Exchange heterogeneous

Key words inorganic ion exchanger, titaniiun tungstate, metal complex catalysis, anchored ion exchangers, heterogenized homogeneous catalysis. 

To make a fuel-processing reactor out of a microstructured plate heat exchanger, heterogeneous catalysts need to be introduced into the microchannels, usually by wash-coating, similar to the procedure established for automotive exhaust clean-up. 

Esterification. Extensive commercial use is made of primary amyl acetate, a mixture of 1-pentyl acetate [28-63-7] and 2-metliylbutyl acetate [53496-15-4]. Esterifications with acetic acid are generally conducted in the Hquid phase in the presence of a strong acid catalyst such as sulfuric acid (34). Increased reaction rates are reported when esterifications are carried out in the presence of heteropoly acids supported on macroreticular cation-exchange resins (35) and 2eohte (36) catalysts in a heterogeneous process. Judging from the many patents issued in recent years, there appears to be considerable effort underway to find an appropriate soHd catalyst for a reactive distillation esterification process to avoid the product removal difficulties of the conventional process. 

Diffusion in porous solids is usually the most important factor con-troUing mass transfer in adsorption, ion exchange, drying, heterogeneous catalysis, leaching, and many other applications. Some of the... 

Heterogeneity Adsorbents and ion exchangers can be physically and chemically heterogeneous. Although exceptions exist, solutes generally compete for the same sites. Models for adsorbent heterogeneity have been developed for both discrete and continuous distributions of energies [Ross and Olivier, On Physical Adsorption, Interscience, New York, 1964 Jaroniec and Madey, Rudzinsld and Everett, gen. refs.]. 

There was studied dependence of sorption rate values of microamounts high listed elements from time of their contact with sorbents, pH media and means of equilibrium concentration. It is shown that owing to exchange of sorbents surface characteristics, its hydrating rate value and heterogeneity of sorbate and hydrolyzed forms of metals investigated interaction with surface can simultaneously proceed on several mechanisms. The contributions of various factors into adsorption of elements-analogues are depended from sorption conditions and nature of sorbent surface. 

Where Water Hammer Occurs. Water hammer can occur in any water supply line, hot or cold. Its effects can be even more pronounced in heterogeneous or biphase systems. Biphase systems carry water in two states, as a liquid and as a gas. Such a condition exists in a steam system where condensate coexists with live or flash steam in heat exchangers, tracer lines, steam mains, condensate return lines and, in some cases, pump discharge lines. 

Ethyl-ter-butyl ether (ETBE) is also produced by the reaction of ethanol and isobutylene under similar conditions with a heterogeneous acidic ion-exchange resin catalyst (similar to that with MTBE) ... 

Heterogeneity. Natural aequorin is not a homogeneous protein it is a mixture of many isoforms having isoelectric points ranging from 4.2 to 4.9 (Blinks and Harrer, 1975). The isoform composition may vary to some extent by the purification method employed, due to uneven loss of isoforms during purification. Consequently, the properties of each preparation of aequorin may also vary. By anion-exchange... 

Furthermore, for calculating the effective coefficient of quasi-diffusion in a composite (D) with the corresponding limitation of the entire process of heterogeneous mass-exchange, equations reported in Section 5.1 may be used. The high kinetic permeability of cellosorbents for large organic ions are listed in Table 16. 

In order to consider chromatographic processes in a more universal manner as processes in which film control of heterogeneous mass-exchange is also possible, dimensionless criteria for the conditions of formation of sharp zone boundaries may be represented by the parameter A [124,125]. The evaluation of this parameter is carried out on the basis of dynamic (chromatographic) and kinetic experiments ... 

The chemical properties of oxide surfaces have been studied by several methods, including oxygen exchange. This method has been used to investigate the mechanisms of heterogeneous reactions for which oxides are active catalysts [36]. The dimerization step does not necessarily precede desorption and Malinin and Tolmachev [634], in one of the few reviews of decomposition kinetics of solid metal oxides, use this criterion to distinguish two alternative reaction mechanisms, examples being... 

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