Second-order reactions competitive-consecutive

ILLUSTRATION 5.6 DETERMINATION OF REACTION RATE CONSTANTS FOR COMPETITIVE CONSECUTIVE SECOND-ORDER REACTIONS... 

A procedure for analyzing competitive, consecutive second-order reactions of the type ... 

It was early reported12 that the action of hexyne-1 on diethylmagnesium in solvent diethylether proceeded by the two competitive consecutive second-order reactions (12) (R = Et) and (13) (R = Et). 

The difficulties over the constitution of organomagnesium compounds mentioned above, prompted Abraham and Hill22 to study the kinetics of acidolysis of reactive organometallic compounds of well-defined constitution. Dialkylzincs are monomeric substances23 which may be purified by distillation, and should therefore be more suitable substrates. Acidolysis of di- -propylzinc by the weak acids p-toluidine and cyclohexylamine at 76 °C in solvent diisopropyl ether was shown to follow kinetics compatible with the two competitive consecutive second-order reactions (15) (R = Pr", R = p-tolyl or cyclohexyl) and (16) (R = Pr", R = p-tolyl or cyclohexyl),... 

The accuracy of low-dimensional models derived using the L S method has been tested for isothermal tubular reactors for specific kinetics by comparing the solution of the full CDR equation [Eq. (117)] with that of the averaged models (Chakraborty and Balakotaiah, 2002a). For example, for the case of a single second order reaction, the two-mode model predicts the exit conversion to three decimal accuracy when for (j>2(— pDa) 1, and the maximum error is below 6% for 4>2 20, where 2(= pDd) is the local Damkohler number of the reaction. Such accuracy tests have also been performed for competitive-consecutive reaction schemes and the truncated two-mode models have been found to be very accurate within their region of convergence (discussed below). 

In the paper by Paul Treybal.thev showed that the reaction products of a competitive, consecutive second order reaction do depend on the RMS fluctuation value at the injection point. 

C.T.Chen, The Kinetic System Consisting of Two Pairs of Competitive Consecutive Second-Order Reactions, The Journal of Physical Chemistry,... 

W.J.Svirbely, The Kinetics of Three-step Competitive Consecutive Second-order Reactions, Journal of the American Chemical Society, 81,255-257(1959). 

ILLUSTRATION 5.6 Evolution of Species Concentrations for Competitive-Consecutive Second-Order Reactions Occurring in a Batch Reactor... 

Figure 15.6 Speciation plots for the competitive-consecutive second-order reactions of ammonia and ethylene oxide in a batch reactor to form mono-, di-, and tnethanolammes (MEA, DEA, and TEA).

ILLUSTRATION 9.5 Trajectories of Product Concentrations with increasing Reactor Space Time for Competitive-Consecutive Second-Order Reactions in Continuous-Fiow Reactors... 

Paul, E. L. and R. E. Treybal (1971). Mixing and product distribution for a liquid-phase, second-order, competitive-consecutive reaction. AIChE Journal 17, 718-724. 

Paul, E. L., and Treybal, R.E. "Mixing and Product Distribution for a Liquid-Phase, Second-Order, Competitive-Consecutive Reaction", presented at 62nd Annual Meeting A.I.Ch.E., Washington, D. C. (November 1969). 

Viewed from the perspective of ethylene oxide, these reactions are competitive by contrast, from the perspective of the amines, they are consecutive. Consider a research scale batch reactor operating at 60°C and 20 bar to maintain all species in the liquid phase. Actual production of these commodity products on a large scale would be conducted in flow reactors, as described in Illustration 9.5. The rate laws are of the mixed second-order form (first-order in each reactant), with hypothetical rate constants ki, k2, and equal to 1,0.4, and 0.1 L-moCV min, respectively. MEA and DEA are both high-volume chemicals, while TEA is less in demand. The distribution of alkanolamine products obtained under the specified conditions can be influenced by controlling the initial mole ratio of EO to A and the time of reaction. 

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