Structural Characteristics-Reactivity Relationships for Catalytic Depolymerization of Lignin into Aromatic Compounds: A Review.
Int J Mol Sci 2023;
24:ijms24098330. [PMID:
37176036 PMCID:
PMC10179062 DOI:
10.3390/ijms24098330]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 04/30/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
Developing renewable biomass resources is an urgent task to reduce climate change. Lignin, the only renewable aromatic feedstock present in nature, has attracted considerable global interest in its transformation and utilization. However, the complexity of lignin's structure, uncertain linkages, stability of side chain connection, and inevitable recondensation of reaction fragments make lignin depolymerization into biofuels or platform chemicals a daunting challenge. Therefore, understanding the structural characteristics and reactivity relationships is crucial for achieving high-value utilization of lignin. In this review, we summarize the key achievements in the field of lignin conversion with a focus on the effects of the β-O-4 content, S/G ratio, lignin sources, and an "ideal" lignin-catechyl lignin. We discuss how these characteristics influence the formation of lignin monomer products and provide an outlook on the future direction of lignin depolymerization.
Collapse