2020/08/05 by Arne Hommes, Bas Disselhorst, B.F. Disselhorst +1 · 2 citations
Engineering · Materials Science · Chemistry · #Innovative Microfluidic and Catalytic Techniques Innovation #Catalytic Processes in Materials Science #Oxidative Organic Chemistry Reactions
paper · pdf · doi:10.1002/aic.17005
Abstract Homogeneous Co/Mn/Br catalyzed aerobic oxidation of benzyl alcohol in acetic acid to benzaldehyde was performed in polytetrafluoroethylene microreactors operated under slug flow at temperatures up to 150°C and pressures up to 5 bar. Depending on the bubble velocity and length, a wetted or dewetted slug flow was observed, characterized typically by a complete or partially wetting liquid film around the bubble body. The latter flow suffered from a limited interfacial area for mass transfer. Experiments at temperatures up to ca. 90°C were under kinetic control given no product yield difference under wetted and dewetted slug flows and were used to establish a simplified kinetic expression (first order in benzyl alcohol and zero order in oxygen). This allows to develop a mass transfer model combined with an instantaneous reaction regime that well described the experimental results at higher temperatures where mass transfer was limiting in the dewetted slug flow.