Performance analysis of solid oxide fuel cell integrated with ethanol reforming process

Abstract

This study presents a performance analysis of solid oxide fuel cell (SOFC) integrated with different ethanol reforming processes by considering both the electrical and the thermal performances. Thermodynamic analysis of the SOFC system operated under steady state condition was performed using a flowsheet simulator. Detailed electrochemical model taking into account all voltage losses (i.e., activation, concentration and ohmic losses) was considered. Three different ethanol reforming processes, i.e., steam reforming (SR), partial oxidation (POX) and autothermal reforming (ATR) were studied for hydrogen production. The simulation results showed that increases in reformer and fuel cell operating temperatures can improve the electrical performance of the SOFC system, whereas steam to ethanol ratio and oxygen to ethanol ratio should be minimized. When the reformer and SOFC are operated at temperature of 700 oC and 900 oC, steam to ethanol ratio of 2, and oxygen to ethanol ratio of 0.1, the electrical performance of SOFC-SR shows its maximum value because this reforming process gives the highest hydrogen yield. However, since an internal reforming of methane in the SOFC was also considered, the electrical performance of the SOFC system with different reforming systems is slightly different. The thermal efficiency of SOFC systems can be improved by increasing the oxygen to ethanol ratio because the exothermic oxidation reaction is more pronounced producing more heat to the SOFC system. Furthermore, a design of heat exchanger network based on a pinch analysis was proposed in this study to reduce utility used in the SOFC systems.