Catalytic Dehydration of Fructose to 5-Hydroxymethylfurfural (HMF) in Low-Boiling Solvent Hexafluoroisopropanol (HFIP)

Abstract

A mixture of hexafluoroisopropanol (HFIP) and water was used as a new and unknown monophasic reaction solvent for fructose dehydration in order to produce HMF. HFIP is a low-boiling fluorous alcohol (b.p. 58 °C). Hence, HFIP can be recovered cost efficiently by distillation. Different ion-exchange resins were screened for the HFIP/water system in batch experiments. The best results were obtained for acidic macroporous ion-exchange resins, and high HMF yields up to 70% were achieved. The effects of various reaction conditions like initial fructose concentration, catalyst concentration, water content in HFIP, temperature and influence of the catalyst particle size were evaluated. Up to 76% HMF yield was attained at optimized reaction conditions for high initial fructose concentration of 0.5 M (90 g/L). The ion-exchange resin can simply be recovered by filtration and reused several times. This reaction system with HFIP/water as solvent and the ion-exchange resin Lewatit K2420 as catalyst shows excellent performance for HMF synthesis.

Spent Mango Cellulose-Supported N-Heterocyclic Carbene-Iron(III) Catalyst for Fructose to HMF Dehydration

“…Thus, it is fair to conclude that no appreciable increase in yield occurs after 20 min for Amberlyst-15. The observed decline in HMF selectivity for Amberlyst-15 at a 6 h reaction time is also attributed to HMF condensation side reactions that produces humins, which is more likely to occur at longer reaction times …”

“…The observed decline in HMF selectivity for Amberlyst-15 at a 6 h reaction time is also attributed to HMF condensation side reactions that produces humins, which is more likely to occur at longer reaction times. 45 The behavior of Montmorillonite K-10 (Figure 3c) shows HMF formation at t = 30 min and longer, with an almost linear increment in HMF yield. The ZSM-5 catalyst attains a good yield at t = 6 h but no significant yield up to t = 3 h.…”

Hydrothermal Conversion of Spent Sugar Beets into High-Value Platform Molecules

“…At 200 °C and 0 h reaction time, the highest amount of HMF was obtained; however, the increase of the reaction time to 30 min led to a decrease in the HMF content and an increase in levulinic acid concentration. This effect can be explained by the fact that, under acidic conditions, HMF can be rehydrated to form levulinic and formic acids in aqueous media [ 65 ]. Furthermore, self-condensation of HMF and condensation with other compounds leads to the formation of polymeric substances called humins.…”

Directional synthesis of furfural compounds from holocellulose catalyzed by sulfamic acid

“…So far, the preparation of 5-HMF and FUR from biomass resource is mainly focused on the hydrolysis of saccharides such as glucose, fructose, xylose and xylan derived from cellulose and hemicellulose, in which inorganic strong acid (Román- Leshkov et al 2006;Weingarten et al 2010), acidic ion exchange resin (Tschirner et al 2018) and sulfonic functionalized supported catalyst (Whitaker et al 2020;Dias et al 2006) are generally employed as catalysts. Both homogeneous and heterogeneous catalysts display excellent performance in the conversion of monosaccharides to furfural compounds.…”