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US4213752A Expired / Lapsed US ⏱️ 0.0 years remaining

Coal drying process

Assignee: Sunoco Inc R&M
•
Filing: 1978-11-06
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Granted: 1980-07-22
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Expires: 1998-11-06
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Abstract

Abstract A single step process for removing moisture from low rank coal using in-situ generated thermal energy by passing the wet low rank coal at room temperature into a moving bed of hot coal at a temperature in the range of from about 200° C. to about 300° C. at a rate to maintain partial combustion of the coal at atmospheric pressure, and in the presence of a gas at atmospheric pressure containing from about 5% to about 20% by volume of oxygen, the heat generated by the combustion being absorbed by the wet coal being fed to the system and being effective for drying the coal to the desired level, and separating the dried coal from the combustion zone, whereby the dry coal obtained is highly resistant to spontaneous combustion.

Inventors

  • 👤 Walter H. Seitzer

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 06:32
CPC Classifications
C; C10; C10F; C10F5/00; C10L; C10L9/00; C10L9/08

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 138 words
A single step process for removing moisture from low rank coal using in-situ generated thermal energy by (a) feeding the wet low rank coal at room temperature into a moving bed of hot coal at a temperature in the range of from about 200° C. to about 300° C. at a rate to maintain partial combustion of the coal at atmospheric pressure, (b) maintaining said coal bed in the presence of a gas at atmospheric pressure containing from about 5% to about 20% by volume of oxygen, whereby the in-situ heat generated by the combustion is absorbed by the wet coal being fed to the system and is effective for drying the coal to the desired level, and (c) separating the dried coal from the combustion zone, whereby the dry coal obtained is highly resistant to spontaneous combustion.
Claim 2
Dependent Claim 138 words
A single step process for removing moisture from low rank coal using in-situ generated thermal energy by (a) feeding the wet low rank coal at room temperature into a moving bed of hot coal at a temperature in the range of from about 200° C. to about 300° C. at a rate to maintain partial combustion of the coal at atmospheric pressure, (b) maintaining said coal bed in the presence of a gas at atmospheric pressure containing from about 5% to about 20% by volume of oxygen, whereby the in-situ heat generated by the combustion is absorbed by the wet coal being fed to the system and is effective for drying the coal to the desired level, and (c) separating the dried coal from the combustion zone, whereby the dry coal obtained is highly resistant to spontaneous combustion.
Claim 3
Dependent Claim 16 words
The process of claim l where the coal combustion is carried out in a moving bed.
Claim 4
Dependent Claim 13 words
The process of claim 2 wherein the moving bed is a fluidized bed.
Claim 5
Dependent Claim 154 words
A single step process for removing moisture from low rank coal using in-situ generated thermal energy by (a) passing the wet low rank coal at room temperature into a moving bed of hot coal at a rate to maintain partial combustion of the coal so that from about 5% to about 10% by weight of said coal is oxidized, (b) maintaining said process at atmospheric pressure and at a temperature in the range of from about 200° C. to about 300° C. by feeding to said coal bed a gas at atmospheric pressure containing from about 5% to about 20% by volume of oxygen, whereby the heat generated by the combustion is absorbed by the wet coal being fed to the system and is effective for drying the coal to the desired level, and (c) separating the dried coal from the combustion zone, whereby the dry coal obtained is highly resistant to spontaneous combustion.
Claim 6
Dependent Claim 154 words
A single step process for removing moisture from low rank coal using in-situ generated thermal energy by (a) passing the wet low rank coal at room temperature into a moving bed of hot coal at a rate to maintain partial combustion of the coal so that from about 5% to about 10% by weight of said coal is oxidized, (b) maintaining said process at atmospheric pressure and at a temperature in the range of from about 200° C. to about 300° C. by feeding to said coal bed a gas at atmospheric pressure containing from about 5% to about 20% by volume of oxygen, whereby the heat generated by the combustion is absorbed by the wet coal being fed to the system and is effective for drying the coal to the desired level, and (c) separating the dried coal from the combustion zone, whereby the dry coal obtained is highly resistant to spontaneous combustion.
Claim 7
Dependent Claim 16 words
The process of claim 4 wherein the coal combustion is carried out in a fluidized bed.
Claim 8
Dependent Claim 12 words
The process of claim 5 wherein the coal is a Montana Lignite.
Claim 9
Dependent Claim 13 words
The process of claim 5 wherein the coal is a Wyoming subbituminous coal.
Claim 10
Dependent Claim 11 words
The process of claim 5 wherein the coal is Wyodak coal.
Claim 11
Dependent Claim 11 words
The process of claim 5 wherein the coal is Savage coal.

References Cited (Backward Citations)

US2668099A Cited
US2666269A Cited
US2763478A Cited
US2704895A Cited
US2871004A Cited
US2844886A Cited
US3723079A Cited
US3896557A Cited
US4043763A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-07-22 1984-01-21 1984-07-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-07-22 1988-01-21 1988-07-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-07-22 1992-01-21 1992-07-22 $7700.00 Window Closed / Lapsed

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