Study Of Separation And Vapor-liquid Equilibria For Fluoride-alcohol Compounds

The dissertation focused on the separation of 2,2,3,3-tetrafluoro-1-propanol,2,2,3,3,4,4, 5,5-octafluoro-1-pentanol, fluorides (inorganic) and polymer. The saturated vapor pressure of 2,2,3,3-tetrafluoro-1-propanol,2,2,3,3,4,4,5,5-octafluoro-1-pentanol were estimated and the vapor-liquid equilibrium (VLE) of methanol+2,2,3,3-tetrafluoro-1-propanol, methanol+2, 2,3,3,4,4,5,5-octafluoro-1-pentanol and 2,2,3,3-Tetrafluoro-1-propanol+2,2,3,3,4,4,5,5 octafluoro-1-pentanol system were studied respectively at atmospheric pressure (101.3 kPa) and low-pressure. Densities and viscosities of 2,2,3,3-tetrafluoro-1-propanol,2,2,3,3,4,4,5,5-octafluoro-1-pentanol binary system were measured at different temperatures.During the synthesis of 2,2,3,3-tetrafluoro-1-propanol by polymerizing TFE and methanol, a lot of offal were created. The offal consisted of 2,2,3,3-tetrafluoro-1-propanol and 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, sodium fluoride, barium fluoride and polymer. To separate the compounds, a solvent was needed to dissolve the polymer. Methanol is selected in this paper as the solvent. The amount of methanol and the other separation conditions were determined by experiment. The preferred separation conditions are as follows:the offal, 100g, methanol,200g, and the mixture was extracted twice. The ethanol,2,2,3,3-tetrafluoro-1-propanol and 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, respectively, were recovered by distillation. The polymer left could be burned.The vapor pressure of 2,2,3,3-tetrafluoro-1-propanol and 2,2,3,3,4,4,5,5-octafluoro-1-pentanol were calculated by correspounding state with group contribution(CSGC) equation. The Antoine equation parameters were correlated. The vapor-liquid equilibrium (VLE) data of methanol+2,2,3,3-tetrafluoro-1-propanol, methanol+2,2,3,3,4,4,5,5-octafluoro-1-pentanol and 2,2,3,3-tetrafluoro-1-propanol+2,2,3,3,4,4,5,5-octafluoro-1-pentanol at atmospheric pressure (101.3 kPa) was measured with dual circulation method. Meanwhile, the VLE data of 2,2,3,3-tetrafluoro-1-propanol+2,2,3,3,4,4,5,5-octafluoro-1-pentanol at 80.0 kPa,66.7 kPa and 53.3 kPa were measured, respectively. The thermodynamic consistency of the VLE data was checked by Herrington method, D-J<10. The VLE data of the binary mixtures were correlated by the Wilson and NRTL activity coefficient models. In the meantime, the energy parameters of the Wilson and NRTL models were optimized. The vapor phase composition and bubble point temperature were calculated by Wilson and NRTL equations, the average deviation of temperature was less than 0.7 K, the average deviation of vapor phase composition was less than 0.008 at different pressures.Densities and viscosities of 2,2,3,3-tetrafluoro-1-propanol and 2,2,3,3,4,4,5,5- octafluoro-1-pentanol were measured at different temperatures. Viscosities of 2,2,3,3- tetrafluoro-1 propanol and 2,2,3,3,4,4,5,5 -octafluoro-1-pentanol were correlated with temperatures by the Andrade equation, the average deviation was less than 0.1; Densities of 2,2,3,3-tetrafluoro-1-propanol and 2,2,3,3,4,4,5,5- octafluoro-1-pentanol were correlated with temperatures by the corresponding equations, which the average deviation was less than 0.002.