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US 4,087,130 AGranted
Process for the gasification of coal in situ
AssigneeOccidental Petroleum Corporation
InventorDonald E. Garrett
Life of this patent
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AssigneeOccidental Petroleum Corporation
InventorDonald E. Garrett
Estimating the term…
Process for the gasification of coal in situ comprising driving shafts or tunnels into a coal seam, injecting air into the bore holes to ignite and burn the coal to raise its temperature ceasing the flow of air when the coal is hot enough to support the endothermic water gas reaction, and injecting steam into the hot coal formation, such steam preferably being preheated by the flue gases taken from the same end of the bore holes where the air was injected, and recovering product gases, including carbon monoxide and hydrogen, and also product oil, exiting the tunnel at the other end of the bore holes. When the temperature of the coal drops during injection of steam to a level which will just permit combustion, the steam flow is stopped, and the cycle is repeated by air injection and flue gas removal at the front end of the bore holes, and through the tunnel connected therewith. This cyclic process is repeated until the entire mass of coal within the area encompassed by the bore holes is exhausted.
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal and injecting steam into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, removing said product gas at another end of said coal formation, thereby minimizing mixing of flue gas and product gas, said injection of said gaseous source of oxygen and said injection of steam being carried out in a cyclic manner, and continuing said combustion and gasification by said cyclic introducing of said gaseous source of oxygen and said steam into adjacent heated progressive portions of said coal formation.
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen through an inlet into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal, stopping the flow of said gaseous source of oxygen, injecting steam through an inlet into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, removing said product gas at another end of said coal formation remote from said one end of said coal formation, thereby minimizing mixing of flue gas and product gas, and substantially segregating flue gas from product gas, and when the temperature of said heated portion of said coal formation has dropped to a level which will just permit combustion, stopping the flow of said steam, and repeating the aforesaid cycle of reintroducing said gaseous source of oxygen and said steam alternately into adjacent heated progressive portions of said coal formation.
A process for the in situ gasification of coal which comprises forming substantially parallel access tunnels in a coal formation, forming a plurality of bore holes between adjacent parallel tunnels, the opposite ends of said bore holes communicating with said tunnels, providing a first manifold in one of said tunnels, one end of each of said bore holes connected to said first manifold, providing a second manifold in another adjacent one of said tunnels, the opposite ends of each of said bore holes connected to said second manifold, injecting alternately a gaseous source of oxygen and steam through said first manifold into one end of each of said bore holes to burn and gasify the coal in said formation adjacent each of said bore holes, removing flue gas from said one end of each of said bore holes but separated from said gaseous source of oxygen and said steam, and removing product gas exiting from the opposite end of each of said bore holes and through said second manifold, thereby substantially segregating flue gas from product gas.
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal simultaneously with injection of said gaseous source of oxygen, injecting steam into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, and removing product gas from said coal formation at another end thereof simultaneously with said steam injection, said injection of said gaseous source of oxygen and said injection of steam being carried out in a cyclic manner, and continuing said combustion and gasification by said cyclic introducing of said gaseous source of oxygen and said steam into adjacent heated progressive portions of said coal formation.
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal and injecting steam into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, removing said product gas at another end substantially opposite said one end of said coal formation, thereby minimizing mixing of flue gas and product gas, and substantially segregating flue gas from product gas, said injection of said gaseous source of oxygen and said injection of steam being carried out in a cyclic manner, and continuing said combustion and gasification by said cyclic introducing of said gaseous source of oxygen and said steam into adjacent heated progressive portions of said coal formation.
Dependencies are inferred from the claim text.