Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

OP-III-22MATHEMATICAL MODELLING OF THE ETHYLENE GLYCOLOXIDATION PROCESSM.A. Salaev, A.A. Krejker, O.V. Magaev, A.S. Knyazev,E.S. Borisova*, V.M. Khanaev*, O.V. Vodyankina, L.N. KurinaTomsk State University, 36, pr. Lenina, 634050 Tomsk, Russia, Fax: (3822) 52-95-85* Boreskov Institute of Catalysis, 5, pr. Akademika Lavrentieva, 630090 Novosibirsk, Russiae-mail: vodyankina_o@mail.ruHeterogeneous catalytic oxidation of alcohols is one of the most important methods ofsynthesis of such valuable carbonyl compounds as formaldehyde, acetaldehyde, acetone,propionic aldehyde, phtalic aldehyde, etc. Glyoxal, one of the most important products ofmodern industry, can be synthesized by partial oxidation of ethylene glycol. This aldehyde isused in wood-working, tanning, pharmaceutical, paper and many other industries.Industrial production of glyoxal is generally carried out by vapor-phase oxidation ofethylene glycol over copper, silver and complex Cu-Ag catalysts [1]. New catalytic systemsfor this process based on silver nanoparticles were developed at the Laboratory of catalyticresearches of Tomsk state university. These catalysts show high activity and thermal stability,and are perspective for using in industry.The aim of the present work is to develop a mathematical model of the ethylene glycoloxidation process, allowing the optimization of the process conditions, and prediction thebehavior of the reaction system.Experimental data of the process realization, taken for model development, were obtainedaccording to [Ошибка! Закладка не определена.]. The investigations were carried out incontinued-flow fixed bed reactor (reactor length was 100 mm), the temperature span was 500-650 °С. In each experiment the temperature profile along the reactor under steady operatingconditions was measured and recorded. Liquid and gas products of the reaction were analyzedchromatographically. Mathematical processing of the experimental results was performedwith using of HYSYS program.The following statements were used during the development of the mathematical model:(1) the ethylene glycol oxidation process is realized in the external diffusion mode; (2) bothoxidation reactions of glyoxal into CO and water, and CO into СО 2 , as well as water-gasshift-reactiontake place on the catalyst surface in the kinetic mode.To calculate the heat balance the time-dependent equation of heat transmission over thesolid phase of the catalyst bed was used. General heat exchange coefficient was calculatedaccording to the quasi-homogeneous model of tubular reactor [2-3]. The maximal temperatureat the centre of the catalytic bed was estimated by the determination of the heat exchangecoefficient as a function of both Bio parameter and coefficient of heat exchange with the133