Understanding lignin treatment in dialkylimidazolium-based ionic liquid-water mixtures.
The treatment of enzymatically hydrolyzed lignin (EHL) in dialkylimidazolium-based ionic liquid (IL)-water mixtures (50-100wt% IL content) was investigated at 150°C for 3h. 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 50-100wt% IL content, except for 70wt% 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.
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, 116034 Dalian, China.
Bing
B
Yan
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, 116034 Dalian, China.
Kunlan
K
Li
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, 116034 Dalian, China. Electronic address: weilg@dlpu.edu.cn.
Ligang
L
Wei
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, 116034 Dalian, China.
Yingchong
Y
Ma
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, 116034 Dalian, China.
Guolin
G
Shao
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, 116034 Dalian, China.
Deyang
D
Zhao
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, 116034 Dalian, China.
Wenying
W
Wan
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, 116034 Dalian, China.
Lili
L
Song
D006868:Hydrolysis; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D008031:Lignin / Q000737:chemistry*; D058105:Polymerization; D014867:Water
C525963:1-butyl-3-methylimidazolium; D007093:Imidazoles; D052578:Ionic Liquids; D014867:Water; D008031:Lignin
Degradation; Ionic liquid; Lignin; Water