Abstract: A reduction in the emission of infrared radiation by the engine of a jet aircraft can be achieved by employing a low molecular weight monohydric alcohol, having a luminometer number of at least about 200 as at least a portion of the fuel. Additional reduction in emission of infrared radiation can be achieved by passing a low molecular weight monohydric alcohol in indirect heat exchange relationship with the hot exhaust nozzle prior to its introduction to the combustion chamber of the engine.

Abstract: A method for burning a fuel, containing chemically bound nitrogen, in a two-stage, rich-lean combustion process, including; introducing the fuel and at least one stream of primary air into a primary combustion region at a fuel-air ratio above the stoichiometric ratio and in a manner to intimately mix the fuel and air and establish a stabilized flame adjacent the upstream end of the primary combustion region, maintaining the flame in the primary combustion region for a period of time sufficient to produce a combustion product mixture containing less than a predetermined amount of NO.sub.x pollutants and abruptly terminating the primary combustion region while introducing at least one stream of secondary air into the secondary region in an amount sufficient to reduce the overall fuel-air ratio below the stoichiometric ratio and in a manner to prevent backflow of the secondary air into the primary combustion region.

Abstract: A method for burning a fuel, containing chemically bound nitrogen, in a two-stage, rich-lean combustion process, including: introducing the fuel and at least one stream of primary air into a primary combustion region at a fuel-air ratio above the stoichiometric ratio and in a manner to intimately mix the fuel and air and establish a stabilized flame adjacent the upstream end of the primary combustion region, maintaining the flame in the primary combustion region for a period of time sufficient to produce a combustion product mixture containing less than a predetermined amount of NO.sub.x pollutants and abruptly terminating the primary combustion region while introducing at least one stream of secondary air into the secondary region in an amount sufficient to reduce the overall fuel-air ratio below the stoichiometric ratio and in a manner to prevent backflow of the secondary air into the primary combustion region.

Abstract: A method for burning a fuel, containing chemically bound nitrogen, in a two-stage, rich-lean combustion process, including; introducing the fuel and at least one stream of primary air into a primary combustion region at a fuel-air ratio above the stoichiometric ratio and in a manner to intimately mix the fuel and air and establish a stabilized flame adjacent the upstream end of the primary combustion region, maintaining the flame in the primary combustion region for a period of time sufficient to produce a combustion product mixture containing less than a predetermined amount of NO.sub.x pollutants and abruptly terminating the primary combustion region while introducing at least one stream of secondary air into the secondary region in an amount sufficient to reduce the overall fuel-air ratio below the stoichiometric ratio and in a manner to prevent backflow of the secondary air into the primary combustion region.

Abstract: A method of minimizing the production of SO.sub.x and NO.sub.x in the burning of a fuel containing significant amounts of SO.sub.x and NO.sub.x precursors in which the fuel is treated to remove significant amounts of SO.sub.x precursors without the removal of significant amounts of NO.sub.x precursors and the fuel is thereafter burned in a two-stage, rich-lean burning step in which significant amounts of the NO.sub.x precursors are converted to N.sub.2. Treating the fuel to remove SO.sub.x precursors is preferrably carried out in the presence of an oxidizing agent, such as H.sub.2 O.sub.2, a reducing agent, such as hydrogen, and/or steam, and still more preferably, the oxidizing agent, the reducing agent and steam are generated by burning an auxiliary fuel and passing the effluent thereof to the step of treating the fuel to remove SO.sub.x precursors.

Abstract: A method of extracting bitumen from a subsurface tar sand bed wherein a shell of frozen earth is formed around the periphery of at least a portion of the tar sand bed, followed by recovering bitumen from such portion of the tar sand bed within the shell of frozen earth by suitable means such as, for example, solvent extraction. Also disclosed is apparatus for freezing the earth surrounding one of a plurality of boreholes drilled in the earth within earth freezing distance of each other around the periphery of such portion of the tar sand bed.

Abstract: Bitumen is recovered from tar sand by extraction with a solvent. The bitumen solution is washed with water containing a cationic surfactant in order to remove sand fines therefrom.

Abstract: A fuel additive system comprising 10 to 50 parts by weight of a polybutene amine detergent having an average molecular weight in the range of 600-3,000 and having a nitrogen content in the range of 0.5 to 3 weight percent and 100 to 500 parts by weight of a solvent-refined paraffinic lubricating oil having a viscosity in the range of 250 to 500 SUS at 100.degree. F.