Abstract:
An improved apparatus and operating method related thereto for deionizing water to produce substantially pure water using electric field and ion exchange materials are disclosed, including embodiments incorporating one or more of the novel features of brine and electrode streams flowing in a direction counter-current to the stream being deionized, a filling of the brine stream with stratified ion exchange materials, a stream mixing feature for mixing the stream being deionized, a gas removal feature for removal of gases, a spiral-wound embodiment of an electrodialysis device according to the invention, and a method for determining the preferred operating current for electrodialysis systems according to this invention.
Abstract:
The invention provides ion exchange and electrochemical methods and devices employing anion exchange polymers produced by substantially simultaneous quaternization and polymerization reactions. Anion selective polymers are produced in accordance with the invention by combining, an ethylenic tertiary amine monomer, an alkylating agent having a boiling point temperature of at least about 100° C., and a cross-linking agent in the presence of a polymerizing agent for a time and at a temperature sufficient to form the polymer. The alkylating agent and the cross-linking agent may be the same compound, a cross-linking alkylating agent. The polymers may be produced in the presence of solvents and/or in the presence of diluting monomers which are incorporated into the polymers.
Abstract:
This invention is directed to producing highly concentrated solutions of methylenebisacrylamide and thereafter blending with ionogeneous acrylic monomers to produce low porosity, highly crosslinked, water insoluble polymers for use as anion selective resins and membranes.
Abstract:
A fluid from a fermentation process or the like is passed or circulated through chambers of a bipolar membrane electrodialysis unit to separate an ionizable organic acid stream and at least one co-ion or residual stream. The organic acid stream is preferably concentrated (e.g., by recirculation, dewatering or both), and a product is recovered from the concentrated stream, for example by crystallization, and other outputs from the electrodialysis unit may be integrated with overall treatment and applied elsewhere in the treatment system. Depleted feed may be returned upstream to enhance yield, condition the medium or form a by-product. Treatment systems of the invention may replace a cation exchange bed and/or various filter arrangements, and recirculation of the feed and product flows through the unit enhance recovery, separation and quality of the target species. An ED chamber may include a filling of ion exchange beads to maintain a desired operating efficiency as the feed is depleted, and the straight-through operation effectively operates as pre-filtration stage to provide downstream product-bearing flows with processing characteristics for enhanced treatment, recovery and product quality. When operated to treat a downstream waste, systems allow additional recovery of value in the form of product, unexpended nutrients, co-factors and/or other components present in the waste.
Abstract:
Electrodialysis ("ED") stacks are disclosed having components selected from the group:a) cation exchange ("CX") membranes and/or CX granules having in at least a surface a predominant amount of sulfonate exchange groups and a minor amount of weakly ionized exchange groups;b) anion exchange ("AX") membranes and/or AX granules having in at least a surface substantially only quaternary ammonium and/or phosphonium exchange groups which upon decomposition leave almost no amine or phosphine groups bound to the membranes or granules;c) AX and/or CX granules which are selective to monovalent ions at currents which are fractions of the limiting current of such granules;d) AX and/or CX membranes and granules, such membranes and granules selective to monovalent ions at currents which are fractions of the limiting current of such membranes and granules;e) ion exchange ("IX") granules in which the concentration of IX groups in the inner regions is a fraction (including zero) of the concentration in the outer regions;f) AX membranes and/or granules having in at least a surface AX groups having the formula ##STR1## where the R's represent substituents other than hydroxyethyl having at least two carbon atoms, at least one of the R's represents the polymeric structure of such membranes or granules, or a connection thereto, where two or more R's may represent ring structures and A represents nitrogen or phosphorus.Also disclosed are processes for softening, de-nitrating, de-silicizing or demineralizing water or for removing ash from milk products.
Abstract:
This invention pertains to processes for manufacturing in an environmentally friendly way, continuous, supported ion exchange membranes from (I) liquids containing vinyl and related monomeric electrolytes and high boiling solvents therefor, said solvents also being swelling agents for said membranes; and (II) an indefinitely long, foraminous substrate and to the products of such processes.
Abstract:
A linear exchange element with functionalized polymer on a core of rope, twine or yarn has well defined physical structure and may function as a spacer or be formed into free-standing exchange elements. A screen is fabricated from such strands or strips, with a pattern of mixed, sequential or other exchange types for enhanced operation in a capture device or in an electrodialysis device. Strands possess tensile strength, enabling deionization devices of new architecture, such as fiber-wound cartridges and other packing arrangements. Bodies made of the strands may operate as walls to perform the function of an exchange membrane or bed, or may operate as spacers positioned between membranes to enhance ion capture and transport, and their properties simplify handling and regeneration. Electroseparation devices advantageously employ the open spacers to better treat food, fermentation product or other streams where high conductivity, suspended solids and fouling would otherwise present problems. “Woven” mats may be arranged so that strands of one type in a first layer possess at least some points of contact with strands of opposite type in an adjacent layer, and different strand diameter and mesh pitch or dimension may be employed for treating fluids of different viscosity or concentration to optimize treatment throughput and removal rate, or to minimize fouling or flow obstruction and otherwise extend the range of treatment parameters.
Abstract:
EDI apparatus for demineralizing a liquid flow is assembled in a housing having a cylindrical shape, and includes two metal electrodes, and one or more leafs, each leaf comprising a pair of selectively ion-permeable membranes arranged parallel to each other and spaced apart by spacing elements that allow liquid to flow in the interstitial space between membranes, thus forming an arrangement of dilute and concentrate cells in a desired flow configuration. Spacing elements between membranes, as well as between leaves, can be formed of inert polymer material, ion exchange beads, ion exchange fibers, a combination of two or more these elements, or a porous media incorporating one or more of such elements as an intrinsic part. An inner or central electrode and an outer or perimeter electrode establish a generally uniform and radially-oriented electrical or ionic current between the inner and the outer electrodes, across the helical flow spaces defined by the membrane/spacer windings. One or both electrodes may include a pocket, and the adjacent flow cells lie parallel to the electrode and free of shadowing and field inhomogeneity around a full circumference of the electrode. Flow paths within the helical cells are defined by barrier seals, which may form a path-lengthening maze, while unfilled cell regions may disperse or collect flow within a cell and define pressure gradients promote directional flows. Impermeable barriers between membranes further prevent the feed and concentrate flows from mixing. In various embodiments, seals along or between portions of the flow path may define a multi-stage device, may define separate feed and/or concentrate flows for different stages, and/or may direct the feed and concentrate flows along preferred directions which may be co-current, counter-current or cross-current with respect to each other within the apparatus.
Abstract:
A water or alcohol-water soluble divinyl monomer having anion exchange group(s) and a free exchangable anion is disclosed. These bifunctional divinyl monomers are capable of forming ion exchange materials (membranes and ion exchange resin beads) upon polymerization with added vinyl catalysts which convert them into insoluble and infusible polymers. They are also capable of being co-polymerized with other ion exchange (ion containing) monomers to give unique anion exchange resins or membranes.
Abstract:
In contrast to prior art conventional anion selective membranes, the membranes of this invention have a low transport number for hydrogen ions (e.g. t.sub.H.spsb.+ .ltoreq.0.3) and a high transport number for low ionic weight anions (e.g. t.sub.A.spsb.- .gtoreq.0.7) in acid solutions (e.g. 0.5 to 1.0 gram-equivalents H.sup.+ per liter). As compared to such prior art membranes, those of this invention have a critically lower ratio of water content to anion exchange capacity.