US4081250A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coal desulfurization process
Assignee: California Institute of Technology
•
Filing: 1976-08-27
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Granted: 1978-03-28
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Expires: 1996-08-27
Abstract
Abstract A method of chlorinolysis of coal in an organic solvent at a moderate temperature and atmospheric pressure has been proven to be effective in removing sulfur, particularly the organic sulfur, from coal. Chlorine gas is bubbled through a slurry of moist coal in chlorinated solvent. The chlorinated coal is separated, hydrolyzed and then dechlorinated. Preliminary results of treating a high sulfutr (4.77%S) bituminous coal show that up to 70% organic sulfur, 90% pyritic sulfur and 76% total sulfur can be removed. The treated coal is dechlorinated by heating at 500 DEG C. The presence of moisture helps to remove organic sulfur.
Inventors
- 👤 George C. Hsu
- 👤 George R. Gavalas
- 👤 Partha S. Ganguli
- 👤 Sarkis H. Kalfayan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:11
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/02
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
92 words
A method of desulfurizing particulate coal comprising the steps of: suspending the coal in an organic solvent having a boiling point below 120° C and having good resistance to consumption of chlorine to form a slurry; chlorinating the coal by adding chlorine gas to the coal slurry at a temperature below 120° C for a time sufficient to add 10 to 50% by weight chlorine to the coal; separating chlorinated coal from the solvent; suspending the chlorinated coal in water and leaching water soluble sulfur compounds therefrom; and recovering chlorinated desulfurized coal.
Claim 2
Independent Claim
92 words
A method of desulfurizing particulate coal comprising the steps of: suspending the coal in an organic solvent having a boiling point below 120° C and having good resistance to consumption of chlorine to form a slurry; chlorinating the coal by adding chlorine gas to the coal slurry at a temperature below 120° C for a time sufficient to add 10 to 50% by weight chlorine to the coal; separating chlorinated coal from the solvent; suspending the chlorinated coal in water and leaching water soluble sulfur compounds therefrom; and recovering chlorinated desulfurized coal.
Claim 3
Dependent Claim
16 words
A method according to claim 1 in which the organic solvent is a chlorinated liquid hydrocarbon.
Claim 4
Dependent Claim
15 words
A method according to claim 2 in which the solvent is a chlorinated aliphatic hydrocarbon.
Claim 5
Dependent Claim
13 words
A method according to claim 3 in which the solvent is methyl chloroform.
Claim 6
Dependent Claim
18 words
A method according to claim 1 in which the coal contains up to 100% by weight of moisture.
Claim 7
Dependent Claim
16 words
A method according to claim 5 in which the coal contains from 10 to 100% moisture.
Claim 8
Dependent Claim
21 words
A method according to claim 5 in which the ratio of solvent to coal is from 5 to 50% by weight.
Claim 9
Dependent Claim
16 words
A method according to claim 1 in which chlorine gas is bubbled through the coal slurry.
Claim 10
Dependent Claim
19 words
A method according to claim 8 in which the coal has a particle size from 60 to 325 mesh.
Claim 11
Dependent Claim
24 words
A method according to claim 9 in which the temperature is from 20° to 80° C and the pressure is one atmosphere during chlorinolysis.
Claim 12
Dependent Claim
28 words
A method according to claim 1 further including the step of reducing the chlorine content of the chlorinated, desulfurized coal to a chlorine content below 3% by weight.
Claim 13
Dependent Claim
27 words
A method according to claim 11 in which chlorine content reduction is effected by heating the chlorinated, desulfurized coal at a temperature from 300° to 600° C.
Claim 14
Dependent Claim
25 words
A method according to claim 11 further including the step of recovering excess chlorine and recycling it to the chlorine inlet to the chlorination step.
Claim 15
Dependent Claim
25 words
A method according to claim 13 in which excess chlorine and HCl are recovered from the chlorination step, coal recovery step and chlorine reducing step.
Claim 16
Dependent Claim
24 words
A method according to claim 1 further including the step of recycling solvent from the separation step to the inlet to the suspension step.
Claim 17
Dependent Claim
15 words
A method according to claim 15 in which separation is effected by filtration and distillation.
Claim 18
Dependent Claim
32 words
A method according to claim 1 in which leaching is effected in water at a temperature of 20° to 80° C until the residual total sulfur content is below 1.5% by weight.
Claim 19
Dependent Claim
104 words
A coal desulfurization system comprising in combination: means for forming a suspension of coal in organic solvent to form a slurry; chlorination means connected to the suspension means for receiving said slurry and having an inlet for bubbling chlorine gas through said slurry to form chlorinated coal; separation means connected to the chlorination means for separating solvent from the chlorinated coal; aqueous leaching means connected to the separation means for receiving the chlorinated coal for removing soluble sulfur compounds therefrom; and dechlorination means connected to the leaching means for receiving the leached coal and including heating means for removing chlorine from the chlorinated coal.
Claim 20
Dependent Claim
104 words
A coal desulfurization system comprising in combination: means for forming a suspension of coal in organic solvent to form a slurry; chlorination means connected to the suspension means for receiving said slurry and having an inlet for bubbling chlorine gas through said slurry to form chlorinated coal; separation means connected to the chlorination means for separating solvent from the chlorinated coal; aqueous leaching means connected to the separation means for receiving the chlorinated coal for removing soluble sulfur compounds therefrom; and dechlorination means connected to the leaching means for receiving the leached coal and including heating means for removing chlorine from the chlorinated coal.
Claim 21
Dependent Claim
20 words
A system according to claim 10 further including means for recycling excess chlorine from the chlorination means to said inlet.
Claim 22
Dependent Claim
21 words
A system according to claim 19 further including means for recycling solvent recovered from said separation means to said suspension means.
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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) | 1981-03-27 | 1981-09-26 | 1982-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-27 | 1985-09-26 | 1986-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-27 | 1989-09-26 | 1990-03-28 | $7700.00 | Window Closed / Lapsed |