Thermokinetic Oscillations in Gaseous Systems

Abstract

This plenary lecture is a response to the Organizing Committee's request for a survey (i) of some of our own research in the field of oscillatory oxidation processes and (ii) of thermokinetic oscillations in a wider context. I shall accordingly deal with those systems in which the oscillatory behaviour springs from true reaction kinetic flexibility [1, 2] plus thermal feedback, rather than with those thermochemical oscillations [3] that really owe their existence wholly to sustained flow. Accordingly, the principal experimental themes to be pursued are (i) the oscillations found in the oxidation of hydrocarbons and related organic species, including the famous oscillatory cool flames, and (ii) the oscillatory oxidation of “wet” carbon monoxide. Both these reactions show oscillatory behaviour in closed vessels [1], so they are not simply artefacts of flowing conditions, but I shall here dwell on newer results that we have found in open systems. That will prompt some observations on the relationships between thermodynamically closed and open systems, and later raise some general questions about definitions or at least about more careful use of common terms (and a plea to do away with jargon).

Multiplicity and instability of states for isothermal homogeneous reactions in CSTR: Case of autocatalysis

“…in chemical reactors are known to occur in homogeneous as well as heterogeneous systems both under isothermal and nonisothermal conditions. The significant developments in the area have been summarized in several recent papers and reviews (Noyes, 1980;Gray, 1980;Uppal et al, 1974;Slinko and Slinko, 1978;Schmitz, 1978). Instability in solid catalyzed reactions under isothermal conditions is generally the result of surface dynamic effects (Belyaev et al, 1974;Pikios and Luss, 1977;Dagonnier and Nuyts, 1976).…”