Patent US4155717A successfully refreshed from Google Patents.
US4155717A
Expired / Lapsed
US
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Process for removing sulfur from coal employing aqueous solutions of sulfites and bisulfites
Assignee: Atlantic Richfield Co
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Filing: 1978-01-03
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Granted: 1979-05-22
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Expires: 1998-01-03
Abstract
Abstract A process for reducing the sulfur content of coal comprising the steps of: (1) contacting coal particles with an aqueous solution of compositions selected from the group comprising alkali metal and alkaline earth metal sulfites and bisulfites to reduce the sulfur content of the coal; and (2) recovering coal particles of reduced sulfur content.
Inventors
- 👤 Jui-Yuan Sun
- 👤 Jin S. Yoo
- 👤 Emmett H. Burk, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:21
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
54 words
A process for reducing the sulfur content of coal comprising the steps of: (1) contacting coal particles with an aqueous solution of compositions selected from the group comprising alkali metal and/or alkaline earth metal sulfites and/or bisulfites to reduce the sulfur content of the coal; and (2) recovering coal particles of reduced sulfur content.
Claim 2
Dependent Claim
54 words
A process for reducing the sulfur content of coal comprising the steps of: (1) contacting coal particles with an aqueous solution of compositions selected from the group comprising alkali metal and/or alkaline earth metal sulfites and/or bisulfites to reduce the sulfur content of the coal; and (2) recovering coal particles of reduced sulfur content.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein the aqueous solution is maintained at a temperature of from about 100° C. to 500° C.
Claim 4
Dependent Claim
23 words
The process of claim 2 wherein the coal is contacted with the aqueous solution for a period of 30 minutes to 5 hours.
Claim 5
Dependent Claim
27 words
The process of claim 3 wherein the coal particles are contacted with an aqueous solution of compositions selected from the group comprising alkali metal sulfites and bisulfites.
Claim 6
Dependent Claim
29 words
The process of claim 3 wherein the coal particles are contacted with an aqueous solution of compositions selected from the group comprising potassium sulfite, sodium sulfite or mixtures thereof.
Claim 7
Dependent Claim
28 words
The process of claim 3 wherein the coal particles are contacted with an aqueous solution of compositions selected from the group comprising alkaline earth metal sulfites and bisulfites.
Claim 8
Dependent Claim
16 words
The process of claim 4 wherein the temperature is from about 200° C. to 500° C.
Claim 9
Dependent Claim
16 words
The process of claim 6 wherein the temperature is from about 200° C. to 500° C.
Claim 10
Dependent Claim
16 words
The process of claim 4 wherein the temperature is from about 175° C. to 350° C.
Claim 11
Dependent Claim
16 words
The process of claim 5 wherein the temperature is from about 175° C. to 350° C.
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) | 1982-05-21 | 1982-11-20 | 1983-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-21 | 1986-11-20 | 1987-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-21 | 1990-11-20 | 1991-05-22 | $7700.00 | Window Closed / Lapsed |