Abstract: Hydrocarbon liquids and/or gases are recovered from thick underground deposits of oil-bearing limestone or dolomite by drilling two or more boreholes from the earth's surface into the lower part of the deposit, establishing communication between the boreholes, burning the oil in said limestone or dolomite in an area between the boreholes to decompose the alkaline earth carbonate into alkaline earth oxide, flushing out the alkaline earth oxide formed by the combustion with water to form a cavity, collapsing the overlying oil-bearing limestone or dolomite into the cavity to form a rubblized zone extending vertically to a point near the upper boundary of the deposit, driving a flame front vertically through the rubblized zone to liberate hydrocarbon liquids and produce gases, and recovering the liquids and/or gases from the rubblized zone.

Abstract: Methane and carbon dioxide are produced by reacting steam with a carbonaceous feed material at a reaction temperature between about 1000.degree. F. and about 1500.degree. F. and a reaction pressure in excess of about 100 psia in the presence of a carbon-alkali metal catalyst and equilibrium quantities of added hydrogen and carbon monoxide. The raw product gas withdrawn from the reaction zone is treated for removal of the carbon dioxide, product methane is recovered from the treated gas, and the remaining hydrogen and carbon monoxide can be recycled to supply the added hydrogen and carbon monoxide needed in the reaction zone.

Abstract: Coal liquids and gases are recovered from a thick underground coal seam by drilling one or more boreholes from the earth's surface into the lower part of the seam, burning out the coal over a limited area near the bottom of the seam, collapsing the overlying coal to form a rubblized zone extending vertically to a point near the upper boundary of the seam, driving a flame front vertically through the rubblized zone to liberate hydrocarbon liquids and produce gases, and recovering the liquids and gases from the rubblized zone.

Abstract: Methane is produced by contacting a mixture of carbon monoxide or carbon dioxide and hydrogen with a carbon-alkali metal catalyst at a temperature in the range between about 800.degree.F. and about 1500.degree.F. and at a pressure between about atmospheric and about 2000 psig. The catalyst employed may be prepared by heating an intimate mixture of coal, coal char, coke or other carbonaceous solids and an alkali metal salt, hydroxide or similar constituent. Such a catalyst promotes the methanation of carbon monoxide and carbon dioxide and the formation of higher hydrocarbons by the Fischer-Tropsch reaction and at the same time is resistant to high temperature sintering and poisoning by sulfur compounds present in the feed gas. The catalyst can be regenerated if necessary by air oxidation.