Trichlorosilane production technique and system

Abstract

The invention provides a trichlorosilane production system which comprises an evaporator, a hot hydrogenation furnace, a cold hydrogenation reactor, a filter, a condenser and a purifying and separating column, wherein the hot hydrogenation furnace is connected with the cold hydrogenation reactor, and used for introducing tail gas obtained by hot hydrogenation into the cold hydrogenation reactor to perform reaction; the filter is connected with the cold hydrogenation reactor to filter the tail gas of the cold hydrogenation reactor; the evaporator is connected with the hot hydrogenation furnace, the filter and the condenser, and used for performing heat exchange on silicon tetrachloride and hydrogen used as raw materials and the filtered tail gas, and the tail gas is introduced into the condenser; the condenser is used for condensing the tail gas to obtain chlorosilane; and the purifying and separating column is used for separating and purifying the liquid chlorosilane. The invention also provides a trichlorosilane production technique. The trichlorosilane production system and technique provided by the invention can effectively utilize the waste heat of the hot hydrogenation tail gas and use the byproduct chlorine hydride generated by hot hydrogenation as the raw material to participate in the cold hydrogenation reaction, thereby lowering the power consumption, enhancing the raw material utilization ratio and lowering the overall operating cost.

Description

technical field [0001] The invention relates to a production process and system of trichlorosilane. Background technique [0002] Trichlorosilane is used as a raw material for polysilicon production, and its preparation methods are generally divided into thermal hydrogenation and cold hydrogenation. Thermal hydrogenation mainly uses silicon tetrachloride and hydrogen as raw materials, and is carried out at a high temperature exceeding 1,000 degrees to generate trichlorosilane. With hydrogen chloride gas, this reaction is an endothermic reaction. The cold hydrogenation is to use silicon powder, silicon tetrachloride and hydrogen as raw materials, and react in a cold hydrogenation reactor to synthesize trichlorosilane. The temperature required for cold hydrogenation is relatively low (about 550 degrees). [0003] However, the above two traditional trichlorosilane production processes have relatively low conversion rates and high energy consumption, resulting in relatively hig...

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Problems solved by technology

[0003] However, the above two traditional trichlorosilane production processes have low conversion rates and high energy consumption, resulting in relatively high production costs for trichlorosilane, which is also one of the reasons for the high cost of polysilicon

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