Mass-Transfer Characteristics and Optimization of a Hydrophilic Ceramic Membrane Contactor for SO2 Absorption
journal contributionposted on 31.10.2019, 12:05 by Xiangli Kong, Minghui Qiu, Kaiyun Fu, Xingyin Gao, Peng Xu, Dawei Gong, Xianfu Chen, Yiqun Fan
Postcombustion SO2 capturefrom a high-volume flue gascalls for a separator which should possess a high gas/liquid ratio concurrently without causing liquid flooding and entrainment. This study aimed to evaluate the feasibility of a hydrophilic ceramic membrane for SO2 separation by investigating the mass-transfer characteristics of SO2 absorption into NaOH coupling with a tubular Al2O3 membrane. We first established a numerical two-dimensional model to simulate the SO2 absorption process with respect to the available experimental data. Then, we analyzed the mass-transfer characteristics by simulating the distributions of SO2 and OH– in the membrane contactor and estimating the resistances of SO2 transfer in different phases. Simulations showed that the SO2–NaOH reaction was quite rapid and mostly occurred in the gas/liquid interface, leading to a minor membrane-phase resistance. Furthermore, effective NaOH concentration lines under several key membrane parameters and operating conditions were proposed to facilitate the design of a membrane contactor.