Modelling Approach to the Evaluation of Explosion Limits of Ethylene-Air Mixtures at Flowing Conditions for Industrial Process Optimisation

Abstract

Hydrocarbon partial oxidation is still one of the most hazardous processes in the chemical industry, requiring the correct knowledge of the explosive limits under flowing industrial conditions. Well-known industrial applications in which ethylene at the vapour phase is oxidized with oxygen are the manufacture of vinyl acetate and of ethylene oxide. Partial oxidation of ethylene is usually performed at elevated temperature and pressure in multi-tubular cooled reactors where the application of explosive limits experimentally obtained under stagnant conditions could entail a not justified economical handicap. Bearing in mind these considerations, in this paper we developed a novel physical-mathematical model to predict the ignition and flame propagation phenomena in the presence of gaseous explosive mixtures The explicit formulae for the ignition condition and the transition from local reaction to fully developed explosion were obtained by exploring a broad range of operative conditions. A fairly good agreement was evidenced between the predictions of the oxygen critical concentration corresponding to the explosion point and previous experimental studies performed by different researchers.