Abstract: The yield and quality of products secured from cracking units is increased by the process of subjecting the product stream secured from such cracking unit to a selective aromatics removal process and recycling the recovered aromatics lean (saturates rich) stream to the cracking unit whereby such saturates rich stream is subjected to increased conversion to higher value desired products.

Abstract: Raffinate yield from solvent extraction is improved when the extract phase recovered from the solvent extraction process is subjected to a membrane separation step wherein a saturates/1-ring aromatics rich retentate is produced and a 2+ ring aromatics rich permeate are produced and the saturates/1-ring aromatic rich retentate phase is recycled to the solvent extraction process.

Abstract: Olefins are selectively separated from hydrocarbon feeds containing mixtures of olefins and paraffins by contacting said hydrocarbon feed mixture with one side of a micro-porous, non-selective partition barrier membrane while simultaneously passing, preferably in countercurrent flow, along the opposite side of said membrane a polar solvent. The olefin preferentially passes through said micro-porous non selective partition barrier in response to the polar solvent yielding a permeate enriched in olefin and a retentate enriched in paraffin as compared to the original feed stream.

Abstract: Naphthenic hydrocarbons are separated from aliphatic rich hydrocarbon feeds comprising mixtures of naphthenes with paraffinic hydrocarbons by a membrane extraction process whereby the hydrocarbon feed is contacted with one face of a porous, non-selective partition barrier membrane while simultaneously contacting the other side of said membrane with a polar solvent such as ethylenediamine. The naphthenic hydrocarbon preferentially migrates through the porous membrane partition barrier in response to the polar solvent present on the permeate side of the barrier.

Abstract: Non-normal, branched paraffins (isoparaffins) are separated from hydrocarbon feeds comprising mixtures of isoparaffins and normal paraffins by the procedure involving the steps of contacting the hydrocarbon feed with one face of a non-selective, microporous partition barrier membrane while simultaneously contacting the opposite face of said membrane, preferably in countercurrent flow, with a polar solvent. The isoparaffins in the feed selectively permeate across the porous partition barrier membrane in response to the polar solvent to the solvent side of the membrane whereby a permeate enriched in isoparaffins and a retentate of decreased isoparaffin content as compared to the feed are obtained.

Abstract: The yield, raffinate product quality, and throughput of the selective solvent extraction of hydrocarbon feeds is improved by subjecting the hydrocarbon feeds from which aromatic hydrocarbons are to be selectively solvent extracted to a membrane separation process which selectively permeates aromatics through the membranes to produce a permeate rich in aromatics and a retentate rich in saturates and 1-ring aromatics and subjecting this retentate to the selective solvent extraction process.

Abstract: Multi-ring aromatic hydrocarbons and/or toxins are selectively solvent extracted from hydocarbon feed streams by the process comprising contacting the aromatics and/or toxins containing hydrocarbon stream with one side of a porous, non-selective partition barrier membrane while simultaneously contacting the other side of said membrane with an aromatics selective extraction solvent whereby the multi-ring aromatic hydrocarbons and/or toxins selectively migrate through the porous partition barrier membrane in response to the selective solvent. A preferred extraction solvent is ethylenediamine. The permeate comprising multi-ring aromatics in solvent can be subjected to a membrane separation process to separate the extraction solvent from the aromatics.

Abstract: A method for separating mixtures into a first fraction and a second fraction employing a combination of settling, ultrafiltration and permeate/retentate recycle to the settling zone is disclosed. A multi component feed stream is fed to a settling zone wherein it is permitted to separate into two major phases. At the interface of these two phases is an intermediate zone which is relatively equal in concentration of the component in the feed. A slip stream is drawn from the settling zone at this intermediate zone and fed to a membrane separation unit wherein the slip stream is separated into a retentate enriched in one component and a permeate enriched in the other component. The retentate is fed back to the settling zone to an area therein which has a high concentration of the component present in the retentate. The permeate is fed to the settling zone to an area therein which has a high concentration of the component present in the permeate.

Abstract: Surfactants present in water/oil/surfactant emulsions can be selectively separated from the emulsions by practicing an ultrafiltration process under specific conditions of pressure and ultrafiltration membrane pore size. It has been discovered that increasing the applied pressure results in an increase in the permeability of the surfactant without a commensurate increase in the permeability of the water or oil.