Performance Study on Intermediate Temperature Solid Oxide Fuel Cell and Gas Turbine Hybrid System Fueled With Biomass Gas

Abstract

In this work, the detailed model of intermediate temperature solid oxide fuel cell (IT-SOFC) and gas turbine (GT) hybrid system with biomass gas (wood chip gas) as fuel was built, with the consideration of fuel cell potential loss such as polarization loss and heat loss. Detailed performance of key component such as reformer, fuel cell and gas turbine of the hybrid system was studied under different biomass gas fuel compositions and steam/carbon ([S]/[C]) ratios. The results show that the hybrid system can reach the efficiency of 59.24% under the designed working condition. The biomass gas from different sources and processes usually have varied fuel concentrations, especially for methane (CH4), hydrogen (H2), carbon monoxide (CO) and water (H2O), which could significantly affect the performance of hybrid system. Results show that the change of H2 proportion has the most significant influence to system output power, CO and CH4 have similar influence trend. System electrical efficiency increases slightly with the change of H2 proportion while decreasing significantly with the increase of CO and CH4 proportion. The increasing composition of CH4, H2 and CO in biomass gas fuel benefits the output power of hybrid system, but results in the higher risk of overheat as well, which might cause safety problems. The composition of water in biomass gas affects the [S]/[C] ratio of system, and results show that maintaining the [S]/[C] ratio at a certain level can guarantee the temperature of key components in the hybrid system below the limits, which can satisfy the safety standards. The results show this technology has a good application prospect. (CSPE)