Analysis of biogas reforming process for molten carbonate fuel cells

The paper reports the main results of an investigation on biogas reforming process developed for an integration with high temperature fuel cells systems. Experimental activities have been developed to determine performances of a nickel catalyst in different biogas reforming conditions have been investigated. Attention has been addressed toward the effect of gasifier agents (CO2, H2O and O2) on outlet stream composition and carbon deposition on catalytic surface. Previously, the carbon formation rate in dry and steam reforming reactions apply to a biogas stream (CH4/CO2-60/40 vol%) has been evaluated using Aspen plus chemical processor simulator in order to define the operative conditions limit and to selected the best one. A mathematical model, based on experimental data, has been developed to compare the polarization curves of a MCFC mono-cell fed with three different syngas compositions obtained by biogas reforming section in order to find out the best operational conditions for the two integrated systems (MCFC/fuel processor). A parallel trend of the the polarization curves have been obtained due to the assumptions considered for the model developing, as: (i) inlet gas composition effects on ohmic and activation loses are negligible; (ii) diffusional losses are dependent by gas compositions; (iii) diffusional losses are negligible in the graphic sections characterized by low current density.