The explosion in the shell fluoromatics plant at Stanlow, March 1990. An investigation of the underlying chemistry

Abstract The explosion in the Halex reactor of the Stanlow Fluoroaromatics Plant has been investigated by thermochemical studies, analytical and chemical work and computer modelling. The conclusion is that an exothermic runaway reaction occurred, due to contamination of the solvent with acetic acid. This had been formed a few days before the explosion by a water leakage in a different section of the plant, causing partial hydrolysis of the solvent. Acetic acid completely changes the normal course of the Halex reaction; a novel, exothermic reaction occurs, the mechanism of which has been elucidated. Under adiabatic conditions this exotherm causes a rapid temperature rise to 230–250 °C, at which point explosive decomposition occurs due to the presence of a nitrocompound.