陶瓷膜接触器在润湿模式下吸收SO2的传质强化

Mass transfer enhancement of SO2 absorption via ceramic membrane contactor in wetting mode

将平均孔径为100 nm的Al2O3陶瓷膜组装成膜接触器,以单乙醇胺(MEA)为吸收剂,在考察吸收剂浓度对膜吸收过程影响的基础上,深入比较了陶瓷膜在润湿和非润湿模式下脱除SO2的传质性能.实验结果表明,当MEA浓度大于0.26 mol·L^-1时,润湿模式下SO2的脱除率和传质系数均高于非润湿模式.根据膜理论和阻力串联模型建立了陶瓷膜吸收SO2的传质方程,理论计算表明,润湿模式下膜相传质阻力因瞬间化学反应的存在大幅降低,润湿模式更适用于脱除烟气中低浓度的SO2.本研究结果可为陶瓷膜接触器在膜吸收领域的工业化应用和进一步传质优化提供参考.

In this work, a study of removing acid gas via ceramic membrane contactor was carried out with monoethanolamine(MEA) used as absorbent. Two kinds of Al2O3 ceramic membrane with hydrophobic and hydrophilic properties were assembled to the membrane contactor and operated at wetted mode and non-wetted mode, respectively. On the basis of investigating the influence of absorbent concentration on the absorption process, the mass transfer performance of ceramic membrane absorbing SO2 in the two modes was compared. The experiments showed that when the MEA concentration was higher than 0.26 mol·L^-1, the removal efficiency and mass transfer coefficient of SO2 in the wetted mode were higher than those in the non-wetted mode. The theoretical calculation indicated that the membrane mass transfer resistance in the wetting mode was greatly decreased because of the transient chemical reaction, and the wetting mode is more suitable for the removal of the low concentration of SO2 in the flue gas. The results of this work can provide reference for industrial application and further mass transfer optimization of ceramic membrane contactors in the field of membrane gas absorption.