Patent ID: 8679228
Filing Date: 2014-03-25
Classification: B01D,C01B

Abstract:
1. A method of reusing hydrogen in an exhaust purge gas, comprising: (1) a hydrogen chloride adsorption step of adsorbing the hydrogen chloride by passing, through an active carbon layer, the exhaust gas discharged from a step of producing polysilicon by reacting hydrogen with a trichlorosilane; (2) a hydrogen chloride desorption step of desorbing the adsorbed hydrogen chloride by passing a hydrogen gas as the purge gas through the active carbon layer that has adsorbed and held the hydrogen chloride; (3) a hydrogen recovery step of obtaining the hydrogen gas from which the hydrogen chloride has been removed by bringing, into contact with a hydrogen chloride-absorbing solution, the exhaust purge gas that contains hydrogen and the hydrogen chloride desorbed in said hydrogen chloride desorption step; and (4) a hydrogen feed step of compressing the hydrogen gas recovered in said hydrogen recovery step and feeding the hydrogen gas as a hydrogen source for other steps, wherein said method further comprises a water washing step of washing with water the hydrogen gas recovered in the hydrogen recovery step prior to the hydrogen feed step, and a step of bringing the hydrogen gas washed with water in the water washing step into contact with a silane-trapping agent prior to the hydrogen feed step or during the compression in the hydrogen feed step and, thereafter, separating, from the hydrogen gas, the silane-trapping agent that accompanies the hydrogen gas.