Recovery of aromatic hydrocarbons using lubricating oil conditioned membranes
AssigneeExxon Mobil Corporation
InventorsArthur A. Chin, Bryan M. Knickerbocker, Jeffrey C. Trewella, Terry R. Waldron, Lloyd S. White
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Abstract
Permselective separation of aromatic hydrocarbons from non-aromatic hydrocarbons in a feed stream is accomplished using improved asymmetric membranes. The preferred membranes are fashioned from a polyimide and conditioned with a lubricating oil. Feed streams containing a mixture of aromatic and non-aromatic hydrocarbons are contacted with the dense active layer side of the polyimide membrane under a pressure and temperature sufficient to selectively permeate the desired aromatic hydrocarbon.
Claims30
A method of separating aromatic hydrocarbons from non-aromatic hydrocarbons in a feed stream, the method comprising contacting a liquid feed stream containing a mixture of aromatic and non-aromatic hydrocarbons with a dense active layer of an asymmetric polyimide membrane, which membrane has been treated with a conditioning agent comprising a lubricating oil.
A method of improving the feed quality to an aromatic separation or aromatic conversion process comprising separating non-aromatic compounds from aromatic hydrocarbons in an aromatic hydrocarbon-containing feed stream by selectively permeating at least a portion of said aromatic hydrocarbons contained in said feed stream through a permselective, asymmetric Polyimide membrane under hyperfiltration conditions and diverting a primarily non-aromatic retentate out of the feed stream, wherein said membrane has been treated with a conditioning agent comprising a lubricating oil.
A method of improving feed quality to a non-aromatic hydrocarbon processing unit which would benefit from low concentration levels of aromatic hydrocarbons in said feed comprising separating aromatic hydrocarbons from non-aromatic hydrocarbons in an aromatic-containing feed stream by selectively permeating at least a portion of said aromatic hydrocarbons through a permselective, asymmetric polyimide membrane under hyperfiltration conditions and sending a retentate enriched in non-aromatic hydrocarbons to said non-aromatic processing unit.
A method of improving the feed quality to an aromatic separation or conversion process comprising
- separating non-aromatic compounds from aromatic compounds in an aromatic hydrocarbon-containing feedstream by selectively permeating at least a portion of the aromatic hydrocarbons contained in the feedstream through a permselective membrane and diverting a primarily non-aromatic retentate off of the feedstream, wherein the membrane is an asymmetric polyimide membrane which has been treated with a conditioning agent comprising a lubricating oil.
An aromatics conversion process comprising the steps of:
- a) passing a fresh aromatics-rich feedstream to a permselective, asymmetric polyimide membrane under hyperfiltration conditions wherein the feedstream is separated into an aromatics-enriched permeate and an aromatics-lean retentate, which membrane has been treated with a conditioning agent comprising a lubricating oil;
- b) purging said retentate and passing the permeate to an aromatics conversion zone under conversion conditions;
- c) passing the conversion zone product effluent stream to a product separation zone to recover converted aromatic product and a stream comprising unconverted aromatics;
- and
- d) recycling the unconverted aromatics to the aromatics conversion zone.
Dependencies are inferred from the claim text.