Conversion of biogas to synthesis gas over Ni/CeO2-Sm2O3catalysts

MARÍA GENOVEVA ZIMICZ; B. REZNIK; S.A. LARRONDO.

Acapulco

Congreso; IInternational-Mexican Congress on Chemical Reaction Engineering; 2014

Instituto Mexicano del Petróleo

In recent years, the worldwide concern about global warming and its consequences on human like has guided much of the research work to the development of renewable energy sources and sustainable processes. In particular, obtaining fuels from biomass has aroused great interest due to the possibility of closing the carbon cycle in the production of energy and the manufacturing of chemical products [1]. The conversion of the biogas into Syngas (mixtures of H2 and CO) constitutes a possible way of revalorization of residential, industrial and agricultural wastes. Biogas consists mainly of methane (CH4) and carbon dioxide (CO2), so the reaction to be carried out is the dry reforming of methane: CO2 (g) + CH4 (g)  2CO (g) + 2H2 (g) (1). Various catalytic systems have been studied for this reaction, being those based on Rh which showed better performance [2]. However, the developing of Ni-based catalytic systems would reduce the costs of this technology [3,4]. Nickel is an active dehydrogenating catalysts but it is necessary to support it on a system with the capacity to produce the rapid oxidation of the methane dehydrogenated fragments in order to prevent the formation of carbonaceous deposits. Additionally, the support must have basic sites to produce the dissociative adsorption of CO2 [5]. It is well-known that ceria-based oxides have the capability to easily exchange oxygen with the surrounding atmosphere (Oxygen Storage Capacity, OSC). The partial replacement of Ce4+ by aliovalent cations, like Sm3+, increases the OSC and the number of oxygen vacancies and their mobility being these vacancies active sites for dissociative adsorption of CO2. For these reasons, the study of the performance of Ni/CeO2-Sm2O3 catalysts in the conversion of biogas to syngas is proposed.