Ethanol reforming

Advances in catalysis and processes for hydrogen production from ethanol reforming... 

Ethanol and methane steam reforming reactions were studied assuming that the exit composition of the ethanol reformer depends on the steam reforming of methane. The competition for the same active site for ethanol and methane reforming maximizes the H2 and C02 production and minimizes the CO formation Catalysts were prepared by incipient wet impregnation. 20 wt% Ni supported on ZnO exhibited better performance compared to that supported on La203, MgO and A1203... 

Could be the activation energy for the decomposition of ethanol to CH4, CO and H2 rather than ethanol reforming into H2-rich syngas. 

Alloying of the active metal such as Ni with Cu has also been known to suppress the carbon deposition on the catalyst surface and this improved the stability of the Ni-Cu/Si02 catalyst during ethanol reforming.34... 

Most of the work on ethanol reforming to date focused mainly on catalyst development, optimization of reaction operations and thermodynamic analyses. However, detailed kinetic studies, which are very useful to understand the activity at the molecular level and to build a suitable catalytic reactor on an industrial scale for the reforming of ethanol need to be pursued. 

Cobalt-based catalysts are effective in the ethanol reformation to hydrogen. Many oxides have been used to prepare supported cobalt catalysts of low cobalt content (circa 1 wt%) by impregnation from a solution of Co2(CO)8 catalysts were used in the ethanol reformation as prepared [156]. The performance of the catalysts in the steam reforming of ethanol was related with the presence, under reaction conditions, of metallic (ferromagnetic) cobalt particles and oxidized cobalt species. An easy exchange between small metallic cobalt particles and oxidized cobalt species was found. Comparison of Co/ZnO catalysts prepared from Co2(CO)8 or from nitrate precursor indicated that the catalyst prepared from the carbonyl precursor was highly stable and more selective for the production of CO-free hydrogen... 

Fuel Cells for Defence Application. This R D Fuel Cell Program for defence applications has the main objective of analyzing current fuel cells and reformers and promoting their integration in mobile and stationary defence applications. Work will include and diesel and ethanol reformers. 

The removal of low concentrations of carbon monoxide from the pre-cleaned reformate of hydrocarbon and ethanol reformers is commonly performed by oxidation with air. Owing to the lower carbon monoxide concentration achieved by the low temperatures of methanol reforming, in this case the reformate goes directly to the preferential CO oxidation (PrOx) ... 

As discussed above in the reforming of hydrocarbon fuels, H2 can be produced from alcohol fuels by at least three major catalytic processes, namely steam reforming, partial oxidation and ATR or oxidative steam reforming. The chemistry, thermodynamics, and recent developments in catalysis of methanol and ethanol reforming with steam for H2 production will be discussed in this section. 

Recently, Comas et al.219 performed the thermodynamic analysis of the SRE reaction in the presence of CaO as a C02 sorbent. The equilibrium calculations indicate that the presence of CaO in the ethanol steam reforming reactor enhances the H2 yield while reducing the CO concentrations in the outlet of the reformer. Furthermore, the temperature range at which maximum H2 yield could be obtained also shifts from above 700 °C for the conventional steam reforming reaction without CaO to below 700 °C, typically around 500 °C in the presence of CaO. It appears that the presence of CaO along with ethanol reforming catalyst shift the WGS equilibrium in the forward direction and converts more CO into C02 that will be simultaneously removed by CaO by adsorption. 

Carbon formation and catalyst deactivation have also been observed in the SRE. Approaches similar to those discussed above for the steam reforming of hydrocarbons are also employed to suppress the carbon formation in ethanol reforming as well.1 7... 

Velu, S. and Song, C. Advances in catalysis and processes for hydrogen production from ethanol reforming. Catalysis, 2007, 20, 65. 

Barroso, M.N., Gomez, M.F., Arrua, L.A., and Abello, M.C. Hydrogen production by ethanol reforming over NiZnAl catalysts. Applied Catalysis. A, General, 2006, 304, 116. 

Diagne, C., Idriss, H., Pearson, K., Gomez-Garcia, M.A., and Kiennemann, A. Efficient hydrogen production by ethanol reforming over Rh catalysts. Effect of addition of Zr on Ce02 for the oxidation of CO to C02. Comptes Rendus Chimie, 2004, 7, 617. 

Casanovas, A., Llorca, I., Homs, N., Fierro, J.L.G., and Ramirez de la Piscina, P Ethanol reforming processes over ZnO-supported palladium catalysts Effect of alloy formation. Journal of Molecular Catalysis A Chemical, 2006, 250 (1-2), 44. 

Klouz, V., Fierro, V., Denton, P., Katz, H., Lisse, J.P., Bouvot-Mauduit, S., and Mirodatos, C. Ethanol reforming for hydrogen production in a hybrid electric vehicle Process optimisation. Journal of Power Sources, 2002, 105 (1), 26. 

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