Integral ratios, conversion

In addition to the experiments shown in Fig. 11.12a-c, we simultaneously increased NO and NO2 concenbations in the feed while holding the NH3 concentration fixed. NO and NO2 were fed in equimolar ratio while keeping the NH3 constant at 1,000 ppm and the feed gas devoid of O2. The data in Fig. 11.12d shows that the NOx consumption rate is an increasing function of the equimolar NOx feed. Moreover, a sigmoidal character to the data is apparent. As in the above-described experiments, the NO2 consumption rate exceeded that of NO. This bend is consistent with earlier results obtained for integral NOx conversion experiments. 

It is also possible to derive reactivity ratios by analyzing the monomer (or polymer) feed composition v.v conversion and solving the integrated form of the Mayo Lewis equation.10 123 The following expression (eq. 44) was derived by Meyer and Lowry 12j... 

Numerical approaches for estimating reactivity ratios by solution of the integrated rate equation have been described.124 126 Potential difficulties associated with the application of these methods based on the integrated form of the Mayo-kewis equation have been discussed.124 127 One is that the expressions become undefined under certain conditions, for example, when rAo or rQA is close to unity or when the composition is close to the azeotropic composition. A further complication is that reactivity ratios may vary with conversion due to changes in the reaction medium. 

Equation 27 can be numerically integrated along the conversion trajectory to obtain the Initiator concentration as function of time. Therefore, calculation of t, 6 and C together with the values of M, Rp, rw and rn from the equations In Table II allows the estimation of the ratios (ktc/kp1), (kx/kp) and the efficiency as functions of conversion. Figure 3 shows the efficiency as function of conversion. Figure 4 shows the variation of the rate constants and efficiencies normalized to their initial values. The values for the ratio (ktc/kpl)/(ktc/kpl)o reported by Hui (18) are also shown for comparison. From the definition of efficiency it is possible to derive an equation for the instantaneous loading of initiator fragments,... 

To produce 100 000 tonnes of nonanal per year (25% down time, 100% conversion of substrate, 80% selectivity to nonanal) requires a production rate from the reactors of 19 tonne h 1, so that each batch must be 6.3 tonnes. Assuming a 1 1 ratio by volume of fluorous solventdiquid substrate and a 75 % loading, each reactor must have a volume of 20 m3. If the distillation column were fully integrated into the system it would be required to handle 19 tonnes aldehyde h 1. An increase in selectivity to the linear product, which could be achieved using careful ligand design would reduce the reactor size by up to 25%. 

The total heat effect is obtained by similar experiments and calculations using Equation (3-18) discussed previously in Section 3.3.2.I. The total heat effect is the integral of qr over the reaction time. The conversion at any time during the reaction can be estimated from the ratio of the integral of qt to any time t over the total integral. Typically, chemical analyses show good agreement between calculated and chemically determined values. 

The ratio of the two pseudo-er a.r t ovasrs is accessible by simple integration of the respective peaks, which provides the ee and the E value (by use of an internal standard for conversion). The quantitative analysis can be accomplished automat-... 

The imaging of conversion within the fixed bed was achieved by using a distortionless enhancement by polarization transfer (DEPT) spectroscopy pulse sequence integrated into an imaging sequence, as shown in Fig. 44. In theory, a signal enhancement of up to a factor of 4 (/hZ/c 7i is the gyromagnetic ratio of nucleus i) can be achieved with DEPT. In this dual resonance experiment, initial excitation is on the H channel. Consequently, the repetition time for the DEPT experiment is constrained by Tih (< T lc) where Tn is the Ty relaxation time of... 

For a detailed analysis of monomer reactivity and of the sequence-distribution of mers in the copolymer, it is necessary to make some mechanistic assumptions. The usual assumptions are those of binary, copolymerization theory their limitations were discussed in Section III,2. There are a number of mathematical transformations of the equation used to calculate the reactivity ratios and r2 from the experimental results. One of the earliest and most widely used transformations, due to Fineman and Ross,114 converts equation (I) into a linear relationship between rx and r2. Kelen and Tudos115 have since developed a method in which the Fineman-Ross equation is used with redefined variables. By means of this new equation, data from a number of cationic, vinyl polymerizations have been evaluated, and the questionable nature of the data has been demonstrated in a number of them.116 (A critique of the significance of this analysis has appeared.117) Both of these methods depend on the use of the derivative form of,the copolymer-composition equation and are, therefore, appropriate only for low-conversion copolymerizations. The integrated... 

The imide conversion from poly (amic acid) to polyimide can be observed widi NMR spectrometry, as 6FDA/TFDB polyimide demonstrates excellent solubility. Figure 15.2 shows the dependence of imide conversion on curing temperature. The imide conversion is calculated by integrating the intensity ratio... 

Mann and Ko [202] likewise examined the selective oxidation of isobutene on bismuth molybdate. With an integral flow reactor, the highest selectivity was obtained at over 30% conversions for an oxygen/olefin ratio of 2/1 and a W/F = 2.5 g h mol-1 (390°C). The data were correlated with a rather complicated Langmuir—Hinshelwood expression inconsistent with a redox mechanism. This was based on a rate-controlling step between adsorbed isobutene and adsorbed oxygen, and included an inhibiting effect of methacrolein by competitive adsorption with isobutene, viz. 

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