Plywood is widely used in construction, such as for flooring and interior walls, as well as in the manufacture of household items such as furniture and cabinets. Such items are made of wood veneers that are bonded together with adhesives such as urea–formaldehyde and phenol–formaldehyde resins ^1,2 . Researchers in academia and industry have long aimed to synthesize lignin–phenol–formaldehyde resin adhesives using biomass-derived lignin, a phenolic polymer that can be used to substitute the petroleum-derived phenol ^3–6 . However, lignin–phenol–formaldehyde resin adhesives are less attractive to plywood manufacturers than urea–formaldehyde and phenol–formaldehyde resins owing to their appearance and cost. Here we report a simple and practical strategy for preparing lignin-based wood adhesives from lignocellulosic biomass. Our strategy involves separation of uncondensed or slightly condensed lignins from biomass followed by direct application of a suspension of the lignin and water as an adhesive on wood veneers. Plywood products with superior performances could be prepared with such lignin adhesives at a wide range of hot-pressing temperatures, enabling the use of these adhesives as promising alternatives to traditional wood adhesives in different market segments. Mechanistic studies indicate that the adhesion mechanism of such lignin adhesives may involve softening of lignin by water, filling of vessels with softened lignin and crosslinking of lignins in adhesives with those in the cell wall.

Increasing efforts have been devoted to developing biobased and biodegradable plastics and composites from lignocellulosic biomass. Current bioplastic production entails multiple challenging steps including monomer production from biomass as well as polymer synthesis and modification. Here, we report a practical recombination strategy to transform agricultural residues into moldable cellulose-reinforced lignin (CRL) composites. The strategy involves deconstruction of biomass particles followed by thermo-compression molding of cellulose fibers and lignin mixtures. The resulting CRL composites demonstrated excellent mechanical and thermal properties as well as water, abrasive, and flame resistance. Mechanistic studies reveal that small particle size, removal of water-soluble fractions, as well as reservation of lignin and its cross-linking reactivity have considerably positive effects on preparation of high-quality composite items. These insights offer a versatile strategy for transforming various types of low-grade biomass, such as corn stover, into eco-friendly and potentially biodegradable or compostable composites that can serve as sustainable alternatives to traditional duroplast materials.

Ethanol has been widely used as a clean fuel, solvent, and hydrogen carrier. Currently, ethanol is generally produced through fermentation of starch- and sugarcane-derived sugars (e.g., glucose and sucrose) or ethylene hydration. Its production from abundant and inexpensive lignocellulosic biomass would facilitate the development of green and sustainable society. Biomass-derived carbohydrates and syngas can serve as important feedstocks for ethanol synthesis via biological and chemical pathways. Nevertheless, the biological pathway for producing ethanol through biomass-derived glucose fermentation has the disadvantages of long production period and carbon loss. These issues can be effectively mitigated by chemocatalytic methods, which can readily convert biomass to ethanol in high yields and high atomic efficiency. In this article, we review the recent advances in chemocatalytic conversion of lignocellulosic biomass to ethanol, with a focus on analyzing the mechanism of chemocatalytic pathways and discussing the issues related to these methods. We hope this mini-review can provide new insights into the development of direct ethanol synthesis from renewable lignocellulosic biomass.