Patent ID: 8187361

Claim:
A method for recycling an effluent gas generated during polysilicon or silane production, comprising the steps of: directing the effluent gas comprising at least SiHCl 3 , SiCl 4 , HCl, and H 2 from a purification unit, a STC converter, and/or a polysilicon deposition reactor to a condenser to produce a condensate and a non-condensate, the condensate comprising predominantly SiHCl 3 and SiCl 4 , the non-condensate comprising a major amount of H 2 , a minor amount of chlorosilanes comprising SiHCl 3 , SiCl 4 , and a minor amount of HCl; directing the non-condensate to a compressor and then to a gas separation unit comprising at least one gas separation membrane; directing a sweep gas comprising SiHCl 3 or SiCl 4 to a permeate side of the membrane; recovering a recycle gas from the permeate side, the recycle gas comprising H 2 permeated through the membrane from the non-condensate and SiHCl 3 or SiCl 4 from the sweep gas; and directing the recycle gas to a hydrochlorination reactor, the STC converter, and/or the deposition reactor.