Selective extraction and conversion of lignin in actual biomass to monophenols: A review

Mechanistic understanding of salt-assisted autocatalytic hydrolysis of cellulose

“…1,2 As a renewable and widespread resource, lignocellulosic biomass is a promising candidate and avoids competition with food supply. [3][4][5] Cellulose is the largest component in lignocellulosic biomass and the most abundant polymer in nature, making it a great prospect for the production of biofuels and bio-based chemicals. 6,7 The high degree of cellulose crystallinity is unfavourable for use with solvents and catalysts, and poor heat transfer character of the solid cellulose also limits its application.…”

Oxidized Lignin Depolymerization using Formate Ionic Liquid as Catalyst and Solvent

“…Many papers have reported catalytic methods to oxidize β‐ O ‐4 linkages in lignin, making lignin more reactive for further depolymerization …”

“…Selective depolymerization of lignin to produce well‐defined chemicals remains very challenging owing to the complex structure of lignin . Numerous studies focused on lignin depolymerization, have reported lignin catalytic cracking, hydrolysis, reductive depolymerization, and oxidative depolymerization . Lignin oxidation, compared to other methods, showed high selectivity and efficiency of lignin depolymerization to yield specific products .…”

“…The reported products are mainly phenolic with a low molecular weight, which can be potentially used as a source for producing valuable fine chemicals . Various oxidation methods including enzyme‐based oxidation, biomimetic oxidation and metal complex‐catalyzed oxidation have been developed over the last decades . Some of these methods have reported an oxidation mechanism targeting specific β‐ O ‐4 bonds, which are the most abundant linkages in lignin.…”

Lignin Hydrogenolysis: Improving Lignin Disassembly through Formaldehyde Stabilization

“…In contrast, the hydrogenolysis of isolated lignin or direct hydrogenolysis of lignocellulosic biomass employing heterogeneous metal‐based catalysts represents an appealing approach for converting lignin into low‐molecular weight compounds; however, such reductive approaches are not new . Early studies in this area by Hibbert and co‐workers using lignin derived from maple and spruce wood meal in combination with a copper–chromium oxide catalyst showed that lignin could be hydrogenolyzed and hydrogenated to furnish 4‐propylcyclohexanol‐based aliphatic alcohols .…”