Abstract: The selectivity of a membrane pervaporation aromatics/non-aromatics separation process is unexpectedly improved by the recycle of permeate to the separation process for co-processing with fresh feed. The selectivity obtained is greater than that achieved by processing either the feed or a recycle permeate stream by itself.

Abstract: Catalyst in a slurry phase reactor is rejuvenated in said reactor using a substantially vertical draft tube fully immersed in the slurry which utilizes a rejuvenating gas injected substantially near the bottom of the substantially vertical draft tube whereby catalyst near the bottom of the slurry phase reactor is drawn up the draft tube and discharged from the top of the draft tube near the top of the slurry phase in said reactor, control over the rejuvenation temperature in the substantially vertical draft tube being achieved by means of insulating the draft tube and/or fitting the draft tube with heating or cooling means.

Abstract: Lube oil basestocks having an oil/water interfacial tension (.gamma. o/w) of less than 41 mN/m, preferably less than about 35 mN/m which exhibit unacceptable demulsibility can have their demulsibility performance improved by contacting said lube oil basestock with an acidic ion exchange resin, such as Amberlyst AR-15, or with silica. The treated lube oil base stock exhibits an oil/water interfacial tension (.gamma. o/w) of at least about 41 mN/m, preferably at least about 42 mN/m.

Abstract: An improved spiral wound element for separations is disclosed wherein the improvement comprises using as the feed/retentate space one or more layers of a material having an open cross-sectional area in the range 30 to 70% and as the permeate spacer material at least three layers of material two of which are fine and have an open cross-sectional area of about 10 to 50% surrounding a coarse layer having an open cross-sectional area of about 50 to 90%.

Abstract: An apparatus and method for removing particles from refinery fluid hydrocarbon and organic streams comprising an elongated housing containing multiple layers of non-woven fabric arranged in said housing as discrete stratified layer array of filter fabric of increasing particle retentive power thus arranged in the housing in the direction of fluid flow. The fabric layer comprise thermally stable materials of different permeability which are mineral coated to provide structural, fluid compression resistance, and to which flint or talc particles are added to impact surface roughness to the fibers. A final layer of uncoated needled felt fine fabrics end caps the array. In operation the refinery fluid is passed through the filter array such that the direction of fluid flow is in the direction of increasing retentive power of the filter fabric array.

Abstract: Catalyst in a slurry phase reactor is rejuvenated and uniformly distributed in said reactor using a substantially vertical draft tube fully immersed in the slurry which utilizes a rejuvenating gas injected substantially near the bottom of the substantially vertical draft tube whereby catalyst near the bottom of the slurry phase reactor is drawn up the draft tube and discharged from the top of the draft tube near the top of the slurry phase in said reactor.

Abstract: Catalyst which has become deactivated during a hydrocarbon synthesis (HCS) process is reactivated - rejuvenated using an external reactivation - rejuvenation vessel resulting in a multiple HCS reaction - catalyst rejuvenation reactor vessel design. Flow of the catalyst is synthesis product slurry from the reactor vessel to the rejuvenation vessel and the flow of rejuvenated catalyst back to the reactor vessel are driven by gravity only.

Abstract: This invention relates to a method for ultrafiltering heavy hydrocarbons containing detrimental qualities of metals and CCR, said method comprising feeding the heavy hydrocarbons to a first ultrafiltration stage wherein the feed is contacted with an ultrafiltration membrane thereby producing a first permeate and a first retentate and feeding the first permeate to a second ultrafiltration stage wherein the first permeate is contacted with an ultrafiltration membrane which is the same as the ultrafiltration membrane in the first ultrafiltration stage to recover a second permeate of significantly reduced metals and CCR content and a second retentate. The second permeate can be sent to subsequent ultrafiltration stages utilizing the same membrane with permeate from each such stage being used as feed to the next subsequent downstream stage.

Abstract: Straight run hydrocarbon distillate streams containing low concentrations of 2-ring aromatics can be processed to remove a high percentage of the 2-ring aromatics by contacting said stream with one side of a polyester imide membrane under pervaporation conditions to produce a permeate stream containing a very high percentage of 2-ring aromatics and a retentate stream of severely reduced 2-ring aromatic content.

Abstract: Catalyst particle distribution and mixing in slurry part of bubble columns is improved by introducing a secondary suspending fluid into the columns at locations within the lower 20% of the vertical height of the column but above the gas distributor normally located at or near the bottom of the columns.

Abstract: A multi-element housing is disclosed for the containment of multiple membrane separation elements in parallel. The multi-element housing is characterized in that the elements are grouped in parallel with a feed/retentate zone, defined by a space enclosed by two tube sheets arranged at the same end of the elements. The central mandrels of the elements pass through the feed/retentate zone space defined by the two tube sheets and empty permeate outside the defined space into a permeate collection zone from which it is removed, while the tube sheet directly attached to the element is in open relationship to the interior of the membrane element and retentate accumulates in the space between the top tube sheet and the bottom tube sheet from which it is removed.

Abstract: The solvent extraction of aromatics containing oil using a selective aromatics extraction solvent to produce an aromatics rich extract phase and an oil rich/aromatics lean raffinate is improved by the steps of subjecting the extract phase to a membrane separation step to produce a permeate phase and a retentate phase passing the retentate phase to a settling zone wherein the retentate phase spontaneously separates into two liquid phases, and recycling the upper phase to the extraction zone, either to the feed inlet or to the bottom of the extract reflux zone to thereby increase the raffinate oil recovered from the extraction tower. Alternatively or in addition to the above, a side stream can be taken from an intermediate zone of the extraction zone (e.g. extraction tower) and fed to a membrane separation to produce a solvent rich permeate and an oil rich retentate.

Abstract: A hollow fiber permeator is described which permits counter-current flow in the passage of feed/retentate and permeate-sweep streams. The permeator comprises a bundle of hollow fibers compartmentalized using a series of concentric shells or a spiral wrap extending the entire length of the hollow fibers. The rings or spiral wrap are perforated along the top and bottom to permit even flow distribution through each of the compartments defined by the concentric rings or spiral wrap so that the linear flow rate down the length of the permeator is similar for each compartment.

Abstract: The present invention is a process for the recovery of normal alcohols, especially C.sub.1 -C.sub.20 n-alcohols, preferably n-C.sub.4 -C.sub.14 alcohols, most preferably n-C.sub.6 -C.sub.11 alcohols from n-paraffins by means of pervaporation through a membrane. The alcohols/paraffin feed mixture may be that produced in the Fischer-Tropsch synthesis process wherein mixtures of CO and H.sub.2 are reacted to produce paraffin waxes and a minor but still valuable amount of alcohols.

Abstract: The present invention is directed to a multi-block polymeric material comprising an ester 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 materials especially membranes comprising thin, dense films of said multi-block polymeric material deposited on a microporous support later producing a thin film composite membrane.

Abstract: Hydrocarbon dewaxing using propane or other autorefrigerative dewaxing solvent can be practiced in a centrifuge wherein the centrifugal force generated in the centrifuge produces a pressure gradient permitting dewaxing to be practiced on a continuous basis.

Abstract: Organic non-quaternary clathrate salts are useful for separating hydrocarbon feed streams into aromatics rich fraction and aromatics lean fraction. The organic non-quaternary clathrate salts are characterized by having cations containing less than 16 carbon atoms. Preferred salts are collidinium triflate and triethylammonium dihydroxybenzoate.

Abstract: The isomerization activity of hydroisomerization catalyst is recovered by subjecting the catalyst to a wash using light aromatic solvents at elevated temperature, e.g. toluene at 300.degree. C. This hot aromatic solvent wash may be preceded by a hot hydrogen containing gas strip. Catalyst activity can be maintained by the continuous or periodic addition of light aromatic solvent or light aromatic containing materials to the feeds sent to the isomerization catalyst.

Abstract: A catalyst is disclosed comprising a thin outer shell of catalytic material bonded to an inner core of catalytically inert material. The catalyst is made by coating a catalytically inert core such as alpha alumina, with a thin layer of finely divided catalytically active material in a slurry of colloidal boehmite/pseudo boehmite then calcining to convert the boehmite/pseudo boehmite into .gamma. alumina thereby bonding it to the inert core. Catalysts made by this technique containing an outer shell of platinum on fluorided alumina in an inert core of alpha alumina .gamma. are attractive isomerization catalysts.

Abstract: A method for producing large diameter hollow fiber membrane modules and the modules made by the method are disclosed. The method involves the production of sub assemblies comprising a central assembly and a number of concentric ring assemblies which fit around each other and the central assemble. These sub assemblies, when fitted together can then be potted or glued and permitted to set.