Reductive Catalytic Fractionation: From Waste Wood to Functional Phenolic Oligomers for Attractive, Value-Added Applications
Gil Van den Bossche, Thijs Vangeel, Korneel Van Aelst, Wouter Arts, Laura Trullemans, Kranti Navaré, Sander Van den Bosch, Karel Van Acker, Bert F. Sels
Abstract
Reductive catalytic fractionation (RCF) is proven to be a promising biorefinery strategy for the valorization of lignocellulosic biomass. A large part of past and present RCF research has been directed at the conversion of freshly harvested biomass instead of recycled lignocellulose fractions. Moreover, the focus of RCF research often lies in obtaining high phenolic monomer yields, while the product mixture also consists of dimers and oligomers. However, this paradigm is shifting. Following the cascading principle, the use of sustainable and inexpensive post-consumer wood (PCW) forms an alluring alternative to freshly harvested wood. In parallel, the applicability of the dimers and oligomers in the phenolic product mixture is receiving increased attention, which was previously overshadowed by the monomer fraction. This chapter discusses the potential of post-consumer wood (PCW) as a feedstock for RCF biorefining, aiming to produce functional, ‘intermediate molecular weight’ phenolics. The first part discusses the framework of cascading wood use in the EU, with an emphasis on the collection of PCW and its sorting based on (in)organic contaminants. The second part reviews biorefining strategies that specifically target PCW. The third part highlights RCF as potential biorefinery strategy, while critically discussing catalyst deactivation as a major challenge. The last part outlines the possible applications of the targeted phenolic oligomers, providing value to this intermediate molecular weight product fraction.