生物气及其电池尾气SOFC放电性能研究

Investigation of Discharge Performance of SOFC Using Biogas and Its Off-gas

为探究以不同浓度生物气为燃料的固体氧化物燃料电池(SOFC)发电性能及该类电池尾气的再发电价值,通过模拟含不同比例甲烷和二氧化碳的生物气,在750℃下对气路串联Ni/YSZ阳极支撑SOFC进行放电性能测试和气体特性分析。放电结果显示燃料气经第一级SOFC利用后通入第二级SOFC,同氢气经过两级SOFC相比,不同浓度下生物气均获得了较高的功率密度,且短时间恒流时,两级电池均能稳定运行;两级电池均以566 m A?cm-2电流密度恒流放电时的气体分析表明,当CO2/CH4为2时,电池内甲烷的干重整率最高。研究结果表明两级SOFC使用生物气及其电池尾气发电是可行的,可为以生物气为燃料SOFC电堆气路设计提供依据。

To investigate the discharge performance of Ni-YSZ anode solid oxide fuel cell using various biogas and evaluate the valve of reusing its off-gas, electrochemical performance and gas properties were studied when two SOFC operated in tandem using diverse ratio of CH4/CO2 at 750 ℃. Compared with the cell performance using H2, two SOFC both operated at high power density with the first stage SOFC using various CH4/CO2 biogas and the second stage using the off-gas of the first stage. Both of two SOFC worked mostly steadily at constant current density for short time with little carbon deposition. The analysis of the gas properties at 566 mA-cm-2 indicated that the dry reforming rate was the highest when the ratio of CH4/CO2 was 2. The research results show that power generation of SOFC using biogas and its off-gas is feasible. This research can be useful for designing gas circuit of SOFC piles using biogas.