Occidental Research Corporation

Occidental Oil Shale, Inc.

The United States of America As Represented by the Administrator of the

Leslie E Compton

Carole S Stover

William H Rowan

Eugene G Youngerman

Yields of soluble organic extract are increased up to about 50% by the supercritical extraction of particulate coal at a temperature below the polymerization temperature for coal extract fragments (450.degree. C.) and a pressure from 500 psig to 5,000 psig by the conjoint use of a solvent mixture containing a low volatility, high critical temperature coal dissolution catalyst such as phenanthrene and a high volatility, low critical temperature solvent such as toluene.

Supercritical solvent coal extraction

A method for determining kerogen content in oil shale is disclosed. The kerogen content of oil shale is measured by transmitting light of the infrared region of the electromagnetic spectrum through a sample containing comminuted oil shale and determining the amount of light absorbed by the kerogen in such sample. The amount of light of a selected wave number absorbed by the sample of comminuted oil shale is proportional to the Fischer Assay determination of kerogen content of such a sample. An internal standard having an absorbance within the infrared region of the electromagnetic spectrum at a wave number other than wherein oil shale has an absorbance is integrated into the sample of oil shale for providing an indication of the kerogen content within the oil shale sample upon comparison of the relative absorbance at the respective wave number of selected infrared light for the internal standard and the kerogen.

Infrared assay of kerogen in oil shale

A process for reducing the nitrogen content of shale oil by polymerizing the pyrrole compounds present in the shale oil by conditioning the shale oil with at least one of the following steps of acidifying the shale oil with a strong acid, heating the shale oil to at least about 85.degree. C., oxygenating the shale oil with an oxygen-supplying gas, and irradiating the shale oil with actinic radiation. The resulting pyrrole polymers are insoluble in the shale oil and are separated by liquid/solid separation techniques.

Process for removing nitrogen from shale oil using pyrrole polymerization

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.

Method for reducing the nitrogen content of shale oil

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.

A method is disclosed for reducing the nitrogen content of shale oil using mild hydrogenation followed by liquid sulfur dioxide extraction of the hydrogenated shale oil. The mild hydrogenation is effective for increasing the fraction of shale oil that is insoluble in the liquid sulfur dioxide. The mild hydrogenation is sufficient for saturating unsaturated compounds present in the shale oil to the substantial exclusion of adding hydrogen to the nitrogen of the nitrogen-containing compounds. Following hydrogenation of the shale oil, it is extracted with liquid sulfur dioxide at a temperature from about 14.degree. F. to about 60.degree. F. forming two fractions, a liquid sulfur dioxide insoluble fraction containing a relatively low nitrogen content and a liquid sulfur dioxide soluble fraction containing a relatively high nitrogen content. The liquid sulfur dioxide fraction is separated from the insoluble shale oil fraction. The liquid sulfur dioxide can be recovered for recycling to another extraction step.

Method for removing nitrogen from shale oil by hydrogenation and liquid

Crude shale oil produced by in situ retorting of oil shale can contain from about 1 to 2% sulfur by weight, the sulfur being distributed widely through the lower and higher boiling fractions of the shale oil. Substantially non-condensible sulfur containing gas such as hydrogen sulfide is evolved from such crude shale oil by maintaining such shale oil at an elevated temperature in the substantial absence of added reagent, with the maximum temperature below thermal decomposition temperatures of such shale oil for sufficient time to lower the sulfur content of the shale oil.

Removal of sulfur from shale oil

A crude shale oil is produced by in situ retorting of oil shale in a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort in a subterranean formation containing oil shale. A combustion zone is advanced through the fragmented mass by introducing an oxygen containing gas to the mass on the trailing side of the combustion zone and withdrawing an off gas from the fragmented mass on the advancing side of the combustion zone. Gas flow advances the combustion zone through the fragmented mass and transfers heat of combustion to a retorting zone on the advancing side of the combustion zone. Kerogen in oil shale in the retorting zone is decomposed to produce gaseous and liquid products including crude shale oil. Crude shale oil produced by such a process and having characteristics described herein is withdrawn from the fragmented mass on the advancing side of the retorting zone. A fraction, such as a low boiling fraction, a paraffin fraction, or a high boiling, paraffin rich fraction, is separated from a first portion of such crude shale oil to produce a modified shale oil having a pour point different from the pour point of the crude shale oil. The separated fraction is mixed with a second portion of shale oil to produce a blended shale oil having a pour point different from the pour point of the second portion of shale oil.

Controlling shale oil pour point

A technique is described for breaking the very strong emulsion of shale oil and water produced by an in situ oil shale retorting process so that separate shale oil and water phases can be recovered. The emulsion is broken by maintaining a volume of such emulsion at a bulk temperature of at least about 120.degree. F., and momentarily heating portions of emulsion to a temperature substantially higher than the bulk temperature of the emulsion. Preferably the emulsion of shale oil and water is held at a bulk temperature in the range of from about 120.degree. to 190.degree. F. in contact with heating means maintained in the range of from about 170.degree. F. to about 240.degree. F. Momentary localized heating of emulsion to a temperature substantially higher than the bulk temperature of the emulsion accelerates the breaking of the emulsion.

Method of breaking shale oil-water emulsion

The hydrocarbon, hydrogen and carbon monoxide concentration of a gas is reduced by reacting these constituents in the gas with oxygen in the presence of a fragmented permeable mass of combusted oil shale.

Oxidizing hydrocarbons, hydrogen, and carbon monoxide

The hydrogen sulfide concentration of a gas of relatively higher hydrogen sulfide concentration is reduced by introducing the gas to a fragmented permeable mass of oil shale for contacting the oil shale in the substantial absence of free oxygen. This yields a gas with relatively lower hydrogen sulfide concentration which is withdrawn from the fragmented permeable mass of oil shale.

Removing hydrogen sulfide from a gas

The hydrogen sulfide concentration of a gas is reduced by reacting hydrogen sulfide in the gas with oxygen in the presence of raw oil shale. The ratio of sulfur dioxide to sulfur produced by this reaction depends upon the molar ratio of oxygen to hydrogen sulfide present. Sulfur is the predominant product when hydrogen sulfide is reacted in the presence of oil shale with less than about 1 mole of oxygen for each 2 moles of hydrogen sulfide.

Method of oxidizing hydrogen sulfide

The hydrogen sulfide concentration of a gas of relatively higher hydrogen sulfide concentration is reduced by combining at a temperature less than about 650.degree. F hydrogen sulfide in the gas with oxygen in the presence of a fragmented permeable mass of particles containing oil shale to yield a gas with relatively lower hydrogen sulfide concentration for withdrawing from the fragmented permeable mass.

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Claremont, CA, United States of America

Leslie E Compton