Performance of sorption-enhanced chemical looping gasification system coupled with solid oxide fuel cell using exergy analysis

Abstract

Coal gasification system integrated with solid oxide fuel cell (SOFC) provides a promising energy conversion way owing to its high efficiency. To get a deep insight into the energy performance of this system, a thermodynamic evaluation is implemented. Meanwhile, the technologies of chemical looping and CO2 sorption are introduced into this integration system. It is found that the addition of oxygen carrier and sorbent into coal gasification system can promote the output power of the SOFC with a higher exergy destruction, where the exergy efficiency of most modules in the system can reach 80% except tar separation. The results also reveal that a suitable improvement of gasifying agent amount is beneficial to the energy performance of the system. When the H2O/C molar ratio is increased to 3.0, the SOFC exergy efficiency of 97% can be achieved.