Vapor Phase Beckmann Rearrangement of Cyclohexanone Oxime to Caprolactam Over Silicalite Catalyst
Keywords:
Beckmann Rearrangement, Cyclohexanone Oxime, Caprolactam Production, Silicalite Catalyst, Vapor Phase Reaction, Catalytic Process EngineeringAbstract
The vapor phase Beckmann rearrangement of cyclohexanone oxime is an important industrial route for the production of caprolactam, a key precursor in nylon-6 manufacturing. This study investigates the catalytic conversion of cyclohexanone oxime to caprolactam over a silicalite catalyst under vapor phase reaction conditions with emphasis on reaction efficiency, selectivity, and catalyst performance. Experimental analyses were conducted to evaluate the influence of reaction temperature, feed flow rate, catalyst loading, residence time, and carrier gas composition on caprolactam yield and by-product formation. The silicalite catalyst exhibited high catalytic activity and strong selectivity toward caprolactam formation due to its unique pore structure, surface acidity, and shape-selective properties. Results demonstrated that optimized operating conditions significantly improved oxime conversion and minimized the formation of undesirable side products, thereby enhancing overall process efficiency. The vapor phase operation provided improved heat and mass transfer characteristics compared to conventional liquid-phase processes, contributing to stable reactor performance and reduced waste generation. Kinetic and mechanistic evaluations revealed that the rearrangement reaction is strongly influenced by catalyst surface interactions and diffusion behavior within the microporous silicalite framework. Catalyst stability studies indicated good resistance to deactivation and sustained performance during prolonged operation, supporting its suitability for continuous industrial applications. Furthermore, the proposed catalytic process offers environmental and economic advantages by reducing acid consumption and simplifying downstream purification requirements. The findings highlight the potential of silicalite-catalyzed vapor phase Beckmann rearrangement as an efficient and sustainable technology for caprolactam production in modern chemical manufacturing industries.
