CO2在Na2Cr2O7溶液中的平衡溶解度模型

为研究重铬酸钠(Na₂Cr₂O₇)对CO₂溶解的影响, 本文在带有搅拌的气液相高压平衡釜内, 采用静态法测定了温度在313.2-333.2 K, 压力在0.1-1.9 MPa 范围内, 重铬酸钠浓度分别为0、0.361、0.650、0.901 mol·kg^-1 时, CO₂ 在Na₂Cr₂O₇溶液中的溶解度. 结果表明: (1) Na₂Cr₂O₇对CO₂ 的溶解有盐析效应; (2) CO₂ 在Na₂Cr₂O₇溶液中的溶解符合亨利定律, 并且CO₂溶解度是温度和Na₂Cr₂O₇浓度的函数, 且用改进的Setschenow方程和Peng-Robinson-Pitzer (PR-Pitzer)方程拟合了在此温度、压力及重铬酸钠浓度范围内的实验数据, 拟合效果较好, 并且其平均相对误差分别为4.24%和3.32%.

Equilibrium Solubility Modeling of CO2 in Na2Cr2O7 Solutions

The solubility of CO₂ in aqueous Na₂Cr₂O₇ solutions of different concentrations (0, 0.361, 0.650, and 0.901 mol·kg^-1) was measured in a stirred vapor-liquid high-pressure equilibrium cell using the static method at temperatures and pressures in the ranges of 313.2 to 333.2 K and 0.1 to 1.9 MPa, respectively. The results indicated that the phenomenon of CO₂ dissolved in aqueous Na₂Cr₂O₇ could be interpreted according to a “salting-out effect”. Furthermore, our solubility data for CO₂ in aqueous Na₂Cr₂O₇ was in agreement with Henry''s law, and the Henry constant appeared to be a function of temperature, pressure, and the concentration of Na₂Cr₂O₇. Two thermodynamic models were applied to correlate the experimental data, including the modified Setschenow and Peng-Robinson-Pitzer equations, and the averaged relative deviations were found to be 4.24% and 3.32%, respectively.