不同流型下离子液体-MEA复合工质降膜吸收CO_2特性

以氨基酸离子液体和乙醇胺混合水溶液为吸收剂研究逆流气体对竖直平板降膜流型转换的影响,考察了3种流型下液体流量和入口温度、气体流量和进口CO2浓度对CO2吸收性能的影响。结果表明:随着液体流量的增加,液膜呈现溪流、片状流和完整流3种流型,降膜流型转换临界流量随逆流气体流量增大而增加;溪流和片状流时CO2吸收速率随液体流量的增加而增加,但在完整流条件下基本不变;完整流下具有较高的CO2吸收速率,然而溪流下的液相传质系数最高。

Falling film absorption of CO2into ionic liquid-MEA mixed solutions with different flow patterns

Carbon dioxide absorption into a mixed aqueous solution of functional ionic liquid, tetramethyl ammonium glycinate (N₁₁₁₁]Gly]) and monoethanolamine (MEA) was performed in a plate falling film reactor with different flow patterns. The effect of countercurrent gas flow on flow pattern transition was investigated. Absorption of carbon dioxide into the mixed aqueous solution of MEA and N₁₁₁₁]Gly] was studied with different liquid flow rates, liquid temperatures, gas flow rates and inlet carbon dioxide concentrations. Falling liquid film was found to take the patterns of corner rivulet flow, falling film flow with dry patches, and complete falling film flow depending on gas and liquid flow rates. Reduction of gas flow rate could lower critical flow rate of pattern transition. Absorption rate increased with increasing liquid flow rate with flow patterns of corner rivulet flow and falling film flow with dry patches, and then became unchanged with the pattern of complete falling film flow. CO₂ absorption rate reached a maximum with the pattern of complete falling film flow, however, corner rivulet flow had the largest liquid phase mass transfer coefficient.