Stanton-criterion

By dividing the reaction time by the thermal time constant, one obtains a dimensionless number, the modified Stanton criterion ... 

The modified Stanton criterion compares the characteristic reaction time with the thermal time constant of the reactor. The time can be eliminated from the equations by building the ratio ... 

This assessment criterion shows very clearly the fundamental difference between BR and SBR. Especially for the isothermally operated BR the example discussed has shown, that the ratio of Damkoehler to Stanton number should be significantly smaller than 1 to be sure of safe operating conditions. Exactly the opposite is required for the SBR. Semibatch reactors must be operated in an ignited state in order to be able to utilize the degree of heat production rate. Batch reactors have to be operated in the extinguished state with the consequence already outlined in Section 4.3.1.3, that they are suitable for slow and moderately exothermic processes only. 

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