Etherification of hydroxymethylfurfural with ethanol on mesoporous silica catalysts of regulated acidity to obtain ethoxymethylfurfural, a bio-additive for diesel

Abstract

5-(hydroxymethyl)furfural (HMF) obtained from biomass can be etherified with ethanol to 5-(ethoxymethyl)furfural (EMF), a promissory bio-additive for diesel, employing solids with suitable acidity and porous structure as catalysts. The performance of MCM-41 and SBA-15, with different amount of sulfonic acid sites (-SO3H), was compared at 140 °C in a batch stirred reactor. 10 g L−1 of SBA-15 with a 0.054 S/Si molar ratio gave HMF conversion of 94.6% and EMF yield of 76.5% after 3 h of reaction from a 15 g L−1 of HMF/ethanol. The catalyst preserved its activity over 4 reaction cycles; reaching HMF conversion of 78.0% and EMF yield of 68.7%. From 90 g L−1 of HMF/ethanol and 20 g L−1 of catalyst achieve a HMF conversion of 94.3% and an EMF yield of 89.3% in 1.5 h of reaction (rate of 69.1 g L−1 h−1). A scale-up of production to a continuous reactor could be considered.