Ion exchange resin, use

McCabe-Thiele diagrams for nonlinear and more practical systems with pertinent inequaUty constraints are illustrated in Figures 11 and 12. The convex isotherms are generally observed for 2eohtic adsorbents, particularly in hydrocarbon separation systems, whereas the concave isotherms are observed for ion-exchange resins used in sugar separations. 

Removal of brine contaminants accounts for a significant portion of overall chlor—alkali production cost, especially for the membrane process. Moreover, part or all of the depleted brine from mercury and membrane cells must first be dechlorinated to recover the dissolved chlorine and to prevent corrosion during further processing. In a typical membrane plant, HCl is added to Hberate chlorine, then a vacuum is appHed to recover it. A reducing agent such as sodium sulfite is added to remove the final traces because chlorine would adversely react with the ion-exchange resins used later in the process. Dechlorinated brine is then resaturated with soHd salt for further use. 

A volume measure of the permitted flow rate of water through ion exchange resins and sometimes other media, such as sand. Typically, ion-exchange resins used for water softening will tolerate 8 to 40 BV/hr. 

This wastewater stream contains lead (Pb) salts and chlorinated hydrocarbons generated from corrosion of the anodes as well as asbestos particles generated as a result of degradation of the diaphragm with use. Wastewater is also generated from the scrubber where the chlorine is wet scrubbed and from the ion exchange resin used to purify the brine solution. These wash water often contains dilute hydrochloric acid with small amounts of dissolved calcium magnesium and aluminum chloride. Like in other cells, the scrubber water also contributes to the wastewater stream. 

NRS [New Regeneration System] A process for regenerating the ion-exchange resin used for removing calcium from sugar solution. If sodium chloride were used, the waste calcium chloride solution would have to be disposed of if sodium hydroxide were used, calcium hydroxide would be precipitated in the resin. The NRS process uses sodium hydroxide in the presence of sucrose, which retains the calcium in solution as calcium saccharate. Developed by the IMACTI Division of Duolite International, The Netherlands. 

Quentin A process for regenerating the ion exchange resin used in sugar refining, using magnesium chloride solution. 

The ion-exchange resins used as etherification catalysts are strongly acidic cation-exchange resins. These materials consist typically of polystyrene chains that have been linked with divinylbenzene (DVB), the amount of which determines the degree of crosslinking and regulates the rigidity of the structure schematically presented in Fig. 10.3 [24],... 

CMP-Neu5Ac can be completely purified on a large scale on Dowex-1 X4 ion-exchange resin, using a gradient of 0.01-2 M triethyl-... 

Amberlite. Trade name for resorcinol type resins used for wood adhesives and manufd by the Rohm Haas Co, Phila 5,Pa. Also a trade-mark name for insoluble crossed-linked polyelectrolytes (ion-exchange resins). Used for water conditioning and other purposes... 

Ion exchange can be an effective method for the controlled release of ionizable drugs that are coupled with the oppositely charged ionic groups on a polymer matrix, as in ion-exchange resins used in gastrointestinal (Gl) applications. The drug release from such a system depends on the ionic environment, that is, pH and electrolyte concentration within the Gl tract, as well as the properties of the resin (5). 

Resolution of the Council of Europe AP (89) 2 relating to ion-exchange resins used in the processing of foodstuffs ... 

The Dowex AG 1-xlO ion exchange resin used in our test has the capacity to remove both acidic aggregates and free [ I]iodide salts. This resin has been used to monitor the iodination reaction " and to remove free iodide formed during storage of the purified labeled material. ... 

Ion-exchange chromatography is widely used to separate and analyze mixtures of amino acids. The most common ion-exchange resin used for this purpose is a sulfonic acid cation exchanger of the Dowex-50 (polystyrene) type. The structure of the resin is ... 

U 26597A Colestid ) is an insoluble high molecular-weight ion-exchange resin, used as an antihyperlipidaemic. colestipol hydrochloride colestipol, colestyramine cholestyramine. 

HCR [Dow], TM applied to ion-exchange resin used in water-treating and chemical process applications strong acid cation-exchange resin, 8% divinylbenzene cross-linked. 

SNF constitutes about half of the HLW in the United States. The other half comes from the construction and existence of nuclear weapons. All HLW is a federal responsibility. About 90% of the radioactivity in nuclear waste is from HLW. The largest volume of nuclear waste is low-level waste (LLW) and that is mostly the responsibihty of the state (or group of states) in which it is generated. LLW is rather awkwardly defined, being everything that is neither HLW nor defense waste and consists of wastes from hospitals pharmaceutical labs research labs and the moon suits, tools, and the like from nuclear power plants. In the eastern United States, most of the LLW is in the form of the plastic beads that make up the ion-exchange resins used in nuclear power plants to clean various loops of water used in power production. 

A large number of papers have been published on the process modeling and optimization of the etherification process. More details could be found in a handbook. The most important aspect of process improvement is catalyst improvement because the Amberlyst ion-exchange resin used in the MTBE synthesis has an upper thermal stability limit of less than 100°C and there is a need to develop other acidic catalysts with higher thermal stability. Some of the recent papers have described the use of zeolites. 

Since in this reaction each mole of styrene gives one mobile charge, the number of moles styrene defines the number of mobile charges (each mole produces one mobile charge), which is also equal to the number of moles ion-exchanger resin. Using 100 g styrene as a point of reference, the number of moles styrene is... 

The ion-exchange resins used in modern chromatography are smaller in size but have a lower capacity than older resins. Columns packed with these newer resins have more theoretical plates than older columns. For this reason, successful separations can now be obtained even when there are only small differences in retention times of the sample ions. 

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