US3895101A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the treatment of waste gas from claus process
Assignee: Tsukishima Kankyo Engineering Ltd
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Filing: 1974-06-07
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Granted: 1975-07-15
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Expires: 1994-06-07
Abstract
Abstract The sulfur component of the waste gas (which is called tail gas) which issues from the Claus process is effectively recovered and prevented from being released into the atmosphere by a method which comprises oxidizing by combustion the waste gas (hereinafter referred to as ''''tail gas'''') for thereby converting the whole sulfur component into SO2, thereafter mixing the resulting gas with a reducing combustion gas for thereby lowering the residual oxygen content of said tail gas to substantial absence, subsequently cooling the resulting gas containing substantially no oxygen and then introducing the cooled gas into a liquid capable of absorbing SO2, heating the resulting SO2absorbed liquid and recovering the SO2 consequently liberated from the liquid, and circulating the recovered SO2 to the Claus process.
Inventors
- 👤 Hidemasa Tsuruta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:44
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; C01B17/0404; C01B17/0456; C01B17/48; C01B17/50; C01B17/60
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
142 words
A METHOD FOR THE TREATMENT OF THE TAIL GAS FORMED IN THE CLAUS PROCESS, CHARACTERIZED BY OXIDIZING BY COMBUSTION THE TAIL GAS THEREBY CONVERTING THE WHOLE SULFUR COMPONENT THEREOF INTO SULFUROUS ACID GAS (SO2), THEREAFTER MIXING THE RESULTING GAS WITH A REDUCING COMBUSTION GAS CONTAINING CARBON MONOXIDE AND HYDROGEN FOR THEREBY LOWERING THE RESIDUAL OXYGEN CONTENT OF SAID TAIL GAS TO SUBSTANTIAL ABSENCE SUBSEQUENTLY COOLING THE RESULTING GAS CONTAINING SUBSTANTIALLY NO OXYGEN IN A NEUTRAL TO REDUCTIVE ATMOSPHERE, THEN INTRODUCING THE COOLED GAS INTO A LIQUID CAPABLE OF ABSORBING SO2 FOR THEREBY CAUSING THE SULFUROUS ACID GAS PRESENT IN SAID TAIL GAS TO BE ABSORBED IN SAID LIQUID, HEATING THE SULFUROUS ACID GASABSORBED LIQUID OR THEREBY CAUSING THE LIQUID TO LIBERATE THE SULFUROUS ACID GAS, THEN RECOVERING THE LIBERATED SULFUROUS ACID GAS AND CIRCULATING THE RECOVERED GAS TO THE AFOREMENTIONED CLAUS PROCESS.
Claim 2
Independent Claim
142 words
A METHOD FOR THE TREATMENT OF THE TAIL GAS FORMED IN THE CLAUS PROCESS, CHARACTERIZED BY OXIDIZING BY COMBUSTION THE TAIL GAS THEREBY CONVERTING THE WHOLE SULFUR COMPONENT THEREOF INTO SULFUROUS ACID GAS (SO2), THEREAFTER MIXING THE RESULTING GAS WITH A REDUCING COMBUSTION GAS CONTAINING CARBON MONOXIDE AND HYDROGEN FOR THEREBY LOWERING THE RESIDUAL OXYGEN CONTENT OF SAID TAIL GAS TO SUBSTANTIAL ABSENCE SUBSEQUENTLY COOLING THE RESULTING GAS CONTAINING SUBSTANTIALLY NO OXYGEN IN A NEUTRAL TO REDUCTIVE ATMOSPHERE, THEN INTRODUCING THE COOLED GAS INTO A LIQUID CAPABLE OF ABSORBING SO2 FOR THEREBY CAUSING THE SULFUROUS ACID GAS PRESENT IN SAID TAIL GAS TO BE ABSORBED IN SAID LIQUID, HEATING THE SULFUROUS ACID GASABSORBED LIQUID OR THEREBY CAUSING THE LIQUID TO LIBERATE THE SULFUROUS ACID GAS, THEN RECOVERING THE LIBERATED SULFUROUS ACID GAS AND CIRCULATING THE RECOVERED GAS TO THE AFOREMENTIONED CLAUS PROCESS.
Claim 3
Dependent Claim
35 words
The method of claim 1, wherein said tail gas is oxidized by combustion together with an auxiliary fuel under conditions of not more than 1.50 of air ratio and not less than 600*C of temperature.
Claim 4
Dependent Claim
21 words
The method of claim 1, wherein said tail gas is oxidized by combustion while in the presence of ammonium sulfate solution.
Claim 5
Dependent Claim
26 words
The method of claim 1, wherein said liquid capable of absorbing sulfurous acid gas is an aqueous solution containing ammonium sulfite as the principal active component.
Claim 6
Dependent Claim
64 words
The method of claim 4, wherein the liquid containing acidic ammonium sulfite which is obtained by having the aforementioned aqueous solution absorb the sulfurous acid gas is heated to cause liberation of sulfurous acid gas therefrom and the aqueous solution containing ammonium sulfite which is formed in consequence of said liberation is utilized cyclically as the liquid for the absorption of sulfurous acid gas.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |