Calculation of the kinetics of deactivation by coke in an integral reactor for a triangular scheme reaction

The kinetics of deactivation by coke deposition has been studied for a SiO 2-Al 2O 3 catalyst in the isomerization of n-butenes in the 150-240°C temperature range. The kinetic model is a separable one, with a kinetic equation of the Langmuir—Hinshelwood—Hougen—Watson type for each one of the steps of the main reaction and of the deactivation reaction. The deactivation corresponds to the blockage of active sites by coke coming from degradation of cis-butene and trans-butene. The experimentation has been carried out in an isothermal integral reactor by working with a linear sequence of temperature—time. The treatment of the deactivation data for kinetic parameter calculation consists in rigorously solving the design equation for plug flow reactor; this method takes into account the effect of the composition of all the components on deactivation. The kinetic model has been verified by comparing the experimental results with those foreseen in the simulation of the isothermal operation and with different sequences of temperature-time. The procedure for both obtaining and analysing the deactivation kinetics data is particularly useful for complex reaction systems. In these systems, simplified methods for experimentation and calculation used to isolate the effect of composition on deactivation are not applicable.