Method and apparatus for production of electronic grade hydrogen gas

Abstract

The present invention discloses a method and an apparatus for the production of electronic grade hydrogen gas, and the method comprises the following steps: (1) tail gas of the production of polysilicon is treated to obtain hydrogen gas with a purity of 99.808-99.945%, and the hydrogen gas with the purity of 99.808-99.945% is adsorbed by an activated carbon adsorption agent; and (2) an aqueous solution containing sodium hydroxide and potassium permanganate is used for rinsing to obtain the electronic grade hydrogen gas. The electronic grade hydrogen gas with a purity of 99.9999% can be obtained, hydrogen chloride, boron trichloride, phosphoric chloride, phosphorane, CH3BCl2, (CH3) 2PH other impurities in the hydrogen gas with the purity of 99.808-99.945% obtained by treatment of the tail gas of the production of polysilicon can be completely removed, hydrogen purification efficiency is high, and waste hydrogen gas, in the production of polysilicon, which cannot produce high-purity polysilicon is purified for turning the waste into the high-value electronic grade hydrogen gas.

Description

technical field [0001] The invention belongs to the technical field of polysilicon production, and in particular relates to a method and device for producing electronic-grade hydrogen. Background technique [0002] After decades of research and production practice, the production of polysilicon by fluidized bed method and metallurgical method can only barely meet the requirements of solar-grade polysilicon, and it is difficult to produce high-purity polysilicon. In the production of electronic grade polysilicon, SiCl 4 The cost of producing electronic grade polysilicon is higher, and the rest is SiH 4 Production of Electronic Grade Polysilicon and SiHCl by Decomposition 3 Electronic-grade polysilicon is produced by electronic-grade polysilicon. Considering production costs and benefits, most polysilicon companies in the world currently use SiHCl 3 production of electronic grade polysilicon. [0003] Hydrogen is SiHCl 3 It is an important raw material for the production ...

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Problems solved by technology

[0004] At present, SiHCl at home and abroad 3 Electronic-grade polysilicon is produced by the method, which basically adopts multi-stage cooling of polysilicon tail gas, absorption and separation of hydrogen chloride and chlorosilane, and then recovers hydrogen, and returns the recovered hydrogen to SiHCl 3 Hydrogen reduction reaction is carried out to produce polysilicon, however, usually the recovered hydrogen contains hydrogen chloride, boron chloride, phosphorus chloride, phosphine, borane, carbon monoxide, carbon dioxide, methane, nitrogen, CH 3 BCl 2 , (CH 3 ) 2 PH, (CH 3 ) 3 CCl and other impurities, these impurities are harmful to the quality of polysilicon, which in turn makes the polysilicon produced by using recycled hydrogen not meet the requirements of electronic grade polysilicon

In the prior art, to purify the hydrogen recovered from the production of polysilicon, a single physical adsorption technology or water is used to purify the hydrogen to recover the hydrogen. These methods of removing impurities cannot completely remove hydrogen chloride, boron chloride, phosphorus chloride, Phosphine, CH 3 BCl 2 , (CH 3 ) 2 PH and other impurities

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