Keshavarz P, Fathikalajahi J, Ayatollahi S
Petroleum and Chemical Engineering Department, College of Engineering, Shiraz University, Shiraz, Iran.
J Hazard Mater. 2008 Apr 15;152(3):1237-47. doi: 10.1016/j.jhazmat.2007.07.115. Epub 2007 Aug 7.
A steady state model was developed for a microporous hollow fiber membrane contactor operated under partially wetted conditions accompanied by chemical reactions, to analyze CO2 absorption into the aqueous solution of diethanolamine (DEA). The proposed diffusion-reaction model contains reversible chemical reactions in the liquid bulk as well as wetted parts of the membrane pores. A numerical scheme was employed to solve the simultaneous nonlinear mathematical expressions, and the results were validated with experimental data in the literature. The gas phase concentration and velocity profile in axial direction inside the shell, liquid concentration profile in axial and radial directions inside the fibers, and also those within the wetted parts of the pores were predicted by using the model. The results of the model and proposed numerical scheme show that membrane wetting, even in very low fractions, can decrease the absorption flux significantly. The wetting fraction of membrane was predicted both with and without consideration of chemical reactions inside the wetted pores. The results indicate that the chemical reactions inside the wetted pores, which have been disregarded in the literature, have considerable effects on the prediction of membrane wetting fraction.
建立了一个稳态模型，用于分析在伴有化学反应的部分润湿条件下运行的微孔中空纤维膜接触器中二氧化碳吸收到二乙醇胺（DEA）水溶液中的过程。所提出的扩散-反应模型包含液相主体以及膜孔润湿部分中的可逆化学反应。采用数值方法求解联立的非线性数学表达式，并将结果与文献中的实验数据进行了验证。利用该模型预测了壳程内轴向气相浓度和速度分布、纤维内轴向和径向液相浓度分布以及孔润湿部分内的浓度分布。模型和所提出数值方法的结果表明，即使膜的润湿率非常低，也会显著降低吸收通量。在考虑和不考虑润湿孔内化学反应的情况下，均对膜的润湿率进行了预测。结果表明，文献中忽略的润湿孔内的化学反应对膜润湿率的预测有相当大的影响。
