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Copyright of Acta Scientiarum: Technology is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Scientiarum: Technology is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ethanol steam reforming for hydrogen production was evaluated using Cu–Ni/Nb x O y catalyst prepared by ion exchange (IE), wet impregnation (WI) and co-precipitation (CP). The catalysts were characterized by textural analysis, chemisorption of H 2 and N 2 O for metallic area determination, XDR (calcined and in situ reduced samples), TPR-H 2 , TPD-NH 3 , MET/EDX e TPO-O 2 . Differences in crystal structure and metal-support interaction have altered the reducibility of the catalysts, besides metal surface area and crystallite size of Cu and Ni. The catalytic tests, using ethanol:water molar ratio of 1:10, temperature of 450 and 500 °C, demonstrated high H 2 yield and stability, except for the IE catalyst at 500 °C, which favored the ethylene formation by ethanol dehydration. The main route for H 2 obtainment in all cases was ethanol decomposition. The temperature increasing up to 500 °C favored the by-product CH 4 reforming. The weakest metal-support interaction on WI catalyst provided the fully reduced metal phase, however, support characteristics achieved by this preparation method led to the filamentous coke formation. TEM images showed that different crystalline structures of the support modified the mechanism of the reaction and consequently the type of coke deposited on the surface. The CP catalyst showed low coke deposition and no metal sintering, stoichiometric H 2 /CO 2 ratio, less than 5% of CH 4 , and no CO, which makes it the best candidate for hydrogen production by ethanol steam reforming. [ABSTRACT FROM AUTHOR]

New data were obtained for production of H 2 and reduction of total organic carbon (TOC) by gasification of lactose in supercritical water with(out) the presence of catalysts (NaOH, KOH and Na 2 CO 3 ) in a continuous Inconel 625 flow reactor. The gasification reactions were carried out at 550–700 °C, 22.5 MPa, lactose concentrations in the range of 0.5–2.5 wt%, feed flow rates of 5 and 7 g min −1 and a total reaction time of 30 min. The optimum condition for the production of H 2 yielded approximately 4.5 mol H 2 /mol lactose with a TOC reduction of ∼95%. In addition, supercritical gasification of whey was carried out using the same operating conditions as the lactose system. A reduction of 92% on the TOC and 0.45 molar fraction of H 2 production was achieved, similar to the gasification of lactose at a concentration of 0.5 wt%. [ABSTRACT FROM AUTHOR]

Abstract: In this work a thermodynamic analysis of the autothermal reforming (ATR) of methane was performed. Equilibrium calculations employing entropy maximization were performed in a wide range of oxygen to methane mole ratio (O/M), steam to methane ratio (S/M), inlet temperature (IT), and system pressure (P). The main calculated parameters were hydrogen yield, carbon monoxide formation, methane conversion, coke formation, and equilibrium temperature. Further, the optimum operating oxygen to methane feed ratio that maximizes hydrogen production, at P = 1 bar, has been calculated. The nonlinear programming problem applied to the simultaneous chemical and phase equilibrium calculation was implemented in GAMS®, using CONOPT2 solver. The maximum amount of hydrogen obtained was in the order of 3 moles of hydrogen per mole of fed methane at IT = 1000 °C, P = 1 bar, S/M = 5, and O/M = 0.18. Experimental literature data are in good agreement with calculation results obtained through proposed methodology. [Copyright &y& Elsevier]

Abstract: The ethanol oxidative reforming reaction was performed with Ni–Cu catalysts on different supports. The results indicated that Ni–Cu/Nb2O5 and Ni–Cu/ZnO were the most appropriate catalysts for the reaction regarding activity, stability, and selectivity for hydrogen production. Ni–Cu/Nb2O5 catalysts have strong acidity (at 600 °C), while ZnO has very low acidity. Ni–Cu/Ce0.6Zr0.4O2 catalysts, which only have weak acidity (at 250 °C), presented poor stability and hydrogen selectivity. This shows that acidity has no influence on hydrogen production. [Copyright &y& Elsevier]

Abstract: Ni–Cu catalysts supported on different materials were tested in ethanol steam reforming reaction for hydrogen production. These catalysts were evaluated at reaction temperature of 400°C under atmospheric pressure. The reagents, with a water/ethanol molar ratio equal to 10, were fed at 70dm3/(hgcat) (after vaporization). Analysis of the ethanol conversion, as well as evaluation and quantification of the reaction products, indicated the catalyst 10% Ni–1% Cu/Ce0.6Zr0.4O2 as the most appropriate for the ethanol steam reforming under investigated reaction conditions, among the studied catalysts. During 8h of reaction this catalyst presented an average ethanol conversion of 43%, producing a high amount of H2 by steam reforming and by ethanol decomposition and dehydrogenation parallel reactions. Steam reforming, among the observed reactions, was quantified by the presence of carbon dioxide. About 60% of the hydrogen was produced from ethanol steam reforming and 40% from parallel reactions. [Copyright &y& Elsevier]