Vapor-Liquid Equilibria Prediction and Validation of Binary Systems Containing SiCl4 by Using the MOSCED Model

The measurement of olyzed VLE data of some binary system containing a deliquescent constituent is often difficult and time consuming. The MOSCED model was employed to predict the phase equilibria of the SiCl4-CS2 and SiCl4-C2H4Cl2 binary systems, which are easily hydrolyzed during the measuring process. The infinite dilution activity coefficients and activity coefficients of components of the SiCl4-CS2 and SiCl4-C2H4Cl2 binary systems were calculated. Then, VLE data and the VLE phase diagram of these binary systems were calculated using the trial-and-error method based on the obtained activity coefficients of the components of these binary systems. The calculated results are consistent with the experimental data within the allowable error. The result shows that the SiCl4-CS2 binary mixtures have closer bubble and dew point curves than SiCl4-C2H4Cl2 binary mixtures in the T-x-y phase diagram, which means that the SiCl4-C2H4Cl2 system is much more easily separated by distillation. Meanwhile, the VLE data and VLE phase diagram of SiCl4-CS2 and SiCl4-C2H4Cl2 binary systems were used to guide the process of separating high-quality SiCl4 from liquid waste originating from the titanium metallurgical industry.