Composition and structure of organosolv lignins from four eucalypt species

Abstract

Lignins were extracted from different species using organosolv process (ethanol/water). Obtained organosolv lignins were characterised by various methods to determine their composition, structure and functional groups with the purpose of evaluating their potential use for obtaining value-added compounds. The purity of organosolv lignins was determined. The total phenols content and the antioxidant power were analysed in order to know the reactivity of lignins. The ratio S/G was determined by nitrobenzene oxidation. In addition, molecular weight distribution, infrared spectroscopy and thermo gravimetrical analysis were carried out in order to determine the physical and chemical properties of organosolv lignins. Obtained organosolv lignins have very high purity and low sugar and inorganic contamination. All organosolv lignins samples have high polydispersity, and lignin from grey ironbark wood had the highest molecular weight average. Among the organosolv lignins, lemon-scented gum showed the highest average value of S/G ratio and the lowest average value of total phenols.

Categorization of tars from fast pyrolysis of pure lignocellulosic compounds at high temperature

“…and carbonyl groups (1700 cm −1 ) [55]. Both lignin samples were characterized as guaiacyl-syringyl GS type, confirming previous results of Labidi et al [56]. Moreover, the whole C=O range between 1800-1633 cm −1 is intense.…”

Chemical and Fuel Properties of Forestry Wastes From Pine Plantations

“…Regarding the total sum of compounds determined via wet, the properties obtained in the present study are inside the 79-95% range reported in literature by Garcia et al (2014) and Santos et al (2014), who evaluated several lignocellulosic materials, such as woods, barks, stalks, and etc. Therefore, the whole results suggested that to apply classification plans in order to separate each forestry waste leftover of processing wood logs units can affects in a positive way their performance as solid fuels, leading to enhanced thermal energy yields.…”

Fenton Reaction-Oxidized Bamboo Lignin Surface and Structural Modification to Reduce Nonproductive Cellulase Binding and Improve Enzyme Digestion of Cellulose

“…Noncondensed units in lignin moieties, such as guaiacyl, syringyl, and p-hydroxyphenyl, are easily degraded into corresponding phenolic aldehydes and phenolic acids, which helped to analyze the constitutive monomeric composition and the condensation degree of lignin. ,, The alkaline nitrobenzene oxidation (NBO) was commonly used to measure the 4-O-alkylated (α-O-4 and β-O-4) lignin substructures. So, the content and structure of lignin monomers could be analyzed accurately by the combination of a noxidation degraded method and NMR technologies.…”