Effects of Deactivation

Figure 2. Effect of deactivation on viscosity of a living solution in THF of poly(2-vinylpyridine) MgBz prepared from dibenzylmagnesium living polymer...

The analyst should also be alert to the fact that some drug residues become bound to the tissues of the animal and that this may have the effect of deactivating the toxic potential of the residue. However, determining the total concentration of the parent compound and/or its major metabolites generally ensures the greatest margin of safety. 

Beeckman et al [ref 14] also calculated the effect of deactivation resulting from dual site coke formation on the selectivity for the case of the following set of parallel reactions ... 

When the rate equations for coke formation are available, accounting for the effect of deactivation in the modeling of chemical reactors is relatively straightforward an equation for... 

Kinetic data for Fischer-Tropsch synthesis on unsupported iron catalysts have been obtained as part of an overall study of the deactivation of iron catalysts. Data for unpromoted and potassium-promoted catalysts reacted at 1 aim total pressure are reported. At the reaction conditions used in this study, kinetic parameters for the potassium-promoted catalyst cannot be obtained without effects of deactivation. Reaction o ers in the power-law expression for the unpromoted catalyst are 1.4 and 0.60 for Ph2 and Pco> respectively. The unpromoted catalyst exhibits a deactivation order of 1 when the generalized power-law expression is used. 

This paper summarizes results from the kinetic study at 1 atm. Even at the relatively mild reaction conditions deactivation was evident. Moreover, kinetic parameters for K-promoted iron could not be obtained without significant effects of deactivation. 

In this paper, we analyze these aspects in more detail combining data from flow reactor studies, infrared studies in a flow reactor cell and results obtained in a high-speed transient micrcu eactor coupled with a mass quadrupole detector (TAP - Temporal Analysis of Products - Reactor). Furthermore, we show and discuss how it is possible to limit and control these effects of deactivation by the addition of SO during Q-Cs alkane oxidation. 

X 10 s and a collision efficiency of 1.6 x 10 deduced for the second order self-quenching process. The authors claim to have discounted the effects of deactivation by traces of oxygen. 

Figure 12. Effect of deactivation on startup transients for benzene hydrogenation.

Effect of deactivation and acid dealumination on the adsorption properties. 

Deactivation of catalysts, particularly by coke deposition (the main means of reversible FCC catalyst deactivation) has been the subject ofintensive study over the past 50 years (2-4). Initially, the loss of activity was correlated with the time on stream, but it is now generally accepted that a more appropriate approach to understanding the effect of deactivation by coke is to relate deactivation to the deposited coke concentration (5). Furthermore, few studies on the effect of catalyst formulation on both the product distribution and coke formation have appeared in the open literature. 

The effect of deactivating acid sites at the external surface of the zeolite crystals (Sample A) was examined in two experiments. In one, propene feed was... 

It was expected that the effect of deactivation is related to the Increased acidity of the support, which can appear after the contact with H S, even though Karge and Rasko applying IR technique (ref.11) claim the absence of dissociative adsorption of H2S over the faujasites with Si/Al ratio higher than 2.5. The TPD... 

Effect of Deactivator Concentration on ATRA in the Presence of AIBN... 

The general effects of deactivation of catalysts for halogenated hydrocarbon oxidation have been evaluated less thoroughly in commercial practice than other stationary source control catalysts, because commercial systems for such reactions have only recently been introduced. Nevertheless, a number of catalysts have been investigated for this service in the laboratory, and deactivation of the catalysts in halogenated hydrocarbon oxidation service is commonly observed. 

A common characteristic of the catalytic oxidation of halogenated hydrocarbons is the effect of deactivation on reaction selectivity. It is well known that the catalytic process does not entail an instantaneous transformation of reactants to products, such as CO2 and water vapor. Rather, there... 

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