Combined methane reforming by carbon dioxide and steam in proton conducting solid oxide fuel cells for syngas/power co-generation

Methane and carbon dioxide mixture can be used as the fuel in a proton conducting solid oxide fuel cell (SOFC)for power/syngas co-generation and greenhouse gas reduction. However, carbon deposition and low conversion ratio are potential problems for this technology. Apart from using functional catalytic layer in the SOFC to enhance CH₄ dry reforming, adding H₂O into the fuel stream could facilitate the CH₄ conversion and enhance the co-generation performance of the SOFC. In this work, the effects of adding H₂O to the CO₂[sbnd]CH₄ fuel on the performance of a tubular proton conducting SOFC are studied numerically. Results show that the CH₄ conversion is improved from 0.830 to 0.898 after adding 20% H₂O to the anode. Meanwhile, the current density is increased from 2832 A m⁻² to 3064 A m⁻² at 0.7 V. Sensitivity studies indicate that the H₂:CO ratio can be effectively controlled by the amount of H₂O addition and the H₂ starvation can be alleviated, especially at high current density conditions.