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US4009244A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for removing oxides of nitrogen and sulfur from exhaust gases

Assignee: Mitsubishi Heavy Industries Ltd
•
Filing: 1975-04-03
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Granted: 1977-02-22
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Expires: 1995-04-03
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Abstract

Abstract The present invention relates to a process for wet-treating an exhaust gas which comprises simultaneously removing a nitrogen oxide (NO x ) and a sulfur oxide (SO x ) from an exhaust gas containing these oxides by treating exhaust gas containing oxides of nitrogen and sulfur with a lime or limestone slurry containing alkali metal or alkaline earth metal iodide.

Inventors

  • 👤 Masumi Atsukawa
  • 👤 Naoharu Shinoda
  • 👤 Kenji Inoue

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 23:04
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/60

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 59 words
A process for removing oxides of nitrogen and of sulfur from exhaust gases, comprising washing exhaust gases containing the oxides of nitrogen and of sulfur with a slurry of lime or limestone, which slurry contains a alkali metal iodide or an alkaline earth metal iodide to convert the nitrogen oxide to nitrogen gas and the sulfur oxide to gypsum.
Claim 2
Dependent Claim 59 words
A process for removing oxides of nitrogen and of sulfur from exhaust gases, comprising washing exhaust gases containing the oxides of nitrogen and of sulfur with a slurry of lime or limestone, which slurry contains a alkali metal iodide or an alkaline earth metal iodide to convert the nitrogen oxide to nitrogen gas and the sulfur oxide to gypsum.
Claim 3
Dependent Claim 36 words
The process of claim 1, which consists essentially of oxidizing the nitrogen oxide to NO 2 in the exhaust gas which contains the oxides of nitrogen and of sulfur, prior to undertaking said step of washing.
Claim 4
Dependent Claim 47 words
The process of claim 1, which includes the further step of extracting the slurry after undertaking said step of washing to separate solid material from the liquid, and recycling the separated liquid which contains said iodide to form a part of the slurry of said washing step.
Claim 5
Dependent Claim 21 words
The process of claim 1, wherein said exhaust gas is cooled to below 90° C, prior to undertaking said washing step.
Claim 6
Dependent Claim 15 words
The process of claim 1, wherein the exhaust gas comprises oxygen, carbon dioxide and nitrogen.

References Cited (Backward Citations)

US2242217A Cited
DE1467124A1 Cited
US3556722A Cited
US3499723A Cited
US3652227A Cited
US3733393A Cited
US3773897A Cited
US3888968A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-02-22 1980-08-23 1981-02-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-02-22 1984-08-23 1985-02-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-02-22 1988-08-23 1989-02-22 $7700.00 Window Closed / Lapsed

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