Enhancing inter-particle microwave discharge for efficient coke-CO2 gasification

Abstract

To mitigate the adverse effects of catalyst volatilization and deactivation on CO2 gasification, we present a simple and feasible method for enhancing CO2 gasification by enhancing the inter-particle microwave discharge without adding a catalyst. This results in an 18.0%–30.6% increase in carbon conversion with similar energy consumption, demonstrating that the enhanced reactivity provided by the microwave discharge is comparable to conventional catalysts (Na, Fe, and K) for CO2 gasification. Experimental and simulation results reveal that enhancing the inter-particle microwave discharge raises the content of excited CO2 states, particularly high-level states. This is beneficial in reducing the activation barrier for the dissociative adsorption of CO2, which has the highest activation barrier of 406 kJ·mol−1. In conclusion, this study enhances the understanding of the mechanism for CO2 gasification without a catalyst and provides new insight into reactions prone to catalyst deactivation.