Tetrachlorosilane hydrogenation system and method for preparing trichlorosilane by using same

Abstract

The invention provides a system for preparing trichlorosilane by hydrogenating tetrachlorosilane. The system comprises a silicon powder pretreatment unit, a tetrachlorosilane pressurization unit, a tetrachlorosilane heat exchange unit, a hydrogen pressurization unit, a hydrogen heat exchange unit, a vaporization heat exchange unit, a hydrogenation reaction unit, a dust removal unit and a condensation and separation unit. Through mutual cooperation of the above structural units, the system has the remarkable advantages of easy and convenient operation, continuous and stable running, energy conservation and consumption reduction. According to a method for preparing trichlorosilane by hydrogenating tetrachlorosilane disclosed by the invention, a catalyst does not need to be additionally added, a catalytic effect can be achieved by utilizing a metal chloride byproduct generated in the hydrogenation process of tetrachlorosilane, and a conversion rate can reach 25%-28%.

Description

technical field [0001] The invention relates to the technical field of silane production, in particular to a tetrachlorosilane hydrogenation system and a method for preparing trichlorosilane. Background technique [0002] The production of silane by the disproportionation method of trichlorosilane produces a large amount of silicon tetrachloride. The production of trichlorosilane by silicon tetrachloride and the reduction of production costs have become the focus of current development. The hydrogenation system is an important part of the silane production process, and it is of great significance to promote the recycling of its materials, improve its primary hydrogenation conversion rate and reduce the energy consumption of silane production. [0003] At present, domestic silicon tetrachloride reduction methods mainly include thermal hydrogenation, cold hydrogenation and hydrochlorination. Among them, thermal hydrogenation is easy to operate and has low technical requirement...

AI Technical Summary

Problems solved by technology

[0003] At present, domestic silicon tetrachloride reduction methods mainly include thermal hydrogenation, cold hydrogenation and hydrochlorination. Among them, thermal hydrogenation is easy to operate and has low technical requirements, but it has high energy consumption, low conversion rate and high investment cost. Therefore, in actual production It has been basically eliminated in application; hydrochlorination is widely used in actual production due to its low energy consumption, high conversion rate, and low investment cost, but it still has the problems of difficult operation and high technical requirements; and cold hydrogenation also has energy consumption Low conversion rate, relatively high conversion rate, and low investment cost, but due to high technical requirements, it is rarely used in actual production

[0004] And, in the existing cold hydrogenation process, there are at least the following defects: (1) the cost of the catalyst used in the main reaction is relatively high, and it needs to be dried and activated (need to be equipped with an activated hydrogen compressor and an electric heater); (2) The primary conversion rate of the reactor is relatively low, and the production efficiency is low; (3) the silicon powder recovered by the dry dedusting device is not thorough, and the gas phase entrains more, which affects the normal operation of the wet dedusting, and sometimes even needs to be stopped for cleaning; (4) the wet dedusting The dedusting device cannot completely handle the silicon powder and metal chlorides in the chlorosilane mixture gas, causing blockage of subsequent equipment and pipelines

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