Catalytic conversion of high S-lignin to a sustainable tri-epoxide polymer precursor

Abstract

More than 40 million tons of thermosetting plastics are produced annually and 70% of those are epoxy polymers. The synthesis of bio-based epoxide provides a pathway for making renewable thermoset...

The lignin challenge in catalytic conversion of biomass solids to chemicals and fuels

“…8 compares the efficiency of a lignin-first approach to ones where other extraction methods were first used to separate the lignins from the high-S poplar lignocellulose prior to hydrogenolysis of the extractant to give monomers. 50 In dry, high-S poplar wood, lignin is a 22% (by wt) component, so a 10 g sample of that material contains 2.2 g of intact lignin. The extraction pathways examined included: refluxing with acidic methanol for 14 days (OPL), reacting with acidic formaldehyde in dioxane at 95 °C for 3.5 h (FPL), and extracting by heating in a formic acid/acetic acid mixture (FA/AA) or aqueous hydrochloric or sulfuric acid.…”

“…However, direct RCF of high-S poplar sawdust itself under analogous catalytic conditions gave a significantly higher overall yield of monomers (61% of the initial 22% lignin). 50 Furthermore, direct lignin-first procedure requires shorter overall processing times and less solvent and other reagents, thus is a greener process.…”

“…In an extension of the above study, Liu et al 50 extracted 4-propyl-2,6-dimethoxyphenol (DMPP) from poplar biomass that had been genetically modified to afford high-sinapyl (high-S) lignin. The DMPP was then converted to propyl-pyrogallol (DMPPO) in a reaction catalyzed by calcined Nb 2 O 5 in water.…”

Catalytic Strategies and Mechanism Analysis Orbiting the Center of Critical Intermediates in Lignin Depolymerization

“…High-S lignin in poplar biomass. Adapted from ref with permission. Copyright 2022 The Royal Society of Chemistry 2022.…”

Enhanced lignin depolymerisation to produce butylated hydroxytoluene and 4-propylguaiacol on carbon-nitride supported molybdenum catalysts

“…4 As an important method for lignin valorisation, catalytic conversion of industrial lignin has become preferable for more and more scientific researchers, and it is characterised by both a high catalytic activity and high selectivity. 5,6 To date, the supported noble metal catalysts have been used most frequently in cleaving C-O and C-C linkages of lignin and model compounds. 7,8 However, the usage of precious metal catalysts is usually rather costly, moreover, the considerable catalytic activities lead to the production of by-products, which puts the precious metal catalysts at a steep disadvantage.…”