Silicomethane low-temperature production and byproduct comprehensive recycling process

Abstract

The invention belongs to the field of polysilicon technology, in particular to a silicomethane low-temperature production and byproduct comprehensive recycling process. Silicomethane belongs to a special gas in the past, is generally used for scientific research and has small demand. The requirement on the purity is brought forward at present along with rapid development of solar energy industry,and the demand is increased day by day. The traditional process for preparing the silicomethane with small scale has complex operation, high cost and low production efficiency, heat released form reaction can not be dispersed in time to cause lower process safety, silane and ammonia leak is generated in the process of material flow, and the environment is polluted. The invention prepares silicomethane gas through purification and carries out comprehensive recycling on byproducts generated in the production so as to realize true circulation clean production. The silicomethane low-temperature production and byproduct comprehensive recycling process realizes continuous production, and has the advantages of high degree of automation, cleanness, no leakage, safety, reliability, convenient operation and simple maintenance.

Description

technical field [0001] The invention belongs to the technical field of polysilicon, and in particular relates to a process for low-temperature production of silane and comprehensive recovery of by-products. Background technique [0002] High-purity special gas silane (SiH4) is widely used in the electronics industry, solar cells, mobile communications, car navigation, aerospace, military industry, etc. At present, my country's industrialization can only produce 3N-4N silane. In many important fields such as the electronics industry, solar cells, aerospace and other fields, most of the high-purity silane gas with a purity of 6N and above can only be imported. Due to technical reasons, the existing silane production process mostly adopts small-scale intermittent operation, which is complex in operation, high in cost and low in production efficiency, and cannot meet the needs of industrial-scale production; there are also some silane production processes, although they also La...

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Problems solved by technology

Due to technical reasons, the existing silane production process mostly adopts small-scale intermittent operation, which is complex in operation, high in cost and low in production efficiency, and cannot meet the needs of industrial-scale production; there are also some silane production processes, although they also Larger tank reactors are used to produce silane on a large scale, but because the reaction is carried out in a liquid ammonia environment at -40°C, and the reaction is exothermic, the excess heat cannot be removed in time, resulting in low process safety performance; in addition , because the reaction is a continuous operation, the leakage of silane and ammonia is often caused during the feeding process of raw materials, which not only pollutes the environment but also brings safety hazards to production. Finally, although some silane production processes also use electronic control technology, automatic correlation The degree is not high, especially when there is an emergency power failure, there will be pressure in the kettle and the ammonia cooler, which will bring great hidden dangers to production safety

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