Thermodynamic Study on SiCl4 Hydrogenation System in Siemens Process

概要

論文の詳細を見る
Based on the thermodynamic data for related pure compositions, the fifteen possible chemical reactions in the SiCl4 hydrogenation system in Siemens process have been studied in this paper. The curves of ΔGmθ-T for the fifteen chemical reactions in the system are fitted. The five independent reactions in the process have also been obtained and the relations of and temperature have been fitted. Furthermore, diagrams of the equilibrium gas phase composition versus temperature under 1 atm, 3 atm, 5 atm and the feeding mole ratio (xH2/xSiCl4) of 2:1, 3:1, 4:1 have been plotted. Finally, the influencing factors (such as temperature, pressure and the feeding molar ratio) on the transformation ratio from SiCl4 to SiHCl3 have been studied. The diagrams of η-transformation ratio are presented as a function of temperature, pressure and feeding mole ratio respectively. The optimum operation parameters in the actual production are determined by the thermodynamic and kinetic studies. The results show that the condition of 1100°C, 3 atm and feeding mole ratio ( ) of 4 is best. Under the condition, the transformation ratio from SiCl4 to SiHCl3 is 24.81% against less than 20% in actual production.