information System (INIS)

    The goals of this first Gedepeon workshop on hydrogen production processes are: to stimulate the information exchange about research programs and research advances in the domain of hydrogen production processes, to indicate the domains of interest of these processes and the potentialities linked with the coupling of a nuclear reactor, to establish the actions of common interest for the CEA, the CNRS, and eventually EDF, that can be funded in the framework of the Gedepeon research group. This document gathers the slides of the 17 presentations given at this workshop and dealing with: the H2 question and the international research programs (Lucchese P.); the CEA's research program (Lucchese P., Anzieu P.); processes based on the iodine/sulfur cycle: efficiency of a facility - flow-sheets, efficiencies, hard points (Borgard J.M.), R and D about the I/S cycle: Bunsen reaction (Colette S.), R and D about the I/S cycle: the HI/I2/H2O system (Doizi D.), demonstration loop/chemical engineering (Duhamet J.), materials and corrosion (Terlain A.); other processes under study: the Westinghouse cycle (Eysseric C.), other processes under study at the CEA (UT3, plasma,...) (Lemort F.), database about thermochemical cycles (Abanades S.), Zn/ZnO cycle (Broust F.), H2 production by cracking, high temperature reforming with carbon trapping (Flamant G.), membrane technology (De Lamare J.); high-temperature electrolysis: SOFC used as electrolyzers (Grastien R.); generic aspects linked with hydrogen production: technical-economical evaluation of processes (Werkoff F.), thermodynamic tools (Neveu P.), the reactor-process coupling (Aujollet P.). (J.S.)

  18. A bimodal catalytic membrane having a hydrogen-permselective silica layer on a bimodal catalytic support: Preparation and application to the steam reforming of methane

    OpenAIRE

    Tsuru, Toshinori; Shintani, Hiroaki; Yoshioka, Tomohisa; Asaeda, Masashi

    2006-01-01

    The steam reforming of methane for hydrogen production was experimentally investigated using catalytic membrane reactors, consisting of a microporous silica top layer, for the selective permeation of hydrogen, and an α-alumina support layer, for catalytic reaction of the steam reforming of methane. An α-alumina support layer with a bimodal structure, which was proposed for the enhanced dispersion of Ni catalysts, was prepared by impregnating γ-Al2O3 inside α-Al2O3 microfiltration membranes (1...

  19. Catalytic hydrogen peroxide decomposition on La1-xSrxCo03-d perovskite oxides

    NARCIS (Netherlands)

    Dam, Van-Ahn. T.; Olthuis, W.; Bergveld, P.; Berg, van den A.

    2005-01-01

    Lanthanide perovskite oxides are mentioned as material for hydrogen peroxide sensor because they can catalytically decompose hydrogen peroxide in an aqueous medium. The catalytic properties of these perovskite oxides to hydrogen peroxide are suggested due to their oxygen vacancies influenced by the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-14

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

  1. Catalytic hydrogenation of uranyl nitrate - engineering scale studies

    International Nuclear Information System (INIS)

    Uranous nitrate is employed as partitioning agent for the separation of plutonium from uranium in PUREX process, the conventional process for the reprocessing of spent nuclear fuel. It is currently produced from uranyl nitrate solution by the electrochemical route. Since the conversion is only 50%, an innovative method based on catalytic hydrogenation has been developed. Parametric studies have been carried out on 5 L scale using natural uranyl nitrate solution as fed. Based on these studies, number of runs were carried out on engineering scale using contaminated uranyl nitrate solution. More than 100 kg of uranous nitrate has been made. Performance of the reduction process is described in detail. (author)

  2. Catalytic Response and Stability of Nickel/Alumina for the Hydrogenation of 5-Hydroxymethylfurfural in Water.

    Science.gov (United States)

    Perret, Noémie; Grigoropoulos, Alexios; Zanella, Marco; Manning, Troy D; Claridge, John B; Rosseinsky, Matthew J

    2016-03-01

    The catalytic response of Ni on Al2O3 obtained from Ni-Al layered double hydroxides was studied for the liquid-phase hydrogenation of hydroxymethyl furfural to tetrahydrofuran-2,5-diyldimethanol (THFDM) in water. The successive calcination and reduction of the precursors caused the removal of interlayer hydroxyl and carbonate groups and the reduction of Ni(2+) to Ni(0). Four reduced mixed oxide catalysts were obtained, consisting of different amount of Ni metal contents (47-68 wt%) on an Al-rich amorphous component. The catalytic activity was linked to Ni content whereas selectivity was mainly affected by reaction temperature. THFDM was formed in a stepwise manner at low temperature (353 K) whereas 3-hydroxymethyl cyclopentanone was generated at higher temperature. Coke formation caused deactivation; however, the catalytic activity can be regenerated using heat treatment. The results establish Ni on Al2O3 as a promising catalyst for the production of THFDM in water. PMID:26870940

  3. A Au/Cu2O-TiO2 system for photo-catalytic hydrogen production. A pn-junction effect or a simple case of in situ reduction?

    KAUST Repository

    Sinatra, Lutfan

    2015-02-01

    Photo-catalytic H2 production from water has been studied over Au-Cu2O nanoparticle deposited on TiO2 (anatase) in order to probe into both the plasmon resonance effect (Au nanoparticles) and the pn-junction at the Cu2O-TiO2 interface. The Au-Cu2O composite is in the form of ∼10 nm Au nanoparticles grown on ∼475 nm Cu2O octahedral nanocrystals with (111) facets by partial galvanic replacement. X-ray Photoelectron Spectroscopy (XPS) Cu2p and Auger L3M4,5M4,5 lines indicate that the surface of Cu2O is mainly composed of Cu+. The rate for H2 production (from 95 water/5 ethylene glycol; vol.%) over 2 wt.% (Au/Cu2O)-TiO2 is found to be ∼10 times faster than that on 2 wt.% Au-TiO2 alone. Raman spectroscopy before and after reaction showed the disappearance of Cu+ lines (2Eu) at 220 cm-1. These observations coupled with the induction time observed for the reaction rate suggest that in situ reduction from Cu+ to Cu0 occurs upon photo-excitation. The reduction requires the presence of TiO2 (electron transfer). The prolonged activity of the reaction (with no signs of deactivation) despite the reduction to Cu0 indicates that the latter takes part in the reaction by providing additional sites for the reaction, most likely as recombination centers for hydrogen atoms to form molecular hydrogen. This phenomenon provides an additional route for enhancing the efficiency and lifetime of Cu2O-TiO2 photocatalytic systems, beyond the usually ascribed pn-junction effect.

  4. CATALYTIC HYDROGENATION OF ACRYLATE ASMMETRIC Dd(Ⅱ)—CHELATING RESINS CONTAINING AMINO ACID LIGANDS

    Institute of Scientific and Technical Information of China (English)

    Wangying; WangHongzuo; 等

    1995-01-01

    The catalytic hydrogenation of palladium chelating resins containing chiral amino acid ligands based on lower crosslinked poly(chloroethyl acrylate) and some effects on the rate of hydrogenation were studied.

  5. Catalytic Hydrogenation Reaction of Naringin-Chalcone. Study of the Electrochemical Reaction

    Directory of Open Access Journals (Sweden)

    B. A. López de Mishima

    2000-03-01

    Full Text Available The electrocatalytic hydrogenation reaction of naringin derivated chalcone is studied. The reaction is carried out with different catalysts in order to compare with the classic catalytic hydrogenation.

  6. Microstructured reactors for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Aartun, Ingrid

    2005-07-01

    Small scale hydrogen production by partial oxidation (POX) and oxidative steam reforming (OSR) have been studied over Rh-impregnated microchannel Fecralloy reactors and alumina foams. Trying to establish whether metallic microchannel reactors have special advantages for hydrogen production via catalytic POX or OSR with respect to activity, selectivity and stability was of special interest. The microchannel Fecralloy reactors were oxidised at 1000 deg C to form a {alpha}-Al2O3 layer in the channels in order to enhance the surface area prior to impregnation. Kr-BET measurements showed that the specific surface area after oxidation was approximately 10 times higher than the calculated geometric surface area. Approximately 1 mg Rh was deposited in the channels by impregnation with an aqueous solution of RhCl3. Annular pieces (15 mm o.d.,4 mm i.d., 14 mm length) of extruded {alpha}-Al2O3 foams were impregnated with aqueous solutions of Rh(NO3)3 to obtain 0.01, 0.05 and 0.1 wt.% loadings, as predicted by solution uptake. ICP-AES analyses showed that the actual Rh loadings probably were higher, 0.025, 0.077 and 0.169 wt.% respectively. One of the microchannel Fecralloy reactors and all Al2O3 foams were equipped with a channel to allow for temperature measurement inside the catalytic system. Temperature profiles obtained along the reactor axes show that the metallic microchannel reactor is able to minimize temperature gradients as compared to the alumina foams. At sufficiently high furnace temperature, the gas phase in front of the Rh/Al2O3/Frecralloy microchannel reactor and the 0.025 wt.% Rh/Al2O3 foams ignites. Gas phase ignition leads to lower syngas selectivity and higher selectivity to total oxidation products and hydrocarbon by-products. Before ignition of the gas phase the hydrogen selectivity is increased in OSR as compared to POX, the main contribution being the water-gas shift reaction. After gas phase ignition, increased formation of hydrocarbon by-products

  7. Liquid-Phase Catalytic Hydrogenation of Furfural in Variable Solvent Media

    Institute of Scientific and Technical Information of China (English)

    夏淑倩; 李阳; 商巧燕; 张成武; 马沛生

    2016-01-01

    Water is the most abundant compound inherently existing in bio-oils. Thus understanding the role of water within bio-oils upgrading process is essential for future engineering scale-up design. In this study, furfural was chosen as bio-oils model compound, and the catalytic hydrogenation of furfural over commercial 5%, Ru/C catalyst was firstly investigated in a series of gradient variable water/ethanol mixture solvents. Water had a signifi-cant effect on the distribution of product yields. The dominant reaction pathways varied with the water contents in the water/ethanol mixture solvents. Typically, when ethanol was used as the solvent, the main products were ob-tained by the hydrogenation of carbonyl group or furan ring. When pure water was used as the solvent, the rear-rangement reaction of furfural to cyclopentanone should be selectively promoted theoretically. However, serious polymerization and resinification were observed herein in catalytic hydrogenation system of pure water. The cata-lyst surface was modified by the water-insoluble polymers, and consequently, a relative low yield of cyclopenta-none was obtained. A plausible multiple competitive reaction mechanism between polymerization reaction and the hydrogenation of furfural was suggested in this study. Characterizations(TG,FT-IR,SEM)were employed to analyze and explain our experiments.

  8. Crystal structure of HIV-1 protease in situ product complex and observation of a low-barrier hydrogen bond between catalytic aspartates

    OpenAIRE

    Das, Amit; Prashar, Vishal; Mahale, Smita; Serre, L; Ferrer, J.-L.; Hosur, M. V.

    2006-01-01

    HIV-1 protease is an effective target for designing drugs against AIDS, and structural information about the true transition state and the correct mechanism can provide important inputs. We present here the three-dimensional structure of a bi-product complex between HIV-1 protease and the two cleavage product peptides AETF and YVDGAA. The structure, refined against synchrotron data to 1.65 Å resolution, shows the occurrence of the cleavage reaction in the crystal, with the product peptides st...

  9. High Selective Determination of Anionic Surfactant Using Its Parallel Catalytic Hydrogen Wave

    Institute of Scientific and Technical Information of China (English)

    过玮; 何盈盈; 宋俊峰

    2003-01-01

    A faradaic response of anionic surfactants (AS), such as linear aikylbenzene sulfonate (LAS), dodecyl benzene sulfonate and dodecyl sulfate, was observed in weak acidic medium. The faradaic response of AS includes (1) a catalytic hydrogen wave of AS in HAc/NaAc buffer that was attributed to the reduction of proton associated with the sulfo-group of AS, and (2) a parallel catalytic hydrogen wave of AS in the presence of hydrogen peroxide, which was due to the catalysis of the catalytic hydrogen wave of AS by hydroxyl radical OH electrogenerated in the reduction of hydrogen peroxide. The parallel catalytic hydrogen wave is about 50 times as sensitive as the catalytic hydrogen wave. Based on the parallel catalytic hydrogen wave, a high selective method for the determination of AS was developed. In 0.1mol/L HAc/NaAc (pH=6.2±0.1)/1.0×10-3mol/L H2O2 supporting electrolyte, the second-order derivative peak current of the parallel catalytic hydrogen wave located at-1.33 V (vs. SCE) was rectilinear to AS concentration in the range of 3.0×10-6-2.5×10-4mol/L, without the interference of other surfactants. The proposed method was evaluated by quantitative analysis of AS in environmental wastewater.

  10. Modelling of the aerosol deposition in a hydrogen catalytic recombiner

    Energy Technology Data Exchange (ETDEWEB)

    Vendel, J.; Studer, E.; Zavaleta, P. [Inst. de Protection et de Surete Nucleaire, Dept. de Prevention et d' Etudes des Accidents, Gif-sur-Yvette Cedex (France); Hadida, Ph. [Quasar Informatique, Paris (France)

    1997-03-01

    Catalytic recombiners are used to remove the hydrogen released in case of a severe accident in a nuclear power plant, so as to reduce the risk of deflagration or detonation. H{sub 2}PAR experiments are carried out to precise the behaviour of recombiners in term of poisoning by aerosols. Firstly, some calculations have been done with the Trio-EF code to assess the structure of convection loops in the experimental tent. We note that when the recombiner is active, it may have a strong influence on the flow inside the tent and may even interact with an other heat source such as a furnace. In the second part, we study the deposition of aerosols on catalytic plates for a given recombiner, when it is active or passive. We list the different mechanisms and quantify them by introducing the deposition velocity. In fact, thermophoresis appears to be the main mechanism, compared to brownian diffusion or difrusiophoresis, which governs aerosols deposition. It favours deposition on <> plates and acts against it for <> plates. (author)

  11. Hydrogen production processes from biomass

    OpenAIRE

    Shah, Sanjay

    2015-01-01

    Global warming, climate change and energy security have been gaining more attention worldwide. Hydrogen production from biomass offers an effective solution leaving minimal environmental footprint. This thesis identifies and reviews the most potential bio-hydrogen production pathways, identifies and designs the most promising process, and then conducts a rough feasibility study to check its economic potential for commercial production after simulation (experimental part). Finally, it also tes...

  12. Hydrogen production using plasma processing

    International Nuclear Information System (INIS)

    Plasma processing is a promising method of extracting hydrogen from natural gas while avoiding the greenhouse gas (GHG) production typical of other methods such as steam methane reforming. This presentation describes a plasma discharge process based that, in a single reactor pass, can yield hydrogen concentrations of up to 50 % by volume in the product gas mixture. The process is free of GHG's, does not require catalysts and is easily scalable. Chemical and morphological analyses of the gaseous and solid products of the process by gas-chromatography/mass-spectrometry, microscopic Raman analyses and electron microscopy respectively are reviewed. The direct production of hydrogen-enriched natural gas (HENG) as a fuel for low pollution internal combustion engines and its purification to high-purity hydrogen (99.99%) from the product gas by pressure swing adsorption (PSA) purifier beds are reviewed. The presentation reviews potential commercial applications for the technology

  13. Hydrogen Production by Thermophilic Fermentation

    NARCIS (Netherlands)

    Niel, van E.W.J.; Willquist, K.; Zeidan, A.A.; Vrije, de T.; Mars, A.E.; Claassen, P.A.M.

    2012-01-01

    Of the many ways hydrogen can be produced, this chapter focuses on biological hydrogen production by thermophilic bacteria and archaea in dark fermentations. The thermophiles are held as promising candidates for a cost-effective fermentation process, because of their relatively high yields and broad

  14. Experimental studies on catalytic hydrogen recombiners for light water reactors

    International Nuclear Information System (INIS)

    In the course of core melt accidents in nuclear power plants a large amount of hydrogen can be produced and form an explosive or even detonative gas mixture with aerial oxygen in the reactor building. In the containment atmosphere of pressurized water reactors hydrogen combines a phlogistically with the oxygen present to form water vapor even at room temperature. In the past, experimental work conducted at various facilities has contributed little or nothing to an understanding of the operating principles of catalytic recombiners. Hence, the purpose of the present study was to conduct detailed investigations on a section of a recombiner essentially in order to deepen the understanding of reaction kinetics and heat transport processes. The results of the experiments presented in this dissertation form a large data base of measurements which provides an insight into the processes taking place in recombiners. The reaction-kinetic interpretation of the measured data confirms and deepens the diffusion theory - proposed in an earlier study. Thus it is now possible to validate detailed numeric models representing the processes in recombiners. Consequently the present study serves to broaden and corroborate competence in this significant area of reactor technology. In addition, the empirical knowledge thus gained may be used for a critical reassessment of previous numeric model calculations. (orig.)

  15. Catalytic Hydrogenation of Bio-Oil for Chemicals and Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Douglas C.

    2006-02-14

    The scope of work includes optimizing processing conditions and demonstrating catalyst lifetime for catalyst formulations that are readily scaleable to commercial operations. We use a bench-scale, continuous-flow, packed-bed, catalytic, tubular reactor, which can be operated in the range of 100-400 mL/hr., from 50-400 C and up to 20MPa (see Figure 1). With this unit we produce upgraded bio-oil from whole bio-oil or useful bio-oil fractions, specifically pyrolytic lignin. The product oils are fractionated, for example by distillation, for recovery of chemical product streams. Other products from our tests have been used in further testing in petroleum refining technology at UOP and fractionation for product recovery in our own lab. Further scale-up of the technology is envisioned and we will carry out or support process design efforts with industrial partners, such as UOP.

  16. Recent advances in catalytic asymmetric hydrogenation:Renaissance of the monodentate phosphorus ligands

    Institute of Scientific and Technical Information of China (English)

    GUO Hongchao; DING Kuiling; DAI Lixin

    2004-01-01

    The history for the development of chiral phosphorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent advances in the synthesis of the monodentate phosphorus ligands and their applications in catalytic asymmetric hydrogenation. The examples highlighted in this article clearly demonstrated the importance and advantages of monodentate phosphorus ligands, which had been ignored for 30 a and experienced a renaissance at the very beginning of this millennium, particularly in the area of asymmetric hydrogenation.

  17. Electrolytic hydrogen production

    Science.gov (United States)

    Ramani, M. P. S.

    In the role of a secondary energy carrier complementary to electricity in a postfossil-fuel era, hydrogen produced by the elecrolytic splitting of water may be obtained by a variety of methods whose technology development status is presently assessed. Nuclear heat can be converted into hydrogen either directly, via thermal splitting of water, or by means of water electrolysis, which can be of the unipolar tank type or the bipolar filter-press type. An evaluation is made of advanced electrolytic techniques involving exotic materials, as well as solid polymer electrolyte electrolysis and high-temperature water-vapor electrolysis.

  18. Size-Dependent Catalytic Activity of Palladium Nanoparticles Fabricated in Porous Organic Polymers for Alkene Hydrogenation at Room Temperature.

    Science.gov (United States)

    Mondal, John; Trinh, Quang Thang; Jana, Avijit; Ng, Wilson Kwok Hung; Borah, Parijat; Hirao, Hajime; Zhao, Yanli

    2016-06-22

    Ultrafine palladium nanoparticles (Pd NPs) with 8 and 3 nm sizes were effectively fabricated in triazine functionalized porous organic polymer (POP) TRIA that was developed by nonaqueous polymerization of 2,4,6-triallyoxy-1,3,5-triazine. The Pd NPs encapsulated POP (Pd-POP) was fully characterized using several techniques. Further studies revealed an excellent capability of Pd-POP for catalytic transfer hydrogenation of alkenes at room temperature with superior catalytic performance and high selectivity of desired products. Highly flammable H2 gas balloon at high pressure and temperature used in conventional hydrogenation reactions was not needed in the present synthetic system. Catalytic activity is strongly dependent on the size of encapsulated Pd NPs in the POP. The Pd-POP catalyst with Pd NPs of 8 nm in diameter exhibited higher catalytic activity for alkene hydrogenation as compared with the Pd-POP catalyst encapsulating 3 nm Pd NPs. Computational studies were undertaken to gain insights into different catalytic activities of these two Pd-POP catalysts. High reusability and stability as well as no Pd leaching of these Pd-POP catalysts make them highly applicable for hydrogenation reactions at room temperature. PMID:27258184

  19. Alloying effects on hydrogen permeability of V without catalytic Pd overlayer

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Y.; Yukawa, H.; Suzuki, A. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Nambu, T. [Department of Materials Science and Engineering, Suzuka National College of Technology, Shiroko-cho, Suzuka, Mie 510-0294 (Japan); Matsumoto, Y. [Department of Mechanical Engineering, Oita National College of Technology, Maki, Oita 870-0152 (Japan); Murata, Y. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan)

    2015-10-05

    Highlights: • Air–treated V–based alloy membranes without catalytic Pd overlayer are found to possess excellent hydrogen permeability. • They also exhibit good durability at high temperature. • Alloying effects are discussed in view of the new description of hydrogen permeation based on hydrogen chemical potential. - Abstract: Hydrogen permeability of air–treated V–based alloy membranes without Pd coating have been investigated. The diffusion–limiting hydrogen permeation reaction takes place even without catalytic Pd overlayer on the surface. It is shown that pure V and its alloy membranes without Pd overlayer possess excellent hydrogen permeability and good durability at high temperature. The new description of hydrogen permeation based on hydrogen chemical potential has been applied and the hydrogen flux is analyzed in terms of the mobility of hydrogen atom and the PCT factor, f{sub PCT}.

  20. Hydrogen Production Technical Team Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-06-01

    The Hydrogen Production Technical Team Roadmap identifies research pathways leading to hydrogen production technologies that produce near-zero net greenhouse gas (GHG) emissions from highly efficient and diverse renewable energy sources. This roadmap focuses on initial development of the technologies, identifies their gaps and barriers, and describes activities by various U.S. Department of Energy (DOE) offices to address the key issues and challenges.

  1. Technical Analysis of Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Ali T-Raissi

    2005-01-14

    The aim of this work was to assess issues of cost, and performance associated with the production and storage of hydrogen via following three feedstocks: sub-quality natural gas (SQNG), ammonia (NH{sub 3}), and water. Three technology areas were considered: (1) Hydrogen production utilizing SQNG resources, (2) Hydrogen storage in ammonia and amine-borane complexes for fuel cell applications, and (3) Hydrogen from solar thermochemical cycles for splitting water. This report summarizes our findings with the following objectives: Technoeconomic analysis of the feasibility of the technology areas 1-3; Evaluation of the hydrogen production cost by technology areas 1; and Feasibility of ammonia and/or amine-borane complexes (technology areas 2) as a means of hydrogen storage on-board fuel cell powered vehicles. For each technology area, we reviewed the open literature with respect to the following criteria: process efficiency, cost, safety, and ease of implementation and impact of the latest materials innovations, if any. We employed various process analysis platforms including FactSage chemical equilibrium software and Aspen Technologies AspenPlus and HYSYS chemical process simulation programs for determining the performance of the prospective hydrogen production processes.

  2. Surface Structure and Catalytic Performance of Ni-Fe Catalyst for Low-Temperature CO Hydrogenation

    Directory of Open Access Journals (Sweden)

    Fanhui Meng

    2014-01-01

    Full Text Available Catalysts 16NixFe/Al2O3 (x is 0, 1, 2, 4, 6, 8 were prepared by incipient wetness impregnation method and the catalytic performance for the production of synthetic natural gas (SNG from CO hydrogenation in slurry-bed reactor were studied. The catalysts were characterized by BET, XRD, UV-Vis DRS, H2-TPR, CO-TPD, and XPS, and the results showed that the introduction of iron improved the dispersion of Ni species, weakened the interaction between Ni species and support and decreased the reduction temperature and that catalyst formed Ni-Fe alloy when the content of iron exceeded 2%. Experimental results revealed that the addition of iron to the catalyst can effectively improve the catalytic performance of low-temperature CO methanation. Catalyst 16Ni4Fe/Al2O3 with the iron content of 4% exhibited the best catalytic performance, the conversion of CO and the yield of CH4 reached 97.2% and 84.9%, respectively, and the high catalytic performance of Ni-Fe catalyst was related to the property of formed Ni-Fe alloy. Further increase of iron content led to enhancing the water gas shift reaction.

  3. Biological hydrogen production from phytomass

    Energy Technology Data Exchange (ETDEWEB)

    Bartacek, J.; Zabranska, J. [Inst. of Chemical Technology, Prague (Czech Republic). Dept. of Water Technology and Environmental Engineering

    2004-07-01

    Renewable sources of energy have received wide attention lately. One candidate is hydrogen which has the added advantage of involving no greenhouse gases. Biological hydrogen production from wastewater or biowastes is a very attractive production technique. So far, most studies have concentrated on the use of photosynthetic bacteria. However, dark fermentation has recently become a popular topic of research as it has the advantage of not requiring light energy input, something that limits the performance of the photosynthetic method. While pure cultures have been used in most of the investigations to date, in industrial situations mixed cultures will probably be the norm because of unavoidable contamination. In this investigation the phytomass of amaranth (Amaranthus cruentus L) was used to produce hydrogen. Specific organic loading, organic loading, and pH were varied to study the effect on hydrogen production. 18 refs., 1 tab., 6 figs.

  4. Catalytic Hydrogenation of Organic Compounds without H2 Supply: An Electrochemical System

    Science.gov (United States)

    Navarro, Daniela Maria do Amaral Ferraz; Navarro, Marcelo

    2004-01-01

    An experiment developed for an undergraduate organic chemistry laboratory course that can be used to introduce the catalytic hydrogenation reaction, catalysis electrochemical principles and gas chromatography is presented. The organic compounds hydrogenated by the electrocatalytic hydrogenation (ECH) process were styrene, benzaldehyde and…

  5. Hydrogen production processes: an overview

    International Nuclear Information System (INIS)

    Hydrogen, the most abundant element in the universe, does not occur freely on our planet. However, it is predominantly present on earth in combination with oxygen as water and with carbon and other elements as fossil fuels, hydrocarbons, and biomass. Production of hydrogen from these sources is an energy intensive process. Hydrogen production processes can be broadly classified into three general categories: thermal, electrolytic, and photolytic. At present about 96 % of world's hydrogen is produced from fossil fuels using thermal processes like steam methane reforming, partial oxidation, and gasification of coal or biomass while remaining comes from electrolysis of water. Most of the hydrogen produced is primarily used in the chemical industry. More recently hydrogen is perceived as a clean, renewable energy carrier for sustainable energy supply in the future especially when issues like growing concern about global warming due to emission of green house gases and depletion of fossil fuel resources have become paramount. In association with the fuel cell technology, hydrogen appears to be a promising alternative to the fossil fuels for transport applications

  6. Solar Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Koval, C. [Univ. of Colorado, Boulder (United States); Sutin, N. [Brookhaven National Lab., Upton, NY (United States); Turner, J. [National Renewable Energy Lab., Golden, CO (United States)

    1996-09-01

    This panel addressed different methods for the photoassisted dissociation of water into its component parts, hydrogen and oxygen. Systems considered include PV-electrolysis, photoelectrochemical cells, and transition-metal based microheterogeneous and homogeneous systems. While none of the systems for water splitting appear economically viable at the present time, the panel identified areas of basic research that could increase the overall efficiency and decrease the costs. Common to all the areas considered was the underlying belief that the water-to-hydrogen half reaction is reasonably well characterized, while the four-electron oxidation of water-to-oxygen is less well understood and represents a significant energy loss. For electrolysis, research in electrocatalysis to reduce overvoltage losses was identified as a key area for increased efficiency. Non-noble metal catalysts and less expensive components would reduce capital costs. While potentially offering higher efficiencies and lower costs, photoelectrochemical-based direct conversion systems undergo corrosion reactions and often have poor energetics for the water reaction. Research is needed to understand the factors that control the interfacial energetics and the photoinduced corrosion. Multi-photon devices were identified as promising systems for high efficiency conversion.

  7. Complexes of earth-abundant metals for catalytic electrochemical hydrogen generation under aqueous conditions.

    Science.gov (United States)

    Thoi, V Sara; Sun, Yujie; Long, Jeffrey R; Chang, Christopher J

    2013-03-21

    Growing global energy demands and climate change motivate the development of new renewable energy technologies. In this context, water splitting using sustainable energy sources has emerged as an attractive process for carbon-neutral fuel cycles. A key scientific challenge to achieving this overall goal is the invention of new catalysts for the reductive and oxidative conversions of water to hydrogen and oxygen, respectively. This review article will highlight progress in molecular electrochemical approaches for catalytic reduction of protons to hydrogen, focusing on complexes of earth-abundant metals that can function in pure aqueous or mixed aqueous-organic media. The use of water as a reaction medium has dual benefits of maintaining high substrate concentration as well as minimizing the environmental impact from organic additives and by-products. PMID:23034627

  8. Complexes of earth-abundant metals for catalytic electrochemical hydrogen generation under aqueous conditions.

    Science.gov (United States)

    Thoi, V Sara; Sun, Yujie; Long, Jeffrey R; Chang, Christopher J

    2013-03-21

    Growing global energy demands and climate change motivate the development of new renewable energy technologies. In this context, water splitting using sustainable energy sources has emerged as an attractive process for carbon-neutral fuel cycles. A key scientific challenge to achieving this overall goal is the invention of new catalysts for the reductive and oxidative conversions of water to hydrogen and oxygen, respectively. This review article will highlight progress in molecular electrochemical approaches for catalytic reduction of protons to hydrogen, focusing on complexes of earth-abundant metals that can function in pure aqueous or mixed aqueous-organic media. The use of water as a reaction medium has dual benefits of maintaining high substrate concentration as well as minimizing the environmental impact from organic additives and by-products.

  9. The hydrogen production; La production d'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Aujollet, P.; Goldstein, St. [CEA Cadarach, Dir. de l' Energie Nucleaire, 13 - Saint Paul lez Durance (France); Lucchese, P. [CEA Fontenay aux Roses, Dir. des Nouvelles Technologies de l' Energie, 92 (France)

    2002-07-01

    This paper gives an overview on the implementing of the hydrogen as substitution fuel in the transportation sector. It presents also the problems of this fuel storage and exploitation and describes the production modes and their safety. It also presents the main lines of the japan HTGR program. (A.L.B.)

  10. Photoelectrochemical Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian

    2013-12-23

    The objectives of this project, covering two phases and an additional extension phase, were the development of thin film-based hybrid photovoltaic (PV)/photoelectrochemical (PEC) devices for solar-powered water splitting. The hybrid device, comprising a low-cost photoactive material integrated with amorphous silicon (a-Si:H or a-Si in short)-based solar cells as a driver, should be able to produce hydrogen with a 5% solar-to-hydrogen conversion efficiency (STH) and be durable for at least 500 hours. Three thin film material classes were studied and developed under this program: silicon-based compounds, copper chalcopyrite-based compounds, and metal oxides. With the silicon-based compounds, more specifically the amorphous silicon carbide (a-SiC), we achieved a STH efficiency of 3.7% when the photoelectrode was coupled to an a-Si tandem solar cell, and a STH efficiency of 6.1% when using a crystalline Si PV driver. The hybrid PV/a-SiC device tested under a current bias of -3~4 mA/cm{sup 2}, exhibited a durability of up to ~800 hours in 0.25 M H{sub 2}SO{sub 4} electrolyte. Other than the PV driver, the most critical element affecting the photocurrent (and hence the STH efficiency) of the hybrid PV/a-SiC device was the surface energetics at the a-SiC/electrolyte interface. Without surface modification, the photocurrent of the hybrid PEC device was ~1 mA/cm{sup 2} or lower due to a surface barrier that limits the extraction of photogenerated carriers. We conducted an extensive search for suitable surface modification techniques/materials, of which the deposition of low work function metal nanoparticles was the most successful. Metal nanoparticles of ruthenium (Ru), tungsten (W) or titanium (Ti) led to an anodic shift in the onset potential. We have also been able to develop hybrid devices of various configurations in a monolithic fashion and optimized the current matching via altering the energy bandgap and thickness of each constituent cell. As a result, the short

  11. Hydrogen production from glucose in ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Assenbaum, D.W.; Taccardi, N.; Berger, M.E.M.; Boesmann, A.; Enzenberger, F.; Woelfel, R.; Wasserscheid, P. [Erlangen-Nuernberg Univ. (Germany). Lehrstuhl fuer chemische Reaktionstechnik

    2010-07-01

    Depletion of oil and gas reserves and growing global warming concerns have created a world-wide interest in new concepts for future sustainable energy supplies. The development of effective ways to produce hydrogen from biomass is expected to be one important contribution to such a goal [1]. Nowadays, three main processes are considered for future industrial application, namely: gasification of biomass [2], reforming in supercritical water [3] and aqueous phase reforming [4,5]. Other technologies such as enzymatic decomposition of sugars or steam reforming of bio-oils suffer from low hydrogen production rates and/or complex processing requirements and can probably not be considered for industrial applications in the closer future [6,7]. On the other hand, either the gasification of biomass, which is typically carried out at temperatures above 800 C using Ni or Fe catalysts [8,9,10,11], or the reforming in supercritical water, which is typically carried out in presence of Ru catalyst at pressures of 300bar and temperatures ranging from 500 to 700 C [12], suffer of poor energetic efficiency as a lot of energy is required to run the reactions. More recently, an alternative to the two aforementioned high temperature processes has been proposed as ''aqueous phase reforming'' (APR) by Dumesic and coworkers [13,14,15,16,17]. They achieved the reforming of polyols (such as ethylene glycol, glycerol and sorbitol) using heterogeneous catalysts at temperatures between 200 and 250 C and pressure typically between 15-50bar.The temperature level of the reaction allows generating hydrogen with low amounts of CO in a single reactor. The process typically forms 35 % of hydrogen, 40 % of CO2 and 25 % of combined alkanes. The high amount of formed alkanes originates eventually from CO hydrogenation and Fischer-Tropsch (F-T) reaction [18,19,20,21], those are thermodynamically favored in the above mentioned conditions. However, heterogeneously catalyzed APR

  12. Photoelectrochemical Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian

    2013-12-23

    The objectives of this project, covering two phases and an additional extension phase, were the development of thin film-based hybrid photovoltaic (PV)/photoelectrochemical (PEC) devices for solar-powered water splitting. The hybrid device, comprising a low-cost photoactive material integrated with amorphous silicon (a-Si:H or a-Si in short)-based solar cells as a driver, should be able to produce hydrogen with a 5% solar-to-hydrogen conversion efficiency (STH) and be durable for at least 500 hours. Three thin film material classes were studied and developed under this program: silicon-based compounds, copper chalcopyrite-based compounds, and metal oxides. With the silicon-based compounds, more specifically the amorphous silicon carbide (a-SiC), we achieved a STH efficiency of 3.7% when the photoelectrode was coupled to an a-Si tandem solar cell, and a STH efficiency of 6.1% when using a crystalline Si PV driver. The hybrid PV/a-SiC device tested under a current bias of -3~4 mA/cm{sup 2}, exhibited a durability of up to ~800 hours in 0.25 M H{sub 2}SO{sub 4} electrolyte. Other than the PV driver, the most critical element affecting the photocurrent (and hence the STH efficiency) of the hybrid PV/a-SiC device was the surface energetics at the a-SiC/electrolyte interface. Without surface modification, the photocurrent of the hybrid PEC device was ~1 mA/cm{sup 2} or lower due to a surface barrier that limits the extraction of photogenerated carriers. We conducted an extensive search for suitable surface modification techniques/materials, of which the deposition of low work function metal nanoparticles was the most successful. Metal nanoparticles of ruthenium (Ru), tungsten (W) or titanium (Ti) led to an anodic shift in the onset potential. We have also been able to develop hybrid devices of various configurations in a monolithic fashion and optimized the current matching via altering the energy bandgap and thickness of each constituent cell. As a result, the short

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

    Science.gov (United States)

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

    2015-12-01

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

  14. Microbial hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, P.F.; Maness, P.C.; Martin, S. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1995-09-01

    Photosynthetic bacteria inhabit an anaerobic or microaerophilic world where H{sub 2} is produced and consumed as a shared intermediary metabolite. Within a given bacterial isolate there are as many as 4 to 6 distinct enzymes that function to evolve or consume H{sub 2}. Three of the H{sub 2}-evolving physiologies involving three different enzymes from photosynthetic bacteria have been examined in detail for commercial viability. Nitrogenase-mediated H{sub 2} production completely dissimilates many soluble organic compounds to H{sub 2} and CO{sub 2} at rates up to 131 {mu}mol H{sub 2}{sm_bullet}min{sup -1}{sm_bullet}g cdw{sup -1} and can remain active for up to 20 days. This metabolism is very energy intensive, however, which limits solar conversion efficiencies. Fermentative hydrogenase can produce H{sub 2} at rates of 440 {mu}mol{sm_bullet}min{sup -1}{sm_bullet}g cdw{sup -1} at low levels of irradiation over indefinite periods. The equilibrium for this activity is low (<0.15 atmospheres), thereby requiring gas sparging, vacuuming, or microbial scavenging to retain prolonged activity. Microbial H{sub 2} production from the CO component of synthesis or producer gases maximally reaches activities of 1.5 mmol{sm_bullet}min{sup -1}{sm_bullet}g cdw{sup -1}. Mass transport of gaseous CO into an aqueous bacterial suspension is the rate-limiting step. Increased gas pressure strongly accelerates these rates. Immobilized bacteria on solid supports at ambient pressures also show enhanced shift activity when the bulk water is drained away. Scaled-up bioreactors with 100-200 cc bed volume have been constructed and tested. The near-term goal of this portion of the project is to engineer and economically evaluate a prototype system for the biological production of H{sub 2} from biomass. The CO shift enables a positive selection technique for O{sub 2}-resistant, H{sub 2}-evolving bacterial enzymes from nature.

  15. Production of hydrogen by thermocatalytic cracking of natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Muradov, N.Z. [Univ. of Central Florida, Cape Canaveral, FL (United States)

    1995-09-01

    It is universally accepted that in the next few decades hydrogen production will continue to rely on fossil fuels (primarily, natural gas). On the other hand, the conventional methods of hydrogen production from natural gas (for example, steam reforming) are complex multi-step processes. These processes also result in the emission of large quantities of CO{sub 2} into the atmosphere that produce adverse ecological effects. One alternative is the one-step thermocatalytic cracking (TCC) (or decomposition) of natural gas into hydrogen and carbon. Preliminary analysis indicates that the cost of hydrogen produced by thermal decomposition of natural gas is somewhat lower than the conventional processes after by-product carbon credit is taken. In the short term, this process can be used for on-site production of hydrogen-methane mixtures in gas-filling stations and for CO{sub x}-free production of hydrogen for fuel cell driven prime movers. The experimental data on the thermocatalytic cracking of methane over various catalysts and supports in a wide range of temperatures (500-900{degrees}C) are presented in this paper. Two types of reactors were designed and built at FSEC: continuous flow and pulse fix bed catalytic reactors. The temperature dependence of the hydrogen production yield using oxide type catalysts was studied. Alumina-supported Ni- and Fe-catalysts demonstrated relatively high efficiency in the methane cracking reaction at moderate temperatures (600-800{degrees}C). Kinetic curves of hydrogen production over metal and metal oxide catalysts at different temperatures are presented in the paper. Fe-catalyst demonstrated good stability (for several hours), whereas alumina-supported Pt-catalyst rapidly lost its catalytic activity.

  16. Hydrogen Storage and Production Project

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, Abhijit [Univ. of Arkansas, Little Rock, AR (United States); Biris, A. S. [Univ. of Arkansas, Little Rock, AR (United States); Mazumder, M. K. [Univ. of Arkansas, Little Rock, AR (United States); Karabacak, T. [Univ. of Arkansas, Little Rock, AR (United States); Kannarpady, Ganesh [Univ. of Arkansas, Little Rock, AR (United States); Sharma, R. [Univ. of Arkansas, Little Rock, AR (United States)

    2011-07-31

    This is the final technical report. This report is a summary of the project. The goal of our project is to improve solar-to-hydrogen generation efficiency of the PhotoElectroChemical (PEC) conversion process by developing photoanodes with high absorption efficiency in the visible region of the solar radiation spectrum and to increase photo-corrosion resistance of the electrode for generating hydrogen from water. To meet this goal, we synthesized nanostructured heterogeneous semiconducting photoanodes with a higher light absorption efficiency compared to that of TiO2 and used a corrosion protective layer of TiO2. While the advantages of photoelectrochemical (PEC) production of hydrogen have not yet been realized, the recent developments show emergence of new nanostructural designs of photoanodes and choices of materials with significant gains in photoconversion efficiency.

  17. Hydrogen Production in Fusion Reactors

    OpenAIRE

    Sudo, S.; Tomita, Y.; Yamaguchi, S.; Iiyoshi, A.; Momota, H.; Motojima, O.; Okamoto, M; Ohnishi, M.; Onozuka, M.; Uenosono, C.

    1993-01-01

    As one of methods of innovative energy production in fusion reactors without having a conventional turbine-type generator, an efficient use of radiation produced in a fusion reactor with utilizing semiconductor and supplying clean fuel in a form of hydrogen gas are studied. Taking the candidates of reactors such as a toroidal system and an open system for application of the new concepts, the expected efficiency and a concept of plant system are investigated.

  18. Low Cost Hydrogen Production Platform

    Energy Technology Data Exchange (ETDEWEB)

    Timothy M. Aaron, Jerome T. Jankowiak

    2009-10-16

    A technology and design evaluation was carried out for the development of a turnkey hydrogen production system in the range of 2.4 - 12 kg/h of hydrogen. The design is based on existing SMR technology and existing chemical processes and technologies to meet the design objectives. Consequently, the system design consists of a steam methane reformer, PSA system for hydrogen purification, natural gas compression, steam generation and all components and heat exchangers required for the production of hydrogen. The focus of the program is on packaging, system integration and an overall step change in the cost of capital required for the production of hydrogen at small scale. To assist in this effort, subcontractors were brought in to evaluate the design concepts and to assist in meeting the overall goals of the program. Praxair supplied the overall system and process design and the subcontractors were used to evaluate the components and system from a manufacturing and overall design optimization viewpoint. Design for manufacturing and assembly (DFMA) techniques, computer models and laboratory/full-scale testing of components were utilized to optimize the design during all phases of the design development. Early in the program evaluation, a review of existing Praxair hydrogen facilities showed that over 50% of the installed cost of a SMR based hydrogen plant is associated with the high temperature components (reformer, shift, steam generation, and various high temperature heat exchange). The main effort of the initial phase of the program was to develop an integrated high temperature component for these related functions. Initially, six independent concepts were developed and the processes were modeled to determine overall feasibility. The six concepts were eventually narrowed down to the highest potential concept. A US patent was awarded in February 2009 for the Praxair integrated high temperature component design. A risk analysis of the high temperature component was

  19. SYNTHESIS AND CHARACTERIZATION OF A SILICA-SUPPORTED CARBOXYMETHYLCELLULOSE PLATINUM COMPLEX AND ITS CATALYTIC BEHAVIORS FOR HYDROGENATION OF AROMATICS

    Institute of Scientific and Technical Information of China (English)

    TANG Liming; HUANG Meiyu; JIANG Yingyan

    1996-01-01

    A silica-supported carboxymethylcellulose platinum complex (abbreviated as SiO2-CMC-Pt) has been prepared and characterized by XPS. Its catalytic properties for hydrogenation of aromatic compounds were studied. The results showed that this catalyst could catalyze the hydrogenation of phenol, anisol, p-cresol, benzene and toluene to cyclohexanol, cyclohexyl methyl ether, p-methyl cyclohexanol, cyclohexane and methylcyclohexane, respectively in 100% yield at 30℃ and 1 atm. In the hydrogenation of phenol,COO/Pt ratio in SiO2-CMC-Pt has much influence on the initial hydrogenation rate and the selectivity for the intermediate product, cyclohexanone. The highest initial rate and the highest yield of cyclohexanone both occur at COO/Pt ratio of 6. The complex is stable during the reaction and can be used repeatedly.

  20. Hydrogen production processes; Procedes de production d'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The goals of this first Gedepeon workshop on hydrogen production processes are: to stimulate the information exchange about research programs and research advances in the domain of hydrogen production processes, to indicate the domains of interest of these processes and the potentialities linked with the coupling of a nuclear reactor, to establish the actions of common interest for the CEA, the CNRS, and eventually EDF, that can be funded in the framework of the Gedepeon research group. This document gathers the slides of the 17 presentations given at this workshop and dealing with: the H{sub 2} question and the international research programs (Lucchese P.); the CEA's research program (Lucchese P., Anzieu P.); processes based on the iodine/sulfur cycle: efficiency of a facility - flow-sheets, efficiencies, hard points (Borgard J.M.), R and D about the I/S cycle: Bunsen reaction (Colette S.), R and D about the I/S cycle: the HI/I{sub 2}/H{sub 2}O system (Doizi D.), demonstration loop/chemical engineering (Duhamet J.), materials and corrosion (Terlain A.); other processes under study: the Westinghouse cycle (Eysseric C.), other processes under study at the CEA (UT3, plasma,...) (Lemort F.), database about thermochemical cycles (Abanades S.), Zn/ZnO cycle (Broust F.), H{sub 2} production by cracking, high temperature reforming with carbon trapping (Flamant G.), membrane technology (De Lamare J.); high-temperature electrolysis: SOFC used as electrolyzers (Grastien R.); generic aspects linked with hydrogen production: technical-economical evaluation of processes (Werkoff F.), thermodynamic tools (Neveu P.), the reactor-process coupling (Aujollet P.). (J.S.)

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

    Science.gov (United States)

    Quintard, Adrien; Rodriguez, Jean

    2016-08-18

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

  2. Advances in ethanol reforming for the production of hydrogen

    Directory of Open Access Journals (Sweden)

    Laura Guerrero

    2014-06-01

    Full Text Available Catalytic steam reforming of ethanol (SRE is a promising route for the production of renewable hydrogen (H2. This article reviews the influence of doping supported-catalysts used in SRE on the conversion of ethanol, selectivity for H2, and stability during long reaction periods. In addition, promising new technologies such as membrane reactors and electrochemical reforming for performing SRE are presented.

  3. C12A7-Mg催化剂水蒸汽重整生物油、石脑油和CH4制氢%Hydrogen Production by Catalytic Steam Reforming of Bio-oil, Naphtha and CH4 over C12A7-Mg Catalyst

    Institute of Scientific and Technical Information of China (English)

    潘越; 王兆祥; 阚涛; 朱锡峰; 李全新

    2006-01-01

    Hydrogen production by catalytic steam reforming of the bio-oil, naphtha, and CH4 was investigated over a novel metal-doped catalyst of (Ca24Al28O64)4+.4O-/Mg (C12A7-Mg). The catalytic steam reforming was investigated from 250 to 850 ℃ in the fixed-bed continuous flow reactor. For the reforming of bio-oil, the yield of hydrogen of 80% was obtained at 750 ℃, and the maximum carbon conversion is nearly close to 95% under the optimum steam reforming condition. For the reforming of naphtha and CH4, the hydrogen yield and carbon conversion are lower than that of bio-oil at the same temperature. The characteristics of catalyst were also investigated by XPS. The catalyst deactivation was mainly caused by the deposition of carbon in the catalytic steam reforming process.%利用自制的C12A7-Mg催化剂,研究了催化水蒸汽重整生物油、石脑油和CH4制备氢气的性能,以及催化剂寿命,并用X射线光电子能谱对催化剂进行了表征.温度测试范围为250~850℃.对于催化水蒸汽重整生物油反应,在750℃时,氢气产率最大达到80%,碳的转化率接近95%.在相同的反应温度下,催化水蒸汽重整石脑油和CH4的氢气产率和碳的转化率要低于重整生物油反应.催化剂的失活主要是由于重整过程中的积碳.

  4. Demonstration of the Catalytic Decomposition of Hydrogen Peroxide.

    Science.gov (United States)

    Conklin, Alfred R. Jr.; Kessinger, Angela

    1996-01-01

    Describes a demonstration known as Elephant's Toothpaste in which the decomposition of hydrogen peroxide is catalyzed by iodide. Oxygen is released and soap bubbles are produced. The foam produced is measured, and results show a good relationship between the amount of foam and the concentration of the hydrogen peroxide. (DDR)

  5. Application of microscopy technology in thermo-catalytic methane decomposition to hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Irene Lock Sow, E-mail: irene.sowmei@gmail.com; Lock, S. S. M., E-mail: serenelock168@gmail.com; Abdullah, Bawadi, E-mail: bawadi-abdullah@petronas.com.my [Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Sri Iskandar, 31750, Perak (Malaysia)

    2015-07-22

    Hydrogen production from the direct thermo-catalytic decomposition of methane is a promising alternative for clean fuel production because it produces pure hydrogen without any CO{sub x} emissions. However, thermal decomposition of methane can hardly be of any practical and empirical interest in the industry unless highly efficient and effective catalysts, in terms of both specific activity and operational lifetime have been developed. In this work, bimetallic Ni-Pd on gamma alumina support have been developed for methane cracking process by using co-precipitation and incipient wetness impregnation method. The calcined catalysts were characterized to determine their morphologies and physico-chemical properties by using Brunauer-Emmett-Teller method, Field Emission Scanning Electron Microscopy, Energy-dispersive X-ray spectroscopy and Thermogravimetric Analysis. The results suggested that that the catalyst which is prepared by the co-precipitation method exhibits homogeneous morphology, higher surface area, have uniform nickel and palladium dispersion and higher thermal stability as compared to the catalyst which is prepared by wet impregnation method. This characteristics are significant to avoid deactivation of the catalysts due to sintering and carbon deposition during methane cracking process.

  6. Catalytic hydrogenation using complexes of base metals with tridentate ligands

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Kalyan V.; Zhang, Guoqi; Hanson, Susan K.

    2016-09-06

    Complexes of cobalt and nickel with tridentate ligand PNHP.sup.R are effective for hydrogenation of unsaturated compounds. Cobalt complex [(PNHP.sup.Cy)Co(CH.sub.2SiMe.sub.3)]BAr.sup.F.sub.4 (PNHP.sup.Cy=bis[2-(dicyclohexylphosphino)ethyl]amine, BAr.sup.F.sub.4=B(3,5-(CF.sub.3).sub.2C.sub.6H.sub.3).sub.4)) was prepared and used with hydrogen for hydrogenation of alkenes, aldehydes, ketones, and imines under mild conditions (25-60.degree. C., 1-4 atm H.sub.2). Nickel complex [(PNHP.sup.Cy)Ni(H)]BPh.sub.4 was used for hydrogenation of styrene and 1-octene under mild conditions. (PNP.sup.Cy)Ni(H) was used for hydrogenating alkenes.

  7. Supported catalysts based on layered double hydroxides for catalytic oxidation and hydrogenation: general functionality and promising application prospects.

    Science.gov (United States)

    Feng, Junting; He, Yufei; Liu, Yanan; Du, Yiyun; Li, Dianqing

    2015-08-01

    Oxidation and hydrogenation catalysis plays a crucial role in the current chemical industry for the production of key chemicals and intermediates. Because of their easy separation and recyclability, supported catalysts are widely used in these two processes. Layered double hydroxides (LDHs) with the advantages of unique structure, composition diversity, high stability, ease of preparation and low cost have shown great potential in the design and synthesis of novel supported catalysts. This review summarizes the recent progress in supported catalysts by using LDHs as supports/precursors for catalytic oxidation and hydrogenation. Particularly, partial hydrogenation of acetylene, hydrogenation of dimethyl terephthalate, methanation, epoxidation of olefins, elimination of NOx and SOx emissions, and selective oxidation of biomass have been chosen as representative reactions in the petrochemical, fine chemicals, environmental protection and clean energy fields to highlight the potential application and the general functionality of LDH-based catalysts in catalytic oxidation and hydrogenation. Finally, we concisely discuss some of the scientific challenges and opportunities of supported catalysts based on LDH materials. PMID:25962432

  8. Hydrogen Generation from Catalytic Steam Reforming of Acetic Acid by Ni/Attapulgite Catalysts

    Directory of Open Access Journals (Sweden)

    Yishuang Wang

    2016-11-01

    Full Text Available In this research, catalytic steam reforming of acetic acid derived from the aqueous portion of bio-oil for hydrogen production was investigated using different Ni/ATC (Attapulgite Clay catalysts prepared by precipitation, impregnation and mechanical blending methods. The fresh and reduced catalysts were characterized by XRD, N2 adsorption–desorption, TEM and temperature program reduction (H2-TPR. The comprehensive results demonstrated that the interaction between active metallic Ni and ATC carrier was significantly improved in Ni/ATC catalyst prepared by precipitation method, from which the mean of Ni particle size was the smallest (~13 nm, resulting in the highest metal dispersion (7.5%. The catalytic performance of the catalysts was evaluated by the process of steam reforming of acetic acid in a fixed-bed reactor under atmospheric pressure at two different temperatures: 550 °C and 650 °C. The test results showed the Ni/ATC prepared by way of precipitation method (PM-Ni/ATC achieved the highest H2 yield of ~82% and a little lower acetic acid conversion efficiency of ~85% than that of Ni/ATC prepared by way of impregnation method (IM-Ni/ATC (~95%. In addition, the deactivation catalysts after reaction for 4 h were analyzed by XRD, TGA-DTG and TEM, which demonstrated the catalyst deactivation was not caused by the amount of carbon deposition, but owed to the significant agglomeration and sintering of Ni particles in the carrier.

  9. Solar based hydrogen production systems

    CERN Document Server

    Dincer, Ibrahim

    2013-01-01

    This book provides a comprehensive analysis of various solar based hydrogen production systems. The book covers first-law (energy based) and second-law (exergy based) efficiencies and provides a comprehensive understanding of their implications. It will help minimize the widespread misuse of efficiencies among students and researchers in energy field by using an intuitive and unified approach for defining efficiencies. The book gives a clear understanding of the sustainability and environmental impact analysis of the above systems. The book will be particularly useful for a clear understanding

  10. Nuclear energy for hydrogen production

    International Nuclear Information System (INIS)

    In the long term, H2 production technologies will be strongly focusing on CO2-neutral or CO2-free methods. Nuclear with its virtually no air-borne pollutants emissions appears to be an ideal option for large-scale centralized H2 production. It will be driven by major factors such as production rates of fossil fuels, political decisions on greenhouse gas emissions, energy security and independence of foreign oil uncertainties, or the economics of large-scale hydrogen production and transmission. A nuclear reactor operated in the heat and power cogeneration mode must be located in close vicinity to the consumer's site, i.e., it must have a convincing safety concept of the combined nuclear/ chemical production plant. A near-term option of nuclear hydrogen production which is readily available is conventional low temperature electrolysis using cheap off-peak electricity from present nuclear power plants. This, however, is available only if the share of nuclear in power production is large. But as fossil fuel prices will increase, the use of nuclear outside base-load becomes more attractive. Nuclear steam reforming is another important near-term option for both the industrial and the transportation sector, since principal technologies were developed, with a saving potential of some 35 % of methane feedstock. Competitiveness will benefit from increasing cost level of natural gas. The HTGR heated steam reforming process which was simulated in pilot plants both in Germany and Japan, appears to be feasible for industrial application around 2015. A CO2 emission free option is high temperature electrolysis which reduces the electricity needs up to about 30 % and could make use of high temperature heat and steam from an HTGR. With respect to thermochemical water splitting cycles, the processes which are receiving presently most attention are the sulfur-iodine, the Westinghouse hybrid, and the calcium-bromine (UT-3) cycles. Efficiencies of the S-I process are in the range of 33

  11. GTI's hydrogen programs: hydrogen production, storage, and applications

    Institute of Scientific and Technical Information of China (English)

    范钦柏

    2006-01-01

    The use of hydrogen as an energy carrier could help address our concerns about energy security, global climate change,and air quality. Fuel cells are an important enabling technology for the Hydrogen Future and have the potential to revolutionize theway we power our nation, offering cleaner, more-efficient alternatives to the combustion of gasoline and other fossil fuels.For over 45 years, GTI has been active in hydrogen energy research, development and demonstration. The Institute has extensive experience and on-going work in all aspects of the hydrogen energy economy including production, delivery, infrastructure,use, safety and public policy. This paper discusses the recent GTI programs in hydrogen production, hydrogen storage, and proton exchange membrane fuel cells (PEMFC) and solid oxide fuel cells (SOFC).

  12. Maximizing hydrogen production by cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Bothe, H.; Winkelmann, S.; Boison, G. [Botanical Inst., The Univ. of Cologne, Cologne (Germany)

    2008-03-15

    When incubated anaerobically, in the light, in the presence of C{sub 2}H{sub 2} and high concentrations of H{sub 2}, both Mo-grown Anabaena variabilis and either Mo- or V-grown Anabaena azotica produce large amounts of H{sub 2} in addition to the H{sub 2} initially added. In contrast, C{sub 2}H{sub 2}-reduction is diminished under these conditions. The additional H{sub 2}-production mainly originates from nitrogenase with the V-enzyme being more effective than the Mo-protein. This enhanced H{sub 2}-production in the presence of added H{sub 2} and C{sub 2}H{sub 2} should be of interest in approaches to commercially exploit solar energy conversion by cyanobacterial photosynthesis for the generation of molecular hydrogen as a clean energy source. (orig.)

  13. Production of hydrogen by thermocatalytic cracking of natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Muradov, N. [Florida Solar Energy Center, Cocoa, FL (United States)

    1996-10-01

    The conventional methods of hydrogen production from natural gas (for example, steam reforming and partial oxidation) are complex, multi-step processes that produce large quantities of CO{sub 2}. The main goal of this project is to develop a technologically simple process for hydrogen production from natural gas (NG) and other hydrocarbon fuels via single-step decomposition of hydrocarbons. This approach eliminates or significantly reduces CO{sub 2} emission. Carbon is a valuable by-product of this process, whereas conventional methods of hydrogen production from NG produce no useful by-products. This approach is based on the use of special catalysts that reduce the maximum temperature of the process from 1400-1500{degrees}C (thermal non-catalytic decomposition of methane) to 500-900{degrees}C. Transition metal based catalysts and various forms of carbon are among the candidate catalysts for the process. This approach can advantageously be used for the development of compact NG reformers for on-site production of hydrogen-methane blends at refueling stations and, also, for the production of hydrogen-rich gas for fuel cell applications. The author extended the search for active methane decomposition catalysts to various modifications of Ni-, Fe-, Mo- and Co-based catalysts. Variation in the operational parameters makes it possible to produce H{sub 2}-CH{sub 4} blends with a wide range of hydrogen concentrations that vary from 15 to 98% by volume. The author found that Ni-based catalysts are more effective at temperatures below 750{degrees}C, whereas Fe-based catalysts are effective at temperatures above 800{degrees}C for the production of hydrogen with purity of 95% v. or higher. The catalytic pyrolysis of liquid hydrocarbons (pentane, gasoline) over Fe-based catalyst was conducted. The author observed the production of a hydrogen-rich gas (hydrogen concentration up to 97% by volume) at a rate of approximately 1L/min.mL of hydrocarbon fuel.

  14. Carbon Dioxide Conversion to Valuable Chemical Products over Composite Catalytic Systems

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, Robert A.; Hu, Jianli; Jones, Susanne B.; Wilcox, Wayne A.; Frye, John G.; White, J. F.; Jiang, Juyuan; Wang, Yong

    2013-05-01

    Presented is an experimental study on catalytic conversion of carbon dioxide into methanol, ethanol and acetic acid. Catalysts having different catalytic functions were synthesized and combined in different ways to enhance selectivity to desired products. The combined catalyst system possessed the following functions: methanol synthesis, Fischer-Tropsch synthesis, water-gas-shift and hydrogenation. Results showed that the methods of integrating these catalytic functions played important role in achieving desired product selectivity. It was speculated that if methanol synthesis sites were located adjacent to the C-C chain growth sites, the formation rate of C2 oxygenates would be enhanced. The advantage of using high temperature methanol catalyst PdZnAl in the combined catalyst system was demonstrated. In the presence of PdZnAl catalyst, the combined catalyst system was stable at temperature of 380oC. It was observed that, at high temperature, kinetics favored oxygenate formation. Results implied that the process can be intensified by operating at high temperature using Pd-based methanol synthesis catalyst. Steam reforming of the byproduct organics was demonstrated as a means to provide supplemental hydrogen. Preliminary process design, simulation, and economic analysis of the proposed CO2 conversion process were carried out. Economic analysis indicates how ethanol production cost was affected by the price of CO2 and hydrogen.

  15. Dedicated nuclear facilities for electrolytic hydrogen production

    Science.gov (United States)

    Foh, S. E.; Escher, W. J. D.; Donakowski, T. D.

    1979-01-01

    An advanced technology, fully dedicated nuclear-electrolytic hydrogen production facility is presented. This plant will produce hydrogen and oxygen only and no electrical power will be generated for off-plant use. The conceptual design was based on hydrogen production to fill a pipeline at 1000 psi and a 3000 MW nuclear base, and the base-line facility nuclear-to-shaftpower and shaftpower-to-electricity subsystems, the water treatment subsystem, electricity-to-hydrogen subsystem, hydrogen compression, efficiency, and hydrogen production cost are discussed. The final conceptual design integrates a 3000 MWth high-temperature gas-cooled reactor operating at 980 C helium reactor-out temperature, direct dc electricity generation via acyclic generators, and high-current density, high-pressure electrolyzers based on the solid polymer electrolyte approach. All subsystems are close-coupled and optimally interfaced and pipeline hydrogen is produced at 1000 psi. Hydrogen costs were about half of the conventional nuclear electrolysis process.

  16. Development of catalytic systems for selective hydrogenation and hydrogenolysis based on statistical planning methods coupled with kinetic studies

    Energy Technology Data Exchange (ETDEWEB)

    Zhorov, Yu.M.; Morozova, E.V.; Panchenkov, G.M.

    1979-01-01

    An efficient catalyst design methodology is described, which was used in developing an active and stable mixed oxide catalytic composition for selective hydrogenation of m-bonds under conditions excluding hydrogenolysis of C-C bonds. Catalysts of optimum composition, i.e., 40-50Vertical Bar3< CuO/25-30Vertical Bar3< NiO/20-35Vertical Bar3< SiO/sub 2/, and structure (20-30 A. average pore radius) can be prepared by coprecipitation of copper and nickel salts with silica gel powder in a sodium silicate solution at 90/sup 0/C. By using these catalysts, crotonaldehyde (CA) was hydrogenated to n-butanol in one stage with over 99Vertical Bar3< yields at 180/sup 0/C. The same catalyst was efficient in selective hydrogenation of acetylene (contained in relatively high concentrations in pyrolysis gases) to ethylene at 130/sup 0/C, hydrogenation of piperylene (a by-product in isoprene manufacture) to n-pentenes at 160/sup 0/C, with almost 100Vertical Bar3< selectivity, and in hydrogenolysis of C-S and C-N bonds at 290/sup 0/-370/sup 0/C. Catalytic hydrorefining of a gasoline fraction (105/sup 0/-180/sup 0/C bp) at 350/sup 0/C and 40 atm, reduced its sulfur content from 0.03Vertical Bar3< to 0.00001Vertical Bar3<, and completely removed nitrogen.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-08-01

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

  18. Research Progress in Production of Fuel Ethanol via Catalytic Hydrogenation of Methyl Acetate%醋酸甲酯催化加氢制备燃料乙醇的研究进展

    Institute of Scientific and Technical Information of China (English)

    管鑫; 曹祖宾; 韩冬云; 杨天宇; 宫建远

    2015-01-01

    As an essential factor in worldwide development, resources and energy are faced with a situation that they are strained and on the verge of exhaustion. In particular, petroleum supply, which supports the global financial development, is up against severe challenges. As a kind of new, recoverable substitution, fuel ethanol can be utilized as liquid fuel directly, or it can be used by mixing with gasoline so that the dependence on unrecoverable petroleum can be reduced. In the thesis, research progress in catalytic hydrogenation of methyl acetate to ethanol was summarized, moreover relevant processes and the selection of catalysts were discussed and analyzed.%作为世界各国发展中的必须因素,宝贵的能源面临着一度紧张和濒临枯竭的局面,特别是用以支撑全球经济发展的石油资源的供给正面临严峻挑战。燃料乙醇作为一种新型可再生燃料替代品,可直接用作液体燃料或者同燃料汽油混合使用,以减少对不可再生的石油资源的依赖。针对醋酸甲酯催化加氢的研究进展进行了综述,并且针对乙醇生产工艺及催化剂的选择问题作了讨论和分析。

  19. Fermentative hydrogen production by diverse microflora

    International Nuclear Information System (INIS)

    'Full text': In this study of hydrogen production with activated sludge, a diverse bacterial source has been investigated and compared to microflora from anaerobic digester sludge, which is less diverse. Batch experiments were conducted at mesophilic (37 oC) and thermophilic (55 oC) temperatures. The hydrogen production yields with activated sludge at 37 oC and 55 oC were 0.25 and 0.93 mol H2/mol glucose, respectively. The maximum hydrogen production rates with activated sludge in both temperatures were 4.2 mL/h. Anaerobic digester sludge showed higher hydrogen production yields and rates at both mesophilic and thermophilic temperatures. The results of repeated batch experiments with activated sludge showed an increase in the hydrogen production during the consecutive batches. However, hydrogen production was not stable along the repeated batches. The observed instability was due to the formation of lactic acid and ethanol. (author)

  20. Hydrogen production from microbial strains

    Science.gov (United States)

    Harwood, Caroline S; Rey, Federico E

    2012-09-18

    The present invention is directed to a method of screening microbe strains capable of generating hydrogen. This method involves inoculating one or more microbes in a sample containing cell culture medium to form an inoculated culture medium. The inoculated culture medium is then incubated under hydrogen producing conditions. Once incubating causes the inoculated culture medium to produce hydrogen, microbes in the culture medium are identified as candidate microbe strains capable of generating hydrogen. Methods of producing hydrogen using one or more of the microbial strains identified as well as the hydrogen producing strains themselves are also disclosed.

  1. Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

    International Nuclear Information System (INIS)

    High value-added aromatic aldehydes (e. g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide (H2O2) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin (Co(TPPS4)) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without Co(TPPS4). Moreover, a possible mechanism of HFBO oxidation using Co(TPPS4)/H2O2 was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under Co(TPPS4)/H2O2 system

  2. Photosynthetic production of hydrogen by algae

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H.

    1978-09-01

    Because hydrogen as a fuel is very attractive both in energy and ecological terms, the photosynthetic production of hydrogen by some algae is attracting considerable attention. In addition to the ordinary photosynthetic mechanisms, many algae have enzymes which can produce hydrogen: hydrogenation enzymes and nitrogen-fixation enzymes. Certain enzymes with the former begin to produce hydrogen after several hours in an anaerobic envirionment; the reason for the delay is that the hydrogen-producing enzymes must adjust to the anaerobic conditions. Eventually the production of hydrogen ceases because production of oxygen by the ordinary photosynthetic mechanism suppresses activity of the hydrogen-producing enzymes. Any use of these algae to produce hydrogen must involve alternating hydrogen production and rest. Nitrogen-fixing enzymes are found especially in the blue-green algae. These seem to produce hydrogen from organic compounds produced by the ordinary photosynthetic process. The nitrogen-fixation type of hydrogen-producing photosynthesis seems the more promising type for future exploitation.

  3. Molecular catalytic hydrogenation of aromatic hydrocarbons and hydrotreating of coal liquids.

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shiyong; Stock, L.M.

    1996-05-01

    This report presents the results of research on the development of new catalytic pathways for the hydrogenation of multiring aromatic hydrocarbons and the hydrotreating of coal liquids at The University of Chicago under DOE Contract No. DE-AC22-91PC91056. The work, which is described in three parts, is primarily concerned with the research on the development of new catalytic systems for the hydrogenation of aromatic hydrocarbons and for the improvement of the quality of coal liquids by the addition of dihydrogen. Part A discusses the activation of dihydrogen by very basic molecular reagents to form adducts that can facilitate the reduction of multiring aromatic hydrocarbons. Part B examines the hydrotreating of coal liquids catalyzed by the same base-activated dihydrogen complexes. Part C concerns studies of molecular organometallic catalysts for the hydrogenation of monocyclic aromatic hydrocarbons under mild conditions.

  4. Selective catalytic reduction of nitrogen oxides from industrial gases by hydrogen or methane

    International Nuclear Information System (INIS)

    This work deals with the selective catalytic reduction of nitrogen oxides (NOx), contained in the effluents of industrial plants, by hydrogen or methane. The aim is to replace ammonia, used as reducing agent, in the conventional process. The use of others reducing agents such as hydrogen or methane is interesting for different reasons: practical, economical and ecological. The catalyst has to convert selectively NO into N2, in presence of an excess of oxygen, steam and sulfur dioxide. The developed catalyst is constituted by a support such as perovskites, particularly LaCoO3, on which are dispersed noble metals (palladium, platinum). The interaction between the noble metal and the support, generated during the activation of the catalyst, allows to minimize the water and sulfur dioxide inhibitor phenomena on the catalytic performances, particularly in the reduction of NO by hydrogen. (O.M.)

  5. Biofuel production from catalytic cracking of woody oils.

    Science.gov (United States)

    Xu, Junming; Jiang, Jianchun; Chen, Jie; Sun, Yunjuan

    2010-07-01

    The catalytic cracking reactions of several kinds of woody oils have been studied. The products were analyzed by GC-MS and FTIR and show the formation of olefins, paraffins and carboxylic acids. Several kinds of catalysts were compared. It was found that the fraction distribution of product was modified by using base catalysts such as CaO. The products from woody oils showed good cold flow properties compared with diesel used in China. The results presented in this work have shown that the catalytic cracking of woody oils generates fuels that have physical and chemical properties comparable to those specified for petroleum based fuels. PMID:20206508

  6. Stereo-Specific Hydrogen Exchange Accompanying Catalytic Hydrogenation of Methyl β, β-Dimethylacrylate

    International Nuclear Information System (INIS)

    During platinum or palladium-catalysed hydrogenation in which, in solution, methyl β, β-dimethylacrylate is converted into the corresponding ester of isovaleric acid by the equation CH3CH3>C = CH-COOCH3 H2, cat. sol. --> CH3CH3>C = CH-CH2-COOCH3' an isotopic exchange of hydrogen between the gas and the solvent on the one hand and the substrate on the other is superposed upon the process of saturation of the double bond. This was studied by carrying out, at 20°C, hydrogenations which were interrupted after saturation of half the starting product and by employing D2 or esters deuterated either totally or at specific positions, different positions being used from experiment to experiment. The isotopic composition of the hydrogen at each of the positions of the molecules, both saturated and non-saturated, was determined, after separation of the molecules by chromatography in the gaseous phase, by combined mass spectrometry and nuclear magnetic resonance. A separate study was made of behaviour in respect of exchange of substrate in the non-saturated and saturated state, in the absence of hydrogen or the catalyst or both. Among the factors examined were, in particular, the effects of the solvent and the catalyst - which were very pronounced - on all the phenomena observed. These can be summarized as follows, (a) Molecules of the substrate no longer exchange once they are saturated, (b) With non-saturated molecules, restricted exchange takes place in which only the β-methyls are involved. This exchange is symmetric in the presence of rhodium and palladium, and stereo-specific in the presence of platinum - on an average 2.2 times greater in the cis-group than in the trans-group. This fact in the latter case excludes the hypothesis of double bond migration from the α-β position to the β-γ position as an exchange mechanism; which is confirmed by the absence of exchange at the exposition, (c) All the isotopic varieties from -d0 to -d6 or -d8 are present in the

  7. Fermentative hydrogen production by diverse microflora

    Energy Technology Data Exchange (ETDEWEB)

    Baghchehsaraee, B.; Nakhla, G.; Karamanev, D.; Margaritis, A. [Western Ontario Univ., London, ON (Canada). Dept. of Chemical and Biochemical Engineering

    2009-07-01

    This paper presented the results of a study in which hydrogen was produced from activated sludge. This diverse bacterial source has been compared to microflora from anaerobic digester sludge. Batch experiments were conducted at mesophilic (37 degrees C) and thermophilic (55 degrees C) temperatures. The hydrogen production yields with activated sludge at mesophilic and thermophilic temperatures were 0.25 and 0.93 mol H{sub 2}/mol glucose, respectively. The maximum hydrogen production rates with activated sludge in both temperatures were 4.2 mL/h. Anaerobic digester sludge showed higher hydrogen production yields and rates at both mesophilic and thermophilic temperatures. Repeated batch experiments with activated sludge resulted in increased hydrogen production in consecutive batches. However, the formation of lactic acid and ethanol resulted in unstable hydrogen production in the repeated batches.

  8. HTTR workshop (workshop on hydrogen production technology)

    International Nuclear Information System (INIS)

    Various research and development efforts have been performed to solve the global energy and environmental problems caused by large consumption of fossil fuels. Research activities on advanced hydrogen production technology by the use of nuclear heat from high temperature gas cooled reactors, for example, have been flourished in universities, research institutes and companies in many countries. The Department of HTTR Project and the Department of Advanced Nuclear Heat Technology of JAERI held the HTTR Workshop (Workshop on Hydrogen Production Technology) on July 5 and 6, 2004 to grasp the present status of R and D about the technology of HTGR and the nuclear hydrogen production in the world and to discuss about necessity of the nuclear hydrogen production and technical problems for the future development of the technology. More than 110 participants attended the Workshop including foreign participants from USA, France, Korea, Germany, Canada and United Kingdom. In the Workshop, the presentations were made on such topics as R and D programs for nuclear energy and hydrogen production technologies by thermo-chemical or other processes. Also, the possibility of the nuclear hydrogen production in the future society was discussed. The workshop showed that the R and D for the hydrogen production by the thermo-chemical process has been performed in many countries. The workshop affirmed that nuclear hydrogen production could be one of the competitive supplier of hydrogen in the future. The second HTTR Workshop will be held in the autumn next year. (author)

  9. Hydrogen Recombination Rates of Plate-type Passive Auto-catalytic Recombiner

    International Nuclear Information System (INIS)

    The hydrogen mitigation system may include igniters, passive autocatalytic recombiner (PAR), and venting or dilution system. Recently PAR is commonly used as a main component of HMS in a NPP containment because of its passive nature. PARs are categorized by the shape and material of catalytic surface. Catalytic surface coated by platinum is mostly used for the hydrogen recombiners. The shapes of the catalytic surface can be grouped into plate type, honeycomb type and porous media type. Among them, the plate-type PAR is well tested by many experiments. PAR performance analysis can be approached by a multi-scale method which is composed of micro, meso and macro scales. The criterion of the scaling is the ratio of thickness of boundary layer developed on a catalytic surface to representative length of a computational domain. Mass diffusion in the boundary layer must be resolved in the micro scale analysis. In a lumped parameter (LP) analysis using a system code such as MAAP or MELCOR, the chamber of the PAR is much smaller than a computational node. The hydrogen depletion by a PAR is modeled as a source of mass and energy conservation equations. Te catalytic surface reaction of hydrogen must be modeled by a volume-averaged correlation. In this study, a micro scale analysis method is developed using libraries in OpenFOAM to evaluate a hydrogen depletion rate depending on parameters such as size and number of plates and plate arrangement. The analysis code is validated by simulating REKO-3 experiment. And hydrogen depletion analysis is conducted by changing the plate arrangement as a trial of the performance enhancement of a PAR. In this study, a numerical code for an analysis of a PAR performance in a micro scale has been developed by using OpenFOAM libraries. The physical and numerical models were validated by simulating the REKO-3 experiment. As a try to enhance the performance of the plate-type PAR, it was proposed to apply a staggered two-layer arrangement of the

  10. Hydrogen Recombination Rates of Plate-type Passive Auto-catalytic Recombiner

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongtae; Hong, Seong-Wan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Gun Hong [Kyungwon E-C Co., Seongnam (Korea, Republic of)

    2014-10-15

    The hydrogen mitigation system may include igniters, passive autocatalytic recombiner (PAR), and venting or dilution system. Recently PAR is commonly used as a main component of HMS in a NPP containment because of its passive nature. PARs are categorized by the shape and material of catalytic surface. Catalytic surface coated by platinum is mostly used for the hydrogen recombiners. The shapes of the catalytic surface can be grouped into plate type, honeycomb type and porous media type. Among them, the plate-type PAR is well tested by many experiments. PAR performance analysis can be approached by a multi-scale method which is composed of micro, meso and macro scales. The criterion of the scaling is the ratio of thickness of boundary layer developed on a catalytic surface to representative length of a computational domain. Mass diffusion in the boundary layer must be resolved in the micro scale analysis. In a lumped parameter (LP) analysis using a system code such as MAAP or MELCOR, the chamber of the PAR is much smaller than a computational node. The hydrogen depletion by a PAR is modeled as a source of mass and energy conservation equations. Te catalytic surface reaction of hydrogen must be modeled by a volume-averaged correlation. In this study, a micro scale analysis method is developed using libraries in OpenFOAM to evaluate a hydrogen depletion rate depending on parameters such as size and number of plates and plate arrangement. The analysis code is validated by simulating REKO-3 experiment. And hydrogen depletion analysis is conducted by changing the plate arrangement as a trial of the performance enhancement of a PAR. In this study, a numerical code for an analysis of a PAR performance in a micro scale has been developed by using OpenFOAM libraries. The physical and numerical models were validated by simulating the REKO-3 experiment. As a try to enhance the performance of the plate-type PAR, it was proposed to apply a staggered two-layer arrangement of the

  11. Petroleum Refinery Hydrogen Production Unit: Exergy and Production Cost Evaluation

    Directory of Open Access Journals (Sweden)

    Silvio de Oliveira Júnior

    2008-12-01

    Full Text Available Some specific processes are required to obtain pure hydrogen and the most usual one is natural gas reforming, where natural gas reacts with superheated steam producing H2, CO, CO2 and H2O. This paper presents the exergy and production costs evaluation of a complete hydrogen production unit of a petroleum refinery. The hydrogen production unit analysed in this paper has to supply 550,000 Nm3 of hydrogen per day to purify diesel oil. Based on a synthesis plant of the hydrogen production unit, the exergy efficiency of each component and of the overall plant are calculated. The hydrogen production cost is determined by means of a thermoeconomic analysis in which the equality cost partition method is employed, including capital and operational costs, in order to determine the production cost of hydrogen and other products of the plant.

  12. Cellular graphene aerogel combines ultralow weight and high mechanical strength: A highly efficient reactor for catalytic hydrogenation.

    Science.gov (United States)

    Zhang, Bingxing; Zhang, Jianling; Sang, Xinxin; Liu, Chengcheng; Luo, Tian; Peng, Li; Han, Buxing; Tan, Xiuniang; Ma, Xue; Wang, Dong; Zhao, Ning

    2016-05-12

    The construction of three-dimensional graphene aerogels (GAs) is of great importance owing to their outstanding properties for various applications. Up to now, the combination of ultralow weight and super mechanical strength for GA remains a great challenge. Here we demonstrate the fabrication of cellular GAs by a facile, easily controlled and versatile route, i.e. the chemical reduction of graphene oxide assemblies at oil-water interface under a mild condition (70 °C). The GA is ultralight (with density <3 mg cm(-3)) yet mechanically resilient because the walls of the cell closely pack in a highly ordered manner to maximize mechanical strength. The GA has been utilized as an appealing reactor for catalytic hydrogenation, which exhibited great advantages such as large oil absorption capability, exceptional catalytic activity, ease of product separation and high stability.

  13. Cellular graphene aerogel combines ultralow weight and high mechanical strength: A highly efficient reactor for catalytic hydrogenation

    Science.gov (United States)

    Zhang, Bingxing; Zhang, Jianling; Sang, Xinxin; Liu, Chengcheng; Luo, Tian; Peng, Li; Han, Buxing; Tan, Xiuniang; Ma, Xue; Wang, Dong; Zhao, Ning

    2016-05-01

    The construction of three-dimensional graphene aerogels (GAs) is of great importance owing to their outstanding properties for various applications. Up to now, the combination of ultralow weight and super mechanical strength for GA remains a great challenge. Here we demonstrate the fabrication of cellular GAs by a facile, easily controlled and versatile route, i.e. the chemical reduction of graphene oxide assemblies at oil-water interface under a mild condition (70 °C). The GA is ultralight (with density resilient because the walls of the cell closely pack in a highly ordered manner to maximize mechanical strength. The GA has been utilized as an appealing reactor for catalytic hydrogenation, which exhibited great advantages such as large oil absorption capability, exceptional catalytic activity, ease of product separation and high stability.

  14. Cellular graphene aerogel combines ultralow weight and high mechanical strength: A highly efficient reactor for catalytic hydrogenation.

    Science.gov (United States)

    Zhang, Bingxing; Zhang, Jianling; Sang, Xinxin; Liu, Chengcheng; Luo, Tian; Peng, Li; Han, Buxing; Tan, Xiuniang; Ma, Xue; Wang, Dong; Zhao, Ning

    2016-01-01

    The construction of three-dimensional graphene aerogels (GAs) is of great importance owing to their outstanding properties for various applications. Up to now, the combination of ultralow weight and super mechanical strength for GA remains a great challenge. Here we demonstrate the fabrication of cellular GAs by a facile, easily controlled and versatile route, i.e. the chemical reduction of graphene oxide assemblies at oil-water interface under a mild condition (70 °C). The GA is ultralight (with density <3 mg cm(-3)) yet mechanically resilient because the walls of the cell closely pack in a highly ordered manner to maximize mechanical strength. The GA has been utilized as an appealing reactor for catalytic hydrogenation, which exhibited great advantages such as large oil absorption capability, exceptional catalytic activity, ease of product separation and high stability. PMID:27174450

  15. CATALYTIC BEHAVIOR OF A SILICA-SUPPORTED POLYTITAZANE-PLATINUM COMPLEX FOR THE HYDROGENATION OF PHENOL

    Institute of Scientific and Technical Information of China (English)

    CHEN Chunwei; HUANG Meiyu; JIANG Yingyan

    1996-01-01

    A new kind of inorganic polymer, viz. silica-supported polytitazane (Ti-N), and its platinum complex (Ti-N-Pt) were prepared. Cyclohexanone can be obtained in a maximum yield of about 62.2% in the hydrogenation of phenol over Ti-N-Pt at room temperature under atmospheric pressure. The effects of mole ratio of N/Pt in the complex, concentration of the catalyst and reaction temperature on the catalytic activity and selectivity have been studied. The complex can be reused several times without loss in its catalytic activity.

  16. Catalytic partial oxidation coupled with membrane purification to improve resource and energy efficiency in syngas production.

    Science.gov (United States)

    Iaquaniello, G; Salladini, A; Palo, E; Centi, G

    2015-02-01

    Catalytic partial oxidation coupled with membrane purification is a new process scheme to improve resource and energy efficiency in a well-established and large scale-process like syngas production. Experimentation in a semi industrial-scale unit (20 Nm(3)  h(-1) production) shows that a novel syngas production scheme based on a pre-reforming stage followed by a membrane for hydrogen separation, a catalytic partial oxidation step, and a further step of syngas purification by membrane allows the oxygen-to-carbon ratio to be decreased while maintaining levels of feed conversion. For a total feed conversion of 40 %, for example, the integrated novel architecture reduces oxygen consumption by over 50 %, with thus a corresponding improvement in resource efficiency and an improved energy efficiency and economics, these factors largely depending on the air separation stage used to produce pure oxygen. PMID:25571881

  17. Redirection of metabolism for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Harwood, Caroline S.

    2011-11-28

    This project is to develop and apply techniques in metabolic engineering to improve the biocatalytic potential of the bacterium Rhodopseudomonas palustris for nitrogenase-catalyzed hydrogen gas production. R. palustris, is an ideal platform to develop as a biocatalyst for hydrogen gas production because it is an extremely versatile microbe that produces copious amounts of hydrogen by drawing on abundant natural resources of sunlight and biomass. Anoxygenic photosynthetic bacteria, such as R. palustris, generate hydrogen and ammonia during a process known as biological nitrogen fixation. This reaction is catalyzed by the enzyme nitrogenase and normally consumes nitrogen gas, ATP and electrons. The applied use of nitrogenase for hydrogen production is attractive because hydrogen is an obligatory product of this enzyme and is formed as the only product when nitrogen gas is not supplied. Our challenge is to understand the systems biology of R. palustris sufficiently well to be able to engineer cells to produce hydrogen continuously, as fast as possible and with as high a conversion efficiency as possible of light and electron donating substrates. For many experiments we started with a strain of R. palustris that produces hydrogen constitutively under all growth conditions. We then identified metabolic pathways and enzymes important for removal of electrons from electron-donating organic compounds and for their delivery to nitrogenase in whole R. palustris cells. For this we developed and applied improved techniques in 13C metabolic flux analysis. We identified reactions that are important for generating electrons for nitrogenase and that are yield-limiting for hydrogen production. We then increased hydrogen production by blocking alternative electron-utilizing metabolic pathways by mutagenesis. In addition we found that use of non-growing cells as biocatalysts for hydrogen gas production is an attractive option, because cells divert all resources away from growth and

  18. Hydrogen production by recombinant Escherichia coli strains

    OpenAIRE

    Maeda, Toshinari; Sanchez‐Torres, Viviana; Thomas K Wood

    2012-01-01

    Summary The production of hydrogen via microbial biotechnology is an active field of research. Given its ease of manipulation, the best‐studied bacterium Escherichia coli has become a workhorse for enhanced hydrogen production through metabolic engineering, heterologous gene expression, adaptive evolution, and protein engineering. Herein, the utility of E. coli strains to produce hydrogen, via native hydrogenases or heterologous ones, is reviewed. In addition, potential strategies for increas...

  19. Selective Catalytic Synthesis Using the Combination of Carbon Dioxide and Hydrogen: Catalytic Chess at the Interface of Energy and Chemistry.

    Science.gov (United States)

    Klankermayer, Jürgen; Wesselbaum, Sebastian; Beydoun, Kassem; Leitner, Walter

    2016-06-20

    The present Review highlights the challenges and opportunities when using the combination CO2 /H2 as a C1 synthon in catalytic reactions and processes. The transformations are classified according to the reduction level and the bond-forming processes, covering the value chain from high volume basic chemicals to complex molecules, including biologically active substances. Whereas some of these concepts can facilitate the transition of the energy system by harvesting renewable energy into chemical products, others provide options to reduce the environmental impact of chemical production already in today's petrochemical-based industry. Interdisciplinary fundamental research from chemists and chemical engineers can make important contributions to sustainable development at the interface of the energetic and chemical value chain. The present Review invites the reader to enjoy this exciting area of "catalytic chess" and maybe even to start playing some games in her or his laboratory. PMID:27237963

  20. Hydrogen Production by Catalytic Partial Oxidation of Coke Oven Gas in BaCo0.7Fe0.3-xZrxO3-δ Ceramic Membrane Reactors

    Directory of Open Access Journals (Sweden)

    Yao Weilin

    2016-01-01

    Full Text Available The BaCo0.7Fe0.3-xZrxO3-δ (BCFZ, x = 0.04–0.12 mixed ionic–electronic conducting (MIEC membranes were synthesized with a sol–gel method and evaluated as potential membrane reactor materials for the partial oxidation of coke oven gas (COG. The effect of zirconium content on the phase structure, microstructure and performance of the BCFZ membrane under He or COG atmosphere were systemically investigated. The BaCo0.7Fe0.24Zr0.06O3-δ membrane exhibited the best oxygen permeability and good operation stability, which could be a potential candidate of the membrane materials for hydrogen production through the partial oxidation of COG.

  1. Biomass to hydrogen via fast pyrolysis and catalytic steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Chornet, E.; Wang, D.; Montane, D. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1995-09-01

    Fast pyrolysis of biomass results in a pyrolytic oil which is a mixture of (a) carbohydrate-derived acids, aldehydes and polyols, (b) lignin-derived substituted phenolics, and (c) extractives-derived terpenoids and fatty acids. The conversion of this pyrolysis oil into H{sub 2} and CO{sub 2} is thermodynamically favored under appropriate steam reforming conditions. Our efforts have focused in understanding the catalysis of steam reforming which will lead to a successful process at reasonable steam/carbon ratios arid process severities. The experimental work, carried out at the laboratory and bench scale levels, has centered on the performance of Ni-based catalysts using model compounds as prototypes of the oxygenates present in the pyrolysis oil. Steam reforming of acetic acid, hydroxyacetaldehyde, furfural and syringol has been proven to proceed rapidly within a reasonable range of severities. Time-on-stream studies are now underway using a fixed bed barometric pressure reactor to ascertain the durability of the catalysts and thus substantiate the scientific and technical feasibility of the catalytic reforming option. Economic analyses are being carried out in parallel to determine the opportunity zones for the combined fast pyrolysis/steam reforming approach. A discussion on the current state of the project is presented.

  2. Hydrogen Production by Water Biophotolysis

    Energy Technology Data Exchange (ETDEWEB)

    Ghirardi, Maria L.; King, Paul W.; Mulder, David W.; Eckert, Carrie; Dubini, Alexandra; Maness, Pin-Ching; Yu, Jianping

    2014-01-22

    The use of microalgae for production of hydrogen gas from water photolysis has been studied for many years, but its commercialization is still limited by multiple challenges. Most of the barriers to commercialization are attributed to the existence of biological regulatory mechanisms that, under anaerobic conditions, quench the absorbed light energy, down-regulate linear electron transfer, inactivate the H2-producing enzyme, and compete for electrons with the hydrogenase. Consequently, the conversion efficiency of absorbed photons into H2 is significantly lower than its estimated potential of 12–13 %. However, extensive research continues towards addressing these barriers by either trying to understand and circumvent intracellular regulatory mechanisms at the enzyme and metabolic level or by developing biological systems that achieve prolonged H2 production albeit under lower than 12–13 % solar conversion efficiency. This chapter describes the metabolic pathways involved in biological H2 photoproduction from water photolysis, the attributes of the two hydrogenases, [FeFe] and [NiFe], that catalyze biological H2 production, and highlights research related to addressing the barriers described above. These highlights include: (a) recent advances in improving our understanding of the O2 inactivation mechanism in different classes of hydrogenases; (b) progress made in preventing competitive pathways from diverting electrons from H2 photoproduction; and (c) new developments in bypassing the non-dissipated proton gradient from down-regulating photosynthetic electron transfer. As an example of a major success story, we mention the generation of truncated-antenna mutants in Chlamydomonas and Synechocystis that address the inherent low-light saturation of photosynthesis. In addition, we highlight the rationale and progress towards coupling biological hydrogenases to non-biological, photochemical charge-separation as a means to bypass the barriers of photobiological

  3. Nuclear energy for sustainable Hydrogen production

    International Nuclear Information System (INIS)

    There is general agreement that hydrogen as an universal energy carrier could play increasingly important role in energy future as part of a set of solutions to a variety of energy and environmental problems. Given its abundant nature, hydrogen has been an important raw material in the organic chemical industry. At recent years strong competition has emerged between nations as diverse as the U.S., Japan, Germany, China and Iceland in the race to commercialize hydrogen energy vehicles in the beginning of 21st Century. Any form of energy - fossil, renewable or nuclear - can be used to generate hydrogen. The hydrogen production by nuclear electricity is considered as a sustainable method. By our presentation we are trying to evaluate possibilities for sustainable hydrogen production by nuclear energy at near, medium and long term on EC strategic documents basis. The main EC documents enter water electrolysis by nuclear electricity as only sustainable technology for hydrogen production in early stage of hydrogen economy. In long term as sustainable method is considered the splitting of water by thermochemical technology using heat from high temperature reactors too. We consider that at medium stage of hydrogen economy it is possible to optimize the sustainable hydrogen production by high temperature and high pressure water electrolysis by using a nuclear-solar energy system. (author)

  4. Hydrogen. Production and application in industry

    Energy Technology Data Exchange (ETDEWEB)

    Dueker, A. [Sued-Chemie AG, Muenchen (Germany)

    2010-12-30

    Hydrogen is one of the most fascinating elements in Universe. Its unique properties made it to a matter that is used in a wide range of different industrial applications. Besides the chemical role of Hydrogen as a hydrogenation agent, it will play an ever more important role in the global energy house hold. This presentation focuses on the classical technologies for the production of Hydrogen based on a variety of raw materials and will show the most important applications of Hydrogen in large scale industry. (orig.)

  5. Catalytic Hydrolysis of Ammonia Borane by Cobalt Nickel Nanoparticles Supported on Reduced Graphene Oxide for Hydrogen Generation

    Directory of Open Access Journals (Sweden)

    Yuwen Yang

    2014-01-01

    Full Text Available Well dispersed magnetically recyclable bimetallic CoNi nanoparticles (NPs supported on the reduced graphene oxide (RGO were synthesized by one-step in situ coreduction of aqueous solution of cobalt(II chloride, nickel (II chloride, and graphite oxide (GO with ammonia borane (AB as the reducing agent under ambient condition. The CoNi/RGO NPs exhibits excellent catalytic activity with a total turnover frequency (TOF value of 19.54 mol H2 mol catalyst−1 min−1 and a low activation energy value of 39.89 kJ mol−1 at room temperature. Additionally, the RGO supported CoNi NPs exhibit much higher catalytic activity than the monometallic and RGO-free CoNi counterparts. Moreover, the as-prepared catalysts exert satisfying durable stability and magnetically recyclability for the hydrolytic dehydrogenation of AB, which make the practical reusing application of the catalysts more convenient. The usage of the low-cost, easy-getting catalyst to realize the production of hydrogen under mild condition gives more confidence for the application of ammonia borane as a hydrogen storage material. Hence, this general method indicates that AB can be used as both a potential hydrogen storage material and an efficient reducing agent, and can be easily extended to facile preparation of other RGO-based metallic systems.

  6. Hydrogen production through biocatalyzed electrolysis

    NARCIS (Netherlands)

    Rozendal, R.A.

    2007-01-01

    cum laude graduation (with distinction) To replace fossil fuels, society is currently considering alternative clean fuels for transportation. Hydrogen could be such a fuel. In theory, large amounts of renewable hydrogen can be produced from organic contaminants in wastewater. During his PhD research

  7. Scenarios of hydrogen production from wind power

    Energy Technology Data Exchange (ETDEWEB)

    Klaric, Mario

    2010-09-15

    Since almost total amount of hydrogen is currently being produced from natural gas, other ways of cleaner and 'more renewable' production should be made feasible in order to make benchmarks for total 'hydrogen economy'. Hydrogen production from wind power combined with electrolysis imposes as one possible framework for new economy development. In this paper various wind-to-hydrogen scenarios were calculated. Cash flows of asset based project financing were used as decision making tool. Most important parameters were identified and strategies for further research and development and resource allocation are suggested.

  8. Research of Hydrogen Preparation with Catalytic Steam-Carbon Reaction Driven by Photo-Thermochemistry Process

    Directory of Open Access Journals (Sweden)

    Xiaoqing Zhang

    2013-01-01

    Full Text Available An experiment of hydrogen preparation from steam-carbon reaction catalyzed by K2CO3 was carried out at 700°C, which was driven by the solar reaction system simulated with Xenon lamp. It can be found that the rate of reaction with catalyst is 10 times more than that without catalyst. However, for the catalytic reaction, there is no obvious change for the rate of hydrogen generation with catalyst content range from 10% to 20%. Besides, the conversion efficiency of solar energy to chemical energy is more than 13.1% over that by photovoltaic-electrolysis route. An analysis to the mechanism of catalytic steam-carbon reaction with K2CO3 is given, and an explanation to the nonbalanced [H2]/[CO + 2CO2] is presented, which is a phenomenon usually observed in experiment.

  9. Development programme on hydrogen production in HTTR

    International Nuclear Information System (INIS)

    In Japan Atomic Energy Research Institute, a hydrogen production system is being designed to produce hydrogen by means of a steam reforming process of natural gas using nuclear heat (10MW, 905 deg. C) supplied by the High Temperature Engineering Test Reactor (HTTR). The safety principle and criteria are also being investigated in the HTTR hydrogen production system. A facility for an out-of-pile test prior to the demonstration test with the HTTR hydrogen production system is under manufacture. The out-of-pile test facility simulates key components downstream an intermediate heat exchanger of the HTTR hydrogen production system on a scale of 1 to 30. The test on safety, controllability and performance of the hydrogen production system will be started in 2001 and continued for 4 years or longer. In parallel to this, a hydrogen permeation test and a corrosion test of a catalyst tube of a steam reformer are being carried out to obtain data necessary for the design of the system. As for the HTTR hydrogen production system, a conceptual design is in progress, and check and review for the demonstration program will be made in 2000 from a financial point of view as well as technical view. Following a brief overview of the program, the design achievements including safety philosophy so far and technical issues to be resolved are to be summarized in the paper. (author)

  10. A new process for preparing dialdehyde by catalytic oxidation of cyclic olefins with aqueous hydrogen peroxide

    Institute of Scientific and Technical Information of China (English)

    YU, Hong-Kun; PANG, Zhen; HUANG, Zu-En; CAI, Rui-Fang

    2000-01-01

    A novel peroxo-nioboplosphate was synthesized for the first time and used as a catalyst in the oxidation reaction of cyclic olefins with aqueous hydrogen peroxide to prepare dialdehydes. The catalyst was characterized by elemental analysis,thermographic analyses, IR, UV/vis, 31P NMR and XPS ~ as [ π-C5H5N(CH2)i3CH3 ]2 [Nb406 (O2)2 (PO4)2] ·6H20 (PTNP). It showed high selectivity to glutaraldehyde in the catalytic oxidation of cyclopentene with aqueous hydrogen peroxide in ethanol.

  11. Exploiting high pressure advantages in catalytic hydrogenation of carbon dioxide to methanol

    OpenAIRE

    Bansode, Atul Baban

    2014-01-01

    The aim of this thesis was to develop highly efficient CO2 hydrogenation process towards methanol by making use of high pressure approach. A high pressure lab scale plant was developed to conduct CO2 hydrogenation up to 400 bar. High pressure and low temperature were found to be the favourable conditions to excellent catalytic activity. Improved reaction performance towards methanol synthesis and reverse water-gas shift reaction was observed for the Ba and K promoted Cu/Al2O3 catalysts, respe...

  12. Catalytic abatement of nitrous oxide from nitric and production

    NARCIS (Netherlands)

    Oonk, J.

    1998-01-01

    Nitric acid production is identified as a main source of nitrous oxide. Options for emission reduction however are not available. TNO and Hydro Agri studied the technological and economic feasibility of catalytic decomposition of nitrous oxide in nitric acid tail-gases. Although in literature promis

  13. Catalytic Transfer Hydrogenation with a Methandiide-Based Carbene Complex: An Experimental and Computational Study.

    Science.gov (United States)

    Weismann, Julia; Gessner, Viktoria H

    2015-11-01

    The transfer hydrogenation (TH) reaction of ketones with catalytic systems based on a methandiide-derived ruthenium carbene complex was investigated and optimised. The complex itself makes use of the noninnocent behaviour of the carbene ligand (M=CR2 →MH-C(H)R2 ), but showed only moderate activity, thus requiring long reaction times to achieve sufficient conversion. DFT studies on the reaction mechanism revealed high reaction barriers for both the dehydrogenation of iPrOH and the hydrogen transfer. A considerable improvement of the catalytic activity could be achieved by employing triphenylphosphine as additive. Mechanistic studies on the role of PPh3 in the catalytic cycle revealed the formation of a cyclometalated complex upon phosphine coordination. This ruthenacycle was revealed to be the active species under the reaction conditions. The use of the isolated complex resulted in high catalytic activities in the TH of aromatic as well as aliphatic ketones. The complex was also found to be active under base-free conditions, suggesting that the cyclometalation is crucial for the enhanced activity. PMID:26403918

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

    Science.gov (United States)

    Chew, Thiam Leng; Bhatia, Subhash

    2008-11-01

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

  15. State of the art on hydrogen passive auto-catalytic recombiner (european union Parsoar project)

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, F.; Bachellerie, E. [Technicatome, 13 - Aix en Provence (France); Auglaire, M. [Tractebel Energy Engineering, Brussels (Belgium); Boeck, B. de [Association Vincotte Nuclear, Brussels (Belgium); Braillard, O. [CEA Cadarache, 13 - Saint Paul lez Durance (France); Eckardt, B. [Siemens AG, Offenbach am Main (Germany); Ferroni, F. [Electrowatt Engineering Limited, Zurich (Switzerland); Moffett, R. [Atomic Energy Canada Limited, Pinawa (Canada); Van Goethem, G. [European Commission, Brussels (Belgium)

    2001-07-01

    This paper presents an overview of the European Union PARSOAR project, which consists in carrying out a state of the art on hydrogen passive auto-catalytic recombiner (PAR) and a handbook guide for implementing these devices in nuclear power plants. This work is performed in the area ''Operational Safety of Existing Installations'' of the key action ''Nuclear Fission'' of the fifth Euratom Framework Programme (1998-2002). (author)

  16. Ruthenium on rutile catalyst, catalytic system, and method for aqueous phase hydrogenations

    Science.gov (United States)

    Elliot, Douglas C.; Werpy, Todd A.; Wang, Yong; Frye, Jr., John G.

    2001-01-01

    An essentially nickel- and rhenium-free catalyst is described comprising ruthenium on a titania support where the titania is greater than 75% rutile. A catalytic system containing a nickel-free catalyst comprising ruthenium on a titania support where the titania is greater than 75% rutile, and a method using this catalyst in the hydrogenation of an organic compound in the aqueous phase is also described.

  17. State of the art on hydrogen passive auto-catalytic recombiner (european union Parsoar project)

    International Nuclear Information System (INIS)

    This paper presents an overview of the European Union PARSOAR project, which consists in carrying out a state of the art on hydrogen passive auto-catalytic recombiner (PAR) and a handbook guide for implementing these devices in nuclear power plants. This work is performed in the area ''Operational Safety of Existing Installations'' of the key action ''Nuclear Fission'' of the fifth Euratom Framework Programme (1998-2002). (author)

  18. Liquid-Phase Catalytic Transfer Hydrogenation of Furfural over Homogeneous Lewis Acid-Ru/C Catalysts.

    Science.gov (United States)

    Panagiotopoulou, Paraskevi; Martin, Nickolas; Vlachos, Dionisios G

    2015-06-22

    The catalytic performance of homogeneous Lewis acid catalysts and their interaction with Ru/C catalyst are studied in the catalytic transfer hydrogenation of furfural by using 2-propanol as a solvent and hydrogen donor. We find that Lewis acid catalysts hydrogenate the furfural to furfuryl alcohol, which is then etherified with 2-propanol. The catalytic activity is correlated with an empirical scale of Lewis acid strength and exhibits a volcano behavior. Lanthanides are the most active, with DyCl3 giving complete furfural conversion and a 97 % yield of furfuryl alcohol at 180 °C after 3 h. The combination of Lewis acid and Ru/C catalysts results in synergy for the stronger Lewis acid catalysts, with a significant increase in the furfural conversion and methyl furan yield. Optimum results are obtained by using Ru/C combined with VCl3 , AlCl3 , SnCl4 , YbCl3 , and RuCl3 . Our results indicate that the combination of Lewis acid/metal catalysts is a general strategy for performing tandem reactions in the upgrade of furans.

  19. Visbreaking based integrated process for bitumen upgrading and hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Sosa, C.; Gonzalez, M.F.; Carbognani, L.; Perez-Zurita, M.J.; Lopez-Linares, F.; Husein, M.; Moore, G.; Pereira, P. [Calgary Univ., AB (Canada). Alberta In Situ Centre For In Situ Energy, Schulich School Of Engineering

    2006-07-01

    New and cost effective upgrading schemes for distillates production and residue disposal are needed in order to recover Alberta's vast heavy oil and bitumen reserves. On average, heavy oils and bitumen contain 50 per cent (w/w) of components remaining after vacuum distillation. A new alternative for upgrading vacuum resids was proposed. The method involves the following 3 processing steps: production of modified, nearly unstable heavy molecules by mild thermal cracking known as visbreaking; adsorption of modified heavy molecules over inexpensive, tailor-designed porous sorbents or catalysts; and, production of hydrogen by low temperature catalytic steam gasification of the adsorbed molecules. This cost effective way of producing hydrogen is based on the selective segregation of a minimal fraction of the heaviest hydrocarbon molecules, those most instable, followed by their gasification at low temperature. This paper presented results on the combined processing as well as using both a model molecule and real feedstock from the Athabasca vacuum resids for the adsorption and hydrogen production steps. The study showed that this new process can obtain high rates of hydrogen production when a kaolin based solid formulation is used as both, adsorbent and catalysts, for these heavy molecules. It was concluded that this alternative method for producing hydrogen at upgrading sites in northern Alberta has potential for both installed and future up-graders to improve the quality of synthetic crude being produced. The hydrogen produced from the gasification of these heavy compounds could be used for both refining purposes or for in-situ reservoir upgrading. 27 refs., 3 figs.

  20. Hydrogen production through biocatalyzed electrolysis

    OpenAIRE

    Rozendal, R.A.

    2007-01-01

    cum laude graduation (with distinction) To replace fossil fuels, society is currently considering alternative clean fuels for transportation. Hydrogen could be such a fuel. In theory, large amounts of renewable hydrogen can be produced from organic contaminants in wastewater. During his PhD research René Rozendal has developed a new technology for this purpose: biocatalyzed electrolysis. The innovative step of biocatalyzed electrolysis is the application of electrochemically active microorgan...

  1. Structural and textural properties of Fe2O3/γ-Al2O3 catalysts and their importance in the catalytic reforming of CH4 with H2S for hydrogen production

    Science.gov (United States)

    Galindo-Hernández, Félix; Domínguez, J. M.; Portales, Benjamín

    2015-08-01

    Newer catalysts for the methane reforming with H2S are designed, which are based on Fe2O3/γ-Al2O3, nanocrystalline γ-Al2O3 supports, and 1.0 to 6.0 wt% Fe. The main phases are identified as hematite and γ-Al2O3, with sizes of about 2-4 nm. The structural features are characterized by X-ray diffraction, Rietveld's Refinement and Radial Distribution Function analysis. The textural properties of these catalysts are determined by N2 sorption and surface fractal dimension calculations. Also, the electronic states are inferred by Mössbauer and UV-Vis (diffuse reflectance) spectroscopies. The activity of Fe2O3/γ-Al2O3 catalysts in the methane reforming is tested in a fixed bed type reactor. Further calculations indicate that Fe2O3/γ-Al2O3 catalysts go through a charge transfer decrease, which depends on the iron content, i.e., from 1.08 to 0.88 eV; Mössbauer spectroscopy reveals that Fe3+ ions adopt a tetrahedral coordination, which coincides with their higher activity for hydrogen production, with respect to catalysts having octahedral coordination. The specific surface area of these catalysts is about 84 m2 g-1, with a mean pore diameter of 2.5 nm. A mechanism for the methane reforming with H2S is proposed herein.

  2. Production of Hydrogen from Underground Coal Gasification

    Science.gov (United States)

    Upadhye, Ravindra S.

    2008-10-07

    A system of obtaining hydrogen from a coal seam by providing a production well that extends into the coal seam; positioning a conduit in the production well leaving an annulus between the conduit and the coal gasification production well, the conduit having a wall; closing the annulus at the lower end to seal it from the coal gasification cavity and the syngas; providing at least a portion of the wall with a bifunctional membrane that serves the dual purpose of providing a catalyzing reaction and selectively allowing hydrogen to pass through the wall and into the annulus; and producing the hydrogen through the annulus.

  3. Developments and constraints in fermentative hydrogen production

    NARCIS (Netherlands)

    Bartacek, J.; Zabranska, J.; Lens, P.N.L.

    2007-01-01

    Fermentative hydrogen production is a novel aspect of anaerobic digestion. The main advantage of hydrogen is that it is a clean and renewable energy source/carrier with high specific heat of combustion and no contribution to the Greenhouse effect, and can be used in many industrial applications. Thi

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

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D. C.

    2013-01-22

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

  5. Substrate-mediated enhanced activity of Ru nanoparticles in catalytic hydrogenation of benzene

    KAUST Repository

    Liu, Xin

    2012-01-01

    The impact of carbon substrate-Ru nanoparticle interactions on benzene and hydrogen adsorption that is directly related to the performance in catalytic hydrogenation of benzene has been investigated by first-principles based calculations. The stability of Ru 13 nanoparticles is enhanced by the defective graphene substrate due to the hybridization between the dsp states of the Ru 13 particle with the sp 2 dangling bonds at the defect sites. The local curvature formed at the interface will also raise the Ru atomic diffusion barrier, and prohibit the particle sintering. The strong interfacial interaction results in the shift of averaged d-band center of the deposited Ru nanoparticle, from -1.41 eV for a freestanding Ru 13 particle, to -1.17 eV for the Ru/Graphene composites, and to -1.54 eV on mesocellular foam carbon. Accordingly, the adsorption energies of benzene are increased from -2.53 eV for the Ru/mesocellular foam carbon composites, to -2.62 eV on freestanding Ru 13 particles, to -2.74 eV on Ru/graphene composites. A similar change in hydrogen adsorption is also observed, and all these can be correlated to the shift of the d-band center of the nanoparticle. Thus, Ru nanoparticles graphene composites are expected to exhibit both high stability and superior catalytic performance in hydrogenation of arenes. © 2012 The Royal Society of Chemistry.

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

    Science.gov (United States)

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

    2010-05-18

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

  7. Hydrogen production from biomass over steam gasification

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, R.; Potetz, A.; Hofbauer, H. [Vienna Univ. of Technology (Austria). Inst. of Chemical Engineering; Weber, G. [Bioenergy 2020+, Guessing (Austria)

    2010-12-30

    Renewable hydrogen is one option for a clean energy carrier in the future. There were several research programs in the past, to produce hydrogen on a renewable basis by electrolysis, direct conversion of water or by gasification of biomass. None of these options were developed to a stage, that they could be used on a commercial basis. At the moment almost all hydrogen is produced from fossil fuels and one main consumer of hydrogen are refineries. So a good option to demonstrate the production of renewable hydrogen and bring it later into the market is over refineries. The most economic option to produce renewable hydrogen at the moment is over gasification of biomass. In Austria an indirect gasification system was developed and is demonstrated in Guessing, Austria. The biomass CHP Guessing uses the allothermal steam dual fluidised bed gasifier and produces a high grade product gas, which is used at the moment for the CHP in a gas engine. As there is no nitrogen in the product gas and high hydrogen content, this gas can be also used as synthesis gas or for production of hydrogen. The main aim of this paper is to present the experimental and simulation work to convert biomass into renewable hydrogen. The product gas of the indirect gasification system is mainly hydrogen, carbon monoxide, carbon dioxide and methane. Within the ERA-Net project ''OptiBtLGas'' the reforming of methane and the CO-shift reaction was investigated to convert all hydrocarbons and carbon monoxide to hydrogen. On basis of the experimental results the mass- and energy balances of a commercial 100 MW fuel input plant was done. Here 3 different cases of complexity of the overall plant were simulated. The first case was without reforming and CO-shift, only by hydrogen separation. The second case was by including steam - reforming and afterwards separation of hydrogen. The third case includes hydrocarbon reforming, CO-shift and hydrogen separation. In all cases the off-gases (CO

  8. Fermentative hydrogen production at high sulfate concentration

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chin-Chao [Environmental Resources Laboratory, Department of Landscape Architecture, Chungchou Institute of Technology, Changhwa 51022 (China); Chen, Hong-Pin; Wu, Jou-Hsien; Lin, Chiu-Yue [BioHydrogen Laboratory, Department of Water Resource Engineering, Feng Chia University, P.O. Box 25-123, Taichung 40724 (China)

    2008-03-15

    The hydraulic retention time (HRT) effects on fermentative hydrogen production from sucrose at high sulfate concentration of 3 g-SO{sub 4}{sup 2-}/l were studied using enriched mixed-microflora in a continuously fed reactor. The tested HRTs and organic loading rate ranged from 10 to 2 h and 48 to 240 g-COD/l-day, respectively, and the operating pH was 5.5. The experimental results indicate that hydrogen production could not be inhibited under high sulfate concentration and the efficiency was HRT-dependent with a short HRT of 4 h efficiently enhanced hydrogen production. At this HRT the biogas production rate and hydrogen gas content peaked with the hydrogen yield, hydrogen production rate and specific hydrogen production rate of 4.70 mol-H{sub 2}/mol-sucrose, 874 mmol-H{sub 2}/l-day and 432 mmol-H{sub 2}/g-VSS-day, respectively. These values were 50%, 80% and 300%, respectively, higher than those reported for 12 h HRT at the same sulfate concentration. The metabolite concentration fractions were butyrate 77.3%, acetate 15.6%, ethanol 4.4% and propionate 2.0% and changed to 55%, 27.3%, 11.2% and 6.5%, respectively, at HRT 2 h. Therefore, intimate HRT control is important to obtain efficient hydrogen production. Based on a biological growth comparison, pH 5.5 was considered to be the optimal value for operating a hydrogen-producing fermenter fed on sulfate-rich substrate. (author)

  9. Thermocatalytic CO2-Free Production of Hydrogen from Hydrocarbon Fuels

    Energy Technology Data Exchange (ETDEWEB)

    University of Central Florida

    2004-01-30

    The main objective of this project is the development of an economically viable thermocatalytic process for production of hydrogen and carbon from natural gas or other hydrocarbon fuels with minimal environmental impact. The three major technical goals of this project are: (1) to accomplish efficient production of hydrogen and carbon via sustainable catalytic decomposition of methane or other hydrocarbons using inexpensive and durable carbon catalysts, (2) to obviate the concurrent production of CO/CO{sub 2} byproducts and drastically reduce CO{sub 2} emissions from the process, and (3) to produce valuable carbon products in order to reduce the cost of hydrogen production The important feature of the process is that the reaction is catalyzed by carbon particulates produced in the process, so no external catalyst is required (except for the start-up operation). This results in the following advantages: (1) no CO/CO{sub 2} byproducts are generated during hydrocarbon decomposition stage, (2) no expensive catalysts are used in the process, (3) several valuable forms of carbon can be produced in the process depending on the process conditions (e.g., turbostratic carbon, pyrolytic graphite, spherical carbon particles, carbon filaments etc.), and (4) CO{sub 2} emissions could be drastically reduced (compared to conventional processes).

  10. Production of hydrogen by superadiabatic decomposition of hydrogen sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Slimane, R.B.; Lau, F.S.; Dihu, R. [Gas Technology Inst., Des Plaines, IL (United States); Bingue, J.P.; Saveliev, A.V.; Fridman, A.A.; Kennedy, L.A. [Illinois Univ., Chicago, IL (United States)

    2002-07-01

    It is expected that hydrogen will become the fuel of choice for advanced technologies. Hydrogen is currently used as feedstock in the synthesis of ammonia and methanol, in the desulfurization and hydrocracking at oil refineries, and in the upgrading of hydrocarbon resources such as heavy oil and coal. Hydrogen sulfide (H{sub 2}S) is regarded as a mineral from which both hydrogen and sulfur can be extracted. Since there are large amounts of H{sub 2}S available worldwide, significant research has gone into the development of converting hydrogen sulfide into hydrogen through thermal decomposition. The high temperature required for the reaction, however, makes the approach impractical. This paper presents results of a study using a new approach to overcome the limitations of thermal decomposition. In this newly developed process, operation at very high temperatures is possible and economical through oxidation of part of the H{sub 2}S to provide the energy needed for the decomposition reaction. Partial oxidation is carried out in the presence of an inert, porous, high-capacity medium and the heat exchange results in flame temperatures that exceed the adiabatic flame temperature of the gas mixture. This process is less stringent than the Claus process because of the required feed gas conditioning. SO{sub 2} emissions inevitably form because part of the H{sub 2}S is oxidized to generate heat. However, SO{sub 2} is not expected to form to a significant degree. It was concluded that the product/byproduct separation schemes need to be examined further to have a better idea regarding the cost of hydrogen production from this process. 6 refs., 5 figs.

  11. Photobiological production of hydrogen using cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Borthakur, D.; McKinley, K.R.; Bylina, E.J. [Univ. of Hawaii, Honolulu, HI (United States)

    1995-09-01

    Cyanobacteria are capable of generating hydrogen using sunlight and water. In both Spirulina and Anabaena, there is a soluble reversible hydrogenase that is involved in hydrogen evolution under anaerobic conditions in the dark. In addition, the nitrogen-fixing cyanobacterium Anabaena produces hydrogen as a by-product of nitrogen fixation. Most of this hydrogen is recaptured by a membrane-bound uptake hydrogenase present in Anabaena cells. Experiments have continued to develop a gene transfer system in Spirulina in preparation for improved hydrogen production via genetic manipulation of the reversible hydrogenase. We have identified and characterized four restriction enzymes in Spirulina and cloned the genes for two methylases that protect their own DNA from cleavage by restriction enzymes. We have also cloned and sequenced parts of hupB and hupM genes involved in the synthesis of uptake hydrogenase in Anabaena. Successful cloning of these hup genes represents an important and necessary step in our project because this will enable us to construct Anabaena strains with enhanced hydrogen production ability by disrupting the hup genes involved in hydrogen uptake. We are also setting up a bio-reactor to determine the amount of hydrogen released by different Spirulina and Anabaena strains under different physiological conditions.

  12. Biological hydrogen production from industrial wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Peixoto, Guilherme; Pantoja Filho, Jorge Luis Rodrigues; Zaiat, Marcelo [Universidade de Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). School of Engineering. Dept. Hydraulics and Sanitation], Email: peixoto@sc.usp.br

    2010-07-01

    This research evaluates the potential for producing hydrogen in anaerobic reactors using industrial wastewaters (glycerol from bio diesel production, wastewater from the parboilization of rice, and vinasse from ethanol production). In a complementary experiment the soluble products formed during hydrogen production were evaluated for methane generation. The assays were performed in batch reactors with 2 liters volume, and sucrose was used as a control substrate. The acidogenic inoculum was taken from a packed-bed reactor used to produce hydrogen from a sucrose-based synthetic substrate. The methanogenic inoculum was taken from an upflow anaerobic sludge blanket reactor treating poultry slaughterhouse wastewater. Hydrogen was produced from rice parboilization wastewater (24.27 ml H{sub 2} g{sup -1} COD) vinasse (22.75 ml H{sub 2} g{sup -1} COD) and sucrose (25.60 ml H{sub 2} g{sup -1} COD), while glycerol only showed potential for methane generation. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-15

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

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

    International Nuclear Information System (INIS)

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

  15. Mapping the Hydrogen Bond Networks in the Catalytic Subunit of Protein Kinase A Using H/D Fractionation Factors.

    Science.gov (United States)

    Li, Geoffrey C; Srivastava, Atul K; Kim, Jonggul; Taylor, Susan S; Veglia, Gianluigi

    2015-07-01

    Protein kinase A is a prototypical phosphoryl transferase, sharing its catalytic core (PKA-C) with the entire kinase family. PKA-C substrate recognition, active site organization, and product release depend on the enzyme's conformational transitions from the open to the closed state, which regulate its allosteric cooperativity. Here, we used equilibrium nuclear magnetic resonance hydrogen/deuterium (H/D) fractionation factors (φ) to probe the changes in the strength of hydrogen bonds within the kinase upon binding the nucleotide and a pseudosubstrate peptide (PKI5-24). We found that the φ values decrease upon binding both ligands, suggesting that the overall hydrogen bond networks in both the small and large lobes of PKA-C become stronger. However, we observed several important exceptions, with residues displaying higher φ values upon ligand binding. Notably, the changes in φ values are not localized near the ligand binding pockets; rather, they are radiated throughout the entire enzyme. We conclude that, upon ligand and pseudosubstrate binding, the hydrogen bond networks undergo extensive reorganization, revealing that the open-to-closed transitions require global rearrangements of the internal forces that stabilize the enzyme's fold. PMID:26030372

  16. Hydrogen production using ammonia borane

    Science.gov (United States)

    Hamilton, Charles W; Baker, R. Thomas; Semelsberger, Troy A; Shrestha, Roshan P

    2013-12-24

    Hydrogen ("H.sub.2") is produced when ammonia borane reacts with a catalyst complex of the formula L.sub.nM-X wherein M is a base metal such as iron, X is an anionic nitrogen- or phosphorus-based ligand or hydride, and L is a neutral ancillary ligand that is a neutral monodentate or polydentate ligand.

  17. Photo-biotechnological hydrogen production with microalgae

    Energy Technology Data Exchange (ETDEWEB)

    Lehr, F.; Posten, C. [Inst. fuer Bio- und Lebensmitteltechnik, Univ. Karlsruhe (Germany); Renz, A.; Schaub, G. [Engler-Bunte-Inst., Univ. Karlsruhe (Germany)

    2008-07-01

    Some types of unicellular green algae have evolved the ability to use solar energy to produce hydrogen by splitting water. Compared to photosynthesis with terrestrial plants, microalgal hydrogen production exhibits higher photo conversion efficiencies, very low water demands, and no competition with agriculture for arable land use. The overall process includes microalgae growth by photosynthesis and subsequent hydrogen production. The main challenge in process development is the design of photo bioreactors with minimum energy demand for mixing and liquid handling and maximum overall efficiency. In an ongoing research project, process engineering fundamentals are presently being investigated in order to allow more accurate process design and cost estimates. (orig.)

  18. Fermentative hydrogen production by diverse microflora

    Energy Technology Data Exchange (ETDEWEB)

    Baghchehsaraee, B.; Nakhla, G.; Karamanev, D.; Margaritis, A. [Dept. of Chemical and Biochemical Engineering, Univ. of Western Ontario, London, Ontario (Canada)

    2009-07-01

    'Full text': In this study of hydrogen production with activated sludge, a diverse bacterial source has been investigated and compared to microflora from anaerobic digester sludge, which is less diverse. Batch experiments were conducted at mesophilic (37 {sup o}C) and thermophilic (55 {sup o}C) temperatures. The hydrogen production yields with activated sludge at 37 {sup o}C and 55 {sup o}C were 0.25 and 0.93 mol H{sub 2}/mol glucose, respectively. The maximum hydrogen production rates with activated sludge in both temperatures were 4.2 mL/h. Anaerobic digester sludge showed higher hydrogen production yields and rates at both mesophilic and thermophilic temperatures. The results of repeated batch experiments with activated sludge showed an increase in the hydrogen production during the consecutive batches. However, hydrogen production was not stable along the repeated batches. The observed instability was due to the formation of lactic acid and ethanol. (author)

  19. Catalytic applications in the production of biodiesel from vegetable oils.

    Science.gov (United States)

    Sivasamy, Arumugam; Cheah, Kien Yoo; Fornasiero, Paolo; Kemausuor, Francis; Zinoviev, Sergey; Miertus, Stanislav

    2009-01-01

    The predicted shortage of fossil fuels and related environmental concerns have recently attracted significant attention to scientific and technological issues concerning the conversion of biomass into fuels. First-generation biodiesel, obtained from vegetable oils and animal fats by transesterification, relies on commercial technology and rich scientific background, though continuous progress in this field offers opportunities for improvement. This review focuses on new catalytic systems for the transesterification of oils to the corresponding ethyl/methyl esters of fatty acids. It also addresses some innovative/emerging technologies for the production of biodiesel, such as the catalytic hydrocracking of vegetable oils to hydrocarbons. The special role of the catalyst as a key to efficient technology is outlined, together with the other important factors that affect the yield and quality of the product, including feedstock-related properties and various system conditions. PMID:19360707

  20. Recent Developments in Biological Hydrogen Production Processes

    Directory of Open Access Journals (Sweden)

    DEBABRATA DAS

    2008-07-01

    Full Text Available Biohydrogen production technology can utilize renewable energy sources like biomass for the generation of hydrogen, the cleanest form of energy for the use of mankind. However, major constraints to the commercialization of these processes include lower hydrogen yields and rates of hydrogen production. To overcome these bottlenecks intensive research work has already been carried out on the advancement of these processes such as the development of genetically modified microorganisms, the improvement of the bioreactor design, molecular engineering of the key enzyme hydrogenases, the development of two stage processes, etc. The present paper explores the recent advancements that have been made till date and also presents the state of the art in molecular strategies to improve the hydrogen production.

  1. Swine manure fermentation for hydrogen production.

    Science.gov (United States)

    Zhu, Jun; Li, Yecong; Wu, Xiao; Miller, Curtis; Chen, Paul; Ruan, Roger

    2009-11-01

    Biohydrogen fermentation using liquid swine manure as substrate supplemented with glucose was investigated in this project. Experiments were conducted using a semi-continuously-fed fermenter (8L in total volume and 4 L in working volume) with varying pHs from 4.7 through 5.9 under controlled temperature (35+/-1 degrees C). The hydraulic retention time (HRT) tested include 16, 20, and 24h; however, in two pH conditions (5.0 and 5.3), an additional HRT of 12h was also tried. The experimental design combining HRT and pH provided insight on the fermenter performance in terms of hydrogen generation. The results indicated that both HRT and pH had profound influences on fermentative hydrogen productivity. A rising HRT would lead to greater variation in hydrogen concentration in the offgas and the best HRT was found to be 16 h for the fermenter in this study. The best pH value in correspondence to the highest hydrogen generation was revealed to be 5.0 among all the pHs studied. There was no obvious inhibition on hydrogen production by methanogenesis when methane content in the offgas was lower than 2%. Otherwise, an inverse linear relationship between hydrogen and methane content was observed with a correlation coefficient of 0.9699. Therefore, to increase hydrogen content in the offgas, methane production has to be limited to below 2%. PMID:19157863

  2. PREPARATION AND CATALYTIC BEHAVIOUR OF POLYMER-BOUND METALLOPORPHYRIN IN HYDROGENATION OF OLEFIN

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The meso-tetraarylporphyrin has been anchored to styrene-divinylbenzene copolymers by reaction of meso-tetra(4-hydroxylphenyl) porphyrin with chloromethylated resin under mild condition. A number of polymer transition metal complexes have been prepared with the polymer ligand and metal salts. The polymeric ligand and its complexes have been characterized by electronic spectra, and vibrational spectra. Cyclohexene can be hydrogenated with the polymeric porphyrin palladium complex(P-THPPPd) as catalyst, and its catalytic activity was influenced by the polarity of solvents, the contents of water in ethanol or reaction temperature. However, its catalytic activity was lower for nitro groups, carbonyl groups and olefins with steric hindrance substituents, and showed no activity for aromatic rings under these conditions.

  3. South Africa's nuclear hydrogen production development programme

    International Nuclear Information System (INIS)

    In May 2007 the South African Cabinet approved a National Hydrogen and Fuel Cell Technologies R and D and Innovation Strategy. The strategy will focus on research, development and innovation for: i) wealth creation through high value-added manufacturing and developing platinum group metals catalysis; ii) building on the existing knowledge in high temperature gas-cooled reactors (HTGR) and coal gasification Fischer-Tropsch technology, to develop local cost-competitive hydrogen production solutions; iii) to promote equity and inclusion in the economic benefits from South Africa's natural resource base. As part of the roll-out strategy, the South African Department of Science and Technology (DST) created three Competence Centres (CC), including a Hydrogen Infrastructure Competence Centre hosted by the North-West University (NWU) and the Council for Scientific and Industrial Research (CSIR). The Hydrogen Infrastructure CC is tasked with developing hydrogen production, storage, distribution as well as codes and standards programmes within the framework of the DST strategic objectives to ensure strategic national innovation over the next fifteen years. One of the focus areas of the Hydrogen Infrastructure CC will be on large scale CO2 free hydrogen production through thermochemical water-splitting using nuclear heat from a suitable heat source such as a HTGR and the subsequent use of the hydrogen in applications such as the coal-to-liquid process and the steel industry. This paper will report on the status of the programme for thermochemical water-splitting as well as the associated projects for component and technology development envisaged in the Hydrogen Infrastructure CC. The paper will further elaborate on current and future collaboration opportunities as well as expected outputs and deliverables. (authors)

  4. Marrying gas power and hydrogen energy: A catalytic system for combining methane conversion and hydrogen generation

    NARCIS (Netherlands)

    J. Beckers; C. Gaudillère; D. Farrusseng; G. Rothenberg

    2009-01-01

    Ceria-based catalysts are good candidates for integrating methane combustion and hydrogen generation. These new, tuneable catalysts are easily prepared. They are robust inorganic crystalline materials, and perform well at the 400 °C-550 °C range, in some cases even without precious metals. This make

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-08-01

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

  6. Microbial consortia for hydrogen production enhancement.

    Science.gov (United States)

    Rajhi, Haifa; Díaz, Emiliano E; Rojas, Patricia; Sanz, José L

    2013-07-01

    Ten efficient hydrogen-producing strains affiliated to the Clostridium genus were used to develop consortia for hydrogen production. In order to determine their saccharolytic and proteolytic activities, glucose and meat extract were tested as fermentation substrates, and the best hydrogen-producing strains were selected. The C. roseum H5 (glucose-consuming) and C. butyricum R4 (protein-degrading) co-culture was the best hydrogen-producing co-culture. The end-fermentation products for the axenic cultures and co-cultures were analyzed. In all cases, organic acids, mainly butyrate and acetate, were produced lowering the pH and thus inhibiting further hydrogen production. In order to replace the need for reducing agents for the anaerobic growth of clostridia, a microbial consortium including Clostridium spp. and an oxygen-consuming microorganism able to form dense granules (Streptomyces sp.) was created. Increased yields of hydrogen were achieved. The effect of adding a butyrate-degrading bacteria and an acetate-consuming archaea to the consortia was also studied.

  7. Continuous hydrogen production from starch by fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Keigo; Tanisho, Shigeharu [Yokohama National Univ. (Japan)

    2010-07-01

    This study was investigated the effect of hydraulic retention time (HRT) on hydrogen production rate, hydrogen yield and the production rate of volatile fatty acid. The experiment was performed in a continuous stirred tank reactor (CSTR) with a working volume of 1 L by using a Clostridium sp. The temperature of the CSTR was regulated 37 C. The pH was controlled 6.0 by the addition of 3 M of NaOH solution. Starch was used as the carbon source with the concentration of 30 g L{sup -1}. Hydrogen production rate increased from 0.9 L-H{sub 2} L-culture{sup -1} h{sup -1} to 3.2 L-H{sub 2} L-culture{sup -1} h{sup -1} along with the decrease of HRT from 9 h to 1.5 h. Hydrogen yield decreased at low HRT. The major volatile fatty acids are acetic acid, butyric acid and lactic acid. The production rates of acetic acid and butyric acid increased along with the decrease of HRT. On the other hand, the rate of lactic acid was low at high HRT while it increased at HRT 1.5 h. The increase of the production rate of lactic acid suggested one of the reasons that hydrogen yield decreased. (orig.)

  8. Development of a para-orthohydrogen catalytic converter for a solid hydrogen cooler

    Science.gov (United States)

    Nast, T. C.; Hsu, I. C.

    1984-01-01

    Design features of a tested catalytic converter for altering vented cryogenic parahydrogen used as a coolant on spacecraft into a para-ortho equilibrium for channeling to other cooling functions are described. The hydrogen is expected to be stored in either liquid or solid form. A high surface area Ni-on-Si catalyst was selected for tests at an operating pressure of 2 torr at a ratio of 1000 gr catalyst for a gr/sec hydrogen flow. Cylindrical and radial flow geometries were tried and measurements centered on the converter efficiencies at different operating temperatures when the converter was placed in the vent line of the H2 cooler. Efficiencies ranging from 10-100 percent were obtained for varying flow rates. Further testing is necessary to characterize the converter performance under a wider range of operating temperatures and environments.

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

    Directory of Open Access Journals (Sweden)

    Salmi T.

    2000-01-01

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

  10. Application of transition metal ferrites AFe2O4 (A= Co, Ni, Cu) for the catalytic decomposition of sulphuric acid involved in sulphur-iodine thermochemical cycle for nuclear hydrogen production

    International Nuclear Information System (INIS)

    Spinel ferrites with general formula AFe2O4 (A= Co, Ni, Cu) were prepared by glycine-nitrate gel combustion method and characterized using powder XRD, FTIR, SEM and Mossbauer spectroscopy. The redox properties of the samples were studied by recording multiple TPR/O cycles. The copper ferrite sample was found to be the most easily reducible sample with Tmax for reduction occurring at the lowest temperature among all samples. The catalytic activity of all the samples were evaluated for sulphuric acid decomposition reaction in the temperature range of 650 deg C-825 deg C. Copper ferrite was found to be the most active catalyst for the reaction with ∼ 78% conversion at 800 deg C. (author)

  11. Onboard Plasmatron Hydrogen Production for Improved Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Daniel R. Cohn; Leslie Bromberg; Kamal Hadidi

    2005-12-31

    A plasmatron fuel reformer has been developed for onboard hydrogen generation for vehicular applications. These applications include hydrogen addition to spark-ignition internal combustion engines, NOx trap and diesel particulate filter (DPF) regeneration, and emissions reduction from spark ignition internal combustion engines First, a thermal plasmatron fuel reformer was developed. This plasmatron used an electric arc with relatively high power to reform fuels such as gasoline, diesel and biofuels at an oxygen to carbon ratio close to 1. The draw back of this device was that it has a high electric consumption and limited electrode lifetime due to the high temperature electric arc. A second generation plasmatron fuel reformer was developed. It used a low-current high-voltage electric discharge with a completely new electrode continuation. This design uses two cylindrical electrodes with a rotating discharge that produced low temperature volumetric cold plasma., The lifetime of the electrodes was no longer an issue and the device was tested on several fuels such as gasoline, diesel, and biofuels at different flow rates and different oxygen to carbon ratios. Hydrogen concentration and yields were measured for both the thermal and non-thermal plasmatron reformers for homogeneous (non-catalytic) and catalytic reforming of several fuels. The technology was licensed to an industrial auto part supplier (ArvinMeritor) and is being implemented for some of the applications listed above. The Plasmatron reformer has been successfully tested on a bus for NOx trap regeneration. The successful development of the plasmatron reformer and its implementation in commercial applications including transportation will bring several benefits to the nation. These benefits include the reduction of NOx emissions, improving engine efficiency and reducing the nation's oil consumption. The objective of this program has been to develop attractive applications of plasmatron fuel reformer

  12. Thermodynamic Investigation of Hydrogen Production by Methane Steam Reforming using Integrated Hydrogen-permselective Membrane Reactor with CO2 absorption

    International Nuclear Information System (INIS)

    The role of hydrogen as an energy carrier became more important to the future energy system. Methane steam reforming (MSR) is one of the most important chemical processes in hydrogen production. To improve the conversion of methane to hydrogen, a hydrogen-permselective membrane reactor with a carbon dioxide absorbent was proposed and investigated. The conversion at 893 K in the integrated reactor with CaO as absorbent was almost equal to that at above 1000 K in the conventional reactor. Exergy analyses indicated that the a large portion of exergy loss for hydrogen production was chemical exergy loss in the case without methane recycle, while thermal exergy loss in the case with recycle use. The exergy loss of this process using the hydrogen-permselective membrane reactor with the CaO-absorbent was estimated about 70% of that by the conventional catalytic reactor. Efficiencies of the integrated reactor process, based on the energy and exergy losses were compared with those of other hydrogen production processes. (authors)

  13. Biomass-to-hydrogen via fast pyrolysis and catalytic steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Chornet, E.; Wang, D.; Czernik, S. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-10-01

    Pyrolysis of lignocellulosic biomass and reforming the pyroligneous oils is being studied as a strategy for producing hydrogen. Novel technologies for the rapid pyrolysis of biomass have been developed in the past decade. They provide compact and efficient systems to transform biomass into vapors that are condensed to oils, with yields as high as 75-80 wt.% of the anhydrous biomass. This {open_quotes}bio-oil{close_quotes} is a mixture of aldehydes, alcohols, acids, oligomers from the constitutive carbohydrates and lignin, and some water derived from the dehydration reactions. Hydrogen can be produced by reforming the bio-oil or its fractions with steam. A process of this nature has the potential to be cost competitive with conventional means of producing hydrogen. The reforming facility can be designed to handle alternate feedstocks, such as natural gas and naphtha, if necessary. Thermodynamic modeling of the major constituents of the bio-oil has shown that reforming is possible within a wide range of temperatures and steam-to-carbon ratios. Existing catalytic data on the reforming of oxygenates have been studied to guide catalyst selection. Tests performed on a microreactor interfaced with a molecular beam mass spectrometer showed that, by proper selection of the process variables: temperature, steam-to-carbon ratio, gas hourly space velocity, and contact time, almost total conversion of carbon in the feed to CO and CO{sub 2} could be obtained. These tests also provided possible reaction mechanisms where thermal cracking competes with catalytic processes. Bench-scale, fixed bed reactor tests demonstrated high hydrogen yields from model compounds and carbohydrate-derived pyrolysis oil fractions. Reforming bio-oil or its fractions required proper dispersion of the liquid to avoid vapor-phase carbonization of the feed in the inlet to the reactor. A special spraying nozzle injector was designed and successfully tested with an aqueous fraction of bio-oil.

  14. Fermentative hydrogen production by diverse microflora

    Energy Technology Data Exchange (ETDEWEB)

    Baghchehsaraee, Bita; Nakhla, George; Karamanev, Dimitre; Margaritis, Argyrios [Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, Ontario N6A 5B9 (Canada)

    2010-05-15

    In this study, hydrogen production with activated sludge, a diverse bacterial source has been investigated and compared to microflora from anaerobic digester sludge, which is less diverse. Batch experiments were conducted at mesophilic (37 C) and thermophilic (55 C) temperatures. The hydrogen production yields with activated sludge at 37 C and 55 C were 0.56 and 1.32 mol H{sub 2}/mol glucose consumed, respectively. While with anaerobically digested sludge hydrogen yield was 2.18 mol H{sub 2}/mol glucose consumed at 37 C and 1.25 mol H{sub 2}/mol glucose consumed at 55 C. The results of repeated batch experiments for 615 h resulted in average yields of 1.21 {+-} 0.62 and 1.40 {+-} 0.16 mol H{sub 2}/mol glucose consumed for activated sludge and anaerobic sludge, respectively. The hydrogen production with activated sludge was not stable during the repeated batches and the fluctuation in hydrogen production was attributed to formation of lactic acid as the predominant metabolite in some batches. The presence of lactic acid bacteria in microflora was confirmed by PCR-DGGE. (author)

  15. Systematic Discrimination of Advanced Hydrogen Production Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Charles V. Park; Michael W. Patterson

    2010-07-01

    The U.S. Department of Energy, in concert with industry, is developing a high-temperature gas-cooled reactor at the Idaho National Laboratory (INL) to demonstrate high temperature heat applications to produce hydrogen and electricity or to support other industrial applications. A key part of this program is the production of hydrogen from water that would significantly reduce carbon emissions compared to current production using natural gas. In 2009 the INL led the methodical evaluation of promising advanced hydrogen production technologies in order to focus future resources on the most viable processes. This paper describes how the evaluation process was systematically planned and executed. As a result, High-Temperature Steam Electrolysis was selected as the most viable near-term technology to deploy as a part of the Next Generation Nuclear Plant Project.

  16. Effect of hydrogen combustion reaction on the dehydrogenation of ethane in a fixed-bed catalytic membrane reactor

    Institute of Scientific and Technical Information of China (English)

    Masoud Hasany; Mohammad Malakootikhah; Vahid Rahmanian; Soheila Yaghmaei

    2015-01-01

    A two-dimensional non-isothermal mathematical model has been developed for the ethane dehydrogenation reaction in a fixed-bed catalytic membrane reactor. Since ethane dehydrogenation is an equilibrium reaction, removal of produced hydrogen by the membrane shifts the thermodynamic equilibrium to ethylene production. For further displacement of the dehydrogenation reaction, oxidative dehydrogenation method has been used. Since ethane dehydrogenation is an endothermic reaction, the energy produced by the oxidative dehydrogena-tion method is consumed by the dehydrogenation reaction. The results show that the oxidative dehydrogenation method generated a substantial improvement in the reactor performance in terms of high conversions and significant energy saving. It was also established that the sweep gas velocity in the shell side of the reactor is one of the most important factors in the effectiveness of the reactor.

  17. Use of nuclear energy for hydrogen production

    International Nuclear Information System (INIS)

    Full text: The potential of three hydrogen production processes, under development for the industrial production of hydrogen using nuclear energy, are compared and evaluated in this paper, namely: advanced electrolysis, steam reforming, and sulfur-iodine water splitting cycle. Water electrolysis and steam reforming of methane are proven and used extensively for the production of hydrogen today. The overall thermal efficiency of the electrolysis includes the efficiency of the electrical power generation and of the electrolysis itself. The electrolysis process efficiency is about 75 % and of electrical power generation is only about 30 %, the overall thermal efficiency for H2 generation being about 25 %. Steam reforming process consists of reacting methane (or natural gas) and steam in a chemical reactor at 800 - 900 deg C, with a thermal efficiency of about 70 %. In a reforming process, with heat supplied by nuclear reactor, the heat must be supplied by a secondary loop from the nuclear side and be transferred to the methane/steam mixture, via heat exchanger type reactor. The sulfur-iodine (S-I) cycle, a thermochemical water splitting, is of particular interest because it produces hydrogen efficiently with no CO2 as byproduct. If heated with a nuclear source it could prove to be an ideal environmental solution to hydrogen production. Steam reforming remains the cheapest hydrogen production method based on the latest estimates, even when implemented with nuclear reactor. The S-I cycle offers a close second and the electrolysis is the most expensive of the options for industrial H2 production. The nuclear plant could power electrolysis operations right away. Steam reforming with nuclear power is a little bit further off into the future, the first operation expected with nuclear facility is in Japan in 2008. The S-I cycle implementation is still over the horizon, it will be more than 10 years until we will see that cycle in full scale operation with a nuclear reactor

  18. On-line catalytic upgrading of biomass fast pyrolysis products

    Institute of Scientific and Technical Information of China (English)

    LU Qiang; ZHU XiFeng; LI WenZhi; ZHANG Ying; CHEN DengYu

    2009-01-01

    Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was employed to achieve fast pyrolysis of biomass and on-line analysis of the pyrolysis vapors. Four biomass materials (poplar wood, fir wood, cotton straw and rice husk) were pyrolyzed to reveal the difference among their products. Moreover, catalytic cracking of the pyrolysis vapors from cotton straw was performed by using five catalysts, including two microporous zeolites (HZSM-5 and HY) and three mesoporous catalysts (ZrO2&TiO2, SBA-15 and AI/SBA-15). The results showed that the distribution of the pyrolytic products from the four materials differed a little from each other, while catalytic cracking could significantly alter the pyrolytic products. Those important primary pyrolytic products such as levoglucosen, hydroxyacetaldehyde and 1-hydroxy-2-propanone were decreased greatly after catalysis. The two microporous zeolites were ef-fective to generate high yields of hydrocarbons, while the three mesoporous materials favored the formation of furan, furfural and other furan compounds, as well as acetic acid.

  19. Simulation of hydrogen mitigation in catalytic recombiner: Part-I: Surface chemistry modelling

    Energy Technology Data Exchange (ETDEWEB)

    Prabhudharwadkar, Deoras M. [Department of Mechanical Engineering, Indian Institute of Technology-Bombay, Powai, Mumbai 400076, Maharashtra (India); Aghalayam, Preeti A. [Department of Chemical Engineering, Indian Institute of Technology-Bombay, Powai, Mumbai 400076 (India); Iyer, Kannan N., E-mail: kiyer@iitb.ac.i [Department of Mechanical Engineering, Indian Institute of Technology-Bombay, Powai, Mumbai 400076, Maharashtra (India)

    2011-05-15

    This paper aims at accurate modelling of a Passive Catalytic Recombiner used for hydrogen mitigation in the nuclear power plant containments. In order to assess the performance of the recombiner through numerical simulations, it is required to accurately predict the catalytic reactions. There are various detailed reaction mechanisms available in the literature for prediction of hydrogen-oxygen reaction over a platinum surface. While a single step reaction rate expression is always sought in order to obtain numerical predictions economically, a detailed reaction mechanism that includes several elementary reactions and intermediate species is likely to produce more accurate predictions. The paper compares the solution from two of competing models, one a single step reaction and the other a multiple reaction model. A new single step rate expression is also derived from the detailed mechanism after simplifying it for the present problem. The paper also considers the diffusion controlled model that assumes rapid reaction rates for which the surface chemistry is not required at all. In order to find the best suited approach to model the surface chemistry, CFD simulations were performed with FLUENT code using available experimental data from the literature. The current study reports comparison up to 4% H{sub 2} mole fraction in dry air with catalyst temperature varying from 300 K to 800 K. It is demonstrated that the new single step model is able to satisfactorily predict the data as well as the detailed chemistry model. The diffusion controlled model is shown to over-predict the data.

  20. Catalytic hydrotreating of waste cooking oil for renewable diesel production

    Energy Technology Data Exchange (ETDEWEB)

    Bezergianni, Stella; Dimitriadis, Athanasios [Centre for Research and Technology Hellas (CERTH), Thessaloniki (Greece)

    2013-06-01

    A new technology based on catalytic hydrotreating of Waste Cooking Oil (WCO) for biodiesel production has been developed in the Centre for Research and Technology Hellas (CERTH). The main premise of this process is the conversion of the WCO fatty acids into normal- and iso-paraffins. The technology was evaluated in hydroprocessing pilot plants of CERTH where feedstock origin as well as optimal catalysts and operating parameters where identified. The fractionated diesel product, called ''white'' diesel exhibits excellent fuel properties including higher heating value (over 49 MJ/kg), negligible acidity, higher oxidation stability and higher cetane number ({proportional_to}77) than conventional biodiesel. The overall product yield is {proportional_to}92% v/v. This new suggested technology is extremely appealing as it employs existing refinery infrastructure and expertise, offers feedstock flexibility, leaves no by-product and above all is economically attractive. (orig.)

  1. Study of hydrogen production at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Raoui, M.; Belhamel [Centre de Developpement des Energies Renouvelables, BP 62 route de l observatoire Village celleste, Bouzareah Alger, (Algeria); Miri [Universite des sciences et de la technologie houari boumediene, Alger, (Algeria); Benyoucef [Universite de Tlemcen, Tlemcen, (Algeria)

    2006-07-01

    In this study, we evaluate the hydrogen production per electrolysis at high temperature. The increase in the pressure and the temperature of water are done by a solar power station, the electrolysis of water is done at high temperature 900 C 30 bars. We carry out the design of a generating station of hydrogen treating a flow rate of 1 kg/s of water vapour, then we simulate the production of this installation in various towns of Algeria. The results show the great potential energy of the cities of the Algerian south. (authors)

  2. Hydrogen production by aqueous phase reforming of light oxygenated hydrocarbons

    Science.gov (United States)

    Shabaker, John William

    Aqueous phase reforming (APR) of renewable oxygenated hydrocarbons (e.g., methanol, ethylene glycol, glycerol, sorbitol, glucose) is a promising new technology for the catalytic production of high-purity hydrogen for fuel cells and chemical processing. Supported Pt catalysts are effective catalysts for stable and rapid H2 production at temperatures near 500 K (H 2 turnover frequencies near 10 min-1). Inexpensive Raney Ni-based catalysts have been developed using a combination of fundamental and high-throughput studies that have similar catalytic properties as Pt-based materials. Promotion of Raney Ni with Sn by controlled surface reaction of organometallic tin compounds is necessary to control formation of thermodynamically-favorable alkane byproducts. Detailed characterization by Mossbauer spectroscopy, electron microscopy, adsorption studies, and x-ray photoelectron spectroscopy (XPS/ESCA) has shown that NiSn alloys are formed during heat treatment, and may be responsible for enhanced stability and selectivity for hydrogen production. Detailed kinetic studies led to the development of a kinetic mechanism for the APR reaction on Pt and NiSn catalysts, in which the oxygenate decomposes through C--H and O--H cleavage, followed by C--C cleavage and water gas shift of the CO intermediate. The rate limiting step on Pt surfaces is the initial dehydrogenation, while C--C cleavage appears rate limiting over NiSn catalysts. Tin promotion of Raney Ni catalysts suppresses C--O bond scission reactions that lead to alkane formation without inhibiting fast C--C and C--H cleavage steps that are necessary for high rates of reforming. A window of operating temperature, pressure, and reactor residence time has been identified for use of the inexpensive NiSn catalysts as a Pt substitute. Concentrated feed stocks and aggressive pretreatments have been found to counteract catalyst deactivation by sintering in the hydrothermal APR environment and allow stable, long-term production of H

  3. Simulation of hydrogen mitigation in catalytic recombiner. Part-II: Formulation of a CFD model

    Energy Technology Data Exchange (ETDEWEB)

    Prabhudharwadkar, Deoras M. [Department of Mechanical Engineering, Indian Institute of Technology-Bombay, Powai, Mumbai 400076 (India); Iyer, Kannan N., E-mail: kiyer@me.iitb.ac.i [Department of Mechanical Engineering, Indian Institute of Technology-Bombay, Powai, Mumbai 400076 (India)

    2011-05-15

    Research highlights: Hydrogen transport in containment with recombiners is a multi-scale problem. A novel methodology worked out to lump the recombiner characteristics. Results obtained using commercial code FLUENT are cast in the form of correlations. Hence, coarse grids can obtain accurate distribution of H{sub 2} in containment. Satisfactory working of the methodology is clearly demonstrated. - Abstract: This paper aims at formulation of a model compatible with CFD code to simulate hydrogen distribution and mitigation using a Passive Catalytic Recombiner in the Nuclear power plant containments. The catalytic recombiner is much smaller in size compared to the containment compartments. In order to fully resolve the recombination processes during the containment simulations, it requires the geometric details of the recombiner to be modelled and a very fine mesh size inside the recombiner channels. This component when integrated with containment mixing calculations would result in a large number of mesh elements which may take large computational times to solve the problem. This paper describes a method to resolve this simulation difficulty. In this exercise, the catalytic recombiner alone was first modelled in detail using the best suited option to describe the reaction rate. A detailed parametric study was conducted, from which correlations for the heat of reaction (hence the rate of reaction) and the heat transfer coefficient were obtained. These correlations were then used to model the recombiner channels as single computational cells providing necessary volumetric sources/sinks to the energy and species transport equations. This avoids full resolution of these channels, thereby allowing larger mesh size in the recombiners. The above mentioned method was successfully validated using both steady state and transient test problems and the results indicate very satisfactory modelling of the component.

  4. Effects of acido-basic support properties on the catalytic hydrogenation of acetylene on gold nano-particles

    Science.gov (United States)

    Manda, Abdullah Ahmed

    Metallic gold nanoparticles supported on gamma-Al2O 3 and magnesia-alumina mixed oxide, with different magnesia content have been prepared by sol-gel method and characterized by different techniques (inductive coupled plasma-mass spectroscopy (ICP-MS), XRD, BET surface area analysis, transmission electron microscopy (TEM), CO2 and NH 3 temperature programmed desorption (TPD), H2 temperature programmed reduction (TPR) and FTIR of adsorbed CO2). Such systems were found to produce catalysts with controllable acidity, varying from catalyst possessing large density of acidic and low density of basic sites, others with acidic and basic sites of equal strength and density, and others with large basic and low acid sites densities, respectively. The catalytic assessment of the generated acidity was carried out using 2-propanol decomposition as a test reaction. The results obtained indicate that the presence of magnesia and reduced gold nanopartilces has imparted the catalysts, 1%Au/4%Mg-Al 2O3 and 1%Au/8%Mg-Al2O3, with significant base-catalytic properties. Acetylene hydrogenation and formation of coke deposits were investigated on a gold catalyst supported on gamma-Al2O3 and gold supported on alumina-magnisia mixed oxide with different gold content; 1%Au/gamma-Al 2O3, 1%Au/15%Mg-Al2O3, 2%Au/15%Mg-Al 2O3 and 4%Au/15%Mg-Al2O3. The effect of the H2/C2H2 ratio was studied over a range of values. The catalytic activity and selectivity towards ethylene and other products were investigated at different reaction temperatures. Acetylene hydrogenation was investigated in the presence and absence of ethylene in stream. It is investigated that the adsorption of the triple bond is preferred over the double bond and during selective catalytic (SCR) of C2H2 the two hydrocarbons do not compete for the same adsorption sites. The deactivation of catalysts was studied by temperature programmed oxidation (TPO). Higher content of coke over 1%Au/Al2O3 catalyst was investigated in contrast to

  5. Production of pure hydrogen by ethanol dehydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Santacesaria, Elio; Carotenuto, Giuseppina; Tesser, Riccardo; Di Serio, Martino [Naples Univ. (Italy). Dipt. di Chimica

    2011-06-15

    Hydrogen production from bio-ethanol is one of the most promising renewable processes to generate electricity using fuel cells. In this work, we have studied the production of pure hydrogen as a by-product of the ethanol dehydrogenation reaction. This reaction is promoted by copper based catalysts and according to the catalyst used and the operating conditions gives place to acetaldehyde or ethyl acetate as main products. We studied in particular the performance of a commercial copper/copper chromite catalyst, supported on alumina and containing barium chromate as a promoter, which gave the best results. By operating at low pressure and temperature with short residence times, acetaldehyde is more selectively produced, while, by increasing the pressure (10-30 bars), the temperature (200-260 C) and the residence time (about 100 grams hour/mol of ethanol contact time) the selectivity is shifted to the production of ethyl acetate. However, in both cases pure hydrogen is obtained, as a by-product, which can easily be separated. Hydrogen obtained in this way is free of CO and can be directly fed to fuel cells without any inconvenience. In this work, runs performed under different operating conditions have been reported with the scope to select the best conditions. A carrier of H2 6% in N{sub 2} has been used. The studied catalyst has also shown a good thermal stability with respect to sintering phenomena, which generally occur during the dehydrogenation over other copper catalysts. Hydrogen productivities of 8-39 g{sub H2} (Kgcat){sup -1} (h){sup -1} were obtained for the explored temperature range of 200-260 C. Finally the most accredited reaction mechanism is reported and discussed on the basis of the obtained results. (orig.)

  6. Hydrogen production by fermentative consortia

    Energy Technology Data Exchange (ETDEWEB)

    Valdez-Vazquez, Idania [Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE), Department of Marine Biotechnology, Ensenada, B.C. Mexico (Mexico); Poggi-Varaldo, Hector M. [CINVESTAV-IPN, Department of Biotechnology and Bioengineering, PO Box 14-740, Mexico D.F. 07000 (Mexico)

    2009-06-15

    In this work, H{sub 2} production by anaerobic mixed cultures was reviewed. First, the different anaerobic microbial communities that have a direct relation with the generation or consumption of H{sub 2} are discussed. Then, the different methods used to inhibit the H{sub 2}-consuming bacteria are analyzed (mainly in the methanogenesis phase) such as biokinetic control (low pH and short hydraulic retention time), heat-shock treatment and chemical inhibitors along with their advantages/disadvantages for their application on an industrial scale. After that, biochemical pathways of carbohydrate degradation to H{sub 2}, organic acids and solvents are showed. Fourth, structure, diversity and dynamics of H{sub 2}-producers communities are detailed. Later, the hydrogenase structure and activity is related with H{sub 2} production. Also, the causes for H{sub 2} production inhibition are analyzed along with strategies to avoid it. Finally, immobilized-cells systems are presented as a way to enhance H{sub 2} production. (author)

  7. Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yan; Chang, Jie; Ouyang, Yong; Zheng, Xianwei [South China Univ. of Technology, Guangzhou (China)

    2014-06-15

    High value-added aromatic aldehydes (e. g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide (H{sub 2}O{sub 2}) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin (Co(TPPS{sub 4})) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without Co(TPPS{sub 4}). Moreover, a possible mechanism of HFBO oxidation using Co(TPPS{sub 4})/H{sub 2}O{sub 2} was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under Co(TPPS{sub 4})/H{sub 2}O{sub 2} system.

  8. Technical Integration of Nuclear Hydrogen Production Technology

    International Nuclear Information System (INIS)

    These works focus on the development of attainment indices for nuclear hydrogen key technologies, the analysis of the hydrogen production process and the performance estimation for hydrogen production systems, and the assessment of the nuclear hydrogen production cost. For assessing the degree of attainments in comparison with the final goals of VHTR technologies in progress of researches, subdivided are the prerequisite items confirmed to the NHDD concepts. We developed and applied R and D quality management methodology to meet 'Development of Key Technologies for Nuclear Hydrogen' project. And we also distributed R and D QAM and R and D QAP to each teams and are in operation. The preconceptual flow diagrams of SI, HTSE, and HyS processes are introduced and their material and energy balances have been proposed. The hydrogen production thermal efficiencies of not only the SI process as a reference process but also the HTSE and HyS processes were also estimated. Technical feasibility assessments of SI, HTSE, and HyS processes have been carried out by using the pair-wise comparison and analytic hierarchy process, and it is revealed that the experts are considering the SI process as the most feasible process. The secondary helium pathway across the SI process is introduced. Dynamic simulation codes for the H2S04vaporizer, sulfuric acid and sulfur trioxide decomposers, and HI decomposer on the secondary helium pathway and for the primary and secondary sulfuric acid distillation columns, HIx solution distillation column, and preheater for HI vapor have been developed and integrated

  9. CATALYTIC INTERACTIONS OF RHODIUM, RUTHENIUM, AND MERCURY DURING SIMULATED DWPF CPC PROCESSING WITH HYDROGEN GENERATION

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D

    2008-10-09

    Simulations of the Defense Waste Processing Facility (DWPF) Chemical Processing Cell (CPC) vessels were performed as part of the ongoing investigation into catalytic hydrogen generation. Rhodium, ruthenium, and mercury have been identified as the principal elemental factors affecting the peak hydrogen generation rate in the DWPF Sludge Receipt and Adjustment Tank (SRAT) for a given acid addition. The primary goal of this study is to identify any significant interactions between the three factors. Noble metal concentrations were similar to recent sludge batches. Rh ranged from 0.0026-0.013% and Ru ranged from 0.010-0.050% in the dried sludge solids, while initial Hg ranged from 0.5-2.5 wt%. An experimental matrix was developed to ensure that the existence of statistically significant two-way interactions could be determined without confounding of the main effects with the two-way interaction effects. The nominal matrix design consisted of twelve SRAT cycles. Testing included: a three factor (Rh, Ru, and Hg) study at two levels per factor (eight runs), two duplicate midpoint runs, and two additional replicate runs to assess reproducibility away from the midpoint. Midpoint testing can identify potential quadratic effects from the three factors. A single sludge simulant was used for all tests. Acid addition was kept effectively constant except to compensate for variations in the starting mercury concentration. Six Slurry Mix Evaporator (SME) cycles were performed to supplement the SME hydrogen generation database. Some of the preliminary findings from this study include: (1) Rh was linked to the maximum SRAT hydrogen generation rate in the first two hours after acid addition in preliminary statistical modeling. (2) Ru was linked conclusively to the maximum SRAT hydrogen generation rate in the last four hours of reflux in preliminary statistical modeling. (3) Increasing the ratio of Hg/Rh shifted the noble metal controlling the maximum SRAT hydrogen generation rate from

  10. Reactors Save Energy, Costs for Hydrogen Production

    Science.gov (United States)

    2014-01-01

    While examining fuel-reforming technology for fuel cells onboard aircraft, Glenn Research Center partnered with Garrettsville, Ohio-based Catacel Corporation through the Glenn Alliance Technology Exchange program and a Space Act Agreement. Catacel developed a stackable structural reactor that is now employed for commercial hydrogen production and results in energy savings of about 20 percent.

  11. Hydrogen production from paper sludge hydrolysate

    NARCIS (Netherlands)

    Kádár, Z.; Vrije, de G.J.; Budde, M.A.W.; Szengyel, Z.; Reczey, K.; Claassen, P.A.M.

    2003-01-01

    The main objective of this study was to develop a system for the production of 'renewable' hydrogen. Paper sludge is a solid industrial waste yielding mainly cellulose, which can be used, after hydrolysis, as a feedstock in anaerobic fermentation by (hyper)thermophilic organisms, such as Thermotoga

  12. Electricity-mediated biological hydrogen production

    NARCIS (Netherlands)

    Geelhoed, J.S.; Hamelers, H.V.M.; Stams, A.J.M.

    2010-01-01

    Anaerobic bacteria have the ability to produce electricity from the oxidation of organic substrates. They also may use electricity to support chemical reactions that are energetically unfavorable. In the fermentation of sugars, hydrogen can be formed as one of the main products. However, a yield of

  13. Catalytic hydrogenation of carbon monoxide. Progress report, December 15, 1991--December 14, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Wayland, B.B.

    1992-12-01

    This project is focused on developing strategies to accomplish the reduction and hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. Our approaches to this issue are based on the recognition that rhodium macrocycles have unusually favorable thermodynamic values for producing a series of intermediate implicated in the catalytic hydrogenation of CO. Observations of metalloformyl complexes produced by reactions of H{sub 2} and CO, and reductive coupling of CO to form metallo {alpha}-diketone species have suggested a multiplicity of routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in constructing energy profiles for a variety of potential pathways, and these schemes are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Variation of the electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Emerging knowledge of the factors that contribute to M-H, M-C and M-O bond enthalpies is directing the search for ligand arrays that will expand the range of metal species that have favorable thermodynamic parameters to produce the primary intermediates for CO hydrogenation. Studies of rhodium complexes are being extended to non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics. Multifunctional catalyst systems designed to couple the ability of rhodium complexes to produce formyl and diketone intermediates with a second catalyst that hydrogenates these imtermediates are promising approaches to accomplish CO hydrogenation at mild conditions.

  14. Catalytic production of aromatics and olefins from plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Haag, W.O.; Rodewald, P.G.; Weisz, P.B.

    1980-08-01

    Hydrocarbons and hydrocarbon-like plant materials offer the possibility of relatively simple and energy-efficient processing to liquid fuels or petrochemicals. The use of such highly reduced photosynthesis products as potential fuels has been advocated by Calvin and coworkers, and Buchanan and coworkers have evaluated several hundred plant species for the presence of hydrocarbons. The yield of extracted oils may exceed 10 wt % of the plant dry weight. Some field growth studies of the most promising of these plants are underway, e.g., by Calvin in California, by Native Plants, Inc., and by the Diamond Shamrock Co., in conjunction with the University of Arizona, mostly with Euphorbia and related genera. Exploratory studies were performed to determine if direct catalytic upgrading of the hydrocarbon-like plant constituents could be carried out. A preliminary report has been published recently. A variety of plant materials were shown to be upgraded to liquid premium fuels by relatively simple catalytic processing over Mobil's shape selective zeolite, ZSM-5. The present paper contains additional information on the conversion of a variety of plant materials with special emphasis on the production of petrochemicals, and discusses key mechanistic aspects of the reactions. Feedstocks were chosen to represent different types of plant materials: corn oil, castor oil and jojoba seed oil; plant extracts from Euphorbia lathyrus and Grindelia squarrosa; and hydrocarbons obtained by tapping of trees such as copaiba oil and natural rubber latex.

  15. Catalytic Hydrodeoxygenation of Fatty Acids for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Аntonina A. Stepacheva

    2016-08-01

    Full Text Available This paper is devoted to the production of second generation biodiesel via catalytic hydrodeoxygenation of fatty acids. Pd/C catalysts with different metal loading were used. The palladium catalysts were characterized using low-temperature nitrogen physisorption and X-ray photoelectron spectroscopy. It was revealed that the most active and selective catalyst was 1%-Pd/C which allowed reaching up 97.5% of selectivity (regarding to n-heptadecane at 100% conversion of substrate. Moreover, the chosen catalyst is more preferable according to lower metal content that leads the decrease of the process cost. The analysis of the catalysts showed that 1%-Pd/C had the highest specific surface area compared with 5%-Pd/C. Copyright © 2016 BCREC GROUP. All rights reserved Received: 31st July 2015; Revised: 9th December 2015; Accepted: 30th December 2015 How to Cite: Stepacheva, A.A., Sapunov, V.N., Sulman, E.M., Nikoshvili, L.Z., Sulman, M.G., Sidorov, A.I., Demidenko, G.N., Matveeva, V.G. (2016. Catalytic Hydrodeoxygenation of Fatty Acids for Biodiesel Production. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2: 125-132 (doi:10.9767/bcrec.11.2.538.125-132 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.538.125-132

  16. Photobiological hydrogen production employing Spirulina Maxima

    Energy Technology Data Exchange (ETDEWEB)

    Ugas, A.J.; Sebastian, P.J. [CIE-UNAM, Morelos (Mexico); Duhakt, R.V.; Valencia, R.T. [IBT-UNAM, Cuernavaca, Morelos (Mexico)

    2003-07-01

    Efforts are being made to develop materials and processes for the renewable production of hydrogen. This paper described the biological production of hydrogen using microorganisms via the photosynthetic route. Several experiments were conducted to produce hydrogen from the biomass of a strain of photosynthetic Spirulina maxim. Conductimetry was used to quantify the results, along with its introduction in a proton exchange membrane (PEM) fuel cell. The current generated was then measured. Spirulina maxim was cultivated under illumination by magnetic agitation air bubbling. The biomass was concentrated by filtration with micro-porous nylon cloth. The algal biomass was quantified by dry weight and by spectrophotometry. The biomass underwent an anaerobic process in darkness, under a nitrogen flow for 30 minutes. The photosynthesis reaction and the production of the enzyme hydrogenase were induced by leaving the culture in agitation and under illumination for 30 minutes to 2 hours. Tests were conducted with and without the addition of 2 grams of sodium ditionite before the photosynthesis process and with the same incident radiation in the bioreactor, which was coupled to a PEM fuel cell. The electric current generated was measured. The results indicate that after a certain stage of cellular growth, Spirulina maxim was capable of producing hydrogen photosynthetically after a process of anaerobic darkness. The biological production of hydrogen was quantifiable by conductimetry and coupling the bioreactor to a PEM fuel cell. The sodium ditionite proved to be a strong reducing agent that inhibits the oxygen production during the photosynthesis process and allows the activation of the enzyme hydrogenase. 4 refs., 2 tabs.

  17. Studies on Hydrogen Selective Silica Membranes and the Catalytic Reforming of CH4 with CO2 in a Membrane Reactor

    OpenAIRE

    Lee, Doohwan

    2003-01-01

    In this work the synthesis, characterization, and gas transport properties of hydrogen selective silica membranes were studied along with the catalytic reforming of CH4 with CO2 (CH4 + CO z 2 CO + 2 H2) in a hydrogen separation membrane reactor. The silica membranes were prepared by chemical vapor deposition (CVD) of a thin SiO2 layer on porous supports (Vycor glass and alumina) using thermal decomposition of tetraethylorthosilicate (TEOS) in an inert atmosphere. These membranes displayed h...

  18. Photosynthetic hydrogen and oxygen production - Kinetic studies

    Science.gov (United States)

    Greenbaum, E.

    1982-01-01

    The simultaneous photoproduction of hydrogen and oxygen was measured in a study of the steady-state turnover times of two biological systems, by driving them into the steady state with repetitive, single-turnover flash illumination. The systems were: (1) in vitro, isolated chloroplasts, ferredoxin and hydrogenase; and (2) the anaerobically-adapted green alga Chlamydomonas reinhardtii. It is found that the turnover times for production of both oxygen and hydrogen in photosynthetic water splitting are in milliseconds, and either equal to, or less than, the turnover time for carbon dioxide reduction in intact algal cells. There is therefore mutual compatibility between hydrogen and oxygen turnover times, and partial compatibility with the excitation rate of the photosynthetic reaction centers under solar irradiation conditions.

  19. Hydrogen Peroxide as a Sustainable Energy Carrier: Electrocatalytic Production of Hydrogen Peroxide and the Fuel Cell

    Science.gov (United States)

    Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D.

    2012-01-01

    This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O2-reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal-oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O2, which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells. PMID:23457415

  20. Hydrogen Peroxide as a Sustainable Energy Carrier: Electrocatalytic Production of Hydrogen Peroxide and the Fuel Cell.

    Science.gov (United States)

    Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D

    2012-11-01

    This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O2-reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal-oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O2, which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells.

  1. Hydrogen peroxide as a sustainable energy carrier: Electrocatalytic production of hydrogen peroxide and the fuel cell

    International Nuclear Information System (INIS)

    This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O2-reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal–oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O2, which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells.

  2. Bio-ethanol steam reforming: Insights on the mechanism for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Benito, M.; Sanz, J.L.; Isabel, R.; Padilla, R.; Daza, L. [Instituto de Catalisis y Petroleoquimica (CSIC), Campus Cantoblanco, 28049 Madrid (Spain); Arjona, R. [Greencell (ABENGOA BIOENERGIA), Av. de la Buhaira 2, 41018 Sevilla (Spain)

    2005-10-10

    New catalysts for hydrogen production by steam reforming of bio-ethanol have been developed. Catalytic tests have been performed at laboratory scale, with the reaction conditions demanded in a real processor: i.e. ethanol and water feed, without a diluent gas. Catalyst ICP0503 has shown high activity and good resistance to carbon deposition. Reaction results show total conversion, high selectivity to hydrogen (70%), CO{sub 2}, CO and CH{sub 4} being the only by-products obtained. The reaction yields 4.25mol of hydrogen by mol of ethanol fed, close to the thermodynamic equilibrium prediction. The temperature influence on the catalytic activity for this catalyst has been studied. Conversion reaches 100% at temperature higher than 600{sup o}C. In the light of reaction results obtained, a reaction mechanism for ethanol steam reforming is proposed. Long-term reaction experiments have been performed in order to study the stability of the catalytic activity. The excellent stability of the catalyst ICP0503 indicates that the reformed stream could be fed directly to a high temperature fuel cell (MCFC, SOFC) without a further purification treatment. These facts suggest that ICP0503 is a good candidate to be implemented in a bio-ethanol processor for hydrogen production to feed a fuel cell. (author)

  3. Catalytic decomposition of methane to COx-free hydrogen and carbon nanotubes over Co–W/MgO catalysts

    Directory of Open Access Journals (Sweden)

    Ahmed E. Awadallah

    2015-09-01

    Full Text Available Bimetallic catalysts containing a series of Co/W at 40/10, 30/20, 20/30 and 10/40 wt% supported on MgO with a total metal content of 50 wt% were prepared and used for the catalytic decomposition of methane to COx-free hydrogen and multi-walled carbon nanotubes (MWCNTs. The solid fresh and exhausted catalysts were characterized structurally and chemically through XRD, TPR, BET, TGA, TEM and Raman spectroscopy. The 40%Co–10%W/MgO catalyst exhibited the highest activity for the production of both hydrogen and MWCNTs. The formation of a large amount of non-interacted Co3O4 species is considered as the main reason for the catalyst superiority in its activity. On the contrary, catalysts formulations of 20%Co–30%W and 10%Co–40%W demonstrated the formation of a large amount of hardly reducible CoWO4 and MgWO4 particles causing lower activity of these catalysts toward methane decomposition as evidenced through the XRD and TPR results.

  4. Advances in solid-catalytic and non-catalytic technologies for biodiesel production

    International Nuclear Information System (INIS)

    Highlights: • The recent technologies for promoting biodiesel synthesis were elucidated. • The design of catalyst consideration of biodiesel production was proposed. • The recent advances and remaining difficulties in biodiesel synthesis were outlined. • The future research trend in biodiesel synthesis was highlighted. - Abstract: The insecure supply of fossil fuel coerces the scientific society to keep a vision to boost investments in the renewable energy sector. Among the many renewable fuels currently available around the world, biodiesel offers an immediate impact in our energy. In fact, a huge interest in related research indicates a promising future for the biodiesel technology. Heterogeneous catalyzed production of biodiesel has emerged as a preferred route as it is environmentally benign needs no water washing and product separation is much easier. The number of well-defined catalyst complexes that are able to catalyze transesterification reactions efficiently has been significantly expanded in recent years. The activity of catalysts, specifically in application to solid acid/base catalyst in transesterification reaction depends on their structure, strength of basicity/acidity, surface area as well as the stability of catalyst. There are various process intensification technologies based on the use of alternate energy sources such as ultrasound and microwave. The latest advances in research and development related to biodiesel production is represented by non-catalytic supercritical method and focussed exclusively on these processes as forthcoming transesterification processes. The latest developments in this field featuring highly active catalyst complexes are outlined in this review. The knowledge of more extensive research on advances in biofuels will allow a deeper insight into the mechanism of these technologies toward meeting the critical energy challenges in future

  5. Hydrogen production experiments by the thermochemical and electrolytic hybrid hydrogen production process

    International Nuclear Information System (INIS)

    Hydrogen production demonstration experiments from water by the thermochemical and electrolytic hybrid hydrogen production process were performed. The feasibility of this hydrogen production process was demonstrated and technical problems to operate longer duration and to develop 1Nl/h-H2 production experimental apparatus were extracted. (1) Continuous and stable hydrogen and oxygen generation by the hybrid process was measured in the four full process experiments and maximum test duration was about five hours. The generation rate of hydrogen and oxygen calculated from measured current in four full process experiments were 4.03 ml/h-5.04 ml/h and 2.07 ml/h - 2.78 ml/h, respectively. The total amounts of generated hydrogen and oxygen in the four experiments were 35.00 ml and 20.99 ml. (2) Severe material corrosion was not observed for gold plated stainless steel and SO3 electrolysis cell (YSZ, Pt paste electrode) which used in sulfuric acid atmosphere at about 550 deg-C, and ionic oxygen conductivity of YSZ did not decrease in the experiments. Nevertheless, corrosion of the gold plated outlet piping of SO3 electrolysis cell was observed, and the corrosion by condensed sulfuric acid as suspected. (3) Technical problems to operate the present experimental apparatus for 100 hours and to develop test apparatus to generate 1Nl/h hydrogen, were extracted. (author)

  6. Assessment of biological Hydrogen production processes: A review

    Science.gov (United States)

    Najafpour, G. D.; Shahavi, M. H.; Neshat, S. A.

    2016-06-01

    Energy crisis created a special attention on renewable energy sources. Among these sources; hydrogen through biological processes is well-known as the most suitable and renewable energy sources. In terms of process yield, hydrogen production from various sources was evaluated. A summary of microorganisms as potential hydrogen producers discussed along with advantages and disadvantages of several bioprocesses. The pathway of photo-synthetic and dark fermentative organisms was discussed. In fact, the active enzymes involved in performance of biological processes for hydrogen generation were identified and their special functionalities were discussed. The influential factors affecting on hydrogen production were known as enzymes assisting liberation specific enzymes such as nitrogenase, hydrogenase and uptake hydrogenase. These enzymes were quite effective in reduction of proton and form active molecular hydrogen. Several types of photosynthetic systems were evaluated with intension of maximum hydrogen productivities. In addition dark fermentative and light intensities on hydrogen productions were evaluated. The hydrogen productivities of efficient hydrogen producing strains were evaluated.

  7. Wax: A benign hydrogen-storage material that rapidly releases H2-rich gases through microwave-assisted catalytic decomposition

    Science.gov (United States)

    Gonzalez-Cortes, S.; Slocombe, D. R.; Xiao, T.; Aldawsari, A.; Yao, B.; Kuznetsov, V. L.; Liberti, E.; Kirkland, A. I.; Alkinani, M. S.; Al-Megren, H. A.; Thomas, J. M.; Edwards, P. P.

    2016-01-01

    Hydrogen is often described as the fuel of the future, especially for application in hydrogen powered fuel-cell vehicles (HFCV’s). However, its widespread implementation in this role has been thwarted by the lack of a lightweight, safe, on-board hydrogen storage material. Here we show that benign, readily-available hydrocarbon wax is capable of rapidly releasing large amounts of hydrogen through microwave-assisted catalytic decomposition. This discovery offers a new material and system for safe and efficient hydrogen storage and could facilitate its application in a HFCV. Importantly, hydrogen storage materials made of wax can be manufactured through completely sustainable processes utilizing biomass or other renewable feedstocks. PMID:27759014

  8. Ab initio molecular dynamics simulations for the role of hydrogen in catalytic reactions of furfural on Pd(111)

    Science.gov (United States)

    Xue, Wenhua; Dang, Hongli; Liu, Yingdi; Jentoft, Friederike; Resasco, Daniel; Wang, Sanwu

    2014-03-01

    In the study of catalytic reactions of biomass, furfural conversion over metal catalysts with the presence of hydrogen has attracted wide attention. We report ab initio molecular dynamics simulations for furfural and hydrogen on the Pd(111) surface at finite temperatures. The simulations demonstrate that the presence of hydrogen is important in promoting furfural conversion. In particular, hydrogen molecules dissociate rapidly on the Pd(111) surface. As a result of such dissociation, atomic hydrogen participates in the reactions with furfural. The simulations also provide detailed information about the possible reactions of hydrogen with furfural. Supported by DOE (DE-SC0004600). This research used the supercomputer resources of the XSEDE, the NERSC Center, and the Tandy Supercomputing Center.

  9. Detection of hydrogen peroxide in Photosystem II (PSII using catalytic amperometric biosensor

    Directory of Open Access Journals (Sweden)

    Ankush ePrasad

    2015-10-01

    Full Text Available Hydrogen peroxide (H2O2 is known to be generated in Photosystem II (PSII via enzymatic and non-enzymatic pathways. Hydrogen peroxide (H2O2 is known to be generated in Photosystem II (PSII via enzymatic and non-enzymatic pathways. Detection of H2O2 by different spectroscopic techniques has been explored, however its sensitive detection has always been a challenge in photosynthetic research. During the recent past, fluorescence probes such as Amplex Red has been used but is known to either lack specificity or limitation with respect to the minimum detection limit of H2O2. We have employed an electrochemical biosensor for real time monitoring of H2O2 generation at the level of sub-cellular organelles. The electrochemical biosensor comprises of counter electrode and working electrodes. The counter electrode is a platinum plate, while the working electrode is a mediator based catalytic amperometric biosensor device developed by the coating of a carbon electrode with osmium-horseradish peroxidase which acts as H2O2 detection sensor. In the current study, generation and kinetic behaviour of H2O2 in PSII membranes have been studied under light illumination. Electrochemical detection of H2O2 using the catalytic amperometric biosensor device is claimed to serve as a promising technique for detection of H2O2 in photosynthetic cells and subcellular structures including PSII or thylakoid membranes. It can also provide a precise information on qualitative determination of H2O2 and thus can be widely used in photosynthetic research.

  10. Thermochemical hydrogen production based on magnetic fusion

    International Nuclear Information System (INIS)

    Conceptual design studies have been carried out on an integrated fusion/chemical plant system using a Tandem Mirror Reactor fusion energy source to drive the General Atomic Sulfur-Iodine Water-Splitting Cycle and produce hydrogen as a future feedstock for synthetic fuels. Blanket design studies for the Tandem Mirror Reactor show that several design alternatives are available for providing heat at sufficiently high temperatures to drive the General Atomic Cycle. The concept of a Joule-boosted decomposer is introduced in one of the systems investigated to provide heat electrically for the highest temperature step in the cycle (the SO3 decomposition step), and thus lower blanket design requirements and costs. Flowsheeting and conceptual process designs have been developed for a complete fusion-driven hydrogen plant, and the information has been used to develop a plot plan for the plant and to estimate hydrogen production costs. Both public and private utility financing approaches have been used to obtain hydrogen production costs of $12-14/GJ based on July 1980 dollars

  11. High performing and stable supported nano-alloys for the catalytic hydrogenation of levulinic acid to gamma-valerolactone

    NARCIS (Netherlands)

    Luo, Wenhao; Meenakshisundaram, Sankar; Beale, Andrew M.; He, Qian; Kiely, Christopher J.; Bruijnincx, Pieter C. A.; Weckhuysen, Bert M.

    2015-01-01

    The catalytic hydrogenation of levulinic acid, a key platform molecule in many biorefinery schemes, into gamma-valerolactone is considered as one of the pivotal reactions to convert lignocellulose-based biomass into renewable fuels and chemicals. Here we report on the development of highly active, s

  12. SYNTHESIS OF POLYMER-STABILIZED PLATINUM/RUTHENIUM BIMETALLIC COLLOIDS AND THEIR CATALYTIC PROPERTIES FOR SELECTIVE HYDROGENATION OF CROTONALDEHYDE

    Institute of Scientific and Technical Information of China (English)

    Wei-xia Tu; Han-fan Liu

    2005-01-01

    Polymer-stabilized platinum/ruthenium bimetallic colloids (Pt/Ru) were synthesized by polyol reduction with microwave irradiation and characterized by TEM and XPS. The colloidal nanoparticles have small and narrow size distributions. Catalytic performance of the Pt/Ru colloidal catalysts was investigated on the selective hydrogenation of crontonaldehyde (CRAL). A suitable amount of the added metal ions and base can improve the selectivity of CRAL to crotylalcohol (CROL) remarkably. The catalytic activity and the selectivity are dependent on the compositions of bimetallic colloids. Thereinto, PVP-stabilized 9Pt/1Ru colloid with a molar ratio of metals Pt:Ru = 9:1 shows the highest catalytic selectivity 77.3% to CROL at 333 K under 4.0 MPa of hydrogen.

  13. Hydrogenated liquids and hydrogen production by non-thermal plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Arabi, K.; Aubry, O.; Khacef, A.; Cormier, J.M. [Orleans Univ., Orleans Cedex (France). Centre national de la recherche scientifique, Polytech d' Orleans, Group for Research and Studies on Mediators of Inflamation

    2010-07-01

    In recent years, hydrogen (H{sub 2}) has been considered as a fuel for electricity generation and transportation purposes. H{sub 2} is a renewable energy source that does not contribute to the greenhouse effect. This paper reported on a comparative study of syngas production from alcohol, with particular reference to the plasma steam-reforming of ethanol, methanol, ammonia and vegetable oil. The H{sub 2} yields and energetic cost in function of hydrogen sources were presented. The non thermal plasma used in this study was a laboratory scale experimental device static discharge. An arc formed between two electrodes made of graphite. The efficiency of the process was determined through chemical diagnostics. Gas chromatography and Fourier transform infrared (FTIR) techniques were used to determine concentrations of H{sub 2}, carbon monoxide, carbon dioxide and carbon as functions of flow and inlet liquid mixture concentration parameters. This paper also presented the values of H{sub 2}/CO ratio and the composition of synthesis gas according to various operating conditions. 18 refs., 2 tabs., 8 figs.

  14. Photochemical Production of Hydrogen from Water

    International Nuclear Information System (INIS)

    The energy flux in sunlight is 40 000 kW per head of the world population. Theoretically much of this energy can be used to photolyze water, in presence of a sensitizer, to H2 (and 02) for a hydrogen economy. The main difficulty in a homogeneous medium is the back-reaction of the primary products. According to the 'membrane principle', the reducing and the oxidizing primary products are released on opposite sides of asymmetric membranes, and so prevented from back-reacting. In essence, this is the mechanism of the photosynthetic machinery in plants and bacteria. This therefore serves as an example in the artificial construction of suitable asymmetric, 'vectorial', membranes. Relatively small areas of photolytic collectors, e.g. in tropical deserts, could cover the energy needs of large populations through hydrogen. (author)

  15. Startech Hydrogen Production Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Startech Engineering Department

    2007-11-27

    The assigned work scope includes the modification and utilization of the Plasma Converter System, Integration of a StarCell{trademark} Multistage Ceramic Membrane System (StarCell), and testing of the integrated systems towards DOE targets for gasification and membrane separation. Testing and evaluation was performed at the Startech Engineering and Demonstration Test Center in Bristol, CT. The Objectives of the program are as follows: (1) Characterize the performance of the integrated Plasma Converter and StarCell{trademark} Systems for hydrogen production and purification from abundant and inexpensive feedstocks; (2) Compare integrated hydrogen production performance to conventional technologies and DOE benchmarks; (3) Run pressure and temperature testing to baseline StarCell's performance; and (4) Determine the effect of process contaminants on the StarCell{trademark} system.

  16. Novel Fast Pyrolysis/Catalytic Technology for the Production of Stable Upgraded Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Ted; Agblevor, Foster; Battaglia, Francine; Klein, Michael

    2013-01-18

    The objective of the proposed research is the demonstration and development of a novel biomass pyrolysis technology for the production of a stable bio-oil. The approach is to carry out catalytic hydrodeoxygenation (HDO) and upgrading together with pyrolysis in a single fluidized bed reactor with a unique two-level design that permits the physical separation of the two processes. The hydrogen required for the HDO will be generated in the catalytic section by the water-gas shift reaction employing recycled CO produced from the pyrolysis reaction itself. Thus, the use of a reactive recycle stream is another innovation in this technology. The catalysts will be designed in collaboration with BASF Catalysts LLC (formerly Engelhard Corporation), a leader in the manufacture of attrition-resistant cracking catalysts. The proposed work will include reactor modeling with state-of-the-art computational fluid dynamics in a supercomputer, and advanced kinetic analysis for optimization of bio-oil production. The stability of the bio-oil will be determined by viscosity, oxygen content, and acidity determinations in real and accelerated measurements. A multi-faceted team has been assembled to handle laboratory demonstration studies and computational analysis for optimization and scaleup.

  17. Photobiological hydrogen production and carbon dioxide sequestration

    Science.gov (United States)

    Berberoglu, Halil

    Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the radiation characteristics of hydrogen producing and carbon dioxide consuming microorganisms, (2) solar radiation transfer modeling and simulation in photobioreactors, and (3) parametric experiments of photobiological hydrogen production and carbon dioxide sequestration. First, solar radiation transfer in photobioreactors containing microorganisms and bubbles was modeled using the radiative transport equation (RTE) and solved using the modified method of characteristics. The study concluded that Beer-Lambert's law gives inaccurate results and anisotropic scattering must be accounted for to predict the local irradiance inside a photobioreactor. The need for accurate measurement of the complete set of radiation characteristics of microorganisms was established. Then, experimental setup and analysis methods for measuring the complete set of radiation characteristics of microorganisms have been developed and successfully validated experimentally. A database of the radiation characteristics of representative microorganisms have been created including the cyanobacteria Anabaena variabilis, the purple non-sulfur bacteria Rhodobacter sphaeroides and the green algae Chlamydomonas reinhardtii along with its three genetically engineered strains. This enabled, for the first time, quantitative assessment of the effect of genetic engineering on the radiation characteristics of microorganisms. In addition, a parametric experimental study has been performed to model the growth, CO2 consumption, and H 2 production of Anabaena variabilis as functions of

  18. An FTIR study on the catalytic effect of water molecules on the reaction of CO successive hydrogenation at 3 K

    International Nuclear Information System (INIS)

    Graphical abstract: This work highlights a selective catalytic action of water molecules on the reaction of CO hydrogenation at 3 K. Research highlights: → [CO/H2O] and [H/H2] are coinjected at 3 K. → H2 molecules condense rapidly at 3 K and screen the reaction mostly at the 1st step. → The observed catalytic effects on CO hydrogenation increase with water concentration. - Abstract: The reaction of successive CO hydrogenation has been performed at 3 K by coinjecting CO molecules and H atoms. The concentration of CO has been progressively reduced and replaced by water molecules to create two different environments where CO and H2O are successively the dominant species in the binary (CO/H2O) mixture. The catalytic effect of water molecules on CO hydrogenation appears clearly since the early times of the experiment and evolves with the formation of the CO/H2/H2O mixed-matrix. The process of CO hydrogenation, initially frozen at the first step of the reaction, is brought to completion through water influence. Water molecules guide the reaction toward the formation of CH3OH and promote different reaction steps depending on water concentration. Water molecules increase the probability of reactive to encounter H atoms either physically, by introducing structural changes in the matrix, or chemically, by raising the number of chemical pathways.

  19. Microbial electrolysis cells as innovative technology for hydrogen production

    International Nuclear Information System (INIS)

    Hydrogen production is becoming increasingly important in view of using hydrogen in fuel cells. However, most of the production of hydrogen so far comes from the combustion of fossil fuels and water electrolysis. Microbial Electrolysis Cell (MEC), also known as Bioelectrochemically Assisted Microbial Reactor, is an ecologically clean, renewable and innovative technology for hydrogen production. Microbial electrolysis cells produce hydrogen mainly from waste biomass assisted by various bacteria strains. The principle of MECs and their constructional elements are reviewed and discussed. Keywords: microbial Electrolysis Cells, hydrogen production, waste biomass purification

  20. Hydrogen production by thermal water splitting using ferroelectric PbTiO3

    Science.gov (United States)

    Kakekhani, Arvin; Ismail-Beigi, Sohrab

    The increasing demand for renewable energy sources is a prominent challenge facing humanity in 21st century. In this regard, hydrogen production by splitting water has received great attention. Here, we theoretically propose a catalytic cycle that by leveraging the pyroelectric properties of ferroelectric PbTiO3, and using a controlled temperature modulation around Curie temperature as a switch for surface chemical properties, can thermally split H2O into O2 and H2. Since the Curie temperature of PbZrxTi1-xO3 class of materials is tunable and usually in the range of 250-450 degree Celsius; the energy needed to drive this catalytic cycle can be provided by low/intermediate grade heat, for instance: geothermal, industrial waste heat or concentrated solar power. Since no precious metal is needed in this scheme, and all the elements are earth abundant, this can potentially become an economically viable method for hydrogen production.

  1. Hydrogen Production from Methanol Using Corona Discharges

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Hydrogen production at room temperature from liquid methanol has been conductedusing corona discharge. The content of water in methanol solution has a significant effect on thisproduction. When water concentration increases from 1.0 % to 16.7 %, the methanol conversionrate changes from 0.196 to 0.284 mol/h. An important finding in this investigation is theformation of ethylene glycol as a major by-product. The yield of ethylene glycol is ranged from0.0045 to 0.0075 mol/h based on the water content.

  2. Production economics for hydrogen, ammonia, and methanol during the 1980--2000 period

    Energy Technology Data Exchange (ETDEWEB)

    Corneil, H G; Heinzelmann, F J; Nicholson, E W.S.

    1977-04-01

    Refinery hydrogen, ammonia, and methanol, the principal industrial hydrogen products, are now manufactured mainly by catalytic steam reforming of natural gas or some alternative light-hydrocarbon feed stock. Anticipated increases in the prices of hydrocarbons are expected to exceed those for coal, thus gradually increasing the incentive to use coal gasification as a source of industrial hydrogen during the 1980 to 2000 period. Although the investment in industrial hydrogen plants will exceed those for reforming by a factor of 2 or more, coal gasification will provide lower production costs (including 20%/y before tax return) for methanol manufacture in the early 1980's and for ammonia 5 years or so later. However, high costs for transporting coal to major refining centers will make it difficult to justify coal gasification for refinery hydrogen production during the 1980 to 2000 period. By the year 2000, 40 to 50% of the U.S. industrial hydrogen requirements will be provided by coal gasification thus conserving natural gas and light hydrocarbon feed stocks equivalent to about 600,000 B/D of crude oil. Electrolytic hydrogen production costs will be reduced by improved electrolysis technology such as the solid-polymer-electrolyte process. These improved processes will reduce electrolysis plant investments by a factor of 2 or more and reduce electricity requirements by about 20%. Although the production cost, including return for electrolytic hydrogen, will continue to exceed those for reforming and coal gasification, the use of electrolytic hydrogen will be attractive for many small users when the new technology is available in the early 1980's. Electrolytic hydrogen now about 0.7% of total U.S. industrial hydrogen requirements will probably increase to about 1.2% of the total by the year 2000.

  3. Preliminary Hydrogen Production Cost Estimation based on the HEEP

    International Nuclear Information System (INIS)

    The HEEP software is appropriate to perform economic analysis for comparative studies not only hydrogen production using nuclear or fossil fuel but also only hydrogen production or cogeneration with electricity. The HEEP software requires basic input data to calculate hydrogen production cost such as chronological data, finance data, and technical data related to nuclear power plant and hydrogen generation plant. In this paper, we present preliminary hydrogen production cost estimation based on the HEEP. In order to get more concrete and accurate cost calculations, we need to consider many parameters and input values in details including hydrogen storage cost and hydrogen transportation cost. The estimated costs presented in this paper show that hydrogen production by VHTR coupled to SI plant system could be competitive with current techniques of hydrogen production from fossil fuels if CO2 capture and sequestration is required. This favorable situation is expected to further improve as the cost of natural gas rises. Nuclear hydrogen production would allow large-scale production of hydrogen at economic prices while avoiding the release of CO2. Nuclear production of hydrogen could thus become the enabling technology for the hydrogen economy

  4. Integrated Ceramic Membrane System for Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Joseph; Lim, Hankwon; Drnevich, Raymond

    2010-08-05

    Phase I was a technoeconomic feasibility study that defined the process scheme for the integrated ceramic membrane system for hydrogen production and determined the plan for Phase II. The hydrogen production system is comprised of an oxygen transport membrane (OTM) and a hydrogen transport membrane (HTM). Two process options were evaluated: 1) Integrated OTM-HTM reactor – in this configuration, the HTM was a ceramic proton conductor operating at temperatures up to 900°C, and 2) Sequential OTM and HTM reactors – in this configuration, the HTM was assumed to be a Pd alloy operating at less than 600°C. The analysis suggested that there are no technical issues related to either system that cannot be managed. The process with the sequential reactors was found to be more efficient, less expensive, and more likely to be commercialized in a shorter time than the single reactor. Therefore, Phase II focused on the sequential reactor system, specifically, the second stage, or the HTM portion. Work on the OTM portion was conducted in a separate program. Phase IIA began in February 2003. Candidate substrate materials and alloys were identified and porous ceramic tubes were produced and coated with Pd. Much effort was made to develop porous substrates with reasonable pore sizes suitable for Pd alloy coating. The second generation of tubes showed some improvement in pore size control, but this was not enough to get a viable membrane. Further improvements were made to the porous ceramic tube manufacturing process. When a support tube was successfully coated, the membrane was tested to determine the hydrogen flux. The results from all these tests were used to update the technoeconomic analysis from Phase I to confirm that the sequential membrane reactor system can potentially be a low-cost hydrogen supply option when using an existing membrane on a larger scale. Phase IIB began in October 2004 and focused on demonstrating an integrated HTM/water gas shift (WGS) reactor to

  5. A Technical and Economic Review of Solar Hydrogen Production Technologies

    Science.gov (United States)

    Wilhelm, Erik; Fowler, Michael

    2006-01-01

    Hydrogen energy systems are being developed to replace fossil fuels-based systems for transportation and stationary application. One of the challenges facing the widespread adoption of hydrogen as an energy vector is the lack of an efficient, economical, and sustainable method of hydrogen production. In the short term, hydrogen produced from…

  6. Steam reforming of sunflower oil for hydrogen gas production

    OpenAIRE

    Dupont V.

    2007-01-01

    Methods of current hydrogen production for the petroleum refinery industry as well as future technologies under research and development in preparation for a global hydrogen-based economy are briefly reviewed. The advantages of biomass and of liquid biofuels, including vegetable oils as fuel sources in the sustainable production of hydrogen gas are then presented. The bulk of this lecture is thereafter concerned with the thermo-chemical means of hydrogen production which are suitable to the c...

  7. Production of Low-carbon Light Olefins from Catalytic Cracking of Crude Bio-oil

    Institute of Scientific and Technical Information of China (English)

    Yan-ni Yuan; Tie-jun Wang; Quan-xin Li

    2013-01-01

    Low-carbon light olefins are the basic feedstocks for the petrochemical industry.Catalytic cracking of crude bio-oil and its model compounds (including methanol,ethanol,acetic acid,acetone,and phenol) to light olefins were performed by using the La/HZSM-5 catalyst.The highest olefins yield from crude bio-oil reached 0.19 kg/(kg crude bio-oil).The reaction conditions including temperature,weight hourly space velocity,and addition of La into the HZSM-5 zeolite can be used to control both olefins yield and selectivity.Moderate adjusting the acidity with a suitable ratio between the strong acid and weak acid sites through adding La to the zeolite effectively enhanced the olefins selectivity and improved the catalyst stability.The production of light olefins from crude bio-oil is closely associated with the chemical composition and hydrogen to carbon effective ratios of feedstock.The comparison between the catalytic cracking and pyrolysis of bio-oil was studied.The mechanism of the bio-oil conversion to light olefins was also discussed.

  8. Hydrogenation-controlled phase transition on two-dimensional transition metal dichalcogenides and their unique physical and catalytic properties

    Science.gov (United States)

    Qu, Yuanju; Pan, Hui; Kwok, Chi Tat

    2016-09-01

    Two-dimensional (2D) transition metal dichalcogenides (TMDs) have been widely used from nanodevices to energy harvesting/storage because of their tunable physical and chemical properties. In this work, we systematically investigate the effects of hydrogenation on the structural, electronic, magnetic, and catalytic properties of 33 TMDs based on first-principles calculations. We find that the stable phases of TMD monolayers can transit from 1T to 2H phase or vice versa upon the hydrogenation. We show that the hydrogenation can switch their magnetic and electronic states accompanying with the phase transition. The hydrogenation can tune the magnetic states of TMDs among non-, ferro, para-, and antiferro-magnetism and their electronic states among semiconductor, metal, and half-metal. We further show that, out of 33 TMD monolayers, 2H-TiS2 has impressive catalytic ability comparable to Pt in hydrogen evolution reaction in a wide range of hydrogen coverages. Our findings would shed the light on the multi-functional applications of TMDs.

  9. Hydrogenation-controlled phase transition on two-dimensional transition metal dichalcogenides and their unique physical and catalytic properties

    Science.gov (United States)

    Qu, Yuanju; Pan, Hui; Kwok, Chi Tat

    2016-01-01

    Two-dimensional (2D) transition metal dichalcogenides (TMDs) have been widely used from nanodevices to energy harvesting/storage because of their tunable physical and chemical properties. In this work, we systematically investigate the effects of hydrogenation on the structural, electronic, magnetic, and catalytic properties of 33 TMDs based on first-principles calculations. We find that the stable phases of TMD monolayers can transit from 1T to 2H phase or vice versa upon the hydrogenation. We show that the hydrogenation can switch their magnetic and electronic states accompanying with the phase transition. The hydrogenation can tune the magnetic states of TMDs among non-, ferro, para-, and antiferro-magnetism and their electronic states among semiconductor, metal, and half-metal. We further show that, out of 33 TMD monolayers, 2H-TiS2 has impressive catalytic ability comparable to Pt in hydrogen evolution reaction in a wide range of hydrogen coverages. Our findings would shed the light on the multi-functional applications of TMDs. PMID:27686869

  10. Field-controlled electron transfer and reaction kinetics of the biological catalytic system of microperoxidase-11 and hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Yongki Choi

    2011-12-01

    Full Text Available Controlled reaction kinetics of the bio-catalytic system of microperoxidase-11 and hydrogen peroxide has been achieved using an electrostatic technique. The technique allowed independent control of 1 the thermodynamics of the system using electrochemical setup and 2 the quantum mechanical tunneling at the interface between microperoxidase-11 and the working electrode by applying a gating voltage to the electrode. The cathodic currents of electrodes immobilized with microperoxidase-11 showed a dependence on the gating voltage in the presence of hydrogen peroxide, indicating a controllable reduction reaction. The measured kinetic parameters of the bio-catalytic reduction showed nonlinear dependences on the gating voltage as the result of modified interfacial electron tunnel due to the field induced at the microperoxidase-11-electrode interface. Our results indicate that the kinetics of the reduction of hydrogen peroxide can be controlled by a gating voltage and illustrate the operation of a field-effect bio-catalytic transistor, whose current-generating mechanism is the conversion of hydrogen peroxide to water with the current being controlled by the gating voltage.

  11. Resource Assessment for Hydrogen Production: Hydrogen Production Potential from Fossil and Renewable Energy Resources

    Energy Technology Data Exchange (ETDEWEB)

    Melaina, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Penev, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Heimiller, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-09-01

    This study examines the energy resources required to produce 4-10 million metric tonnes of domestic, low-carbon hydrogen in order to fuel approximately 20-50 million fuel cell electric vehicles. These projected energy resource requirements are compared to current consumption levels, projected 2040 business as usual consumptions levels, and projected 2040 consumption levels within a carbonconstrained future for the following energy resources: coal (assuming carbon capture and storage), natural gas, nuclear (uranium), biomass, wind (on- and offshore), and solar (photovoltaics and concentrating solar power). The analysis framework builds upon previous analysis results estimating hydrogen production potentials and drawing comparisons with economy-wide resource production projections

  12. Catalytic water co-existing with a product peptide in the active site of HIV-1 protease revealed by X-ray structure analysis.

    Directory of Open Access Journals (Sweden)

    Vishal Prashar

    Full Text Available BACKGROUND: It is known that HIV-1 protease is an important target for design of antiviral compounds in the treatment of Acquired Immuno Deficiency Syndrome (AIDS. In this context, understanding the catalytic mechanism of the enzyme is of crucial importance as transition state structure directs inhibitor design. Most mechanistic proposals invoke nucleophilic attack on the scissile peptide bond by a water molecule. But such a water molecule coexisting with any ligand in the active site has not been found so far in the crystal structures. PRINCIPAL FINDINGS: We report here the first observation of the coexistence in the active site, of a water molecule WAT1, along with the carboxyl terminal product (Q product peptide. The product peptide has been generated in situ through cleavage of the full-length substrate. The N-terminal product (P product has diffused out and is replaced by a set of water molecules while the Q product is still held in the active site through hydrogen bonds. The position of WAT1, which hydrogen bonds to both the catalytic aspartates, is different from when there is no substrate bound in the active site. We propose WAT1 to be the position from where catalytic water attacks the scissile peptide bond. Comparison of structures of HIV-1 protease complexed with the same oligopeptide substrate, but at pH 2.0 and at pH 7.0 shows interesting changes in the conformation and hydrogen bonding interactions from the catalytic aspartates. CONCLUSIONS/SIGNIFICANCE: The structure is suggestive of the repositioning, during substrate binding, of the catalytic water for activation and subsequent nucleophilic attack. The structure could be a snap shot of the enzyme active site primed for the next round of catalysis. This structure further suggests that to achieve the goal of designing inhibitors mimicking the transition-state, the hydrogen-bonding pattern between WAT1 and the enzyme should be replicated.

  13. Storage and production of hydrogen for fuel cell applications

    Science.gov (United States)

    Aiello, Rita

    The increased utilization of proton-exchange membrane (PEM) fuel cells as an alternative to internal combustion engines is expected to increase the demand for hydrogen, which is used as the energy source in these systems. The objective of this work is to develop and test new methods for the storage and production of hydrogen for fuel cells. Six ligand-stabilized hydrides were synthesized and tested as hydrogen storage media for use in portable fuel cells. These novel compounds are more stable than classical hydrides (e.g., NaBH4, LiAlH4) and react to release hydrogen less exothermically upon hydrolysis with water. Three of the compounds produced hydrogen in high yield (88 to 100 percent of the theoretical) and at significantly lower temperatures than those required for the hydrolysis of NaBH4 and LiAlH4. However, a large excess of water and acid were required to completely wet the hydride and keep the pH of the reaction medium neutral. The hydrolysis of the classical hydrides with steam can overcome these limitations. This reaction was studied in a flow reactor and the results indicate that classical hydrides can be hydrolyzed with steam in high yields at low temperatures (110 to 123°C) and in the absence of acid. Although excess steam was required, the pH of the condensed steam was neutral. Consequently, steam could be recycled back to the reactor. Production of hydrogen for large-scale transportation fuel cells is primarily achieved via the steam reforming, partial oxidation or autothermal reforming of natural gas or the steam reforming of methanol. However, in all of these processes CO is a by-product that must be subsequently removed because the Pt-based electrocatalyst used in the fuel cells is poisoned by its presence. The direct cracking of methane over a Ni/SiO2 catalyst can produce CO-free hydrogen. In addition to hydrogen, filamentous carbon is also produced. This material accumulates on the catalyst and eventually deactivates it. The Ni/SiO2 catalyst

  14. Production of hydrogen from municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, S.L.

    1995-11-01

    The Gasification of Municipal Solid Waste (MSW) includes gasification and the process for producing a gasificable slurry from raw MSW by using high pressures of steam. A potential energy source, MSW is a composite of organic materials such as: paper, wood, food waste, etc. There are different paper grades producing different results with low-quality paper forming better slurries than high-quality papers; making MSW a difficult feedstock for gasification. The objective of the bench-scale laboratory work has been to establish operating conditions for a hydrothermal pre-processing scheme for municipal solid waste (MSW) that produces a good slurry product that can be pumped and atomized to the gasifier for the production of hydrogen. Batch reactors are used to determine product yields as a function of hydrothermal treatment conditions. Various ratios of water-to-paper were used to find out solid product, gas product, and soluble product yields of MSW. Experimental conditions covered were temperature, time, and water to feed ratio. Temperature had the strongest effect on product yields.

  15. Hydrogen Production in the U.S. and Worldwide - 2013

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Daryl R.

    2015-04-01

    This article describes the different categories of hydrogen production (captive, by-product, and merchant) and presents production data for 2013 by industry within these categories. Merchant production data is provided for the top-four industrial gas companies.

  16. Plasma processing methods for hydrogen production

    Science.gov (United States)

    Mizeraczyk, Jerzy; Jasiński, Mariusz

    2016-08-01

    In the future a transfer from the fossil fuel-based economy to hydrogen-based economy is expected. Therefore the development of systems for efficient H2 production becomes important. The several conventional methods of mass-scale (or central) H2 production (methane, natural gas and higher hydrocarbons reforming, coal gasification reforming) are well developed and their costs of H2 production are acceptable. However, due to the H2 transport and storage problems the small-scale (distributed) technologies for H2 production are demanded. However, these new technologies have to meet the requirement of producing H2 at a production cost of (1-2)/kg(H2) (or 60 g(H2)/kWh) by 2020 (the U.S. Department of Energy's target). Recently several plasma methods have been proposed for the small-scale H2 production. The most promising plasmas for this purpose seems to be those generated by gliding, plasmatron and nozzle arcs, and microwave discharges. In this paper plasma methods proposed for H2 production are briefly described and critically evaluated from the view point of H2 production efficiency. The paper is aiming at answering a question if any plasma method for the small-scale H2 production approaches such challenges as the production energy yield of 60 g(H2)/kWh, high production rate, high reliability and low investment cost. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  17. Catalytic Transfer Hydrogenation of Furfural to Furfuryl Alcohol over Nitrogen-Doped Carbon-Supported Iron Catalysts.

    Science.gov (United States)

    Li, Jiang; Liu, Jun-Ling; Zhou, Hong-Jun; Fu, Yao

    2016-06-01

    Iron-based heterogeneous catalysts, which were generally prepared by pyrolysis of iron complexes on supports at elevated temperature, were found to be capable of catalyzing the transfer hydrogenation of furfural (FF) to furfuryl alcohol (FFA). The effects of metal precursor, nitrogen precursor, pyrolysis temperature, and support on catalytic performance were examined thoroughly, and a comprehensive study of the reaction parameters was also performed. The highest selectivity of FFA reached 83.0 % with a FF conversion of 91.6 % under the optimal reaction condition. Catalyst characterization suggested that iron cations coordinated by pyridinic nitrogen functionalities were responsible for the enhanced catalytic activity. The iron catalyst could be recycled without significant loss of catalytic activity for five runs, and the destruction of the nitrogen-iron species, the presence of crystallized Fe2 O3 phase, and the pore structure change were the main reasons for catalyst deactivation. PMID:27144965

  18. Biological hydrogen production using a membrane bioreactor.

    Science.gov (United States)

    Oh, Sang-Eun; Iyer, Prabha; Bruns, Mary Ann; Logan, Bruce E

    2004-07-01

    A cross-flow membrane was coupled to a chemostat to create an anaerobic membrane bioreactor (MBR) for biological hydrogen production. The reactor was fed glucose (10,000 mg/L) and inoculated with a soil inoculum heat-treated to kill non-spore-forming methanogens. Hydrogen gas was consistently produced at a concentration of 57-60% in the headspace under all conditions. When operated in chemostat mode (no flow through the membrane) at a hydraulic retention time (HRT) of 3.3 h, 90% of the glucose was removed, producing 2200 mg/L of cells and 500 mL/h of biogas. When operated in MBR mode, the solids retention time (SRT) was increased to SRT = 12 h producing a solids concentration in the reactor of 5800 mg/L. This SRT increased the overall glucose utilization (98%), the biogas production rate (640 mL/h), and the conversion efficiency of glucose-to-hydrogen from 22% (no MBR) to 25% (based on a maximum of 4 mol-H(2)/mol-glucose). When the SRT was increased from 5 h to 48 h, glucose utilization (99%) and biomass concentrations (8,800 +/- 600 mg/L) both increased. However, the biogas production decreased (310 +/- 40 mL/h) and the glucose-to-hydrogen conversion efficiency decreased from 37 +/- 4% to 18 +/- 3%. Sustained permeate flows through the membrane were in the range of 57 to 60 L/m(2) h for three different membrane pore sizes (0.3, 0.5, and 0.8 microm). Most (93.7% to 99.3%) of the membrane resistance was due to internal fouling and the reversible cake resistance, and not the membrane itself. Regular backpulsing was essential for maintaining permeate flux through the membrane. Analysis of DNA sequences using ribosomal intergenic spacer analysis indicated bacteria were most closely related to members of Clostridiaceae and Flexibacteraceae, including Clostridium acidisoli CAC237756 (97%), Linmingia china AF481148 (97%), and Cytophaga sp. MDA2507 AF238333 (99%). No PCR amplification of 16s rRNA genes was obtained when archaea-specific primers were used.

  19. Enhanced propylene production in FCC by novel catalytic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, C.P.; Harris, D.; Xu, M.; Fu, J. [BASF Catalyst LLC, Iselin, NJ (United States)

    2007-07-01

    Fluid catalytic cracking is expected to increasingly supply the additional incremental requirements for propylene. The most efficient route to increase propylene yield from an FCC unit is through the use of medium pore zeolites such as ZSM-5. ZSM-5 zeolite cracks near linear olefins in the gasoline range to LPG olefins such as propylene and butylenes. This paper will describe catalytic approaches to increase gasoline range olefins and the chemistry of ZSM-5 to crack those olefins. The paper will also describe novel catalytic materials designed to increase propylene. (orig.)

  20. Bio-Inspired Molecular Catalysts for Hydrogen Oxidation and Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Ming-Hsun; Chen, Shentan; Rousseau, Roger J.; Dupuis, Michel; Bullock, R. Morris; Raugei, Simone

    2013-06-03

    Recent advances in Ni-based bio-inspired catalysts obtained in the Center for Molecular Electrocatalysis, an Energy Frontier Research Center (EFRC) at the Pacific Northwest National Laboratory, demonstrated the possibility of cleaving H2 or generating H2 heterolytically with turnover frequencies comparable or superior to those of hydrogenase enzymes. In these catalysts the transformation between H2 and protons proceeds via an interplay between proton, hydride and electron transfer steps and involves the interaction of a dihydrogen molecule with both a Ni(II) center and with pendant amine bases incorporated in a six-membered ring, which act as proton relays. These catalytic platforms are well designed in that when protons are correctly positioned (endo) toward the Raugei-ACS-Books.docxPrinted 12/18/12 2 metal center, catalysis proceeds at very high rates. We will show that the proton removal (for H2 oxidation) and proton delivery (for H2 production) are often the rate determining steps. Furthermore, the presence of multiple protonation sites gives rise to reaction intermediates with protons not correctly positioned (exo relative to the metal center). These isomers are easily accessible kinetically and are detrimental to catalysis because of the slow isomerization processes necessary to convert them to the catalytically competent endo isomers. In this chapter we will review the major findings of our computational investigation on the role of proton relays for H2 chemistry and provide guidelines for the design of new catalysts. This research was carried out in the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science. Pacific Northwest National Laboratory is operated for the U.S. Department of Energy by Battelle. Computational resources were provided at W. R. Wiley Environmental Molecular Science Laboratory (EMSL), a Raugei-Bio-Inspired Molecular-Catalysts-for-Hydrogen- Oxidation-and-Hydrogen-Production

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

    International Nuclear Information System (INIS)

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

  2. Hydrogen in the Methanol Production Process

    Science.gov (United States)

    Kralj, Anita Kovac; Glavic, Peter

    2006-01-01

    Hydrogen is a very important industrial gas in chemical processes. It is very volatile; therefore, it can escape from the process units and its mass balance is not always correct. In many industrial processes where hydrogen is reacted, kinetics are often related to hydrogen pressure. The right thermodynamic properties of hydrogen can be found for…

  3. Field-controlled electron transfer and reaction kinetics of the biological catalytic system of microperoxidase-11 and hydrogen peroxide

    OpenAIRE

    Yongki Choi; Siu-Tung Yau

    2011-01-01

    Controlled reaction kinetics of the bio-catalytic system of microperoxidase-11 and hydrogen peroxide has been achieved using an electrostatic technique. The technique allowed independent control of 1) the thermodynamics of the system using electrochemical setup and 2) the quantum mechanical tunneling at the interface between microperoxidase-11 and the working electrode by applying a gating voltage to the electrode. The cathodic currents of electrodes immobilized with microperoxidase-11 showed...

  4. Non-traditional Process of Hydrogen Containing Fuel Mixtures Production for Internal-combustion Engines

    OpenAIRE

    Gennady G. Kuvshinov; Maksim V. Popov; Evgeny A. Soloviev; Armen I. Arzumanyan; Georgy A. Peshkov

    2012-01-01

    The article justifies the perspectives of development of the environmentally sound technology of hydrogen containing fuel mixtures for internal-combustion engines based on the catalytic process of low-temperature decomposition of hydrocarbons into hydrogen and nanofibrous carbon.

  5. Biological hydrogen production from biomass by thermophilic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Claassen, P.A.M.; Mars, A.E.; Budde, M.A.W.; Lai, M.; de Vrije, T. [Wageningen UR, Agrotechnology and Food Sciences Group (AFSG), Business Unit Biobased Products, P.O. Box 17, 6700 AA Wageningen, (Netherlands); van Niel, E.W.J. [Lund University, Applied microbiology, P.O. Box 124, 221 000 Lund, (Sweden)

    2006-07-01

    To meet the reduction of the emission of CO{sub 2} imposed by the Kyoto protocol, hydrogen should be produced from renewable primary energy. Besides the indirect production of hydrogen by electrolysis using electricity from renewable resources, such as sunlight, wind and hydropower, hydrogen can be directly produced from biomass. At present, there are two strategies for the production of hydrogen from biomass: the thermochemical technology, such as gasification, and the biotechnological approach using micro-organisms. Biological hydrogen production delivers clean hydrogen with an environmental-friendly technology and is very suitable for the conversion of wet biomass in small-scale applications, thus having a high chance of becoming an economically feasible technology. Many micro-organisms are able to produce hydrogen from mono- and disaccharides, starch and (hemi)cellulose under anaerobic conditions. The anaerobic production of hydrogen is a common phenomenon, occurring during the process of anaerobic digestion. Here, hydrogen producing micro-organisms are in syn-trophy with methanogenic bacteria which consume the hydrogen as soon as it is produced. In this way, hydrogen production remains obscure and methane is the end-product. By uncoupling hydrogen production from methane production, hydrogen becomes available for recovery and exploitation. This study describes the use of extreme thermophilic bacteria, selected because of a higher hydrogen production efficiency as compared to mesophilic bacteria, for the production of hydrogen from renewable resources. As feedstock energy crops like Miscanthus and Sorghum bicolor and waste streams like domestic organic waste, paper sludge and potato steam peels were used. The feedstock was pretreated and/or enzymatically hydrolyzed prior to fermentation to make a fermentable substrate. Hydrogen production by Caldicellulosiruptor saccharolyticus, Thermotoga elfii and T. neapolitana on all substrates was observed. Nutrient

  6. Biological hydrogen production from biomass by thermophilic bacteria

    International Nuclear Information System (INIS)

    To meet the reduction of the emission of CO2 imposed by the Kyoto protocol, hydrogen should be produced from renewable primary energy. Besides the indirect production of hydrogen by electrolysis using electricity from renewable resources, such as sunlight, wind and hydropower, hydrogen can be directly produced from biomass. At present, there are two strategies for the production of hydrogen from biomass: the thermochemical technology, such as gasification, and the biotechnological approach using micro-organisms. Biological hydrogen production delivers clean hydrogen with an environmental-friendly technology and is very suitable for the conversion of wet biomass in small-scale applications, thus having a high chance of becoming an economically feasible technology. Many micro-organisms are able to produce hydrogen from mono- and disaccharides, starch and (hemi)cellulose under anaerobic conditions. The anaerobic production of hydrogen is a common phenomenon, occurring during the process of anaerobic digestion. Here, hydrogen producing micro-organisms are in syn-trophy with methanogenic bacteria which consume the hydrogen as soon as it is produced. In this way, hydrogen production remains obscure and methane is the end-product. By uncoupling hydrogen production from methane production, hydrogen becomes available for recovery and exploitation. This study describes the use of extreme thermophilic bacteria, selected because of a higher hydrogen production efficiency as compared to mesophilic bacteria, for the production of hydrogen from renewable resources. As feedstock energy crops like Miscanthus and Sorghum bicolor and waste streams like domestic organic waste, paper sludge and potato steam peels were used. The feedstock was pretreated and/or enzymatically hydrolyzed prior to fermentation to make a fermentable substrate. Hydrogen production by Caldicellulosiruptor saccharolyticus, Thermotoga elfii and T. neapolitana on all substrates was observed. Nutrient requirements

  7. Hydrogen Gas Production from Nuclear Power Plant in Relation to Hydrogen Fuel Cell Technologies Nowadays

    Science.gov (United States)

    Yusibani, Elin; Kamil, Insan; Suud, Zaki

    2010-06-01

    Recently, world has been confused by issues of energy resourcing, including fossil fuel use, global warming, and sustainable energy generation. Hydrogen may become the choice for future fuel of combustion engine. Hydrogen is an environmentally clean source of energy to end-users, particularly in transportation applications because without release of pollutants at the point of end use. Hydrogen may be produced from water using the process of electrolysis. One of the GEN-IV reactors nuclear projects (HTGRs, HTR, VHTR) is also can produce hydrogen from the process. In the present study, hydrogen gas production from nuclear power plant is reviewed in relation to commercialization of hydrogen fuel cell technologies nowadays.

  8. Decentralized and direct solar hydrogen production: Towards a hydrogen economy in MENA region

    Energy Technology Data Exchange (ETDEWEB)

    Bensebaa, Farid; Khalfallah, Mohamed; Ouchene, Majid

    2010-09-15

    Hydrogen has certainly some advantages in spite of its high cost and low efficiency when compared to other energy vectors. Solar energy is an abundant, clean and renewable source of energy, currently competing with fossil fuel for water heating without subsidy. Photo-electrochemical, thermo-chemicals and photo-biological processes for hydrogen production processes have been demonstrated. These decentralised hydrogen production processes using directly solar energy do not require expensive hydrogen infrastructure for packaging and delivery in the short and medium terms. MENA region could certainly be considered a key area for a new start to a global deployment of hydrogen economy.

  9. Hydrogen Production from Hydrogen Sulfide in IGCC Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Elias Stefanakos; Burton Krakow; Jonathan Mbah

    2007-07-31

    IGCC power plants are the cleanest coal-based power generation facilities in the world. Technical improvements are needed to help make them cost competitive. Sulfur recovery is one procedure in which improvement is possible. This project has developed and demonstrated an electrochemical process that could provide such an improvement. IGCC power plants now in operation extract the sulfur from the synthesis gas as hydrogen sulfide. In this project H{sub 2}S has been electrolyzed to yield sulfur and hydrogen (instead of sulfur and water as is the present practice). The value of the byproduct hydrogen makes this process more cost effective. The electrolysis has exploited some recent developments in solid state electrolytes. The proof of principal for the project concept has been accomplished.

  10. Nuclear Hydrogen for Peak Electricity Production and Spinning Reserve

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.

    2005-01-20

    Nuclear energy can be used to produce hydrogen. The key strategic question is this: ''What are the early markets for nuclear hydrogen?'' The answer determines (1) whether there are incentives to implement nuclear hydrogen technology today or whether the development of such a technology could be delayed by decades until a hydrogen economy has evolved, (2) the industrial partners required to develop such a technology, and (3) the technological requirements for the hydrogen production system (rate of production, steady-state or variable production, hydrogen purity, etc.). Understanding ''early'' markets for any new product is difficult because the customer may not even recognize that the product could exist. This study is an initial examination of how nuclear hydrogen could be used in two interconnected early markets: the production of electricity for peak and intermediate electrical loads and spinning reserve for the electrical grid. The study is intended to provide an initial description that can then be used to consult with potential customers (utilities, the Electric Power Research Institute, etc.) to better determine the potential real-world viability of this early market for nuclear hydrogen and provide the starting point for a more definitive assessment of the concept. If this set of applications is economically viable, it offers several unique advantages: (1) the market is approximately equivalent in size to the existing nuclear electric enterprise in the United States, (2) the entire market is within the utility industry and does not require development of an external market for hydrogen or a significant hydrogen infrastructure beyond the utility site, (3) the technology and scale match those of nuclear hydrogen production, (4) the market exists today, and (5) the market is sufficient in size to justify development of nuclear hydrogen production techniques independent of the development of any other market for hydrogen

  11. Membrane catalysis in the dehydrogenation and hydrogen production processes

    International Nuclear Information System (INIS)

    Data on the applications of membrane catalysis in the dehydrogenation of organic compounds and hydrogen production are analyzed and generalized. It is shown that the integration of membrane reactors into existing plants is necessary for production of hydrogen of high purity. The steam reforming and oxidative reforming of methane and steam reforming of light alcohols seem to be the most promising processes for hydrogen production in membrane reactors. The bibliography includes 165 references.

  12. Bio-hydrogen Production Potential from Market Waste

    OpenAIRE

    Lanna Jaitalee; Orathai Chavalparit

    2010-01-01

    This research studied bio-hydrogen production from vegetable waste from a fresh market in order to recover energy. A series of batch experiments were conducted to investigate the effects of initial volatile solids concentration on the bio-hydrogen production process. Lab bench scale anaerobic continuous stirred-tank reactors (CSTR) were used to study the effect of substrate and sludge inoculation on hydrogen production. Three different concentrations of initial total volatile solids (TVS) of ...

  13. Fermentation and Electrohydrogenic Approaches to Hydrogen Production (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Maness, P. C.; Thammannagowda, S.; Magnusson, L.; Logan, B.

    2010-06-01

    This work describes the development of a waste biomass fermentation process using cellulose-degrading bacteria for hydrogen production. This process is then integrated with an electrohydrogenesis process via the development of a microbial electrolysis cell reactor, during which fermentation waste effluent is further converted to hydrogen to increase the total output of hydrogen from biomass.

  14. Solar Thermochemical Hydrogen Production Research (STCH)

    Energy Technology Data Exchange (ETDEWEB)

    Perret, Robert [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2011-05-01

    Eight cycles in a coordinated set of projects for Solar Thermochemical Cycles for Hydrogen production (STCH) were self-evaluated for the DOE-EERE Fuel Cell Technologies Program at a Working Group Meeting on October 8 and 9, 2008. This document reports the initial selection process for development investment in STCH projects, the evaluation process meant to reduce the number of projects as a means to focus resources on development of a few most-likely-to-succeed efforts, the obstacles encountered in project inventory reduction and the outcomes of the evaluation process. Summary technical status of the projects under evaluation is reported and recommendations identified to improve future project planning and selection activities.

  15. Pt nanoparticles modified by rare earth oxides: Electronic effect and influence to catalytic hydrogenation of 3-phenoxybenzaldehyde

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • The rare earths modified Pt/Al2O3 were prepared by colloidal deposition method. • Modification of Pt by the rare earth enhanced catalytic hydrogenation activity. • The activity improvement is due to electron interaction between Pt and rare earth. • The hydrogenation mechanism of rare earth modified Pt catalyst was proposed. - Abstract: The rare earth elements (La, Ce, Nd, Sm, Pr, and Gd) modified Pt/Al2O3 catalysts were prepared by the colloidal deposition and chemical reduction methods, respectively. Pt nanoparticles with average size 3 ± 0.5 nm were uniformly dispersed on the surface of Al2O3 for the samples prepared by the colloidal deposition method, which exhibited higher activities in the hydrogenation of 3-phenoxybenzadehyde than the corresponding samples prepared by chemical reduction method. Moreover, except Gd, the catalysts modified by rare earth elements showed better catalytic performance than unmodified Pt/Al2O3. For Pt–Ce/Al2O3 catalyst, when the weight percent of Pt and Ce was 0.5 and 0.25, respectively, the hydrogenation conversion of 3-phenoxybenzaldehyde was 97.3% after 6 h reaction. This activity improvement is due to the electronic interaction between Pt and rare earth elements, which was investigated by X-ray photoelectron spectroscopy

  16. A review on hydrogen production: methods, materials and nanotechnology.

    Science.gov (United States)

    Lang, Yizhao; Arnepalli, Ranga Rao; Tiwari, Ashutosh

    2011-05-01

    In recent years hydrogen production and storage has attracted a lot of attention in both academia and industry due to its variety of applications in energy sector. Hydrogen is recognized as one of the most important components of the next generation clean energy technology. Within the whole cycle of the use of hydrogen energy, hydrogen production is considered as the key element of the upcoming hydrogen economy. Since the first production method invented for hydrogen on a smaller scale by dissolving iron in the acid vitriol in the 15th century, many improvements have been made to make the production viable and more cost effective. It is known that "nano" is playing its role in many technologies from medicine to material science and it has its say even in the production of hydrogen energy with continuous improvements in materials and methodologies. In this review we attempt to list various methods of producing hydrogen from different sources of materials followed by the description of most recent developments in the materials prospective. We explain the role of nanotechnology in making the hydrogen production technology a viable and cost effective process. The chemical reaction cycle, mechanism and configurations of various methods of hydrogen production are elaborated. PMID:21780363

  17. A New Hydrogen-Producing Strain and Its Characterization of Hydrogen Production.

    Science.gov (United States)

    Sun, Mingxing; Lv, Yongkang; Liu, Yuxiang

    2015-12-01

    A newly isolated photo non-sulfur (PNS) bacterium was identified as Rhodopseudomonas palustris PB-Z by sequencing of 16S ribosomal DNA (rDNA) genes and phylogenetic analysis. Under vigorous stirring (240 rpm), the hydrogen production performances were greatly improved: The maximum hydrogen production rate and cumulative hydrogen production increased by 188.9 ± 0.07 % and 83.0 ± 0.06 %, respectively, due to the hydrogen bubbles were immediately removed from the culture medium. The effects of different wavelength of light on hydrogen production with stirring were much different from that without stirring. The ranking on the photo-hydrogen production performance was white > yellow > green > blue > red without stirring and white > yellow > blue > red > green under stirring. The best light source for hydrogen production was tungsten filament lamp. The optimum temperature was 35 °C. The maximal hydrogen production rate and cumulative hydrogen production reached 78.7 ± 2.3 ml/l/h and 1728.1 ± 92.7 mol H2/l culture, respectively, under 35 °C, 240 rpm, and illumination of 4000 lux. Pyruvate was one of the main sources of CO2 and has a great impact on the gas composition.

  18. An integrated system of gasoline reformer and three way converter for on-board hydrogen production

    International Nuclear Information System (INIS)

    On-board exhaust gas assisted gasoline reforming has been investigated using a compact prototype system consisting of a fuel reformer integrated with a three way catalytic converter (TWC) connected to a V6 engine running at homogeneous charge compression ignition (HCCI) mode, the integrated fuel reformer and TWC were designed and constructed to supply reformed exhaust gas recirculation (REGR) stream to the gasoline-fuelled HCCI V6 engine as supplement fuel to improve engine performance and reduce NOx emissions. To find the optimum operating conditions of the engine-reformer system (in terms of hydrogen production and thermal efficiency), the effect of oxygen to carbon ratio (O2/C) in the reactor input mixture, and the different engine operating conditions were investigated. The reactor outlet temperature appears to be strongly correlated to the production of hydrogen, concentrations up to 12.8% of hydrogen in the reformer products were achieved from commercial unleaded gasoline. Uncompleted reforming of gasoline was assumed from significant quantities of hydrocarbons in the product measured by Non-Dispersive Infrared (NDIR). This novel design of an integrated fuel reformer and three-way catalytic converter (TWC) that can be fitted in the EGR loop was applied to extend the lower boundary of the (HCCI) operating window.(author)

  19. Energy Efficient Catalytic Activation of Hydrogen peroxide for Green Chemical Processes: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Terrence J.; Horwitz, Colin

    2004-11-12

    A new, highly energy efficient approach for using catalytic oxidation chemistry in multiple fields of technology has been pursued. The new catalysts, called TAML® activators, catalyze the reactions of hydrogen peroxide and other oxidants for the exceptionally rapid decontamination of noninfectious simulants (B. atrophaeus) of anthrax spores, for the energy efficient decontamination of thiophosphate pesticides, for the facile, low temperature removal of color and organochlorines from pulp and paper mill effluent, for the bleaching of dyes from textile mill effluents, and for the removal of recalcitrant dibenzothiophene compounds from diesel and gasoline fuels. Highlights include the following: 1) A 7-log kill of Bacillus atrophaeus spores has been achieved unambiguously in water under ambient conditions within 15 minutes. 2) The rapid total degradation under ambient conditions of four thiophosphate pesticides and phosphonate degradation intermediates has been achieved on treatment with TAML/peroxide, opening up potential applications of the decontamination system for phosphonate structured chemical warfare agents, for inexpensive, easy to perform degradation of stored and aged pesticide stocks (especially in Africa and Asia), for remediation of polluted sites and water bodies, and for the destruction of chemical warfare agent stockpiles. 3) A mill trial conducted in a Pennsylvanian bleached kraft pulp mill has established that TAML catalyst injected into an alkaline peroxide bleach tower can significantly lower color from the effluent stream promising a new, more cost effective, energy-saving approach for color remediation adding further evidence of the value and diverse engineering capacity of the approach to other field trials conducted on effluent streams as they exit the bleach plant. 4) Dibenzothiophenes (DBTs), including 4,6-dimethyldibenzothiophene, the most recalcitrant sulfur compounds in diesel and gasoline, can be completely removed from model gasoline

  20. Methods and systems for the production of hydrogen

    Science.gov (United States)

    Oh, Chang H.; Kim, Eung S.; Sherman, Steven R.

    2012-03-13

    Methods and systems are disclosed for the production of hydrogen and the use of high-temperature heat sources in energy conversion. In one embodiment, a primary loop may include a nuclear reactor utilizing a molten salt or helium as a coolant. The nuclear reactor may provide heat energy to a power generation loop for production of electrical energy. For example, a supercritical carbon dioxide fluid may be heated by the nuclear reactor via the molten salt and then expanded in a turbine to drive a generator. An intermediate heat exchange loop may also be thermally coupled with the primary loop and provide heat energy to one or more hydrogen production facilities. A portion of the hydrogen produced by the hydrogen production facility may be diverted to a combustor to elevate the temperature of water being split into hydrogen and oxygen by the hydrogen production facility.

  1. The endogenous production of hydrogen sulphide in intrauterine tissues

    OpenAIRE

    Wang Rui; Heptinstall John; Vatish Manu; Patel Pushpa; Carson Ray J

    2009-01-01

    Abstract Background Hydrogen sulphide is a gas signalling molecule which is produced endogenously from L-cysteine via the enzymes cystathionine beta-synthase (CBS) and cystathionine gamma-lyase (CSE). The possible role of hydrogen sulphide in reproduction has not yet been fully investigated. It has been previously demonstrated that hydrogen sulphide relaxes uterine smooth muscle in vitro. The aim of the present study was to investigate the endogenous production of hydrogen sulphide in rat and...

  2. An Experimental Investigation of Hydrogen Production from Biomass

    Institute of Scientific and Technical Information of China (English)

    吕鹏梅; 常杰; 付严; 王铁军; 陈勇; 祝京旭

    2003-01-01

    In gaseous products of biomass steam gasification, there exist a lot of CO, CH4 and other hydrocarbons that can be converted to hydrogen through steam reforming reactions. There exists potential hydrogen production from the raw gas of biomass steam gasification. In the present work, the characteristics of hydrogen production from biomass steam gasification were investigated in a small-scale fluidized bed. In these experiments, the gasifying agent (air) was supplied into the reactor from the bottom of the reactor and the steam was added into the reactor above biomass feeding location. The effects of reaction temperature, steam to biomass ratio, equivalence ratio (ER) and biomass particle size on hydrogen yield and hydrogen yield potential were investigated. The experimental results showed that higher reactor temperature, proper ER, proper steam to biomass ratio and smaller biomass particle size will contribute to more hydrogen and potential hydrogen yield.

  3. Fluid-Bed Testing of Greatpoint Energy's Direct Oxygen Injection Catalytic Gasification Process for Synthetic Natural Gas and Hydrogen Coproduction Year 6 - Activity 1.14 - Development of a National Center for Hydrogen Technology

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, Michael; Henderson, Ann

    2012-04-01

    The GreatPoint Energy (GPE) concept for producing synthetic natural gas and hydrogen from coal involves the catalytic gasification of coal and carbon. GPE’s technology “refines” coal by employing a novel catalyst to “crack” the carbon bonds and transform the coal into cleanburning methane (natural gas) and hydrogen. The GPE mild “catalytic” gasifier design and operating conditions result in reactor components that are less expensive and produce pipeline-grade methane and relatively high purity hydrogen. The system operates extremely efficiently on very low cost carbon sources such as lignites, subbituminous coals, tar sands, petcoke, and petroleum residual oil. In addition, GPE’s catalytic coal gasification process eliminates troublesome ash removal and slagging problems, reduces maintenance requirements, and increases thermal efficiency, significantly reducing the size of the air separation plant (a system that alone accounts for 20% of the capital cost of most gasification systems) in the catalytic gasification process. Energy & Environmental Research Center (EERC) pilot-scale gasification facilities were used to demonstrate how coal and catalyst are fed into a fluid-bed reactor with pressurized steam and a small amount of oxygen to “fluidize” the mixture and ensure constant contact between the catalyst and the carbon particles. In this environment, the catalyst facilitates multiple chemical reactions between the carbon and the steam on the surface of the coal. These reactions generate a mixture of predominantly methane, hydrogen, and carbon dioxide. Product gases from the process are sent to a gas-cleaning system where CO{sub 2} and other contaminants are removed. In a full-scale system, catalyst would be recovered from the bottom of the gasifier and recycled back into the fluid-bed reactor. The by-products (such as sulfur, nitrogen, and CO{sub 2}) would be captured and could be sold to the chemicals and petroleum industries, resulting in

  4. Present status of research on hydrogen energy and perspective of HTGR hydrogen production system

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Yoshiaki; Ogawa, Masuro; Akino, Norio [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment] [and others

    2001-03-01

    A study was performed to make a clear positioning of research and development on hydrogen production systems with a High Temperature Gas-cooled Reactor (HTGR) under currently promoting at the Japan Atomic Energy Research Institute through a grasp of the present status of hydrogen energy, focussing on its production and utilization as an energy in future. The study made clear that introduction of safe distance concept for hydrogen fire and explosion was practicable for a HTGR hydrogen production system, including hydrogen properties and need to provide regulations applying to handle hydrogen. And also generalization of hydrogen production processes showed technical issues of the HTGR system. Hydrogen with HTGR was competitive to one with fossil fired system due to evaluation of production cost. Hydrogen is expected to be used as promising fuel of fuel cell cars in future. In addition, the study indicated that there were a large amount of energy demand alternative to high efficiency power generation and fossil fuel with nuclear energy through the structure of energy demand and supply in Japan. Assuming that hydrogen with HTGR meets all demand of fuel cell cars, an estimation would show introduction of the maximum number of about 30 HTGRs with capacity of 100 MWt from 2020 to 2030. (author)

  5. Present status of research on hydrogen energy and perspective of HTGR hydrogen production system

    International Nuclear Information System (INIS)

    A study was performed to make a clear positioning of research and development on hydrogen production systems with a High Temperature Gas-cooled Reactor (HTGR) under currently promoting at the Japan Atomic Energy Research Institute through a grasp of the present status of hydrogen energy, focussing on its production and utilization as an energy in future. The study made clear that introduction of safe distance concept for hydrogen fire and explosion was practicable for a HTGR hydrogen production system, including hydrogen properties and need to provide regulations applying to handle hydrogen. And also generalization of hydrogen production processes showed technical issues of the HTGR system. Hydrogen with HTGR was competitive to one with fossil fired system due to evaluation of production cost. Hydrogen is expected to be used as promising fuel of fuel cell cars in future. In addition, the study indicated that there were a large amount of energy demand alternative to high efficiency power generation and fossil fuel with nuclear energy through the structure of energy demand and supply in Japan. Assuming that hydrogen with HTGR meets all demand of fuel cell cars, an estimation would show introduction of the maximum number of about 30 HTGRs with capacity of 100 MWt from 2020 to 2030. (author)

  6. Catalytic hydrolysis of ammonia borane for hydrogen generation using cobalt nanocluster catalyst supported on polydopamine functionalized multiwalled carbon nanotube

    International Nuclear Information System (INIS)

    Hydrogen was generated from ammonia borane complex by hydrolysis using cobalt nanocluster catalyst supported on polydopamine functionalized MWCNTs (multi-walled carbon nanotubes). The impregnation-chemical reduction method was used for the preparation of the supported catalyst. The nanocluster catalyst support was formed by in-situ oxidative polymerization of dopamine on the MWCNTs in alkaline solution at room temperature. The structural and physical–chemical properties of the nanocluster catalyst were characterized by FT-IR (Fourier transform infrared spectroscopy), EDX (energy-dispersive X-ray spectroscopy), SEM (scanning electron microscope), XRD (X-ray diffraction) and TEM (transmission electron microscopy). The nanocluster catalyst showed good catalytic activity for the hydrogen generation from aqueous ammonia borane complex. A reusability test to determine the practical usage of the catalyst was also investigated. The result revealed that the catalyst maintained an appreciable catalytic performance and stability in terms of its reusability after three cycle of reuse for the hydrolysis reaction. Also, the activation energy for the hydrolysis of ammonia borane complex was estimated to be 50.41 kJmol−1, which is lower than the values of some of the reported catalyst. The catalyst can be considered as a promising candidate in developing highly efficient portable hydrogen generation systems such as PEMFC (proton exchange membrane fuel cells). - Highlights: • Co/Pdop-o-MWCNT (Pdop functionalized MWCNT supported cobalt nanocluster) catalyst was synthesized for hydrogen generation. • It is an active catalyst for hydrogen generation via hydrolysis of ammonia borane. • It showed good stability in terms of reusability for the hydrogen generation

  7. Catalytic performance of Fe modified K/Mo2C catalyst for CO hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Minglin Xiang; Dudu Wu; Juan Zou; Debao Li; Yuhan Sun; Xichun She

    2011-01-01

    Fe modified and un-modified K/Mo2C were prepared and investigated as catalysts for CO hydrogenation reaction.Compared with K/Mo2C catalyst,the addition of Fe increased the production of alcohols,especially the C2+OH.Meanwhile,considerable amounts of C5+ hydrocarbons and C=2-C=4 were formed,whereas methane selectivity greatly decreased.Also,the activity and selectivity of the catalyst were readily affected by the reaction pressure and temperature employed.According to the XPS results,Mo4+ might be responsible for the production of alcohols,whereas the low valence state of Mo species such as Moo and/or Mo2+ might be account for the high activity and selectivity toward hydrocarbons.

  8. Research Progress in Catalytic Hydrogenation of CO2 to Ethanol%CO2催化加氢制乙醇研究进展

    Institute of Scientific and Technical Information of China (English)

    王慧敏; 杨绪壮; 张兵兵; 苏海全

    2012-01-01

    燃料乙醇是可再生的清洁燃料,具有替代汽油的应用前景.以CO2气体为碳源并通过催化加氢制燃料乙醇具有环境保护和节约能源的现实意义.主要介绍了CO2催化加氢的反应机理以及催化剂活性组分、前驱物、助剂及载体对催化活性、产物选择性的影响,同时介绍了反应条件对催化过程的影响.%Fuel ethanol is often regarded as a potential renewable clean alternative fuel to gasoline. It has practical significance of environmental protection and energy conservation to synthesize fuel ethanol by the hydrogenation of CO2. The reaction mechanism of catalytic hydrogenation of CO2 to ethanol as well as the effects of active sites,precursors,promoters and supports on the catalytic activity and product selectivity are reviewed. Moreover,the effects of reaction conditions on the catalysis are also introduced.

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

    Energy Technology Data Exchange (ETDEWEB)

    Trewyn, Brian G.; Smith, Ryan G.

    2016-07-05

    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 foundation for the future production of

  10. 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

  11. A strategy for enhancing fermentative hydrogen production from molasses

    Energy Technology Data Exchange (ETDEWEB)

    Chiu-Yue Lin; Chong-Yi Lin; Jou-Hsien Wu [Biohydrogen Lab, Graduate Institute of Civil and Hydraulic Engineering, Feng Chia University, P.O. Box 25-123, Taichung 407, Taiwan (China); Chin-Chao Chen [Department of Landscape Architecture, Chungchou Institute of Technology, Changhwa, Taiwan (China)

    2006-07-01

    This study investigated the enhancements of reactor performance by influent pretreatment for hydrogen production from molasses by a natural mixed culture enriched from sewage sludge. The reactor was operated at a temperature of 35{+-}1 C, a substrate molasses concentration of 40 g-COD/L and hydraulic retention times of 8-4 h. The thermal pretreatments on influent molasses was at 70 C for 10 min. Thermal pretreatment on the influent molasses markedly enhanced the hydrogen production and reactor performance stability. The pretreatment reactor exhibited marked increases in hydrogen content and hydrogen production rate by 40% and 35%, respectively, relative to the non-pretreatment reactor. The pretreatment reactor had hydrogen yield of 1 mmol-H{sub 2}/g-COD and specific hydrogen production rate of 6 mmol-H{sub 2}/g-VSS-day which efficiency is comparable to that of using synthetic wastewaters such as sucrose and glucose. (authors)

  12. A strategy for enhancing fermentative hydrogen production from molasses

    International Nuclear Information System (INIS)

    This study investigated the enhancements of reactor performance by influent pretreatment for hydrogen production from molasses by a natural mixed culture enriched from sewage sludge. The reactor was operated at a temperature of 35±1 C, a substrate molasses concentration of 40 g-COD/L and hydraulic retention times of 8-4 h. The thermal pretreatments on influent molasses was at 70 C for 10 min. Thermal pretreatment on the influent molasses markedly enhanced the hydrogen production and reactor performance stability. The pretreatment reactor exhibited marked increases in hydrogen content and hydrogen production rate by 40% and 35%, respectively, relative to the non-pretreatment reactor. The pretreatment reactor had hydrogen yield of 1 mmol-H2/g-COD and specific hydrogen production rate of 6 mmol-H2/g-VSS-day which efficiency is comparable to that of using synthetic wastewaters such as sucrose and glucose. (authors)

  13. A microBio reactor for hydrogen production.

    Energy Technology Data Exchange (ETDEWEB)

    Volponi, Joanne V.; Walker, Andrew William

    2003-12-01

    The purpose of this work was to explore the potential of developing a microfluidic reactor capable of enzymatically converting glucose and other carbohydrates to hydrogen. This aggressive project was motivated by work in enzymatic hydrogen production done by Woodward et al. at OWL. The work reported here demonstrated that hydrogen could be produced from the enzymatic oxidation of glucose. Attempts at immobilizing the enzymes resulted in reduced hydrogen production rates, probably due to buffer compatibility issues. A novel in-line sensor was also developed to monitor hydrogen production in real time at levels below 1 ppm. Finally, a theoretical design for the microfluidic reactor was developed but never produced due to the low production rates of hydrogen from the immobilized enzymes. However, this work demonstrated the potential of mimicking biological systems to create energy on the microscale.

  14. Catalytic combustion in environmental protection and energy production

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstroem-Silversand, F.

    1996-12-01

    This thesis is focused on three different areas of catalytic combustion: -Catalytic combustion of diesel soot, -Development of catalytically active wire meshes through thermal spraying, -Stabilisation and activation of {gamma}-alumina for methane combustion. Emissions of diesel soot may be trapped and combusted in a particulate trap coated with catalytically active materials. The soot particles must be combusted at temperatures prevailing in diesel exhausts, generally between 150 and 400 deg C. To facilitate effective combustion at these temperatures, the particulate trap should be coated with an oxide catalyst consisting of V{sub 2}O{sub 5}/CuO (V:Cu=0.9 on molar basis). Catalytically active wire meshes offer a number of advantages over pellets and monolith catalysts. They combine geometric flexibility with excellent mass- and heat- transfer characteristics and a low pressure drop. By using a modified thermal spray technique, it is possible to produce porous adhesive ceramic coatings on metal surfaces. The specific surface area can be increased through deposition of a high-surface-area material into the macro-porosity of the as-sprayed layer. The ceramic layer is finally activated through a conventional impregnation technique. Palladium dispersed onto a Si-stabilised {gamma}-alumina is an appropriate combustion catalyst at temperatures below 1000 deg C. Adding small amounts of rhodium or platinum to the palladium increases the catalyst activity but decreases the catalyst`s stability to thermal deactivation. The addition of rare-earth-metal oxides will lead to increased thermal stability but to a decreased activity. Long-term deactivation tests show that the activity for combustion of methane decreases to the same extent as the value of the specific surface area, thus indicating that the alumina surface may play an important role during the activation of adsorbed methane molecules. 29 refs, 14 figs

  15. Hydrogen-donors in petroleum products

    Energy Technology Data Exchange (ETDEWEB)

    Ermann, M.; Ecker, A. [Oesterreichisches Forschungszentrum Seibersdorf GmbH, Vienna (Austria). Research Inst. for Chemistry and Technology of Petroleum Products; Diwald, O.; Knoezinger, E. [Vienna Univ. (Austria). Inst. fuer Physikalische Chemie

    1998-12-01

    The radical scavenging abilities of hydrogen-donating compounds and of petroleum products were tested toward N,N-diphenylpicrylhydrazyl (DPPH). Selected samples were examined by heating at 50 C, for 3 h with DPPH. The changes in colour of the solution and of the ESR spectra are a measurement of the radical scavenging ability. By comparison of the results obtained by UV/VIS-photometry and by ESR-spectroscopy, a clear disadvantage of the photometric method was pointed out. Despite of that, it was found out that petroleum products, depending on the boiling range, have excellent radical scavenging properties and can generally be tested as thermal stabilisers. (orig.) [Deutsch] Die radikalfangenden Eigenschaften von Wasserstoff-abgebenden Verbindungen und von Raffineriestroemen wurden mit N,N-Diphenylpicrylhydrazyl (DPPH) getestet. Ausgewaehlte Proben wurden durch Erhitzen fuer 3 h bei 50 C mit DPPH ueberprueft. Die Farbveraenderungen der Loesung und die Aenderung der ESR-Spektren sind ein Mass fuer die radikalfangenden Eigenschaften. Anhand des Vergleiches der Ergebnisse, die durch UV/VIS-Photometrie und durch ESR-Spektroskopie ermittelt wurden, wurde ein klarer Nachteil der photometrischen Bestimmungsmethode aufgezeigt. Ferner wiesen Raffineriestroeme, abhaengig von ihrem Siedebereich, ausgezeichnete radikalfangende Faehigkeiten auf und koennen im weiterem Sinne als thermische Stabilisatoren getestet und eingesetzt werden. (orig.)

  16. Production of negative hydrogen ions on metal grids

    Energy Technology Data Exchange (ETDEWEB)

    Oohara, W.; Maetani, Y.; Takeda, Takashi; Takeda, Toshiaki; Yokoyama, H.; Kawata, K. [Department of Electronic Device Engineering, Yamaguchi University, Ube 755-8611 (Japan)

    2015-03-15

    Negative hydrogen ions are produced on a nickel grid with positive-ion irradiation. In order to investigate the production mechanism, a copper grid without the chemisorption of hydrogen atoms and positive helium ions without negative ionization are used for comparison. Positive hydrogen ions reflected on the metal surface obtain two electrons from the surface and become negatively ionized. It is found that the production yield of negative ions by desorption ionization of chemisorbed hydrogen atoms seems to be small, and the production is a minor mechanism.

  17. EVALUATING HYDROGEN PRODUCTION IN BIOGAS REFORMING IN A MEMBRANE REACTOR

    Directory of Open Access Journals (Sweden)

    F. S. A. Silva

    2015-03-01

    Full Text Available Abstract Syngas and hydrogen production by methane reforming of a biogas (CH4/CO2 = 2.85 using carbon dioxide was evaluated in a fixed bed reactor with a Pd-Ag membrane in the presence of a nickel catalyst (Ni 3.31% weight/γ-Al2O3 at 773 K, 823 K, and 873 K and 1.01×105 Pa. Operation with hydrogen permeation at 873 K increased the methane conversion to approximately 83% and doubled the hydrogen yield relative to operation without hydrogen permeation. A mathematical model was formulated to predict the evolution of the effluent concentrations. Predictions based on the model showed similar evolutions for yields of hydrogen and carbon monoxide at temperatures below 823 K for operations with and without the hydrogen permeation. The hydrogen yield reached approximately 21% at 823 K and 47% at 873 K under hydrogen permeation conditions.

  18. Hydrogen production from water: Recent advances in photosynthesis research

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, E.; Lee, J.W. [Oak Ridge National Lab., TN (United States). Chemical Technology Div.

    1997-12-31

    The great potential of hydrogen production by microalgal water splitting is predicated on quantitative measurement of the algae`s hydrogen-producing capability, which is based on the following: (1) the photosynthetic unit size of hydrogen production; (2) the turnover time of photosynthetic hydrogen production; (3) thermodynamic efficiencies of conversion of light energy into the Gibbs free energy of molecular hydrogen; (4) photosynthetic hydrogen production from sea water using marine algae; (5) the potential for research advances using modern methods of molecular biology and genetic engineering to maximize hydrogen production. ORNL has shown that sustained simultaneous photoevolution of molecular hydrogen and oxygen can be performed with mutants of the green alga Chlamydomonas reinhardtii that lack a detectable level of the Photosystem I light reaction. This result is surprising in view of the standard two-light reaction model of photosynthesis and has interesting scientific and technological implications. This ORNL discovery also has potentially important implications for maximum thermodynamic conversion efficiency of light energy into chemical energy by green plant photosynthesis. Hydrogen production performed by a single light reaction, as opposed to two, implies a doubling of the theoretically maximum thermodynamic conversion efficiency from {approx}10% to {approx}20%.

  19. Solar and Wind Technologies for Hydrogen Production Report to Congress

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2005-12-01

    DOE's Solar and Wind Technologies for Hydrogen Production Report to Congress summarizes the technology roadmaps for solar- and wind-based hydrogen production. Published in December 2005, it fulfills the requirement under section 812 of the Energy Policy Act of 2005.

  20. Maximizing Light Utilization Efficiency and Hydrogen Production in Microalgal Cultures

    Energy Technology Data Exchange (ETDEWEB)

    Melis, Anastasios [Univ. of California, Berkeley, CA (United States)

    2014-12-31

    The project addressed the following technical barrier from the Biological Hydrogen Production section of the Fuel Cell Technologies Program Multi-Year Research, Development and Demonstration Plan: Low Sunlight Utilization Efficiency in Photobiological Hydrogen Production is due to a Large Photosystem Chlorophyll Antenna Size in Photosynthetic Microorganisms (Barrier AN: Light Utilization Efficiency).

  1. Principle and perspectives of hydrogen production through biocatalyzed electrolysis

    NARCIS (Netherlands)

    Rozendal, R.A.; Hamelers, H.V.M.; Euverink, G.J.W.; Metz, S.J.; Buisman, C.J.N.

    2006-01-01

    Biocatalyzed electrolysis is a novel biological hydrogen production process with the potential to efficiently convert a wide range of dissolved organic materials in wastewaters. Even substrates formerly regarded to be unsuitable for hydrogen production due to the endothermic nature of the involved c

  2. Fermentative hydrogen production from agroindustrial lignocellulosic substrates

    Science.gov (United States)

    Reginatto, Valeria; Antônio, Regina Vasconcellos

    2015-01-01

    To achieve economically competitive biological hydrogen production, it is crucial to consider inexpensive materials such as lignocellulosic substrate residues derived from agroindustrial activities. It is possible to use (1) lignocellulosic materials without any type of pretreatment, (2) lignocellulosic materials after a pretreatment step, and (3) lignocellulosic materials hydrolysates originating from a pretreatment step followed by enzymatic hydrolysis. According to the current literature data on fermentative H2 production presented in this review, thermophilic conditions produce H2 in yields approximately 75% higher than those obtained in mesophilic conditions using untreated lignocellulosic substrates. The average H2 production from pretreated material is 3.17 ± 1.79 mmol of H2/g of substrate, which is approximately 50% higher compared with the average yield achieved using untreated materials (2.17 ± 1.84 mmol of H2/g of substrate). Biological pretreatment affords the highest average yield 4.54 ± 1.78 mmol of H2/g of substrate compared with the acid and basic pretreatment - average yields of 2.94 ± 1.85 and 2.41 ± 1.52 mmol of H2/g of substrate, respectively. The average H2 yield from hydrolysates, obtained from a pretreatment step and enzymatic hydrolysis (3.78 ± 1.92 mmol of H2/g), was lower compared with the yield of substrates pretreated by biological methods only, demonstrating that it is important to avoid the formation of inhibitors generated by chemical pretreatments. Based on this review, exploring other microorganisms and optimizing the pretreatment and hydrolysis conditions can make the use of lignocellulosic substrates a sustainable way to produce H2. PMID:26273246

  3. Anti-reflective nanoporous silicon for efficient hydrogen production

    Science.gov (United States)

    Oh, Jihun; Branz, Howard M

    2014-05-20

    Exemplary embodiments are disclosed of anti-reflective nanoporous silicon for efficient hydrogen production by photoelectrolysis of water. A nanoporous black Si is disclosed as an efficient photocathode for H.sub.2 production from water splitting half-reaction.

  4. Partial Characteristics of Hydrogen Production by Fermentative Hydrogen-producing Bacterial Strain B49

    Institute of Scientific and Technical Information of China (English)

    Wang Xiangjing(王相晶); Ren Nanqi; Xiang Wensheng; Lin Ming; Guo Wanqian

    2003-01-01

    To investigate the characteristics of hydrogen production by a novel fermentative hydrogen-producing bacterial strain B49 (AF481148 in EMBL), batch experiments are conducted under different conditions. Hydrogen production has a correlation with cell growth and the consumption of glucose and soluble protein. The optimum pH for cell growth is 4.5±0.15. At acidic pH 4.0±0.15, the bacteria has the maximum accumulated hydrogen volume of 2382 ml/L culture and the maximum hydrogen evolution rate of 339.9 ml/L culture*h with 1% glucose. The optimum temperature for cell growth and hydrogen production is 35℃. In addition, fermentative hydrogen-producing bacterial strain B49 can generate hydrogen from the decomposition of other organic substrates such as wheat, soybean, corn, and potato. Moreover, it can also produce hydrogen from molasses wastewater and brewage wastewater, and hydrogen yields are 137.9 ml H2/g COD and 49.9 ml H2/g COD, respectively.

  5. Effect of process variables on photosynthetic algal hydrogen production.

    Science.gov (United States)

    Hahn, John J; Ghirardi, Maria L; Jacoby, William A

    2004-01-01

    Chlamydomonas reinhardtii is a green alga that can use the sun's energy to split water into O(2) and H(2). This is accomplished by means of a two-phase cycle, an aerobic growth phase followed by an anaerobic hydrogen production phase. The effects of process variables on hydrogen production are examined here. These variables include cell concentration, light intensity, and reactor design parameters that affect light transport and mixing. An optimum cell concentration and light intensity are identified, and two reactor designs are compared. The maximum hydrogen production observed in this study was 0.29 mL of hydrogen per milliliter of suspension. This was measured at atmospheric pressure during a 96 h production cycle. This corresponds to an average hydrogen production rate of 0.12 mmol/mL.h. PMID:15176910

  6. General Tritium Labelling of Gentamicin C by catalytic hydrogen exchange Reaction with Tritiated Water

    International Nuclear Information System (INIS)

    Gentamicin C was labelled with tritium by means of a PtO2 catalyzed hydrogen exchange reaction. Under the conditions of the exchange (100 mg of gentamicin, basic form, 0,3 ml H2O-3H, and 50 mg of prereduced PtO2) the radiochemical yield was 0,24, 0,38 and 0,48 % at 120 degree celsius, for 8, 16 and 24 hours respectively. Chemical yield for purified gentamicin was about 60 %. Purification was accomplished with a cellulose column eluted with the lower phase of chloroform-methanol 17 % ammonium hydroxide (2:1:1, v/v) . Chemical purity, determined by HPLC, was 96,5 % and radiochemical one was 95. Main exchange degradation products show biological activity. (Author) 12 refs

  7. Catalytic Glycerol Hydrodeoxygenation under Inert Atmosphere: Ethanol as a Hydrogen Donor

    Directory of Open Access Journals (Sweden)

    Efterpi S. Vasiliadou

    2014-12-01

    Full Text Available Glycerol hydrodeoxygenation to 1,2-propanediol (1,2-PDO is a reaction of high interest. However, the need for hydrogen supply is a main drawback of the process. According to the concept investigated here, 1,2-propanediol is efficiently formed using bio-glycerol feedstock with H2 formed in situ via ethanol aqueous phase reforming. Ethanol is thought to be a promising H2 source, as it is alcohol that can be used instead of methanol for transesterification of oils and fats. The H2 generated is consumed in the tandem reaction of glycerol hydrodeoxygenation. The reaction cycle proceeds in liquid phase at 220–250 °C and 1.5–3.5 MPa initial N2 pressure for a 2 and 4-h reaction time. Pt-, Ni- and Cu-based catalysts have been synthesized, characterized and evaluated in the reaction. Among the materials tested, Pt/Fe2O3-Al2O3 exhibited the most promising performance in terms of 1,2-propanediol productivity, while reusability tests showed a stable behavior. Structural integrity and no formation of carbonaceous deposits were verified via Temperature Programmed Desorption of hydrogen (TPD-H2 and thermogravimetric analysis of the fresh and used Pt/FeAl catalyst. A study on the effect of various operating conditions (reaction time, temperature and pressure indicated that in order to maximize 1,2-propanediol productivity and yield, milder reaction conditions should be applied. The highest 1,2-propanediol yield, 53% (1.1 g1,2-PDO gcat−1·h−1, was achieved at a lower reaction temperature of 220 °C.

  8. Fermentative hydrogen production by microbial consortium

    Energy Technology Data Exchange (ETDEWEB)

    Maintinguer, Sandra I.; Fernandes, Bruna S.; Duarte, Iolanda C.S.; Saavedra, Nora Katia; Adorno, M. Angela T.; Varesche, M. Bernadete [Department of Hydraulics and Sanitation, School of Engineering of Sao Carlos, University of Sao Paulo, Av. Trabalhador Sao-carlense, 400, 13566-590 Sao Carlos-SP (Brazil)

    2008-08-15

    Heat pre-treatment of the inoculum associated to the pH control was applied to select hydrogen-producing bacteria and endospores-forming bacteria. The source of inoculum to the heat pre-treatment was from a UASB reactor used in the slaughterhouse waste treatment. The molecular biology analyses indicated that the microbial consortium presented microorganisms affiliated with Enterobacter cloacae (97% and 98%), Clostridium sp. (98%) and Clostridium acetobutyricum (96%), recognized as H{sub 2} and volatile acids' producers. The following assays were carried out in batch reactors in order to verify the efficiencies of sucrose conversion to H{sub 2} by the microbial consortium: (1) 630.0 mg sucrose/L, (2) 1184.0 mg sucrose/L, (3) 1816.0 mg sucrose/L and (4) 4128.0 mg sucrose/L. The subsequent yields were obtained as follows: 15% (1.2 mol H{sub 2}/mol sucrose), 20% (1.6 mol H{sub 2}/mol sucrose), 15% (1.2 mol H{sub 2}/mol sucrose) and 4% (0.3 mol H{sub 2}/mol sucrose), respectively. The intermediary products were acetic acid, butyric acid, methanol and ethanol in all of the anaerobic reactors. (author)

  9. Electrolytic production of hydrogen utilizing photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, M.A.

    1996-10-01

    Hydrogen has the potential to serve as both an energy storage means and an energy carrier in renewable energy systems. When renewable energy sources such as solar or wind power are used to produce electrical power, the output can vary depending on weather conditions. By using renewable sources to produce hydrogen, a fuel which can be stored and transported, a reliable and continuously available energy supply with a predictable long-term average output is created. Electrolysis is one method of converting renewable energy into hydrogen fuel. In this experiment we examine the use of an electrolyzer based on polymer-electrolyte membrane technology to separate water into hydrogen and oxygen. The oxygen is vented to the atmosphere and the hydrogen is stored in a small pressure vessel.

  10. Hydrogen production by the decomposition of water

    Science.gov (United States)

    Hollabaugh, C.M.; Bowman, M.G.

    A process is described for the production of hydrogen from water by a sulfuric acid process employing electrolysis and thermo-chemical decomposition. The water containing SO/sub 2/ is electrolyzed to produce H/sub 2/ at the cathode and to oxidize the SO/sub 2/ to form H/sub 2/SO/sub 4/ at the anode. After the H/sub 2/ has been separated, a compound of the type M/sub r/X/sub s/ is added to produce a water insoluble sulfate of M and a water insoluble oxide of the metal in the radical X. In the compound M/sub r/X/sub s/, M is at least one metal selected from the group consisting of Ba/sup 2 +/, Ca/sup 2 +/, Sr/sup 2 +/, La/sup 2 +/, and Pb/sup 2 +/; X is at least one radical selected from the group consisting of molybdate (MoO/sub 4//sup 2 -/), tungstate (WO/sub 4//sup 2 -/), and metaborate (BO/sub 2//sup 1 -/); and r and s are either 1, 2, or 3 depending upon the valence of M and X. The precipitated mixture is filtered and heated to a temperature sufficiently high to form SO/sub 3/ gas and to reform M/sub r/X/sub s/. The SO/sub 3/ is dissolved in a small amount of H/sub 2/O to produce concentrated H/sub 2/SO/sub 4/, and the M/sub r/X/sub s/ is recycled to the process. Alternatively, the SO/sub 3/ gas can be recycled to the beginning of the process to provide a continuous process for the production of H/sub 2/ in which only water need be added in a substantial amount. (BLM)

  11. Hydrogen Production Cost Estimate Using Biomass Gasification: Independent Review

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-10-01

    This independent review is the conclusion arrived at from data collection, document reviews, interviews and deliberation from December 2010 through April 2011 and the technical potential of Hydrogen Production Cost Estimate Using Biomass Gasification. The Panel reviewed the current H2A case (Version 2.12, Case 01D) for hydrogen production via biomass gasification and identified four principal components of hydrogen levelized cost: CapEx; feedstock costs; project financing structure; efficiency/hydrogen yield. The panel reexamined the assumptions around these components and arrived at new estimates and approaches that better reflect the current technology and business environments.

  12. Esterification of glycerol from biodiesel production to glycerol carbonate in non-catalytic supercritical dimethyl carbonate.

    Science.gov (United States)

    Ilham, Zul; Saka, Shiro

    2016-01-01

    Conversion of glycerol from biodiesel production to glycerol carbonate was studied by esterification with dimethyl carbonate in a non-catalytic supercritical condition. It was found that in a non-catalytic supercritical condition, glycerol at higher purity gave higher yield of glycerol carbonate at 98 wt% after reaction at 300 °C/20-40 MPa/15 min. The yield of glycerol carbonate was observed to increase with molar ratio, temperature, pressure and time until a certain equilibrium limit. The existence of impurities such as water and remnants of alkaline catalyst in crude glycerol will direct the reaction to produce glycidol. Although impurities might not be desirable, the non-catalytic supercritical dimethyl carbonate could be an alternative method for conversion of glycerol from biodiesel production to value-added glycerol carbonate.Graphical abstractPlausible reaction scheme for conversion of glycerol to glycerol carbonate in non-catalytic supercritical dimethyl carbonate. PMID:27386367

  13. The endogenous production of hydrogen sulphide in intrauterine tissues

    Directory of Open Access Journals (Sweden)

    Wang Rui

    2009-02-01

    Full Text Available Abstract Background Hydrogen sulphide is a gas signalling molecule which is produced endogenously from L-cysteine via the enzymes cystathionine beta-synthase (CBS and cystathionine gamma-lyase (CSE. The possible role of hydrogen sulphide in reproduction has not yet been fully investigated. It has been previously demonstrated that hydrogen sulphide relaxes uterine smooth muscle in vitro. The aim of the present study was to investigate the endogenous production of hydrogen sulphide in rat and human intrauterine tissues in vitro. Methods The production of hydrogen sulphide in rat and human intrauterine tissues was measured in vitro using a standard technique. The expression of CBS and CSE was also investigated in rat and human intrauterine tissues via Western blotting. Furthermore, the effects of nitric oxide (NO and low oxygen conditions on the production rates of hydrogen sulphide were investigated. Results The order of hydrogen sulphide production rates (mean +/- SD, n = 4 for rat tissues were: liver (777 +/- 163 nM/min/g > uterus (168 +/- 100 nM/min/g > fetal membranes (22.3 +/- 15.0 nM/min/g > placenta (11.1 +/- 4.7 nM/min/g, compared to human placenta (200 +/- 102 nM/min/g. NO significantly increased hydrogen sulphide production in rat fetal membranes (P Conclusion Rat and human intrauterine tissues produce hydrogen sulphide in vitro possibly via CBS and CSE enzymes. NO increased the production of hydrogen sulphide in rat fetal membranes. The augmentation of hydrogen sulphide production in human intrauterine tissues in a low oxygen environment could have a role in pathophysiology of pregnancy.

  14. H2 production by catalytic methane decomposition on Cu based catalyst

    International Nuclear Information System (INIS)

    The thermo-catalytic decomposition (TCD) of methane has been investigated in a laboratory scale fixed bed reactor using a copper dispersed on γ-alumina as a catalyst. The usefulness of a fluidized bed operation instead of a fixed bed one has been assessed in terms of methane to hydrogen conversion, amount of carbon accumulated on the catalyst, possibility of the catalyst regeneration. The results highlight some promising features in using fluidized bed reactors in the TCD process. (authors)

  15. Hydrogen production associated to the treatment of nuclear waste

    International Nuclear Information System (INIS)

    The exploitation of nuclear energy produces radioactive waste. However, many radioactive waste treatment processes can be adapted to generate hydrogen as a by-product, thereby helping to further decrease CO2 emissions through the use of hydrogen as an energy vector. Two examples are given: 1) the aggressive decontamination of metallic pieces, and 2) the electro-mediated oxidation of organic radioactive waste. Preliminary results obtained at the SCKxCEN in collaboration with the University of Liege indicate that hydrogen production can often be technically and economically combined with waste treatment, although the hydrogen production rate remains marginal with respect to large-scale water electrolysis. Further R and D work is needed in the field, but the resulting know-how would allow for an increase in the competitiveness of the electrolytic production of hydrogen in general (especially whenever membrane processes are being considered). (authors)

  16. Potential of biogenic hydrogen production for hydrogen driven remediation strategies in marine environments

    OpenAIRE

    Hosseinkhani, Baharak; Hennebel, Tom; Boon, Nico

    2014-01-01

    Fermentative production of bio-hydrogen (bio-H2) from organic residues has emerged as a promising alternative for providing the required electron source for hydrogen driven remediation strategies. Unlike the widely used production of H2 by bacteria in fresh water systems, few reports are available regarding the generation of biogenic H2 and optimisation processes in marine systems. The present research aims to optimise the capability of an indigenous marine bacterium for the production of bio...

  17. Catalytic Hydrogenation of Levulinic Acid in Water into g-Valerolactone over Bulk Structure of Inexpensive Intermetallic Ni-Sn Alloy Catalysts

    Directory of Open Access Journals (Sweden)

    Rodiansono Rodiansono

    2015-07-01

    Full Text Available A bulk structure of inexpensive intermetallic nickel-tin (Ni-Sn alloys catalysts demonstrated highly selective in the hydrogenation of levulinic acid in water into g-valerolactone. The intermetallic Ni-Sn catalysts were synthesized via a very simple thermochemical method from non-organometallic precursor at low temperature followed by hydrogen treatment at 673 K for 90 min. The molar ratio of nickel salt and tin salt was varied to obtain the corresponding Ni/Sn ratio of 4.0, 3.0, 2.0, 1.5, and 0.75. The formation of Ni-Sn alloy species was mainly depended on the composition and temperature of H2 treatment. Intermetallics Ni-Sn that contain Ni3Sn, Ni3Sn2, and Ni3Sn4 alloy phases are known to be effective heterogeneous catalysts for levulinic acid hydrogenation giving very excellence g-valerolactone yield of >99% at 433 K, initial H2 pressure of 4.0 MPa within 6 h. The effective hydrogenation was obtained in H2O without the formation of by-product. Intermetallic Ni-Sn(1.5 that contains Ni3Sn2 alloy species demonstrated very stable and reusable catalyst without any significant loss of its selectivity. © 2015 BCREC UNDIP. All rights reserved. Received: 26th February 2015; Revised: 16th April 2015; Accepted: 22nd April 2015  How to Cite: Rodiansono, R., Astuti, M.D., Ghofur, A., Sembiring, K.C. (2015. Catalytic Hydrogenation of Levulinic Acid in Water into g-Valerolactone over Bulk Structure of Inexpensive Intermetallic Ni-Sn Alloy Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 10 (2: 192-200. (doi:10.9767/bcrec.10.2.8284.192-200Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.8284.192-200  

  18. Effects of hydrogen bonds in association with flavin and substrate in flavoenzyme d-amino acid oxidase. The catalytic and structural roles of Gly313 and Thr317.

    Science.gov (United States)

    Setoyama, Chiaki; Nishina, Yasuzo; Tamaoki, Haruhiko; Mizutani, Hisashi; Miyahara, Ikuko; Hirotsu, Ken; Shiga, Kiyoshi; Miura, Retsu

    2002-01-01

    According to the three-dimensional structure of a porcine kidney D-amino acid oxidase-substrate (D-leucine) complex model, the G313 backbone carbonyl recognizes the substrate amino group by hydrogen bonding and the side-chain hydroxyl of T317 forms a hydrogen bond with C(2)=O of the flavin moiety of FAD [Miura et al. (1997) J. Biochem. 122, 825-833]. We have designed and expressed the G313A and T317A mutants and compared their enzymatic and spectroscopic properties with those of the wild type. The G313A mutant shows decreased activities to various D-amino acids, but the pattern of substrate specificity is different from that of the wild type. The results imply that the hydrogen bond between the G313 backbone carbonyl and the substrate amino group plays important roles in substrate recognition and in defining the substrate specificity of D-amino acid oxidase. The T317A mutant shows a decreased affinity for FAD. The steady-state kinetic measurements indicate diminished activities of T317A to substrate D-amino acids. The transient kinetic parameters measured by stopped-flow spectroscopy revealed that T317 plays key roles in stabilizing the purple intermediate, a requisite intermediate in the oxidative half-reaction, and in enhancing the release of the product from the active site, thereby optimizing the overall catalytic process of D-amino acid oxidase. PMID:11754736

  19. Aqueous-phase catalytic hydrogenation of furfural to cyclopentanol over Cu-Mg-Al hydrotalcites derived catalysts:Model reaction for upgrading of bio-oil

    Institute of Scientific and Technical Information of China (English)

    Minghao; Zhou; Zuo; Zeng; Hongyan; Zhu; Guomin; Xiao; Rui; Xiao

    2014-01-01

    A series of Cu-Mg-Al hydrotalcites derived oxides with a(Cu+Mg)/Al mole ratio of 3 and varied Cu/Mg mole ratio(from 0.07 to 0.30) were prepared by co-precipitation and calcination methods, then they were introduced to the hydrogenation of furfural in aqueous-phase. Effects of Cu/Mg mole ratio, reaction temperature, initial hydrogen pressure, reaction time and catalyst amount on the conversion rate of furfural as well as the selectivity toward desired product cyclopentanol were systematically investigated. The conversion of furfural over calcined hydrotalcite catalyst with a Cu/Mg mole ratio of 0.2 was up to 98.5% when the reaction was carried out under 140 ?C and the initial hydrogen pressure of 4 MPa for 10 h, while the selectivity toward cyclopentanol was up to 94.8%. The catalysts were characterized by XRD and SEM. XRD diffraction of all the samples showed characteristic pattern of hydrotalcite with varied peak intensity as a result of different Cu content. The catalytic activity was improved gradually with the increase of Cu component in the hydrotalcite.

  20. Comparative analysis of hydrogen-producing bacteria and its immobilized cells for characteristics of hydrogen production

    Institute of Scientific and Technical Information of China (English)

    王相晶; 任南琪; 向文胜; 王爱杰; 林明; 郭婉茜

    2003-01-01

    A strain of hydrogen producing bacteria was immobilized by polyvinyl alcohol-boric acid method,with the addition of a small amount of calcium alginate. The immobilized cells were insensitive to the presence of traces of O2. Moreover, the immobilized cells increased both the evolution rate and the yield of hydrogen production. Batch experiments with a medium containing 10 g/L glucose demonstrated the yields of hydrogen production by the immobilized and free cells were 2.14 mol/mol glucose and 1.69 mol/mol glucose, respectively.In continuous cultures atmedium retention time of 2. 0 h, the yield and the evolution rate of hydrogen producmedium retention time of 6. 0 h, the yield and the evolution rate of hydrogen production by free cells were only 1.75 mol/mol glucose and 362.9ml/(L·h),respectively.

  1. 对苯二甲酸催化加氢的Ru-Sn-B/丝光沸石催化性能%Catalytic performance of Ru-Sn-B/mordenite for terephthalic acid catalytic hydrogenation

    Institute of Scientific and Technical Information of China (English)

    赵葛新; 靳海波; 何广湘; 郭志武; 杨索和

    2012-01-01

    采用分步浸渍和化学还原的方法制备以丝光沸石分子筛为载体的Ru-Sn-B催化剂,研究了在负载型催化剂Ru-Sn-B/丝光沸石上对苯二甲酸催化加氢制备1,4-环己烷二甲醇的加氢催化性能,并利用XRD和BET等分析手段对Ru-Sn-B/丝光沸石催化剂进行表征.结果 表明,RuB和Sn在丝光沸石上具有较好的分散性,Ru-Sn-B/丝光沸石催化剂具有较高的催化活性和选择性;催化加氢过程中采用两段升温升压的方法,对苯二甲酸转化率约100%,产物1,4-环己烷二甲醇的收率为73.5%,反式与顺式之比为2.42.%Ru-Sn-B/mordenite catalysts were prepared by sequential impregnation and chemical reduction methods and using mordenite zeolite as the carrier. The catalytic performance of Ru-Sn-B/mordenite catalysts for terephthalic acid hydrogenation to 1,4-cyclohexanedimethanol was investigated. The as-prepared catalysts were characterized by XRD, BET, EDS and ICP. The results showed that RuB and Sn had better dispersion on the mordenite, and Ru-Sn-B/mordenite catalyst possessed high catalytic activity and selectivity. The catalytic hydrogenation process used two stage enhancement method of temperature and pressure. Terephthalic acid conversion rate of about 100% ,the yield of the product 1,4-cyclohexanedimethanol of 73.5% ,and the ratio of trans and cis of the product of 2.42 were attained,respectively.

  2. Selective Catalytic Oxidation of Hydrogen Sulfide to Elemental Sulfur from Coal-Derived Fuel Gases

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, Todd H.; Berry, David A.; Lyons, K. David; Beer, Stephen K.; Monahan, Michael J.

    2001-11-06

    The development of low cost, highly efficient, desulfurization technology with integrated sulfur recovery remains a principle barrier issue for Vision 21 integrated gasification combined cycle (IGCC) power generation plants. In this plan, the U. S. Department of Energy will construct ultra-clean, modular, co-production IGCC power plants each with chemical products tailored to meet the demands of specific regional markets. The catalysts employed in these co-production modules, for example water-gas-shift and Fischer-Tropsch catalysts, are readily poisoned by hydrogen sulfide (H{sub 2}S), a sulfur contaminant, present in the coal-derived fuel gases. To prevent poisoning of these catalysts, the removal of H{sub 2}S down to the parts-per-billion level is necessary. Historically, research into the purification of coal-derived fuel gases has focused on dry technologies that offer the prospect of higher combined cycle efficiencies as well as improved thermal integration with co-production modules. Primarily, these concepts rely on a highly selective process separation step to remove low concentrations of H{sub 2}S present in the fuel gases and produce a concentrated stream of sulfur bearing effluent. This effluent must then undergo further processing to be converted to its final form, usually elemental sulfur. Ultimately, desulfurization of coal-derived fuel gases may cost as much as 15% of the total fixed capital investment (Chen et al., 1992). It is, therefore, desirable to develop new technology that can accomplish H{sub 2}S separation and direct conversion to elemental sulfur more efficiently and with a lower initial fixed capital investment.

  3. Passive auto-catalytic recombiners operation in the presence of hydrogen and carbon monoxide: Experimental study and model development

    Energy Technology Data Exchange (ETDEWEB)

    Klauck, Michael, E-mail: klauck@lrst.rwth-aachen.de [RWTH Aachen University, Institute for Reactor Safety and Reactor Technology, 52072 Aachen (Germany); Reinecke, Ernst-Arndt, E-mail: e.reinecke@fz-juelich.de [Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Nuclear Waste Management and Reactor Safety (IEK-6), 52425 Jülich (Germany); Kelm, Stephan, E-mail: s.kelm@fz-juelich.de [Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Nuclear Waste Management and Reactor Safety (IEK-6), 52425 Jülich (Germany); Meynet, Nicolas, E-mail: nicolas.meynet@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES/SAG/BPhAG, BP 17 92262 Fontenay aux Roses (France); Bentaïb, Ahmed, E-mail: ahmed.bentaib@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES/SAG/BPhAG, BP 17 92262 Fontenay aux Roses (France); Allelein, Hans-Josef, E-mail: allelein@lrst.rwth-aachen.de [RWTH Aachen University, Institute for Reactor Safety and Reactor Technology, 52072 Aachen (Germany); Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Nuclear Waste Management and Reactor Safety (IEK-6), 52425 Jülich (Germany)

    2014-01-15

    Highlights: • We studied the hydrogen conversion in the presence of carbon monoxide (CO). • CO recombines at a lower efficiency than hydrogen. • Under the given conditions, hydrogen conversion is not affected by CO. • We used three different numerical codes to simulate the experimental findings. • All codes are reproducing the experimental data well. -- Abstract: In a LWR severe accident, carbon monoxide (CO) may be generated inside the containment due to molten corium concrete interaction (MCCI). As a component of the accident atmosphere, CO will interact with passive auto-catalytic recombiners (PARs) which are installed inside LWR containments for hydrogen (H{sub 2}) removal. Depending on the boundary conditions, CO may either react with oxygen to carbon dioxide (CO{sub 2}) or act as catalyst poison, reducing the catalyst activity and hence the hydrogen conversion efficiency. A new experimental test programme performed in co-operation between JÜLICH and RWTH investigates these aspects aiming at providing data for model development for advanced severe accident analyses. In the first test series presented here, the parallel catalytic reaction of H{sub 2} and CO on the catalyst surface has been studied, i.e. the hydrogen recombination reaction was started before CO was injected. In total, 33 steady state measurements have been performed. The test series was jointly evaluated by JÜLICH, RWTH and IRSN. The test results show that under the given conditions the conversion of CO into CO{sub 2} has no negative impact on the parallel hydrogen conversion. The efficiency of the CO recombination in terms of molar rates is significantly smaller (by a factor of ∼2) than the corresponding H{sub 2} conversion efficiency. Due to the exothermal reaction, the parallel CO conversion may also have an impact on the possible ignition of the flammable gases at hot PAR surfaces. The authors have used three different numerical codes for the simulation of the parallel CO

  4. Positive aspects issued from bio-corrosion studies: from hydrogen production to biofuel cells

    International Nuclear Information System (INIS)

    Microbially influenced corrosion or bio-corrosion is a problem that generates heavy global economic losses (several billion euros per year). In spite of the progress made on the understanding of the underlying mechanisms, the complexity of the phenomenon has prevented finding definitive solutions to the problem and continues to inspire many research works. The participation in bio-corrosion of catalytic mechanisms induced by weak acids was studied in this work. Another objective of the thesis has been to take advantage from catalytic phenomena found in bio corrosion research to apply them in other areas: energy production with biofuel cells or electrochemical hydrogen production in mild conditions. This work has shown that the presence of weak acids and amino acids inside bio films could play a major role in steel bio-corrosion accelerating the phenomenon through the catalysis of the water reduction reaction. The reversibility of this mechanism, discerned and proved here, could explain the corrosion increase when hydrogen is removed (bacterial consumption, agitation...). In addition, phosphates allow the production of hydrogen by electrolysis in mild ph conditions (pH 4.0 - 8.0) with an equal or better performance than those found in alkaline electrolysis. Finally, industrial materials like stainless steel and titanium could be used in the fabrication of enzymatic electrodes for biosensors or microsystems. The use of the glucose oxidase / glucose system in an aqueous fuel cell with a stainless steel cathode, allows the improvement of the cell performance thanks to the production of hydrogen peroxide that is easily reduced. Moreover, the use of materials with micro-structured surfaces like sandblasted steels deserve to be studied in detail to exploit the remarkable reactivity they present compared to smooth electrodes. (author)

  5. Positive aspects issued from bio corrosion studies: from hydrogen production to biofuel cells

    International Nuclear Information System (INIS)

    Microbially influenced corrosion or bio corrosion is a problem that generates heavy global economic losses (several billion euros per year). In spite of the progress made on the understanding of the underlying mechanisms, the complexity of the phenomenon has prevented finding definitive solutions to the problem and continues to inspire many research works. The participation in bio corrosion of catalytic mechanisms induced by weak acids was studied in this work. Another objective of the thesis has been to take advantage from catalytic phenomena found in bio corrosion research to apply them in other areas: energy production with biofuel cells or electrochemical hydrogen production in mild conditions. This work has shown that the presence of weak acids and amino acids inside bio-films could play a major role in steel bio corrosion accelerating the phenomenon through the catalysis of the water reduction reaction. The reversibility of this mechanism, discerned and proved here, could explain the corrosion increase when hydrogen is removed (bacterial consumption, agitation...). In addition, phosphates allow the production of hydrogen by electrolysis in mild pH conditions (pH 4.0 - 8.0) with an equal or better performance than those found in alkaline electrolysis. Finally, industrial materials like stainless steel and titanium could be used in the fabrication of enzymatic electrodes for biosensors or microsystems. The use of the glucose oxidase/glucose system in an aqueous fuel cell with a stainless steel cathode, allows the improvement of the cell performance thanks to the production of hydrogen peroxide that is easily reduced. Moreover, the use of materials with micro-structured surfaces like sandblasted steels deserve to be studied in detail to exploit the remarkable reactivity they present compared to smooth electrodes. (author)

  6. Hydrogen production using high temperature nuclear reactors : A feasibility study

    OpenAIRE

    Sivertsson, Viktor

    2010-01-01

    The use of hydrogen is predicted to increase substantially in the future, both as chemical feedstock and also as energy carrier for transportation. The annual world production of hydrogen amounts to some 50 million tonnes and the majority is produced using fossil fuels like natural gas, coal and naphtha. High temperature nuclear reactors (HTRs) represent a novel way to produce hydrogen at large scale with high efficiency and less carbon footprint. The aim of this master thesis has been to eva...

  7. Cost Analysis of a Concentrator Photovoltaic Hydrogen Production System

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J. R.; McConnell, R. D.; Mosleh, M.

    2005-08-01

    The development of efficient, renewable methods of producing hydrogen are essential for the success of the hydrogen economy. Since the feedstock for electrolysis is water, there are no harmful pollutants emitted during the use of the fuel. Furthermore, it has become evident that concentrator photovoltaic (CPV) systems have a number of unique attributes that could shortcut the development process, and increase the efficiency of hydrogen production to a point where economics will then drive the commercial development to mass scale.

  8. Microbiological Hydrogen Production by Anaerobic Fermentation and Photosynthetic Process

    Energy Technology Data Exchange (ETDEWEB)

    Asada, Y.; Ohsawa, M.; Nagai, Y.; Fukatsu, M.; Ishimi, K.; Ichi-ishi, S.

    2009-07-01

    Hydrogen gas is a clean and renewable energy carrier. Microbiological hydrogen production from glucose or starch by combination used of an anaerobic fermenter and a photosynthetic bacterium, Rhodobacter spheroides RV was studied. In 1984, the co-culture of Clostridium butyricum and RV strain to convert glucose to hydrogen was demonstrated by Miyake et al. Recently, we studied anaerobic fermentation of starch by a thermophilic archaea. (Author)

  9. Hydrogen production from dimethyl ether using corona discharge plasma

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Ji-Jun; Liu, Chang-Jun [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Zhang, Yue-Ping [Department of Chemistry, Tianjin University, Tianjin 300072 (China)

    2007-01-01

    Dimethyl ether (DME), with its non-toxic character, high H/C ratio and high-energy volumetric density, is an ideal resource for hydrogen production. In this work, hydrogen production from the decomposition of DME using corona discharge has been studied. The corona discharge plasma decomposition was conducted at ambient conditions. The effects of dilution gas (argon), flow rate, frequency and waveforms on the DME decomposition were investigated. The addition of dilution gas can significantly increase the hydrogen production rate. The highest hydrogen production rate with the lowest energy consumption presents at the flow rate of 27.5Nmlmin{sup -1}. AC voltage is more favored than DC voltage for the production of hydrogen with less energy input. The optimal frequency is 2.0kHz. The hydrogen production rate is also affected by the input waveform and decreases as following: sinusoid triangular>sinusoid>ramp>square, whereas the sinusoid waveform shows the highest energy efficiency. The corona discharge decomposition of DME is leading to a simple, easy and convenient hydrogen production with no needs of catalyst and external heating. (author)

  10. Hydrogen production from glucose by anaerobes.

    Science.gov (United States)

    Ogino, Hiroyasu; Miura, Takashi; Ishimi, Kosaku; Seki, Minoru; Yoshida, Hiroyuki

    2005-01-01

    Various anaerobes were cultivated in media containing glucose. When 100 mL of thioglycollate medium containing 2.0% (w/v) glucose was used, Clostridium butyricum ATCC 859, NBRC 3315, and NBRC 13949 evolved 227-243 mL of biogas containing about 180 mL of hydrogen in 1 day. Although some strains had some resistance against oxygen, C. butyricum ATCC 859 and 860 did not have it. C. butyricum NBRC 3315 and Enterobacter aerogenes NBRC 13534 produced hydrogen in the presence of glucose or pyruvic acid, and E. aerogenes NBRC 13534 produced hydrogen by not only glucose and pyruvic acid but also dextrin, sucrose, maltose, galactose, fructose, mannose, and mannitol. When a medium containing 0.5% (w/v) yeast extract and 2.0% (w/v) glucose was used, E. aerogenes NBRC 13534 evolved more biogas and hydrogen than C. butyricum NBRC 3315 in the absence of reducing agent.

  11. Production of bioplastics and hydrogen gas by photosynthetic microorganisms

    Science.gov (United States)

    Yasuo, Asada; Masato, Miyake; Jun, Miyake

    1998-03-01

    Our efforts have been aimed at the technological basis of photosynthetic-microbial production of materials and an energy carrier. We report here accumulation of poly-(3-hydroxybutyrate) (PHB), a raw material of biodegradable plastics and for production of hydrogen gas, and a renewable energy carrier by photosynthetic microorganisms (tentatively defined as cyanobacteria plus photosynthetic bateria, in this report). A thermophilic cyanobacterium, Synechococcus sp. MA19 that accumulates PHB at more than 20% of cell dry wt under nitrogen-starved conditions was isolated and microbiologically identified. The mechanism of PHB accumulation was studied. A mesophilic Synechococcus PCC7942 was transformed with the genes encoding PHB-synthesizing enzymes from Alcaligenes eutrophus. The transformant accumulated PHB under nitrogen-starved conditions. The optimal conditions for PHB accumulation by a photosynthetic bacterium grown on acetate were studied. Hydrogen production by photosynthetic microorganisms was studied. Cyanobacteria can produce hydrogen gas by nitrogenase or hydrogenase. Hydrogen production mediated by native hydrogenase in cyanobacteria was revealed to be in the dark anaerobic degradation of intracellular glycogen. A new system for light-dependent hydrogen production was targeted. In vitro and in vivo coupling of cyanobacterial ferredoxin with a heterologous hydrogenase was shown to produce hydrogen under light conditions. A trial for genetic trasformation of Synechococcus PCC7942 with the hydrogenase gene from Clostridium pasteurianum is going on. The strong hydrogen producers among photosynthetic bacteria were isolated and characterized. Co-culture of Rhodobacter and Clostriumdium was applied to produce hydrogen from glucose. Conversely in the case of cyanobacteria, genetic regulation of photosynthetic proteins was intended to improve conversion efficiency in hydrogen production by the photosynthetic bacterium, Rhodobacter sphaeroides RV. A mutant acquired by

  12. Potential application of anaerobic extremophiles for hydrogen production

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.

    2004-11-01

    In processes of the substrate fermentation most anaerobes produce molecular hydrogen as a waste end product, which often controls the culture growth as an inhibitor. Usually in nature the hydrogen is easily removed from an ecosystem, due to its physical features, and an immediate consumption by the secondary anaerobes that sometimes behave as competitors for electron donors; a classical example of this kind of substrate competition in anaerobic microbial communities is the interaction between methanogens and sulfate- or sulfur-reducers. Previously, on the mixed cultures of anaerobes at neutral pH, it was demonstrated that bacterial hydrogen production could provide a good alternative energy source. At neutral pH the original cultures could easily contaminated by methanogens, and the most unpleasant side effect of these conditions is the development of pathogenic bacteria. In both cases the rate of hydrogen production was dramatically decreased since some part of the hydrogen was transformed to methane, and furthermore, the cultivation with pathogenic contaminants on an industrial scale would create an unsafe situation. In our laboratory the experiments with obligately alkaliphilic bacteria producing hydrogen as an end metabolic product were performed at different conditions. The mesophilic, haloalkaliphilic and obligately anaerobic bacterium Spirochaeta americana ASpG1T was studied and various cultivation regimes were compared for the most effective hydrogen production. In a highly mineralized media with pH 9.5-10.0 not many known methanogens are capable of growth, and the probability of developing pathogenic contaminants is theoretically is close to zero (in medicine carbonate- saturated solutions are applied as antiseptics). Therefore the cultivation of alkaliphilic hydrogen producing bacteria could be considered as a safe and economical process for large-scale industrial bio-hydrogen production in the future. Here we present and discuss the experimental data

  13. Electrolytic production and dispensing of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.E.; Kuhn, I.F. Jr. [Directed Technologies, Inc., Arlington, VA (United States)

    1995-09-01

    The fuel cell electric vehicle (FCEV) is undoubtedly the only option that can meet both the California zero emission vehicle (ZEV) standard and the President`s goal of tripling automobile efficiency without sacrificing performance in a standard 5-passenger vehicle. The three major automobile companies are designing and developing FCEVs powered directly by hydrogen under cost-shared contracts with the Department of Energy. Once developed, these vehicles will need a reliable and inexpensive source of hydrogen. Steam reforming of natural gas would produce the least expensive hydrogen, but funding may not be sufficient initially to build both large steam reforming plants and the transportation infrastructure necessary to deliver that hydrogen to geographically scattered FCEV fleets or individual drivers. This analysis evaluates the economic feasibility of using small scale water electrolysis to provide widely dispersed but cost-effective hydrogen for early FCEV demonstrations. We estimate the cost of manufacturing a complete electrolysis system in large quantities, including compression and storage, and show that electrolytic hydrogen could be cost competitive with fully taxed gasoline, using existing residential off-peak electricity rates.

  14. Nano cobalt oxides for photocatalytic hydrogen production

    KAUST Repository

    Mangrulkar, Priti A.

    2012-07-01

    Nano structured metal oxides including TiO 2, Co 3O 4 and Fe 3O 4 have been synthesized and evaluated for their photocatalytic activity for hydrogen generation. The photocatalytic activity of nano cobalt oxide was then compared with two other nano structured metal oxides namely TiO 2 and Fe 3O 4. The synthesized nano cobalt oxide was characterized thoroughly with respect to EDX and TEM. The yield of hydrogen was observed to be 900, 2000 and 8275 mmol h -1 g -1 of photocatalyst for TiO 2, Co 3O 4 and Fe 3O 4 respectively under visible light. It was observed that the hydrogen yield in case of nano cobalt oxide was more than twice to that of TiO 2 and the hydrogen yield of nano Fe 3O 4 was nearly four times as compared to nano Co 3O 4. The influence of various operating parameters in hydrogen generation by nano cobalt oxide was then studied in detail. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  15. Hydrogen generation from catalytic hydrolysis of sodium borohydride solution using Cobalt-Copper-Boride (Co-Cu-B) catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Xin-Long; Yuan, Xianxia; Jia, Chao; Ma, Zi-Feng [Department of Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2010-10-15

    Co-Cu-B, as a catalyst toward hydrolysis of sodium borohydride solution, has been prepared through chemical reduction of metal salts, CoCl{sub 2}.6H{sub 2}O and CuCl{sub 2}, by an alkaline solution composed of 7.5wt% NaBH{sub 4} and 7.5wt% NaOH. The effects of Co/Cu molar ratio, calcination temperature, NaOH and NaBH{sub 4} concentration and reaction temperature on catalytic activity of Co-Cu-B for hydrogen generation from alkaline NaBH{sub 4} solution have been studied. X-ray diffraction (XRD), scanning electron microscope (SEM) and Nitrogen adsorption-desorption isotherm have been employed to understand the results. The Co-Cu-B catalyst with a Co/Cu molar ratio of 3:1 and calcinated at 400 C showed the best catalytic activity at ambient temperature. The activation energy of this catalytic reaction is calculated to be 49.6 kJ mol{sup -1}. (author)

  16. A General Catalytic Enantioselective Transfer Hydrogenation Reaction of β,β-Disubstituted Nitroalkenes Promoted by a Simple Organocatalyst.

    Science.gov (United States)

    Bernardi, Luca; Fochi, Mariafrancesca

    2016-01-01

    Given its synthetic relevance, the catalytic enantioselective reduction of β,β-disubstituted nitroalkenes has received a great deal of attention. Several bio-, metal-, and organo-catalytic methods have been developed, which however are usually applicable to single classes of nitroalkene substrates. In this paper, we present an account of our previous work on this transformation, which implemented with new disclosures and mechanistic insights results in a very general protocol for nitroalkene reductions. The proposed methodology is characterized by (i) a remarkably broad scope encompassing various nitroalkene classes; (ii) Hantzsch esters as convenient (on a preparative scale) hydrogen surrogates; (iii) a simple and commercially available thiourea as catalyst; (iv) user-friendly procedures. Overall, the proposed protocol gives a practical dimension to the catalytic enantioselective reduction of β,β-disubstituted nitroalkenes, offering a useful and general platform for the preparation of nitroalkanes bearing a stereogenic center at the β-position in a highly enantioenriched form. A transition state model derived from control kinetic experiments combined with literature data is proposed and discussed. This model accounts and justifies the observed experimental results. PMID:27483233

  17. Simulation of a hydrogen production and purification system for a PEM fuel-cell using bioethanol as raw material

    Energy Technology Data Exchange (ETDEWEB)

    Giunta, Pablo; Amadeo, Norma; Laborde, Miguel [Facultad de Ingenieria, Universidad de Buenos Aires, Laboratorio de Procesos Cataliticos, Pabellon de Industrias, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Mosquera, Carlos [Facultad de Ingenieria, Universidad de Buenos Aires, Departamento de Fisica, 1063 Buenos Aires (Argentina)

    2007-01-10

    A process to produce 'fuel-cell grade' hydrogen from ethanol steam reforming is analyzed from a thermodynamic point of view. The hydrogen purification process consists of WGS and COPROX reactors. Equations to evaluate the efficiency of the system, including the fuel cell, are presented. A heat exchange network is proposed in order to improve the exploitation of the available power. The effect of key variables such as the reformer temperature and the ethanol/water molar feed ratio on the fuel-cell efficiency is discussed. Results show that it is feasible to carry out the energy integration of the hydrogen catalytic production and purification-PEM fuel-cell system, using ethanol as raw material. The technology of 'fuel-cell grade' hydrogen production using ethanol as raw material is a very attractive alternative to those technologies based in fossil fuels. (author)

  18. Estimation of bacterial hydrogen sulfide production in vitro

    Directory of Open Access Journals (Sweden)

    Amina Basic

    2015-06-01

    Full Text Available Oral bacterial hydrogen sulfide (H2S production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways.

  19. Improvements in Fermentative Biological Hydrogen Production Through Metabolic Engineering

    International Nuclear Information System (INIS)

    Dramatically rising oil prices and increasing awareness of the dire environmental consequences of fossil fuel use, including startling effects of climate change, are refocusing attention world-wide on the search for alternative fuels. Hydrogen is poised to become an important future energy carrier. Renewable hydrogen production is pivotal in making it a truly sustainable replacement for fossil fuels. (Author)

  20. Technical suitability mapping of feedstocks for biological hydrogen production

    NARCIS (Netherlands)

    Panagiotopoulos, I.A.; Karaoglanoglou, L.S.; Koullas, D.P.; Bakker, R.R.; Claassen, P.A.M.; Koukios, E.G.

    2015-01-01

    The objective of this work was to map and compare the technical suitability of different raw materials for biological hydrogen production. Our model was based on hydrogen yield potential, sugar mobilization efficiency, fermentability and coproduct yield and value. The suitability of the studied r

  1. Bibliographic Review about Solar Hydrogen Production Through Thermochemical Cycles

    International Nuclear Information System (INIS)

    This report presents a summary of the different thermical processes used to obtain hydrogen through solar energy, paying more attention to the production of hydrogen from water through thermochemical cycles. In this aspect, it is briefly described the most interesting thermochemical cycles, focusing on thermochemical cycles based on oxides. (Author) 25 refs

  2. Improvements in Fermentative Biological Hydrogen Production Through Metabolic Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hallenbeck, P. C.; Ghosh, D.; Sabourin-Provost, G.

    2009-07-01

    Dramatically rising oil prices and increasing awareness of the dire environmental consequences of fossil fuel use, including startling effects of climate change, are refocusing attention world-wide on the search for alternative fuels. Hydrogen is poised to become an important future energy carrier. Renewable hydrogen production is pivotal in making it a truly sustainable replacement for fossil fuels. (Author)

  3. Potential Application of Anaerobic Extremophiles for Hydrogen Production

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.

    2004-01-01

    During substrate fermentation many anaerobes produce the hydrogen as a waste product, which often regulates the growth of the cultures as an inhibitor. In nature the hydrogen is usually removed from the ecosystem due to its physical properties or by consumption of hydrogen by secondary anaerobes, which sometimes behave as competitors for electron donors as is seen in the classical example in anaerobic microbial communities via the interaction between methanogens and sulfate- or sulfur- reducers. It was demonstrated previously on mixed cultures of anaerobes at neutral pH that bacterial hydrogen production could provide an alternative energy source. But at neutral pH the original cultures can easily be contaminated by methanogens, a most unpleasant side effect of these conditions is the development of pathogenic bacteria. In both cases the rate of hydrogen production was dramatically decreased since some part of the hydrogen was transformed to methane, and the cultivation of human pathogens on a global scale is very dangerous. In our laboratory, experiments with obligately alkaliphilic bacteria that excrete hydrogen as the end metabolic product were performed at different temperature regimes. Mesophilic and moderately thermophilic bacterial cultures have been studied and compared for the most effective hydrogen production. For high-mineralized media with pH 9.5-10.0 not many methanogens are known to exist. Furthermore, the development of pathogenic contaminant microorganisms is virtually impossible: carbonate-saturated solutions are used as antiseptics in medicine. Therefore the cultivation of alkaliphilic hydrogen producing bacteria could be considered as most safe process for global Scale industry in future. Here we present experimental data on the rates of hydrogen productivity for mesophilic, alkaliphilic, obligately anaerobic bacterium Spirocheta americana ASpG1 and moderately thermophilic, alkaliphilic, facultative anaerobe Anoxybacillus pushchinoensis K1 and

  4. Catalytic oxidative desulfurization of diesel utilizing hydrogen peroxide and functionalized-activated carbon in a biphasic diesel-acetonitrile system

    Energy Technology Data Exchange (ETDEWEB)

    Haw, Kok-Giap; Bakar, Wan Azelee Wan Abu; Ali, Rusmidah; Chong, Jiunn-Fat [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Kadir, Abdul Aziz Abdul [Department of Petroleum Engineering, Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

    2010-09-15

    This paper presents the development of granular functionalized-activated carbon as catalysts in the catalytic oxidative desulfurization (Cat-ODS) of commercial Malaysian diesel using hydrogen peroxide as oxidant. Granular functionalized-activated carbon was prepared from oil palm shell using phosphoric acid activation method and carbonized at 500 C and 700 C for 1 h. The activated carbons were characterized using various analytical techniques to study the chemistry underlying the preparation and calcination treatment. Nitrogen adsorption/desorption isotherms exhibited the characteristic of microporous structure with some contribution of mesopore property. The Fourier Transform Infrared Spectroscopy results showed that higher activation temperature leads to fewer surface functional groups due to thermal decomposition. Micrograph from Field Emission Scanning Electron Microscope showed that activation at 700 C creates orderly and well developed pores. Furthermore, X-ray Diffraction patterns revealed that pyrolysis has converted crystalline cellulose structure of oil palm shell to amorphous carbon structure. The influence of the reaction temperature, the oxidation duration, the solvent, and the oxidant/sulfur molar ratio were examined. The rates of the catalytic oxidative desulfurization reaction were found to increase with the temperature, and H{sub 2}O{sub 2}/S molar ratio. Under the best operating condition for the catalytic oxidative desulfurization: temperature 50 C, atmospheric pressure, 0.5 g activated carbon, 3 mol ratio of hydrogen peroxide to sulfur, 2 mol ratio of acetic acid to sulfur, 3 oxidation cycles with 1 h for each cycle using acetonitrile as extraction solvent, the sulfur content in diesel was reduced from 2189 ppm to 190 ppm with 91.3% of total sulfur removed. (author)

  5. Production of hydrogen from CH{sub 4}, CO or H{sub 2}S in gliding electric discharges

    Energy Technology Data Exchange (ETDEWEB)

    Czernichowski, A. [GlidArc Technologies Sarl, Orleans (France)

    2000-05-01

    A newly developed method to extract hydrogen from natural gas or biogas through pyrolysis or reforming into synthesis gas was presented. The new method, which is more energy efficient and environmentally friendly compared to classical hydrogen production technologies, uses a powerful and extremely active non-thermal plasma source called GlidArc. GlidArc refers to multiple gliding electric discharges. The method is ideally suited for hydrogen production from light hydrocarbons, any methane or carbon dioxide mixtures, gases containing carbon monoxide or waste acid gases containing hydrogen sulphide. These non-equilibrium discharges act as an enthalpy and or catalytic activation source. This paper presented examples of the following: (1) pyrolysis of natural gas, (2) hydrogen from synthesis gas, (3) GlidArc assisted steam reforming of methane, (4) GlidArc assisted partial oxidation of methane, (5) hydrogen production via water shift of carbon monoxide and (6) hydrogen extraction from hydrogen sulphide. The energy balances in each situation demonstrate that up to 40 per cent of input electric energy goes directly into endothermic processes without the use of a catalyst. GlidArc can be easily integrated into nearly any process and is very compact for easy installation in restricted areas. The GlidArc 1 reactor is patented by both U.S. and French patents. Patent is pending on the new GlidArc-II reactor which is better adapted for natural gas and other gas processing. 14 refs., 1 tab., 2 figs.

  6. Rational Design of Porous Conjugated Polymers and Roles of Residual Palladium for Photocatalytic Hydrogen Production.

    Science.gov (United States)

    Li, Lianwei; Cai, Zhengxu; Wu, Qinghe; Lo, Wai-Yip; Zhang, Na; Chen, Lin X; Yu, Luping

    2016-06-22

    Developing highly efficient photocatalyts for water splitting is one of the grand challenges in solar energy conversion. Here, we report the rational design and synthesis of porous conjugated polymer (PCP) that photocatalytically generates hydrogen from water splitting. The design mimics natural photosynthetics systems with conjugated polymer component to harvest photons and the transition metal part to facilitate catalytic activities. A series of PCPs have been synthesized with different light harvesting chromophores and transition metal binding bipyridyl (bpy) sites. The photocatalytic activity of these bpy-containing PCPs can be greatly enhanced due to the improved light absorption, better wettability, local ordering structure, and the improved charge separation process. The PCP made of strong and fully conjugated donor chromophore DBD (M4) shows the highest hydrogen production rate at ∼33 μmol/h. The results indicate that copolymerization between a strong electron donor and weak electron acceptor into the same polymer chain is a useful strategy for developing efficient photocatalysts. This study also reveals that the residual palladium in the PCP networks plays a key role for the catalytic performance. The hydrogen generation activity of PCP photocatalyst can be further enhanced to 164 μmol/h with an apparent quantum yield of 1.8% at 350 nm by loading 2 wt % of extra platinum cocatalyst.

  7. Rational Design of Porous Conjugated Polymers and Roles of Residual Palladium for Photocatalytic Hydrogen Production.

    Science.gov (United States)

    Li, Lianwei; Cai, Zhengxu; Wu, Qinghe; Lo, Wai-Yip; Zhang, Na; Chen, Lin X; Yu, Luping

    2016-06-22

    Developing highly efficient photocatalyts for water splitting is one of the grand challenges in solar energy conversion. Here, we report the rational design and synthesis of porous conjugated polymer (PCP) that photocatalytically generates hydrogen from water splitting. The design mimics natural photosynthetics systems with conjugated polymer component to harvest photons and the transition metal part to facilitate catalytic activities. A series of PCPs have been synthesized with different light harvesting chromophores and transition metal binding bipyridyl (bpy) sites. The photocatalytic activity of these bpy-containing PCPs can be greatly enhanced due to the improved light absorption, better wettability, local ordering structure, and the improved charge separation process. The PCP made of strong and fully conjugated donor chromophore DBD (M4) shows the highest hydrogen production rate at ∼33 μmol/h. The results indicate that copolymerization between a strong electron donor and weak electron acceptor into the same polymer chain is a useful strategy for developing efficient photocatalysts. This study also reveals that the residual palladium in the PCP networks plays a key role for the catalytic performance. The hydrogen generation activity of PCP photocatalyst can be further enhanced to 164 μmol/h with an apparent quantum yield of 1.8% at 350 nm by loading 2 wt % of extra platinum cocatalyst. PMID:27254306

  8. Prospect of HTGRs for hydrogen production in Indonesia

    International Nuclear Information System (INIS)

    Hydrogen energy system is interesting to many people of the world that because of hydrogen promised to save our planet earth from destroying of burning of fossil fuels. The selected development of hydrogen production from water such as electrolysis and thermochemical cycles are evaluated. These processes are allowed to split the water at lower temperature, still in the range of HTGRs' working temperature. An overview of related studies in recent years enables the development of research to be followed, studied and evaluated are mentioned. The prospect of hydrogen market in Indonesia and economic consideration based on previous studied are also analyzed and evaluated. (author). 11 refs, 5 figs, 13 tabs

  9. Utilization of solar energy for the production of hydrogen

    Science.gov (United States)

    Steeb, H.; Kleinkauf, W.; Mehrmann, A.

    1983-09-01

    The combination of photovoltaic solar generators and electrolyzers for hydrogen production was investigated. Two different small solar-hydrogen systems are described. The coupling of photovoltaics and electrolysis; the mode of operation of a unit for power processing; and practical operation experiences are discussed. The proposed active electronic adaptation unit can improve photovoltaic electrolyse systems. Solar energy can be converted into the energy carrier hydrogen with a total yearly average efficiency of 16%. This corresponds to 23 Ncum hydrogen per sqm active solar cell surface for a yearly radiation of 1000 kWh/sqm.

  10. Hydrogen production econometric studies. [hydrogen and fossil fuels

    Science.gov (United States)

    Howell, J. R.; Bannerot, R. B.

    1975-01-01

    The current assessments of fossil fuel resources in the United States were examined, and predictions of the maximum and minimum lifetimes of recoverable resources according to these assessments are presented. In addition, current rates of production in quads/year for the fossil fuels were determined from the literature. Where possible, costs of energy, location of reserves, and remaining time before these reserves are exhausted are given. Limitations that appear to hinder complete development of each energy source are outlined.

  11. Summary of research on hydrogen production from fossil fuels conducted at NETL

    Energy Technology Data Exchange (ETDEWEB)

    Shamsi, Abolghasem

    2008-03-30

    In this presentation we will summarize the work performed at NETL on the production of hydrogen via partial oxidation/dry reforming of methane and catalytic decomposition of hydrogen sulfide. We have determined that high pressure resulted in greater carbon formation on the reforming catalysts, lower methane and CO2 conversions, as well as a H2/CO ratio. The results also showed that Rh/alumina catalyst is the most resistant toward carbon deposition both at lower and at higher pressures. We studied the catalytic partial oxidation of methane over Ni-MgO solid solutions supported on metal foams and the results showed that the foam-supported catalysts reach near-equilibrium conversions of methane and H2/CO selectivities. The rates of carbon deposition differ greatly among the catalysts, varying from 0.24 mg C/g cat h for the dipped foams to 7.0 mg C/g cat h for the powder-coated foams, suggesting that the exposed Cr on all of the foam samples may interact with the Ni-MgO catalyst to kinetically limit carbon formation. Effects of sulfur poisoning on reforming catalysts were studies and pulse sulfidation of catalyst appeared to be reversible for some of the catalysts but not for all. Under pulse sulfidation conditions, the 0.5%Rh/alumina and NiMg2Ox-1100ºC (solid solution) catalysts were fully regenerated after reduction with hydrogen. Rh catalyst showed the best overall activity, less carbon deposition, both fresh and when it was exposed to pulses of H2S. Sulfidation under steady state conditions significantly reduced catalyst activity. Decomposition of hydrogen sulfide into hydrogen and sulfur was studied over several supported metal oxides and metal oxide catalysts at a temperature range of 650-850°C. H2S conversions and effective activation energies were estimated using Arrhenius plots. The results of these studies will further our understanding of catalytic reactions and may help in developing better and robust catalysts for the production of hydrogen from fossil

  12. Hydrogen logistics: Assessment of production, conditioning, distribution, storage and refuelling

    Energy Technology Data Exchange (ETDEWEB)

    Hohlein, B.; Reijerkerk, J.

    2005-07-01

    Providing energy on a clean, safe and reliable basis, on reasonable price conditions and on acceptable economic terms, is one of the major challenges for the future. The overall path leading to a hydrogen oriented energy economy will require the solution of two complex problems, i.e. hydrogen production and hydrogen supply. In this context, it is important to analyse energy demand, emissions and the cost of supplying new energy carriers - including hydrogen as a long-term option - in terms of distribution strategies subject to global, regional as well as local requirements. Hydrogen logistics involves high cost and energy expenditure considering not only the production, conditioning, distribution and storage of hydrogen but also hydrogen management at service stations (for automobile applications) or at refuelling stations (for refuelling cartridges) - see figure. Our conference contribution offers systems analyses for various hydrogen paths up to the end consumer, evaluating the alternative options in terms of energy demand, greenhouse-gas emissions and hydrogen costs at the service stations. The assessment is based on research studies from Forschungszentrum Juelich (2003/04), Linde Gas (2002/04), National Research Council and National Academy of Engineering (2004) and E4Tech (2005). (Author)

  13. Renewable hydrogen production for fossil fuel processing

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, E.; Lee, J.W.; Tevault, C.V. [and others

    1995-06-01

    In the fundamental biological process of photosynthesis, atmospheric carbon dioxide is reduced to carbohydrate using water as the source of electrons with simultaneous evolution of molecular oxygen: H{sub 2}O + CO{sub 2} + light {yields} O{sub 2} + (CH{sub 2}O). It is well established that two light reactions, Photosystems I and II (PSI and PSII) working in series, are required to perform oxygenic photosynthesis. Experimental data supporting the two-light reaction model are based on the quantum requirement for complete photosynthesis, spectroscopy, and direct biochemical analysis. Some algae also have the capability to evolve molecular hydrogen in a reaction energized by the light reactions of photosynthesis. This process, now known as biophotolysis, can use water as the electron donor and lead to simultaneous evolution of molecular hydrogen and oxygen. In green algae, hydrogen evolution requires prior incubation under anaerobic conditions. Atmospheric oxygen inhibits hydrogen evolution and also represses the synthesis of hydrogenase enzyme. CO{sub 2} fixation competes with proton reduction for electrons relased from the photosystems. Interest in biophotolysis arises from both the questions that it raises concerning photosynthesis and its potential practical application as a process for converting solar energy to a non-carbon-based fuel. Prior data supported the requirement for both Photosystem I and Photosystem II in spanning the energy gap necessary for biophotolysis of water to oxygen and hydrogen. In this paper we report the at PSII alone is capable of driving sustained simultaneous photoevolution of molecular hydrogen and oxygen in an anaerobically adapted PSI-deficient strain of Chlamydomonas reinhardtii, mutant B4, and that CO{sub 2} competes as an electron acceptor.

  14. Hydrogen Production by Homogeneous Catalysis: Alcohol Acceptorless Dehydrogenation

    DEFF Research Database (Denmark)

    Nielsen, Martin

    2015-01-01

    in hydrogen production from biomass using homogeneous catalysis. Homogeneous catalysis has the advance of generally performing transformations at much milder conditions than traditional heterogeneous catalysis, and hence it constitutes a promising tool for future applications for a sustainable energy sector...

  15. Hydrogen production by water dissociation from a nuclear reactor

    International Nuclear Information System (INIS)

    This memento presents the production of hydrogen by water decomposition, the energy needed for the electrolysis, the thermochemical cycles for a decomposition at low temperature and the possible nuclear reactors associated. (A.L.B.)

  16. Hydrogen production from fusion reactors coupled with high temperature electrolysis

    International Nuclear Information System (INIS)

    The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and complement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Processes which may be considered for this purpose include electrolysis, thermochemical decomposition or thermochemical-electrochemical hybrid cycles. Preliminary studies at Brookhaven indicate that high temperature electrolysis has the highest potential efficiency for production of hydrogen from fusion. Depending on design electric generation efficiencies of approximately 40 to 60 percent and hydrogen production efficiencies of approximately 50 to 70 percent are projected for fusion reactors using high temperature blankets

  17. Hydrogen production by Clostridium thermolacticum during continuous fermentation of lactose

    Energy Technology Data Exchange (ETDEWEB)

    Collet, C.; Adler, N.; Schwitzguebel, J.P.; Peringer, P. [Swiss Federal Inst. of Technology Lausanne (EPFL) (Switzerland). Lab. for Environmental Biotechnology

    2004-11-01

    In the production of acetate by Clostridium thermolacticum growing on lactose, considerable amounts of hydrogen were generated. Lactose available in large amounts from milk permeate, a waste stream of the dairy industry, appears to be a valuable substrate for cheap production of biohydrogen. In this study, continuous cultivation of C. thermolacticum was carried out in a bioreactor, under anaerobic thermophilic conditions, on minimal medium containing 10 g l{sup -1} lactose. Different dilution rates and pH were tested. C. thermolacticum growing on lactose produced acetate, ethanol and lactate in the liquid phase. For all conditions tested, hydrogen was the main product in the gas phase. Hydrogen specific production higher than 5 mmol H{sub 2} (g cell){sup -1} h{sup -1} was obtained. By operating this fermentation at high-dilution rate and alkaline pH, the hydrogen content in the gas phase was maximized. (author)

  18. Preparation, Characterization, and Enhanced Photo catalytic Hydrogen Evolution Activity of Y2Cu2O5-Based Compounds under Simulated Sunlight Irradiation

    International Nuclear Information System (INIS)

    Y2Cu2O5 photo catalyst was successfully prepared via solid state reaction and further combined with TiO2 by a sol-gel method and a solid phase method, respectively. For comparison, Pt Y2Cu2O5particles were loaded to prepare Pt- via a hydrogen reduction method. All the samples were characterized by thermogravimetry and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), and scanning electron microscopy (SEM) techniques. Photo catalytic H2 evolution activities of the as-obtained samples were evaluated from aqueous oxalic acid solution under simulated sunlight irradiation. The effects of photo catalyst concentration, TiO2 content, and composite method on the H2 evolution activities of the as-obtained photo catalysts were investigated. The results show that, when the concentration of photo catalyst is 0.8 gL-1, the TiO2 Y2Cu2O5 composite photo catalyst prepared by a sol-gel method exhibits the optimized photo catalytic activity, and the H2 production rate is 4.35 m mol with 30 wt.% content of TiO2

  19. Pyrolysis of de-oiled seed cake of Jatropha Curcas and catalytic steam reforming of pyrolytic bio-oil to hydrogen.

    Science.gov (United States)

    Renny, Andrew; Santhosh, Viswanathan; Somkuwar, Nitin; Gokak, D T; Sharma, Pankaj; Bhargava, Sanjay

    2016-11-01

    The aim of this work was to study the pyrolysis of de-oiled seed cake of Jatropha Curcas and catalytic steam reforming of pyrolytic bio-oil to hydrogen. As per literature, presence of heavy nitrogenous and oxygenated compounds leads to catalyst deactivation. Here, an attempt has been made to tune pyrolytic reactions to optimize the N and O content of the pyrolytic bio-oil. Bio-oil conversion and hydrogen yield decreased as reaction progressed, which attributes to temporary loss of catalytic activity by blockage of catalyst pores by carbon deposition. Further, retention of steam reforming activity after repetitive steam activation suggests long-term catalyst usage. PMID:27566523

  20. Pyrolysis of de-oiled seed cake of Jatropha Curcas and catalytic steam reforming of pyrolytic bio-oil to hydrogen.

    Science.gov (United States)

    Renny, Andrew; Santhosh, Viswanathan; Somkuwar, Nitin; Gokak, D T; Sharma, Pankaj; Bhargava, Sanjay

    2016-11-01

    The aim of this work was to study the pyrolysis of de-oiled seed cake of Jatropha Curcas and catalytic steam reforming of pyrolytic bio-oil to hydrogen. As per literature, presence of heavy nitrogenous and oxygenated compounds leads to catalyst deactivation. Here, an attempt has been made to tune pyrolytic reactions to optimize the N and O content of the pyrolytic bio-oil. Bio-oil conversion and hydrogen yield decreased as reaction progressed, which attributes to temporary loss of catalytic activity by blockage of catalyst pores by carbon deposition. Further, retention of steam reforming activity after repetitive steam activation suggests long-term catalyst usage.

  1. Chemistry and catalysis of coal liquefaction: catalytic and thermal upgrading of coal liquid and hydrogenation of CO to produce fuels. Quarterly progress report, January-March 1980

    Energy Technology Data Exchange (ETDEWEB)

    Wiser, W.H.

    1980-08-01

    Analysis of a group of coal liquids produced by catalytic hydrogenation of Utah coals with ZnCl/sub 2/ catalyst was begun. Carbon-13 nuclear magnetic resonance and liquid chromatography techniques will be used to correlate chemical properties with hydrogenation reactivity. Equipment previously used for downflow measurements of heat and momentum transfer in a gas-coal suspension was modified for upflow measurements. The catalytic hydrodeoxygenation of methyl benzoate has been studied to elucidate the reactions of ester during upgrading of coal-derived liquids. The kinetics of hydrogenation of phenanthrene have also been determined. The catalytic cracking mechanism of octahydroanthracene is reported in detail. Studies of the hydrodesulfurization of thiophene indicate that some thiophene is strongly adsorbed as a hydrogen-deficient polymer on cobalt-molybdate catalyst. Part of the polymer can be desorbed as thiophene by hydrogenation. Poisoning of the catalyst inhibits the hydrosulfurization activity to a greater degree than the hydrogenation activity. Iron-manganese catalysts for carbon monoxide hydrogenation is studied to determine the role of iron carbide formation on selectivity. Pure iron catalyst forms a Hagg iron carbide phase under reaction conditions.

  2. Fermentative hydrogen production from microalgal biomass and agricultural wastes

    OpenAIRE

    Moura, Patrícia

    2013-01-01

    Renewable, sustainable and carbon-neutral energy production is needed to deal with the challenges of the currently growing energy demand and deleterious climate changes. Hydrogen (H2) is presently seen as an ideal future energy carrier with technical, socio-economic and environmental benefits. H2 can be produced through biological conversion by photosynthesis, photo-heterotrophic and dark fermentation. The interest in biological hydrogen (bioH2) production has recently increased, as the tradi...

  3. A novel rotary reactor configuration for simultaneous production of hydrogen and carbon nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Pinilla, J.L.; Utrilla, R.; Lazaro, M.J.; Suelves, I.; Moliner, R. [Instituto de Carboquimica CSIC, Miguel Luesma 4, 50018 Zaragoza (Spain); Palacios, J.M. [Instituto de Catalisis y Petroleoquimica CSIC, Cantoblanco, Marie Curie 2, 28049-Madrid (Spain)

    2009-10-15

    A novel reactor configuration, a rotary bed reactor (RBR), was used to study at large scale production the Catalytic Decomposition of Methane (CDM) into hydrogen and carbon nanofibers using a nickel-copper catalyst. The results were compared to those obtained in a fluidized bed reactor (FBR) under the same operating conditions. Tests carried out in the RBR provided higher hydrogen yields and more sustainable catalyst performance in comparison to the FBR. Additionally, the effect of the rotation speed and reaction temperature on the performance in the RBR of the nickel-copper catalyst was studied. The textural and structural properties of the carbon nanofibers produced were also studied by means of N{sub 2} adsorption, SEM and XRD, and compared to those obtained in the FBR set-up under the same operating conditions. (author)

  4. A trimodal porous carbon as an effective catalyst for hydrogen production by methane decomposition.

    Science.gov (United States)

    Shen, Yi; Lua, Aik Chong

    2016-01-15

    A new type of porous carbon with an interconnected trimodal pore system is synthesized by a nanocasting method using nanoparticulated bimodal micro-mesoporous silica particles as the template. The synthesized template and carbon material are characterized using transmission electron microscopy (TEM), field emission electron scanning microscopy (FESEM) and nitrogen adsorption-desorption test. The synthesized carbon material has an extremely high surface area, a large pore volume and an interconnected pore structure, which could provide abundant active sites and space for chemical reactions and minimize the diffusion resistance of the reactants. The resulting carbon is used as the catalyst for hydrogen production by the thermal decomposition of methane. The catalytic results show that the as-synthesized carbon in this study produces much higher methane conversion and hydrogen yield than the commercial carbon materials. PMID:26433477

  5. The Activity of Ni-Based Catalysts on Steam Reforming of Glycerol for Hydrogen Production

    Directory of Open Access Journals (Sweden)

    ALI SALEM EBSHISH

    2011-09-01

    Full Text Available Glycerol, the readily available bio renewable material, is effectively utilized for hydrogen production by a steam reforming reaction. The experiments were carried out in a continuous flow fixed-bed reactor over Nickel supported alumina catalysts under atmospheric pressure at 600°C and three hours reaction time. 5%wt Ni was loaded over γ-Al2O3 and effect of promoter metals such as Fe and Co over Ni/γ-Al2O3 catalytic systems were evaluated. The catalysts were characterized by BET surface area, XRD and SEM techniques. The activity results showed that the addition of Co enhanced the catalyst performance. The catalysts exhibited a good activity and selectivity to hydrogen.

  6. PHOTOBIOREACTOR FOR HYDROGEN PRODUCTION FROM CATTLE MANURE

    Science.gov (United States)

    Hydrogen has been identified as an energy-efficient and pollution-free energy carrier that has the potential to replace the existing nonrenewable fossil fuels. The student team at the New Mexico State University will design a prototype of an anaerobic reactor for biohydrogen ...

  7. Catalytic Hydrogenation of Methanol-Containing Eflfuent from Epoxidation of Propylene

    Institute of Scientific and Technical Information of China (English)

    Cheng Ke

    2015-01-01

    This paper describes the hydrogenation of impurities in the methanol-containing eflfuent from the propylene epoxidation process with hydrogen peroxide. The effects of reaction temperature, pressure, weight hourly space velocity (WHSV) and H2/methanol ratio on the concentration of various impurities in methanol solvent were investigated. It was found out that the aldehyde, hydrogen peroxide and nitro compounds in the methanol solvent could be completely hydroge-nated over the Ni catalyst under proper reaction conditions. 90%of acetone and up to 50%of acetals (ketals) existing in the methanol solvent could be hydrogenated. No signiifcant change was observed for the rest of the impurities that were present in the methanol solvent (i. e., 1-methoxy-2-propanol, 2-methoxy-1-propanol and 1,2-propanediol). The H2O2 decomposition reaction was enhanced using Ni catalyst, through the formation of NioOH, but no oxygen was found in the off-gas of hy-drogenation reaction since NioH could react on NioOH formed via dissociative adsorption of hydrogen peroxide, or on NioO formed via adsorption of oxygen.

  8. Unsteady catalytic processes and sorption-catalytic technologies

    International Nuclear Information System (INIS)

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

  9. Unsteady catalytic processes and sorption-catalytic technologies

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-31

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

  10. In vitro hydrogen production by glucose dehydrogenase and hydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Woodward, J. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    A new in vitro enzymatic pathway for the generation of molecular hydrogen from glucose has been demonstrated. The reaction is based upon the oxidation of glucose by Thermoplasma acidophilum glucose dehydrogenase with the concomitant oxidation of NADPH by Pyrococcus furiosus hydrogenase. Stoichiometric yields of hydrogen were produced from glucose with continuous cofactor recycle. This simple system may provide a method for the biological production of hydrogen from renewable sources. In addition, the other product of this reaction, gluconic acid, is a high-value commodity chemical.

  11. Preparation and Characterizations of In0.1SnxZn0.85-2xS for Hydrogen Production Under Visible Light Irradiation

    International Nuclear Information System (INIS)

    A series of In0.1SnxZn0.85-2xS solid solutions was synthesized by hydrothermal method and employed as photo catalyst for photo catalytic hydrogen evolution under visible light irradiation. From the characterizations, it was confirmed that In0.1SnxZn0.85-2xS solid solution can be obtained and they have nano-sized particles. The highest photo catalytic activity was observed on In0.1Sn0.03Zn0.79S photo catalyst, with average rate of hydrogen production 3.05 mmol/h. (author)

  12. Enrichment and hydrogen production by marine anaerobic hydrogen-producing microflora

    Institute of Scientific and Technical Information of China (English)

    CAI JinLing; WANG GuangCe; LI YanChuan; ZHU DaLing; PAN GuangHua

    2009-01-01

    Acid,alkali,heat-shock,KNO3 and control pretreatment methods applied to anaerobic sludge were evaluated for their ability to selectively enrich the marine hydrogen-producing mixed microflora.Seawater culture medium was used as the substrate.The hydrogen yield of pretreated microflora was higher than that of the un-pretreated control (P<0.05).Among the pretreatment methods studied,heat-shock pretreatment yielded the greatest hydrogen production,which was 14.6 times that of the control.When the effect of initial pH on hydrogen production of heat-shock pretreated samples was studied,hydrogen was produced over the entire pH range (pH 4-10).The hydrogen yield peaked at initial pH 8 (79 mL/g sucrose) and then steadily decreased as the initial pH increased.Sucrose consumption was high at neutral initial pH.During the process of hydrogen production,pH decreased gradually,which indicated that the acquired microflora consisted of acidogenic bacteria.

  13. Methane Pyrolysis for Hydrogen & Carbon Nanotube Recovery from Sabatier Products Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a microgravity and hypogravity compatible catalytic methane pyrolysis reactor is proposed to recover hydrogen which is lost as methane in the...

  14. Biological hydrogen production measured in batch anaerobic respirometers.

    Science.gov (United States)

    Logan, Bruce E; Oh, Sang-Eun; Kim, In S; Van Ginkel, Steven

    2002-06-01

    The biological production of hydrogen from the fermentation of different substrates was examined in batch tests using heat-shocked mixed cultures with two techniques: an intermittent pressure release method (Owen method) and a continuous gas release method using a bubble measurement device (respirometric method). Under otherwise identical conditions, the respirometric method resulted in the production of 43% more hydrogen gas from glucose than the Owen method. The lower conversion of glucose to hydrogen using the Owen protocol may have been produced by repression of hydrogenase activity from high partial pressures in the gastight bottles, but this could not be proven using a thermodynamic/rate inhibition analysis. In the respirometric method, total pressure in the headspace never exceeded ambient pressure, and hydrogen typically composed as much as 62% of the headspace gas. High conversion efficiencies were consistently obtained with heat-shocked soils taken at different times and those stored for up to a month. Hydrogen gas composition was consistently in the range of 60-64% for glucose-grown cultures during logarithmic growth but declined in stationary cultures. Overall, hydrogen conversion efficiencies for glucose cultures were 23% based on the assumption of a maximum of 4 mol of hydrogen/ mol of glucose. Hydrogen conversion efficiencies were similar for sucrose (23%) and somewhat lower for molasses (15%) but were much lower for lactate (0.50%) and cellulose (0.075%).

  15. Study on biomass catalytic pyrolysis for production of bio-gasoline by on-line FTIR

    Institute of Scientific and Technical Information of China (English)

    Chang Bo Lu; Jian Zhong Yao; Wei Gang Lin; Wen Li Song

    2007-01-01

    The pyrolysis of biomass is a promising way for production of bio-gasoline if the stability and quality problems of the bio-crudeoil can be solved by catalytic cracking and reforming. In this paper, an on-line infrared spectrum was used to study the characteristics of catalytic pyrolysis with the following preliminary results. The removal of C=O of organic acid is more difficult than that of aldehydes and ketones. HUSY/γ-Al2O3 and REY/γ-Al2O3 catalysts exhibited better deoxygenating activities while HZSM-5/γ-Al2O3 catalyst exhibited preferred selectivities for production of iso-alkanes and aromatics. Finally, possible mechanisms of biomass catalytic pyrolysis are discussed as well.

  16. Identification of intrinsic catalytic activity for electrochemical reduction of water molecules to generate hydrogen

    KAUST Repository

    Shinagawa, Tatsuya

    2015-01-01

    Insufficient hydronium ion activities at near-neutral pH and under unbuffered conditions induce diffusion-limited currents for hydrogen evolution, followed by a reaction with water molecules to generate hydrogen at elevated potentials. The observed constant current behaviors at near neutral pH reflect the intrinsic electrocatalytic reactivity of the metal electrodes for water reduction. This journal is © the Owner Societies.

  17. Bio-hydrogen Production Potential from Market Waste

    Directory of Open Access Journals (Sweden)

    Lanna Jaitalee

    2010-07-01

    Full Text Available This research studied bio-hydrogen production from vegetable waste from a fresh market in order to recover energy. A series of batch experiments were conducted to investigate the effects of initial volatile solids concentration on the bio-hydrogen production process. Lab bench scale anaerobic continuous stirred-tank reactors (CSTR were used to study the effect of substrate and sludge inoculation on hydrogen production. Three different concentrations of initial total volatile solids (TVS of organic waste were varied from 2%, 3% and 5% respectively. The pH was controlled at 5.5 for all batches in the experiment. The results showed that bio-hydrogen production depended on feed-substrate concentration. At initial TVS content of 3%, the highest hydrogen production was achieved at a level of 0.59 L-H2/L at pH 5.5. The maximum hydrogen yield was 15.3 ml H2/g TVS or 8.5 ml H2/g COD. The composition of H2 in the biogas ranged from 28.1-30.9% and no CH4 was detected in all batch tests.

  18. Hydrocarbon Liquid Production from Biomass via Hot-Vapor-Filtered Fast Pyrolysis and Catalytic Hydroprocessing of the Bio-oil

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Douglas C.; Wang, Huamin; French, Richard; Deutch, Steve; Iisa, Kristiina

    2014-08-14

    Hot-vapor filtered bio-oils were produced from two different biomass feedstocks, oak and switchgrass, and the oils were evaluated in hydroprocessing tests for production of liquid hydrocarbon products. Hot-vapor filtering reduced bio-oil yields and increased gas yields. The yields of fuel carbon as bio-oil were reduced by ten percentage points by hot-vapor filtering for both feedstocks. The unfiltered bio-oils were evaluated alongside the filtered bio-oils using a fixed bed catalytic hydrotreating test. These tests showed good processing results using a two-stage catalytic hydroprocessing strategy. Equal-sized catalyst beds, a sulfided Ru on carbon catalyst bed operated at 220°C and a sulfided CoMo on alumina catalyst bed operated at 400°C were used with the entire reactor at 100 atm operating pressure. The products from the four tests were similar. The light oil phase product was fully hydrotreated so that nitrogen and sulfur were below the level of detection, while the residual oxygen ranged from 0.3 to 2.0%. The density of the products varied from 0.80 g/ml up to 0.86 g/ml over the period of the test with a correlated change of the hydrogen to carbon atomic ratio from 1.79 down to 1.57, suggesting some loss of catalyst activity through the test. These tests provided the data needed to assess the suite of liquid fuel products from the process and the activity of the catalyst in relationship to the existing catalyst lifetime barrier for the technology.

  19. H2CAP - Hydrogen assisted catalytic biomass pyrolysis for green fuels

    DEFF Research Database (Denmark)

    Arndal, Trine Marie Hartmann; Høj, Martin; Jensen, Peter Arendt;

    2014-01-01

    Pyrolysis of biomass produces a high yield of condensable oil at moderate temperature and low pressure.This bio-oil has adverse properties such as high oxygen and water contents, high acidity and immiscibility with fossil hydrocarbons. Catalytic hydrodeoxygenation (HDO) is a promising technology...... that can be used to upgrade the crude bio-oil to fuel-grade oil. The development of the HDO process is challenged by rapid catalyst deactivation, instability of the pyrolysis oil, poorly investigated reaction conditions and a high complexity and variability of the input oil composition. However, continuous...... catalytic hydropyrolysis coupled with downstream HDO of the pyrolysis vapors before condensation shows promise (Figure 1). A bench scale experimental setup will be constructed for the continuous conversion of solid biomass (100g /h) to low oxygen, fuel-grade bio-oil. The aim is to provide a proof...

  20. Hydrogen Production from Semiconductor-based Photocatalysis via Water Splitting

    Directory of Open Access Journals (Sweden)

    Jeffrey C. S. Wu

    2012-10-01

    Full Text Available Hydrogen is the ideal fuel for the future because it is clean, energy efficient, and abundant in nature. While various technologies can be used to generate hydrogen, only some of them can be considered environmentally friendly. Recently, solar hydrogen generated via photocatalytic water splitting has attracted tremendous attention and has been extensively studied because of its great potential for low-cost and clean hydrogen production. This paper gives a comprehensive review of the development of photocatalytic water splitting for generating hydrogen, particularly under visible-light irradiation. The topics covered include an introduction of hydrogen production technologies, a review of photocatalytic water splitting over titania and non-titania based photocatalysts, a discussion of the types of photocatalytic water-splitting approaches, and a conclusion for the current challenges and future prospects of photocatalytic water splitting. Based on the literatures reported here, the development of highly stable visible–light-active photocatalytic materials, and the design of efficient, low-cost photoreactor systems are the key for the advancement of solar-hydrogen production via photocatalytic water splitting in the future.

  1. Non-catalytic transfer hydrogenation in supercritical CO2 for coal liquefaction

    Science.gov (United States)

    Elhussien, Hussien

    This thesis presents the results of the investigation on developing and evaluating a low temperature (products of coal dissolution were non-polar and polar while the supercritical CO2, which enhanced the rates of hydrogenation and dissolution of the non-polar molecules and removal from the reaction site, was non-polar. The polar modifier (PM) for CO2 was added to the freed to aid in the dissolution and removal of the polar components. The addition of a phase transfer agent (PTA) allowed a seamless transport of the ions and by-product between the aqueous and organic phases. DDAB, used as the PTA, is an effective phase transfer catalyst and showed enhancement to the coal dissolution process. COAL + DH- +H 2O → COAL.H2 + DHO-- This process has a great feature due to the fact that the chemicals were obtained without requir-ing to first convert coal to CO and H2 units as in indirect coal liquefaction. The experiments were conducted in a unique reactor set up that can be connected through two lines. one line to feed the reactor with supercritical CO 2 and the other connected to gas chromatograph. The use of the supercritical CO2 enhanced the solvent option due to the chemical extraction, in addition to the low environmental impact and energy cost. In this thesis the experiment were conducted at five different temperatures from atmos-pheric to 140°C, 3000 - 6000 psi with five component of feed mixture, namely water, HTA, PTA, coal, and PM in semi batch vessels reactor system with a volume of 100 mL. The results show that the chemicals were obtained without requiring to first convert coal to CO and H2 units as in indirect coal liquefaction. The results show that the conversion was found to be 91.8% at opti-mum feed mixtures values of 3, 1.0 and 5.4 for water: PM, HTA: coal, water: coal respectively. With the oil price increase and growing in energy demand, the coal liquefaction remain affordable and available energy alternative.

  2. A thermal hydraulic analysis model for catalytic hydrogen recombiners in the containment vessel of a BWR

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Tadashi; Fujimoto, Kiyoshi [Power and Industrial Systems Rand D Division, Hitachi LTD., HItachi Ibaraki (Japan); Yamanari, Shouzou; Yoshinari, Yasuo

    1999-07-01

    Passive catalytic recombiners have been developed as a safety system to lower flammable gases concentrations in a nuclear power plant accident. Passive catalytic recombiners are of very simple construction and free of active components, which hold the promise of better plant economy, maintainability and reliability. In evaluation of the performance of the recombiners, the clarification of the diffusion and mixing behaviors of flammable gases in the primary containment vessel (PCV) is desirable. The diffusion/mixing behaviors of flammable gases are affected by natural circulation flow induced by the exothermic reaction of the recombiner, forced flow due to the PCV spray and interference by the obstacles in the PCV (such as pipings and components). As an analytical tool to deal with thermal hydraulic behaviors for passive catalytic recombiners, the authors have studied applicability of a three-dimensional analysis code. From the viewpoint of analytical capabilities, the authors selected the STAR-CD code. This paper describes the applicability of the code, including verification analysis and preliminary evaluation for a BWR plant. (author)

  3. Room Temperature Reactivity Of Silicon Nanocrystals With Solvents: The Case Of Ketone And Hydrogen Production From Secondary Alcohols: Catalysis?

    KAUST Repository

    El-Demellawi, Jehad

    2015-05-29

    Although silicon nanoparticles dispersed in liquids are used in various applications ranging from bio-labeling to hydrogen production, their reactivities with their solvents and their catalytic properties re-main still unexplored. Here, we discovered that, because of their surface structures and mechanical strain, silicon nanoparticles react strongly with their solvents and may act as catalysts for the dehydrogenation, at room temperature, of secondary alcohols (e.g. isopropanol) to ketones and hydrogen. This catalytic reaction was followed by gas chromatography, pH measurements, mass spectroscopy and solidstate NMR. This discovery provides new understanding of the role played by silicon nanoparticles, and nanosilicon in general, in their stability in solvents in general as well as being candidates in catalysis.

  4. Hydrogen production from wastewater sludge using a Clostridium strain.

    Science.gov (United States)

    Wang, C C; Chang, C W; Chu, C P; Lee, D J; Chang, B V; Liao, C S

    2003-09-01

    Limited data in literature revealed a relatively low hydrogen yield from wastewater sludge, ca. 0.16 mg/g-dried solids, using anaerobic fermentation. We demonstrated in this work a much higher hydrogen yield, around 1.1 mg-H2/g-dried solids using a clostridium strain isolated from the sludge sample. The formed hydrogen would be consumed after passing the peak value at around 30-36 h of fermentation. We examined the effects of employing five different pre-treatments on substrate sludge, but noted no appreciable enhancement in hydrogen yield as commonly expected for methane production. Since a vast amount of organic matters had been released to water after hydrogen fermentation, we externally dosed methanogenic bacteria to the fermented liquor to produce methane. The fermented liquor could produce more methane than the non-fermented sample, indicating that the dosed methanogenic bacteria readily utilized the organic matters derived from the fermentation test.

  5. Biological Hydrogen Production Using Chloroform-treated Methanogenic Granules

    Science.gov (United States)

    Hu, Bo; Chen, Shulin

    In fermentative hydrogen production, the low-hydrogen-producing bacteria retention rate limits the suspended growth reactor productivity because of the long hydraulic retention time (HRT) required to maintain adequate bacteria population. Traditional bacteria immobilization methods such as calcium alginate entrapment have many application limitations in hydrogen fermentation, including limited duration time, bacteria leakage, cost, and so on. The use of chloroform-treated anaerobic granular sludge as immobilized hydrogen-producing bacteria in an immobilized hydrogen culture may be able to overcome the limitations of traditional immobilization methods. This paper reports the findings on the performance of fed-batch cultures and continuous cultures inoculated with chloroform-treated granules. The chloroform-treated granules were able to be reused over four fed-batch cultures, with pH adjustment. The upflow reactor packed with chloroform-treated granules was studied, and the HRT of the upflow reactor was found to be as low as 4 h without any decrease in hydrogen production yield. Initial pH and glucose concentration of the culture medium significantly influenced the performance of the reactor. The optimum initial pH of the culture medium was neutral, and the optimum glucose concentration of the culture medium was below 20 g chemical oxygen demand/L at HRT 4 h. This study also investigated the possibility of integrating immobilized hydrogen fermentation using chloroform-treated granules with immobilized methane production using untreated granular sludge. The results showed that the integrated batch cultures produced 1.01 mol hydrogen and 2 mol methane per mol glucose. Treating the methanogenic granules with chloroform and then using the treated granules as immobilized hydrogen-producing sludge demonstrated advantages over other immobilization methods because the treated granules provide hydrogen-producing bacteria with a protective niche, a long duration of an active

  6. Size Control of Iron Oxide Nanoparticles Using Reverse Microemulsion Method: Morphology, Reduction, and Catalytic Activity in CO Hydrogenation

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Housaindokht

    2013-01-01

    Full Text Available Iron oxide nanoparticles were prepared by microemulsion method and evaluated in Fischer-Tropsch synthesis. The precipitation process was performed in a single-phase microemulsion operating region. Different HLB values of surfactant were prepared by mixing of sodium dodecyl sulfate (SDS and Triton X-100. Transmission electron microscopy (TEM, surface area, pore volume, average pore diameter, pore size distribution, and XRD patterns were used to analyze size distribution, shape, and structure of precipitated hematite nanoparticles. Furthermore, temperature programmed reduction (TPR and catalytic activity in CO hydrogenation were implemented to assess the performance of the samples. It was found that methane and CO2 selectivity and also the syngas conversion increased as the HLB value of surfactant decreased. In addition, the selectivity to heavy hydrocarbons and chain growth probability (α decreased by decreasing the catalyst crystal size.

  7. Synthesis and Catalytic Performance of Ni/SiO2 for Hydrogenation of 2-Methylfuran to 2-Methyltetrahydrofuran

    Directory of Open Access Journals (Sweden)

    Fu Ding

    2015-01-01

    Full Text Available A series of Ni/SiO2 catalysts with different Ni content were prepared by sol-gel method for application in the synthesis of 2-methyltetrahydrofuran (2-MTHF by hydrogenation of 2-methylfuran (2-MF. The catalyst structure was investigated by X-ray diffraction (XRD, transmission electron microscopy (TEM, X-ray photoelectron spectroscopy (XPS, and temperature programmed reduction (TPR. It is found that structures and catalytic performance of the catalysts were highly affected by the Ni content. The catalyst with a 25% Ni content had an appropriate size of the Ni species and larger BET surface area and produced a higher 2-MF conversion with enhanced selectivity in 2-MTHF.

  8. Preparation and Characterization of A New Dinuclear Ruthenium Complex with BDPX Ligand and Its Catalytic Hydrogenation Reactions for Cinnamaldehyde

    Institute of Scientific and Technical Information of China (English)

    TANG,Yuan-You(唐元友); LI,Rui-Xiang(李瑞祥); LI,Xian-Jun(李贤均); WONG,Ning-Bew(黄宁表); TIN,Kim-Chung(田金忠); ZHANG,Zhe-Ying(张哲英); MAK,Thomas C.W.(麦松威)

    2004-01-01

    A new anionic dinuclear ruthenium complex bearing 1,2-bis(diphenylphosphinomethyl)benzene (BDPX)[NH2Et2][{RuCl (BDPX)}2(μ-Cl)3] (1) was synthesized and its structure was determined by an X-ray crystallographic analysis. This result indicated that complex 1 consisted of an anion dinuclear BDPX-Ru and a cationic diethylammonium. The crystal belonged to monoclinic system, C2/c space group with a=3.3552(7) nm, b= 1.8448(4)nm, c=2.4265(5) nm, β= 101.89(3)° and Z=8. The catalytic hydrogenation activities and selectivities of complex 1 for cinnamaldehyde were investigated.

  9. Effects of hydrophobic carrier and packing on the mass transfer capabilities in hydrogen-water liquid phase catalytic exchange bed

    International Nuclear Information System (INIS)

    Hydrogen-water liquid phase catalytic exchange bed was packed with 'sandwich' layers of the catalyst and the packing, and the effects of catalyst carrier, inert packing and their filled ratio on the overall mass transfer coefficient (Kya) were investigated experimentally. The results show that C-PTFE is suitable for hydrophobic catalyst. Kya of the bed with catalyst-stainless steel mini-spiral packing is better than that with stainless steel θ-packing, and the active Al2O3 is not suitable for the exchange bed. Moreover, if the stainless steel mini-spiral packing is etched in aqua regia, the operating flexibility and overall mass transfer capability of exchange bed are improved notably. The preferable packing ratio (catalyst/packing) is 1:4. (authors)

  10. Using short pulses to enhance the production rate of vibrationally excited hydrogen molecules in hydrogen discharge

    Institute of Scientific and Technical Information of China (English)

    Sun Ji-Zhong; Li Xian-Tao; Bai Jing; Wang De-Zhen

    2012-01-01

    Hydrogen discharges driven by the combined radio-frequency(rf)/short pulse sources are investigated using the particle-in-cell method.The simulation results show that the discharge driven additionally by the short pulse can enhance the electron density and modulate the electron energy to provide a better condition for negative hydrogen ion production than the discharge driven by the rf-only source.

  11. Production of bio-fuels from cottonseed cake by catalytic pyrolysis under steam atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Puetuen, Ersan [Department of Material Science and Engineering, Anadolu University, Iki Eyluel Campus, 26555 Eskisehir (Turkey); Uzun, Basak Burcu; Puetuen, Ayse Eren [Department of Chemical Engineering, Anadolu University, Iki Eyluel Campus, 26555 Eskisehir (Turkey)

    2006-06-15

    The purpose of this study is to evaluate the amounts of catalytic pyrolysis products of cottonseed cake in steam atmosphere and investigate the effects of both zeolite and steam on pyrolysis yields. The effect of steam was investigated by co-feeding steam at various velocities (0.6:1.3:2.7cms{sup -1}) in the presence of zeolite (20wt% of feed). Liquid pyrolysis products obtained at the most appropriate conditions were fractionated by column chromatography. Elemental analysis and FT-IR were applied on both of these liquid products and their sub-fractions. The H/C ratios obtained from elemental analysis were compared with the petroleum products. The aliphatic sub-fractions of the oils were then analysed by capillary column gas chromatography. Further structural analysis of pyrolysis oil was conducted using {sup 1}H-NMR spectroscopy. The characterization has shown that the bio-oil obtained from catalytic and steam pyrolysis of cottonseed cake was more beneficial than those obtained from non-catalytic and catalytic works under static and nitrogen atmospheres. (author)

  12. Investigation of the By-products Formed during the Catalytic Synthesis of 4,4'-Methylenedimethyldiphenylcarbamate

    Institute of Scientific and Technical Information of China (English)

    QIU, Ze-Gang; WANG, Jun-Wei; KANG, Mao-Qing; LI, Qi-Feng; DU, Hui; WANG, Xin-Kui

    2007-01-01

    The structures of the by-products formed during the catalytic synthesis of 4,4'-methylenedimethyldiphenylcarbamate (MDC) by the reaction of 4,4'-methylenedianiline (MDA) with dimethyl carbonate (DMC) were identified and then the mechanisms of their formation were proposed.

  13. Technoeconomic analysis of renewable hydrogen production, storage, and detection systems

    Energy Technology Data Exchange (ETDEWEB)

    Mann, M.K.; Spath, P.L.; Kadam, K. [National Renewable Energy Lab., Golden, CO (United States)

    1996-10-01

    Technical and economic feasibility studies of different degrees of completeness and detail have been performed on several projects being funded by the Department of Energy`s Hydrogen Program. Work this year focused on projects at the National Renewable Energy Laboratory, although analyses of projects at other institutions are underway or planned. Highly detailed analyses were completed on a fiber optic hydrogen leak detector and a process to produce hydrogen from biomass via pyrolysis followed by steam reforming of the pyrolysis oil. Less detailed economic assessments of solar and biologically-based hydrogen production processes have been performed and focused on the steps that need to be taken to improve the competitive position of these technologies. Sensitivity analyses were conducted on all analyses to reveal the degree to which the cost results are affected by market changes and technological advances. For hydrogen storage by carbon nanotubes, a survey of the competing storage technologies was made in order to set a baseline for cost goals. A determination of the likelihood of commercialization was made for nearly all systems examined. Hydrogen from biomass via pyrolysis and steam reforming was found to have significant economic potential if a coproduct option could be co-commercialized. Photoelectrochemical hydrogen production may have economic potential, but only if low-cost cells can be modified to split water and to avoid surface oxidation. The use of bacteria to convert the carbon monoxide in biomass syngas to hydrogen was found to be slightly more expensive than the high end of currently commercial hydrogen, although there are significant opportunities to reduce costs. Finally, the cost of installing a fiber-optic chemochromic hydrogen detection system in passenger vehicles was found to be very low and competitive with alternative sensor systems.

  14. Modeling and Simulation of the Hydrogenation of α-Methylstyrene on Catalytically Active Metal Foams as Tubular Reactor Packing

    Directory of Open Access Journals (Sweden)

    Farzad Lali

    2016-01-01

    Full Text Available This work presents a one-dimensional reactor model for a tubular reactor packed with a catalytically active foam packing with a pore density of 30 PPI in cocurrent upward flow in the example of hydrogenation reaction of α-methylstyrene to cumene. This model includes material, enthalpy, and momentum balances as well as continuity equations. The model was solved within the parameter space applied for experimental studies under assumption of a bubbly flow. The method of orthogonal collocation on finite elements was applied. For isothermal and polytropic processes and steady state conditions, axial profiles for concentration, temperature, fluid velocities, pressure, and liquid holdup were computed and the conversions for various gas and liquid flow rates were validated with experimental results. The obtained results were also compared in terms of space time yield and catalytic activity with experimental results and stirred tank and also with random packed bed reactor. The comparison shows that the application of solid foams as reactor packing is advantageous compared to the monolithic honeycombs and random packed beds.

  15. Improvement of hydrogen isotope exchange reactions on Li4SiO4 ceramic pebble by catalytic metals

    Institute of Scientific and Technical Information of China (English)

    Cheng Jian Xiao; Chun Mei Kang; Xiao Jun Chen; Xiao Ling Gao; Yang Ming Luo; Sheng Hu; Xiao Lin Wang

    2012-01-01

    Li4SiO4 ceramic pebble is considered as a candidate tritium breeding material of Chinese Helium Cooled Solid Breeder Test Blanket Module (CH HCSB TBM) for the International Thermonuclear Experimental Reactor (ITER).In this paper,Li4SiO4 ceramic pebbles deposited with catalytic metals,including Pt,Pd,Ru and Ir,were prepared by wet impregnation method.The metal particles on Li4SiO4 pebble exhibit a good promotion of hydrogen isotope exchange reactions in H2-DzO gas system,with conversion equilibrium temperature reduction of 200-300 ℃.The out-of-pile tritium release experiments were performed using 1.0 wt% Pt/Li4SiO4 and Li4SiO4 pebbles irradiated in a thermal neutron reactor.The thermal desorption spectroscopy shows that Pt was effective to increase the tritium release rate at lower temperatures,and the ratio of tritium molecule (HT) to tritiated water (HTO) of 1.0 wt% Pt/Li4SiO4 was much more than that of Li4SiO4,which released mainly as HTO.Thus,catalytic metals deposited on Li4SiO4 pebble may help to accelerate the recovery of bred tritium particularly in low temperature region,and increase the tritium molecule form released from the tritium breeding materials.

  16. Selective Catalytic Hydrogenations of Nitriles, Ketones, and Aldehydes by Well-Defined Manganese Pincer Complexes.

    Science.gov (United States)

    Elangovan, Saravanakumar; Topf, Christoph; Fischer, Steffen; Jiao, Haijun; Spannenberg, Anke; Baumann, Wolfgang; Ludwig, Ralf; Junge, Kathrin; Beller, Matthias

    2016-07-20

    Hydrogenations constitute fundamental processes in organic chemistry and allow for atom-efficient and clean functional group transformations. In fact, the selective reduction of nitriles, ketones, and aldehydes with molecular hydrogen permits access to a green synthesis of valuable amines and alcohols. Despite more than a century of developments in homogeneous and heterogeneous catalysis, efforts toward the creation of new useful and broadly applicable catalyst systems are ongoing. Recently, Earth-abundant metals have attracted significant interest in this area. In the present study, we describe for the first time specific molecular-defined manganese complexes that allow for the hydrogenation of various polar functional groups. Under optimal conditions, we achieve good functional group tolerance, and industrially important substrates, e.g., for the flavor and fragrance industry, are selectively reduced. PMID:27219853

  17. Esterification of glycerol from biodiesel production to glycerol carbonate in non-catalytic supercritical dimethyl carbonate

    OpenAIRE

    Ilham, Zul; Saka, Shiro

    2016-01-01

    Conversion of glycerol from biodiesel production to glycerol carbonate was studied by esterification with dimethyl carbonate in a non-catalytic supercritical condition. It was found that in a non-catalytic supercritical condition, glycerol at higher purity gave higher yield of glycerol carbonate at 98 wt% after reaction at 300 °C/20–40 MPa/15 min. The yield of glycerol carbonate was observed to increase with molar ratio, temperature, pressure and time until a certain equilibrium limit. The ex...

  18. Facile synthesis of polypyrrole functionalized nickel foam with catalytic activity comparable to Pt for the poly-generation of hydrogen and electricity

    Science.gov (United States)

    Tang, Tiantian; Li, Kan; Shen, Zhemin; Sun, Tonghua; Wang, Yalin; Jia, Jinping

    2016-01-01

    Polypyrrole functionalized nickel foam is facilely prepared through the potentiostatic electrodeposition. The PPy-functionalized Ni foam functions as a hydrogen-evolution cathode in a rotating disk photocatalytic fuel cell, in which hydrogen energy and electric power are generated by consuming organic wastes. The PPy-functionalized Ni foam cathode exhibits stable catalytic activities after thirteen continuous runs. Compared with net or plate structure, the Ni foam with a unique three-dimensional reticulate structure is conducive to the electrodeposition of PPy. Compared with Pt-group electrode, PPy-coated Ni foam shows a satisfactory catalytic performance for the H2 evolution. The combination of PPy and Ni forms a synergistic effect for the rapid trapping and removal of proton from solution and the catalytic reduction of proton to hydrogen. The PPy-functionalized Ni foam could be applied in photocatalytic and photoelectrochemical generation of H2. In all, we report a low cost, high efficient and earth abundant PPy-functionalized Ni foam with a satisfactory catalytic activities comparable to Pt for the practical application of poly-generation of hydrogen and electricity.

  19. Catalytic reduction of nitrate and nitrite ions by hydrogen : investigation of the reaction mechanism over Pd and Pd-Cu catalysts

    NARCIS (Netherlands)

    Ilinitch, OM; Nosova, LV; Gorodetskii, VV; Ivanov, VP; Trukhan, SN; Gribov, EN; Bogdanov, SV; Cuperus, FP

    2000-01-01

    The catalytic behavior of mono- and bimetallic catalysts with Pd and/or Cu supported over gamma-Al2O3 in the reduction of aqueous nitrate and nitrite ions by hydrogen was investigated. The composition of the supported metal catalysts was analysed using secondary ion mass spectroscopy (SIMS) and X-ra

  20. Molybdatophosphoric acid as an efficient catalyst for the catalytic and chemoselective oxidation of sulfides to sulfoxides using urea hydrogen peroxide as a commercially available oxidant

    Directory of Open Access Journals (Sweden)

    ALIREZA HASANINEJAD

    2010-03-01

    Full Text Available An efficient procedure for the chemoselective oxidation of alkyl (aryl sulfides to the corresponding sulfoxides using urea hydrogen peroxide (UHP in the presence of a catalytic amount of molybdatophosphoric acid at room temperature is described. The advantages of described method are: generality, high yield and chemoselectivity, short reaction time, low cost and compliment with green chemistry protocols.

  1. Catalytic enantioselective addition of hydrogen cyanide to benzaldehyde and p-methoxybenzaldehyde using cyclo-His-(αMe)Phe as catalyst

    NARCIS (Netherlands)

    Hulst, Ron; Broxterman, Quirinus B.; Kamphuis, Johan; Formaggio, Fernando; Crisma, Marco; Toniolo, Claudio; Kellogg, Richard M.

    1997-01-01

    Two cyclo-dipeptides based on His and the unnatural (αMe)Phe have been examined as catalysts in the enantioselective addition of hydrogen cyanide to benzaldehyde and p-methoxy-benzaldehyde. The synthesis, catalytic activity and NMR study towards the mechanism of this reaction are presented.

  2. Catalytic enantioselective addition of hydrogen cyanide to benzaldehyde and p-methoxybenzaldehyde using cyclo-His-(alpha-Me)Phe as catalyst

    NARCIS (Netherlands)

    Hulst, R; Broxterman, QB; Kamphuis, J; Formaggio, F; Crisma, M; Toniolo, C; Kellogg, RM

    1997-01-01

    Two cyclo-dipeptides based on His and the unnatural (alpha Me)Phe have been examined as catalysts in the enantioselective addition of hydrogen cyanide to benzaldehyde and p-methoxy-benzaldehyde. The synthesis, catalytic activity and NMR study towards the mechanism of this reaction are presented. (C)

  3. Protons and pleomorphs: aerobic hydrogen production in Azotobacters.

    Science.gov (United States)

    Noar, Jesse D; Bruno-Bárcena, José M

    2016-02-01

    As obligate aerobic soil organisms, the ability of Azotobacter species to fix nitrogen is unusual given that the nitrogenase complex requires a reduced cellular environment. Molecular hydrogen is an unavoidable byproduct of the reduction of dinitrogen; at least one molecule of H2 is produced for each molecule of N2 fixed. This could be considered a fault in nitrogenase efficiency, essentially a waste of energy and reducing equivalents. Wild-type Azotobacter captures this hydrogen and oxidizes it with its membrane-bound uptake hydrogenase complex. Strains lacking an active hydrogenase complex have been investigated for their hydrogen production capacities. What is the role of H2 in the energy metabolism of nitrogen-fixing Azotobacter? Is hydrogen production involved in Azotobacter species' protection from or tolerance to oxygen, or vice versa? What yields of hydrogen can be expected from hydrogen-evolving strains? Can the yield of hydrogen be controlled or increased by changing genetic, environmental, or physiological conditions? We will address these questions in the following mini-review.

  4. Production of Co, Ni, and Cu nanoparticles by hydrogen reduction

    OpenAIRE

    Forsman, Johanna

    2013-01-01

    In this thesis, production of Co, Ni, and Cu nanoparticles by hydrogen reduction of metal chlorides in gas phase was studied. Nanoparticles have unique properties not found in bulk or micron-scale materials. These enable new products or reduced use of raw materials. Metal nanoparticle production has been studied widely, but especially for coated metal particles, research of coating mechanisms and economic production methods is still needed. The method used in this thesis combines a high yield...

  5. Discovery of Photocatalysts for Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    D. Brent MacQueen

    2006-10-01

    This project for DOE was designed to address these materials-related issues through a combination of high-throughput screening of semiconductor candidates and theoretical modeling of nanostructures. High-throughput screening is an effective and economical way to examine a large number of candidates and identify those worthy of further study. Unfortunately, in the course of this project, we discovered no semiconductor candidates that can meet the DOE’s stringent requirements for an economically feasible photoelectrochemical process. However, some of our results indicated that several systems may have potential if further optimized. In particular, the published theoretical modeling work indicates that core-shell nanorod structures, if properly engineered, have the potential to overcome the shortfalls of current semiconductors. Although the synthesis of the designed core-shell nanorod structures proved to be beyond the current capabilities of our laboratories, recent advances in the synthesis of core-shell nanorod structures imply that the designed structures can be synthesized. SRI is confident that once these materials are made they will validate our models and lead to economical and environmentally friendly hydrogen from sunlight and water. The high-throughput photolysis analysis module developed at SRI will also have utility in applications such as identifying catalysts for photo-assisted chemical detoxification, as well as non-photolytic applications such as hydrogen storage, which can take advantage of the ability of the analysis module to monitor pressure over time.

  6. Renewable hydrogen production. The role of Solar Thermal Water Splitting

    OpenAIRE

    Vicens García, Gabriel

    2011-01-01

    In a context of environmental crisis and depletion of conventional energy resources, the current energy model based on fossil fuels is obsolete and needs to be redefined and redesigned. Hydrogen economy can represent a good alternative. To get it, developing carbon-free renewable hydrogen production processes will be crucial. This Master Thesis is focused on the ones using solar thermal energy to split water. At first, world’s energy situation is analyzed to introduce the need of ...

  7. Catalytic Conversion of Lignin for the Production of Aromatics

    NARCIS (Netherlands)

    Jongerius, A.L.

    2013-01-01

    With the depletion of fossil fuels and increasing environmental awareness, there is much interest in the use of biomass as a more sustainable alternative feedstock for the production of renewable fuels and chemicals. Non-edible lignocellulosic biomass is the major and most sustainable source of biom

  8. Hydrogen production from marine biomass by hydrothermal gasification

    International Nuclear Information System (INIS)

    Highlights: • Supercritical water gasification of Posidonia oceanica was studied. • The output was mainly composed of hydrogen, methane and carbon dioxide. • Maximum hydrogen yield was obtained with biomass loading of 0.08 (g/mL) at 600 °C. • Maximum hydrogen and methane yields were 10.37 and 6.34 mol/kg, respectively. • The results propose an alternative solution to the landfill of marine biomass. - Abstract: The hydrothermal gasification of Posidonia oceanica was investigated in a batch reactor without adding any catalysts. The experiments were carried out in the temperature range of 300–600 °C with different biomass loading ranges of 0.04–0.12 (g/mL) in the reaction time of 1 h. The product gas was composed of hydrogen, methane, carbon dioxide, carbon monoxide and a small amount of C2–C4 compounds. The results showed that the formation of gaseous products, gasification efficiency and yield distribution of produced gases were intensively affected by biomass loading and temperature. The yields of hydrogen (10.37 mol/kg) and methane (6.34 mol/kg) were attained at 600 °C using biomass loading of 0.08 (g/mL). The results are very promising in terms of deployment of the utilization of marine biomass for hydrogen and/or methane production to industrial scale applications, thereby proposing an alternative solution to the landfill of P. oceanica residues

  9. Hydrogen production and storage: R & D priorities and gaps

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-05-04

    This review of priorities and gaps in hydrogen production and storage R & D has been prepared by the IEA Hydrogen Implementing Agreement in the context of the activities of the IEA Hydrogen Co-ordination Group. It includes two papers. The first is by Trygve Riis, Elisabet F. Hagen, Preben J.S. Vie and Oeystein Ulleberg. This offers an overview of the technologies for hydrogen production. The technologies discussed are reforming of natural gas; gasification of coal and biomass; and the splitting of water by water-electrolysis, photo-electrolysis, photo-biological production and high-temperature decomposition. The second paper is by Trygve Riis, Gary Sandrock, Oeystein Ulleberg and Preben J.S. Vie. The objective of this paper is to provide a brief overview of the possible hydrogen storage options available today and in the foreseeable future. Hydrogen storage can be considered for onboard vehicular, portable, stationary, bulk, and transport applications, but the main focus of this paper is on vehicular storage, namely fuel cell or ICE/electric hybrid vehicles. 7 refs., 24 figs., 14 tabs.

  10. Photosynthetic hydrogen and oxygen production by green algae

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, E.; Lee, J.W.

    1997-12-31

    An overview of photosynthetic hydrogen and oxygen production by green algae in the context of its potential as a renewable chemical feed stock and energy carrier is presented. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of photosynthesis throughout the entire range of terrestrial solar irradiance--including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transport and (3) the minimum number of light reactions that are required to split water to elemental hydrogen and oxygen. Each of these research topics is being actively addressed by the photobiological hydrogen research community.

  11. New Ruthenium Complexes Based on Tetradentate Bipyridine Ligands for Catalytic Hydrogenation of Esters.

    Science.gov (United States)

    Wang, Fangyuan; Tan, Xuefeng; Lv, Hui; Zhang, Xumu

    2016-08-01

    New bipyridinemethanamine-containing tetradentate ligands and their corresponding ruthenium complexes have been synthesized. The synthesized complexes performed well in the hydrogenation of a variety of esters with high efficiency (TON up to 9700) giving alcohols in good yields. PMID:27385062

  12. Renewable energy from biomass: a sustainable option? - Hydrogen production from alcohols

    Science.gov (United States)

    Balla, Zoltán; Kith, Károly; Tamás, András; Nagy, Orsolya

    2015-04-01

    in the case, than the same volume of ethanol-water mixture can be prepared. The renewal of alcohol, the alcohol-water mixture is then passed through the catalytic reformer into a preheater. The exhaust gas contains a relatively large number of carbon monoxide, which would spoil the fuel cell, so the carbon monoxide concentration to a high and a low temperature water-gas reaction is reduced. This increases the hydrogen production. The last step of the carbon monoxide content to eliminate preferential oxidation. The alcohol reforming catalyst for the precious metals spread most of what arose from high activity and stability. However, the precious metals are very expensive, so a non-precious metal catalysts is the design and development of objective activity and stability which reaches the precious metal catalysts of. Using the new reaction catalysts opportunities are created, which are smaller than the activation energy than the non-catalytic process. The basic objective of the technological developments more active at lower temperatures, the selective target product, long-life, low cost design catalysts.

  13. Effect of inoculum conditioning on hydrogen fermentation and pH effect on bacterial community relevant to hydrogen production.

    Science.gov (United States)

    Kawagoshi, Yasunori; Hino, Naoe; Fujimoto, Aya; Nakao, Masaharu; Fujita, Yukiko; Sugimura, Seiji; Furukawa, Kenji

    2005-11-01

    The effect of conditioning for a variety of inoculums on fermentative hydrogen production was investigated. In addition, the effects of pH condition on hydrogen fermentation and bacterial community were investigated. The effect of conditioning on hydrogen production was different depending on the inoculum types. An appreciable hydrogen production was shown with anaerobic digested sludge and lake sediment without conditioning, however, no hydrogen was produced when refuse compost and kiwi grove soil were used as inoculums without conditioning. The highest hydrogen production was obtained with heat-conditioned anaerobic digested sludge, almost the same production was also obtained with unconditioned digested sludge. The pH condition considerably affected hydrogen fermentation, hydrogen gas was efficiently produced with unconditioned anaerobic sludge when the pH was controlled at 6.0 throughout the culture period and not when only the initial pH was adjusted to 6.0 and 7.0. Hydrogen production decreased when the culture pH was only adjusted at the beginning of each batch in continuous batch culture, and additionally, bacterial community varied with the change in hydrogen production. It was suggested that Clostridium and Coprothermobacter species played important role in hydrogen fermentation, and Lactobacillus species had an adverse effect on hydrogen production.

  14. Kinetic study of biological hydrogen production by anaerobic fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Sangeetha, R. [Annamalai Univ., Chidambaram (India). Dept. of Chemical Engineering; Karunanithi, T. [Annamalai Univ., Tamilnadu (India). Dept. of Chemical Engineering

    2009-07-01

    This study examined the kinetics of batch biohydrogen production from glucose. Clostridium pasteurianum was used to produce biohydrogen by dark anaerobic fermentation. The initial substrate concentration, initial pH and temperature were optimized for biohydrogen production. The maximum production of hydrogen under optimum conditions was found to be 5.376 l/l. The kinetic parameters were determined for the optimized medium and conditions in the batch reactor. The by product was expressed as total acidic equivalent. This presentation discussed the logistic equation that was used to model the growth of the organism and described how the kinetic parameters were calculated. The Leudeking piret kinetic model was used to express the hydrogen production and substrate use because it combines both growth associated and non associated contributions. It was concluded the production of biohydrogen can be predicted well using the logistic model for cell growth kinetics and the logistic incorporated Leudeking Piret model for product and substrate utilization kinetics.

  15. Heavy water in the context of hydrogen economy. Prospects for cheaper production by water electrolysis

    International Nuclear Information System (INIS)

    Hydrogen is an extremely important material. It is commonly used in many industrial processes. It can also be used as the key medium in 'hydrogen energy philosophy' due to its unique energetic properties (production for storage, gas-line transport). Its heavy isotopes, deuterium (D) and tritium (T), are very important nuclear materials. Deuterium, in the form of heavy water, is an excellent moderator in fission reactors, while both D and T are now seen as fuel components in fusion reactors in the future. Thus, improvements of production processes for hydrogen and its isotopes are always actual. Electrolysis (sometimes in combination with other methods) is often used for heavy water production or re-enrichment or for tritium removal from 'nuclear waters', mostly because of high D/H (T/H, T/D) isotope separation factors, although the electrolysis consumes great amounts of energy (about 4.5 to 5 kWh/m3 H2 in industrial electrolyzers). There were various attempts to improve this process: zero-gap cell geometry, development of new diaphragm materials, development of new electrocatalytic materials for electrodes, using so-called ionic activators etc. We investigated the use of catalytic cathode materials made from hypo-hyper-d-electronic combinations of transition metals as well as in situ activation of electrodes. Many intermetallic combinations were tried. Two types of ionic activators were used: tris-(ethylenediamine)-Co(III)-chloride complex and tris-(trimethylenediamine)-Co(III)-chloride complex. Some significant increases of the separation factors were obtained. Dependence of isotope enrichment on the amount of water that must be electrolysed for was estimated for different values of the separation factor. It was concluded that this a good way to increase the efficiency of the process by achieving an energy saving and an increase of the separation factors simultaneously. The method is discussed in a context that assumes heavy water as a by-product of the hydrogen

  16. Challenges for renewable hydrogen production from biomass

    International Nuclear Information System (INIS)

    The increasing demand for H2 for heavy oil upgrading, desulfurization and upgrading of conventional petroleum, and for production of ammonium, in addition to the projected demand for H2 as a transportation fuel and portable power, will require H2 production on a massive scale. Increased production of H2 by current technologies will consume greater amounts of conventional hydrocarbons (primarily natural gas), which in turn will generate greater greenhouse gas emissions. Production of H2 from renewable sources derived from agricultural or other waste streams offers the possibility to contribute to the production capacity with lower or no net greenhouse gas emissions (without carbon sequestration technologies), increasing the flexibility and improving the economics of distributed and semi-centralized reforming. Electrolysis, thermocatalytic, and biological production can be easily adapted to on-site decentralized production of H2, circumventing the need to establish a large and costly distribution infrastructure. Each of these H2 production technologies, however, faces technical challenges, including conversion efficiencies, feedstock type, and the need to safely integrate H2 production systems with H2 purification and storage technologies. (author)

  17. 40 CFR 415.330 - Applicability; description of the carbon monoxide and by-product hydrogen production subcategory.

    Science.gov (United States)

    2010-07-01

    ... carbon monoxide and by-product hydrogen production subcategory. 415.330 Section 415.330 Protection of... MANUFACTURING POINT SOURCE CATEGORY Carbon Monoxide and By-Product Hydrogen Production Subcategory § 415.330 Applicability; description of the carbon monoxide and by-product hydrogen production subcategory. The...

  18. EVermont Renewable Hydrogen Production and Transportation Fueling System

    Energy Technology Data Exchange (ETDEWEB)

    Garabedian, Harold T.

    2008-03-30

    A great deal of research funding is being devoted to the use of hydrogen for transportation fuel, particularly in the development of fuel cell vehicles. When this research bears fruit in the form of consumer-ready vehicles, will the fueling infrastructure be ready? Will the required fueling systems work in cold climates as well as they do in warm areas? Will we be sure that production of hydrogen as the energy carrier of choice for our transit system is the most energy efficient and environmentally friendly option? Will consumers understand this fuel and how to handle it? Those are questions addressed by the EVermont Wind to Wheels Hydrogen Project: Sustainable Transportation. The hydrogen fueling infrastructure consists of three primary subcomponents: a hydrogen generator (electrolyzer), a compression and storage system, and a dispenser. The generated fuel is then used to provide transportation as a motor fuel. EVermont Inc., started in 1993 by then governor Howard Dean, is a public-private partnership of entities interested in documenting and advancing the performance of advanced technology vehicles that are sustainable and less burdensome on the environment, especially in areas of cold climates, hilly terrain and with rural settlement patterns. EVermont has developed a demonstration wind powered hydrogen fuel producing filling system that uses electrolysis, compression to 5000 psi and a hydrogen burning vehicle that functions reliably in cold climates. And that fuel is then used to meet transportation needs in a hybrid electric vehicle whose internal combustion engine has been converted to operate on hydrogen Sponsored by the DOE EERE Hydrogen, Fuel Cells & Infrastructure Technologies (HFC&IT) Program, the purpose of the project is to test the viability of sustainably produced hydrogen for use as a transportation fuel in a cold climate with hilly terrain and rural settlement patterns. Specifically, the project addresses the challenge of building a renewable

  19. Catalytic conversion of biomass-derived feedstocks into olefins and aromatics with ZSM-5: the hydrogen to carbon effective ratio

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Huiyan; Cheng, Yu-Ting; Vispute, Tushar; Xiao, R; Huber, George W.

    2011-01-01

    Catalytic conversion of ten biomass-derived feedstocks, i.e.glucose, sorbitol, glycerol, tetrahydrofuran, methanol and different hydrogenated bio-oil fractions, with different hydrogen to carbon effective (H/C{sub eff}) ratios was conducted in a gas-phase flow fixed-bed reactor with a ZSM-5 catalyst. The aromatic + olefin yield increases and the coke yield decreases with increasing H/C{sub eff} ratio of the feed. There is an inflection point at a H/C{sub eff} ratio = 1.2, where the aromatic + olefin yield does not increase as rapidly as it does prior to this point. The ratio of olefins to aromatics also increases with increasing H/C{sub eff} ratio. CO and CO₂ yields go through a maximum with increasing H/C{sub eff} ratio. The deactivation rate of the catalyst decreases significantly with increasing H/C{sub eff} ratio. Coke was formed from both homogeneous and heterogeneous reactions. Thermogravimetric analysis (TGA) for the ten feedstocks showed that the formation of coke from homogeneous reactions decreases with increasing H/C{sub eff} ratio. Feedstocks with a H/C{sub eff} ratio less than 0.15 produce large amounts of undesired coke (more than 12 wt%) from homogeneous decomposition reactions. This paper shows that the conversion of biomass-derived feedstocks into aromatics and olefins using zeolite catalysts can be explained by the H/C{sub eff} ratio of the feed.

  20. Experimental studies on catalytic hydrogen recombiners for light water reactors; Experimentelle Untersuchungen zu katalytischen Wasserstoffkombinatoren fuer Leichtwasserreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Drinovac, P.

    2006-06-19

    In the course of core melt accidents in nuclear power plants a large amount of hydrogen can be produced and form an explosive or even detonative gas mixture with aerial oxygen in the reactor building. In the containment atmosphere of pressurized water reactors hydrogen combines a phlogistically with the oxygen present to form water vapor even at room temperature. In the past, experimental work conducted at various facilities has contributed little or nothing to an understanding of the operating principles of catalytic recombiners. Hence, the purpose of the present study was to conduct detailed investigations on a section of a recombiner essentially in order to deepen the understanding of reaction kinetics and heat transport processes. The results of the experiments presented in this dissertation form a large data base of measurements which provides an insight into the processes taking place in recombiners. The reaction-kinetic interpretation of the measured data confirms and deepens the diffusion theory - proposed in an earlier study. Thus it is now possible to validate detailed numeric models representing the processes in recombiners. Consequently the present study serves to broaden and corroborate competence in this significant area of reactor technology. In addition, the empirical knowledge thus gained may be used for a critical reassessment of previous numeric model calculations. (orig.)

  1. Sub-10 nm Platinum Nanocrystals with Size and Shape Control: Catalytic Study for Ethylene and Pyrrole Hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Tsung, Chia-Kuang; Kuhn, John N.; Huang, Wenyu; Aliaga, Cesar; Hung, Ling-I; Somorjai, Gabor A.; Yang, Peidong

    2009-03-02

    Platinum nanocubes and nanopolyhedra with tunable size from 5 to 9 nm were synthesized by controlling the reducing rate of metal precursor ions in a one-pot polyol synthesis. A two-stage process is proposed for the simultaneous control of size and shape. In the first stage, the oxidation state of the metal ion precursors determined the nucleation rate and consequently the number of nuclei. The reaction temperature controlled the shape in the second stage by regulation of the growth kinetics. These well-defined nanocrystals were loaded into MCF-17 mesoporous silica for examination of catalytic properties. Pt loadings and dispersions of the supported catalysts were determined by elemental analysis (ICP-MS) and H2 chemisorption isotherms, respectively. Ethylene hydrogenation rates over the Pt nanocrystals were independent of both size and shape and comparable to Pt single crystals. For pyrrole hydrogenation, the nanocubes enhanced ring-opening ability and thus showed a higher selectivity to n-butylamine as compared to nanopolyhedra.

  2. Photovoltaic hydrogen production with commercial alkaline electrolysers

    Energy Technology Data Exchange (ETDEWEB)

    Ursua, A.; Lopez, J.; Gubia, E.; Marroyo, L.; Sanchis, P. [Public Univ. of Navarra, Pamplona (Spain). Dept. of Electric and Electronic Engineering

    2010-07-01

    Renewable energy sources and Electrolysis generate the so-called green Hydrogen, a zero-emission and potentially fossil fuel independent energy source. However, the inherent variability of the renewable energy sources implies a mode of operation for which most current electrolysers have not been designed. This paper analyses the operation of a water electrolyser fed with photovoltaic (PV) generator electric profile. The system, Integrated by a 1 Nm{sup 3}/h Hydrogenics alkaline electrolyser and a 5100 W PV generator with 60 BP585 modules, is installed at the Public University of Navarra (Spain). The PV generator profile fed to the electrolyser is emulated by a custom-made apparatus designed and built by the authors of this paper. The profile is designed according to real irradiance data measured by a calibration cell. The irradiance data are converted to the electric power profile that the PV generator would have delivered in case of having been connected to the electrolyser by means of a DC/DC converter with maximum power point tracking (MPPT). Finally, from previously measured power-current electrolyser characteristic curves, the current profile to be delivered to the electrolyser is obtained and programmed to the electronic device. The electrolyser was tested for two types of days. During the first day, the irradiance was very stable, whereas during the second day, the irradiance was very variable. The experimental results show an average power consumption rate and an efficiency of 4908 Wh/Nm{sup 3} and 72.1%, on the first day, and 4842 Wh/Nm{sup 3} and 73.3% on the second day. The electrolyser performance was particularly good in spite of the high variability of the electric supply of the second day. (orig.)

  3. Dendrimer Templated Synthesis of One Nanometer Rh and Pt Particles Supported on Mesoporous Silica: Catalytic Activity for Ethylene and Pyrrole Hydrogenation.

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Wenyu; Kuhn, John N.; Tsung, Chia-Kuang; Zhang, Yawen; Habas, Susan E.; Yang, Peidong; Somorjai, Gabor A.

    2008-05-09

    Monodisperse rhodium (Rh) and platinum (Pt) nanoparticles as small as {approx}1 nm were synthesized within a fourth generation polyaminoamide (PAMAM) dendrimer, a hyperbranched polymer, in aqueous solution and immobilized by depositing onto a high-surface-area SBA-15 mesoporous support. X-ray photoelectron spectroscopy indicated that the as-synthesized Rh and Pt nanoparticles were mostly oxidized. Catalytic activity of the SBA-15 supported Rh and Pt nanoparticles was studied with ethylene hydrogenation at 273 and 293 K in 10 torr of ethylene and 100 torr of H{sub 2} after reduction (76 torr of H{sub 2} mixed with 690 torr of He) at different temperatures. Catalysts were active without removing the dendrimer capping but reached their highest activity after hydrogen reduction at a moderate temperature (423 K). When treated at a higher temperature (473, 573, and 673 K) in hydrogen, catalytic activity decreased. By using the same treatment that led to maximum ethylene hydrogenation activity, catalytic activity was also evaluated for pyrrole hydrogenation.

  4. Experimental and Computational Mechanistic Studies Guiding the Rational Design of Molecular Electrocatalysts for Production and Oxidation of Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Raugei, Simone; Helm, Monte L.; Hammes-Schiffer, Sharon; Appel, Aaron M.; O' Hagan, Molly J.; Wiedner, Eric S.; Bullock, R. Morris

    2016-01-19

    Understanding how to control the movement of protons and electrons is crucial to the design of fast, efficient electrocatalysts for hydrogen production and oxidation based on earth-abundant metals. Our work seeks to elucidate fundamental questions about proton movement. We have demonstrated that incorporating a pendant amine functioning as a proton relay in the second coordination sphere of a metal complex helps proton mobility, resulting in faster and more energy efficient catalysts. Proton transfer reactions are often rate limiting, and are influenced by several factors, such as pKa values, steric effects, hydrogen bonding, and solvation/desolvation of the exogenous base and acid employed. The presence of multiple protonation sites introduces branching points along the catalytic cycle, making less productive pathways accessible, or leading to the formation of stable off-cycle species. Using ligands with only one pendant amine mitigates this problem and results in catalysts with high rates for production of H2. For H2 oxidation catalysts, iron complexes with a high H2 binding affinity were developed. However, the improvement of H2 binding enthalpy resulted in a pKa mismatch between the protonated metal center and the protonated pendant amine, and consequently to rate-limiting intramolecular proton movement. Taken altogether, our results demonstrate the necessity of optimizing the entire catalytic cycle, as the optimization of a specific catalytic step can negatively influence another step, and not necessarily lead to better catalytic performance. We discuss a general procedure, based on thermodynamic arguments, which allows the simultaneous minimization of the free energy change of each catalytic step, yielding a nearly flat free energy surface, with no large barriers due to energy mismatches from either high- or low-energy intermediates. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by

  5. Media Improvement for Hydrogen Production Using C. acetobutylicum NCIMB 13357

    Directory of Open Access Journals (Sweden)

    Mohd S. Kalil

    2009-01-01

    Full Text Available Problem statement: Some component of fermentation medium showed to reduce the bacterial production of hydrogen. Approach: Reinforced clostridium medium is a selected medium for Clostridium species. Reformulation this medium regarding hydrogen production may focus on such medium composition that enhance or reduce the bacterial productivity. The optimum pH and temperature for hydrogen production were at initial pH of 7.0 and 30°C. Results: The results show that both nitrogen source and its concentration affected biomass growth as well as H2 yield. Yeast extract at concentration of 13 gL-1 was the best organic nitrogen source and resulted in hydrogen yield (YP/S of 308 mL g-1 glucose utilized with biomass concentration of 1.1 gL-1, hydrogen yield per biomass (YP/X of 280 mL g-1 L-1, biomass per substrate utilized (YX/S of 0.22 and produced hydrogen in gram per gram of glucose utilized (YH2/S of 0.0275. C/N of 70 enhanced the YP/S from 308 mL g-1 to 350 mL g-1 glucose utilized with biomass concentration of 1.22 gL-1, YP/X of 287 mL g-1 L-1, YX/S of 0.244 and (YH2/S of 0.03125. In the absence of sodium chloride and sodium acetate further enhanced YP/S from 350 mL g-1 glucose utilized to 391 mL g-1 glucose utilized with maximum hydrogen productivity of 77.5 mL L-1 h-1, whereas RCM medium gave the highest hydrogen productivity of 63.5 mL L-1h-1. Results also show that Sodium Chloride and Sodium Acetate in the medium adversely affect growth. Removal of both components from the medium enhanced the biomass concentration from 1.22-1.34 gL-1, YP/X of 254 mL g-1 L-1, YX/S of 0.268 and (YH2/S of 0.0349. Conclusion: The medium an improved containing (glucose 5 gL-1, Yeast extract gL-1, L-Cystine. HCl 1 gL-1 and Bacteriological agar 0.5 gL-1, was able to enhance the hydrogen productivity.

  6. Effect of ozone pretreatment on hydrogen production from barley straw.

    Science.gov (United States)

    Wu, Jiangning; Ein-Mozaffari, Farhad; Upreti, Simant

    2013-09-01

    Application of ozone technology to lignocellulosic biohydrogen production was explored with a barley straw. Ozone pretreatment effectively degraded the straw lignin and increased reducing sugar yield. A simultaneous enzyme hydrolysis and dark fermentation experiment was conducted using a mixed anaerobic consortium together with saccharification enzymes. Both untreated and ozonated samples produced hydrogen. Compared to the untreated group, hydrogen produced by the groups ozonated for 15, 30, 45 and 90 min increased 99%, 133%, 166% and 94%, respectively. Some inhibitory effect on hydrogen production was observed with the samples ozonated for 90 min, and the inhibition was on the fermentative microorganisms, not the saccharification enzymes. These results demonstrate that production of biohydrogen from barley straw, a lignocellulosic biomass, can be significantly enhanced by ozone pretreatment.

  7. Non-traditional Process of Hydrogen Containing Fuel Mixtures Production for Internal-combustion Engines

    Directory of Open Access Journals (Sweden)

    Gennady G. Kuvshinov

    2012-12-01

    Full Text Available The article justifies the perspectives of development of the environmentally sound technology of hydrogen containing fuel mixtures for internal-combustion engines based on the catalytic process of low-temperature decomposition of hydrocarbons into hydrogen and nanofibrous carbon.

  8. Enhancement of anaerobic hydrogen production by iron and nickel

    Energy Technology Data Exchange (ETDEWEB)

    Karadag, Dogan; Puhakka, Jaakko A. [Department of Chemistry and Bioengineering, Tampere University of Technology, Tampere (Finland)

    2010-08-15

    The effects of iron and nickel on hydrogen (H{sub 2}) production were investigated in a glucose-fed anaerobic Continuous Flow Stirred Tank Reactor (ACSTR). Both iron and nickel improved the reactor performance and H{sub 2} production was enhanced by 71% with the sole iron or nickel supplementation. In all cases, H{sub 2} production yield was increased by lowering both ethanol and total metabolites production and increasing butyrate production. Furthermore, iron and nickel slightly increased biomass production while glucose degradation decreased with the supplementation of nickel. Dynamic changes in bacterial composition as analyzed by 16S rRNA gene-targeted denaturing gradient gel electrophoresis (DGGE) revealed that hydrogen was produced mainly by Clostridium butyricum strains and that nickel addition decreased the microbial diversity. (author)

  9. Development of New Chiral Bicyclic Ligands : Applications in Catalytic Asymmetric Transfer Hydrogenation, Epoxidations, and Epoxide Rearrangements

    OpenAIRE

    Gayet, Arnaud

    2005-01-01

    This thesis describes the synthesis and application of new chiral bicyclic ligands and their application in asymmetric catalysis. The studies involved: [i] The development of novel chiral bicyclic amino sulfur ligands and their use in transfer hydrogenation. [ii] The development of the kinetic resolution of racemic epoxide through the use of chiral lithium amides. [iii] The synthesis and application of chiral bicyclic amine in the organocatalysed epoxidation of alkenes. [iv] Development and a...

  10. Hydrogen production from high-moisture content biomass in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Antal, M.J. Jr.; Adschiri, T.; Ekbom, T. [Univ. of Hawaii, Honolulu, HI (United States)] [and others

    1996-10-01

    Most hydrogen is produced by steam reforming methane at elevated pressures. The goal of this research is to develop commercial processes for the catalytic steam reforming of biomass and other organic wastes at high pressures. This approach avoids the high cost of gas compression and takes advantage of the unique properties of water at high pressures. Prior to this year the authors reported the ability of carbon to catalyze the decomposition of biomass and related model compounds in supercritical water. The product gas consists of hydrogen, carbon dioxide, carbon monoxide, methane, and traces of higher hydrocarbons. During the past year the authors have: (a) developed a method to extend the catalyst life, (b) begun studies of the role of the shift reaction, (c) completed studies of carbon dioxide absorption from the product effluent by high pressure water, (d) measured the rate of carbon catalyst gasification in supercritical water, (e) discovered the pumpability of oil-biomass slurries, and (f) completed the design and begun fabrication of a flow reactor that will steam reform whole biomass feedstocks (i.e. sewage sludge) and produce a hydrogen rich synthesis gas at very high pressure (>22 MPa).

  11. Enhanced-hydrogen gas production through underground gasification of lignite

    Institute of Scientific and Technical Information of China (English)

    LIU Shu-qin; WANG Yuan-yuan; ZHAO Ke; YANG Ning

    2009-01-01

    Underground coal gasification is one of the clean technologies of in-situ coal utilization. Hydrogen production from underground gasification of lignite was investigated in this study based on simulation experiments. Pyrolysis of lignite, gasification activity, oxygen-steam gasification and the effect of groundwater influx were studied. As well, the advantages of lignite for stable underground gasification were analyzed. The results indicate that lignite has a high activity for gasification. Coal pyrolysis is an important source of hydrogen emission. Under special heating conditions, hydrogen is released from coal seams at temperatures above 350 ℃ and reaches its maximum value between 725 and 825 ℃. Gas with a hydrogen concentration of 40% to 50% can be continuously obtained by oxygen-steam injection at an optimum ratio of steam to oxygen, while lignite properties will ensure stable gasification. Groundwater influx can be utilized for hydrogen preparation under certain geological conditions through pressure control. Therefore, enhanced-hydrogen gas production through underground gasification of lignite has experimentally been proved.

  12. CERAMIC MEMBRANES FOR HYDROGEN PRODUCTION FROM COAL

    Energy Technology Data Exchange (ETDEWEB)

    George R. Gavalas

    2001-11-27

    The present project is devoted to developing hydrogen permselective silica membranes supported on composite supports to achieve high flux and selectivity. The supports consist of a thin zeolite silicalite layer coated on {alpha}-Al{sub 2}O{sub 3} tubes of mean pore size 1 {micro}m. The zeolite layer is grown by reaction in a suitable silicate solution at 95 C. After two or three reaction periods a layer of silicalite crystals about 20 {micro}m thick grows inside the pores of alumina. In addition to the zeolitic pores, this layer contains voids of a few nanometer diameter that remain between the crystals or between the crystals and the pore walls. The quality of the silicalite/alumina composites was evaluated by gas permeation measurements and by nitrogen adsorption and it was found that the residual voids were below 5 nm in diameter. Three techniques were investigated for chemical vapor deposition (CVD) of the silica layer on the silicalite/alumina composite support. The first was TEOS pyrolysis at approximately one millibar partial pressure and 650 C. After 8 h reaction the fluxes of hydrogen and nitrogen at ambient temperature had declined by a factor of approximately 100 indicating sealing of defects and zeolitic pores alike. The second CVD technique investigated was SiCl{sub 4} hydrolysis at 90 C. Deposition in this case was conducted in a series of cycles, each cycle comprising two half reactions, i.e. exposure to SiCl{sub 4} followed by exposure to water vapor. The deposition was interrupted every five cycles to measure the permeation properties of the nascent membrane at 120 C. After a few cycles the membrane pores were sealed, but the silica layer was not thermally stable when the temperature was raised to 400 C. In the third technique investigated, silica deposition was carried out by SiCl{sub 4} hydrolysis at 400 C, again in a sequence of half reaction cycles. After 15 cycles the membrane pores were well sealed by a layer stable to at least 400 C.

  13. Biomedical and Forensic Applications of Combined Catalytic Hydrogenation-Stable Isotope Ratio Analysis

    Directory of Open Access Journals (Sweden)

    Mark A. Sephton

    2007-01-01

    Full Text Available Studies of biological molecules such as fatty acids and the steroid hormones have the potential to benefit enormously from stable carbon isotope ratio measurements of individual molecules. In their natural form, however, the body’s molecules interact too readily with laboratory equipment designed to separate them for accurate measurements to be made.Some methods overcome this problem by adding carbon to the target molecule, but this can irreversibly overprint the carbon source ‘signal’. Hydropyrolysis is a newly-applied catalytic technique that delicately strips molecules of their functional groups but retains their carbon skeletons and stereochemistries intact, allowing precise determination of the carbon source. By solving analytical problems, the new technique is increasing the ability of scientists to pinpoint molecular indicators of disease, elucidate metabolic pathways and recognise administered substances in forensic investigations.

  14. CFD simulation of hydrogen mixing and mitigation by means of passive auto-catalytic recombiners

    Energy Technology Data Exchange (ETDEWEB)

    Kelm, S.; Reinecke, E-A.; Jahn, W., E-mail: s.kelm@fz-juelich.de [Forschungszentrum Juelich GmbH, Juelich (Germany); Allelein, H-J. [RWTH Aachen Univ.. Aachen (Germany)

    2011-07-01

    Modeling of passive auto-catalytic recombiners (PARs) operation in containment geometries involves a large variety of scales; thus, a CFD calculation resolving all these scales would be much too expensive. Therefore, the mechanistic PAR model REKO-DIREKT, developed at Forschungszentrum Juelich, has been coupled with the commercial CFD code ANSYS CFX in order to simulate PAR operation as well as the induced flow and transport phenomena. Based on a short introduction of REKO-DIREKT, its interface to CFX and the explicit coupling scheme is discussed. The paper is finalized by a first demonstration of simulation capabilities on the basis of the ThAI PAR-4 experiment (Becker Technologies GmbH, Eschborn, Germany). (author)

  15. [Activity of hydrogen sulfide production enzymes in kidneys of rats].

    Science.gov (United States)

    Mel'nyk, A V; Pentiuk, O O

    2009-01-01

    An experimental research of activity and kinetic descriptions of enzymes participating in formation of hydrogen sulfide in the kidney of rats has been carried out. It was established that cystein, homocystein and thiosulphate are the basic substrates for hydrogen sulfide synthesis. The higest activity for hydrogen sulfide production belongs to thiosulfate-dithiolsulfurtransferase and cysteine aminotransferase, less activity is characteristic of cystathionine beta-synthase and cystathio-nine gamma-lyase. The highest affinity to substrate is registered for thiosulfate-dithiolsulfurtransferase and cystathionine gamma-lyase. It is discovered that the substrate inhibition is typical of all hydrogen sulfide formation enzymes, although this characteristic is the most expressed thiosulfat-dithiolsulfurtransferase. PMID:20387629

  16. Studies on membrane acid electrolysis for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marco Antonio Oliveira da; Linardi, Marcelo; Saliba-Silva, Adonis Marcelo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Celulas a Combustivel e Hidrogenio], Email: saliba@ipen.br

    2010-07-01

    Hydrogen represents great opportunity to be a substitute for fossil fuels in the future. Water as a renewable source of hydrogen is of great interest, since it is abundant and can decompose, producing only pure H{sub 2} and O{sub 2}. This decomposition of water can be accomplished by processes such as electrolysis, thermal decomposition and thermochemical cycles. The electrolysis by membrane has been proposed as a viable process for hydrogen production using thermal and electrical energy derived from nuclear energy or any renewable source like solar energy. In this work, within the context of optimization of the electrolysis process, it is intended to develop a mathematical model that can simulate and assist in parameterization of the electrolysis performed by polymer membrane electrolytic cell. The experimental process to produce hydrogen via the cell membrane, aims to optimize the amount of gas produced using renewable energy with noncarbogenic causing no harm by producing gases deleterious to the environment. (author)

  17. Bio-syngas production from biomass catalytic gasification

    International Nuclear Information System (INIS)

    A promising application for biomass is liquid fuel synthesis, such as methanol or dimethyl ether (DME). Previous studies have studied syngas production from biomass-derived char, oil and gas. This study intends to explore the technology of syngas production from direct biomass gasification, which may be more economically viable. The ratio of H2/CO is an important factor that affects the performance of this process. In this study, the characteristics of biomass gasification gas, such as H2/CO and tar yield, as well as its potential for liquid fuel synthesis is explored. A fluidized bed gasifier and a downstream fixed bed are employed as the reactors. Two kinds of catalysts: dolomite and nickel based catalyst are applied, and they are used in the fluidized bed and fixed bed, respectively. The gasifying agent used is an air-steam mixture. The main variables studied are temperature and weight hourly space velocity in the fixed bed reactor. Over the ranges of operating conditions examined, the maximum H2 content reaches 52.47 vol%, while the ratio of H2/CO varies between 1.87 and 4.45. The results indicate that an appropriate temperature (750 oC for the current study) and more catalyst are favorable for getting a higher H2/CO ratio. Using a simple first order kinetic model for the overall tar removal reaction, the apparent activation energies and pre-exponential factors are obtained for nickel based catalysts. The results indicate that biomass gasification gas has great potential for liquid fuel synthesis after further processing

  18. Human Cystathionine-β-Synthase Phosphorylation on Serine227 Modulates Hydrogen Sulfide Production in Human Urothelium.

    Directory of Open Access Journals (Sweden)

    Roberta d'Emmanuele di Villa Bianca

    Full Text Available Urothelium, the epithelial lining the inner surface of human bladder, plays a key role in bladder physiology and pathology. It responds to chemical, mechanical and thermal stimuli by releasing several factors and mediators. Recently it has been shown that hydrogen sulfide contributes to human bladder homeostasis. Hydrogen sulfide is mainly produced in human bladder by the action of cystathionine-β-synthase. Here, we demonstrate that human cystathionine-β-synthase activity is regulated in a cGMP/PKG-dependent manner through phosphorylation at serine 227. Incubation of human urothelium or T24 cell line with 8-Bromo-cyclic-guanosine monophosphate (8-Br-cGMP but not dibutyryl-cyclic-adenosine monophosphate (d-cAMP causes an increase in hydrogen sulfide production. This result is congruous with the finding that PKG is robustly expressed but PKA only weakly present in human urothelium as well as in T24 cells. The cGMP/PKG-dependent phosphorylation elicited by 8-Br-cGMP is selectively reverted by KT5823, a specific PKG inhibitor. Moreover, the silencing of cystathionine-β-synthase in T24 cells leads to a marked decrease in hydrogen sulfide production either in basal condition or following 8-Br-cGMP challenge. In order to identify the phosphorylation site, recombinant mutant proteins of cystathionine-β-synthase in which Ser32, Ser227 or Ser525 was mutated in Ala were generated. The Ser227Ala mutant cystathionine-β-synthase shows a notable reduction in basal biosynthesis of hydrogen sulfide becoming unresponsive to the 8-Br-cGMP challenge. A specific antibody that recognizes the phosphorylated form of cystathionine-β-synthase has been produced and validated by using T24 cells and human urothelium. In conclusion, human cystathionine-β-synthase can be phosphorylated in a PKG-dependent manner at Ser227 leading to an increased catalytic activity.

  19. Large scale synthesis of CdS nanorods and its utilization in photo-catalytic H{sub 2} production

    Energy Technology Data Exchange (ETDEWEB)

    Janet, C M; Viswanath, R P [Department of Chemistry, Indian Institute of Technology Madras, Chennai-600036 (India)

    2006-10-28

    CdS nanorods along with nanostrips and plates have been prepared on a large scale by the solvothermal route using the precursor cadmium oxalate under mild conditions with ethylene glycol as the solvent and (NH{sub 4}){sub 2}S as the sulfiding agent, without using catalysts, surfactants or template. The aspect ratio of the rods varied from 3 to 30. Characterization has been done by TEM, HR-TEM, EDX, HR-SEM, XRD, BET surface area, UV-vis absorption, photoluminescence and fluorescence studies. Photo-catalytic H{sub 2} production activity was tested with as-synthesized CdS, calcined CdS, noble metal loaded CdS and for bulk CdS. The nanorods being formed are used as such for H{sub 2} production. The as-synthesized CdS is found to have very good H{sub 2} production capacity compared to that of the bulk CdS. Upon Pt loading much enhanced activity was observed in the rate of hydrogen production.

  20. Hydrogen production through nuclear energy, a sustainable scenario in Mexico

    International Nuclear Information System (INIS)

    The energy is a key point in the social and economic development of a country, for such motive to assure the energy supply in Mexico it is of vital importance. The hydrogen it is without a doubt some one of the alternating promising fuels before the visible one necessity to decentralize the energy production based on hydrocarbons. The versatility of their applications, it high heating power and having with the more clean fuel cycle of the energy basket with which count at the moment, they are only some examples of their development potential. However the more abundant element of the universe it is not in their elementary form in our planet, it forms molecules like in the hydrocarbons or water and it stops their use it should be extracted. At the present time different methods are known for the extraction of hydrogen, there is thermal, electric, chemical, photovoltaic among others. The election of the extraction method and the primary energy source to carry out it are decisive to judge the sustainability of the hydrogen production. The sustainable development is defined as development that covers the present necessities without committing the necessity to cover the necessities of the future generations, and in the mark of this definition four indicators of the sustainable development of the different cycles of fuel were evaluated in the hydrogen production in Mexico. These indicators take in consideration the emissions of carbon dioxide in the atmosphere (environment), the readiness of the energy resources (technology), the impacts in the floor use (social) and the production costs of the cycles (economy). In this work the processes were studied at the moment available for the generation of hydrogen, those that use coal, natural gas, hydraulic, eolic energy, biomass and nuclear, as primary energy sources. These processes were evaluated with energy references of Mexico to obtain the best alternative for hydrogen production. (Author)

  1. Study on hydrogen production by high temperature electrolysis of steam

    International Nuclear Information System (INIS)

    In JAERI, design and R and D works on hydrogen production process have been conducted for connecting to the HTTR under construction at the Oarai Research Establishment of JAERI as a nuclear heat utilization system. As for a hydrogen production process by high-temperature electrolysis of steam, laboratory-scale experiments were carried out with a practical electrolysis tube with 12 cells connected in series. Hydrogen was produced at a maximum density of 44 Nml/cm2h at 950degC, and know-how of operational procedures and operational experience were also accumulated. Thereafter, a planar electrolysis cell supported by a metallic plate was fabricated in order to improve hydrogen production performance and durability against thermal cycles. In the preliminary test with the planar cell, hydrogen has been produced continuously at a maximum density of 33.6 Nml/cm2h at an electrolysis temperature of 950degC. This report presents typical test results mentioned above, a review of previous studies conducted in the world and R and D items required for connecting to the HTTR. (author)

  2. Analytical approaches to photobiological hydrogen production in unicellular green algae.

    Science.gov (United States)

    Hemschemeier, Anja; Melis, Anastasios; Happe, Thomas

    2009-01-01

    Several species of unicellular green algae, such as the model green microalga Chlamydomonas reinhardtii, can operate under either aerobic photosynthesis or anaerobic metabolism conditions. A particularly interesting metabolic condition is that of "anaerobic oxygenic photosynthesis", whereby photosynthetically generated oxygen is consumed by the cell's own respiration, causing anaerobiosis in the culture in the light, and induction of the cellular "hydrogen metabolism" process. The latter entails an alternative photosynthetic electron transport pathway, through the oxygen-sensitive FeFe-hydrogenase, leading to the light-dependent generation of molecular hydrogen in the chloroplast. The FeFe-hydrogenase is coupled to the reducing site of photosystem-I via ferredoxin and is employed as an electron-pressure valve, through which electrons are dissipated, thus permitting a sustained electron transport in the thylakoid membrane of photosynthesis. This hydrogen gas generating process in the cells offers testimony to the unique photosynthetic metabolism that can be found in many species of green microalgae. Moreover, it has attracted interest by the biotechnology and bioenergy sectors, as it promises utilization of green microalgae and the process of photosynthesis in renewable energy production. This article provides an overview of the principles of photobiological hydrogen production in microalgae and addresses in detail the process of induction and analysis of the hydrogen metabolism in the cells. Furthermore, methods are discussed by which the interaction of photosynthesis, respiration, cellular metabolism, and H(2) production in Chlamydomonas can be monitored and regulated. PMID:19291418

  3. DOE Hydrogen, Fuel Cells and Infrastructure Technologies Program Integrated Hydrogen Production, Purification and Compression System

    Energy Technology Data Exchange (ETDEWEB)

    Tamhankar, Satish; Gulamhusein, Ali; Boyd, Tony; DaCosta, David; Golben, Mark

    2011-06-30

    The project was started in April 2005 with the objective to meet the DOE target of delivered hydrogen of <$1.50/gge, which was later revised by DOE to $2-$3/gge range for hydrogen to be competitive with gasoline as a fuel for vehicles. For small, on-site hydrogen plants being evaluated at the time for refueling stations (the 'forecourt'), it was determined that capital cost is the main contributor to the high cost of delivered hydrogen. The concept of this project was to reduce the cost by combining unit operations for the entire generation, purification, and compression system (refer to Figure 1). To accomplish this, the Fluid Bed Membrane Reactor (FBMR) developed by MRT was used. The FBMR has hydrogen selective, palladium-alloy membrane modules immersed in the reformer vessel, thereby directly producing high purity hydrogen in a single step. The continuous removal of pure hydrogen from the reformer pushes the equilibrium 'forward', thereby maximizing the productivity with an associated reduction in the cost of product hydrogen. Additional gains were envisaged by the integration of the novel Metal Hydride Hydrogen Compressor (MHC) developed by Ergenics, which compresses hydrogen from 0.5 bar (7 psia) to 350 bar (5,076 psia) or higher in a single unit using thermal energy. Excess energy from the reformer provides up to 25% of the power used for driving the hydride compressor so that system integration improved efficiency. Hydrogen from the membrane reformer is of very high, fuel cell vehicle (FCV) quality (purity over 99.99%), eliminating the need for a separate purification step. The hydride compressor maintains hydrogen purity because it does not have dynamic seals or lubricating oil. The project team set out to integrate the membrane reformer developed by MRT and the hydride compression system developed by Ergenics in a single package. This was expected to result in lower cost and higher efficiency compared to conventional hydrogen production

  4. Designer proton-channel transgenic algae for photobiological hydrogen production

    Science.gov (United States)

    Lee, James Weifu

    2011-04-26

    A designer proton-channel transgenic alga for photobiological hydrogen production that is specifically designed for production of molecular hydrogen (H.sub.2) through photosynthetic water splitting. The designer transgenic alga includes proton-conductive channels that are expressed to produce such uncoupler proteins in an amount sufficient to increase the algal H.sub.2 productivity. In one embodiment the designer proton-channel transgene is a nucleic acid construct (300) including a PCR forward primer (302), an externally inducible promoter (304), a transit targeting sequence (306), a designer proton-channel encoding sequence (308), a transcription and translation terminator (310), and a PCR reverse primer (312). In various embodiments, the designer proton-channel transgenic algae are used with a gas-separation system (500) and a gas-products-separation and utilization system (600) for photobiological H.sub.2 production.

  5. Investigating the potential for energy, fuel, materials and chemicals production from corn residues (cobs and stalks) by non-catalytic and catalytic pyrolysis in two reactor configurations

    Energy Technology Data Exchange (ETDEWEB)

    Ioannidou, O.; Zabaniotou, A. [Chemical Engineering Department, Aristotle University of Thessaloniki, Thessaloniki (Greece); Antonakou, E.V.; Papazisi, K.M.; Lappas, A.A. [Chemical Process Engineering Research Institute (CPERI) (Greece); Athanassiou, C. [Department of Engineering and Management of Energy Resources, University of Western Macedonia (Greece)

    2009-05-15

    The results of thermogravimetric analysis (TGA), non-catalytic and catalytic pyrolysis of corn cobs and corn stalks are reported in this paper. Pyrolysis took place in two different reactor configurations for both feedstocks: (1) fast pyrolysis in a captive sample reactor; and (2) non-catalytic slow pyrolysis and catalytic pyrolysis in a fixed-bed reactor. Experiments were carried out in atmospheric pressure at three temperatures: low temperature (360-380 C), medium temperature (500-600 C) and at high temperature (600-700 C). The results of the experimental study were compared with data reported in the literature. Investigating the potential of corn residues for energy, fuel, materials and chemicals production according to their thermochemical treatment products yields and quality, it can be stated that: (a) corn stalks could be suitable raw material for energy production via gasification at high temperature, due to their medium low heating value (LHV) of pyrolysis gas (13-15 MJ/m{sup 3}); (b) corn cob could be a good solid biofuel, due to the high LHV (24-26 MJ/kg) of the produced char; (c) additionally, corn cobs could be a good material for activated carbon production after being activated or gasified with steam, due to its high fixed carbon content({proportional_to}74 wt%); (d) liquid was the major pyrolysis product from catalytic pyrolysis (about 40-44 wt% on biomass) for both feedstocks; further analysis of the organic phase of the liquid products were hydrocarbons and phenols, which make them interesting for chemicals production. (author)

  6. Calculation of LUEC using HEEP Software for Nuclear Hydrogen Production Plant

    International Nuclear Information System (INIS)

    To achieve the hydrogen economy, it is very important to produce a massive amount of hydrogen in a clean, safe and efficient way. Nuclear production of hydrogen would allow massive production of hydrogen at economic prices while avoiding environments pollution by reducing the release of carbon dioxide. A Very High Temperature Reactor (VHTR) is considered as an efficient reactor to couple with the thermo-chemical Sulfur Iodine (SI) cycle to achieve the hydrogen economy. HEEP(Hydrogen Economy Evaluation Program) is one of the software tools developed by IAEA to evaluate the economy of the nuclear hydrogen production system by estimating unit hydrogen production cost. In this paper, the LUHC (Levelized Unit Hydrogen Cost) is calculated by using HEEP for nuclear hydrogen production plant, which consists of 4 modules of 600 MWth VHTR coupled with SI process. The levelized unit hydrogen production cost(LUHC) was calculated by the HEEP software

  7. Calculation of LUEC using HEEP Software for Nuclear Hydrogen Production Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongho; Lee, Kiyoung; Kim, Minhwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    To achieve the hydrogen economy, it is very important to produce a massive amount of hydrogen in a clean, safe and efficient way. Nuclear production of hydrogen would allow massive production of hydrogen at economic prices while avoiding environments pollution by reducing the release of carbon dioxide. A Very High Temperature Reactor (VHTR) is considered as an efficient reactor to couple with the thermo-chemical Sulfur Iodine (SI) cycle to achieve the hydrogen economy. HEEP(Hydrogen Economy Evaluation Program) is one of the software tools developed by IAEA to evaluate the economy of the nuclear hydrogen production system by estimating unit hydrogen production cost. In this paper, the LUHC (Levelized Unit Hydrogen Cost) is calculated by using HEEP for nuclear hydrogen production plant, which consists of 4 modules of 600 MWth VHTR coupled with SI process. The levelized unit hydrogen production cost(LUHC) was calculated by the HEEP software.

  8. Catalytic asymmetric synthesis of a tertiary benzylic carbon center via phenol-directed alkene hydrogenation.

    Science.gov (United States)

    Caille, Seb; Crockett, Rich; Ranganathan, Krishnakumar; Wang, Xiang; Woo, Jacqueline C S; Walker, Shawn D

    2011-07-01

    An expeditious synthetic approach to chiral phenol 1, a key building block in the preparation of a series of drug candidates, is reported. The strategy includes a cost-effective and readily scalable route to cyclopentanone 3 from isobutyronitrile (10). The sterically hindered and enolizable ketone 3 was subsequently employed in a challenging Grignard addition mediated by LaCl(3)·2LiCl. A novel preparation of the lanthanide reagent required for this transformation is described. To complete the process, a highly enantioselective hydrogenation step afforded the target (1). The importance of the phenol group to the success of this asymmetric transformation is discussed. PMID:21630712

  9. Preparation and catalytic performance of monolayer-dispersed Pd/Ni bimetallic catalysts for hydrogenation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Pd/Ni bimetallic catalysts were prepared by replacement reactions,characterized by X-ray diffraction,CO chemisorption and H2 temperature-programmed desorption,and evaluated for hydrogenation of cyclohexene,styrene and acetone.The results show that Pd atoms are monolayer-dispersed on the Ni surface in these Pd/Ni catalysts.Consequently,Pd/Ni catalysts are much more active than Pd/Ni and Pd/γ-Al2O3 with the same Pd loading prepared by the conventional impregnation method.

  10. Production of hydrogen and sulfur from hydrogen sulfide assisted by nonthermal plasma

    International Nuclear Information System (INIS)

    Highlights: ► Hydrogen from direct decomposition of H2S by NTP method has been developed. ► Influence of various parameters has been studied. ► H2S conversion was efficient at higher residence time and lower concentrations. ► By optimizing residence time, it is possible to achieve H2 production at 160 kJ/mol. -- Abstract: Hydrogen production by nonthermal plasma (NTP) assisted direct decomposition of hydrogen sulfide was studied in a dielectric barrier discharge (DBD) reactor operated under ambient conditions. It may be concluded that NTP is effective in direct decomposition of H2S into H2 and S. Changing ground electrode material from silver paste to either copper wire or aluminium foil only increased the energy demand, but did not show any significant improvement in conversion. Influence of various parameters like ground electrode, discharge gap, residence time and H2S concentration were studied to achieve hydrogen production under energetically feasible conditions. It has been observed that H2S conversion into H2 and S may be efficient at high residence time and low concentrations. By optimizing the reaction conditions, H2 production may be produced at 160 kJ/mol (∼1.6 eV/H2) that is less than the energy demand in steam methane reforming (354 kJ/mol H2 or 3.7 eV/H2).

  11. Experimental study of hydrogen production by direct decomposition of water

    Science.gov (United States)

    Bilgen, E.; Galindo, J.; Baykara, S. Z.

    The hydrogen production by direct decomposition of water in a solar furnace is studied. The set-up is a horizontal axis system consisting of two 1.0 kW parabolic concentrators, both powered by a single heliostat. A temperature of 3000 K is possible. The water is fed to the reactor installed at the focal space of the concentrator, and the steam is decomposed at about 2500 K. The reactor consisted of a cylindrical cavity type refractory receiver covered with a silica cupola. The steam was introduced at a known rate into the cavity and the product gases were quenched. After the condensation of steam, hydrogen and oxygen were collected in a reservoir. Results indicate that with an optimized system, it is possible to produce hydrogen at about 70 percent rate of the theoretical value at the temperature level studied.

  12. Hydrogen production from agricultural waste by dark fermentation: A review

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xin Mei; Trably, Eric; Latrille, Eric; Carrere, Helene; Steyer, Jean-Philippe [INRA, UR050, Laboratoire de Biotechnologie de l' Environnement, F-11100 Narbonne (France)

    2010-10-15

    The degradation of the natural environment and the energy crisis are two vital issues for sustainable development worldwide. Hydrogen is considered as one of the most promising candidates as a substitute for fossil fuels. In this context, biological processes are considered as the most environmentally friendly alternatives for satisfying future hydrogen demands. In particular, biohydrogen production from agricultural waste is very advantageous since agri-wastes are abundant, cheap, renewable and highly biodegradable. Considering that such wastes are complex substrates and can be degraded biologically by complex microbial ecosystems, the present paper focuses on dark fermentation as a key technology for producing hydrogen from crop residues, livestock waste and food waste. In this review, recent findings on biohydrogen production from agricultural wastes by dark fermentation are reported. Key operational parameters such as pH, partial pressure, temperature and microbial actors are discussed to facilitate further research in this domain. (author)

  13. Process for the production of hydrogen/deuterium-containing gas

    International Nuclear Information System (INIS)

    A process for the production of hydrogen/deuterium-containing gas is described in which the enriched condensate obtained from the production of a hydrogen/deuterium-containing gas mixture is collected and subjected to a direct exchange of isotopes with the feedsteam admitted to the process. Such condensate can be brought into direct exchange of isotopes with the gas water vapor mixture within the process, viz. ahead of the CO conversion section. The exchange of isotopes may be performed according to the counter-current principle. If it is intended to maintain in the hydrogen/deuterium-containing gas a certain definite content of water vapor whose phase condition is superior to the condition achieved when using normal cooling water, this gas, at least 0.6 kg/m3 of gas, is subjected to an exchange of isotopes with the water fed additionally into the process

  14. Nuclear driven water decomposition plant for hydrogen production

    Science.gov (United States)

    Parker, G. H.; Brecher, L. E.; Farbman, G. H.

    1976-01-01

    The conceptual design of a hydrogen production plant using a very-high-temperature nuclear reactor (VHTR) to energize a hybrid electrolytic-thermochemical system for water decomposition has been prepared. A graphite-moderated helium-cooled VHTR is used to produce 1850 F gas for electric power generation and 1600 F process heat for the water-decomposition process which uses sulfur compounds and promises performance superior to normal water electrolysis or other published thermochemical processes. The combined cycle operates at an overall thermal efficiency in excess of 45%, and the overall economics of hydrogen production by this plant have been evaluated predicated on a consistent set of economic ground rules. The conceptual design and evaluation efforts have indicated that development of this type of nuclear-driven water-decomposition plant will permit large-scale economic generation of hydrogen in the 1990s.

  15. Catalytic hydro desulphurization study of heavy petroleum residue through in situ generated hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Shakirullah, Mohammad; Ahmad, Imtiaz; Ishaq, Mohammad; Ahmad, Waqas [Institute of Chemical Sciences, N.W.F.P., University of Peshawar, 25120 Peshawar (Pakistan)

    2010-05-15

    Hydrodesulphurization of heavy residue was carried out using various catalysts in the presence of co-reactants as the internal sources of hydrogen. Reactions were carried out in a micro autoclave at 320 C and 10 kg f/cm{sup 2} pressure inert atmosphere of N{sub 2} for 3 h reaction time. Tetralin, propane, methanol, ethylene glycol and formic acid were separately used as co-reactants as hydrogen donors. Among the solvents studied, methanol gave the highest hydrodesulphurization yield (52%). The reaction was then carried out in the presence of various catalysts to view the influence of each individual catalyst on the desulphurization yield under the same conditions of pressure and temperature. The catalysts used were Mo-Montmorillonite, Co-Montmorillonite, nickel oxide (NiO), cadmium oxide (CdO), Zn-ZSM5, kaolin and montmorillonite clays. The results show that all the catalysts exhibited desulphurization activity. In case of Mo-Montmorillonite and Co-Montmorillonite charges, the desulfurization yields of 63% and 46% were obtained, respectively. NiO, CdO, Zn-ZSM5, kaolin and montmorillonite clays gave desulphurization yields of 54%, 50%, 56%, 20% and 36%, respectively. The desulphurization activities of Mo-Montmorillonite and Co-Montmorillonite were compared with other catalysts used. The results show that Mo-Montmorillonite gave the highest hydrodesulphurization yield. FTIR studies also confirmed the hydrodesulphurization efficiency of the Mo-Montmorillonite. (author)

  16. Sorption enhanced reaction process (SERP) for production of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Sircar, S.; Anand, M.; Carvill, B. [Air Products and Chemicals, Inc., Allentown, PA (United States)] [and others

    1995-09-01

    Sorption Enhanced Reaction (SER) is a novel process that is being developed for the production of lower cost hydrogen by steam-methane reforming (SMR). In this process, the reaction of methane with steam is carried out in the presence of an admixture of a catalyst and a selective adsorbent for carbon dioxide. The consequences of SER are: (1) reformation reaction at a significantly lower temperature (300-500{degrees}C) than conventional SMR (800-1100{degrees}C), while achieving the same conversion of methane to hydrogen, (2) the product hydrogen is obtained at reactor pressure (200-400 psig) and at 99+% purity directly from the reactor (compared to only 70-75% H{sub 2} from conventional SMR reactor), (3) downstream hydrogen purification step is either eliminated or significantly reduced in size. The early focus of the program will be on the identification of an adsorbent/chemisorbent for CO{sub 2} and on the demonstration of the SER concept for SMR in our state-of-the-art bench scale process. In the latter stages, a pilot plant will be built to scale-up the technology and to develop engineering data. The program has just been initiated and no significant results for SMR will be reported. However, results demonstrating the basic principles and process schemes of SER technology will be presented for reverse water gas shift reaction as the model reaction. If successful, this technology will be commercialized by Air Products and Chemicals, Inc. (APCI) and used in its existing hydrogen business. APCI is the world leader in merchant hydrogen production for a wide range of industrial applications.

  17. Bio-hydrogen production from renewable organic wastes

    Energy Technology Data Exchange (ETDEWEB)

    Shihwu Sung

    2004-04-30

    Methane fermentation has been in practice over a century for the stabilization of high strength organic waste/wastewater. Although methanogenesis is a well established process and methane--the end-product of methanogenesis is a useful energy source; it is a low value end product with relatively less energy content (about 56 kJ energy/g CH{sub 4}). Besides, methane and its combustion by-product are powerful greenhouse gases, and responsible for global climate change. So there is a pressing need to explore alternative environmental technologies that not only stabilize the waste/wastewater but also generate benign high value end products. From this perspective, anaerobic bioconversion of organic wastes to hydrogen gas is an attractive option that achieves both goals. From energy security stand point, generation of hydrogen energy from renewable organic waste/wastewater could substitute non-renewable fossil fuels, over two-third of which is imported from politically unstable countries. Thus, biological hydrogen production from renewable organic waste through dark fermentation represents a critically important area of bioenergy production. This study evaluated both process engineering and microbial physiology of biohydrogen production.

  18. Solar production of catalytic filamentous carbon by thermal decomposition of hydrocarbons and carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Kirillov, V.A.; Kuvshinov, G.G.; Mogilnykh, Yu.I. [Boreskov Institute of Catalysis, Novosibirsk (Russian Federation); Reller, A. [University of Hamburg (Germany); Steinfeld, A.; Weidenkaff, A.; Meier, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Concentrated solar radiation was used as the clean source of process heat for the production of Catalytic Filamentous Carbon (CFC) by thermal decomposition of gaseous hydrocarbons and by CO disproportionation in the presence of small metal catalyst particles. Depending on the catalyst, two different types of CFC, namely nano tubes and nano fibers, were obtained in solar experiments at the PSI solar furnace. (author) 2 figs., 1 tab., 7 refs.

  19. Dimethyl carbonate as potential reactant in non-catalytic biodiesel production by supercritical method

    OpenAIRE

    Ilham, Zul; Saka, Shiro

    2009-01-01

    In this study, the non-catalytic supercritical method has been studied in utilizing dimethyl carbonate. It was demonstrated that, the supercritical dimethyl carbonate process without any catalysts applied, converted triglycerides to fatty acid methyl esters with glycerol carbonate and citramalic acid as by-products, while free fatty acids were converted to fatty acid methyl esters with glyoxal. After 12 min of reaction at 350 °C/20 MPa, rapeseed oil treated with supercritical dimethyl carbona...

  20. Fermentative hydrogen production from pretreated biomass: A comparative study

    NARCIS (Netherlands)

    Panagiotopoulos, I.A.; Bakker, R.R.; Budde, M.A.W.; Vrije, de G.J.; Claassen, P.A.M.; Koukios, E.G.

    2009-01-01

    The aim of this work was to evaluate the potential of employing biomass resources from different origin as feedstocks for fermentative hydrogen production. Mild-acid pretreated and hydrolysed barley straw (BS) and corn stalk (CS), hydrolysed barley grains (BG) and corn grains (CG), and sugar beet ex