US4071328A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of removing sulfur from coal
Assignee: Dow Chemical Co
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Filing: 1976-01-22
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Granted: 1978-01-31
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Expires: 1996-01-22
Abstract
Abstract A process of reducing the total sulfur content of coal is disclosed. The process comprises hydrogenating the coal to remove at least a portion of the recoverable sulfur combined as pyritic sulfur. The hydrogenated coal is subsequently contacted with a sufficient amount of an aqueous inorganic acid solution to remove at least a portion of the remaining sulfur initially combined as pyritic sulfur.
Inventors
- 👤 Gerard C. Sinke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:02
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/02
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
60 words
A process of reducing the total sulfur content of coal comprising: hydrogenating the coal to convert at least a portion of the recoverable sulfur combined as pyritic sulfur to iron (II) sulfide; contacting the hydrogenated coal with a sufficient amount of an aqueous hydrochloric acid solution to remove at least a portion of the sulfur combined as iron (II) sulfide.
Claim 2
Dependent Claim
60 words
A process of reducing the total sulfur content of coal comprising: hydrogenating the coal to convert at least a portion of the recoverable sulfur combined as pyritic sulfur to iron (II) sulfide; contacting the hydrogenated coal with a sufficient amount of an aqueous hydrochloric acid solution to remove at least a portion of the sulfur combined as iron (II) sulfide.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein the coal is hydrogenated under a pressure of from about 200 to about 550 pounds per square inch gauge.
Claim 4
Dependent Claim
20 words
The process of claim 1 wherein the coal has a particle size of less than about 100 U.S. Standard Mesh.
Claim 5
Dependent Claim
21 words
The process of claim 1 wherein the coal is hydrogenated at a temperature of from about 300° to about 350° C.
Claim 6
Dependent Claim
16 words
The process of claim 4 wherein the coal is hydrogenated for at least about 2 hours.
Claim 7
Dependent Claim
19 words
The process of claim 4 wherein the coal is hydrogenated for from about 2 hours to about 4 hours.
Claim 8
Dependent Claim
22 words
The process of claim 1 wherein the coal is hydrogenated at a temperature of from about 320° C to about 350° C.
Claim 9
Dependent Claim
32 words
The process of claim 1 wherein the coal is hydrogenated for a sufficient time to convert at least a portion of the recoverable sulfur combined as pyritic sulfur to iron (II) sulfide.
Claim 10
Dependent Claim
44 words
The process of claim 1 wherein the contacting is carried out by digesting the hydrogenated coal with a sufficient amount of the aqueous hydrochloric acid solution to react with and thereby remove at least a portion of the sulfur present as iron (II) sulfide.
Claim 11
Dependent Claim
16 words
The process of claim 1 wherein the aqueous hydrochloric acid solution is one normal hydrochloric acid.
Claim 12
Dependent Claim
28 words
The process of claim 1 wherein the hydrogenated coal is contacted with the aqueous hydrochloric acid solution at a temperature of about 40° C to about 80° C.
Claim 13
Dependent Claim
20 words
The method of claim 1 wherein the coal is selected from the group consisting of bituminous, anthracite, sub-bituminous, and lignite.
Claim 14
Dependent Claim
109 words
A process of reducing the total sulfur content of coal comprising: a. hydrogenating the coal under a pressure of from about 200 to about 550 pounds per square inch gauge at a temperature of from about 300° C to about 350° C for a sufficient time to convert at least a portion of the recoverable sulfur combined as pyritic sulfur to iron (II) sulfide; b. contacting the hydrogenated coal at a temperature of from about 40° C to about 80° C with a sufficient amount of an aqueous hydrochloric acid solution to react with and thereby remove at least a portion of the sulfur combined as iron (II) sulfide.
Claim 15
Dependent Claim
109 words
A process of reducing the total sulfur content of coal comprising: a. hydrogenating the coal under a pressure of from about 200 to about 550 pounds per square inch gauge at a temperature of from about 300° C to about 350° C for a sufficient time to convert at least a portion of the recoverable sulfur combined as pyritic sulfur to iron (II) sulfide; b. contacting the hydrogenated coal at a temperature of from about 40° C to about 80° C with a sufficient amount of an aqueous hydrochloric acid solution to react with and thereby remove at least a portion of the sulfur combined as iron (II) sulfide.
Claim 16
Dependent Claim
18 words
The process of claim 13 wherein the aqueous hydrochloric acid solution is a one normal hydrochloric acid solution.
Claim 17
Dependent Claim
25 words
The process of claim 13 wherein the hydrogenation and contacting remove at least about 75 percent of the recoverable sulfur initially combined as pyritic sulfur.
Claim 18
Dependent Claim
19 words
The process of claim 13 wherein the hydrogenated coal is contacted with substantially only an aqueous hydrochloric acid solution.
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) | 1981-01-30 | 1981-08-01 | 1982-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-30 | 1985-08-01 | 1986-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-30 | 1989-08-01 | 1990-01-31 | $7700.00 | Window Closed / Lapsed |