Study of the role of chemical support and structured carrier on the CO2 methanation reaction

Abstract

Power-to-Gas (PtG) technology is particularly interesting because it is based on a mature technology such as the methanation process, based on the established Sabatier reaction. The industrial applicability of such technology is severely limited by the huge exothermicity of the process, that affects the catalyst stability. The aim of this work was to investigate the effect of the chemical and physical support for Sabatier reaction. Nickel based samples were prepared, by deposing the active metal on alumina (as a commercial reference), ceria and a cerium-zirconium mixed oxide supports. The catalytic activity tests confirmed that rare heart oxides supports strongly improved the catalytic performances, both in terms of CO2 conversion and selectivity to CH4, probably due to the basic nature of such supports. The CeZr-based formulation was then deposited on structured carriers with highly thermal conductivity, like a silicon carbide monolith (SiC) and an aluminium foam. Experimental achievements highlighted the effect of conductive carriers on the temperature profile along the reactor volume. SiC monolith and aluminium foam are able to guarantee a flattest thermal profile than the powder, thus in one and ensuring a higher conversion of carbon dioxide, in the other hand strongly suppressing side-reaction contribution, therefore maximising the selectivity to methane.