A mathematical model of heating of a reaction mixture in the process of vacuum dehydrogenation of hydrocarbons

Abstract

Dehydrogenation (reaction of splitting hydrogen from the molecule of an organic compound) is one of the most important reactions of organic synthesis. The process is used to obtain both end-products and hydrocarbons that actively enter into other reactions, for example, polymerization. The dehydrogenation process is used in the production of styrene, isoprene, and butadiene [1]. The use of a vacuum to reduce the partial pressure of the initial substances in the course of the reaction promotes the yield of end-products as well as substantially reducing their cost by avoiding the use of high-voltage and expensive heating steam, which is used to reduce the partial pressure of the initial mixture, and also by making it possible to conduct the dehydrogenation reaction in a single stage [2]. In the present article, a mathematical model of the heating of an initial mixture for dehydrogenation of hydrocarbons in a vacuum is constructed. n-butane was selected as the initial mixture for the calculation; heating of the compound was performed by means of an electrical current in the tubular reactor of an experimental vacuum dehydrogenation plant [3]. A special feature of the problem is that heating of the gas is accomplished under the conditions of a vacuum; the properties of gases at low pressures are described by molecular-kinetics theory and the general approach to the solution of the problem may lead to substantial computation errors [4].