Continuous Flow Hydrogenation of Nitrobenzene Over Palladium Catalyst in Microstructured Reactor Systems

Abstract

Hydrogenation of nitrobenzene to aniline is an important industrial reaction widely employed in the manufacture of dyes, pharmaceuticals, polymers, and specialty chemicals. The present study investigates the continuous flow hydrogenation of nitrobenzene over palladium catalyst in microstructured reactor systems under controlled operating conditions. The research focuses on evaluating reaction efficiency, catalyst performance, mass transfer characteristics, and process intensification associated with microreactor-based hydrogenation technology. Experimental analysis was conducted to examine the influence of reaction temperature, hydrogen pressure, flow rate, catalyst loading, and residence time on nitrobenzene conversion, aniline selectivity, and reactor stability. Results demonstrate that microstructured reactor systems significantly enhance gas–liquid–solid mass transfer and heat transfer efficiency, resulting in improved hydrogenation rates and stable reaction control. The study further reveals that palladium catalysts exhibit high catalytic activity and selectivity toward aniline formation while minimizing undesired side reactions and byproduct generation. Optimized flow conditions and reaction parameters contributed to enhanced conversion efficiency and reduced catalyst deactivation during prolonged continuous operation. Comparative assessment with conventional batch hydrogenation systems confirms the advantages of microstructured reactors, including improved process safety, lower reactant inventory, enhanced operational controllability, and reduced energy consumption. In addition, the compact reactor configuration supports process scalability and continuous chemical manufacturing applications.