Reactors for Series-Reaction Networks

A more specific comparison is between choice of a PFR and a CSTR to achieve the maximum concentration of B, cB max, at the reactor outlet, and the residence time, t, required. 

For a PFR, from Section 5.5, the residence time required to achieve c max is 

For a CSTR, from Section 18.3.2, the mean residence time (equal to the space time 

We compare the performance of a PFR and a CSTR from two points of view (1) the relative time required to achieve cB max, which is a measure of relative reactor size for a specified throughput, and (2) the relative value of CB 

In Table 18.1, values of RcBmax are given for K - 0, K = 1 and For this type of network, with normal kinetics, the performance of a CSTR cannot surpass that of a PFR that is, use of a PFR leads to a greater cB max at a smaller However, if the CSTR is staged, its performance can be closer to that of a PFR. 

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