Effects of low hydrocarbons on the solid oxide fuel cell anode

Abstract

In this work, the effects of ethylene on the solid oxide fuel cell (SOFC) anode were investigated both for an SOFC single cell and an SOFC stack. Two fuels were used to observe the effects that low hydrocarbons (over C1-hydrocarbons) in the reformate gas stream have on the SOFC anode. Methane or ethylene was supplied to the electrolyte-supported SOFC anode. Using ethylene as a fuel, catastrophic degradation of SOFC performance was observed due to ethylene-induced carbon deposition onto the SOFC anode. Thus, a new methodology, termed "post-reforming," is introduced for the removal of low hydrocarbons (over C1-hydrocarbons) from the reformate gas stream. The CGO-Ru catalyst was selected as the post-reforming catalyst because of its high selectivity for removing low hydrocarbons (over C1-hydrocarbons) and for its long-term stability. The diesel reformer and post-reformer were continuously operated for similar to 250 h in coupled-operation mode. The reforming performance was not degraded, and low hydrocarbons (over C1-hydrocarbons) in the diesel reformate were completely removed.