Model of Diene Hydrogenation in Pyrolysis Gasoline

Abstract

A kinetic model of hydrogenation of a diene-olefin multicomponent reaction system, pyrolysis gasoline and the C4-hydrocarbon fraction was evaluated. Identification of kinetic constants of 18 individual reactions by a trial and error method was based on plant experiments carried out in a trickle-bed reactor of a DPG unit for selective hydrogenation of dienes using palladium / alumina catalyst CHEROX 40-05. All individual reactions were first order with respect to reaction components and the reaction system was described as pseudoisothermal (411 K). Simultaneous hydrogenation of all dienes and olefins in the feed made it possible to compare the double bond reactivities in dependence on molecular structure of individual hydrocarbons.Hydrogenation rates of the double bond decrease in the following order: vinyl group > conjugated double bond > double bond in a five-membered ring > trans double bond > cis double bond. A dicyclopentadiene depolymerization to cyclopentadiene and subsequent hydrogenation to cyclopentene were also observed.