Synthesis of 5-hydroxymethylfurfural (5-HMF) from fructose over cation exchange resin in a continuous flow reactor

Continuous Flow Upgrading of Selected C2–C6Platform Chemicals Derived from Biomass

“…A common strategy for maximizing the yield involves biphasic solvent mixtures (Figure ). ,,,− Sugars are dehydrated in a polar solvent (typically water), and once HMF is formed, it is continuously extracted in a less polar cosolvent (typically methyl isobutyl ketone, MIBK). This strategy prevents degradation reactions of HMF, such as the acid-catalyzed rehydration into levulinic and formic acids (Scheme ), or the combination of oligomerization and degradation toward humins.…”

“…Therefore, researchers alternatively studied continuous flow processes involving packed-bed reactors loaded with solid heterogeneous acid catalysts (Figure ). Catalysts described included resins, ,− metal oxides, ,,− or metal oxides functionalized with organic sulfonic acid moieties. , Although processes catalyzed by homogeneous mineral acids almost exclusively relied on biphasic solvent conditions (Table ), the literature describing the use of heterogeneous catalysts mostly relies on homogeneous reaction media. The sugar substrate typically requires polar solvents in the feedstock solution for solubility reasons, but water tends to promote a side-reaction toward levulinic acid (Scheme ).…”

“…721,728,729,731 Carniti studied the dehydration of aqueous fructose solutions over niobium oxide based catalysts 733,734. Moderate conversions and low yields were obtained (Table30, entries 11−12).…”

Production of 2,5-furandicarboxylic acid via oxidation of 5-hydroxymethylfurfural over Pt/C in a continuous packed bed reactor

“… 16 Sonsiam et al drastically shortened the reaction time (residence time) for the dehydration of fructose to 5-HMF in a continuous flow reactor compared to the batch reactor. 17 …”

Microwave-Assisted Efficient Fructose–HMF Conversion in Water over Sulfonated Carbon Microsphere Catalyst

“…Generally, the synthesis of HMF from biomass strongly depends on homogeneous catalyst usage. However, the homogeneous catalyst is the most effective method to produce HMF by dehydration/hydrolysis from carbohydrate derivatives that should be replaced with green catalysts. − Besides, several reports have pointed out that it might be difficult to recover homogeneous catalysts, including inorganic acids and salts, resulting in a large amount of waste liquid. − According to green chemical principles, environmentally friendly solvents and catalysts should also be used in relevant processes. Therefore, to improve the catalytic efficiency of the catalyst for converting fructose into HMF and simplify the separation and recovery process of the catalyst, the development of a cost-effective and environmentally friendly conversion method has attracted considerable attention in the past. , Based on that, we have developed sulfonated carbon solid acid catalysts by a simple reflux method as a one-pot reaction in this work to produce HMF from fructose.…”