Conversion of Simulated Biogas in a SOFC: The Effect of Organic Compounds

Abstract

Fuel from a gasifier contains a series of organic compounds, mainly in the range of C1-C16. CH4 is known to be converted by the SOFC, far less is known about the conversion of higher hydrocarbons and the effect on the degradation of the SOFC. In the EU project Green-Fuel-Cell , a SOFC stack will be connected to a biomass gasifier. For the determination of the allowable concentration of higher hydrocarbons for the stack test, single cell tests with simulated gas from a gasifier containing various hydrocarbons were performed. From these single cell tests it was concluded that C2H2, C2H4 and C7H8 were completely converted without degradation of the performance of the SOFC. The addition of C10H8, C14H10 and C16H10 resulted in a strong cell voltage degradation, which appeared to be due to the blocking of the reforming of CH4. The electrochemical conversion of H2 was hardly effected by these organic compounds

Conversion of tars on solid oxide fuel cell anodes and its impact on voltages and current densities

“…Synthetic hydrocarbon‐syngas mixtures were investigated by Dekker et al. in 2007 . The gas composition was set to 16% CO, 14% CO 2 , 14% H 2 , 13% H 2 O, 4% CH 4 and 36% N 2 .…”

“…However, toluene, ethylene, and acetylene contributed to the cells performance, naphthalene and pyrene caused a rapid power loss. The researcher attributed the adverse behavior of those two components to an inhibiting character regarding other hydrocarbon reforming . Methane contains – even in low concentrations that is 4% – a large proportion of the fuels heating value.…”

“…character regarding other hydrocarbon reforming [48]. Methane contains -even in low concentrations that is 4% -a large proportion of the fuels heating value.…”

“…Methane contains – even in low concentrations that is 4% – a large proportion of the fuels heating value. In its unreformed state methane is relatively unavailable for the electrochemical conversion and fuel utilization can readily rise into ranges where safe operation of the cell cannot longer sustain .…”

Experimental Investigation of Naphthalene Induced Degradation of Reversible Solid Oxide Cells Operated on Bio-Syngas

“…The utilization of model tars tends to overestimate the influence of real tars 8 and is, therefore, a conservative approach commonly used. The most prominent utilized model tars are naphthalene, [9][10][11][12][13][14][15][16][17][18] toluene, 8,10-12,15,17-32 phenol 14,33 and benzene. 4,10,11,26,27,34,35 In comparative studies, naphthalene shows the lowest tendency to coke formation 11 and the highest impact on the catalytic methane reforming 12 as well as on the electrochemical performance.…”