Effects Of Ionic Liquids For Isobaric Vapor Liquid Equilibria On Three Azeotropic Systems And Their Activity Cofficient Moedls

In the extractive distillation of azeotrope,ionic liquids(ILs)have been regarded as a good new entrainer extraction agent because of its unique properties in recent years.The azeotropic systems of ethyl acetate-ethanol,chloroform-ethanol and chloroform-isopropanol are studied in this paper,and the ILs[MMim][DMP],[OMim][PF6]and[BMim][BF4]are used as entrainers to separate these azeotropic systems.The changes of equilibrium composition,relative volatility,activity coefficient and equilibrium temperature of these systems are studied.Meanwhile,the experimental data were fitted with Wilson,NRTL,e-nrtl and UNIQUAC model,which effectively extended the application scope of the thermodynamic model.On the basis of studying of the existing model deeply,the influence of the multi-process force in the local component model is considered.Then the Wilson-MR model is established,and the influence of the short-range and long range forces is analyzed.The Wilson-MR model is used to fit the vapor-liquid equilibrium(VLE)data containing ionic liquids,and it is compared with other models.In addition,with the help of Aspen Plus,ILs are designed as entrainer to optimize the process and get the best operating conditions,and they lay the foundation for practical production.The main research contents are as follows:VLE data of ethyl acetate-ethanol-[MMim][DMP],ethyl acetate-ethanol-[OMim][PF6]and ethyl acetate-ethanol-[BMim][BF4]were measured,and the activity coefficient model was fitted for the experimental data.With the increase of ILs contents in the ethyl acetate-ethanol-ILs system,azeotropic point was remove when the mole fraction of[MMim][DMP],[OMim][PF6]and[BMim][BF4]exceeded 0.048,0.141 and 0.353,respectively.The effects of three ILs on ethyl acetate-ethanol system were:[MMim][DMP]>[OMim][PF6]>[BMim][BF4].[MMIM][DMP]produced a salting-out effect on ethyl acetate,while[OMIM][PF6]and[BMIM][BF4]produced a crossover effect between salting-in and salting-out on ethyl acetate.For the ethyl acetate-ethanol system,[MMIM][DMP]is an excellent candidate entrainer.(2)VLE data of chloroform-ethanol-[MMim][DMP]were measured,and the activity coefficient model was fitted for the experimental data.With the increase of ILs contents in the chloroform-ethanol-[MMim][DMP]system,azeotropic point was remove when the mole fraction of[MMim][DMP]exceeded 0.058.[MMIM][DMP]produced a a crossover effect between salting-in and salting-out on chloroform.The addition of[MMim][DMP]to the chloroform-ethanol system raised the temperature of the system.The promotion of the ethanol boiling point was higher than that of chloroform.For the chloroform-ethanol system,[MMIM][DMP]is an excellent candidate entrainer.(3)VLE data of chloroform-isopropanol-[MMim][DMP]were measured,and the activity coefficient model was fitted for the experimental data.With the increase of ILs contents in the chloroform-isopropanol-[MMim][DMP]system,azeotropic point was remove when the mole fraction of[MMim][DMP]exceeded 0.045.[MMIM][DMP]produced a a crossover effect between salting-in and salting-out on chloroform.The addition of[MMim][DMP]to the chloroform-isopropanol system raised the temperature of the system.The promotion of the isopropanol boiling point was higher than that of chloroform.For the chloroform-isopropanol system,[MMIM][DMP]is an excellent candidate entrainer.(4)With the help of Wilson,NRTL,e-NRTL and UNIQUAC model,the activity coefficient model was used to correlate the experimental results.At the same time,the correlation results of these models were compared with experimental data,and it can be used to calculate the arbitrary concentration of the three system in this paper,which has great significance to study the extractive distillation in the future.(5)Wilson-MR,a new activity coefficient model,is established to calculate the activity coefficient.The influence of the short-range and long range forces is taken into account,and the results show that the model is especially suitable for calculation of ternary system containing ILs of activity coefficient.Wilson-MR model was contrasted with other models,and the advantages and disadvantages of the Wilson-MR model and further optimization direction is analyzed.(6)Aspen plus was used to design extraction azeotrope of ethyl acetate ethanol process containing[MMim][DMP].A series of factors related to optimal operating conditions was obtained,including feed,extractant circulation,equipment operation parameters,which lay the foundation for practical production.