Method for purification of off-gas and device for the same

Patent metadata

Field	Value
Publication number	US-2016166986-A1
Application number	US-201414905983-A
Country	US
Kind code	A1
Filing date	Aug 12, 2014
Priority date	Aug 28, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

This disclosure relates to a method for purification of off-gas and a device for the same. More particularly, this disclosure relates to a method for purification of off-gas that removes hydrogen chloride from the off-gas discharged after conducting a polysilicon deposition process by chemical vapor deposition, and can separate hydrogen of high purity, and a device for the same.

First claim

1 . A method for purifying off-gas comprising
preparing a carbon support on which a transition metal catalyst is supported; and passing off-gas comprising hydrogen chloride (HCl), hydrogen (H 2 ), and chlorosilane compounds through the carbon support to remove hydrogen chloride.

2 . The method for purifying off-gas according to claim 1 , wherein the transition metal is at least one selected from the group consisting of platinum, palladium, ruthenium, nickel, iridium, rhodium, and compounds thereof.

3 . The method for purifying off-gas according to claim 1 , wherein the carbon support is selected from the group consisting of activated carbon, carbon nanotubes, carbon nanoribbons, carbon nanowires, porous carbon, carbon powder, and carbon black.

4 . The method for purifying off-gas according to claim 1 , wherein the transition meal catalyst is supported in the content of 0.01 to 20 wt %, based on total weight of the carbon support.

5 . The method for purifying off-gas according to claim 1 , wherein the off-gas is gas discharged after conducting a polysilicon deposition process by chemical vapor deposition (CVD).

6 . The method for purifying off-gas according to claim 1 , wherein the off-gas comprises 50 mol % or more of hydrogen, based on the total off-gas.

7 . The method for purifying off-gas according to claim 1 , wherein the chlorosilane compound includes dichlorosilane (SiH 2 Cl 2 ), trichlorosilane (SiHCl 3 ), and silicon tetrachloride (SiCl 4 ).

8 . The method for purifying off-gas according to claim 1 , wherein the content of the hydrogen chloride in the off-gas that has passed through the carbon support is decreased 80% or more, based on the mole number, compared to that before passing through the carbon support.

9 . The method for purifying off-gas according to claim 1 , wherein the step of passing the off-gas through the transition metal catalyst-supported carbon support is conducted under conditions of 20 to 500° C. and 1 to 30 bar.

10 . The method for purifying off-gas according to claim 1 , wherein as the off-gas passes through the transition metal catalyst-supported carbon support, hydrogen chloride is converted into trichlorosilane and silicon tetrachloride.

11 . The method for purifying off-gas according to claim 1 , further comprising separating hydrogen and chlorosilane compounds from the off-gas that has passed through the carbon support.

12 . The method for purifying off-gas according to claim 11 , wherein the step of separating hydrogen and chlorosilane compounds from the off-gas that has passed through the carbon support is conducted by a separation membrane process, a distillation process, a gas liquid separation process, or combinations thereof.

13 . A device for purification of off-gas comprising
a catalytic reactor that comprises a transition metal catalyst-supported carbon support, and passes off-gas comprising hydrogen chloride (HCl), hydrogen (H 2 ), and chlorosilane compounds to remove hydrogen chloride; and a separator for separating hydrogen and chlorosilane compounds from the off-gas that has passed through the catalytic reactor.

14 . The device for purification off-gas according to claim 13 , wherein the separator includes at least one selected from the group consisting of a distillation apparatus, a separation membrane apparatus, and a gas liquid separation apparatus.

Assignees

• Hanwha Chemical Corp

Inventors

• Kim Gil Ho
• Lee Won Ik
• Ahn Gui Ryong
• Kim Bo Kyung

Classifications

• B01D2256/26

  Halogens or halogen compounds · CPC title

• B01D2255/102

  Platinum group metals · CPC title

• B01J23/755

  Nickel · CPC title

• B01D2258/0216

  from CVD treatment or semi-conductor manufacturing · CPC title

• B01J21/18

  Carbon · CPC title