US4450066A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrothermal pretreatment to prevent scale during liquefaction of certain solid carbonaceous materials
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1982-11-08
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Granted: 1984-05-22
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Expires: 2002-11-08
Abstract
Abstract Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by hydrothermal pretreatment. The said pretreatment is believed to convert the scale-forming components to the corresponding carbonate prior to liquefaction. The said pretreatment is accomplished at a total pressure within the range from about 1000 to about 4400 psia. Temperature during said pretreatment will generally be within the range from about 500° to about 700° F.
Inventors
- 👤 John B. Stone
- 👤 Frank M. Floyd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:23
CPC Classifications
C; C10; C10G; C10G1/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
119 words
A process for the liquefaction of a lower ranking coal or similar solid carbonaceous material containing from about 20 to about 40 weight percent moisture consisting essentially of the steps of: (a) hydrothermally pretreating said coal or carbonaceous material by heating the coal or solid carbonaceous material to a temperature within the range from about 500° to about 700° F. at a total pressure at least 10% above the vapor pressure of water at the pretreating temperature to reduce the amount of alkaline earth metal humates therein; (b) liquefying the thus treated coal at liquefaction conditions to produce a petroleum-like product; and (c) recovering the liquid product from the unliquefied portion of the pretreated coal or similar carbonaceous material.
Claim 2
Dependent Claim
119 words
A process for the liquefaction of a lower ranking coal or similar solid carbonaceous material containing from about 20 to about 40 weight percent moisture consisting essentially of the steps of: (a) hydrothermally pretreating said coal or carbonaceous material by heating the coal or solid carbonaceous material to a temperature within the range from about 500° to about 700° F. at a total pressure at least 10% above the vapor pressure of water at the pretreating temperature to reduce the amount of alkaline earth metal humates therein; (b) liquefying the thus treated coal at liquefaction conditions to produce a petroleum-like product; and (c) recovering the liquid product from the unliquefied portion of the pretreated coal or similar carbonaceous material.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein the coal or similar solid carbonaceous material is ground such that all particles are less than 1/4 inch in diameter.
Claim 4
Dependent Claim
38 words
The process of claim 2 wherein the coal or similar carbonaceous material is combined with a solvent and heated for a period of time within the range from about 15 to about 120 minutes during the hydrothermal pretreatment.
Claim 5
Dependent Claim
25 words
The process of claim 1 wherein the nominal contacting time during the hydrothermal treatment is within the range from about 15 to about 120 minutes.
Claim 6
Dependent Claim
18 words
The method of claim 1 wherein the liquefaction is accomplished in the presence of a hydrogen donor solvent.
Claim 7
Dependent Claim
17 words
The method of claim 5 wherein the liquefaction is accomplished in the presence of added molecular hydrogen.
Claim 8
Dependent Claim
34 words
The method of claim 6 wherein the liquefaction is accomplished at a temperature of about 700° to about 950° F. and at a pressure within the range from about 300 to about 3000 psig.
References Cited (Backward Citations)
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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) | 1987-05-22 | 1987-11-21 | 1988-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-22 | 1991-11-21 | 1992-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-22 | 1995-11-21 | 1996-05-22 | $7700.00 | Window Closed / Lapsed |