Font Size: a A A

The Determination And Correlation Of The Excess Enthalpies For The Binary System Of Alcohols+(Ketones, Or+Ionic Liquids) And The Application Of COSMO-type Model

Posted on:2009-06-27Degree:DoctorType:Dissertation
Country:ChinaCandidate:S Y LiFull Text:PDF
GTID:1101360245474327Subject:Chemistry
Abstract/Summary:PDF Full Text Request
Excess molar enthalpy is an important thermodynamic property.It reflects the degree of liquid mixtures deviated from ideal solution,and is one of primary sign to scale the nonideal property of solution.The study of excess molar enthalpy is not only helpful for explaining the structure of solution and understanding the interaction mechanism of molecules,but also can provide significant thermodynamic basic data for the design of chemical engineering process.In the development of theoretical model,the data of excess molar enthalpy can be used to calculate the interaction energy of different molecules,and correlate the macroscopic thermodynamic properties and microcosmic intermolecular interaction,molecular size and so on, which gives strong support for testing and developing theories of solution.Recent years,green chemists have great interest in ionic liquids because of their special properties,such as low volatility,low vapor pressure,wide liquid range, nonflammable,thermal stability up to high temperatures,regulative catalysis capability,repeatable use,little pollute to environment.The thermodynamic data are very important in the application of ionic liquids.Now the experiment data are very lack.In order to understand the thermodynamic property of ionic liquids and build the thermodynamic model,the reliable excess molar enthalpy data are very important.In the first chapter of this thesis,we introduced the class,mechanism and application of calorimeters,and the thermodynamic method(activity coefficient equation and state equation)in the study of excess molar enthalpy.The development trend of theoretical model was discussed and the research contents of this thesis were described.In the second chapter,the excess molar enthalpies of ketones +(alcohols, alkanes,water,and esters)at T=(298.15,313.15,328.15,338.15,348.15)K and P = (0.1,10.0)MPa were determined by CSC4400 flow mixing microcalorimeter.The experiment data were correlated by Redlich-Kister,Wilson,NRTL,UNIQUAC and modified Wilson model.Their advantages of these models were compared in the correlation of excess enthalpy data.In the third chapter,the interaction of 2,4-pentanedione and methanol and water were studied by quantum chemistry.The interaction energy of 2,4-pentanedione and methanol and water were explained from molecular view.In the fourth chapter,the development of COSMO-type model was introduced in detail.The vapor pressure,boiling point,Henry constant,partition coefficient,VLE and excess molar enthalpy of some system were predicted,and compared with literature.The effect of different calculated method on the(?)-profile and the predictive result of VLE and excess molar enthalpy were studied.The COSMO-SAC model was tried to be modified to give good predictive reuslt of excess molar enthalpy.Although some predictive results were not good,COSMO-type model was a successful model in the prediction of thermodynamic property as a new model.In the fifth chapter,the property,class,synthesis method and application of ionic liquids were introduced and some ionic liquids were synthesized and purified. The partial molar excess enthalpies at infinite dilution of some alcohols in ionic liquids were determined with ITC.The infinite dilution activity coefficients of alcohols in ionic liquids were predicted by COSMO-RS model and the partial molar excess enthalpies at infinite dilution were calculated from it.Although the predictive results had some deviation,COSMO-RS model could be still a valuable predictive model when experiment data were absent.In the last chapter,the work was summarized.We find the deficiencies in this thesis and propose the idea of the latter research.
Keywords/Search Tags:excess enthalpies, ionic liquids, Wilson model, NRTL model, UNIQUAC model, modified Wilson model, COSMO-type model
PDF Full Text Request
Related items