Solvent-free biocatalytic synthesis of 2,5-bis-(hydroxymethyl)furan fatty acid diesters from renewable resources

Fatty acid diesters of 2,5-bis-(hydroxymethyl)furan (BHMF), promising candidates as sustainable bioadditives, increasing the cetane number of biodiesel fuels, were prepared through a solvent-free Novozym 435 mediated diesterification of BHMF with the fatty acid mixture (FAM) resulted from the hydrolysis of commercial sunflower oil. Under solvent-free conditions and a 15 mbar vacuum, high conversions into diesters were obtained in the heterogeneous reaction, after the gradual solubilization of BHMF. After optimization studies (temperature, reaction time, BHMF- FAM ratio and biocatalyst loading), more than 97% conversions into diesters were achieved. The calculated sustainability metrics supports that the currently described solvent-free method represents an improved synthetic procedure for BHMF fatty acid diesters preparation.