CSTRs-In-Series CIS Model

In Chapter 4, we learned that the reaction rate disadvantage associated with a single CSTR can be reduced by putting several CSTRs in series. In fact, if the number of CSTRs is 

The CIS model is quite simple conceptually. A number iV of CSTRs are arranged in series. Each reactor has the same volume Vor contains the same weight of catalyst W. This configuration is shown schematically in the following figure. 

The CIS model and the Dispersion model are referred to as one-parameter models, since only a single parameter, D/uLot N, is used to characterize mixing. When there is very little mixing in the direction of flow, i.e., when A is large otD/uL is small, the physical basis of the Dispersion model is stronger than that of the CIS model. Moreover, when the number of CSTRs in series is large, it can be tedious to calculate the performance of the series of reactors. On the other hand, it is relatively straightforward to use even the most complex rate equations in the CIS model. It is not necessary to restrict the analyses to first-order rate equations. 

One disadvantage of the CIS model is that correlations do not exist that permit N to be predicted for given reactor configurations and flow conditions. For practical purposes, AT must be determined experimentally, via tracer response techniques, for each situation. 

The total volume of the V CSTRs N xV) should be the same as the total volume of the nonideal reactor that is being characterized. The total volume can be checked via tracer response techniques. If the mean residence time t in the vessel is measured, and if the vessel is closed,  

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