Study And Application Of Vapor-Liquid Equilibrium For Methanol-Methylal-1-Butanol-1-(Methoxymethoxy)-butane-1-(Butoxymethoxy)-butane System

The dialkoxymethane(DAOM)compound can be used not only as an excellent organic solvent in the pharmaceutical and cosmetic industries,but also as an additive for clean diesel.The 1-(methoxymethoxy)-butane(FMMB)and 1-(methoxymethoxy)-butane(FBMB)compounds studied in this paper are obtained by catalytic synthesis of methylal(DMM)and 1-butanol(NBA)as raw materials.The vapor-liquid equilibrium(VLE)data of the DAOM compounds have not been reported.The isobaric VLE data for the four binary systems of methanol(MeOH)-FMMB,NBA-FMMB,NBA-FBMB,FMMB-FBMB and two ternary systems of MeOH-NBA-FMMB,NBA-FMMB-FBMB were measured at 101.33 kPa using a vapor-liquid double-cycle Rose phase equilibrium kettle.The Wilson,NRTL and UNIQUAC activity coefficient model were used to correlate the measured binary VLE data,and the binary interaction parameters were obtained.The VLE data of two ternary systems were regressed and predicted by the model parameters obtained by the binary system correlation and the experimental data agree well with the predicted values of the model.For the extraction and separation of the NBA-FMMB binary system azeotrope,N,N-dimethylformamide(DMF)was selected as the extractant.The isobaric VLE data of NBA-DMF,FMMB-DMF and NBA-FMMB-DMF were first measured at 101.33 kPa using a vapor-liquid double-cycle Rose phase equilibrium kettle.The Wilson,NRTL and UNIQUAC activity coefficient model equations were used to correlate the measured binary VLE data,and the binary interaction parameters were obtained.The VLE data of ternary system were predicted by the model parameters obtained by the binary system correlation and the experimental data agree well with the predicted values of the model.The simulation was processed in Aspen Plus on the basis of the phase equilibrium research results.Activity coefficient model of NRTL was selected as the optimized thermodynamic model that used in the simulation process.The effects of reflux ratio,theoretical plate number and feed position on the separation effect was explored through sensitivity analysis.The whole process was optimized,and the results provided crucial essential data for the future industrialized design.