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 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.

Abstract: Hollow fiber membrane separation elements are improved with respect to fluid flow and contacting by dividing the bundle of hollow membrane fibers in the element into discrete sub-bundles by use of baffles in the module.

Abstract: Flux solvents and/or pitch neomesophase anti-solvents used in the generation of carbon fiber precursors from pitch are separated from mixtures of such solvent and uncoverted carbon fiber precursors by contacting said mixtures with asymmetric hydrophobic membranes under conditions of reverse osmosis. The membranes used in this separation are asymmetric polyimide membranes and asymmetric polyvinylidene fluoride membranes. Separation conditions include a contacting pressure sufficient to overcome the osmotic pressure of the solvent. The pressure is typically about 300 to 1000 psi. Contacting temperature is about 0.degree. to 100.degree. C., preferably about 20.degree. to 80.degree. C. The membrane of choice is an asymmetric polyimide membrane.

Abstract: A method is described for the production of regenerated cellulose membranes which method comprises the steps of:(a) dissolving a cellulose material to form a solution;(b) casting the cellulose solution into a film;(c) coagulating the cellulose solution film using an alkali alcoholic solution;(d) washing the coagulated cellulose film in an alcohol;(e) regenerating the cellulose film using acidic alcohol solution;(f) washing the regenerated cellulose membrane using an alcohol.The regenerated cellulose thus formed may be dried, if desired, preferably without a softener.The regenerated cellulose thus produced, when prepared in the form of a film or membrane, possesses higher flux and superior selectivity for organic liquid separation than regenerated cellulose membranes prepared employing aqueous solutions in steps b through e above and is most advantageously employed for the recovery of polar dewaxing solvents (e.g. ketones and mixed ketone/aromatic solvents) from dewaxed oil.

Abstract: A hydrocarbon dewaxing process comprising the steps of:(a) chilling the waxy hydrocarbon feed to be dewaxed in the absence of solvent to crystallize a portion of the hard wax;(b) introducing the hydrocarbon feed to be dewaxed into a centrifuge;(c) centrifuging the solvent free hydrocarbon feed thereby generating two streams, stream (I) comprising a major portion of oil with a minor portion of entrained wax, stream (II) comprising a major portion of wax with a minor portion of entrained oil;(d) adding a dewaxing solvent to stream (II) generating a slurry A;(e) feeding slurry A to a centrifuge thereby separating slurry A into an oil-solvent stream (III) and a wax-solvent stream (IV);(f) passing the oil-solvent stream (III) to a membrane separation unit wherein the stream is separated into a recycle solvent stream and an oil-solvent stream of reduced solvent content (stream V);(g) passing oil-solvent stream (V) to an oil recovery unit wherein the stream is separated into a recycle solvent stream and an oil strea