High-purity CO2 recovery following two-stage temperature swing adsorption using an internally heated and cooled adsorber

Abstract

The availability of relevant and efficient technologies to capture, store, and use carbon dioxide (CO2) is critical to reduce CO2 concentrations in the atmosphere and reach net-zero CO2 emissions. In this study, we captured CO2 by combining an adsorbent-packed heat exchanger with an internal heating and cooling process of thermal swing adsorption. A two-stage process was used to achieve CO2 purity greater than 90 % in the simulated flue gas because the single-stage process could only concentrate CO2 to ∼ 50 % purity. The results revealed that the volume of the second-stage adsorption heat exchanger is approximately-one-third of the first-stage adsorber because the CO2 concentration of the second-stage feed gas increases in the first stage, thereby leading to an increase in the adsorption capacity of the second stage. Maximum CO2 purity of 95 % was achieved using the rate of purge air flow and regeneration time in the second-stage regeneration process as operating parameters. The overall CO2 recovery ratio was ∼ 60 %. The results of the study indicate the need to enhance the recovery ratio for improved performance.