Design and Evaluation of the Sorption Enhanced Steam Reforming and Solid Oxide Fuel Cell Integrated System with Anode Exhaust Gas Recirculation for Combined Heat and Power Generation

Abstract

Solid oxide fuel cell (SOFC) is an electrochemical device for power generation with high efficiency and low environmental impact. Due to a high-temperature operation of SOFC, useful heat can be recovered to enhance its system efficiency. Regarding the environmental concern, bio-oil, the renewable liquid fuel, can be applied to SOFC system. In this study, the SOFC integrated with a steam reforming of bio-oil is considered. A sorption enhanced reforming process is studied for the production of high purity hydrogen for SOFC, and the anode gas recirculation in the SOFC system is proposed for the system improvement. Modeling of such an integrated process is performed using Aspen Plus simulator. As heat and power are generated from the SOFC system, the effect of key design parameters; fuel utilization and recirculation ratio of the anode gas, on a heat- to-power ratio is analyzed. The system performance regarding to the electrical and thermal efficiencies is also evaluated. The results show that increasing the anode recirculation ratio increases the combined heat and power (CHP) performance, but increasing the fuel utilization decreases the thermal efficiency. It is also found that the appropriate range of heat-to-power ratio of the system varies from 0.24 to 0.89.