Abstract: An improvement in the production of low mineral content fuel by coal liquefaction processes which yield as a primary product a mixture of liquid and solids a part of which are suspended in the liquid whereby the separation of the suspended solids is facilitated by the addition of an effective amount of a suitable chelating agent to the mixture. The chelating agent is optionally added as a solution of the chelating agent in a suitable solvent and desirably is present in an amount from about 100 to about 150% of the stoichiometric amount required to react with the suspended solids in the mixture.

Abstract: Oxygen compounds are removed, e.g., by solvent extraction, from a shale oil prior to its hydrogenation. As a result, the amount of hydrogen consumed during subsequent hydrogenation to achieve a given level of nitrogen for the shale oil is less than that which would occur if the oxygen compounds were not removed from the shale oil. Removal of the nitrogen is necessary to avoid adverse effects on subsequent shale oil processing steps such as catalytic cracking.

Abstract: A method is disclosed for reducing the nitrogen content of shale oil by removing nitrogen-containing compounds from the shale oil. The shale oil containing nitrogen-containing compounds is extracted with a sufficient amount of selective solvent which is selective toward the nitrogen-containing compounds present in the shale oil. The selective solvent comprises an active solvent for nitrogen-containing compounds and water in an amount sufficient to provide phase separation. The active solvent component of the selective solvent is selected from the group consisting of organic acids, and substituted organic acids, particularly acetic, formic and trichloroacetic acids and mixtures thereof. The selective solvent containing the nitrogen-containing compounds is separated from the reduced nitrogen content shale oil raffinate by phase disengagement.

Abstract: Methods are disclosed for reducing the nitrogen content of shale oil by selectively removing therefrom nitrogen-containing compounds. The nitrogen content of shale oil is reduced by a process comprising lowering the viscosity of the shale oil and then contacting the shale oil with a sufficient amount of a solvent which is selective toward the nitrogen-containing compounds present in the shale oil. The selective solvent is selected from the group consisting of organic acids, and substituted organic acids, particularly acetic, formic and trichloroacetic acids and mixtures thereof. The selective solvent system containing the nitrogen-containing compounds is separated from the reduced nitrogen content shale oil raffinate.

Abstract: A process for increasing the octane rating of gasoline and decreasing the quantity of coke produced by a catalytic cracking process by adding C.sub.2 to C.sub.6 linear olefins to the feed to the reactor with a zeolite containing cracking catalyst. The olefins may be added separately or mixed with the gas oil feed just before the oil preheat section ahead of the reactor.

Abstract: Oil is separated from impurities in crude oil residue by (1) mixing and agitating the oil residue with a solvent, such as naphtha, light oil or kerosene, (2) subjecting the mixture to a centrifugal separator to separate a solvent-oil mixture from the residue impurities. The structure of the centrifugal separator includes a rotating separator unit having a fine mesh wall and located within a heated, spaced cylindrical body.