Effect of pollutants on biogas steam reforming

Biogas produced by biomasses anaerobic digestion is mainly composed by CH4 and CO2, although pollutants, as H2S siloxanes and hydrocarbons compounds, could be present depending on the nature of the biomass, process conditions and type of digester used. Biogas steam reforming experiments were carried out, at 1073 K and steam methane ratio=2 mol/mol, in order to investigate on the effect of biogas pollutants on the performances of a Nichel catalyst. Different biogas streams were used. In particular, both a stream exclusively composed of CH4 and CO2 (CH4/CO2= 55/45 vol.%) and a gas mixture of CH4/CO2 and pollutants were used. Resulted showed a stable Ni performance when a "clean" biogas stream was reformed; On the contrary, the simultaneously presence of two poisoning in to the inlet gas stream negatively affected catalytic performances promoting also the coke formation.