Sustainable catalytic valorization of fructose-derived HMF to 2,5-bis(hydroxymethyl)furan and 2,5-bis(hydroxymethyl)tetrahydrofuran

Conversion of biomass into valuable chemicals is a highly sought process. 5-hydroxymethyl-2-furaldehyde (HMF) plays a key role in biorefinery, being employed for the sustainable production of fuels and chemicals. In particular, the highly active and selective hydrogenation of HMF to 2,5-bis(hydroxymethyl)furan (BHMF) and 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF) has drawn much attention for their broad applications. In this research, the hydrogenation in aqueous solution of HMF to BHMF and BHMTHF in autoclave was studied with commercial Pt/C, Ru/C and Pd/C catalysts and the influence of many reaction parameters was optimized. Ru/C resulted the most promising system, allowing a high selective yield towards each of the two monomers, depending on the reaction conditions. Hydrogenation studies on biomass-derived HMF to BHMF and BHMTHF in the presence of Ru/C were also performed without isolation of the intermediate HMF, paving the way for the reaction directly from biomass

Hydrogenation of 5-hydroxymethylfurfural to diols: comparison of batch and flow reactors

Nowadays, the dwindling supplies of worldwide fossil resources and the growing of environmental pollution make the production of chemicals and fuels from renewable resources a key topic of the industrial chemistry. Under this perspective, 5-hydroxymethylfurfural (HMF) is considered as one of the top 12 bio-based compounds: it can be obtained from the dehydration of biomass-derived sugars and its reactive structure makes it a very important platform-chemical, being precursor of fuels, monomers and other valuable products. In this work, the selective hydrogenation of HMF to two diols, 2,5-bis(hydroxymethyl)furan (BHMF) and 2,5-(hydroxymethyl)tetrahydrofuran (BHMTHF) was investigated and optimized both in batch and flow reactors

Insight into the hydrogenation of pure and crude HMF to furan diols using Ru/C as catalyst

5-hydroxymethylfurfural (HMF) is one of the most important renewable platform-chemicals, a very valuable precursor for the synthesis of bio-fuels and bio-products. In this work, the hydrogenation of HMF to two furan diols, 2,5-bis(hydroxymethyl)furan (BHMF) and 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF), both promising renewable monomers, was investigated. Three commercial catalysts, Ru/C, Pd/C and Pt/C, were tested in the hydrogenation of aqueous HMF solutions (2–3 wt%), using a metal loading of 1 wt% respect to HMF content. By appropriate tuning of the process conditions, either BHMF or BHMTHF were obtained in good yields, and Ru/C resulted the best catalyst for this purpose, allowing us to obtain BHMF or BHMTHF yields up to 93.0 and 95.3 mol%, respectively. This catalyst was also tested for in the hydrogenation of a crude HMF-rich hydrolyzate, obtained by one-pot the dehydration of fructose. The influence of each component of this hydrolyzate on the hydrogenation efficiency was investigated, including unconverted fructose, rehydration acids and humins, in order to improve the yields towards each furan diol. Moreover, ICP-OES and TEM analysis showed that the catalyst was not subjected to important leaching and sintering phenomena, as further confirmed by catalyst recycling study