Reactor stability and safe reaction engineering

Abstract

Stable operation of a chemical reactor and stability (in the stability-theory sense) of a chemical process are not necessarily synonymous concepts. Thus, appropriate control can permit reliable operation at an unstable operating point, while even global stability does not necessarily rule out a runaway reaction, e.g., when a strongly exothermlc reaction has a pronounced parametric sensitivity. The concepts of stability and parametric sensitivity are explained in relation to strongly exothermic reactions in stirred-tank and tubular reactors. The conventional view of reaction engineering and the theory of thermal explosions, commonly used in safety engineering, are considered in detail. Practical problems of safe reaction engineering are discussed in relationship to the control of batch and semibatch reactors and to the behavior of tube-bundle reactors.