Computational fluid dynamics simulation for dual-phase membrane module for CO2 capture: Effect of membrane thickness, temperature and CO2 feed concentration

Abstract

CO2 capture and natural gas purification are of paramount significance in power plant applications nowadays. Dual-phase membrane is an effective approach for the enhancement of CO2/CH4 separation efficiency. In this study, CO2/CH4 binary gas mixture separation was simulated by using hydroxide/ceramic dual-phase (HCDP) membranes incorporated in the industrial-scaled tubular membrane module. Computational fluid dynamics (CFD) was utilized as the approach to model the fluid flow within the membrane module. Utilizing the CFD modeling of membrane module, the effects of tubular membrane thickness, operating temperature and CO2 feed concentration on the separation performance of HCDP membrane had been investigated. The results showed that membrane thickness affected the effective surface area of the membrane and CO2 permeance. The greater the membrane thickness, the lower was the membrane separation efficiency. The highest CO2 recovery obtained was 90.12% at 1 mm tubular membrane thickness, with the membrane stage cut ratio of 0.1950. Operating temperature imposed a notable influence on the gas permeance as well. By increasing the operating temperature, CO2 permeances were improved and hence, the separation performance of HCDP membrane was enhanced simultaneously. As for the effect of CO2 feed concentration on the membrane performance, it was found that the overall membrane performance and separation efficiency were better when the CO2 feed concentration was low, due to the higher availability of the adsorption sites on the membrane surface. In conformity with the membrane technology as a cost-effective CO2 sequestration technique, the dual-phase membrane has demonstrated a remarkable potential to be adopted for industrial applications.