First order reactions in series

The kinetics observed are typical of two first-order reactions in series. 

If the two steps of first-order reactions in series have very different values for their rate constants, we can approximate the overall behavior as follows ... 

Table 18.2 The Role of Diffusion in Pores for First-Order Reactions in Series...

Consider a first order reaction in series as A— - B—>C. The rate equations for a constant volume batch system (i.e., constant... 

Figure 7.3 also compares the evolution of the concentrations of the intermediate Q and the product in case of two first-order reactions in series in a CSTR with that in a batch or plug flow reactor. For constant density, the mass balance for the reaction components in a CSTR are ... 

The dehydrogenation of n-butenes, diluted with steam, on a Shell 205 catalyst can be described approximately by two first-order reactions in series (A B C) ... 

Figure 4.11 Two first-order reactions in series in a batch reactor,...

For consecutive reactions where the intermediate is the desired product, the local selectivity and the maximum yield are decreased because of the concentration differences between the bubble phase and the dense phase. Consider the simple case of two first-order reactions in series, and assume Model II is applicable ... 

Figure 4.3.5 First-order reactions in series (A- B- C) course of the concentrations of reactant A and products B and C for different ratios hi/k2 (cc = 0.5ca,o for t = ty, Cb.o = cc,o = 0, constant volume, batch reactor). Adapted from Baerns et al. (2006).

For two first-order reactions in series (A- B C) taking place in a porous catalyst plate with thickness 2L [rate constants k , j and k 2 (m kg cat s )], the differential equations for the reactant A (feedstock) and the intermediate B are ... 

Influence of Reactor Type on Product Yields and Selectivity Let us consider two first-order reactions in series A—C. In batch and plug flow reactors, the yield of intermediate B is given by Eq. (4.3.39), derived in Section 4.3.2.1 ... 

It has been stated by Boudart that the steady-state approximation (SSA) can be considered as the most important general technique of applied chemical kinetics [9]. A formal proof of this hypothesis that is applicable to all reaction mechanisms is not available because the rate equations for complex systems are often impossible to solve analytically. However, the derivation for a simple reaction system of two first-order reactions in series demonstrates the principle very nicely and leads to the important general conclusion that, to a good approximation, the rate of change in the concentration of a reactive intermediate, X, is zero whenever such an intermediate is slowly formed and rapidly disappears. 

Problem 8-4 (Level 3) A pilot plant is being operated to test a new catalyst for the partial oxidation of naphthalene to phthalic anhydride. The chemistry of this process can be approximated as two first-order reactions in series ... 

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