Study On Thermodynamics Of Trichlorosilane Synthesis System

Trichlorosilane is an important raw material for the production of polysilicon and organosilicon monomer.Currently,the predominant trichlorosilane production technologies include direct chlorination technology and hydrochlorination technology.The former involves gas-solid heterogeneous phase reaction in fluidized bed reactor using metallurgical grade silicon powder and HCl,while the latter using metallurgical grade silicon powder,SiHCl₃ andH₂ The performance of the reaction is affected by the reaction temperature,pressure,ratio of feed,silicon particle size,pressure difference and catalyst.Through application equilibrium modules of thermodynamic computing software,HSC Chemistry,the complex chemical reactions and relevant influencing factor in the Si-H-Cl system relevent toSiHCl₃ synthesis were studied.Firstly, thermodynamic parameters of direct chlorination technology in different condition were computed to get data sheet,such as gas phase equilibrium composition,silicon conversion,selectivity and yield ofSiHCl₃,and tendency chart of gas phase equilibrium composition,silicon conversion,selectivity and yield ofSiHCl₃ under different temperature,pressure andn⁰_HCl/n_Si ⁰.Secondly,thermodynamic parameters of hydrochlorination technology in different condition were computed to get data sheet,such as gas phase equilibrium composition,selectivity and yield ofSiHCl₃,and tendency chart of gas phase equilibrium composition,silicon conversion,selectivity and yield ofSiHCl₃ under different temperature,pressure andn⁰_H2/n⁰_SiCl4.Finally,the simulation data was compared with the operational data of industrial production device.it turned out that the simulation results are quite different from the actual one.To figure out this problem,lab device ofSiHCl₃ synthesis was built to find out the influence factors through carring out a series of experiment.According to the experimental results,the industrial trichlorosilane synthesis reactor was transformed and some optimization suggestions were put forward for existing industrial equipment.