Case A. Continuous Stirred-Tank Reactor CSTR

1 Case A Continuous Stirred-Tank Reactor (CSTR) 

The material balance for a continuous-flow, stirred-tank reactor with constant volume and first-order reaction is 

Dividing the balance equation by the volume of reactor, V, leads to the equation in the form 

This equation has two parameters t, the mean residence time (r=V/F) with dimensions of time and k, the reaction rate constant with dimensions of reciprocal time, applying for a first-order reaction. The concentration of reactant A in the reactor cannot, under normal circumstances, exceed the inlet feed value, CA0, and thus a new dimensionless concentration, CAi, can be defined as 

The other variable time, t, can vary from zero to some undetermined value, but the system is also represented by the characteristic time, t. Note that the value of 1/k also represents a characteristic time for the process. 

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