Abstract:
In this work, a closed-loop strategy for the management and valorization of winery
waste was proposed. The exhausted pomace and grape stalks that are typically obtained from
white wine industries were used as a source of simple sugars, namely, glucose and fructose, and of
lignocellulosic feedstock for the preparation of selective catalysts for the 5-hydroxymethylfurfural
(5-HMF) production from fructose. A novel synthetic procedure was developed for the synthesis
of iron-sulfonated magnetic biochar catalysts (Fe-SMBCs). Fourier transform infrared spectroscopy
(FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX),
BET surface area, porous structure analysis and determination of total amount of acid sites were
performed in order to characterize the physico-chemical properties of the synthesized systems. Then,
these heterogeneous catalysts were successfully tested via the dehydration of simple sugars into
5-HMF by using methyl isobutyl ketone (MIBK) and gamma valerolactone (GVL) as co-solvents.
The optimum 5-HMF yield of 40.9 ± 1.1%mol with a selectivity of 59.8 ± 2.6%mol was achieved by
adopting the following optimized conditions: 0.1 g of catalyst, volume ratio of GVL to H2O = 2 to 1,
403 K, 6 h. In addition, the catalyst was easily recycled using an external magnetic field and used for
at least five reaction cycles without significant loss of catalytic activity.
