Sustainable Routes for the Depolymerization of Lignocellulosic Biomass

Abstract

Lignocellulosic biomass is the world largest renewable resource used as a raw material to produce high‐value‐added chemicals, such as biofuels and other biomaterials. However, the complex chemical structures of its main constituents, named cellulose, hemicelluloses, and lignin, pose a challenge to the breakdown of these biopolymers into smaller units. In this scenario, sustainable methods for the depolymerization of lignocellulosic biomass aim to chemically break these macromolecules into simple monomers and dimers, while minimizing the use of hazardous chemicals and energy‐intensive processes. Different depolymerization strategies have been proposed, including enzymatic, electrochemical, acid‐catalyzed, and solvent‐based methods. Nevertheless, the development and improvement of sustainable approaches toward depolymerization technologies is still ongoing, and there is still room for further research to optimize the efficiency, cost‐effectiveness, and scalability of the processes. While the successful depolymerization of biomass may significantly contribute to the transition to a more sustainable and environmentally friendly economy, this article outlines the most recent developments focusing on the particularities of these processes, including biological, electrochemical, thermal, and chemical methods.

Organic Chemicals from Wood: Selective Depolymerization and Dearomatization of Lignin via Aqueous Electrocatalysis

“…[2,5] Nevertheless, because of its complex and highly aromatic structure, comprised of phenolic and non-phenolic units linked through various ether and carbon-carbon bonds, the efficient and selective breakage of this macromolecule is rather challenging. [6,7] To enhance value-added processes for lignin conversion, researchers have explored several depolymerization techniques aimed at producing functionalized aromatic compounds at ambient temperature with high yields. [3,[6][7][8] In this pursuit, electrocatalysis (EC) has emerged as a noteworthy approach due to its alignment with sustainable principles.…”

“…[6,7] To enhance value-added processes for lignin conversion, researchers have explored several depolymerization techniques aimed at producing functionalized aromatic compounds at ambient temperature with high yields. [3,[6][7][8] In this pursuit, electrocatalysis (EC) has emerged as a noteworthy approach due to its alignment with sustainable principles. [9][10][11] Additionally, EC enables precise control of cell potential, thereby improving catalyst selectivity and activity, while allowing the adoption of mild reaction conditions, including room temperature and environmentally friendly solvents.…”