US3855386A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalytic fused salt extraction process for removal of sulfur oxides from flue or other gases
Assignee: Battelle Memorial Institute Inc
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Filing: 1972-12-04
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Granted: 1974-12-17
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Expires: 1992-12-04
Abstract
Abstract A continuous catalytic fused salt extraction process is described for removing sulfur oxides from gaseous streams. The gaseous stream is contacted with a molten liquid potassium sulfate salt mixture at a temperature below 500* C. having dissolved V2O5 to catalytically oxidize sulfur dioxide to sulfur trioxide and molten potassium normal sulfate to solvate the sulfur trioxide to remove the sulfur trioxide from the gaseous stream. A portion of the sulfur trioxide loaded salt mixture is then placed in an electrolytic cell and with an electrical potential applied between an anode and a cathode to fume the SO3 solute and form a high purity offgas of SO3 and regenerate the molten potassium normal sulfate. The evolved SO3 may be used directly to yield a variety of useful sulfur by-products including liquid sulfur trioxide, sulfuric acids and oleums of any concentrations, liquid sulfur dioxide and elemental sulfur.
Inventors
- 👤 R Moore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:48
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/34; B01J37/348; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8603; B01D53/8609; B01J35/00; B01J35/20; B01J35/27; C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; C01B17/0473; C01B17/0482; C01B17/48; C01B17/50; C01B17/58; C01B17/69; C01B17/74; C01B17/76; C01B17/78; C25; C25B; C25B1/00; C25B1/01
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
147 words
A PROCESS FOR REMOVING SULFUR DIOXIDE FROM A GASEOUS STREAM, COMPRISING THE STEPS OF: CONTACTING THE GASEOUS STREAM WITH A MOLTEN LIQUID HOMOGENEOUS CATALYST EXTRACTION SALT MIXTURE AT A TEMPERATURE BETWEEN 400*C. AND 500*C, HAVING (1) A DISSOLVED OXYGEN COMPOUND OF VANADIUM TO CATALYTICALLY OXIDIZE THE SULFUR DIOXIDE TO SULFUR TRIOXIDE AND (2) A DISSOLVED POTASSIUM NORMAL SULFATE TO SOLVATE THE SULFUR TRIOXIDE TO EXTRACT THE SULFUR TRIOXIDE FROM THE GASEOUS STREAM AND FORM A SULFUR DIOXIDE DEPLETED GASEOUS STREAM AND A SULFUR TRIOXIDE LOADED MOLTEN LIQUID SALT MIXTURE; SEPARATING THE SULFUR TRIOXIDE LOADED MOLTEN LIQUID SALT MIXTURE AND THE SULFUR DIOXIDE DEPLETED GASEOUS STREAM BEFORE THE MOLTEN SALT MIXTURE BECONES SATURATED WITH SULFUR TRIOXIDE; AND ELECTROLYTICALLY DISASSOCIATING THE SEPARATED SULFUR TRIOXIDE LOADED MOLTEN LIQUID SALT MIXTURE TO PRODUCE A GASEOUS EFFLUENT OF SULFUR TRIOXIDE AND TO REGENERATE AT LEAST A PORTION OF THE POTASSIUM NORMAL SULFATE.
Claim 2
Dependent Claim
147 words
A PROCESS FOR REMOVING SULFUR DIOXIDE FROM A GASEOUS STREAM, COMPRISING THE STEPS OF: CONTACTING THE GASEOUS STREAM WITH A MOLTEN LIQUID HOMOGENEOUS CATALYST EXTRACTION SALT MIXTURE AT A TEMPERATURE BETWEEN 400*C. AND 500*C, HAVING (1) A DISSOLVED OXYGEN COMPOUND OF VANADIUM TO CATALYTICALLY OXIDIZE THE SULFUR DIOXIDE TO SULFUR TRIOXIDE AND (2) A DISSOLVED POTASSIUM NORMAL SULFATE TO SOLVATE THE SULFUR TRIOXIDE TO EXTRACT THE SULFUR TRIOXIDE FROM THE GASEOUS STREAM AND FORM A SULFUR DIOXIDE DEPLETED GASEOUS STREAM AND A SULFUR TRIOXIDE LOADED MOLTEN LIQUID SALT MIXTURE; SEPARATING THE SULFUR TRIOXIDE LOADED MOLTEN LIQUID SALT MIXTURE AND THE SULFUR DIOXIDE DEPLETED GASEOUS STREAM BEFORE THE MOLTEN SALT MIXTURE BECONES SATURATED WITH SULFUR TRIOXIDE; AND ELECTROLYTICALLY DISASSOCIATING THE SEPARATED SULFUR TRIOXIDE LOADED MOLTEN LIQUID SALT MIXTURE TO PRODUCE A GASEOUS EFFLUENT OF SULFUR TRIOXIDE AND TO REGENERATE AT LEAST A PORTION OF THE POTASSIUM NORMAL SULFATE.
Claim 3
Dependent Claim
34 words
The sulfur dioxide removal process as defined in claim 1 further comprising the step of recycling the regenerated molten salt solution to the gaseous stream to form a continuous process of sulfur dioxide removal.
Claim 4
Dependent Claim
65 words
The sulfur dioxide removal process as defined in claim 1 wherein the separated sulfur trioxide loaded molten salt mixture is placed in an electrolytic cell having a cathode and an anode inserted into the molten mixture with an electrical potential applied across the cathode and anode to generate sulfur trioxide at the anode according to the formula: S2O7 -> 2SO3 + 1/2 O2 + 2e.
Claim 5
Dependent Claim
28 words
The sulfur dioxide removal process as defined in claim 1 wherein the molten salt mixture contacts the gaseous stream at a temperature between 425* C. and 460* C.
Claim 6
Dependent Claim
30 words
The sulfur dioxide removal process as defined in claim 1 wherein the molten liquid homogeneous catalyst extraction salt mixture consists essentially of vanadium pentoxide, potassium normal sulfate and potassium pyrosulfate.
Claim 7
Dependent Claim
50 words
The sulfur dioxide removal process as defined in claim 3 further comprising the step of placing a porous ceramic membrane in the electrolytic cell between the anode and cathode that is pervious to potassium metal ions to permit the potassium metal ions to migrate through the membrane to the cathode.
Claim 8
Dependent Claim
32 words
The sulfur dioxide removal process as defined in claim 1 further comprising the step of contacting the effluent gaseous sulfur trioxide with zinc oxide at approximately 427* C. to form zinc sulfate.
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) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |