Exchange resins molecular sieve

Zeolites are open-framework aluminosilicates, widely used in industrial applications as ion exchange resins, molecular sieves, sorbents, catalysts, and catalyst supports [2,3]. The first natural zeolite, stilbite, was discovered over 200 years... 

The full paper has been published on the preparation of esters by ester exchange, using molecular sieves as selective alcohol traps. A method of esterification using a catalytic dehydrator has been reported, where the combination of an acid ion-exchangc resin and a drying agent is employed. 

In contrast to trace impurity removal, the use of adsorption for bulk separation in the liquid phase on a commercial scale is a relatively recent development. The first commercial operation occurred in 1964 with the advent of the UOP Molex process for recovery of high purity / -paraffins (6—8). Since that time, bulk adsorptive separation of liquids has been used to solve a broad range of problems, including individual isomer separations and class separations. The commercial availability of synthetic molecular sieves and ion-exchange resins and the development of novel process concepts have been the two significant factors in the success of these processes. This article is devoted mainly to the theory and operation of these Hquid-phase bulk adsorptive separation processes. 

ZeoHte-based materials are extremely versatile uses include detergent manufacture, ion-exchange resins (ie, water softeners), catalytic appHcations in the petroleum industry, separation processes (ie, molecular sieves), and as an adsorbent for water, carbon dioxide, mercaptans, and hydrogen sulfide. 

Formamide (specific conductance 2 x 10 ohnr cnr ) of low water content was dried by passage through a column of 3A molecular sieves, then deionized by treatment with a mixed-bed ion-exchange resin loaded with H" " and HCONH" ions (using sodium formamide in formamide)[Notley and Spiro J Chem Soc (B) 362 1966. ... 

Some zeolites have the ability to exchange sodium for calcium and thereby function as water softeners by removing Ca2+. After the zeolite has become saturated with Ca2+, it can be renewed by washing it in a concentrated NaCl solution to restore the Na+ ions. Zeolites are also used to prepare ion exchange resins, as molecular sieves and as catalysts. 

Macroporous cation exchangers, 14 387 Macroporous gels, 13 738 Macroporous molecular sieves, 16 849 Macroporous particles, apparent effective diffusivity and, 15 730 Macroporous resins, 14 393, 397 Macroreticular sulfonated styrene-... 

UOP molecular sieves (UOP) has developed the lonsiv family of ion exchange resins for the extraction of radionuclides from wastewater. lonsiv TIE-96 is composed of a titanium-coated zeolite (Ti-zeolite) and is used to separate plutonium, strontium, and cesium from alkaline supernatant and sludge wash solutions. The technology was developed by Pacific Northwest Laboratory (PNL) for use at the West Valley, New York, nuclear waste facility. The technology is commercially available. 

Asymmetric hydrogenations have been reported with palladium on silk 123>, palladium on modified cellulose 124> and on modified ion exchange resins 125 >. Also with Raney Nickel modified with amino adds 126> and peptides, 27>. Platinum-carbon catalysts exhibiting shape selectivity have been made by coating them with a thermosetting resin, which is carbonized. In such a way an organic molecular sieve skin is formed over the original catalyst 128>. 

The attachment of particular solute molecules to the surface of the particulate sorption packing material can be achieved by a number of different methods, which are outside the scope of this paper. There are a large number of different sorption materials and complex physical and chemical interactions which must be considered. The most common sorption materials are activated carbon, silica gel, activated alumina, molecular sieves, and ion exchange resins. This chapter deals with the industrial aspects of handling these materials and operating process-scale equipment, but does not look at the choice of sorption material for a particular process. 

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