(422a) Computational Evaluation of Carriers in Facilitated Transport Membranes for Post-Combustion Carbon Capture
Incorporating molecular amines as mobile carriers in facilitated transport membranes (FTMs) has been demonstrated to significantly enhance the CO2 permeance and CO2/N2 selectivity of the membrane for CO2 capture from flue gas. In this study, by employing computational techniques such as the density functional theory, molecular dynamics studies, and Monte Carlo simulations, the role of mobile carriers is systematically studied at the molecular level from the perspectives of the amineâCO2 reaction chemistry, diffusivities of carriers and gases, and N2 sorption. The water uptake of FTMs with and without mobile carriers is also experimentally quantified. The introduction of mobile carriers is shown to enhance the diffusivities of CO2 reaction products and the water uptake compared to FTMs without mobile carriers. The choice of mobile carriers is also demonstrated to influence the separation performance. Computationally, certain carriers are shown to possess a faster reaction kinetics and a higher CO2 loading capacity; these carriers also demonstrate a better CO2 permeance experimentally. The good consistency between the computational and experimental observations validates the computational models employed and insights generated in this study. The outcomes of this work shed light on the future design and selection of carrier structures, and the adopted computational approaches can be employed to discover promising mobile carrier candidates.