Understanding lignin treatment in dialkylimidazolium-based ionic liquid–water mixtures. (November 2015)

• Record Type: Journal Article
• Authors: Yan, Bing; Li, Kunlan; Wei, Ligang; Ma, Yingchong; Shao, Guolin; Zhao, Deyang; Wan, Wenying; Song, Lili
• Is Part Of: Bioresource technology. Volume 196(2015)
• Page Start: 509
• Page End: 517
• Publication Date: 2015-11
• Subjects: Ionic liquid -- Water -- Lignin -- Degradation; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2015.08.005
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Lignin treatment in dialkylimidazolium-based IL-water mixtures was investigated. The pH, IL type and IL content influenced the degradation and structure of lignin. Adding water inhibited lignin depolymerization except for ([C4 mim]Cl)70% . Adding water affected the breakdown of inter-unit linkages and S/G ratio in lignin. Abstract: The treatment of enzymatically hydrolyzed lignin (EHL) in dialkylimidazolium-based ionic liquid (IL)–water mixtures (50–100 wt% IL content) was investigated at 150 °C for 3 h. pH, IL type, and IL content were found to greatly influence the degradation of lignin and the structure of regenerated lignin. 1-Butyl-3-methylimidazolium methylsulfonate–water mixtures with low pH facilitated lignin depolymerization but destroyed the regenerated lignin substructure. Regenerated lignin with low molecular weight and narrow polydispersity index (2.2–7.7) was obtained using a 1-butyl-3-methylimidazolium acetate-based system. Water addition inhibited lignin depolymerization at 50–100 wt% IL content, except for 70 wt% 1-butyl-3-methylimidazolium chloride–water mixture. Compared with pure IL treatment, obvious differences were observed in the breakdown of inter-unit linkages and ratio of syringyl to guaiacyl units in regenerated lignin with IL–water treatment.