The Solid-Liquid And Vapor-Liquid Equilibria Of Systems Containing Ionic Liquids And Its Apllication In Extractive Distillation

The phase equilibria data about solutions containing ionic liquids (ILs) are crucialfor the applications of ILs in chemical industry. The solid-liquid equilibria data of ILs+polyols were measured and the vapor-liquid equilibrium of quaternary system2-methyl-2-propanol+water+propane-1,3-diol+[emim][Cl] was studied. Theprocess of the separation of2-methyl-2-propanol+water via extractive distillationwith ILs-based mixed solvent as entrainer was also simulated.Solid-liquid equilibria data for binary systems of1-ethyl-3-methylimidazoliumhexafluorophosphate ([emim][PF6])+polyols (ethane-1,2-diol, propane-1,2-diol,propane-1,2,3-triol) and ternary systems ([emim][PF6]+ethane-1,2-diol+propane-1,2-diol,[emim][PF6]+ethane-1,2-diol+propane-1,2,3-triol,[emim][PF6]+propane-1,2-diol+propane-1,2,3-triol) have been measured. The results show that thesolubilities of [emim][PF6] in single solvent decrease with the alkyl chain length andnumber of hydroxyl groups in polyols. The solubilities of [emim][PF6] in mixedsolvents at the same temperature are in the order of ethane-1,2-diol+propane-1,2-diol＞ethane-1,2-diol+propane-1,2,3-triol＞propane-1,2-diol+propane-1,2,3-triol. Thesolid-liquid data for the binary and ternary systems are correlated by the NRTLactivity coefficient equation, and the correlation results agree well with theexperimental results.The vapor-liquid equilibrium (VLE) data for2-methyl-2-propanol+water+propane-1,3-diol+[emim][Cl] were measured at101.3kPa. The results show that theazeotrope of2-methyl-2-propanol+water can be broken by the mixed solvent ofpropane-1,3-diol+[emim][Cl]. The experimental VLE data were correlated by NRTLactivity coefficient equation and the binary parameters were obtained. The correlationresults agree well with those of experimental.The mixture of propane-1,3-diol and1-ethyl-3-methylimidazolium chloride([emim][Cl]) was used as mixed solvent for the separation of2-methyl-2-propanol+water via extractive distillation. The effects of feed position, solvent feed position,solvent temperature, reflux ratio, solvent ratio and the ratio of propane-1,3-diol to[emim][Cl] in mixed solvent were investigated by the simulation results with thesoftware ChemCAD.