Aqueous and\nBiphasic Coupling of Furfural and Cyclopentanone\nfor the Synthesis of Bio-Jet Fuel Precursors

We report on the aldol condensation of furfural and cyclopentanone\nin aqueous and biphasic mediums as a promising step for producing\nsustainable aviation fuel. Key parameters, including catalyst concentration,\nreactant concentration, temperature, and solvent, were found to significantly\ninfluence conversion and product selectivity. Alkaline conditions\nwere essential for aldol coupling, with significant conversion observed\nat pH 12 and higher. The activation energies for the formation of\nthe dimeric and trimeric aldol adducts were similar at 74 and 76 kJ/mol,\nrespectively. Biphasic conditions were employed to prevent product\nprecipitation, leading to reactor and equipment fouling. For biphasic\nconditions, the extraction of the reactants and dimeric intermediates\nto the organic phase affected rate and selectivity, resulting in the\ndilemma. Good product extraction leads to inevitable reactant extraction.\nBased on these findings, an integrated biphasic process design was\nproposed, utilizing process-owned solvents to optimize the separation\nand recycling of aqueous streams and improve the overall process efficiency.