Lignin — a promising biomass resource

Abstract

Lignin, the second most abundant component in plants, is a class of complex aromatic polymer. Industrial lignin is a major byproduct of pulp and paper production and biorefineries, with more than 50 megatons generated annually. However, more than 98% of industrial lignin is either burned as fuel or discharged as wastewater, causing serious environmental pollution. From a sustainable feedstock perspective, finding additional high-volume and high-value applications for lignin is an extremely important and long-term pursued objective. Thus, lignin resources deserve to be further exploited as biorenewable raw materials for energy-saving and lowcarbon polymer production. Inspired by the natural three-dimensional structure, excellent ultraviolet-blocking and antioxidant properties of lignins, the authors have focused their research on lignin-based biorenewable resources. This review summarizes research achievements of the recent decade. Progress has been made in several aspects, such as nonionic and amphoteric lignin-based surfactants, lignin-based functional materials, lignin-based photoelectric materials, lignin-based resins and polymer composites, and catalytic depolymerization of lignin.