Self-heating, Chemical Kinetics, and Spontaneously Unstable Systems

Self heating, Chemical Kinetics, and Spontaneously Unstable Systems 

In this Report the overall thermokinetic behaviour of chemical reactions is discussed wdth special reference to the stability of exothermic reactions. An almost universal property of such systems is the existence of more than one distinct mode of reaction, and hence of the possibility of sudden switches between different modes. Thus, starting from given initial conditions of temperature and pressure, a reaction may proceed at a constant low velocity (or one varying only slowly with time), whilst slightly different initial conditions lead to violent acceleration and explosively rapid change. The division between the two regimes is often distinct and well defined. Here, interest centres on the criteria that determine the onset of spontaneous ignition in exothermic systems and on the possibility of quantitative and qualitative interpretation and prediction of the features observed. 

The arrangement of this Report takes the form of six questions which have 

English Edn., Princeton University Press, 1955 (h) 2nd Edn., Plenum Press, New 

Discussions in this Report will be inincipally concerned with work published since 1965. We exclude such heterograieous reactions as the combustion of carbon or the catalytic oxidation of ammonia and such intoisdy localized ignitions as diose due to sparks, hot wires, friction, ot shock. Attrition is chiefly directed to gaseous reactions in closed systems but a survey of recent relevant work on umteady bdiaviour (ignition, extinction, and oscillations) in open systrans is also included. 

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