A simple model for comparative evaluation of different oxygen carriers and solid fuels in iG-CLC processes

Abstract

A simple model based on oxygen carrier kinetics has been developed for the in situ Gasification Chemical Looping Combustion (iG-CLC) process. Once the kinetic parameters for different oxygen carriers and solid fuels are known, the model allows easy and fast comparison of different oxygen carrier-solid fuel pairs, which is the main purpose of the model here presented. The comparison is based on the estimation of the CO2 capture efficiency value (ηCC) and the total oxygen demand (ΩT) as evaluating parameters. To show the proposed procedure for the comparison, two Fe-based oxygen carriers (ilmenite and Tierga ore), and five different types of solid fuels: anthracite (Yangquan), sub-bituminous (Tremedal), two bituminous coals (Cerrejón and Taldinsky) and one biomass (olive tree pruning) have been considered. The comparison of the calculated CO2 capture efficiency and total oxygen demand must be done including the effect of operating conditions such as temperature and solids circulation rate. A set of optimized operating conditions are given as a reference for future evaluations of different oxygen carrier-solid fuel pairs. This method is thought as a useful tool for a preliminary evaluation of new oxygen carriers for iG-CLC with different solid fuels.