Abstract: The invention describes methods for the production of a high purity aluminum salt solution via electrodialysis, and ultimately, the conversion of the high purity aluminum salt to high purity aluminum oxide.

Abstract: Provided are electrodialysis systems comprising a plurality of electrodialysis devices, wherein each electrodialysis device of the plurality of electrodialysis devices has a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream. The product inlet stream for a first electrodialysis device comprises the brine outlet stream of a second electrodialysis device. Further, a first portion of a feed stream is the brine inlet stream for the first electrodialysis device and a second portion of the feed stream is the brine inlet stream for the second electrodialysis device or a third electrodialysis device.

Abstract: The present invention relates to a process comprising the reaction of a cyanide with a hydrogen cyanide-reactive compound, characterized in that the cyanide is a cyanide salt and the process is an electrochemical process involving the transporting of a reaction mixture to which cyanide salt has been added through an electrochemical cell, in which process the cyanide salt reacts with the hydrogen cyanide-reactive compound while at least partly under the influence of an electric current the cyanide salt is acidified and the salt cation content is reduced.

Abstract: A method for continuously manufacturing lithium transition metal phosphates of the formula LiMPO4, comprising the steps of providing an aqueous reaction mixture containing LION, H3PO4, and a transition metal sulphate, converting the reaction mixture into a lithium transition metal phosphate, separating the solid lithium transition metal phosphate from the soluble part of the reaction mixture, subjecting the soluble part (diluate) to an electrodialysis, and isolating the part of the electrodialysate that contains an aqueous LiOH solution.

Abstract: A process for producing a gas using an electrodialysis apparatus includes flowing at least two solutions and an electrode solution into the apparatus, pressurizing the apparatus at a stack pressure, applying a voltage to the apparatus's electrodialysis stack so a dissolved gas is generated in the second solution, flowing the second solution out of the apparatus, regenerating the gas out of the second solution, and collecting the gas. A process for generating a product, like a gas, liquid, or supercritical fluid, using an electrodialysis apparatus includes flowing at least two solutions and an electrode solution into the apparatus, adjusting the temperature and pressure so the product will be generated from the second solution, applying a voltage to the electrodialysis stack of the apparatus so that the product is generated in the second solution, flowing the second solution out of the apparatus, and regenerating the product from the second solution.

Abstract: Provided is a cleaning process of producing lactic acid. Firstly saccharification liquid is prepared through saccharated materials, then fermented with nutritive materials and lactic acid bacteria, and liquid alkali is used to adjust the pH. The fermentation broth is filtrated with porous membrane, and the lactic acid bacteria in the interception liquid are then reintroduced into the porous membrane for recycling. The permeate from porous membrane is subjected to nanofiltration to be decolored and purified. The concentrated solution from nanofiltration and the cleaning liquid from fermentation tank and its affiliated equipment are filtrated and sterilized by using ceramic membrane, and then are reintroduced into the fermentation unit for recycling. The permeate from nanofiltration is then subjected to bipolar electrodialysis system to prepare lactic acid, and the liquid alkali produced at the same time is reintroduced into the fermentation tank for recycling.

Abstract: A system and method for recovery of CO2 includes an aqueous capture device having a capture solution. The aqueous capture device is arranged to receive gas and to capture components from the gas including at least CO2. An electrodialysis unit in operative connection with the capture device performs an electrodialysis operation on the capture solution including at least the CO2, wherein a CO2 rich process stream and a regenerated capture solution are generated from the capture solution including at least the CO2. The CO2 rich process stream is a pressurized process stream at a pressure which maintains the CO2 substantially within the CO2 rich process stream, while in the electrodialysis unit. In another alternative, at least the pH of the capture stream is controlled.

Abstract: An electrolytic method is provided for purifying an aqueous stream, including at least one contaminant ion. In one embodiment, the eluent stream flows through a purifying flow channel, including ion exchange bed, an electric field is applied through the flowing eluent stream in the purifying flow channel, and the contaminant ion is removed from the eluent stream. In another embodiment, no electric field is applied and the ion exchange bed is periodically regenerated. Two beds may be used with one bed on line while the other bed is regenerated followed by a reversal of flow.

Abstract: A new method for improving the efficiency of electrodialysis (ED) cells and stacks, in particular those used in chemical synthesis. The process entails adding a buffer solution to the stack for subsequent depletion in the stack during electrolysis. The buffer solution is regenerated continuously after depletion. This buffer process serves to control the hydrogen ion or hydroxide ion concentration so as to protect the active sites of electrodialysis membranes. The process enables electrodialysis processing options for products that are sensitive to pH changes.

Abstract: The invention includes novel anion exchange membranes formed by in situ polymerization of at least one monomer, polymer or copolymer on a woven support membrane and their methods of formation. The woven support membrane is preferably a woven PVC membrane. The invention also includes novel cation exchange membranes with or without woven support membranes and their methods of formation. The invention encompasses a process for using the membranes in electrodialysis of ionic solutions and in particular industrial effluents or brackish water or seawater. The electrodialysis process need not include a step to remove excess ions prior to electrodialysis and produces less waste by-product and/or by-products which can be recycled.

Abstract: An electrolytic method is provided for purifying an aqueous stream, including at least one contaminant ion. In one embodiment, the eluent stream flows through a purifying flow channel, including ion exchange bed, an electric field is applied through the flowing eluent stream in the purifying flow channel, and the contaminant ion is removed from the eluent stream. In another embodiment, no electric field is applied and the ion exchange bed is periodically regenerated. Two beds may be used with one bed on line while the other bed is regenerated followed by a reversal of flow.

Abstract: The present invention provides means for recovering and reusing useful component ions in electrolytic phosphate chemical treatment bath without subjecting them to waste water treatment. In the present invention, a phosphate chemical treatment bath which contains phosphate ions and phosphoric acid, metal ions that form a phosphate crystal to provide a film, metal ions that are reduced from cations in the solution to form a film as metals, and ions that are involved in the reaction of the above-mentioned phosphoric acid and various metal ions to form a film, but which does not substantially contain ions that are not involved in film formation, is used as the phosphate chemical treatment bath.

Abstract: An ion-exchange membrane having excellent resistance against organic fouling by high molecular weight organic ions etc. and showing low electric resistance is provided. Said ion-exchange membrane is characterized by that a polyether compound containing polyalkylene glycol chain, such as polyethylene glycol, polypropylene glycol, their derivatives, etc., is fixed on the surface and/or inside of the membrane. As examples of the mode of the fixation there are mentioned fixation by entanglement of the molecules forming the membrane and the molecules of the polyether compound, physical fixation of both molecules by the anchor effect, and chemical fixation of both molecules by the formation of covalent bond or ionic bond. Said ion-exchange membrane can be preferably used in case of removing low molecular weight electrolytes from an aqueous solution containing low molecular weight electrolytes and high molecular weight organic ions etc. through electrodialysis.

Abstract: An electrodialysis cell is operated in the presence of organic compounds that binds or chelates with the multivalent metals to form a metal chelating buffer. Among other things, this binding or chelating reduces power consumption, produces a stable cell operation, and avoids a fouling of the membranes while significantly improving membrane life, reliability, and operating costs. When a chelating agent is added to a salt solution containing multivalent cations, the chelating agent strongly binds with the cations, forming large size complexes. An ion exchange membrane retains these complexes within the compartment of the electrodialysis cell containing the feed solution. The multivalent cations is greatly inhibited from being transported across the cation exchange membrane, thus reducing the fouling of the cation membranes. Concurrently, the precipitation of the metals transported to the base loop is substantially abated.

Abstract: A method for electrodialysis is conducted in a multi-compartment, preferably a four compartment, electrodialysis cell configuration wherein an inexpensive source of protons, preferably from a strong inorganic acid enables the conversion of multivalent metal salts into valuable acid products, such as 2-keto-L-gluconic acid, a vitamin C precursor, and useful by-products, like calcium chloride.

Abstract: An apparatus and process produces salts by an electrodialysis operation. The basic electrodialysis apparatus is a cell having a number of compartments separated by membranes. A DC source is connected to drive a current through a feed stream passing through the cell which splits the salt stream into an acid and a base. The incoming feed may be nanofiltered to remove divalent metal. The base loop may be in communication with an ion exchange column packed with a material that removes multivalent cations. Depending upon the material being processed and the desired end result either or both the nanofiltration and the ion exchanged column may be used in the apparatus.

Abstract: A method of treating an acid treatment solution which includes steps of adding sulfuric acid to an acid treatment solution which contains therein non-alkaline metal ions to produce sulfate, and recovering the regenerated acid treatment solution from the acid treatment solution to which the sulfuric acid has been added by separating the sulfate therefrom. Also, a device for realizing the method, and a method of fabricating a support for a planographic printing plate using the same.

Abstract: A first process involves the partial electrodialysis of a dialkali metal salt of an aromatic hydroxycarboxylic acid or a dicarboxylic acid to produce the approximate monoalkali metal salt and the alkali metal hydroxide. The monoalkali metal salt is then treated with an acid such as a bisulfate to recover the aromatic hydroxycarboxylic acid or dicarboxylic acid. The resulting inorganic salt such as sodium sulfate may then be electrolyzed to sodium bisulfate and NaOH. A second process involves the electrodialysis at elevated temperatures of a (di)alkali metal salt of p-hydroxybenzoic acid produce free p-hydroxybenzoic acid and the alkali metal hydroxide. These are efficient and economical methods for recovering the acid and alkali metal hydroxide values, as well as the parent organic compound, from these dialkali metal salts.

Abstract: An electrodialytic method and device for the simultaneous production of acids and bases of high purity and higher concentration operates by splitting corresponding salts in aqueous solution using an electrolysis cell. The electrolysis cell includes a cathode chamber in which an alkali is formed, a salt chamber for supplying a salt to be split, an acid chamber in which the acid is formed, and an anode chamber through which a mineral acid flows as a proton carrier. The anode is a hydrogen-consuming electrode. The method and device are preferably used in the production of hydrochloric acid and sodium hydroxide solution.

Abstract: This invention relates to methods of controlling the oxidation of hydrocarbons to respective dibasic acids, such as adipic acid for example, by removing the catalyst from the reaction mixture, outside the reaction zone, after the oxidation has taken place at least partially. The catalyst is precipitated substantially in its totality by using a base, preferably sodium hydroxide, to form the catalyst hydroxide, such as cobalt hydroxide for example. Preferably, the precipitated catalyst is recycled to the reaction zone with or without further treatment. The method may also include steps for treatment of the reaction mixture by hydrolysis and/or electrodialysis.

Abstract: A method for fermentation of lactic acid from a sugar-containing fermentation liquid in a fermentor by means of lactic acid-forming bacteria, in which whey protein is present or is added as a nutrient substrate for the lactic acid-forming bacteria, wherein at least one protease is added to the fermentor during the fermentation, so that hydrolysis of protein to amino acids takes place simultaneously with the fermentation of sugar into organic acid, and wherein lactic acid resulting from the fermentation is isolated from the fermentation liquid. Ammonia is preferably added to result in the formation of ammonium lactate, and lactic acid is preferably isolated by a process comprising ultra filtration, ion exchange, conventional electrodialysis and electrodialysis with bipolar membranes.

Abstract: An apparatus and process produces salts by an electrodialysis operation. The basic electrodialysis apparatus is a cell having a number of compartments separated by membranes. A DC source is connected to drive a current through a feed stream passing through the cell which splits the salt stream into an acid and a base. The incoming feed may be nanofiltered to remove divalent metal. The base loop may be in communication with an ion exchange column packed with a material that removes multivalent cations. Depending upon the material being processed and the desired end result either or both the nanofiltration and the ion exchanged column may be used in the apparatus.

Abstract: An apparatus and process produces salts by an electrodialysis operation. The basic electrodialysis apparatus is a cell having a number of compartments separated by membranes. A DC source is connected to drive a current through a feed stream passing through the cell which splits the salt stream into an acid and a base. The incoming feed may be nanofiltered to remove divalent metal. The base loop may be in communication with an ion exchange column packed with a material that removes multivalent cations. Depending upon the material being processed and the desired end result either or both the nanofiltration and the ion exchanged column may be used in the apparatus.

Abstract: An apparatus and process produces salts by an electrodialysis operation. The basic electrodialysis apparatus is a cell having a number of compartments separated by ion exchange membranes. A DC source is connected to drive a current through a feed stream passing through the cell which splits the salt stream into an acid and a base. The incoming feed may be nanofiltered to remove divalent metal. The base loop may be in communication with an ion exchange column packed with a material that removes multivalent cations. Monovalent selctive cation membranes may be used to effect preferential treatment of the monovalent cations to the base loop. Depending upon the material being processed and the desired end result either or both the nanofiltration and the ion exchanged column may be used in the apparatus.

Abstract: The present invention relates to a process for isolating, by membrane electrodialysis, a catalyst from a solution containing it. More precisely, it relates to the isolation of a catalyst used in a homogeneous phase molecular oxidation reaction. The invention consists of a process for isolating a homogeneous catalyst dissolved in a mixture also containing at least one aliphatic diacid, characterized in that the catalyst contains cobalt and the isolation is performed by membrane electrodialysis.

Abstract: The invention uses a stack of three compartment electrodialysis cells in a process for the production amino acid hydrochloride and an alkali. The electrodialysis cell contains bipolar, cation and anion membranes which are arranged to form acid, base and salt compartments. The process begins with supplying a salt solution to the salt compartment, water to the base compartment, and a liquid comprising an amino acid to the acid compartment. Preferably, the feed salt is sodium chloride or potassium chloride or lithium chloride. A direct current driving force is applied across the cell to convert the salt solution to an alkali in the base compartments and an amino acid hydrochloride in the acid compartment. The acid and alkali solutions and a depleted salt solution are withdrawn from their respective compartments. A chelating agent may be added to the salt solution before it is fed into the electrodialysis cell.

Abstract: An on-site process and apparatus for producing hydrogen peroxide at a high efficiency substantially from brine and oxygen-containing gas alone as raw materials while removing alkaline earth metals. Sea water concentrated by an electrodialytic apparatus 2 or the like as a raw material is supplied to an impurity removing apparatus 10 where caustic soda produced in an acid-alkali producing apparatus 11 at a subsequent stage and/or carbon dioxide gas is added to remove alkaline earth metals contained in sea water in the form of a hydroxide or carbonate precipitate. Separately, the acid-alkali producing apparatus 11 performs a salt separating operation to produce caustic soda which is then supplied to a hydrogen peroxide generator 28 to produce an alkaline aqueous solution of hydrogen peroxide.

Abstract: The invention relates to an electrochemical process for the production of sodium hydroxide and sulfuric acid from aqueous sodium sulfate solutions, said process comprising the feeding of an aqueous sodium sulfate solution into a salt splitter device comprising at least three compartments including a middle feed compartment which is between an anode compartment and a cathode compartment, wherein the feed compartment is separated from the anode compartment by a chemically-functionalized anion exchange membrane, and wherein the feed compartment is separated from the cathode compartment by a chemically-functionalized cation exchange membrane. Specifically, the chemically-functionalized anion exchange membrane of the present invention is a perfluorohydrocarbon polymer material to which has been grafted a plurality of benzo-crown ether groups which have been complexed with a metal ion selected from sodium, potassium and lithium.

Abstract: A method for treating waste nitrocellulose, the method comprising the steps f treating nitrocellulose with acid in a hydrolysis process to break the nitrocellulose down to glucose, recovering a majority of the acid by electrodialysis, neutralizing a remainder of the acid, and fermenting the glucose to convert the glucose to a useful product. The invention further comprises a system for performing the above method.

Abstract: In an electrolyzer provided according to this invention, the polarity of electrodes is periodically inverted at very short intervals. This has the effect of allowing gases to be generated uniformly all over the surface of each electrode in the form of extremely small bubbles instead of being formed in specific positions in the form of large bubbles as is the case with a conventional electrolyzer in which a direct current is allowed to flow without changing the flow direction. Thus the surfaces of electrodes are prevented from being covered with bubbles, and the flow of liquids along the surfaces of electrodes is not disturbed by the bubbles any more.

Abstract: In a process for an electrochemical treatment of cellulose waste lye, mass transport takes place through a diaphragm or membrane between a cathode chamber and an anode chamber, and optionally through a middle chamber. Cationogenic components are removed from cellulose waste lye containing lignin sulfonates and being located in at least one of the chambers. Lignin sulfonic acids are produced from the waste lye. In an installation for an electrochemical treatment of cellulose waste lye, at least one diaphragm divides at least one reaction vessel into at least one cathode chamber and at least one anode chamber. At least one cathode electrode is disposed in the at least one cathode chamber, and at least one anode electrode is disposed in the at least one anode chamber. The at least one cathode electrode is formed of iron or aluminum and the at least one anode electrode is formed of special steel, in particular V4A steel.

Abstract: Methods for preparing hypophosphorous acid are disclosed comprising contacting an insoluble anode with an aqueous solution of hypophosphite anions and applying a current through the insoluble anode to a cathode in electrical contact with the aqueous solution to generate H+ ions in the aqueous solution thereby forming a hypophosphorous acid solution.

Abstract: A process for the recovery of alkali metal hydroxide and acid from the alkali metal salts of monovalent anions which are mixed with the alkali metal salts of multivalent anions employs a water-splitting system composed of bipolar membranes in conjunction with ion-selective membranes; a two-compartment cell employs monovalent anion-selective membranes to define salt/base and acid compartments with the bipolar membranes, and a three-compartment cell employs, monovalent anion-selective and cation-selective membranes to define with the bipolar membranes, acid, salt and base compartments; the process has particular applicability to the conversion of the sodium/potassium chloride portion of the Electrostatic Precipitator (ESP) Catch of the recovery boiler of coastal and/or closed-cycle kraft pulp mills, a mixture of mostly sodium/potassium sulphate and chloride, into sodium/potassium hydroxide and hydrochloric acid; the remaining sodium/potassium sulphate solution, depleted in chloride, can thus be used as sodium/s

Abstract: Apparatus for the corona discharge treatment of a travelling web such as a plastics or cellulose film comprises a pair of spaced conductors with an associated alternating voltage power supply set at such a distance apart that the possibility of spark or arc discharge is avoided, at least one conductor having mounted thereto an electrode member extending towards the other conductor to define a gap across which a corona discharge can be formed. The electrode member consists of a dielectric material having a dielectric constant of at least 8, preferably at least 80, and may consist of a plate with an edge directed towards the other conductor. Preferably the plate is formed of one or more ceramic tiles based upon a titanium and/or zirconium compound. In another form the electrode member consists of a row of rods or two or more rows of spaced rods in staggered relationship.