Novel Challenges on the Catalytic Synthesis of 5-Hydroxymethylfurfural (HMF) from Real Feedstocks

Abstract

The depletion of fossil resources makes the transition towards renewable ones more urgent. For this purpose, the synthesis of strategic platform-chemicals, such as 5-hydroxymethylfurfural (HMF), represents a fundamental challenge for the development of a feasible bio-refinery. HMF perfectly deals with this necessity, because it can be obtained from the hexose fraction of biomass. Thanks to its high reactivity, it can be exploited for the synthesis of renewable monomers, solvents, and bio-fuels. Sustainable HMF synthesis requires the use of waste biomasses, rather than model compounds such as monosaccharides or polysaccharides, making its production more economically advantageous from an industrial perspective. However, the production of HMF from real feedstocks generally suffers from scarce selectivity, due to their complex chemical composition and HMF instability. On this basis, different strategies have been adopted to maximize the HMF yield. Under this perspective, the properties of the catalytic system, as well as the choice of a suitable solvent and the addition of an eventual pretreatment of the biomass, represent key aspects of the optimization of HMF synthesis. On this basis, the present review summarizes and critically discusses the most recent and attractive strategies for HMF production from real feedstocks, focusing on the smartest catalytic systems and the overall sustainability of the adopted reaction conditions.

Microwave-Assisted Production of 5-Hydroxymethylfurfural from Fructose Using Sulfamic Acid as a Green Catalyst

“…The main approaches to produce 5-HMF typically involve the thermal or acid-catalyzed dehydration of C6-sugars, such as the biomass derivatives fructose and glucose. Among these sugars, fructose is particularly well-suited due to its predominant furanose form (5-member monosaccharide ring), which is easily dehydrated compared to the pyranose form (6-member monosaccharide ring) [4].…”

Beyond 2,5-furandicarboxylic acid: status quo, environmental assessment, and blind spots of furanic monomers for bio-based polymers

“…HMF is commonly produced through acid-catalysed triple dehydration of hexoses, such as D-glucose and D-fructose (Scheme 1), however it has also been synthesized from oligosaccharides such as, starch, cellulose, or inulin, or through the one-pot conversion of complex lignocellulosic, amylaceous, or free sugar rich raw materials. 27,28 Numerous homogeneous or heterogeneous catalytic systems, combined with specific choices of solvents (single phase or biphasic media), have been systematically explored to…”

Challenges and Opportunities in the Catalytic Synthesis of Diphenolic Acid and Evaluation of Its Application Potential

“…Ionic liquids are well-known, robust, and designable organic salts typically composed of large cations and small anions that can find applications as solvents and catalysts for carrying out the syntheses of several bio-based compounds [ 37 ]. In the field of DPA synthesis, acid ionic liquids have been proposed for the condensation reaction between LA and phenol.…”