The Green Application On Extraction Separation Ethanol-Water With Ionic Liquids

Anhydrous ethanol is an important basic chemical and solvent, and it has extensive applications. Ionic liquids(ILs) have many advantages such as low vapor pressure, non-volatilization, wide rang steady temperature and steady chemical properties compared with the traditional organic solvents.The feasibility of using ionic liquids as solvents for the separation of the azeotropic mixtures of water and ethanol by extractive distillation is researched in this study.In this study, a new ebulliometer is used,and the T, x, y data were measured for ternary systems containing: water,ethanol,[CH₂CH₂OHMIM][BF₄],[CH₂COOHMIM] [BF₄],[CH₂COOCH₃MIM] [BF₄],[CH₃CH₂CH₂CH₂MIM]Clat P = 101.3 kPa and at IL mass fractions 30%. From the experimental data, relative volatility and activity coefficients of the volatile components were obtained. Results showed that:ILs with different function groups have different effects on water-ethanol system, the results are as follows: The experimental data were correlated by the NRTL model. The correlated results showed that the models could be used to direct the Process designChoosing [CH₃CH₂CH₂CH₂MIM]Cl as solvent, simulate the extraction distillation when different feed stage and different reflux ratio, the ethanol concentration of the tower top production was above 99.56%.Smaller size experiment showed that: in practice the ethanol concentration of the tower top production was 99.49%, it is a kind of excellent extractive solvent of extractive distillation of water-ethanol system.