异丙醇-水-碱/乙二醇物系常压汽液平衡数据的测定

Vapor-Liquid Equilibrium of Isopropanol-Water-Alkali/Glycol System at Atmospheric Pressure

在常压下,用循环式汽液平衡釜测定了异丙醇-水-氢氧化钾(氢氧化钠或醋酸钾)/乙二醇物系的汽液平衡数据,其中,氢氧化钾(氢氧化钠或醋酸钾)/乙二醇作为复合溶剂,V(复合溶剂)∶V(异丙醇-水)分别为0.5∶1,1∶1,2∶1。实验结果表明,氢氧化钾(氢氧化钠)/乙二醇复合溶剂可消除异丙醇-水的共沸点,并显著提高异丙醇-水的相对挥发度;当脱除复合溶剂后液相异丙醇的摩尔分数小于80%时,氢氧化钾(氢氧化钠)/乙二醇复合溶剂对异丙醇-水的分离效果优于醋酸钾/乙二醇复合溶剂。用W ilson模型对实验数据进行关联,汽相组分的平均偏差小于0.02。

Vapor-liquid equilibrium（VLE）of isopropanol-water-alkali/glycol system was measured at atmospheric pressure. The alkali referred to potassium hydroxide or sodium hydroxide or potassium acetate. In the above system, glycol containing potassium hydroxide or sodium hydroxide or potassium acetate formed a composite solvent. The volume ratios of composite solvent to isopropanol-water were 0.5 ： 1,1 ： 1 and 2 ： 1, respectively. Thermodynamic consistency for experimental data of isopropanol- water system was confirmed by means of Herington method. Azeotropic point of isopropanol-water could be eliminated by adding composite glycol solvent containing potassium hydroxide or sodium hydroxide. When mole fraction of isopropanol in liquid phase was less than 80% after removal of composite glycol solvent from the system, the increase of relative volatility of isopropanol-water by composite glycol solvent containing potassium hydroxide or sodium hydroxide was obviously larger than that of containing potassium acetate. VLE data were correlated with Wilson model. Results showed that average deviation of vapor-phase composition was less than 0.02.