Perfectly mixed flow reactors steady-state reactor design

Basic PFR equation Design equations Nonisothermal operation Perfectly mixed flow reactor (MFR) Basic CSTR equation Nonisothermal operation Multiple steady states MSS In a CSTR Adiabatic CSTR... 

We turn now to the plug flow reactor. Here, as we have said, there is absolutely no mixing in the direction of flow but perfect mixing perpendicular to it, that is, between the centerline and the walls. This special case of a tubular reactor can be operated transiently or in the steady state, but it is the latter mode that is most often considered for kinetics and design. Consider the reactor shown in Figure 4 in which A is converted to B irreversibly and with linear kinetics. 

The limiting cases of continuous reactors considered in most reactor design textbooks are the perfectly mixed stirred tank and the plug-flow tube. These reactors can differ significantly in the amount of mixing and, therefore, the residence time distribution. The plug-flow tube (PFT) is assumed to be without any axial mixing. Hence, at steady state, the residence time distribution of the material in the effluent stream is represented by the Dirac function as shown by Equation (8.1) ... 

Consider a feed stream (Figure 2.24) flowing at volumetric rate q, having a reactant A at concentration C o/ being fed into an ideal CSTR with constant fluid hold up V. Let C f be the concentration of reactant A in the outlet stream. The reactor is assumed to be at steady state. As the mixing is assumed to be perfect in the reaction vessel, uniformity in the concentration of A is achieved throughout the reactor volume and this concentration will be equal to the concentration of A in the outlet stream, that is, Q/- This assumption simplifies the design of an ideal CSTR, as discussed below. 

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