Feasibility analysis of SO2 absorption using a hydrophilic ceramic membrane contactor

Abstract

Abstract Hydrophilic ceramic membranes would be potential candidates for membrane gas absorption if they could be applied to appropriate separation processes. This study highlights a novel concept for the practical implementation of SO2 absorption in hydrophilic ceramic membrane that exhibits outstanding thermal and mechanical stabilities. With this aim, we investigated experimentally the performance of SO2 absorption into aqueous sodium hydroxide (NaOH) solution in a hydrophilic alumina (Al2O3) membrane contactor in terms of SO2 removal efficiency and SO2 mass transfer flux, and compared the performance with that in a hydrophobic one. A series of experiments were performed at various conditions over a NaOH concentration range of 0–1.0 mol·L− 1, a liquid flow rate range of 30–180 ml·min− 1, a gas flow rate range of 120–1000 ml·min− 1, an inlet SO2 concentration range of 400–2000 μl·L− 1, and a temperature range of 10 –35 °C. It was found that the hydrophilic membrane was more competitive when using a NaOH concentration higher than 0.2 mol·L− 1. Furthermore, it can be inferred that the hydrophilic α-Al2O3 membrane exhibited exceptional long-term stability under 480 h continuous operation.