Experimental and modelling study of partial oxidation of ethanol in a micro-reactor using gold nanoparticles as the catalyst

A microreactor was used to oxidize ethanol to valuable products under atmospheric pressure. Nano-sized gold on alumina was used as heterogeneous catalyst in the microreactor. A uniform and stable catalyst coating in the microchannels was achieved by suspension method. The catalyst was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray analysis, nitrogen-physisorption and X-ray diffraction. The reaction system was studied by changing the operation conditions, i.e. the residence time and temperature (100–250 °C). The product stream was analyzed by on-line gas chromatography. The identified products were acetaldehyde, ethyl acetate, diethyl ether and ethylene. The aim of the study was to find out the operation conditions that favored the generation of the desired product. A detailed modelling work was included. A kinetic model was developed for the reaction system. Dynamic mass balance-based generic modelling was applied to estimate the rate parameters. gPROMs ModelBuilder, a highly advanced process modelling tool was used. The obtained selectivity for acetaldehyde formation was around 90% already at low temperatures. The mathematical model described the ethanol conversion and acetaldehyde selectivity very well. The experimental equipment, the catalyst, and the modelling approach are applicable for other gas-phase oxidation studies.