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US4409192A Expired / Lapsed US ⏱️ 0.0 years remaining

Gas scrubbing methods

Assignee: Veolia WTS USA Inc
•
Filing: 1982-04-26
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Granted: 1983-10-11
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Expires: 2002-04-26
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Abstract

Abstract The present invention is directed to a method of removing sulfur dioxide from flue gases derived from furnaces burning high sulfur content fuels. The method comprises spraying flue gases with an aqueous medium containing (i) a material either dissolved or slurried therein, which material reacts with the sulfur dioxide in the flue gas to produce calcium sulfate and calcium sulfite, and (ii) a composition comprising a substantially linear water-soluble sulfonated polystyrene, and an organo-phosphonic acid derivative having the structural formula (X) 2 N--R--N(X) 2 where R is a lower alkyl of from 1 to 7 carbon atoms, X is hydrogen or the group -- CH 2 PO 3 M 2 , where M is a water-soluble cation, the compound being further characterized in that at least one but preferably all X's are --CH 2 PO 3 M 2 . In certain instances it is desirable to use in conjunction with the invention a water-soluble lignosulfonate.

Inventors

  • 👤 Frederick W. Lichtner
  • 👤 Jean T. Rose

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 15:47
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/501; C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 159 words
In a process for scrubbing flue gases containing sulfur dioxide for the removal thereof which comprises (1) contacting the flue gases with an aqueous medium containing a material which will react with the sulfur dioxide to form either calcium sulfate or calcium sulfite or both; and (2) separating the insoluble either calcium sulfate or calcium sulfite or both from the aqueous medium, the improvement being adding to said aqueous medium prior to contact with the gas from about 0.5 to 300 parts per million of a combination of i. a water soluble sulfonated polystyrene, and ii. a compound having the formula: (X) 2 N--R--N(X) 2 , wherein R is a lower alkylene of from 1 to 7 carbon atoms, X is hydrogen or the group --CH 2 PO 3 M 2 , where M is a water-soluble cation, the compound further characterized in that at least one and preferably all X's are --CH 2 PO 3 M 2 .
Claim 2
Dependent Claim 159 words
In a process for scrubbing flue gases containing sulfur dioxide for the removal thereof which comprises (1) contacting the flue gases with an aqueous medium containing a material which will react with the sulfur dioxide to form either calcium sulfate or calcium sulfite or both; and (2) separating the insoluble either calcium sulfate or calcium sulfite or both from the aqueous medium, the improvement being adding to said aqueous medium prior to contact with the gas from about 0.5 to 300 parts per million of a combination of i. a water soluble sulfonated polystyrene, and ii. a compound having the formula: (X) 2 N--R--N(X) 2 , wherein R is a lower alkylene of from 1 to 7 carbon atoms, X is hydrogen or the group --CH 2 PO 3 M 2 , where M is a water-soluble cation, the compound further characterized in that at least one and preferably all X's are --CH 2 PO 3 M 2 .
Claim 3
Dependent Claim 22 words
A method according to claim 1 wherein the polystyrene and the compound are present in a weight ratio of 1:10 to 10:1.
Claim 4
Dependent Claim 19 words
A method according to claim 2 wherein the compound has the formula: (M.sub.2 O.sub.3 PCH.sub.2).sub.2 --N--(CH.sub.2).sub.6 --N--(CH.sub.2 PO.sub.3 M.sub.2).sub.2.
Claim 5
Dependent Claim 18 words
A method according to claim 3 where the styrene has a molecular weight of from 1,000 to 100,000.
Claim 6
Dependent Claim 20 words
A method according to claim 4 wherein the polystyrene is 90% sulfonated and has a molecular weight of about 70,000.
Claim 7
Dependent Claim 18 words
A method according to claim 1 wherein the material contained in said aqueous medium is lime or limestone.
Claim 8
Dependent Claim 22 words
A method according to claim 6 wherein the polystyrene and the compound are present in a weight ratio of 1:10 to 10:1.
Claim 9
Dependent Claim 19 words
A method according to claim 7 wherein the compound has the formula: (M.sub.2 O.sub.3 PCH.sub.2).sub.2 N--(CH.sub.2).sub.6 --N(CH.sub.2 PO.sub.3 M.sub.2).sub.2.
Claim 10
Dependent Claim 18 words
A method according to claim 8 wherein the polystyrene has a molecular weight of from 1,000 to 100,000.
Claim 11
Dependent Claim 20 words
A method according to claim 9 wherein the polystyrene is 90% sulfonated and has a molecular weight of about 70,000.
Claim 12
Dependent Claim 37 words
A method according to claim 10 wherein the ratio of polystyrene to compound is about 1:1.6 and the combination is added to said aqueous medium in the amount of from about 10 to 15 parts per million.

References Cited (Backward Citations)

US3630937A Cited
US3801699A Cited
US3880620A Cited
US4342733A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-10-10 1987-04-11 1987-10-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-10-10 1991-04-11 1991-10-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-10-10 1995-04-11 1995-10-11 $7700.00 Window Closed / Lapsed

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