含离子液体乙醇-水物系等压汽液平衡数据的测定

摘要

At 101.32 kPa, isobaric vapor-liquid equilibrium data for the ethanol-water and acetic acid-water system containing ionic liquid (IL) triethylammonium hydrogen sulfate ( [N2,2,2,H] HSO4) were measured in an Ellis still. The vapor-liquid equilibrium curve of the ethanol-water system began to deviate from the line when the mole fraction of [N2,2,2,h]HSO4 reached 5%. When the mole fraction of [N2,2,2,h]HSO4 was 10% or 20% , the deviation from the line increased. The salt effect of IL changed the relative volatility of water and ethanol > and even led to the disappearance of azeotropic point. The more IL was added to the system, the more obvious was the salt effect. The relative volatility of ethanol to water increased with the increase of IL. Compared with other ionic liquids, low-cost and high efficiency were advantages of the [N2,2,2,h] HSO4. It was concluded that [N2,2,2,h ] HSO4 could be used as an entrainer for extractive distillation of the ethanol-water system. The measured ternary data were correlated using the NRTL model and the correlated result was in agreement with the experiment data.%用Ellis双循环汽液平衡釜测定了101.32 kPa下乙醇-水-三乙基铵硫酸氢盐([N2,2,2,H]HSO4)的等压汽液平衡数据.实验结果表明,当[N2,2,2,H]HSO4的摩尔分数为5％时乙醇-水二组分物系的汽液平衡线就开始偏离,[N2,2,2,H]HSO4摩尔分数为10％、20％时,偏离程度增大；[N2,2,2,H]HSO4表现出盐效应,使乙醇对水的相对挥发度发生改变,消除了乙醇-水物系的共沸点；含量越大,盐效应越明显.随着[N2,2,2,H]HSO4含量的增加,乙醇对水的相对挥发度也随着增加；与其他离子液体相比较,[N2,2,2,H]HSO4具有低成本、高效率的优点,可以作为乙醇-水物系萃取精馏分离的有机盐.用NRTL模型对数据进行了关联,关联的结果和实验计算值相当,符合实验趋势.