AR Theory for Batch Reactors

Up to now, the entire development of the AR, including theory and all supporting examples, have been based on the idea of continuous operation. (This is beeause classic AR theory was developed with continuous reaction in mind.) With the expansion of chemical engineering into biological, pharmaceutical, and other specialist industries, the modem process engineer is often confronted with problems related to batch operation. As a result, the ideas discussed so far are not useful unless they can be converted for use with batch reaction. 

In this section, we wish to briefly describe how a candidate AR, originally generated fi om continuous operation, may be transformed into an equivalent batch reactor stmcture, using simple conversion guidelines. This allows the use of the AR for both continuous and batch reaction. It is then possible to employ a single procedure to potentially optimize for two separate design scenarios. This approach allows for flexibility in design and analysis. 

Even though we wish to show that it is possible to attain steady state concentrations in a batch, it is not assumed that steady state itself can ever be attained. Batch processes, by their very nature, cannot achieve this. Hence, the outlook here will not be of the view that batch reactors, specifically fed-batch reactors, can ever be operated in any particular way that is able to reach 

Steady state. We would, however, like to demonstrate that it is still possible to achieve the specific concentration associated with that steady state. Certainly, this will require a special operating regime to achieve (which shall be detailed in the following sections), but this will always be with the intention that the reactor is operated under bateh conditions—that is, with a distinct cycle time where the state variables of the batch reactor (volume, concentration, etc.) do, in fact, vary for the duration of this period. 

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