甲酸-水-N-甲基吡咯烷酮体系等压汽液平衡的研究

Isobaric vapor-liquid equilibria for water-formic-acid-N-methylpyrrolidone

在常压下测试甲酸-水、甲酸-N-甲基吡咯烷酮、水-甲酸-N-甲基吡咯烷酮的汽液平衡数据。考虑甲酸在汽相中的缔合效应,用维里方程和Hayden-O'connell关联式修正了汽相的非理想性,并用非线性最小二乘法关联前2对二元体系的汽液平衡数据,得NRTL和Wilson方程的模型参数。以NRTL模型参数预测三元体系汽液平衡数据,温度平均偏差为1.76℃,甲酸的汽相平均偏差为0.032 2,水的汽相平均偏差为0.040 4;以Wilson模型参数预测三元体系汽液平衡数据,温度平均偏差为1.66℃,甲酸的汽相平均偏差为0.027 5,水的汽相平均偏差0.011 6,可见2个模型预测值均与实验值吻合良好,而Wilson模型的关联精度较高。

Abstract： Isobaric vapor-liquid equilibria （VLE） data for formic acid-N-methylpyrrolidone, formic acid-N-methylpyrrolidone, waterformic acid-N-methylpyrrolidone systems was measured at 101.33 kPa. The binary data was correlated by NRTL and Wilson models and the binary interaction parameters were gotten by applying the non-linear least square method. The obtained models parameters from binary data were used to predict the ternary VLE data. When NRTL model was used, the average absolute deviations （AAD） in vaporphase mole fraction of formic acid and water were 0. 032 2 and 0. 040 4 respectively and AAD in the equilibrium temperature was 1.76℃. When Wilson model was used, the AAD in vapor-phase mole fraction of formic acid and water were 0. 027 5 and 0. 011 6 respectively and AAD in the equilibrium temperature was 1.66 ℃ From the prediction ternary VLE data results, both of the predicted values agree well with the experimental values. It can be concluded that NRTL model is better than Wilson model.