Lignin alkaline oxidation using reversibly-soluble bases

Abstract

Lignin valorization approaches, which are critical to biorefining, often involve depolymerization to aromatic monomers. Alkaline oxidation has long held promise as a lignin depolymerization strategy, but requires high concentrations of...

Oxidative Catalytic Fractionation of Lignocellulose to High-Yield Aromatic Aldehyde Monomers and Pure Cellulose

“…34 Therefore, the removal of hemicellulose from biomass can reduce the consumption of NaOH if the fractionation process has no significant change in the lignin structure. In addition, simply the separation of an alkali, solid base, or temperature-sensitive base (i.e., insoluble at room temperature but soluble at high temperatures) can be used to replace NaOH, 35 and a well-designed catalyst can even avoid the use of alkali. 36 These options are currently under investigation.…”

Scaled Oxidative Flow Electrosynthesis of 3-Alkyladipic Acids from 4-Alkylcyclohexanols

“…For this purpose, the basic reaction medium was extracted three times with tert-butyl methyl ether (each 100 mL), acidified with 4.5 M sulfuric acid to pH 1−2, and extracted four times with ethyl acetate (each 100 mL). After drying over MgSO 4 and subsequent solvent removal, the product mixture was analyzed using 1 H and 13 C inverse-gated NMR against 1,3,5-trimethoxybenzene as an internal standard.…”

“…Moreover, chemical research is aiming to transition from fossil-based resources to regenerative ones. One possible avenue is the use of biogenic feedstocks, such as lignin, which is mostly used for energy purposes in the pulping industry. − It represents the world’s largest aromatic feedstock, does not compete with nutrition purposes, and is renewable. , …”

Heteroatom-doped lignin-derived carbon material: performance and application

“…Abundant O-containing functional groups in lignin, including methoxy, carbonyl, and hydroxyl groups, endow lignin with a complicated structure, 7 and hence, making the most use of lignin has been considered a promising but highly challenging eld. Currently, extensive research studies have been focused on lignin depolymerization, i.e., cleaving C-O/C-C bonds in lignin to obtain value-added aromatic compounds 8 by various strategies, including hydrogenolysis, [9][10][11][12] oxidation, [13][14][15][16] electro/photocatalysis, [17][18][19][20] and constructing lignin-based N-heterocyclic compounds [21][22][23] (e.g., quinoxalines and pyrimidines) to be used as pharmacological agents. The corresponding research progress has been summarized by many researchers.…”