中空纤维膜接触器烟气脱硫壳层传质的研究

Mass transfer performance in shell side of hollow fiber membrane contactor for flue gas desulfurization

采用自制聚丙烯中空纤维膜接触器对模拟烟气进行脱硫,主要研究脱硫过程中膜接触器壳层传质情况。用SO2和N2配制模拟烟气,以NaOH溶液为吸收液,气体走管程,液体走壳层,考察了壳层空隙率、吸收液流量和摩尔浓度、气体流量等操作条件对脱硫过程中壳层传质的影响。研究发现,在空隙率较大的情况下,壳层传质系数随吸收液的浓度或吸收液流量的增大而增大;而在空隙率较小的情况下,随着膜丝分布不均的出现会导致死区和沟流的存在,对壳层传质有一定阻碍作用。气体流量的改变对壳层传质几乎没有影响。

A self-made polypropylene hollow fiber membrane contactor has been developed for flue gas desulfurization and the mass transfer properties through the membrane contactor are studied. The effects of void fraction of shell side,absorption liquid flow and concentration,and flue gas flow on mass transfer behavior are investigated by using the mixture of SO2and N2as model flue gas,sodium hydroxide solution as absorption liquid. In this study,the model flue gas and absorption liquid flow through the inner side of the contactor and the shell side,respectively. The results show that under a high void fraction,the mass transfer coefficient increases with increasing the concentration and the flow rate of the absorption liquid. While under a low void fraction,the dead zone and the channeling caused by the mal-distribution of the membrane lead to a decrease in the mass transfer coefficient. In addition,the gas flow rate has little effect on the mass transfer coefficient.