Zeolite-catalyzed dehydration of fructose to 5-HMF in glycerol solvent: experimental study and kinetic modeling

Abstract

The selective dehydration of fructose to 5-hydroxymethylfurfural (5-HMF) is a critical step in biomass valorization, yet achieving high efficiency and stability remains challenging. In this study, a novel method for the preparation of 5-HMF by dehydration of fructose using zeolite catalyst in glycerol as solvent was explored，investigating the interplay between catalyst structure and reaction kinetics. Renewable, non-toxic and biodegradable glycerol replaced traditional toxic organic solvents to break through the bottleneck of green chemistry. Meanwhile, the high boiling point of glycerol expands the temperature range of the reaction and promotes the efficient dissolution and homogeneous reaction of fructose at high temperatures. Compared with the high temperature instability of aqueous systems and the high cost of ionic liquids, this system is a multi-dimensional breakthrough in terms of environmental protection, reaction efficiency and process economy, providing a new strategy for biomass resource conversion that is both sustainable and practical. A systematic evaluation of H-ZSM-5, H-beta-25, Ammonium-Y, Ag-exchange, and MCM-41 reveals that H-beta-25 exhibits the optimal balance of surface area, microporous volume, leading to better fructose conversion and 5-HMF selectivity than other catalysts. The fitting of the experimental data of the fructose dehydration reaction based on a first-order kinetic model combined with the Arrhenius equation provides an accurate description of the reaction kinetics and validates the study of the reaction mechanism. The study of the kinetic model is helpful in suggesting experimental optimization of fructose dehydration. Additionally, the study highlights the dual function of glycerol: while its high viscosity limits mass transfer at lower temperatures, its thermal stability and hydrogen bonding mitigate side reactions, facilitating selective conversion. These findings underscore the importance of optimizing catalyst properties and reaction conditions to improve 5-HMF yield and stability. This research contributes to the advancement of sustainable bio-based chemical production by optimizing catalyst-solvent interactions for efficient fructose dehydration.

Date of Award	15 Aug 2025
Original language	English
Awarding Institution	University of Nottingham
Supervisor	Kam Loon Fow (Supervisor), Lionel O'Young (Supervisor) & Zeping Wang (Supervisor)