Structural characterization of sugarcane lignins extracted from different protic ionic liquid pretreatments

RENEWABLE ENERGY

卷:161

Article

Pin, Thaynara C.^1,2  Nascimento, Viviane M.^1,3  Costa, Aline C.¹  Pu, Yunqiao⁴  Ragauskas, Arthur J.^2,4,5  Rabelo, Sarita C.⁶ 

[1] Univ Estadual Campinas, Chem Engn Fac, UNICAMP, Av Albert Einstein, BR-13083852 Campinas, SP, Brazil

[2] Univ Tennessee, Dept Chem & Biomol Engn, Middle Dr, Knoxville, TN 37916 USA

[3] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Biorenewables Natl Lab LNBR, BR-13083970 Campinas, SP, Brazil

[4] Oak Ridge Natl Lab ORNL, Biosci Div, Joint Inst Biol Sci, Bethel Valley Rd, Oak Ridge, TN 37831 USA

[5] Univ Tennessee, Ctr Renewable Carbon, Inst Agr, Dept Forestry Wildlife & Fisheries, Knoxville, TN 37996 USA

[6] Sao Paulo State Univ UNESP, Coll Agr Sci, Dept Bioproc & Biotechnol, Av Univ, BR-18610034 Botucatu, SP, Brazil

关键词: Sugarcane bagasse;    Ionic liquid;    Lignin characterization;    Chemical features;    Radar classification;    Biorefinery;   

DOI  :  10.1016/j.renene.2020.07.078

来源: Elsevier

【 摘 要 】

Previous studies based on protic ionic liquids have shown them to be effective for extracting lignins from biomass. Moreover, ILs synthesized with amine cations can promote the insertion of nitrogen into lignin, favoring its valorization for industrial applications. In this study, lignins extracted from sugarcane bagasse by eight different PILs were analyzed. Several techniques of characterization were employed (2D HSQC NMR, 31P NMR, GPC, Py-GC/MS, TGA, FTIR, and elemental analysis), seeking a deeper understanding of lignin structure post-PILS treatment. In particular, lignin obtained with acetate and lactate anions with monoethanolamonium cations showed similar structural compositions. Lignins obtained from ethylenediamonium cation combined anions acetate and lactate exhibited relatively higher molecular weights compared to the other lignins studied. The elemental analysis of these lignins further revealed the presence of nitrogen in their structures, suggesting that amination occurred. In this work we used PILs not yet reported in the literature for this purpose, and consequently obtained lignins with specific structures. Overall, our results demonstrated that depending on the PILs used, lignins with distinct properties could be obtained which might be used for value-added applications. This work covered new advances in elucidation of lignin chemical structure and opened a new path for lignin valorization. (C) 2020 Elsevier Ltd. All rights reserved.

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