Photocatalytic reactive distillation - A novel process intensification approach for purification of electronic-grade silicon tetrachloride

Abstract

In order to remove the hydrogen-containing impurities in silicon tetrachloride which are difficult to remove because of the exceptionally low content, a photochlorination reactive distillation process has been proposed to obtain the electronic-grade silicon tetrachloride in this paper. The photochlorination reaction kinetics of C-H compound impurity was studied to verify the photochlorination reactive distillation process. The influence of the key factors in the photochlorination process, such as structure of tubular reactor and the layout of the ultraviolet light, on the content of methylchlorosilane (CH3SiCl3) was investigated in tubular reactor. The industrial production experiments and corresponding simulation of the photochlorination reaction followed by distillation process to conduct deep separation of trace amounts of CH3SiCl3 in silicon tetrachloride raw material were studied to verify the feasibility of process and the accuracy of model. Furthermore, the photochlorination reactive distillation process was proposed to execute further process intensification of purification process of silicon tetrachloride. Finally, after sensitivity analysis and optimization, the photochlorination reactive distillation process achieved 1626.82 $/year TAC savings compared with the photochlorination reaction followed by distillation process.