EP0294142A2
Expired / Lapsed
EP
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Method of cleaning exhaust gases
Assignee: Japan Pionics Ltd
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Filing: 1988-05-31
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Granted: —
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Expires: 2008-05-31
Abstract
Abstract In a method of cleaning an exhaust gas comprising a base gas containing toxic arsine, phosphine, diborane and/or hydrogen selenide, the exhaust gas is contacted with a molded cleaning agent consisting of (1) cupric oxide, (2) manganese dioxide, and (3) at least one metal oxide selected from silicon oxide, aluminum oxide and zinc oxide and having a density of from 0.6 to 1.5 g/ml, said composition having a metal atomic ratio M/(M+Cu+Mn) in the range of 0.02 to 0.70 and a metal atomic ratio Cu/(Cu+Mn) in the range of 0.1 to 0.9, wherein Cu, Mn and M represent respectively a number of gram atoms of copper, of manganese, and total of silicon, aluminium and/or zinc. The cleaning agent is used as pellets or particles usually in a fixed bed, in a layer (5) in a column (3), preferably with a layer (6) of a color-changing toxic component detecting agent. The method is effective in removing toxic components in the manufacture of semi-conductors, even at temperatures below 10°C.
Inventors
- 👤 Koichi Kitahara
- 👤 Takashi Shimada
- 👤 Noboru Akita
- 👤 Tadashi Hiramoto
- 👤 Kohhei Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 04:58
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; C; C01; C01B; C01B23/00; B01D53/46; B01D53/74; B01D53/86; B01D53/8671; C01B21/00; C01B21/04; C01B21/0405; C01B21/0411; C01B21/0427; C01B3/00; C01B3/50; C01B3/56; C01B2203/00; C01B2203/04; C01B2203/042; C01B2203/0465; C01B2210/00; C01B2210/0043
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
159 words
A method of cleaning an exhaust gas comprising a base gas and at least one toxic component selected from the group consisting of arsine, phosphine, diborane and hydrogen selenide, which comprises contacting the exhaust gas with a molded low-temperature type cleaning agent having a composition consisting essentially of (1) cupric oxide, (2) manganese dioxide, and (3) at least one metal oxide selected from silicon oxide, aluminum oxide and zinc oxide and having a density of from 0.6 to 1.5 g/ml, said composition having a metal atomic ratio M/(M + Cu + Mn) in the range of from 0.02 to 0.70 and a metal atomic ratio Cu/(Cu + Mn) in the range of from 0.1 to 0.9, wherein Cu represents a number of gram atom s of copper; Mn represents a number of gram atoms of manganese; and M represents a total number of gram atoms of silicon, aluminum and/or zinc, to remove the toxic component from the exhaust gas.
Claim 2
Independent Claim
159 words
A method of cleaning an exhaust gas comprising a base gas and at least one toxic component selected from the group consisting of arsine, phosphine, diborane and hydrogen selenide, which comprises contacting the exhaust gas with a molded low-temperature type cleaning agent having a composition consisting essentially of (1) cupric oxide, (2) manganese dioxide, and (3) at least one metal oxide selected from silicon oxide, aluminum oxide and zinc oxide and having a density of from 0.6 to 1.5 g/ml, said composition having a metal atomic ratio M/(M + Cu + Mn) in the range of from 0.02 to 0.70 and a metal atomic ratio Cu/(Cu + Mn) in the range of from 0.1 to 0.9, wherein Cu represents a number of gram atom s of copper; Mn represents a number of gram atoms of manganese; and M represents a total number of gram atoms of silicon, aluminum and/or zinc, to remove the toxic component from the exhaust gas.
Claim 3
Dependent Claim
44 words
A method as claimed in Claim 1, wherein said composition has a metal atomic ratio M/(M + Cu + Mn) in the range of from 0.03 to 0.55 and a metal atomic ratio Cu/(Cu + Mn) in the range of from 0.2 to 0.8.
Claim 4
Dependent Claim
24 words
A method as claimed in Claim 1 or 2, wherein said base gas of the exhaust gas is selected from nitrogen, hydrogen and helium.
Claim 5
Dependent Claim
30 words
A method as claimed in Claim 1, 2 or 3, wherein said contacting is carried out by passing the exhaust gas through a cleaning column packed with said cleaning agent.
Claim 6
Dependent Claim
22 words
A method as claimed in Claim 4, wherein said contacting is carried out at an inlet gas temperature between -20°C and 40°C.
Claim 7
Dependent Claim
29 words
A method as claimed in Claim 4 or 5, wherein said cleaning column is further packed with a detecting agent by which breakthrough of the cleaning column is detected.
Claim 8
Independent Claim
111 words
A method as claimed in any preceding claim wherein the method further includes pretreatment of the exhaust gas containing a toxic component with a high capacity type cleaning agent comprising a molded composition consisting essentially of (4) cupric oxide and (5) at least one metal oxide selected from the group consisting of silicon dioxide, aluminum oxide and zinc oxide and having a density of from 1.5 to 3.5 g/ml, said composition having a metal atomic ratio M/(M + Cu) in the range of from 0.02 to 0.70, wherein M represents a total number of gram atom of silicon, aluminum and/or zinc, and Cu represents a number of gram atom of copper.
Claim 9
Dependent Claim
47 words
A method as claimed in Claim 7, wherein said contacting is carried out by passing the exhaust gas through a cleaning column packed with said high capacity type cleaning agent at the inlet side thereof and with said low-temperature type cleaning agent at the outlet side thereof.
References Cited (Backward Citations)
No citation records indexed.
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