PRODUCTION OF 5-HYDROXYMETHYLFURFURAL FROM CELLULOSE RICH LIGNOCELLULOSIC BIOMASS USING CATALYTIC ROUTE

Abstract

5-Hydroxymethylfurfural (5-HmF) is considered the most valuable among the platform compounds derived from lignocellulosic biomass. The current research focuses on the chemosynthesis of 5-HmF from different cellulose-rich low-cost biomass through a one-pot process with a high yield and stability. Avicell PH-101 was considered representative of cellulose. Initial screening of co-solvent and water demonstrated the suitability of tetrahydrofuran as an efficient organic co-solvent. At the same time, acetone helps form levulinic acid (10.00 ± 0.1 %) due to further degradation of 5-HmF (0.67 ± 0.07%). A synergistic role of different Lewis acid and sulphuric acid as Brønsted acid catalysts were critically investigated on Avicell PH-101. Further, lewis acid catalyst screening with various metal chlorides was performed, and BaCl2 and sulphuric acid as a Bronsted acid catalyst yielded 31.58 ± 0.62% 5-HmF with low levulinic acid of 3.25 ± 0.39% compared to other di-chlorides and tri-chlorides. The crucial role of different reaction parameters was screened using the Placket Burman design matrix, followed by Response Surface Methodology to optimize time and substrate to surface ratio. The optimized reaction conditions as predicted using numerical optimization were 0.009 substrates to solvent ratio and a reaction time of 95 minutes at a constant temperature of 160℃. The optimum 5-HmF and LA yields were 46.36 ± 1.83% and 8.02 ± 1.43%, respectively. The optimized reaction conditions were further considered with different lignocellulosic biomasses such as sugarcane bagasse, wheat straw, spent coffee ground, wheat bran, orange peel, finger millet husk, and coffee bean husk, and fruitful results were obtained. The scope of the process was further extended to dignified and delignified-acid hydrolyzed sugarcane bagasse residue, and the highest 5-HmF yield obtained in delignified-acid hydrolyzed sugarcane bagasse residue was 14.58%, with 7.92% furfural along with 3.62% levulinic acid. This work demonstrates the potential of chemo-transformation of complex renewable lignocellulosic biomass to furan compounds and their derivatives.