Performance Characteristics for Micromixing Models

An important aspect of the micromixing models is that they define the maximum and minimum conversion possible for a given reaction and RTD. Zwietering (1959) showed that, for the reaction A - products, with power-law kinetics, ( -rA) = kAcA, 

The bounds for a complex reaction scheme in which the rate goes through a maximum or minimum, with respect to concentration, depend on the nature of the rate law and the desired fractional conversion. 

Micromixing may also have a major impact upon the yield and selectivity of complex reaction networks. Consider, for example, the following parallel reaction network, where both a desired product (D) and an undesired product (U) may be formed  

If both reactions are first order (a = j8 = 1), then micromixing is irrelevant yield, selectivity, and fractional conversion depend solely on the RTD. If, however, either a or /3 is not equal to 1, then the degree of micromixing can have a significant impact upon performance, as illustrated in the following example. 

Consider the following liquid-phase reactions, which occur in parallel  

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