Synthesis of Furfural from Xylose Using Carbon-Based Bifunctional Solid Acid Catalyst in the Biphasic System

Abstract

The objective of this research was to convert xylose into furfural using flax straw-based bifunctional solid acid catalyst. The catalyst was synthesized by impregnation-carbonization and sulfonation processes. The characterization of biochar, Al-biochar, and sulfonated Al-biochar catalyst were carried out by using Brunauer–EmmetTeller (BET), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results showed that the surface area, total acid density, and SO3H density of sulfonated Al-biochar catalyst were 516.03 m2/g, 4.767 ± 0.23 mmol/g and 1.033 ± 0.1 mmol/g, respectively. The result of FTIR indicated that the presence of the different functional groups such as the phenolic group (-OH), carboxylic group (-COOH), sulfoxide group (-SO3H), and Al-O-Al on the surface of the prepared catalyst. The catalytic performance of the synthesized catalyst was evaluated in a biphasic system of water and 2-methyl tetra hydro furan. The effects of dehydration reaction parameters (reaction temperature, reaction time, and catalyst loading) on the formation of furfural were also studied. The maximum furfural formation was obtained at 180°C, 2 hr, and 0.2 gm of catalyst loading. Under this condition, the yield of furfural was around 64.7%, with a selectivity of 88.0%. The study demonstrated the effectiveness of the catalyst in the transformation of xylose into furfural.