Vapor-liquid equilibrium calculation and application of TiCl4-CH2Cl2 system

The limiting activity coefficient for binary systems of TiCl4-CH2Cl2 was estimated by MOSCED model, and the value was 1.151 and 1.114 respectively for TiCl4 and CH2Cl2. According to the limiting activity coefficient, the activity coefficient of TiCl4-CH2Cl2 system was calculated by Wilson model. The results showed that the activity coefficient of TiCl4 decreased as the mole fraction of TiCl4 in the mixture increased, but the activity coefficient of CH2Cl2 increased as the increase of mole fraction of TiCl4 in the mixture. According to activity coefficient and theory of phase equilibrium, vapor-liquid equilibrium data of TiCl4-CH2Cl2 system was computed by try and error method, and the error was about 10%. Meanwhile, the phase diagram of T-x-y and y-x were drawn. The vapor-liquid equilibrium data indicated that the prefractionation of TiCl4 and CH2Cl2 could be reached by distillation, and the further separation could be achieved by rectification. The theoretical plate number of rectifying column for further separation of TiCl4 and CH2Cl2 was 4. The Raman spectra and limiting activity coefficient of TiCl4-CH2Cl2 system showed that there was no azeotrope and new species generated when titanium tetrachloride mixed with dichloromethane.