Enhanced conversion efficiency and coking resistance of solid oxide fuel cells with vertical-microchannel anode fueled in CO2 assisted low-concentration coal-bed methane

Abstract

Clean and efficient utilization of the abundant low concentration coal-bed methane (LC-CBM) via solid oxide fuel cells (SOFCs) is highly attractive for saving energy and mitigate the emission of greenhouse gases. However, it still remains a great challenge because of the low conversion efficiency and carbon deposition. Herein, an improvement strategy is proposed via incorporating dry reforming reaction of CO2 assisted LC-CBM. By introducing CO2 in LC-CBM, the methane conversion improves significantly. A maximum methane conversion is achieved by incorporating 5 %CO2 and the value is increased from 31.69% to 50.03%. Meanwhile, a high CO2 conversion of 74.58% is also achieved. The maximum power density of the single cell with vertical-microchannel anode fueled with 5 %CO2 in LC-CBM is 1321.5 mW cm−2 at 800 °C, which is a bit lower than that without CO2 participation. This is probably ascribed to the open circuit voltage decrease caused by the increased partial pressure of oxygen at anode. The coking tolerance of the single cell with CO2 participation can be improved owing to the high conversion efficiency, leading to a stable power output performance. CO2 assisted LC-CBM for SOFCs provides a potential solution for the efficient conversion of the low calorific value fuels.