Purification method and purification apparatus for off-gas

Patent metadata

Field	Value
Publication number	US-2017007962-A1
Application number	US-201515113110-A
Country	US
Kind code	A1
Filing date	Jan 19, 2015
Priority date	Jan 24, 2014
Publication date	Jan 12, 2017
Grant date	—

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

1 - 18 . (canceled)

19 . A purification method for off-gas which comprises the steps of:
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; 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.

20 . The purification method for off-gas according to claim 19 , wherein the catalyst used in the first catalytic reactor includes one or more selected from the group consisting of an ion exchange resin and a transition metal.

21 . The purification apparatus for off-gas according to claim 20 , 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.

22 . The purification method for off-gas according to claim 19 , wherein the off-gas includes hydrogen chloride (HCl), hydrogen (H 2 ), and chlorosilane-based compounds.

23 . The purification method for off-gas according to claim 19 , 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.

24 . The purification method for off-gas according to claim 19 , 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.

25 . The purification method for off-gas according to claim 19 , wherein the non-condensed phase steam is converted into trichlorosilane and silicon tetrachloride by passing through the first catalytic reactor.

26 . The purification method for off-gas according to claim 19 , further comprising a step of separating the non-condensed phase stream passed through the first catalytic reactor into hydrogen stream and chlorosilane-based stream.

27 . The purification method for off-gas according to claim 26 , 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.

28 . The purification method for off-gas according to claim 19 , wherein before performing a step of separating the chlorosilane-based compound of the condensed phase stream according to the boiling point, a step of lowering the concentration of hydrogen chloride contained in the condensed phase stream is further comprised.

29 . The purification method for off-gas according to claim 28 , 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 pasting through the second catalytic reactor.

30 . The purification method for off-gas according to claim 29 , wherein the catalyst used in the first catalytic reactor includes one or more 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

• B01D53/8659 Primary

  Removing halogens or halogen compounds · CPC title

• C01B2203/0465

  Composition of the impurity · CPC title

• C01B3/50

  Separation of hydrogen or hydrogen-containing gases from gaseous mixtures, e.g. purification · CPC title

• B01D2257/2045

  Hydrochloric acid · CPC title

• B01D2258/0216

  from CVD treatment or semi-conductor manufacturing · CPC title