Experimental and Numerical Investigation of Thermal Plasma Synthesis of Silicon

Experimental and numerical investigations were carried out on synthesis of Si from SiO2 using thermal plasma reactor. Temperature profile and gas flow distribution in the thermal plasma reactor were developed by the computational fluid dynamics (CFD) with ANSYS Fluent. The predicted temperatures are in good agreement with the experimentally measured temperatures in the reactor. Experiments were carried out at power 22.5 kw, SiO2 feed rate of 4 g/min, molar ratio of SiO2 to methane varied from 1 to 4:1. Samples from different sections of the reactor are collected and characterized using SEM and XRD. Effect of molar ratio of SiO2 to methane on the yield of Si showed that increase in molar ratio increased the Si yield. Based on the analysis of experimental and numerical results, a mechanism of thermal plasma synthesis of Si from SiO2 is proposed.