Patent US3928548A successfully refreshed from Google Patents.
US3928548A
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Process for purifying a sulfurous anhydride containing gas and producing elemental sulfur
Assignee: IFP Energies nouvelles
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Filing: 1973-09-17
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Granted: 1975-12-23
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Expires: 1993-09-17
Abstract
Abstract Process for simultaneously purifying a sulfurous anhydride and oxygen containing gas and recovering produced sulfur comprising a first stage of absorbing the SO2 of said gas in a solution of urea, thiourea or alkali metal or ammonium salt of a carboxylic acid or of an alkyl-, cycloalkyl- or aryl-phosphoric acid in an inert solvent and a second stage of producing sulfur and regenerating said solution by contacting it with a H2S containing gas.
Inventors
- 👤 Andre Deschamps
- 👤 Philippe Renault
- 👤 Claude Dezael
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:24
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/14; B01D53/1456; B01D53/1468; B01D53/1418; B01D53/1425; B01D53/1481; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/507; C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; C01B17/05; B01D2252/00; B01D2252/20; B01D2252/202; B01D2252/2023; B01D2252/2026; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
137 words
A PROCESS FOR PURIFYING A GAS CONTAINING SULFUROUS ANHYDRIDE AND 0.5-10% BY VOLUME OF OXYGEN, WHILE PRODUCING ELEMENTAL SULFUR, SAID PROCESS COMPRISING: IN A FIRST STAGE CONTACTING THE GAS AT 20*-130*C WITH AN ABSORBING SOLUTION OF UREA, THIOUREA OR AN ALKALI METAL OR AMMONIUM SALT OF BENZOIC ACID OR OF AN ALKYL-, CYCLOALKYL- OR ARYL-PHOSPHORIC ACID IN A MIXTURE OF WATER AND POLYETHYLENE GLYCOL HAVING A MOLECULAR WEIGHT OF ABOUT 200-600, SO AS TO ABSORB THE SULFUROUS ANHYDRIDE IN SAID ABSORBING SOLUTION, SEPARATING RESULTANT SULFUROUS ANHYDRIDE CONTANING ABSORBING SOLUTION FROM THE GAS CONTAINING 0.5-10% BY VOLUME OF OXYGEN, AND, IN A SECOND STAGE CONTACTING RESULTANT SEPARATED SOLUTION AT 20*-130*C WITH A GAS CONTAINING HYDROGEN SULFIDE, SUBSTANTIALLY IN THE ABSENCE OF OXYGEN, SO AS TO PRODUCE SULFUR AND TO REGENERATE THE ABSORBING SOLUTION USED IN THE FIRST STAGE.
Claim 2
Dependent Claim
137 words
A PROCESS FOR PURIFYING A GAS CONTAINING SULFUROUS ANHYDRIDE AND 0.5-10% BY VOLUME OF OXYGEN, WHILE PRODUCING ELEMENTAL SULFUR, SAID PROCESS COMPRISING: IN A FIRST STAGE CONTACTING THE GAS AT 20*-130*C WITH AN ABSORBING SOLUTION OF UREA, THIOUREA OR AN ALKALI METAL OR AMMONIUM SALT OF BENZOIC ACID OR OF AN ALKYL-, CYCLOALKYL- OR ARYL-PHOSPHORIC ACID IN A MIXTURE OF WATER AND POLYETHYLENE GLYCOL HAVING A MOLECULAR WEIGHT OF ABOUT 200-600, SO AS TO ABSORB THE SULFUROUS ANHYDRIDE IN SAID ABSORBING SOLUTION, SEPARATING RESULTANT SULFUROUS ANHYDRIDE CONTANING ABSORBING SOLUTION FROM THE GAS CONTAINING 0.5-10% BY VOLUME OF OXYGEN, AND, IN A SECOND STAGE CONTACTING RESULTANT SEPARATED SOLUTION AT 20*-130*C WITH A GAS CONTAINING HYDROGEN SULFIDE, SUBSTANTIALLY IN THE ABSENCE OF OXYGEN, SO AS TO PRODUCE SULFUR AND TO REGENERATE THE ABSORBING SOLUTION USED IN THE FIRST STAGE.
Claim 3
Dependent Claim
14 words
A process according to claim 1, in which the absorbing solution also containing water.
Claim 4
Dependent Claim
28 words
A process according to claim 1, in which the acid used for producing the salt has at least one acid function whose pKa is from 2.5 to 6.
Claim 5
Dependent Claim
28 words
A process according to claim 1, in which the molar ratio of the constituents, base/acid, which participate in the composition of the salt, is from 0.1 to 2.
Claim 6
Dependent Claim
28 words
A process according to claim 1, in which the molar ratio of the constituents, base/acid, which participate in the composition of the salt, is from 0.2 to 0.9.
Claim 7
Dependent Claim
14 words
A process according to claim 1, in which the solution is an urea solution.
Claim 8
Dependent Claim
17 words
A process according to claim 1, wherein each stage of the process is conducted at 40*-90* C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |