US3880983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flue gas desulfurization with ammonium sulfite-bisulfite solution
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1971-11-19
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Granted: 1975-04-29
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Expires: 1991-11-19
Abstract
Abstract Flue gas is desulfurized by absorption in an aqueous ammonium sulfite-ammonium bisulfite solution. Any ammonia which is picked up in the flue gas during desulfurization is removed by scrubbing the flue gas with wash water. Sulfur dioxide is recovered from the absorber effluent solution by acidifying a portion thereof with ammonium bisulfate, crystallizing and decomposing the ammonium sulfate thus formed, reacting the ammonia formed during decomposition with a second portion of the absorber effluent solution to form fresh ammonium sulfite-ammonium bisulfite solution.
Inventors
- 👤 Jr Albert B Welty
- 👤 Jr Lindsay I Griffin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:21
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/48; C01B17/50; C01B17/60; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/501
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
152 words
A PROCESS FOR REMOVING SULFUR DIOXIDE FROM FLUE GAS WHICH COMPRISES: A. INTRODUCING A STREAM OF FLUE GAS CONTAINING SULFUR DIOXIDE INTO AN ABSORPTION ZONE; B. CONTACTING SAID FLUE GAS IN SAID ABSORPTION ZONE WITH AN AQUEOUS SOLUTION OF AMMONIUM SULFITE AND AMMONIUM BISULFITE INTIALLY HAVING A PH FROM ABOUT 6 TO ABOUT 7 IN ORDER TO REMOVE SULFUR DIOXIDE THEREFROM; C. PASSING DEFULFURIZED FLUE GAS FROM SAID ADSORPTION ZONE TO A WASH ZONE; D. CONTACTING SAID DESULFURIZED FLUE GAS WITH WASH WATER IN SAID WASH ZONE IN ORDER TO REMOVE AMMONIA THEREFROM; E. DISCHARGING A FLUE GAS STREAM OF SUBSTANTIALLY REDUCED SULFUR DIOXIDE CONTENT FROM SAID WASH ZONE; F. WITHDRAWING AN AQUEOUS ABSORBER EFFLUENT SOLUTION CONTAINING AMMONIUM BISULFITE AS THE PRINCIPAL SOLUTE FROM SAID ABSORPTION ZONE; G DIVIDING SAID ABSORBER EFFLUENT SOLUTION INTO TWO PORTIONS AND ACIDIFYING THE FIRST PORTION WITH AMMONIUM BISULFATE, THEREBY LIBERATING SULFUR DIOXIDE AND FORMING AMMONIUM SULFATE;
Claim 2
Dependent Claim
152 words
A PROCESS FOR REMOVING SULFUR DIOXIDE FROM FLUE GAS WHICH COMPRISES: A. INTRODUCING A STREAM OF FLUE GAS CONTAINING SULFUR DIOXIDE INTO AN ABSORPTION ZONE; B. CONTACTING SAID FLUE GAS IN SAID ABSORPTION ZONE WITH AN AQUEOUS SOLUTION OF AMMONIUM SULFITE AND AMMONIUM BISULFITE INTIALLY HAVING A PH FROM ABOUT 6 TO ABOUT 7 IN ORDER TO REMOVE SULFUR DIOXIDE THEREFROM; C. PASSING DEFULFURIZED FLUE GAS FROM SAID ADSORPTION ZONE TO A WASH ZONE; D. CONTACTING SAID DESULFURIZED FLUE GAS WITH WASH WATER IN SAID WASH ZONE IN ORDER TO REMOVE AMMONIA THEREFROM; E. DISCHARGING A FLUE GAS STREAM OF SUBSTANTIALLY REDUCED SULFUR DIOXIDE CONTENT FROM SAID WASH ZONE; F. WITHDRAWING AN AQUEOUS ABSORBER EFFLUENT SOLUTION CONTAINING AMMONIUM BISULFITE AS THE PRINCIPAL SOLUTE FROM SAID ABSORPTION ZONE; G DIVIDING SAID ABSORBER EFFLUENT SOLUTION INTO TWO PORTIONS AND ACIDIFYING THE FIRST PORTION WITH AMMONIUM BISULFATE, THEREBY LIBERATING SULFUR DIOXIDE AND FORMING AMMONIUM SULFATE;
Claim 3
Dependent Claim
28 words
A process according to claim 1 in which said stream of flue gas is cooled by quenching with an aqueous medium prior to introduction into said absorption zone.
Claim 4
Dependent Claim
20 words
A process according to claim 2 in which the effluent wash water from said wash zone is the aqueous medium.
Claim 5
Dependent Claim
35 words
A process according to claim 1 in which the effluent wash water from said wash zone is introduced into said absorption zone and combined therein with said aqueous solution of ammonium sulfite and ammonium bisulfite.
Claim 6
Dependent Claim
32 words
A process according to claim 1 in which the aqueous absorber effluent solution is introduced into a storage tank, and is withdrawn from said storage tank at a substantially constant flow rate.
Claim 7
Dependent Claim
36 words
A process according to claim 1 in which at least a portion of the ammonium sulfate formed in step (g) is in aqueous solution and is crystallized from said solution by evaporating the water content thereof.
Claim 8
Dependent Claim
26 words
A process according to claim 6 in which the water evaporated from said solution is condensed and used as the wash water in said wash zone.
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) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |