Production of Sustainable Aviation Fuels (SAF) from vegetable oils and animal fats via non-catalytic photodecarboxylation

Abstract

The transition toward low-carbon fuels demands efficient routes for converting renewable feedstocks into drop-in hydrocarbons. In this work, we report an alternative, metal-free photodecarboxylative protocol for the production of hydrocarbons within the Sustainable Aviation Fuel (SAF) range, starting from N-hydroxyphthalimide-derived redox-active esters obtained from C10-C18 fatty acids. The methodology relies on the in situ formation of an electron donor-acceptor (EDA) complex between the redox-active ester and the Hantzsch ester, which simultaneously acts as a hydrogen atom donor and photochemical activator, thereby eliminating the need for metal catalysts and molecular hydrogen. Under visible-light irradiation, at ambient temperature and atmospheric pressure, using isopropyl alcohol as solvent, saturated substrates achieved conversions exceeding 99% and afforded the corresponding n-alkanes (C n-1 ) in yields of up to 83%. Chain-length variation influenced the overall efficiency, providing C 9 -C 17 alkanes in yields ranging from 52 to 83%. Unsaturated C 18 substrates furnished the corresponding olefins in moderate yields (up to 48%). The one-pot strategy maintained conversions above 90% and enabled the direct application of the protocol to a range of real lipidic biomasses, delivering overall yields between 31 and 79%. The protocol operates under mild conditions, tolerates open-air atmosphere, and can be driven by solar irradiation, representing a promising alternative to conventional SAF production pathways.