High-performance carbon dioxide capture: 99% purity and 90% recovery using a low-temperature, two-stage membrane process

Abstract

An innovative membrane process has been designed in this study to capture carbon dioxide (CO2) from the flue gas of hydrogen reformers that achieves high CO2 purity and recovery. Membrane modules were used to investigate the difference in permeances between pure and mixed gases; the relationship between the permeances of CO2, O2, and N2 at different temperatures was examined. Differences in the activation energies of each gas at low temperatures resulted in improvements in CO2 selectivity. Utilizing this property, the CO2 purity and recovery in low-temperature processes were improved by approximately 10% (compared to the ambient conditions) in a single-stage operation. The performances of single- and two-stage processes were evaluated; a novel two-stage recycling configuration was developed to overcome the conventional limitations of single-stage membrane processes; CO2 purity of 99% and a recovery rate of 90% were achieved. The experimental results of the process were validated through mathematical modeling to ensure consistency, and the performance was simulated in terms of purity and recovery of each stage in relation to temperature. This paper contributes to enhancing the understanding and application of membrane processes for efficient CO2 capture from industrial flue gases.