EXPLOSION IN THE SHELL FLUOROAROMATICS PLANT AT STANLOW, MARCH 1990 - AN INVESTIGATION OF THE UNDERLYING CHEMISTRY

The explosion in the Halex reactor of the Stanlow Fluoroaromatics Plant has been investigated by thermochemical studies, and by analytical and chemical work. It is concluded that an exothermic runaway reaction occurred, due to contamination of the solvent with acetic acid. This acid had been formed a few days before the explosion, after water had leaked into a different section of the plant, causing partial hydrolysis of the solvent. Acetic acid completely changes the 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-degrees-C, at which level an explosive decomposition occurs due to the presence of a nitro compound.