Catalytic Conversion of Sugars from Coffee Waste and Xylose into Furfural over Fe/SiO2 Catalysts

Solid Fe catalysts supported on SiO2 with Lewis and Brönsted acidity were synthesized using the sol-gel methodology. FTIR spectroscopy, XRD, Raman spectroscopy, BET isotherms, and SEM characterized the materials. Subsequently, they were used to dehydrate xylose to obtain furfural. It was observed that increasing the metal loading from 0.5 % to 1.5 % by mass increases the selectivity to furfural up to 40.09 %; in addition to this, it was observed that the calcination temperature has an effect concerning the conversion since the materials calcined at 450 °C present higher xylose conversion concerning the materials calcined at 750 °C. Finally, it was observed that the catalysts are active and effective in obtaining furfural from hydrolysates obtained from hydrothermal treatments of the residual biomass of the coffee crop, obtaining an average of 9.11 mg/g of furfural per gram of biomass.