Abstract: An electrodialysis method using a bipolar membrane (BP) for regenerating acids, wherein a series of base (B), acid (A) and salt (S) compartments are provided between a positive electrode (anode) and a negative electrode (cathode), said compartments being defined by a series of membranes: cationic, bipolar, anionic, cationic, bipolar and so forth, and a solution being circulated through each compartment. An additional anionic membrane (10) is applied to the anionic side (11) of the bipolar membrane (BP) with no discernible gap therebetween so that contamination of the acid compartment by cations is reduced.

Abstract: A gasket for an electrodialysis cell assembly has a series flow path comprising a plurality of flow path sections joined by restrictor sections. Each of the flow path sections has a relatively wide width. The restrictor has less than the wide width so that a fluid flowing in the series flow path must increase its velocity as it flows through the restrictor. The result is that the fluid exiting the restrictor cause turbulence and agitation in the flow path sections. Manifold holes are located at opposite ends of the series flow path. A rigid port is positioned between each of the manifold holes and the ends of the series flow path. The successive cells of the assembly are defined by a pair of bipolar membranes with cation and/or anion exchange membranes between them. One of the gaskets is located between each two of the membranes.

Abstract: Describes a method of electreochemically converting amine hydrohalide, e.g., amine hydrochloride, into free amine, e.g., free ethyleneamine. An electrolytic cell is provided having (1) a catholyte compartment containing a cathode assembly comprising a cathode and a bipolar ion exchange membrane, (2) an anode compartment containing an anode assembly comprising either (a) a hydrogen consuming gas diffusion anode and a current collecting electrode or (b) a hydrogen consuming gas diffusion anode which is fixedly held between a hydraulic barrier and a current collecting electrode, and (3) at least one pair of intermediate compartments separating the catholyte and anode compartments and separated from each other by an anion exchange membrane.

Abstract: Process for the manufacture of a bipolar membrane, according to which an anionic membrane is joined side by side to a cationic membrane, the membranes having been subjected beforehand to a conditioning pretreatment, the conditioning pretreatment of the anionic membrane comprising bringing the latter into contact with a compound of a polyvalent metal and with an aqueous alkali metal hydroxide solution and the conditioning pretreatment of the cationic membrane essentially comprising bringing the said cationic membrane into contact with water which is essentially free from polyvalent metal and from alkali metal. Use of the bipolar membrane thus obtained for the manufacture of aqueous sodium hydroxide solutions by electrodialysis.

Abstract: A electrochemical cell for removing ions from a solution stream comprises a housing having first and second electrodes. At least one water-splitting ion exchange membrane is positioned between the electrodes, the water-splitting membrane comprising (i) a cation exchange surface facing the first electrode, and (ii) an anion exchange surface facing the second electrode. A solution stream pathway is defined by the water-splitting membrane. The solution stream pathway comprises (i) an inlet for influent solution stream, (ii) at least one channel that allows influent solution stream to flow past at least one surface of the water-splitting membrane to form one or more treated solution streams, and (iii) a single outlet that combines the treated solution streams to form a single effluent solution.

Abstract: The invention relates to a process for the separation of lactulose from a mixture of lactulose and lactose in the presence of a weak acid capable of reversibly forming a complex with lactulose, by using an electrodialysis equipment including an anode and a cathode compartment separated by a plurality of parallel compartments comprising alternating diluate and concentrate compartments, wherein adjacent compartments are separated from each other by permselective membranes; which process is characterized by:(a) continuously passing an alkaline aqueous solution of lactulose, lactose and said complex forming weak acid through the diluate compartments, each diluate compartment being bound by a bipolar membrane at its lateral side facing the cathode and at its opposite lateral side by an anion exchange membrane, separating said compartment from its adjacent concentrate compartment;(b) continuously passing a carrier fluid through the concentrate compartments, each concentrate compartment being bound at its lateral si

Abstract: A method for recovering salt from a process stream containing organic contaminants is provided, comprising directing the waste stream to a desalting electrodialysis unit so as to create a concentrated and purified salt permeate and an organic contaminants containing stream, and contacting said concentrated salt permeate to a water-splitting electrodialysis unit so as to convert the salt to its corresponding base and acid.