Abstract: A crude aqueous mixture of basic salts of an organic acid, free organic acid, and impurities is mixed with carbon dioxide under pressure and applied to a membrane such as a reverse osmosis or other membrane with small pores while holding the mixture under pressure with well mixed carbon dioxide, such that the free organic acid preferentially permeates the membrane while the impurities and salts of the organic,acid are preferentially but not necessarily completely retained. In The preferred form of the invention a back pressure is maintained on the permeate side of the membrane that is a significant pressure but less than the pressure applied to the feed side. This allows higher levels of acidification to be achieved. This is necessary as many membranes are permeable to CO.sub.2 choices of membrane permeate side pressure, retentate side pressure, and permeate counter flow rate can be used to effect different levels of either purification or concentration or both.

Abstract: A method for continuously preparing a sterile culture medium comprises combining separate unsterilized fluid components in separate streams into a single mainstream. The mainstream is applied to a transverse flow filtration module having a membrane which separates the mainstream into a permeate and a retentate. The permeate is fed to a bioreactor and the retentate is diverted to a centrifuge to precipitate contaminants. The clarified retentate is returned into the mainstream upstream of the transverse flow filtration module.

Abstract: A polyester is provided which facilitates the separation of blood into light and heavy phases via centrifugation in a blood collection vessel. The polyester is useful as a component of a partitioning composition formulated to have appropriate specific gravity to be positioned intermediate the light and heavy blood phases during centrifugation. A partitioning composition including a polyester of the invention provides a particular advantage in blood collection vessels due to its lighter and more consistent coloration. The polyester composition can be prepared with relative ease compared to prior art polyesters useful in blood partitioning compositions.

Abstract: A process for solvent dewaxing petroleum feedstock to separate crystallized wax from lubricant oil by filtration of a wax/oil/solvent mixture. The feedstock is sequentially cooled and mixed with cold polar solvent to form a wax crystal phase and oil-solvent phase, and-the oil-solvent filtrate stream is contacted with solvent permeable selective membrane at low temperature to recover an internal circulating permeate solvent stream and an oil-rich retentate stream containing dewaxed oil product and residual solvent. Improved operation is achieved by splitting the internal circulating solvent stream into a multiple cold solvent recycle streams and injecting a plurality of the cold solvent recycle streams into the waxy petroleum feedstock during sequential cooling and mixing. By initially injecting a cold recycle solvent stream in to the waxy petroleum feedstock at a small temperature differential near the wax crystallization temperature, shock cooling and excess small wax crystal formation is avoided.

Abstract: A method for recovering carboxylic acids from a dilute aqueous solution thereof having a concentration below about ten percent (10%) by weight, which includes passing the dilute acid solution through a reverse osmosis separator, thereby producing a permeate substantially free of acid and a retentate having an acid concentration above about ten percent (10%) by weight. The retentate is contacted with a liquid extractant for acids to produce an acid-rich extractate and an acid-free raffinate. The acid is then recovered from the acid-rich extractate.

Abstract: A method for producing an aqueous solution of an aminocarboxylic acid from an aqueous solution of an alkali metal salt of the aminocarboxylic acid is disclosed. The first step of the method is to adjust the pH of the aqueous solution of the alkali metal salt of the aminocarboxylic acid to between about 1.0 and about 3.0. This is done by adding a monovalent inorganic acid to the aqueous solution of the alkali metal salt of the aminocarboxylic acid to form an aqueous feed solution containing protonated aminocarboxylic acid and an inorganic alkali salt having an inorganic anion and an alkali metal cation. The second step of the method is to pass the aqueous feed solution through at least one membrane using a diafiltration process to separate the aqueous feed solution into an aqueous permeate solution, containing the alkali metal cation, and an aqueous retentate solution containing the aminocarboxylic acid.

Abstract: The intention is a process for removing inorganic salts from aqueous mixtures of organic compositions capable of forming micelles. The aqueous mixture is subjected to ultrafiltration to remove the inorganic salts and recover the organic compositions in the retentate.

Abstract: In a process for purifying an aqueous liquid reaction and/or washing medium containing i) hot water-insoluble cellulose ethers and ii) hot water-soluble cellulose ethers and/or macromolecular cellulose ether by-products, in a purification step a) the aqueous medium has a temperature above the gel point of the hot water-insoluble cellulose ether and gelled cellulose ether is separated from the aqueous medium by means of a solid-bowl centrifuge or a plate separator and in a purification step b) the remaining aqueous liquor is treated by ultrafiltration at a concentration ratio of at least 40.

Abstract: A filter and process of using the filter for the filtration of liquor cerebrospinalis, the filter has a membrane filter layer having a pore size of from 0.04-0.45 .mu.m a thickness of 0.1 to 1 mm, a geometric surface area of from 15-300 cm2, and a separation capacity of at least 500 .mu.g.

Abstract: The invention relates to a microfiltration and/or ultrafiltration membrane consisting of a polymer having nominal pores of 0.001-10 .mu.m. The special feature of the membranes according to the invention is that the matrix of the membrane incorporates an active adsorbent which is preferably polyvinyl pyrrolidone. Usually the polyvinyl polypyrrolidon is present in the membrane in an amount of 5-90% by weight and preferably in an amount of 30-70% by weight. Preferably the membrane is hydrophilic and is usually asymmetric or is constructed of different layers. The nominal pore size of the membrane is 0N05--5 .mu.m and preferably 0.2-1.0 .mu.m, while the membrane is tubular, flat or capillary.

Abstract: This invention relates to the preparation of, and a device for using, a permanently deformed sulfonated halopolymer article. A flexible and non-brittle flange may be formed from at least one end of a hollow perfluorosulfonic acid membrane in one aspect of the invention. The flanged membrane is particularly useful for quick attachment and detachment to various instrumentation used for pervaporation. In addition, by packing the membrane with a means for increasing radial diffusion of fluid within the membrane, pervaporation efficiency may be increased.

Abstract: An improved asymmetric membrane fashioned from a polyimide for the liquid separation of solvents from lube oil. The membrane is based on a fully imidized polymer based on 5(6)-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane polymer and benzophenone tetracarboxylic dianhydride.

Abstract: Disclosed is a filter medium for treating a blood material selected from the group consisting of a leukocyte-containing suspension and plasma, comprising a polymeric, porous element having, in a surface portion thereof, a negative charge and having a surface electric charge of not smaller than -30 .mu.eq/g of the polymeric, porous element. The filter medium and an apparatus having the filter medium packed in a casing having an inlet and an outlet, can be advantageously used for treating a blood material, for example, for separating leukocytes from a leukocyte-containing suspension including whole blood, for blood dialysis or for removing undesired proteinous substances and the like from whole blood or plasma by adsorption-filtration, while effectively controlling a concentration of bradykinin (which is causative of anaphylactic reactions) in a treated blood to a level not exceeding 4,000 pg/ml.

Abstract: An insoluble material for adsorbing a pyrogen comprising a polymer of an aziridine compound. According to the present invention, a large mount of the pyrogen can be easily removed from a solution containing pyrogen, and a large amount of the material for adsporbing the pyrogen can be prepared in easy steps. Therefore, the adsorbing material can greatly contribute to the preparation of medicines.

Abstract: A secondary polishing process for Bayer Process liquors suspension is described. The polishing process uses a combination of bio-polymers, particularly such bio-carbohydrates as dextran, with an inert insoluble solid, such as a filter aid, to treat the primary red mud settler overflow, then clarifying these treated overflow liquors in a secondary clarifier. Results provide for from 0-20 milligrams per liter suspended solids, often from 0-5 ppm suspended solids, and may make sand filter or Kelly filter operation an option in the Bayer Process.

Abstract: A process for solvent dewaxing a waxy oil feed to obtain petroleum oil lubricating stock comprising the steps of contacting a warm waxy oil feed by indirect heat exchange first with cold filtrate, then with refrigerant to crystallize and precipitate the wax in the oil feed to form an oil/solvent/wax mixture. The oil/solvent/wax mixture is diluted with cold solvent to adjust the viscosity of the mixture and the mixture is fed to a filter which filters and removes the wax from the cold oil/solvent/wax mixture. A cold wax cake is recovered and a cold oil/solvent filtrate stream is recovered. The cold oil/solvent filtrate stream is fed, at the filtration temperature, to a selective permeable membrane. The membrane selectively separates the cold filtrate into a cold solvent permeate stream and a cold filtrate stream which contains the dewaxed oil and the remaining solvent. The cold solvent permeate stream at the filtration temperature is recycled to the filter feed stream.

Abstract: A process for solvent dewaxing a waxy oil feed to produce a lubricating oil by contacting a warm waxy oil feed in counter-current with a cold oil/solvent filtrate stream through a selectively permeable membrane to transfer cold solvent through the membrane to the feed and simultaneously cool the feed, dilute it with solvent and separate solvent from the cold oil/solvent filtrate stream. The cooled, diluted feed stream is then further cooled to precipitate the wax to form an oil/solvent/wax mixture which is further diluted with cold solvent and filtered to remove wax. The cold oil/solvent filtrate stream is cycled to the selectively permeable membrane for the counter-current contact with the warm waxy oil feed and, after removal of a portion of the solvent over the membrane, is sent to an oil/solvent separation operation in which the solvent is removed from the dewaxed oil.

Abstract: Disclosed is a process for separating metal catalysts based on ammonium and phosphonium phosphotungstates from reaction mixtures in which they are dissolved. The process is based on the use of semipermeable membranes and has found an useful application in the separation of the above said catalysts from mixtures obtained from alkenes and soybean oil epoxidation.

Abstract: A water purification process for removing dissolved solids of the type that are normally present in a municipal water supply or the like. The process uses a forced draft decarbonator having an inlet and a product outlet, a vacuum degasifier having an inlet, a product outlet and a water level sensor, and a reverse osmosis unit having an inlet, a product outlet and a brine outlet. Preferably, the vacuum degasifier is located downstream of the forced draft decarbonator with the product outlet of the forced draft decarbonator being coupled to the inlet of the vacuum degasifier. The reverse osmosis unit is located downstream of the vacuum degasifier with the product outlet of the vacuum degasifier being coupled to the inlet of the reverse osmosis unit. Water to be purified is provided to the inlet of the forced draft decarbonator at a predetermined rate.

Abstract: A semi-permeable composite with a porous substrate having a polymer network obtained by interfacial polymerization of a reactive polyfunctional monomer having reactive groups --NHR. (R.sub.1 is H or a C.sub.1 -C.sub.20 alkyl groups), --OH or --SH and a reactive polyfunctional material having --NCO reactive groups built from a polyalkylene oxide with terminal --OH groups and a polyisocyanate, and a process for separating components in an organic liquid medium by using said composite.

Abstract: A method of preparing hydrofluoric acid of high purity at the point of use by causing molecular diffusion of hydrogen fluoride into ultrapure water through a resin membrane. The high-purity acid is available at the site of use free of contamination that would occur during transport from a site of preparation.

Abstract: The composite membrane is disclosed having a microporous support which is coated with an aqueous polyeurethane dispersion composition wherein the microporous support is surface treated. A process for making and a process for using the membrane is also disclosed.

Abstract: The present invention is directed to a polyester/amide membrane, its preparation and its use for organic liquid separation. The polyester/amide membrane is made by reacting a dianhydride with a polyester diol in a 2:1 to 1.05:1 mole ratio to end cap the diol to produce a prepolymer which is reacted with excess thionyl chloride to convert all of the unreacted anhydride and all carboxylic acid groups to acid chloride groups. The resulting acid chloride derivative is dissolved in organic solvent and interfacially reacted with a diamine dissolved in an aqueous solvent. The excess solutions are removed and the resulting thin film membrane is dried. The membranes are useful for organic liquid separations, especially the separation of aromatic hydrocarbons from mixtures of same with non-aromatic hydrocarbons, preferably under perstraction or pervaporation conditions.

Abstract: A filter medium comprising a microporous polyvinylidene fluoride membrane and a polymer containing positively charged quaternary ammonium groups covalently bonded to the membrane, and a method of using the filter medium to treat a composition, particularly a biological or pharmaceutical composition such as an ophthalmic composition.

Abstract: Membrane separation process is improved by use, as a support membrane, of (i) a polyacrylonitrile membrane on which at least a portion of the surface --CN groups have been hydrolyzed to --COOH groups or (ii) a membrane formed of polyacrylonitrile and polyacrylic acid.

Abstract: A PVDF membrane exposed to a quarternary ammonium hydroxide solution retains it hydrophobicity and resistance to corrosive environments, yet spontaneously and completely wets with concentrated sulfuric and nitric acids. The modified membrane is incorporated into filtration devices that are in situ integrity testable in concentrated inorganic mineral acids.

Abstract: Semipermeable composite membrane, with a porous carrier substrate, whereby said carrier substrate is provided with a polymer network obtained by polycondensation, especially interfacial polymerization, which is built up of at least one reactive polyfunctional monomer or oligomer or prepolymer or polymer, and at least one acid halide containing polymer.The specialty of this semi-permeable composite membrane consists therein that the acid halide containing polymere itself is built up of one or more vinyl containing monomers.The acid halide containing polymer is generally a copolymer of acryloylchloride H.sub.2 C.dbd.CHCOCl or methacryloyl chloride H.sub.2 C.dbd.C(CH13)COCl with one or more vinyl containing monomers.Usually the vinyl containing monomer is an acrylate or an acrylamide or a mixture thereof.

Abstract: A modified porous membrane can be prepared by dissolving an aromatic polymer having a thioether group in an organic solvent, forming membrane of the aromatic polymer from the resultant solution by phase conversion and oxidizing the formed membrane. This modified porous membrane can effectively be utilized in a filtration method wherein ultrafiltration, reverse osmosis, fine filtration, gas separation, vapor permeation or pervaporation is conducted.

Abstract: A semipermeable membrane suitable for reverse osmosis applications is prepared by interfacially reacting on a support an aromatic polyamine containing at least three and, preferably, four aromatic nuclei with a polyfunctional amine-reactive compound such as an aromatic polyacyl halide.

Abstract: A composite membrane comprises a substrate made from a polymer selected from copolymers and homopolymers of ethylenically unsaturated nitriles, which substrate has preferably first been treated with a pore protector in absence of curing agents and catalysts therefor, prior to applying as the final coating a silicone layer, which is crosslinked. The pore protector, which may be, for example, a hydroxy-terminated polysiloxane, particularly a silanol-terminated polysiloxane, serves the dual purpose of preventing the pores from collapsing, when the support is dried during the curing of the silicone layer, and of preventing passage of the coating material deeply into the pores and thus also preventing an undue reduction of the flux of the finished coated membrane. Such composite membranes include solvent stable membranes which swell to an extent of no more than about 10% when immersed in various organic solvents, and their mixtures with each other and/or water.

Abstract: The salt passage of a reverse osmosis membrane is increased by: (a) contacting the membrane with ions to form a membrane-ion complex; (b) treating the membrane-ion complex with an aqueous solution of an alkali metal permanganate to form manganese dioxide crystals in the membrane; and (c) dissolving the manganese dioxide crystals. The process can be repeated any number of times to further open the membrane.

Abstract: Polyamide and polypyrrolone membranes for fluid separation having desirable permeabilities, solubilities, diffusivities,, high glass transition temperatures and large fractional free volumes. In particular, the membranes are the polyamide and polypyrrolone forms of hexafluoroisopropylidene-bisphthalic anhydride polymerized with 3,3',4,4' tetraaminodiphenylisopropylidene (6FDA-TADPIP) and polymerized with hexafluorotetraamine (6FDA-6FTA). Fluid separation membranes made from these polymers are described as well as a method of separating fluids using these membranes. Pure gas permeabilities and permeabilities with gas feed mixtures using the fluid separation membranes for feed pressures up to 900 psia indicate desirable permeability and no plasticization effects.

Abstract: In an apparatus and method for purifying water, an oxidation forcibly turns colloidal substances into fine particles of oxides, thus increasing the size of the particles. The effluent of oxidation process is treated by ion exchange process, and then treated by membrane process. Because of the increased size of the particles, they are easily removed in the subsequent ion exchange process. The membrane process is thereby prevented from clogging up, and then removes fine particles that cannot be removed by the ion exchange process. Colloidal substances are thus removed effectively from raw water.

Abstract: Water permeable reverse osmosis membranes are prepared by interfacially polymerizing on a microporous support an essentially monomeric polyamine reactant having at least two amine functional groups per reactant molecule, and an essentially monomeric amine-reactive polyfunctional single ring cycloaliphatic acyl halide having fewer than six carbon atoms per ring and having on the average at least about 2.2 acyl halide groups per reactant molecule. The polymerization is preferably carried out in the presence of a monomeric amine salt, which increases the flux rate of the resulting membrane. In addition, an aromatic polyfunctional acyl halide may be used in conjunction with the cycloaliphatic acyl halide in order to increase salt rejection rates. Preferred cycloaliphatic acyl halides are 1-cis, 2-trans, 3-cis, 4-trans-cyclopentane tetracarboxylic acid chloride, 1-cis, 2-trans, 3-cis, 4-trans-cyclobutane tetracarboxylic acid chloride and 1-cis, 2-trans, 4-cis-cyclopentane tricarboxylic acid chloride.

Abstract: A filter device and method are provided for treating parenteral nutrient fluids, particularly TNA systems containing lipids, glucose, and amino acids. The filter device comprises a housing and a microporous medium in the form of a synthetic polymeric microporous structure having a pore rating of less than 1.2 micrometers. A preferred microporous medium comprises, in series, a matrix of microfibers which has been radiation grafted to render the matrix wettable by parenteral nutrient fluids followed by a microporous membrane, also wettable by parenteral nutrient fluids, and having a finer pore rating than the microfibrous matrix.

Abstract: A method of treating an aqueous charge liquid, such as oilfield produced waters, containing boron and solubilized hydrocarbon compounds to reduce boron concentration, which comprises water softening to remove substantially all divalent cations, raising the pH of the liquid above about 9.5, and driving the liquid through a reverse osmosis membrane.

Abstract: Water permeable reverse osmosis membranes are prepared by interfacially polymerizing on a microporous support an essentially monomeric polyamine reactant having at least two amine functional groups per reactant molecule, and an essentially monomeric, at least trifunctional cyclic chloroformate amine-reactive reactant, wherein at least one of the functional groups is a chloroformyl group and the remaining functional groups of the amine-reactive reactant, if any, are acyl halides. The polymerization is preferably carried out in the presence of a monomeric amine salt, which increases the flux rate of the resulting membrane. In addition, an aromatic polyfunctional acyl halide and/or a polyfunctional cycloaliphatic acyl halide may be used in conjunction with the cyclic chloroformate in order to increase flux rates and possibly other desired properties. A preferred cyclic chloroformate is 5-chloroformyl isophthaloylchloride.

Abstract: A blood plasma-separating membrane formed of a porous membrane possessing a wetting time in the range of 3 to 500 seconds relative to water and a non-priming grade blood plasma separator using the same.

Abstract: A charge containing dewaxed oil/dewaxing solvent may be treated to effect separation of components by a thermally cross-linked hydrocarbon-derived elastomer membrane, typified by polybutadiene.

Abstract: Mixtures containing methanol and dimethyl carbonate or methanol and methyl t-butyl ether may be treated by pervaporation to recover product containing decreased quantity of methanol.

Abstract: Asymmetric semipermeable membranes which consist of aromatic polycondensates having recurring units of the formula(--O--Z--O--Y--).sub.n (I)in whichY is the divalent radical of an aromatic sulphone or of an aromatic ketone and--O--Z--O--is a divalent diphenolate radical which consists to the extent of 0.1-100 mol % of all the diphenolate radicals of those of the formula ##STR1## with the meaning given in the description, are suitable for haemodialysis, haemodiafiltration, haemofiltration, ultrafiltration, microfiltration and reverse osmosis.

Abstract: A thin-film seimpermeable composite membrane employs the reaction product of N-alkyl phenylenediamine or N,N'-dialkyl phenylenediamine and a poly acyl halide, such as trimesoyl chloride. Preferably the membrane is post-treated with an acid solution followed by an aqueous solution of polyvinyl alcohol and a buffer and/or base to improve its physical properties.

Abstract: The use of reverse osmosis as an alternative or substitute method for the purification of a crude diagnostic agent. X-ray contrast agent, magnetic resonance imaging agent, or radiopharmaceuticals are purified by passing through a cross-linked reverse osmosis membrane.

Abstract: Mixtures of salts of organic carboxylic acids and organic compounds of non-salt character, dissolved in a C.sub.1 -C.sub.4 alkanol, can be concentrated or separated with a semipermeable membrane made from a copolyamide or copolyimide-amide which contains(a) a first aromatic diamine radical and (b) a second aromatic diamine radical which carries--SO.sub.3 M groups, where M is H.sym., a monovalent to polyvalent metal cation or an ammonium cation. Provided the first diamine radical contains C.sub.1 -C.sub.4 alkyl groups in the o-positions to the amino groups, the copolymers are radiation-sensitive and can be used for producing protective layers or relief images, development being carried out in an aqueous alkaline medium.

Abstract: Operative fluids containing lower glycol are contacted with semi-permeable membranes under reverse osmosis conditions to permeate lower glycol to provide a reclaimed lower glycol product. Exemplary operative fluids include antifreeze solutions, heat transfer fluids, deicers, quenchants, hydraulic fluids, lubricants, solvents and absorbents.

Abstract: Concentration of aqueous solutions of isopropanol may be effected by a composite membrane including a dibromobutane cross-linked poly(4-vinyl pyridine) bonded to a porous layer of polyacrylonitrile on a polyester backing.

Abstract: Hydrocarbon solvents used or the dewaxing and/or deasphalting of oils can be recovered by the selective permeation of said solvents through an interfacially polymerized membrane under reverse osmosis conditions.

Abstract: The present invention describes a method for the synthesis of unsaturated aliphatic polyesters, their crosslinking by thermal treatment and the use of the corresponding crosslinked membranes to separate aromatics from saturates.

Abstract: A composite semipermeable membrane which has a high electrolytes rejection even when the concentration of the electrolytes in feed water is very low and even if the pH of feed water is not less than 8 is disclosed. The composite semipermeable membrane of the present invention comprises a microporous substrate and a cross-linked polyamide-based ultra-thin membrane laminated on the microporous substrate, the ultra-thin membrane having a covalently bonded quaternary nitrogen atom.

Abstract: The present invention describes a method for the synthesis of saturated aliphatic polyesters by reaction of saturated or aromatic diacid chlorides with oligomeric aliphatic polyester diols, a method to thermally crosslink membranes prepared from the above saturated aliphatic polyesters, and the use of the crosslinked membranes to separate aromatics from saturates.