Deactivation kinetic study on vapor phase Beckmann rearrangement of cyclohexanone oxime and design of the multi-layer inclined channel bionic reactor

Abstract

The optimal design of the reaction system of a large-scale industrial vapor phase Beckmann rearrangement of cyclohexanone oxime to caprolactam process requires both deactivation kinetics and reactor optimization. The deactivation kinetics was study in a micro fluidized bed reactor with online catalyst particle sampling system. An empirical coke formation rate equation was obtained based on time evolution of coke amounts. A Langmuir-Hinshelwood kinetics with deactivation factor based on coke amount was developed. Based on the obtained deactivation kinetics, a Multi-layer Inclined Channel Bionic Reactor was designed as a substitute of the conventional fixed-bed reactor. The hierarchical structure has four levels with inclined channel implementation in the third and fourth level to reduce the pressure drop and improve the flow distribution uniformity. The optimized massive structure of the Multi-layer Inclined Channel Bionic Reactor designed for 200 thousand tons of CPL productivity has a total pressure drop lower than 2kPa, and the maximal relative difference of the bed infiltration velocity is about 11 %.