Solvent effects on the molecular structure of isolated lignins of Eucalyptus nitens wood and oxidative depolymerization to phenolic chemicals

Hemicellulose pyrolysis: mechanism and kinetics of functionalized xylopyranose

“…Muñiz and collaborators 110 developed a methodology to predict the performance of carbon-based electrode materials for energy storage by assessing the reaction mechanism of various lignocellulosic components resulting from the pyrolysis of Agave angustifolia leaves. Yáñez et al 111 studied the influence of a solvent-water mixture used to extract lignin (from Eucalyptus nitens ) on its structural features and content of functional groups. Very recently, Xia and co-workers 112 prepared graft-modified fibbers from starch polymers as alternative adhesives.…”

Sustainable lignin modifications and processing methods: green chemistry as the way forward

“…255 Generally, oxidative depolymerization is performed in aqueous alkaline solutions to improve the depolymerization degree by improving the solubility. 250,251,257 However, Ren et al reviewed the oxidative depolymerization and concluded that besides extreme conditions resulting in the ring-opening of aromatics and yielding small fatty acids, the use of alkaline media yields aromatic monomers, while non-caustic media yield small fatty acids. 258 Rozas et al investigated the effect of using different solvent/water systems in the delignification process of Eucalyptus nitens wood on the subsequent alkaline oxidative depolymerization (160 °C, 2 h) with O 2 (7 bar).…”

“…In all the experiments, primarily aldehydes were present with a higher content of syringaldehyde over vanillin due to the predominance of S-units over G-units and the subsequent carboxylic acids by oxidation of the aldehydes. 257 Kumar et al investigated the addition of acidic (H-ZSM-5) and basic (MgO) catalysts in the oxidative depolymerization (160 °C, 1 h) of rice straw AL in MeOH ( problematic solvent according to Table 3) with O 2 and H 2 O 2 . The yields of bio-oil obtained were 50 wt% with H-ZSM-5 under an N 2 atmosphere with 1 mL H 2 O 2 and 47 wt% with H-ZSM-5 and O 2 .…”

Emission of Volatile Organic Compounds from the Heat Treatment of Afrormosia and Newtonia Wood: Effects of Air and Palm Oil Heat Media

“…The alcohols emitted during the heat treatment of Afrormosia are mostly phenolic in nature and increased with the rising of temperature (Table 2). These compounds can exist in the wood in small quantities as extractives [25]; however, they can also be produced by the oxidation of lignin [41], which occurs gradually with an increase in temperature [5]. In other words, for low temperatures, the oxidation of lignin is carried out weakly, but it increases with the elevation of the temperature, which is manifested by the small emissions of alcohols of phenolic nature that, however, increase with the temperature.…”