Synthesis of Oxygen-Containing Precursors of Aviation Fuel via Carbonylation of the Aqueous Bio-oil Fraction Followed by C-C Coupling

The aqueous fraction of bio-oil from biomass fast pyrolysis mainly contains low-molecular-weight oxygenates such as carboxylic acids, ketones, aldehydes, phenols, and furans. In this study, the full components of aqueous bio-oil are directionally converted into carbonyl groups such as aldehydes and ketones, and then the oxygen-containing precursors of aviation fuel are prepared through coupling, focusing on exploring the mechanism of carbonylation and C-C coupling. Studies have revealed that propionic acid, furfural, and phenol can be directionally converted into ketones, in which reaction 3-pentanone, cyclopentanone, and cyclohexanone were formed via ketonization and hydrogenation in the aqueous phase. Then the two components of 3-pentanone, cyclopentanone, cyclohexanone, acetone, and acetaldehyde were subjected to aldol condensation to explore the C-C coupling mechanism in the preparation of the C-7-C-18 precursor of aviation fuel. The mechanism in the high-quality utilization of all components of the aqueous phase bio-oil fraction was explored, which was favorable for the synthesis of biomass-based aviation fuel.