Modelling of a microreactor for the partial oxidation of 1-butanol on a titania supported gold catalyst

Microreactors can provide more uniform operation conditions than conventional reactors due to the characteristic advantages related to mass and heat transfer. In our earlier research, a catalyst testing microreactor was used to study the gas-phase partial oxidation of 1-butanol to n-butyraldehyde and subsequently a Au/TiO₂ catalyst was selected for kinetic experiments and mathematical modelling in this work. Power law and mechanistic kinetic models were applied in parameter estimation using a 1D-pseudo-homogenous plug-flow reactor (PFR) model implemented in Matlab. In addition, a 2D model including dynamic mass balances for both the gas and solid catalyst phases with power law kinetics was implemented by using the process modelling tool gPROMS. The estimated activation energies and reaction rate constants were in physically meaningful order of magnitude. The activation energy for the partial oxidation of 1-butanol to n-butyraldehyde was found to be 77 kJ/mol. The predicted reactor performance results from the numerical simulations were in agreement with the experimental observations. The presented modelling approach can be used with more advanced mechanistic models involving surface species for the partial oxidation of 1-butanol. The model could in future be extended to optimize the yield of n-butyraldehyde for further process development.