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This study presents a novel process of wood modification employing humins, i.e. polydisperse furanic macromolecules formed during sugar dehydration. Humin valorization is more and more in the spotlight, thanks to the increased research efforts being placed by industries on biomass valorization. Here, a water soluble liquid fraction of humins was employed to impregnate wood and was polymerized within the wood using heat. This so-called 'humination' process was compared with the more classical furfurylation, which consists of impregnating with furfuryl alcohol (FA), and the polymerization of FA inside the wood. Confocal laser scanning fluorescence microscopy proved that furanic entities contained in the liquid fraction of humins polymerized within the wood cell walls and resulted in fluorescence similar to that seen for furfurylated wood. The humin modified wood showed lower mass increase and identical dimensional stability compared to furfurylated wood after immersion in water. Both treatments resulted in higher hydrophobicity compared to untreated wood. The elastic modulus of humin treated wood, measured by dynamic mechanical analysis (DMA), was similar to that of furfurylated wood for T < 75 °C and slightly higher than untreated wood. Finally, reaction-to-fire properties were investigated. Humin treated wood showed some advantages over furfurylated wood such as longer ignition time, slower heat release rate (−13%) and lower CO formation. This study demonstrates for the first time that humins can be used as an alternative to FA for wood modification to obtain enhanced wood products. [ABSTRACT FROM AUTHOR]

With a growing interest in the concept of a circular economy, the use of lignocellulosic residues, such as lignins and humins, as potential renewable feedstock for biorefining processes looks increasingly promising. Many challenges remain for the sustainable use of humins, starting from the need to provide reference data reflecting actual usable feedstocks of such materials. This paper offers the first study, from this perspective, of the potential environmental fate of those materials and components, all related to furanics, a family of compounds the toxicity of which is still a matter of debate. Conventional ecotoxicity and biodegradability tests required by European regulation on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) for the primary evaluation of environmental hazards were conducted in combination with fish immunomarker tests to study possible long‐term effects on aquatic ecosystems. These first results are promising as humins did not give rise to any immediate ecotoxicological concerns, and hence their use could be considered in environment‐friendly applications. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]