INDEX reaction orders

Table 6.10 Overall reaction order, m, in the dark zone determined from the pressure exponent of burning rate, n, and the dark zone index, d.

Fig. 43. (a) Effect of order of reaction on plots of reaction rate against temperature for constant heating rate, frequency factor and activation energy. EjR = 20,000, lnA = 16.0. From ref. 350. (b) Method of measuring reaction order from the shape index of dta peak. Shape index S = alb. 

Here, u is the linear speed of combustion reactions a is a constant which is determined by the reactions in condensed phase and the thermal conductivity is a coefficient which is determined by reactions in gas phase v is an index which is determined by the reaction order of dominant reactions in gas phase. 

In a homogeneous reaction, the reaction order is associated with molecular interaction mechanism and has its specific mean of theory. For the process of catalysts deactivation, the index of activity loss is a convenient and simple tool that can be used to integrate and simplify the mathematical treatment and design. However,... 

The m value is similar to the reaction order, which is called as the reaction index. Table 5.4 lists the parameters in Eq. (5.52), which corresponds to a variety of dynamic models. 

The index 1 refers to the conditions at the end of the reaction. This equation is also applicable to plug flow reactors, then the index 1 refers to exit conditions. With eq. (3.58) the selectivity can be calculated as a function of the degree of conversion (without considering the time coordinate), for any value of the reaction orders p and jc. We see at once that when p > jc, the selectivity decreases with increasing conversion, and when p < jc the selectivity increases. This is illustrated in figure 3.9 for = 2, for p - jc = 1, and for p - jc = -1. 

In catalyst exploratory studies, one normally screens a wide variety of experimental catalysts with a standard feed. A catalyst that does not activate the most refractory portion of the feed might well be evaluated by a high-order kinetics. But if the performance of the catalyst is improved (for instance, by the incorporation of a more effective promoter) so that there is no longer a reffactory component, then a low overall order would have to be used in evaluating the improved catalyst. In process research work, one generally runs different feeds on a selected catalyst over a wide range of conditions. The overall reaction order is e3q)ected to increase when switching from an easy feed to a hard feed. The extent of this increase could be viewed as an index of feed refractoriness. The overall order is expected to... 

Crack-healing can be expressed as a function of oxygen partial pressure, P02, and healing temperature, T. For this purpose, two assumptions were employed. One is that the crack-healing rate, vh, which can be assumed to be the exponential function of P02, and the exponential index, corresponding to the reaction order of oxygen, are independent of temperature. The other is that the rate constant, which is a proportional constant of crack-healing rate versus n-th powered Poi, obeys Arrhenius law. 

The first reported controlled polymerization based on the OMRP-RT principle appears to have been presented by Minoura in a series of articles starting in 1978, where the redox initiating system BPO/Cr was used for the polymerization of vinyl monomers.Not only were the kinetics different than in free-radical polymerization (very low reaction orders in Cif and BPO), but also the polymerization was observed to continue after all Cr had been converted by the peroxide to Cr and the degree of polymerization was found to increase with monomer conversion at low temperatures (<30 0). These studies included the report of a block copolymer (PMMA-b-PAN). Polydispersity indexes were not reported for these studies. Minoura formulated the mechanistic hypothesis of the formation of a metal complex with the free radical and stated that "the recombination of free radicals formed by the dissociation of the complexed radicals competes with a disproportionation of free radicals". However, these studies did not have a great impact in the polymer community, being cited only a handful of times before 1994. A few subsequent contributions reported the application of similar conditions to other metals but well-controlled polymerizations were not found."- " ... 

Richardson-Zaki index, dimensionless Reaction order of the hydrocracking of vacuum residue Pressure, Pa... 

That is, k t/K,n is an apparent second-order rate constant ior the reaction of E and S to form product. Because A , is inversely proportional to the affinity of the enzyme for its substrate and is directly proportional to the kinetic efficiency of the enzyme, A , provides an index of the catalytic efficiency of an enzyme operating at substrate concentrations substantially below saturation amounts. 

This index is divided into two parts. Part 1 gives the names of compounds as used in these volumes as well as general terms for classes of compounds, types of reactions, synthetic applications, special apparatus, and unfamiliar methods. The complete names of all specific compounds are given in normal order as written in the text (e.g., ethyl cyano-acetate appears under ethyl). Some entries are common names and others are systematic Chemical Abstracts names, whichever was used in the text. 

In contrast to the quantity of solvent 1 used during the reaction, the quantity of extraction solvent 2 (work up) increases during scale up (Laboratory 100% Operation 103%), especially when it is related to substrate 2 (Laboratory 100% Operation 169%). Compared to the yield obtained from the literature protocol in which an extraction procedure is missing, an efficient extraction seems to be important in order to achieve sufficient product accumulation. However, as the mass index and the environmental factor demonstrate with respect to the possibility for reducing the volume of water used (see above), solvent 2 demand should be able to be reduced as well, since less water use means less solvent is required for extraction. StiU, at least the recycle rate of solvent 2 is as high as 72.8% (from 169% to 46%, Table 5.1), regarding the current data of the technical operation scale. 

The qualitative voltammetric behavior of methanol oxidation on Pt is very similar to that of formic acid. The voltammetry for the oxidation of methanol on Pt single crystals shows a clear hysteresis between the positive- and negative-going scans due to the accumulation of the poisoning intermediate at low potentials and its oxidation above 0.7 V (vs. RHE) [Lamy et al., 1982]. Additionally, the reaction is also very sensitive to the surface stmcture. The order in the activity of the different low index planes of Pt follows the same order than that observed for formic acid. Thus, the Pt(l 11) electrode has the lowest catalytic activity and the smallest hysteresis, indicating that both paths of the reaction are slow, whereas the Pt( 100) electrode displays a much higher catalytic activity and a fast poisoning reaction. As before, the activity of the Pt(l 10) electrode depends on the pretreatment of the surface (Fig. 6.17). 

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