US4325707A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coal desulfurization by aqueous chlorination
Assignee: National Aeronautics and Space Administration
•
Filing: 1980-05-12
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Granted: 1982-04-20
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Expires: 2000-05-12
Abstract
Abstract A method of desulfurizing coal is described in which chlorine gas is bubbled through an aqueous slurry of coal at low temperature below 130 degrees C., and at ambient pressure. Chlorinolysis converts both inorganic and organic sulfur components of coal into water soluble compounds which enter the aqueous suspending media. The media is separated after chlorinolysis and the coal dechlorinated at a temperature of from 300 degrees C. to 500 degrees C. to form a non-caking, low-sulfur coal product.
Inventors
- 👤 John J. Kalvinskas
- 👤 Nick Vasilakos
- 👤 William H. Corcoran
- 👤 Karel Grohmann
- 👤 Naresh K. Rohatgi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:04
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
57 words
A method of desulfurizing coal comprising the steps of: suspending the coal in an aqueous medium consisting essentially of water to form a slurry; chlorinating the coal slurry at a temperature below 130 degrees C. by bubbling chlorine gas into the slurry to form water soluble sulfur compounds; and separating the chlorinated coal from the aqueous medium.
Claim 2
Independent Claim
57 words
A method of desulfurizing coal comprising the steps of: suspending the coal in an aqueous medium consisting essentially of water to form a slurry; chlorinating the coal slurry at a temperature below 130 degrees C. by bubbling chlorine gas into the slurry to form water soluble sulfur compounds; and separating the chlorinated coal from the aqueous medium.
Claim 3
Dependent Claim
23 words
A method according to claim 1 in which coal is present in the slurry in an amount from 15% to 60% by weight.
Claim 4
Dependent Claim
23 words
A method according to claim 2 in which coal is present in the slurry in an amount from 20% to 40% by weight.
Claim 5
Dependent Claim
27 words
A method according to claim 2 in which chlorine is added to the slurry in a stoichiometric ratio of 3.5-4.0 moles of chlorine per mole of sulfur.
Claim 6
Dependent Claim
19 words
A method according to claim 2 in which the coal has a particle size from 40 to 325 mesh.
Claim 7
Dependent Claim
31 words
A method according to claim 2 in which the temperature of the slurry is from 20 degrees C. to 100 degrees C. and the pressure is below 5 atmospheres during chlorination.
Claim 8
Dependent Claim
23 words
A method according to claim 6 further including the step of dechlorinating the separated coal to a chlorine content below 1% by weight.
Claim 9
Dependent Claim
28 words
A method according to claim 7 in which dechlorination is effected by heating the separated coal to a temperature of from 300 degrees C. to 500 degrees C.
Claim 10
Dependent Claim
21 words
A method according to claim 1 in which the coal contains an initial sulfur content of at least 0.2% by weight.
References Cited (Backward Citations)
US887145A
Cited
US2205410A
Cited
US3998604A
Cited
US4081250A
Cited
US4118200A
Cited
US4169710A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-04-19 | 1985-10-19 | 1986-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-19 | 1989-10-19 | 1990-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-19 | 1993-10-19 | 1994-04-20 | $7700.00 | Window Closed / Lapsed |