含离子液体醋酸-醋酸正丙酯物系等压汽液平衡

Isobaric vapor-liquid equilibria for acetic acid-n-propyl acetate system containing ionic liquids

用Ellis双循环汽液平衡釜测定在常压下2种醋酸正丙酯-醋酸-离子液体的等压汽液平衡数据,即醋酸正丙酯-醋酸-三丁基铵醋酸盐([N4,4,4,H][AC])和醋酸正丙酯-醋酸-三辛基铵醋酸盐([N8,8,8,H][AC])。实验结果表明:当加入[N4,4,4,H][AC]和[N8,8,8,H][AC]后,醋酸正丙酯-醋酸二组分物系的汽液平衡线发生了偏离,[N4,4,4,H][AC]和[N8,8,8,H][AC]表现出盐效应,醋酸正丙酯对醋酸的相对挥发度发生改变。离子液体对醋酸正丙酯-醋酸的盐效应顺序为:[N4,4,4,H][AC]>[N8,8,8,H][AC]。因此,[N4,4,4,H][AC]和[N8,8,8,H][AC]可以作为醋酸正丙酯-醋酸物系萃取精馏的溶剂,汽液平衡数据的测定可为分离过程优化设计提供依据。

The isobaric vapor-liquid equilibrium data for the n-propyl acetate-acetic acid containing ionic liquid （IL） were measured in an Ellis still at atmospheric pressure. The ionic liquids employed were tributylammonium acetate and trioctylammonium acetate. The vapor-liquid equilibrium curves of the n-propyl acetate-acetic acid system began to deviate from the line when the system contained ionic liquids. The salt effect of IL changed the relative volatility of n-propyl acetate and acetic acid. The salt effect on n-propyl acetate-acetic acid system decreased in the order ： [ N4,4,4,H ] [ AC ] 〉 [ N8,8,8,H ] [ AC ]. It concludes that [ N4,4,4,H ] [ AC ] and [ N8,8,8,H ] [ AC ] can be used as entrainers for the separation of n-propyl acetate and acetic acid.