CO2 regeneration in a packed bed reactor using zeolite 13X under microwave conditions

Abstract

This study explores CO₂ regeneration in a packed bed reactor using Zeolite 13X under microwave conditions, aiming to minimize energy consumption and maximize efficiency. Microwave irradiation as a heat source in CO₂ regeneration was applied after capturing CO₂ in adsorption due to the rapid heating ability of microwaves, while Zeolite 13X was selected due to its high selectivity and high CO₂ capture capacity. CO₂ concentrations of feeding gas were set to 5 % and 15 % throughout the adsorption process to simulate natural gas and coal fired flue gases, respectively. Several parameters such as cavity orientation of the microwave, regeneration temperature, and microwave initial power were varied to investigate optimum conditions of CO₂ regeneration by evaluating energy requirement, CO₂ purity and productivity, as well as temperature distribution for the regeneration process. While regeneration temperature and microwave initial power were changed from 45 °C to 80 °C and 5 W to 30 W, respectively, microwave cavity orientation was used either in E-mode or H-mode. The key findings show that around 20 % less energy was consumed when E-mode is used in the system. In addition, overall CO₂ purities were found to be more than 95 % for both conditions of 5 % and 15 % CO₂ concentrations. Considering temperature homogeneity of the solid sorbent in regeneration, at least 90 % homogenous temperature distribution was observed in all regeneration conditions.