Oscillatory thermal instability and the Bhopal disaster

Abstract

Thermal runaway reactions were involved in the Bhopal disaster of 1984, in which methyl isocyanate was vented from a storage tank of the liquid, and oc-cur in liquid peroxide explosions, yet to date there have been few investigations into the mechanism of thermal runaway in such liquid thermoreactive systems. Consequently protocols for storing thermally unstable liquids and deactivating liquid bombs may be suboptimal. In this work the hydrolysis of methyl iso-cyanate and the thermal decomposition of triacetone triperoxide were simulated using a gradientless, continuous-flow reactor paradigm. This approximation en-abled stability analyses on the steady state solutions of the dynamical mass and enthalpy equations. The results indicate that thermal runaway in both sys-tems is due to the onset of a large amplitude, hard thermal oscillation initiated at a subcritical Hopf bifurcation. This type of thermal misbehaviour cannot be predicted using classical ignition theory, and may be typical of liquid ther-moreactive systems. The mechanism of oscillatory thermal instability on the nanoscale is elucidated