Abstract: The separation of aromatic hydrocarbons from mixtures of aromatic and non-aromatic hydrocarbon feeds under pervaporation conditions, is improved by the control of the amount of oxygen present in the feed. The amount of oxygen in the feed, such as heavy cat naphtha or other cracked feed, should be less than 30 wppm, preferably less than 10 wppm. The oxygen level in the feed can be controlled by the addition of small amount of oxygen scavenger into the feed. Hindered phenols are representative of useful oxygen scavengers.

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: Mixtures of light and heavy waxes are fractionated by permeation through a porous membrane at temperatures just above the cloud point of the mixture with the heavier, higher melting point waxes being the component of the mixture which selectively permeates through the porous membrane.

Abstract: The present invention is directed to non-porous isocyanurate-crosslinked polyurethane membranes. These membranes are useful for the separation of aromatic hydrocarbons from non-aromatic hydrocarbons. The separation can be performed using any commonly accepted membrane separation technique, e.g. reverse osmosis, dialysis, pervaporation or perstraction but is preferably performed under pervaporation or perstraction conditions.

Abstract: A new membrane for the separation of aromatic hydrocarbons from mixtures of said aromatic hydrocarbons and non-aromatic hydrocarbons has been prepared comprising a highly aromatic polyurethane membrane. These highly aromatic polyurea/urethane membranes are symmetric, dense film membranes made from the corresponding polyurea/urethane copolymers by standard membrane casting techniques. The polyurea/urethane copolymers are produced by reacting dihydroxy or polyhydroxy compounds, such as polyethers or polyesters having molecular weights in the range of about 500 to 5000 with aliphatic, alkylaromatic or aromatic diisocyanates or polyisocyanates and low molecular weight chain extenders, such as diamines, polyamines or amino alcohols.

Abstract: Slack waxes and synthetic wax are isomerized and processed into high viscosity index and very low pour point lube base stock oils and blending stocks by the process comprising the steps of hydrotreating the wax, if necessary, to remove heteroatom and polynuclear aromatic compounds and/or deoiling the wax, if necessary, to an oil content between about 5-20% oil, isomerizing the wax over a Group VI-Group VIII on halogenated refractory metal oxide support catalyst, said isomerization being conducted to a level of conversion such that .about.40% and less unconverted wax remains in the 330.degree. C..sup.+, preferably the 370.degree. C..sup.+ fraction sent to the dewaxer. The total isomerate from the isomerization unit is fractionated into a lube oil fraction boiling at 330.degree. C..sup.+, preferably 370.degree.p9 C..sup.+. This oil fraction is solvent dewaxed preferably using MEK/MIBK at 20/80 ratio and unconverted wax is recycled to the isomerization unit.

Abstract: A new membrane for the separation of aromatic hydrocarbons from mixtures of said aromatic hydrocarbons and non-aromatic hydrocarbons has been prepared comprising a highly aromatic polyurea/urethane membrane. These highly aromatic polyurea/urethane membranes are symmetric, dense film membranes made from the corresponding polyurea/urethane copolymers by standard membrane casting techniques. The polyurea/urethane copolymers are produced by reacting dihydroxy or polyhydroxy compounds, such as polyethers or polyesters having molecular weights in the range of about 500 to 5000 with aliphatic, alkylaromatic or aromatic diisocyanates or polyisocyanates and low molecular weight chain extenders, such as diamines, polyamines or amino alcohols.

Abstract: The present invention is directed to a multi-block polymeric material comprising a first prepolymer, made by combining epoxy with diamine, chain extended with a second, different compatible prepolymer selected from the group of prepolymers comprising (a) and (A) diisocyanate combined with a monomer selected from (B) epoxy, polyester, dianhydride or its corresponding tetraacid or diacid-diester, and diamaine in an A/B mole ratio ranging from about 2.0 to 1.05, (b) an (A) polyester combined with (B) epoxy, in an A/B mole ratio ranging from a bout 2.0 to 1.05, (c) an (A) dianhydride or its corresponding tetraacid or diacid-diester combined with one mole of a monomer selected from (B) epoxy, diisocyanate, polyester, and diamine in an A/B mole ratio ranging from about 2.0 to 1.05, and (d) an (A) diamine combined with a monomer selected from (B) diisocyanate and dianhydride or its corresponding tetraacid or diacid-diester in an A/B mole ratio ranging from about 2.0 to 1.05, and mixtures thereof.

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: Supported thin film membranes of polyurethane, polyurea/urethane, polyurea/polyurethane alloy blends are prepared by depositing a solution of the appropriate polymer on a microporous hydrophobic support. The solution wets but does not soak through the hydrophobic support because the amounts and ratios of solvents and surfactant used to produce the solution have been adjusted to produce a solution having optimum coating properties (for example, surface tension, solvency, viscosity). The solvent of the solution comprises a mixture of a low surface tension solvent and a high solvency solvent. The polymer solution is optionally aged at least 1 day prior to being coated on the microporous support.

Abstract: The present invention is directed to a process of using a multi-block polymeric material comprising a urea prepolymer chain extended with a second compatible prepolymer selected from the group of prepolymers comprising (a) an (A) dianhydride or its corresponding tetraacid or diacid-diester combined with a monomer selected from (B) epoxy, diisocyanate, polyester, and diamine in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.1, and (b) an (A) diamine combined with a monomer selected from (B) epoxy and dianhydride or its corresponding tetraacid or diacid-diester in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.1, and mixtures thereof.

Abstract: The present invention is directed to a multi-block polymeric material comprising an imide prepolymer chain extended with a second, different, compatible prepolymer selected from the group of prepolymers comprising (a) an (A) dianhydride or its corresponding tetraacid or diacid - diester combined with a monomer selected from (B) epoxy, diisocyanate, polyester and diamine in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.1 and (b) an (A) diamine combined with a monomer selected from (B) epoxy, diisocyanate and dianhydride or its corresponding tetraacid or diacid - diester in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.1, and mixtures thereof. The present invention is also directed to membranes of the above recited multi-block, polymeric material, especially membranes compising thin, dense films of said multi-block polymeric material deposited on a microporous support layer producing a thin film composite membrane.

Abstract: A multi-block polymer comprising an oxazolidone prepolymer chain extended with a second compatible prepolymer, the membrane made therefrom and the use of said membrane in aromatics/non-aromatics separations is disclosed. The multi-block polymer comprises an oxazolidone containing prepolymer chain extended with a second compatible prepolymer, said second prepolymer selected from the group of prepolymers produced by combining (a) and (A) diisocyanate with a monomer selected from (B) polyester dianhydride or corresponding tetraacid or diacid-diester, and diamine in an A/B mole ratio ranging from about 2.0 to 1.05, preferably 2.0 to 1.1; (b) an (A) dianhydride or its corresponding tetraacid or diacid-diester with a monomer selected from (B) epoxy, diisocyanate, polyester and diamine in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.

Abstract: Thin film membranes of polyurea, polyureapolyurethane alloy, polyurea-polyurea/urethane alloy or polyurea/urethane are prepared by deposition of a thin film of suspension of the selected polymer on a thick permeable support layer by the technique of preparing a suspension of the selected polymer in a solvent which does not dissolve the thick permeable support layer and permitting the solvent to evaporate and/or permeate through the thick-permeable layer.

Abstract: Claus tail-gas containing H.sub.2 S and SO.sub.2 in a mol ratio of 2:1 is passed in contact with a catalyst-adsorbent bed (19A) at a temperature of 135.degree. to 150.degree. C. and a space velocity of 50 to 1500 h.sup.-1 whereby elemental sulfur produced by the reaction of H.sub.2 S and SO.sub.2 is deposited upon and/or adsorbed on said bed. The resulting sulfurous gas mixture is cooled by indirect heat exchange (26) to a temperature of 120.degree. to 135.degree. C. and liquid elemental sulfur is recovered (27,54,55,101) the sulfurous gas (28) thereafter being cooled and diluted by adding cool inert gas (34) thereto to maintain the water partial pressure below the saturation vapor pressure, and the cooled diluted gas mixture is contacted with a bed of catalyst-adsorbent (32A) at a temperature of 90.degree. to 125.degree. C. whereby further elemental sulfur is produced by the reaction of SO.sub.2 and H.sub.2 S.

Abstract: Waxy distillates, or raffinates containing from as little as 10% wax but more typically about 30% wax or more are upgraded by a process comprising the steps of hydrotreating the waxy oil under conditions which convert less than 20% of the feed into products boiling lower than the feed to reduce the sulfur and nitrogen content of the oil followed by hydroisomerizing the hydrotreated waxy oil to reduce the wax content and increase the viscosity index. This oil having a waxy content of less than 30%, preferably less than 25%, can now be more easily dewaxed using conventional solvent dewaxing procedures. The advantage of the present process resides in the increased yield and/or stability of oil as compared to other upgrading, dewaxing processes which convert wax to light products. The isomerization catalyst is preferably a low fluorine content catalyst, more preferably a noble metal on 0.1 to less than 2 wt % fluorine on alumina catalyst, most preferably a noble Group VIII metal (e.g.

Abstract: The present invention is directed to non-porous isocyanurate-crosslinked polyurethane membranes. These membranes are useful for the separation of aromatic hydrocarbons from non-aromatic hydrocarbons. The separation can be performed using any commonly accepted membrane separation technique, e.g. reverse osmosis, dialysis, pervaporation or perstraction but is preferably performed under pervaporation or perstraction conditions.

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: Polyimide ultrafiltration membranes made using a single solvent and containing a pore forming agent have been produced and have been found to be useful for recovering dewaxing aid used in dewaxing process.

Abstract: Improved separation of feed streams containing multiple components is effected by means of a multi membrane staged pervaporation process wherein each membrane stage is series is run as progressively higher temperature, stronger vacuum or both than the preceding stage. This process is especially useful for separating components from wide boiling range mixtures.