Equilibrium Concentrations of SiHCl₃ and SiCl₄ in SiCl₄–H₂ System for Hydrogenation of SiCl₄ to SiHCl₃

摘要

The equilibrium concentrations of SiHCl_(3) and SiCl_(4) in the SiCl_(4)–H_(2) system are investigated on the basis of thermodynamic data for the corresponding pure compositions under specified thermodynamic parameters. Eight independent reactions in the SiCl_(4)–H_(2) system for hydrogenation of SiCl_(4) to SiHCl_(3) are obtained. Furthermore, the factors (such as temperature, pressure, and feed mole ratio) influencing the equilibrium concentrations of SiCl_(4) and SiHCl_(3) are studied. Diagrams of the equilibrium concentrations of SiCl_(4) and SiHCl_(3) as a function of temperature, pressure, and feed mole ratio are presented. Finally, the optimal thermodynamic conditions in the SiCl_(4)–H_(2) system for hydrogenation of SiCl_(4) to SiHCl_(3) are determined to be 1,100°C, 0.3?MPa, and a feed molar ratio of 4. Under these conditions, the conversion ratio of SiCl_(4) to SiHCl_(4) is about 25%, compared to a value of less than 20% in actual production.