Purification method and purification apparatus for off-gas

Patent metadata

Field	Value
Publication number	US-10016724-B2
Application number	US-201515113110-A
Country	US
Kind code	B2
Filing date	Jan 19, 2015
Priority date	Jan 24, 2014
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

The present invention relates to a purification method and a purification apparatus for off-gas. More specifically, the present invention relates to a purification method and a purification apparatus for off-gas, capable of lowering the concentration of hydrogen chloride and separating high-purity hydrogen from the off-gas, which is discharged after performing a polysilicon deposition process by a chemical vapor deposition reaction.

First claim

What is claimed is:

1. A method of purifying an off-gas, the method comprising,
separating the off-gas, which is discharged after performing a polysilicon deposition process by a chemical vapor deposition (CVD) reaction, into a non-condensed phase stream and a condensed phase stream, wherein the off-gas is condensed to greater than −30° C. and less than 10° C. to separate into the non-condensed phase stream and the condensed phase stream;
passing the non-condensed phase stream through a first catalytic reactor to lower the concentration of hydrogen chloride; and
separating a chlorosilane-based compound of the condensed phase stream according to the boiling point.

2. The method of purifying an off-gas according to claim 1 , wherein the first catalytic reactor includes one or more catalysts selected from the group consisting of an ion exchange resin and a transition metal.

3. The method of purifying an off-gas according to claim 2 , wherein the ion exchange resin catalyst includes a cyclic amine compound, a styrene-based polymer containing an amine group, a styrene-divinyl benzene-based polymer containing an amine group, an acrylic polymer containing an amine group, or mixtures thereof.

4. The method of purifying an off-gas according to claim 1 , wherein the off-gas includes hydrogen chloride (HCl), hydrogen (H 2 ), and chlorosilane-based compounds.

5. The method of purifying an off-gas according to claim 1 , wherein the content of hydrogen chloride occupied in the non-condensed phase steam which has been passed through the catalytic reactor is reduced to about 80 mol % or more, with respect to the content before passing through the catalytic reactor.

6. The method of purifying an off-gas according to claim 1 , wherein the non-condensed phase steam is converted into trichlorosilane and silicon tetrachloride by passing through the first catalytic reactor.

7. The method of purifying an off-gas according to claim 1 , further comprising a step of separating the non-condensed phase stream passed through the first catalytic reactor into hydrogen stream and chlorosilane-based stream.

8. The method of purifying an off-gas according to claim 7 , wherein the separated chlorosilane-based stream is joined with the condensed phase stream and transferred to a step of separating the chlorosilane-based compound of the condensed phase stream according to the boiling point.

9. The method of purifying an off-gas according to claim 1 , further comprising a step of lowering the concentration of hydrogen chloride contained in the condensed phase stream, before performing a step of separating the chlorosilane-based compound of the condensed phase stream according to the boiling point.

10. The method of purifying an off-gas according to claim 9 , wherein the step of lowering the concentration of hydrogen chloride contained in the condensed phase stream is performed by distilling the condensed phase stream or by passing through a second catalytic reactor.

11. The method of purifying an off-gas according to claim 10 , wherein the first catalytic reactor includes one or more catalysts selected from the group consisting of an ion exchange resin and a transition metal.

Assignees

• Hanwha Chemical Corp

Inventors

• Kim Sang Ah
• Park Jea Sung
• Lee Won Ik
• Kim Gil Ho
• Kim Bo Kyung
• Ahn Gui Ryong

Classifications

• C23C16/24

  Deposition of silicon only · CPC title

• B01D53/8659 Primary

  Removing halogens or halogen compounds · CPC title

• B01D2258/0216

  from CVD treatment or semi-conductor manufacturing · CPC title

• B01D2257/2045

  Hydrochloric acid · CPC title

• C23C16/4412

  Details relating to the exhausts, e.g. pumps, filters, scrubbers, particle traps · CPC title