乙酸乙酯-乙腈-离子液体三元混合物气液相平衡

Vapor-liquid phase equilibrium of ethyl acetate-acetonitrile-ionic liquid ternary mixture

为有效分离乙酸乙酯-乙腈共沸混合物,对含有离子液体的共沸体系进行了研究。在101.3 kPa下,对乙酸乙酯-乙腈-[N_(1,1,1,1)][NTF_(2)](四甲基铵双[(三氟甲基)磺酰基]酰亚胺盐)或乙酸乙酯-乙腈-[N_(2.2.2.2)][NTF_(2)](四乙基铵双[(三氟甲基)磺酰基]酰亚胺盐)三元物系的等压气液相平衡数据进行测定,探讨了2种离子液体对乙酸乙酯-乙腈的气液相平衡的影响。实验结果表明:离子液体的加入会使体系产生显著的盐析效应。乙酸乙酯-乙腈物系的相对挥发度随着体系中离子液体的摩尔分数增大而增大,当离子液体达到一定摩尔分数时共沸现象消失。分析实验数据并关联NRTL模型得到二元交互作用参数,计算出2种离子液体最小打破共沸所需摩尔分数分别为0.019和0.035,使用Aspen Plus软件模拟工艺流程并优化工艺参数,使用高斯软件计算三元组分各个分子间相互作用能进行机理分析。

In order to effectively separate the ethyl acetate-acetonitrile azeotropic mixture,the azeotropic system containing ionic liquid was studied.The isobaric vapor-liquid equilibrium data of ethyl acetate-acetonitrile-[N_(1,1,1,1)][NTF_(2)](tetramethylammonium bis[(trifluoromethyl)sulfonyl]imide salt)or ethyl acetate-acetonitrile-[N_(2.2.2.2)][NTF_(2)](tetraethylammonium bis[(trifluoromethyl)sulfonyl]imide salt)ternary systems were measured at 101.3 kPa,and the effects of two ionic liquids on the vapor-liquid equilibrium of ethyl acetate-acetonitrile were discussed.The experimental results show that the addition of ionic liquids makes the system produce a significant salting-out effect.The relative volatility of the ethyl acetate-acetonitrile system increases with the increase of the mole fraction of the ionic liquid in the system.When the ionic liquid mole fraction reaches to a certain concentration,the azeotropic phenomenon disappears.The experimental data were correlated with the NRTL model to obtain the binary interaction parameters and the minimum mole fraction of the two ionic liquids required to break the azeotrope were 0.019 and 0.035,respectively.Aspen Plus software was used to industrially simulate the process flow and optimize the process parameters.Gaussian software was used to calculate the intermolecular interaction energy of each component of the ternary component for mechanism analysis.