中空纤维膜结构对脱除烟气中CO_2影响的数值研究

Simulation on the Structure Effects of Hollow Fiber Membrane on CO_2 Removal from Flue Gas

相对于传统的脱碳方法,中空纤维膜脱除烟气中CO2是一种清洁、高效的技术方法。运用有限单元法建立了一个疏水性中空纤维膜脱除烟气中CO2的二维模型,考察了膜丝直径、壁厚、孔隙率、曲折因子、纤维膜根数、膜柱内径和长度等方面对CO2脱除率的影响,模型结果与实验值相符。结果表明四种吸收剂的脱除率从大到小依次为EDA>MEA>DEA>AMP。当液速为0.1 m·s–1、气速0.211 m·s–1、操作压力为0.1 MPa时,减小曲折因子、膜丝壁厚和膜柱内径,增大孔隙率、膜丝内径与膜柱长度都有利于膜吸收CO2。

Compared with traditional CO2 separation methods, the absorption of CO2 in flue gas with hollow fiber membrane is a clean and efficient decarbonization technology. This paper used the finite element method and established a 2D model of hydrophobic hollow fiber membrane for the removal of CO2 in flue gas. The CO2-removal efficiency was investigated from the membrane diameter, thickness, porosity, tortuosity, the number of fibers, membrane column diameter and length. The modeling results are consistent with the experimental values. The results show that the sequence of absorption efficiency of four absorbents is EDAMEADEAAMP. Decreasing the tortuosity, thickness, and column diameter, or increasing the porosity, fiber diameter, and membrane length, is beneficial to the membrane absorption of CO2 under the conditions of 0.1 m·s^–1 liquid velocity, 0.211 m·s^–1 gas velocity and 0.1 MPa operation pressure.