Coal comminution and recovery process using gas drying
AssigneeMobil Oil Corporation
InventorJu-Nam Chew
Life of this patent
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Abstract
This invention is a comminution process for treating coal with a drying gas to form fractures which weaken the structure of the coal and make it easier to disintegrate mechanically, chemically or by fluid force. Another aspect of this invention is a process for treating an underground formation of coal with a dry gas for a time sufficient to form cracks and fractures in a portion of the formation in order to increase the permeability of the coal formation to the flow of fluids therethrough. Processes for in-situ combustion of the coal formation are therefore more efficient since the coal formation is more permeable to the flow of gas therethrough.
Claims11
An improved process for comminuting coal wherein the coal is treated with an effective amount of a solvent selected from the group consisting of a basic aqueous solution and methanol, the improvement comprising first contacting said coal with a drying gas and continuing to contact said coal with said drying gas for a time sufficient to fracture at least a portion of said coal by the absorption of moisture from the coal thereby enhancing comminution.
An improved process for comminuting coal wherein the coal is treated with an effective amount of gaseous anhydrous ammonia, the improvement comprising first contacting said coal with a drying gas and continuing to contact said coal with said drying gas for a time sufficient to fracture at least a portion of said coal by the absorption of moisture from the coal thereby enhancing comminution.
In a process for recovering subterranean coal which comprises contacting a coal seam in-situ with a basic aqueous solution and maintaining said contact for a time sufficient to fragment at least a portion of said coal, disintegrating said portion to form a slurry, and transporting said slurry to the earth's surface to a storage vessel, the improvement comprising first injecting into the coal seam a drying gas;
- continuing to inject said dry gas into said coal seam for a time sufficient to fracture at least a portion of said coal by the absorption of moisture from the coal;
- and withdrawing moistened gas from the coal seam.
Dependencies are inferred from the claim text.