Valorization of Biomass to Furfural by Chestnut Shell-based Solid Acid in Methyl Isobutyl Ketone-Water-Sodium Chloride System.

Recently, highly efficient production of furfural from available, abundant, inexpensive, and renewable lignocellulosic biomass has gained much attention by using biomass-based heterogeneous catalyst in an effective biphasic system. Using microwave-treated chestnut shell (MC-CNS) as biobased support, biomass-based catalyst (MC-Sn-CNS) was firstly synthesized for catalyzing biomass into furfural. The structure parameters of MC-Sn-CNS were measured by BET, SEM, XRD, and FT-IR. After systematical optimization, furfural yield reached 64.4% from corncob by MC-Sn-CNS (3.6 wt%) at 180 °C for 15 min in methyl isobutyl ketone (MIBK)-water (2:1, v:v) containing 200 mM NaCl. MC-Sn-CNS had high stability, which could be recycled for 7 batches. The yield of furfural from fresh corncob was 44.5-64.4%. The possible catalytic mechanism for synergistic catalysis of biomass to furfural by MC-Sn-CNS was expounded in MIBK-water-NaCl system. The results showed that green solvent (MIBK) and NaCl promoted the production of furfural from CC catalyzed by solid acid (MC-Sn-CNS). This study demonstrated an environmentally friendly strategy for efficiently utilizing corncob into furfural by CNS-based heterogeneous chemocatalyst in a green reaction media. Clearly, this newly synthesized biomass-based MC-Sn-CNS catalyst had potential application in the future.