Biohythane as an energy feedstock for solid oxide fuel cells

Abstract

Biogas (60%-CH4, 40%- CO2) is a potential source of renewable energy when used as energy feedstock for solid oxide fuel cells (SOFC), but releases biogenic CO2 emissions. Hybrid SOFC performance can be affected by fuel composition and reformer performance. Biohythane (58%-CH4, 35%-CO2 and 7% H2) can be a better alternative providing balance between energy and biogenic emissions. Biohythane performance is studied for a 120 kW SOFC stack using ASPEN process model and compared with other feed stocks. This work is the first to study and report on the application of biohythane in SOFC systems. Biohythane was found to produce less biogenic CO2 emissions and 6% less CO at the reformer than biogas. Comparisons show that biohythane provides better efficiencies in hybrid SOFC systems. Sensitivity studies recommends operation of stack with biohythane at Steam to Carbon Ratio (STCR) = 2.0, i = 200 mA cm−2 and UF = 0.85 respectively.