三元低共熔离子液体中CO2的吸收

由N, N-二甲基乙酰胺、氯化胆碱、乙二醇或丙三醇以不同的摩尔比(1:1:3, 1:1:4)合成了一系列三元低共熔离子液体(n_DMA:n_CC:n_{ethylene glycol}=1:1:3, 1:1:4, n_DMA:n_CC:n_glycerol=1:1:3, 1:1:4)。在293.15～323.15 K温度下, 间隔10℃, 0～600.0 kPa压力范围内, 用等温饱和法测量了CO₂在三元体系中的溶解度。CO₂在体系中的溶解度随压力增大呈线性增大趋势, 随温度升高而减小。计算了亨利常数, 结果表明, CO₂在由N, N-二甲基乙酰胺, 氯化胆碱, 乙二醇以摩尔比1:1:3合成的三元体系, 温度为293.15 K下, 亨利常数最小, 最小值为2.174 MPa·kg·mol^-1。报道了关于CO₂吸收的热动力学性质, 包括焓变、熵变、Gibbs自由能变。其中, 焓变为负值, 说明此吸收为放热过程。

Absorption of CO2 in a novel ternary deep eutectic solvent

A series of novel ternary deep eutectic solvents (TDESs) were synthesized from N, N-dimethyl acetamide (DMA), choline chloride (CC) and ethylene glycol or glycerol with different mole ratios (n_DMA:n_CC:n_{ethylene glycol}=1:1:3, 1:1:4, n_DMA:n_CC:n_glycerol=1:1:3, 1:1:4). Solubilities of CO₂ in TDESs were determined in the temperature range T=293.15—323.15 K with 10℃ intervals under pressure ranging from 0 to 600.0 kPa using the isochoric saturation method. The solubility of CO₂ in the liquids increased linearly with increasing pressure and decreased with increasing temperature. Henry's constants were calculated, while TDES obtained from DMA, CC and ethylene glycol with mole ratio 1:1:3 showing the lowest value of 2.174 MPa·kg·mol^-1 at 293.15 K. Thermodynamics of CO₂ absorption were also calculated, including enthalpy, entropy, Gibbs free energy. The negative enthalpy demonstrated that the process was exothermic.