Esterification of furfuryl alcohol to butyl levulinate over ion-exchange resins

•Accessibility to acid centers conditions the activity of ion-exchange resins.•Gel-type resins activity can be related to the specific volume of the swollen polymer.•Stiff macroreticular resins activity can be related to permanent porosity.•Low crosslinked macroreticular resins are best catalysts for this reaction.•Furfuryl alcohol polymerization is more affected by concentration than temperature. The esterification of furfuryl alcohol with 1-butanol was successfully tested at low initial butanol/furfuryl alcohol molar ratio values (4 and 8) in the temperature range 80–110 °C over different ion-exchange resins. The polymerization reaction of furfuryl alcohol also occurs, being more affected by the initial 1-butanol to furfuryl alcohol molar ratio than temperature under the conditions tested. The accessibility to acid centers conditioned the activity of ion-exchange resins. While for gel-type resins this can be related to the specific volume of the swollen polymer, for macroreticular resins there is a compromise between permanent porosity (for stiff resins) and the existence of a very flexible gel-phase zone for low crosslinked macroreticular resins. The maximum yield to butyl levulinate obtained was 63% at 110 °C and a molar butanol/furfuryl alcohol ratio of 8 on the macroreticular resin Amberlyst 39.