Quadratic autocatalysis and self-heating in hydrocarbon oxidation

Griffiths, J. F.; Phillips, C.H.

doi:10.1039/f19898503471

Cited by 8 publications

(1 citation statement)

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“…In the process industries and applied science literature, much attention has been given to both experimental and theoretical aspects of 'thermal runaway' [I-31, or thermal explosion theory (TET) [4, 51. The system is considered to be well-stirred in the simplest form of this theory, i.e., there are assumed to be no temperature or concentration gradients within the reactants. This situation is realized by deliberate stirring of fluids either by jet-mixing in a flow reactor [q or by mechanical stirring in either a closed [7] or flow reactor [a]. It may also be approximately true in the case of gaseous reactions when a sufficiently high Rayleigh number prevails [9].…”

Section: Introductionmentioning

confidence: 99%

A novel, thermal instability in a ‘semi‐batch’ reactor

Gray

Coppersthwaite

Griffiths

1993

Process Safety Progress

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An unusual type of oscillatory, thermal instability in a reaction which takes place in a semi‐batch reactor, (i.e., when one reactant is admitted slowly to the reaction vessel and mixes with another reactant already present in the system) is investigated experimentally and theoretically. We show not only that oscillatory temperature changes may occur that are sufficiently large to constitute a formidable explosion hazard but also that the conditions under which such a hazard may take place could be entered unwittingly, in a mistaken belief that a move away from a potentially hazardous zone is being made. The theoretical background is formulated analytically in the context of a first order exothermic reaction. However, from the experimental study of the exothermic gaseous reaction between hydrogen and chlorine, we confirm the existence of oscillations and we show that the main features predicted by the simple theory transpose to more complex kinetic systems. In this particular system, temperature changes in excess of 200 K were measured in the unstable oscillatory region. The experimental study is linked to the theoretical foundations through numerical modelling of the non‐isothermal process, based on a detailed kinetic mechanism of the H2 + Cl2 reaction. Similar oscillatory phenomena are also shown by numerical simulation to be possible in a semi‐batch reactor in an exothermic reaction between two liquids.

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Section: Introductionmentioning

confidence: 99%