Thermodynamic evaluation of sorption-enhanced chemical looping gasification with coal as fuel

Chemical looping gasification (CLG) is regarded as an efficient way for the utilization of solid fuel and hydrogen-enriched syngas production. In this work, a thermodynamic analysis is carried out to evaluate the CLG performance of coal on the basis of Gibbs free energy minimization. In order to enhance the gasification process, CO2 sorption is employed and sorbents are circulated in the whole system. The influence of operating parameters on the CLG performance as well as heat requirement of the system is further examined. The results reveal that the addition of sorbent can promote the hydrogen production and provide the heat for the reaction in the fuel reactor (FR), whereas additional energy input is still required for the whole system. A proper increase of oxygen carrier circulation rate can achieve the auto-thermal condition of the system. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved