Reactions with two reactants

Second-Order Batch Reactions with Two Reactants. The batch reaction is now... 

Solution This can be done by substituting the various rate equations into Equation (1.36), integrating, and applying the initial condition of Equation (1.37). Two versions of these equations can be used for a second-order reaction with two reactants. Another way is to use the previous results for... 

If we consider the irreversible reaction with two reactants forming a product... 

In later sections, reactions with two reactants are discussed in which the reaction rate depends on the concentrations of both reactants ... 

The next type of reaction considered is an exothermic reversible reaction with two reactants and two products ... 

As a numerical example, we consider a gas-phase exothermic irreversible reaction with two reactants and one product that occurs in a PFR packed with a solid catalyst ... 

Ex. 4 A second order reaction with two reactants is started with 0.1M concentrations of each reactant. It is 20% completed in 500 seconds. How long will it take the reaction to go to 70% completion ... 

Fig. 12.1. Dependence of conversion on Damkohler number for a) a first-order reaction (Eq. (13)) b) a second-order reaction (Eq. (14)) and c) a second-order reaction with two reactants and a nonstoichiometric feed composition (Eqs. (15) and (16), here for X = 0.5).

To obtain experimental data suitable for the determination of kinetic parameters, two different operation modes of reactors should be considered, the differential and the integral mode. In the differential mode rates are calculated from small conversions (<10%) within a fixed time span dt. For reactions with two reactants, it is suitable to use excess of one reactant to suppress undesired side reactions. 

Other reaction orders The overall reaction order of a chemical reaction is the sum of the orders for the individual reactants in the rate law. Many chemical reactions, particularly those having more than one reactant, are not first order. Consider the general form for a chemical reaction with two reactants. In this chemical equation, a and b are coefficients. 

We continue the analysis of gaseous, variable-volume batch reactors and consider now chemical reactions with two reactants of the general form... 

Reactions with Two Reactants. Numerous reaction types (see Table I) are possible in the case of two reactants. In some cases, several reaction classes need to be considered for two reactants. Consider the case of FeFo and Cr(HC0g)2> which may be an improbable set of reactants but which illustrates nicely the operation of the expert system. 

Second-order reactions with two reactants are common ... 

For a second-order reaction with two reactants, 01 = = —kab. Write two versions... 

Table 1.2 summarizes the design equations for elementary reactions in ideal reactors. Note that component A is the only component or else is the stoichiometrically limiting component. Thus a = alao for batch reactions and a = afor flow reactors and Ya = a in both cases. For the case of a second-order reaction with two reactants, the stoichiometric ratio is also needed ... 

Alkylation of mixed cresols using isobutylene, co-oxidation of cyclohexane and acetaldehyde, and chlorination of mixed xylenols are examples of gas-liquid organic reactions in which absorption of a gas is followed by reaction with two reactants in the liquid. This class of reactions can be represented as... 

In CSTR experiments, inlet concentrations and space times have to be varied over a wide range, using several different nonstoichiometric feed compositions. If reactant concentrations are varied in stoichiometric ratios for a reaction with two reactants, the overall reaction order a+P) is determined from experimental data rather than the individual orders of a and p for reactants A and B, respectively. The disadvantage of a CSTR is that the exit reactant concentrations have to be controlled by manipulating the inlet concentration and the space time by a trial-and-error routine, which is difficult at times when more than one reactant is involved [23]. 

An overall homogeneous chemical reaction takes place in the catalytic bed of the porous reactor. We assume a simple first-order reaction with two reactants A and B, which results in a product C written as... 

Let us now consider the important case of a second order reaction with two reactants, with kinetics described by eq. (3.4). We can write the mass balances, combined with the rate equation, as follows (assuming constant density)... 

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