膜吸收CO_2过程中甘氨酸钾吸收剂对聚偏氟乙烯中空纤维膜的浸润研究

Wetting of polyvinylidene fluoride hollow fiber membranes during the absorption of CO_2 by potassium glycinate solution

研究了聚偏氟乙烯(PVDF)中空纤维膜接触器吸收CO2过程中,吸收剂甘氨酸钾(PG)溶液对微孔膜的浸润随操作时间的变化,分别考察了溶液浓度、温度、吸收时间等条件对膜浸润的影响。结果表明:PG溶液浓度越高,膜浸润程度越低;温度越高,膜浸润程度越大;膜浸润程度随着吸收时间的延长而不断增大。同时还研究了膜浸润对总吸收传质系数的影响,极小程度的膜浸润导致传质系数大幅下降,在0.5 mol/L,308.15 K条件下实验运行40 h后膜孔平均浸润率达到0.181,总传质系数下降幅度达88.33%。

Studies of wetting during the absorption of CO2 by potassium glycinate( PG) aqueous solution using hydrophobic polyvinylidene fluoride( PVDF) hollow fiber membrane contactors have been carried out under different operating conditions of concentration,temperature of absorbent and time. The results showed that the lower the concentration of PG and the higher the temperature of the absorbent,the higher the degree of wetting. The degree of membrane wetting increased after prolonged running times. The impact of membrane wetting on the overall mass transfer coefficient was also studied. The mass transfer coefficient increased significantly for only a tiny extent of membrane wetting. For a PG concentration of 0. 5 mol / L and a temperature of 308. 15 K,after running for 40 hours the average wetting ratio reached 0. 181 with an 88. 33% decrease in total mass transfer coefficient.