Production of renewable mesitylene as jet-fuel additive: Reaction kinetics of acetone self-condensation over basic (TiO2) and acid (Al-MCM-41) catalysts

Abstract

Sustainable production of jet fuel additives plays an essential role to decrease greenhouse gas emissions in the aviation industry. Acetone obtained from biomass fermentation is one of the platform molecules of the bio-refinery that can be used as raw material of newly developed sustainable processes. Mesitylene jet fuel additive can be obtained by acetone self-condensation reaction catalyzed by porous solids. In the present work, TiO₂ and Al-MCM-41 have been chosen, respectively, as basic and acid catalysts, because of having some tolerance to deactivation. The reaction was studied in a continuous fixed-bed reactor operated in the gas phase at space velocities of 7900 mol/kg h for TiO₂ and 5000 mol/kg h for Al-MCM-41. The influence of feed concentration (5–20% acetone and 0–5% mesityl oxide) and temperature (200–350 °C) was studied. First, the reaction scheme was assessed based on the product distribution. It was found that the acid catalyst Al-MCM-41 favors mesityl oxide decomposition to undesired isobutylene and acetic acid. Then, a mechanistic kinetic model of the different steps of the reaction scheme was developed and fitted the experimental results of each catalyst. This model constitutes a valuable tool for the scale-up of this process.