Abstract:

The vapor liquid equilibrium test bench was set up, and the data of vapor liquid equilibrium of CO₂ in aqueous mixture of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim] [BF₄]) and monoethanolamine (MEA) were measured. The desorption energy consumption of this absorbent was calculated. The results showed that with the increase of temperature, the corresponding CO₂partial pressure of the solution increased, and the change of the mass fraction of[Bmim] [BF₄] had little influence on the vapor liquid equilibrium. Compared with 30% MEA, the main advantage of this absorbent in terms of energy consumption lies in the reduction of sensible heat and latent heat during desorption. The reaction heat decreased significantly after the CO₂ loading was greater than 0.45, and the decrease of latent heat was mainly due to the decrease of the partial pressure and mole fraction of H₂O in gas phase in the desorption tower. When the mass fraction of[Bmim] [BF₄] was bigger than 30%, the energy consumption of sensible heat could be decreased by more than 30%, and the main reasons for the decrease were the decrease of specific heat capacity and the increase of amine concentration in rich phase liquid.

Key words: CO₂ capture, vapor liquid equilibria, desorption energy consumption, ionic liquid, MEA

摘要：

搭建汽液平衡实验台，对液液分相CO₂吸收剂1-丁基-3-甲基咪唑四氟硼酸盐（[Bmim][BF₄]）/乙醇胺（MEA）混合水溶液与CO₂的汽液平衡进行了实验测量与分析，并对该吸收剂解吸能耗进行计算。结果表明，随着温度的升高，相同担载量溶液对应的CO₂分压升高，[Bmim][BF₄]质量分数的改变对汽液平衡的影响不明显。与传统有机胺溶液30%（质量）MEA相比，该吸收剂在能耗方面主要优势在于解吸过程中显热和潜热的减小。其反应热在担载量大于0.45之后明显减小，潜热的减小主要由于解吸塔内H₂O气相分压和摩尔分数的减小，当[Bmim][BF₄]质量分数大于30%时，显热可以减少30%以上，减少的原因主要为比热容的降低和富液胺浓度的提升。

关键词: 二氧化碳捕集, 汽液平衡, 解吸能耗, 离子液体, 乙醇胺