Catalytic Dehydration of Biomass-Derived Feedstocks to Obtain 5-Hydroxymethylfurfural and Furfural

Abstract

Biomass-produced furanics, furfural and 5-hydroxymethylfurfural (5-HMF), are considered as vital platform chemicals used in the production of active pharmaceutical ingredients (APIs), commodity goods, and fuels. The primary challenge associated with their production pertains to the high cost involved in scaling up to industrial levels. Consequently, it is essential to explore more cost-effective options that yield efficient end products. In this study, the use of Lewis and Brønsted acids such as HCl and AlCl₃ enhances the isomerization of glucose through catalytic dehydration into 5-HMF. It was observed that employing moderate reaction conditions increased the yield of 5-HMF to 44.94 % and 50.60 % respectively, with changes in HCl concentration and AlCl₃ mass loading. The suitable conditions to achieve the highest yield of 5-HMF were 100 μL of HCl, 0.75 g of AlCl₃, reaction temperature 150 °C, and reaction time 4 h. In the second experiment, corncob was converted into furfural in the presence of 20 % H₂SO₄, in combination with NaCl as a promoter. The optimal conditions under which a yield of 44.77 % was achieved were as follows: 50 mL of 20 % H₂SO₄, reaction temperature 140 °C, 0.5 g of NaCl, 5 g of corncob, and reaction time 160 min. Furthermore, a proposed reaction mechanism was outlined to elucidate the pathway for the production of the aforementioned platform chemicals.