Catalytic production of long-chain hydrocarbons suitable for jet-fuel use from fermentation-derived oxygenates

The present review encompasses the recent advances that have been carried out in the last years for the production of long-chain hydrocarbons from fermentation-derived compounds such as acetone, butanol and ethanol (ABE mixtures), among others, as a solution for obtaining product mixtures suitable for use as sustainable aviation fuels. An insight on the reaction pathways is given for the different processes that take place: alkylation of ketones with organic alcohols, self-condensation (Guerbet reaction) of alcohols, oligomerization of ketones and hydrodeoxygenation (HDO) of the products. A summary of the recent catalytic developments is provided, focusing first on palladium-based catalysts as the benchmark catalyst that has traditionally been used for this purpose, then addressing other novel catalytic systems aiming to replace palladium and final insights on the different strategies to carry out HDO after alkylation. There is a special focus on the use of ABE mixtures as starting reagents, as the coupled functionality between acetone and the two organic alcohols turns out to be especially suitable for these processes.