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US4161440A
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Liquefaction of calcium-containing subbituminous coals and coals of lower rank
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1977-11-21
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Granted: 1979-07-17
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Expires: 1997-11-21
Abstract
Abstract An improved process for the treatment of a calcium-containing subbituminous coal and coals of lower rank to form insoluble, thermally stable calcium salts which remain within the solids portions of the residue on liquefaction of the coal, thereby suppressing the formation of scale, made up largely of calcium carbonate which normally forms within the coal liquefaction reactor (i.e., coal liquefaction zone), e.g., on reactor surfaces, lines, auxiliary equipment and the like. An oxide of sulfur, in liquid phase, is contacted with a coal feed sufficient to impregnate the pores of the coal. The impregnated coal, in particulate form, can thereafter be liquefied in a coal liquefaction reactor (reaction zone) at coal liquefaction conditions without significant formation of scale.
Inventors
- 👤 Roy J. Brunson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:47
CPC Classifications
C; C10; C10G; C10G1/00; C10G1/04; C10G1/042; Y; Y10; Y10S; Y10S208/00; Y10S208/951
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
76 words
A process for liquefying a calcium-containing subbituminous coal and coals of lower rank comprising: (a) contacting said coal with a sulfur oxide, maintained in the liquid phase, to form within the pores of said coal a water-insoluble, thermally stable calcium compound; and (b) liquefying the treated coal at a temperature within the range from about 700° F. to about 950° F. and at a pressure within the range from about 300 psia to about 3000 psia.
Claim 2
Dependent Claim
76 words
A process for liquefying a calcium-containing subbituminous coal and coals of lower rank comprising: (a) contacting said coal with a sulfur oxide, maintained in the liquid phase, to form within the pores of said coal a water-insoluble, thermally stable calcium compound; and (b) liquefying the treated coal at a temperature within the range from about 700° F. to about 950° F. and at a pressure within the range from about 300 psia to about 3000 psia.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein the sulfur oxide is sulfur dioxide.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein the sulfur oxide is sulfur trioxide.
Claim 5
Dependent Claim
20 words
The process of claim 1 wherein the sulfur oxide is constituted of an admixture of sulfur dioxide and sulfur trioxide.
Claim 6
Dependent Claim
18 words
The process of claim 1 wherein the sulfur oxide is dissolved in a solvent, and maintained under pressure.
Claim 7
Dependent Claim
26 words
The process of claim 5 wherein impregnation of the coal with the sulfur oxide is conducted at pressures ranging from about 0 to about 300 psig.
Claim 8
Dependent Claim
16 words
The process of claim 6 wherein the pressure ranges from about 10 to about 300 psig.
Claim 9
Dependent Claim
29 words
The process of claim 1 wherein contact between the particulate coal and the sulfur oxide is maintained for a period ranging at least about 0.01 to about 24 hours.
Claim 10
Dependent Claim
21 words
The process of claim 1 wherein the liquefaction is accomplished in the presence of a solvent which comprises a hydrogen-donor compound.
Claim 11
Dependent Claim
31 words
The process of claim 9 wherein the temperature of liquefaction ranges from about 800° F. to about 850° F., and the pressure ranges from about 800 psia to about 2000 psia.
Claim 12
Dependent Claim
37 words
The process of claim 9 wherein the hydrogen donor solvent is one which boils within a range of from about 400° F. to about 850° F., and contains at least about 30 wt. % hydrogen donor compounds.
Claim 13
Dependent Claim
37 words
The process of claim 9 wherein the coal is initially contacted with a first solvent which contains sulfur oxide, the coal is thereafter dried, and then contacted and liquified with a second solvent indigenous to the process.
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) | 1982-07-16 | 1983-01-15 | 1983-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-16 | 1987-01-15 | 1987-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-16 | 1991-01-15 | 1991-07-17 | $7700.00 | Window Closed / Lapsed |