Evaluation of the CO2 gasification of residual char under a regeneration atmosphere via calcium‒based chemical looping gasification

Abstract

Calcium‒based chemical looping gasification plays a vital role in the utilization of carbon‒based fuels. In this study, the effects of various parameters in the regeneration of CO2 gasification of residual char were studied. Since the CO2 gasification of residual char was an endothermic reaction, the reaction rate increased with temperature. The maximum reaction rate appeared at a CO2 partial pressure of 80%. The carbon conversion rate of residual char increased upon increasing the CO2 capture capacity of sorbent. The CO2 gasification of residual char complied with the shrinking core model instead of the volumetric reaction model, and the municipal solid waste (MSW) char after CO2 gasification was cylindrical shape. The apparent activation energy decreased after adding a sorbent, showing that the CO2 gasification of residual char was improved by adding a sorbent. These results provide an approach to enhance the CO2 utilization in regenerator, outlets and help reduce the oxygen demand and heat losses.