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Fe/CeO2 catalysts with different ferrum loading were prepared by solid state melting method. Ethanol decomposition on those catalysts at different temperature (600, 700, and 800°C) has been studied. To evaluate the catalytic performance in ethanol decomposition, gaseous and solid products produced from ethanol decomposition were collected and analyzed; H2 and multi-walled carbon nanotubes (MWCNTs) were obtained. In these experiments, ethanol decomposition on Fe (30 wt%)/CeO2 at 600°C showed the maximum H2 yield (the maximum H2 yield was 94%, which was higher than that of previous reports). In addition, other gaseous products include CH4 and CO were observed, but CO2 was not be detected. The content of H2, CO, and CH4 were 60 ~ 80%, 20 ~ 25%, and 0 ~ 10%, respectively. MWCNTs have formed in ethanol decomposition process, the quality and purity of MWCNTs increase with increasing temperature, and the material with the carbon-encapsulated metal structure was obtained. [ABSTRACT FROM AUTHOR]

This paper deals with an investigation of the reactivity of spinel type mixed oxide, i.e., NiMn 2 O 4 , in the chemical loop reforming of ethanol (CLRE) to CO and H 2 . The Ni ferrite showed a higher activity in CLRE, which was also confirmed by TPR experiments. During the first minutes of reaction, when the materials still acted as reactants while being reduced at the same time, the two oxides showed differences in regard to the nature of the products formed. During reduction, the structural evolution was monitored by means of several physical techniques, thus showing the formation of MnO and metallic species (Ni and Mn) as well. [ABSTRACT FROM AUTHOR]

SUMMARY Chemical-looping ethanol reforming with carbon dioxide capture is proposed. It combines chemical-looping reforming and carbon dioxide capture for pure hydrogen generation from ethanol with inherent separation of carbon dioxide. A thermal analysis of the process using NiO oxygen carrier is performed by simulating reactions using the Gibbs energy minimization method. The promising systems are investigated further with respect to temperature, NiO/C2H5OH molar ratio, CaO/C2H5OH molar ratio and pressure changes as well as possible carbon formation in the reformer. Favorable operation conditions in the presence of CaO are: pressures around 3 atm, reactor temperatures around 850 K, NiO/C2H5OH molar ratio = 3 and CaO/C2H5OH = 3. The H2 yield and thermal efficiency with CaO addition are higher than that without CaO addition, showing that the addition of a CO2 sorbent in the process increases the H2 production. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this work, the thermodynamic property of combined carbon dioxide and steam reforming of ethanol to generate hydrogen for fuel cells is studied. The effects of operating conditions such as pressure, temperature, and feed reactants ratio on the ethanol reforming process were analyzed by Gibbs free energy minimization method. The optimum conditions for hydrogen-rich gas production are identified: reaction temperatures between 1100 and 1200 K, carbon dioxide-to-ethanol molar ratio of 2, and steam-to-ethanol molar ratio of 3 at 1 atm. Under the optimal conditions, complete conversion of ethanol, 3.40–3.57 mol hydrogen/mol ethanol and 2.42–2.60 mol carbon monoxide/mol ethanol, could be achieved in the absence of coke formation. The combined carbon dioxide and steam reforming of ethanol is suitable for providing hydrogen-rich fuels for a solid oxide fuel cell. The coke-formed and coke-free regions are found, which are useful in guiding the search for suitable catalysts for the reaction. [ABSTRACT FROM PUBLISHER]

Abstract: Dry reforming of butanol for hydrogen production has been studied by Gibbs free energy minimization method. The calculation results showed that the formation of hydrogen and carbon monoxide was through a multi-step pathway via the dehydrogenation, dehydration, decomposition and carbon dioxide reforming of butanol. The optimum conditions for hydrogen production are identified: reaction temperatures between 1150 and 1200K and carbon dioxide-to-butanol molar ratios between 3.5 and 4.0 at 1atm. Under the above conditions, 100% conversion of butanol, 34.91–37.98% concentration of hydrogen and 57.34−57.87% concentration of carbon monoxide could be achieved in the absence of coke formation. The butanol dry reforming with carbon dioxide is suitable for providing fuels for Solid Oxide Fuel Cell (SOFC). The coke-formed and coke-free regions are found, which are useful in guiding the search for suitable catalysts for the reaction. [Copyright &y& Elsevier]

Abstract: Thermodynamic equilibrium for sorption enhanced steam reforming of butanol (SESRB) to hydrogen was investigated using Gibbs free energy minimization method. The optimal operation conditions for SESRB are at 800 K, the steam-to-butanol molar ratio of 10, the calcium oxide-to-butanol molar ratio of 8 and atmospheric pressure. Under the optimal conditions, complete conversion of butanol, 97.07% concentration of H2 and 0.05% concentration of CO2, and efficiency of 86.60% could be achieved and at which no coke tends to form. Under the same conditions in SRB, 58.18% concentration of H2, 21.62% concentration of CO2, and energy efficiency of 81.51% could be achieved. Butanol steam reforming with CO2 adsorption has the higher H2 content and efficiency, and lower CO2 content than that without adsorption under the same reaction conditions. In addition, reaction conditions for coke-free and coke-formed regions are also discussed in butanol steam reforming with or without CO2 separation. [Copyright &y& Elsevier]

Abstract: Thermodynamics of glycerol partial oxidation for hydrogen production has been studied by Gibbs free energy minimization method. The optimum conditions for hydrogen production are identified: reaction temperatures between 1000 and 1100K and oxygen-to-glycerol molar ratios of 0.4–0.6 at 1atm. Under the optimal conditions, complete conversion of glycerol, 78.93%–87.31% yield of hydrogen and 75.12%–87.97% yield of carbon monoxide could be achieved in the absence of carbon formation. The glycerol partial oxidation with O2 is suitable for providing hydrogen-rich fuels for Molten Carbonate Fuel Cell and Solid Oxide Fuel Cell. The carbon-formed and carbon-free regions are found, which are useful in guiding the search for suitable catalysts for the reaction. Inert gases have a positive effect on the hydrogen and carbon monoxide yields. [ABSTRACT FROM AUTHOR]

Abstract: Thermodynamic equilibrium for glycerol steam reforming to hydrogen with carbon dioxide capture was investigated using Gibbs free energy minimization method. Potential advantage of using CaO as CO2 adsorbent is to generate hydrogen-rich gas without a water gas shift (WGS) reactor for proton exchange membrane fuel cell (PEMFC) application. The optimal operation conditions are at 900 K, the water-to-glycerol molar ratio of 4, the CaO-to-glycerol molar ratio of 10 and atmospheric pressure. Under the optimal conditions, complete glycerol conversion and 96.80% H2 and 0.73% CO concentration could be achieved with no coke. In addition, reaction conditions for coke-free and coke-formed regions are also discussed in glycerol steam reforming with or without CO2 separation. Glycerol steam reforming with CO2 adsorption has the higher energy efficiency than that without adsorption under the same reaction conditions. [ABSTRACT FROM AUTHOR]

Abstract: Thermodynamics of ethanol reforming with carbon dioxide for hydrogen production has been studied by Gibbs free energy minimization method. The optimum conditions for hydrogen production are identified: reaction temperatures between 1200 and 1300K and carbon dioxide-to-ethanol molar ratios of 1.2–1.3 at 0.1MPa. Under the optimal conditions, complete conversion of ethanol, 94.75–94.86% yield of hydrogen and 96.77–97.04% yield of carbon monoxide can be achieved in the absence of carbon formation. The ethanol reforming with carbon dioxide is suitable for providing hydrogen-rich fuels for molten carbonate fuel cell and solid oxide fuel cell. The carbon-formed and carbon-free regions are found, which are useful in guiding the search for suitable catalysts for the reaction. Inert gases have a positive effect on the hydrogen and carbon monoxide yields. [Copyright &y& Elsevier]

Abstract: A metallic Ni catalyst has been prepared with nickel sponge and further promoted with YSZ (yttrium-stabilized zirconia) by an impregnation method. The catalysts are characterized by ICP, BET, SEM, XRD and H2-TPR, and then studied for the partial oxidation of methane to hydrogen. The influences of reaction temperature, CH4/O2 ratios and gas hourly space velocity on the reaction rate are investigated. The catalyst characterization results show that the YSZ-promoted metallic Ni catalysts have high specific surface area; there is more NiO phase in the YSZ-promoted catalysts than in the metallic Ni catalyst; a mutual diffusion of Ni2+ and Zr4+ ions might happen between the NiO and YSZ phases. The reaction results show that the YSZ promotion increases the CH4 conversion and the selectivities to H2 and CO. [Copyright &y& Elsevier]

In the present study, nickel-copper bimetallic catalysts were investigated for the steam reforming of bio-ethanol. A comparison was made to the 10% nickel and the different content of copper supported on γ-Al2O3 promoted by MgO. Experimental results showed that the 10Ni5Cu/MgO/γ-Al2O3 catalyst was superior to other catalysts, especially in terms of the hydrogen-to-carbon monoxide ratio. Influential factors, such as reaction temperature, water-to-ethanol molar ratio, and liquid hourly space velocity (LHSV), were investigated using the 10Ni5Cu/MgO/γ-Al2O3 catalyst. The conversions were always completed at temperatures above 400°C, regardless of the changes of the reaction conditions. However, the yield to hydrogen increased with the increase in temperature and H2O/C2H5OH molar ratio. The hydrogen yield up to 71% was reached under these conditions: 550°C, LHSV of 5.0 h-1, and H2O/C2H5OH ratio of 10 over the 10Ni5Cu/MgO/γ-Al2O3 catalyst. The effects of the influential factors on the side reactions and the distribution of by-products were also discussed. [ABSTRACT FROM AUTHOR]

Abstract: Thermodynamic equilibrium of ethanol partial oxidation has been studied by Gibbs free energy minimization method for hydrogen production in the range of oxygen-to-ethanol molar ratio from 0 to 3, reaction temperature from 500 to 1400K, pressure from 1 to 20atm and nitrogen-to-ethanol molar ratio from 0 to 100. The optimal operation conditions were obtained, which are 1070–1200K, oxygen-to-ethanol molar ratio of 0.6–0.8, and 1atm. Under the optimal conditions, complete conversion of ethanol, 86.28–94.98% yield of hydrogen and 34.69–38.64% concentration of carbon monoxide could be achieved and at which no coke tends to form. The hydrogen-rich fuel obtained is suitable for the use in Molten Carbonate Fuel Cell and Solid Oxide Fuel Cell. Higher pressures have a negative effect on the hydrogen yield. Inert gases have a negative effect on the hydrogen yield at low nitrogen-to-ethanol molar ratios (below 40), but further increasing the concentrations of the inert gases increases the hydrogen yield slightly. Coke tends to form at lower temperatures and lower oxygen-to-ethanol molar ratios. [Copyright &y& Elsevier]