Performance characteristics of a novel integrated gasification chemical looping combustion for solid fuels

A novel Integrated Gasification Chemical Looping Combustion (IGCLC) process has been recently devised by our group for combustion of solid fuels, particularly coal. The proposed process incorporates an ex-situ step for gasification of the solid fuel but unlike conventional ex-situ methods the gasification process is fully integrated with the combustion process. This is achieved using a three-step chemical loop for production of hydrogen, combustion of gaseous fuels and regeneration of metal oxides. In the previous study, the feasibility of the process has been thermodynamically investigated. The current work is to mainly investigate the effect of the steam conversion rate, the temperature of the Air Reactor (ie AR) and Steam Reactor (ie SR), and the oxygen carrier circulation rate on the system operation and performance. In terms of the gasification temperature and syngas selectivity, high steam conversion rates (>0.35) are preferred. However, the total efficiency decreases with increasing steam conversion. The negative effect on the efficiency can be offset by rising the temperature of AR. Furthermore, the optimum in the oxygen carrier circulation is found to be 40% excess stoichiometric value and higher than 95% is found to be unacceptable.