Hydroxymethylfurfural (HMF) – A valuable, bio-derived platform chemical

Hydroxymethylfurfural (HMF) is a promising bio-derived platform chemical for value-added chemicals. For a sustainable development, the use of renewable resources must be enhanced and more sustainable ways for chemical production must come into focus. Lately, the realization of industrial scale HMF production has gained much more attention.

Carbohydrate conversion to HMF

HMF combines the structure of furfural and furfuryl alcohol; it has a hydroxyl and aldehyde group as well as a furan ring. The acid catalyzed dehydration of monosaccharides, e.g. fructose or glucose, results in the formation of HMF. Generally, the HMF formation is described as the removal of three water molecules from the sugar molecule.

Figure: Dehydratisation to HMF and rehydration of HMF to side-products levulinic acid and formic acid

Two different mechanisms, one involving a cyclic and one an acyclic route were proposed for the HMF formation by the scientific community. A definite proof for either of the two mechanistic routes is yet to be found. Several kinetic studies investigates the HMF formation, their contribution is not limited to shedding light on the mechanistic behind the HMF formation, but they also provide valuable insight for the development of optimum reactor configurations and process conditions.

Recent process developments

Recently, the realization of industrial scale HMF production processes has gained much more attention and an increasing number of HMF production methods have been patented in the last couple of years. Several adjustments to existing production methods have been made to improve the chemical and economic efficiency of the HMF production processes. The production methods can roughly be divided in the main research fields: operational aspects (operating mode, reactor design), solvent system (single-phase systems, biphasic systems), catalytic systems (salts, acid ion-exchange resins) as well as feedstock selection and conversion (isomerase enzyme, partial conversion endpoint, producing HMF from by-products).

A first-small scale, commercial production plant using hydrothermal carbonization is operating since 2004. The production of HMF still faces some challenges regarding yield and sustainable and economic process designs.

Challenges in HMF production

The formation of side products, especially of solid condensation products (often referred to as humins) still pose immense problems in the up-scaled HMF production. In addition the separation of HMF from the reaction media and its subsequent purification causes difficulties due to the thermal lability of HMF.

Potential of HMF as value-added platform chemical

HMF is often referred to as promising bio-derived platform chemical, because it has the potential to replace a large range of conventionally produced building blocks. Due to the anticipated enormous market potential, HMF is often called a “sleeping giant”. The HMF derivative, 2, 5-furandicarboxylic acid (FDCA) was listed by the US Departments of Energy as one of the twelve top value-added chemicals in 2004. In addition, HMF derivatives such as 2, 5- (bishydroxymethyl)furan or 2,5-diformylfuran are promising crosslinkers in the resin production.

Check out the publication from Wood K plus & BOKU for more details on the current situation of the challenging scale-up development of hydroxymethylfurfural production.

Find the current full open access publication here. For more information on the potential of HMF and its derivatives in the adhesive production stay tuned for the follow-up blog post.

 

Author: 

DI Catherine Thoma, BSc.

Junior Researcher, Area Wood Materials Technologies

Kompetenzzentrum Holz GmbH, Wood K plus

Co-Authors:

Johannes Konnerth, Wilfried Sailer-Kronlachner, Pia Solt, Thomas Rosenau and Henrikus W.G. van Herwijnen

 

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