2017 Volume 50 Issue 12 Pages 871-877
The equilibrium concentrations of SiHCl3 and SiCl4 in the SiCl4–H2 system are investigated on the basis of thermodynamic data for the corresponding pure compositions under specified thermodynamic parameters. Eight independent reactions in the SiCl4–H2 system for hydrogenation of SiCl4 to SiHCl3 are obtained. Furthermore, the factors (such as temperature, pressure, and feed mole ratio) influencing the equilibrium concentrations of SiCl4 and SiHCl3 are studied. Diagrams of the equilibrium concentrations of SiCl4 and SiHCl3 as a function of temperature, pressure, and feed mole ratio are presented. Finally, the optimal thermodynamic conditions in the SiCl4–H2 system for hydrogenation of SiCl4 to SiHCl3 are determined to be 1,100°C, 0.3 MPa, and a feed molar ratio of 4. Under these conditions, the conversion ratio of SiCl4 to SiHCl4 is about 25%, compared to a value of less than 20% in actual production.