Dehydrogenation of n-Butane to Butadiene-1,3 on Aluminochromium Catalyst. Part 2: Formulating a Mathematical Model of the Reactor

The authors formulate a mathematical model of the non-stationary single-stage dehydrogenation of n-butane to butadiene in an adiabatic fixed-bed reactor for the first time, based on a kinetic model that describes the formation of coke and primary and secondary by-products on a K-CrOx/γ-Al2O3 catalyst. The model allows prediction of the yield of butadiene and other products depending on the activity of the catalyst, the composition of initial mixture, the period of the dehydrogenation cycle, and the degree of catalyst dilution with an inert material (including the non-uniform dilution of a catalyst with an inert material along the bed length). It also allows assessment of the temperature regime of the catalyst’s operation and the degree of its coking along the bed. It is shown that the model is adequate for describing the conversion of n-butane, the formation of butadiene and butylene, the accumulation of coke, and the loss of catalyst activity using test calculations of main technological parameters as an example.