Supercritical hydroextraction of kerogen from oil shale ores

Abstract

Water is added to reduce the hydrogen consumption in kerogen conversion. The water is not stripped from oil shale ores, instead up to 10% w / w of water is added in the kerogen conversion at 400-475° C. The recycle solvent for conversion is changed to a high boiling point fraction of the oil, with a minimum boiling point of the order of 245° C. Such repeated recycling of high boiling fraction oil with a hydrogen-donor mid-distillate will remove additional sulphur, oxygen and nitrogen. It improves the quality of the final product oil. Most of the high boiling fraction of the oil will separate from the oil shale ores, at around 450° C. and 650 psig. Then it is reduced to 250° C. at 100 psig before distillation. Such column operates at around 10 to 250 psig, but preferably 50 psig. This improves thermal efficiency by avoiding the need to condense high boiling point vapors. The addition of water provides further enhancement in operating results. A consequence of recycling high boiling oil fractions is the repeated hydrogenation and hydrocracking of that fraction to increase the proportions of lower boiling fractions. This reduces the asphaltene content of the recycled and final product streams. Such is similar to hydro-visbreaking of bitumen, in which both the asphaltene fraction and the sulphur content can be halved, resulting in a product of 25-30° API gravity in a single pass. The recycling of high boiling fraction means approximately half of the product oil is repeatedly recycled. There is no recycle of the low boiling fractions. It is expected that the intractable asphaltene content of about 5% of the product oil will be in suspension under hydro-treating and hydro-cracking conditions. These are removed with the solids after a supercritical solvent wash.

Description

RELATED PATENT APPLICATIONS [0001] This Patent application is a continuation-in-part of these previous U.S. patent application Ser. No. 09 / 490,254, filed Jan. 24, 2000, and titled APPARATUS AND METHOD FOR THE SUPERCRITICAL HYDRO EXTRACTION OF KEROGEN FROM OIL SHALE ORES; Ser. No. 10 / 247,868, filed Sep. 19, 2002, and titled SUPERCRITICAL HYDRO EXTRACTION OF KEROGEN AND AQUEOUS EXTRACTION OF ALUMINA AND SODA ASH WITH A RESIDUE FOR PORTLAND CEMENT PRODUCTION; and, Ser. No. 11 / 404,623, filed Apr. 13, 2006, and titled PROCESSING PLANT FOR PRODUCING STABLE PIPELINEABLE CRUDE OIL FROM KEROGENOUS OIL SHALES.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to processes for extracting the kerogen bituminous matter from oil shale ores to produce a pipelineable crude oil, and more particularly to extraction processes and apparatus that depend on super-critical hydrogen-donating (H-donating) solvents applied to carbonaceous oil shale ores with hig...

AI Technical Summary

Benefits of technology

[0022] Briefly, a process embodiment of the present invention is a method for producing pipelineable synthetic crude oil from oil shale ores including those including cannel coal. Water is added to reduce the hydrogen consumption in kerogen conversion. The water is not preliminarily stripped from oil shale ores as in other processes. Instead, up to 10% w / w of water is added in the kerogen conversion at 400-475° C. The recycle solvent for conversion is a high boiling point fraction of the oil, with a minimum boiling point of the order of 245° C.

[0023] Repeated recycling of high boiling fraction oil and a hydrogen-donor mid-distillate results in increases in the removal of sulphur, oxygen and nitrogen. Fewer contaminants means the quality of the final product oil is improved. Most of the Kerogen will be converted to oil by the high boiling fraction of the oil, and will be separated from the shale residue, at around 450° C. and 650 psig. Then the separated oil is reduced to 250° C. at 100 psig before distillation. Such column operates at around 10 to 250 psig, but preferably 50 psig. This improves thermal efficiency by avoiding the need to condense high boiling point vapors. The addition of water provides further enhancement in operating results.

[0024] A consequence of recycling high boiling oil fractions is the repeated hydrogenation and hydrocracking of that fraction to increase the proportions of lower boiling fractions. This reduces the asphaltene content of the recycled and final product streams. Such is similar to hydro-visbreaking of bitumen, in which both the asphaltene fraction and the sulphur content can be halved, resulting in a product of 25-30° API gravity in a single pass.

Problems solved by technology

This reduces the asphaltene content of the recycled and final product streams.

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