(544dn) Modelling of Four Phase Continuous Hydrogenation Systems

The four phase reaction systems consisting of Gas-Liquid-Liquid-Solid(GLLS) phases are common in fine and specialty chemical industry. The addition of the fourth phase gives system specific benefits in terms of selectivity towards desired products and their separation. These reaction systems often involve complex reaction networks and selectivity towards desired product always poses challenges, especially while performing reactions in continuous mode of operation. In this work, a comprehensive reaction engineering model for four phase reactions has been developed by understanding the various factors affecting the performance of continuous reactors in terms of conversion and selectivity. The case of hydrogenation of Cinnamaldehyde to Cinnamyl alcohol was chosen. The generalised mixing cell approach with four phases (GLLS) interacting was developed. The model was written in general form for its application to different types of reactors. The previously determined intrinsic reaction kinetics for Cinnamaldehyde hydrogenation in same four phase system was integrated in this model. The model equations were solved in MATLAB and results were compared with laboratory scale data of Cinnamaldehyde hydrogenation reactions performed in fixed bed reactor and slurry reactor. The model was then used to develop insights and guidelines for enhancing selectivity towards desired product. The model will be useful for design and optimisation of similar GLLS reactors.