Hydrocracking of heavy hydrocarbon oils with conversion facilitated by control of polar aromatics
First Claim
1. A process for hydrocracking a heavy hydrocarbon oil feedstock, a substantial portion of which boils above 524°
- C. which comprises;
(a) passing a slurry feed of a mixture of heavy hydrocarbon oil feedstock and from about 0.01-4.0% by weight (based on fresh feedstock) of coke-inhibiting additive particles comprising particles of an iron compound having sizes less than 45 μ
m upwardly through a confined vertical hydrocracking zone in the presence of hydrogen and in the absence of an active hydrogenation catalyst, said hydrocracking zone being maintained at a temperature between about 350° and
600°
C. a pressure of at least 3.5 MPa and a space velocity of up to 4 volumes of hydrocarbon oil per hour per volume of hydrocracking zone capacity,(b) removing from the top of said hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid phase comprising heavy hydrocarbons,(c) passing said mixed effluent into a hot separator vessel,(d) withdrawing from the top of the separator a gaseous stream comprising hydrogen and vaporous hydrocarbons,(e) withdrawing from the bottom of the separator a liquid stream comprising liquid hydrocarbons and particles of the coke-inhibiting additive,(f) fractionating the separated liquid stream to obtain a pitch bottom stream which boils above 495°
C., said pitch stream containing said additive particles, and an aromatic heavy gas oil fraction,(g) recycling at least part of said pitch stream containing additive particles to form part of the feedstock to the hydrocracking zone, and(h) recycling at least part of said aromatic heavy gas oil fraction to form part of the feedstock to the hydrocracking zone.
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Accused Products
Abstract
A process for hydrocracking a heavy hydrocarbon oil feedstock, a substantial portion of which boils above 524° C. is described which includes the steps of: (a) passing a slurry feed of a mixture of heavy hydrocarbon oil feedstock and from about 0.01-4.0% by weight (based on fresh feedstock) of coke-inhibiting additive particles upwardly through a confined vertical hydrocracking zone, the hydrocracking zone being maintained at a temperature between about 350° and 600° C. a pressure of at least 3.5 MPa and a space velocity of up to 4 volumes of hydrocarbon oil per hour per volume of hydrocracking zone capacity, (b) removing from the top of the hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid phase comprising heavy hydrocarbons, (c) passing the mixed effluent into a hot separator vessel, (d) withdrawing from the top of the separator a gaseous stream comprising hydrogen and vaporous hydrocarbons, (e) withdrawing from the bottom of the separator a liquid stream comprising heavy hydrocarbons and particles of the coke-inhibiting additive, and (f) fractionating the separated liquid stream to obtain a heavy hydrocarbon stream which boils above 450° C. said heavy hydrocarbon stream containing said additive particles, and a light oil product. According to the novel feature, at least part of the fractionated heavy hydrocarbon stream boiling above 450° C. is recycled to form part of the heavy hydrocarbon oil feedstock at a lower polarity aromatic oil is added to the heavy hydrocarbon oil feedstock such that a high ratio of lower polarity aromatics to asphaltenes is maintained during hydroprocessing. This provides excellent yields without coke formation.
96 Citations
10 Claims
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1. A process for hydrocracking a heavy hydrocarbon oil feedstock, a substantial portion of which boils above 524°
- C. which comprises;
(a) passing a slurry feed of a mixture of heavy hydrocarbon oil feedstock and from about 0.01-4.0% by weight (based on fresh feedstock) of coke-inhibiting additive particles comprising particles of an iron compound having sizes less than 45 μ
m upwardly through a confined vertical hydrocracking zone in the presence of hydrogen and in the absence of an active hydrogenation catalyst, said hydrocracking zone being maintained at a temperature between about 350° and
600°
C. a pressure of at least 3.5 MPa and a space velocity of up to 4 volumes of hydrocarbon oil per hour per volume of hydrocracking zone capacity,(b) removing from the top of said hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid phase comprising heavy hydrocarbons, (c) passing said mixed effluent into a hot separator vessel, (d) withdrawing from the top of the separator a gaseous stream comprising hydrogen and vaporous hydrocarbons, (e) withdrawing from the bottom of the separator a liquid stream comprising liquid hydrocarbons and particles of the coke-inhibiting additive, (f) fractionating the separated liquid stream to obtain a pitch bottom stream which boils above 495°
C., said pitch stream containing said additive particles, and an aromatic heavy gas oil fraction,(g) recycling at least part of said pitch stream containing additive particles to form part of the feedstock to the hydrocracking zone, and (h) recycling at least part of said aromatic heavy gas oil fraction to form part of the feedstock to the hydrocracking zone. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- C. which comprises;
Specification