Production method of refined trichlorosilane

Abstract

The invention relates to a method for producing purified trichlorosilane. The method comprises the following steps: (1) a preliminary tower is added at the rectification section of industrial trichlorosilane; (2) a heater is added in front of the preliminary tower to pre-heat feed; (3) the interior of the preliminary tower, the trichlorosilane tower and a silicon tetrachloride tower adopt the form of the compound of filler and trays; (4) silicon tetrachloride can come from the gas phase side at the lower part of the silicon tetrachloride tower; (5) the trichlorosilane tower and the silicon tetrachloride tower can be integrated into a tower or a double-effect distillation method is adopted; (6) a cleaning tower is added behind a dust catcher and in front of a condenser in a cooling section; (7) the cleaning tower adopts base waste heat to drive a lithium bromide set to generate cold water for cooling; (8) heat integration is carried out to synthesized heat so as to save energy and recycle heat; and (9) during the super pure distillation and purification process of trichlorosilane, 3 to 8 rectification towers and adsorption towers or complex distillation towers are adopted. The method has the advantages of low investment, low energy consumption, high purity of the target product, trichlorosilane, and the like.

Description

technical field [0001] The invention relates to a production method of chemical products and rectification separation and purification technology, in particular to a production method of refined trichlorosilane. Background technique [0002] Trichlorosilane is an important raw material for the production of solar-grade and microelectronic-grade polysilicon, and is also an important intermediate for the synthesis of organosilicon. It is used in the synthesis of organosilanes, alkyl groups, aryl groups, and organofunctional chlorosilanes. It is the most basic monomer in the agent, and it is also the raw material for the production of semiconductor silicon and single crystal silicon, and it can also be used to manufacture silicone compounds. With the rapid development of my country's economy, especially the rapid development of fine chemical industry, organic silicon industry, electronic products, optical fiber communication and other industries, it provides a huge market space...

AI Technical Summary

Problems solved by technology

[0004] The drying of silicon powder in the production process and the recovery of silicon powder by the bag filter require a large amount of heat, and the large amount of heat generated in the synthesis reaction cannot be fully recycled, resulting in great energy consumption and waste

In the cooling section, the mixture is directly sent to the condenser after dedusting. Since the mixture contains aluminum trichloride and other substances, these substances are very easy to crystallize and block the pipeline, which causes great inconvenience to the operation of the condenser, and often needs to be shut down for maintenance

For the rectification section, Chinese patent CN 1693192A proposes single-tower purification of trichlorosilane, and Chinese patent CN 1010455362A proposes double-tower separation of trichlorosilane, which cannot effectively separate trichlorosilane, low boiling matter and impurities such as boron and phosphorus. Removed, product indicators are also unstable

[0005] The present invention aims at the characteristics and requirements of the production process of trichlorosilane, improves the process of trichlorosilane, and proposes a method for the production and purification of trichlorosilane to solve the problem of large investment and energy consumption in the production of trichlorosilane High, low separation efficiency

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