Exergy Analysis of a Novel Chemical Looping Hydrogen Generation System Integrated with SOFC

Abstract

In this paper, a novel system integrating chemical-looping hydrogen generation (CLH) system and solid oxide fuel cell (SOFC) has been proposed. This new methane-fuelled energy system was investigated with energy balance and exergy analysis. CLH produces the hydrogen as the fuel of the SOFC, and the FeO and Fe3O4 are selected as the looping material. Waste heat from the SOFC is absorbed by the CLH and converted to chemical energy through the reduction reaction of CLH. Owing to the cascade utilization of the fuel between the CLH and SOFC, the net efficiency of this novel system can achieve 62.8% considering CO2 separation, more than 10 percentage points higher than a methane reforming fuelled SOFC system. Meanwhile, by using the CLH to produce the hydrogen, the CO2 can be recovered without an energy penalty. Through the analysis of the graphical exergy, the cascade utilization of waste heat and the high-efficiency hydrogen production is the main reason of high performance. This novel system also has the advantage of CO2 capture without energy penalty, so this combined system is an advantaged method to accomplish the efficient utilization of methane.