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US 5,124,023 AGranted
Continuous removal of polynuclear aromatics from hydrocarbon recycle oil
AssigneeUnion Oil Company of California
InventorsPaula J. Bosserman, Vernon T. Taniguchi
Life of this patent
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Abstract
Fused polynuclear aromatic compounds (PNAs) are continuously removed from a recycle oil stream in a hydrocracking process. An adsorption bed removes the PNAs from the recycle oil, a desorbing reagent removes the PNAs from the bed, and a regenerating agent regenerates the bed, all steps being performed simultaneously and continuously.
Claims18
A catalytic hydrocracking process comprising:
- (A) contacting a hydrocarbon feedstock in a hydrocracking zone with added hydrogen and a hydrocracking catalyst at a temperature and pressure sufficient to give a substantial conversion to lower boiling products;
- and
- (B) condensing a hydrocarbon effluent from the hydrocracking zone and separating the condensed effluent into (i) a low boiling hydrocarbon product and (ii) an unconverted hydrocarbon oil boiling above about 650.degree. F. and containing one or more aliphatic compounds and one or more fused polynuclear aromatic compounds, the unconverted hydrocarbon oil then being fed as the feed mixture stream into a continuous chromatographic process comprising the steps of (a) simultaneously introducing a feed mixture stream, a desorbing reagent stream, and a regenerator reagent stream proximate the entrance end of an adsorbent bed, the feed stream comprising a mixture of aliphatic compounds and fused polynuclear aromatic compounds, wherein the compounds and fused polynuclear aromatic compounds, wherein the fused polynuclear aromatic compounds have a greater affinity than the aliphatic compounds for the bed, the desorbing stream comprises a liquid capable of removing the fused polynuclear aromatic compounds from the bed, and the regenerator stream comprises a gas capable of regenerating the bed, (b) moving the streams with respect to the bed, and (c) removing a first stream and a substantially separate second stream proximate the exit end of the bed, the first stream having a high concentration of aliphatic compounds with respect to the concentration of fused polynuclear aromatic compounds in the first stream and the second stream having a high concentration of fused polynuclear aromatic compounds with respect to the concentration of aliphatic compounds in the second stream.
An oil refining process comprising:
- (A) forming a liquid capable of solubilizing aromatic compounds having at least about 5 fused aromatic rings;
- and
- (B) catalytically hydrocracking a hydrocarbon feedstock by:
- (i) contacting the feedstock in a hydrocracking zone with added hydrogen and a hydrocracking catalyst at a temperature and pressure sufficient to give a substantial conversion to lower boiling products;
- and
- (ii) condensing a hydrocarbon effluent from the hydrocracking zone and separating the condensed effluent into (AA) a low boiling hydrocarbon product and (BB) an unconverted hydrocarbon oil containing one or more fused polynuclear aromatic compounds, the unconverted hydrocarbon oil then being fed as the feed mixture stream into a continuous chromatographic process comprising the steps of (a) simultaneously introducing a feed mixture stream, a desorbing reagent stream, and a regenerator reagent stream proximate the entrance end of an adsorbent bed, the feed stream comprising a mixture of aliphatic compounds and fused polynuclear aromatic compounds, wherein the compounds and fused polynuclear aromatic compounds, wherein the fused polynuclear aromatic compounds have a greater affinity than the aliphatic compounds for the bed, the desorbing stream comprises a liquid capable of removing the fused polynuclear aromatic compounds from the bed, and the regenerator stream comprises a gas capable of regenerating the bed, (b) moving the streams with respect to the bed, and (c) removing a first stream and a substantially separate second stream proximate the exit end of the bed, the first stream having a high concentration of aliphatic compounds with respect to the concentration of fused polynuclear aromatic compounds in the first stream and the second stream having a high concentration of fused polynuclear aromatic compounds with respect to the concentration of aliphatic compounds in the second stream wherein at least a portion of the solvent formed in step (A) is used as the desorbing reagent stream.
3 more elements
A catalytic hydrocracking process comprising:
- (A) contacting a hydrocarbon feedstock in a hydrocracking zone with added hydrogen and a hydrocracking catalyst at a temperature and pressure sufficient to give a substantial conversion to lower boiling products;
- (B) condensing a hydrocarbon effluent from the hydrocracking zone and separating the condensed effluent into (i) a low boiling hydrocarbon product and (ii) an unconverted hydrocarbon oil boiling above about 650.degree. F. and containing one or more aliphatic compounds and one or more fused polynuclear aromatic compounds;
- (C) simultaneously introducing the unconverted hydrocarbon oil, a desorbing reagent stream, and a regenerator reagent stream proximate the entrance end of an adsorbent bed, wherein the fused polynuclear aromatic compounds in the unconverted hydrocarbon oil have a greater affinity than the aliphatic compounds in the unconverted hydrocarbon oil for the bed, the desorbing stream comprises a liquid capable of removing the fused polynuclear aromatic compounds from the bed, and the regenerator stream comprises a gas capable of regenerating the bed;
- (D) moving the streams with respect to the bed;
- and
- (E) removing, proximate the exit end of the bed, a first stream having a high molar ratio of the aliphatic compounds to the fused polynuclear aromatic compounds and a second stream having a high molar ratio of the fused polynuclear aromatic compounds to the aliphatic compounds.
3 more elements
Dependencies are inferred from the claim text.