1
Ottfried J Hahn: Method and apparatus for conversion of coal in situ. University of Kentucky Research Foundation, King and Schickli, October 11, 1988: US04776638 (299 worldwide citation)

A method for the electro-thermal and electrochemical underground conversion of coal into oil and by-products comprises the steps of inserting an underground probe into a bore hole until the probe is in close proximity to a coal seam. A mixture of air, steam, an electrolyte and a suitable catalyst is ...


2
Ruel C Terry: Minimizing environmental effects in production and use of coal. In Situ Technology, September 19, 1978: US04114688 (251 worldwide citation)

Coal gas is produced in situ using the techniques of gasification, liquefaction and pyrolysis. Normal effluents to the atmosphere are recycled in part to the underground reaction zone for conversion into commercial products. Contaminants to underground aquifers are captured and injected into the und ...


3
Lawrence B Owen, John F Schatz, Usman Ahmed: Method of in-situ retorting of carbonaceous material for recovery of organic liquids and gases. Terra Tek, M Reid Russell, May 24, 1983: US04384613 (248 worldwide citation)

The method of the present invention involves a two-phase process for in-situ retorting and recovery of carbonaceous material contained within typical subterranean tar sand formations, and includes formation of conventional arrays of in-seam ducts, and positioning heating devices to heat a section of ...


4
Armand A Gregoli: Method of in-situ hydrogenation of carbonaceous material. Cities Service Company, George L Rushton, William N Patrick, February 26, 1985: US04501445 (241 worldwide citation)

In-situ hydrogenation of an underground coal formation is carried out by fracturing the formation and sealing it, to provide an in-situ reactor site. Then a liquid solvent stream and a gaseous hydrogen stream are introduced into the fractured formation, allowing reaction and conversion of the coal t ...


5
Harold J Vinegar, Kevin Albert Maher, Scott Lee Wellington: Upgrading and mining of coal. Shell Oil Company, November 29, 2005: US06969123 (240 worldwide citation)

A method for treating a coal formation to alter properties of coal in the formation is provided. In one embodiment, heat from one or more heaters may be provided to at least a portion of the formation. Heat may be allowed to transfer from the one or more heaters to a part of the formation. In certai ...


6
Clarence I Justheim: Method of retorting oil shale by velocity flow of super-heated air. Justheim Pertroleum Company, Mallinckrodt & Mallinckrodt, May 24, 1983: US04384614 (239 worldwide citation)

Oil shale is retorted, preferably in situ, by passing velocity flow of super-heated air through one or more conduit-like passages in direct contact with exposed surfaces of oil shale. Kerogen pyrolysis products are recovered by condensation of the vapors and collection of the condensate and by colle ...


7
Arnold W J Grupping: Coal gasification method. William A Drucker, January 6, 1981: US04243101 (234 worldwide citation)

A method for underground gasification of coal or brown coal, in which a substantially uniform gasification or combustion front is maintained by filling the cavity generated by gasification of coal with a filler so as to drive said front in an upward direction through the coal layer, the gases for ma ...


8
Stirling A Colgate: In situ solution mining of coal. New Mexico Tech Research Foundation, Brumbaugh Graves Donohue & Raymond, August 10, 1976: US03973628 (233 worldwide citation)

Underground strata surrounding a coal seam are prestressed by repeated fracturing with a settable material to strengthen and seal the strata to contain a hydrostatic pressure in the coal seam of about 100 to about 500 atmospheres, thereby providing a gas and liquid-tight seal surrounding and within ...


9
Lucio V Reale, William R McKay: Treatment of underground beds. Townsend and Townsend, April 17, 1984: US04442896 (232 worldwide citation)

A method of preparing an underground bed for treatment. A channel is formed in the bed extending from the ground down through the bed and up to the ground. A cutting device is inserted into the channel operated to form a pathway in a substantially vertical plane.


10
Ruel Carlton Terry: Generating medium BTU gas from coal in situ. In Situ Technology, July 11, 1978: US04099567 (230 worldwide citation)

Medium BTU gas is generated from coal in situ by establishing communication channels through the coal in part by projectiles and in part by burning. Oxygen is employed for reaction with the coal and reaction temperatures are controlled by injection of steam.



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