TY - JOUR
T1 - Fractionation of Lignin with Decreased Heterogeneity
T2 - Based on a Detailed Characteristics Study of Sequentially Extracted Softwood Kraft Lignin
AU - Liu, Rui
AU - Smeds, Annika
AU - Wang, Luyao
AU - Pranovich, Andrey
AU - Hemming, Jarl
AU - Willför, Stefan
AU - Zhang, Hongbo
AU - Xu, Chunlin
N1 - Funding Information:
R.L. acknowledges the financial support by China Scholarship Council (201908120132) and the Doctoral Programme in Chemical and Process Engineering at Åbo Akademi University (ÅAU), Finland. The Business Finland Project (43674/31/2020) is acknowledged for the research funding to support the current work. This work is also part of activities within the Johan Gadolin Process Chemistry Centre (PCC) at ÅAU.
Funding Information:
This work was supported by the China Scholarship Council (201908120132), the Doctoral Programme in Chemical and Process Engineering at Åbo Akademi University (ÅAU), Finland, and the Business Finland Project (43674/31/2020).
Publisher Copyright:
© 2021 The Authors. Published by American Chemical Society.
PY - 2021/10/18
Y1 - 2021/10/18
N2 - Industrial lignin fractionation is attracting increasing interest due to its enormous potential in the development of high value-added materials. However, the widely reported fractionation approaches are primarily focused on the separation of fractions with a low polydispersity index (PDI). In this study, based on the detailed characteristic examination of carefully sequential-extracted softwood Kraft lignin fractions, a novel method to isolate lignin fraction with decreased heterogeneity (LGF-dh), was established in consideration of impurities, elemental composition, molar mass distribution, carbohydrate content, functional hydroxyl content, and the content of lignin-relevant aromatic units. To characterize the mentioned properties, an elemental analyzer, SEC-MALS, GC-MS, GC-FID, Py/GC-MS, 31P-NMR, and HSQC-NMR were used to compare the differences of the sequential lignin fractions that were obtained by methyl tert-butyl ether (MTBE), ethyl acetate (EtOAc), ethanol (EtOH), methanol (MeOH), acetone, and dioxane. Moreover, a practical and feasible three-step extraction process was proposed to separate the low heterogeneity lignin fraction from industrial lignin according to the different solubilities of each fraction in the green cosolvent system of EtOH/water, MeOH/water, and acetone/water. Overall, this work presented a comprehensive study on the properties of softwood lignin as well as proposed a feasible and convenient method to reduce the heterogeneity of lignin, which would promote its valorization.
AB - Industrial lignin fractionation is attracting increasing interest due to its enormous potential in the development of high value-added materials. However, the widely reported fractionation approaches are primarily focused on the separation of fractions with a low polydispersity index (PDI). In this study, based on the detailed characteristic examination of carefully sequential-extracted softwood Kraft lignin fractions, a novel method to isolate lignin fraction with decreased heterogeneity (LGF-dh), was established in consideration of impurities, elemental composition, molar mass distribution, carbohydrate content, functional hydroxyl content, and the content of lignin-relevant aromatic units. To characterize the mentioned properties, an elemental analyzer, SEC-MALS, GC-MS, GC-FID, Py/GC-MS, 31P-NMR, and HSQC-NMR were used to compare the differences of the sequential lignin fractions that were obtained by methyl tert-butyl ether (MTBE), ethyl acetate (EtOAc), ethanol (EtOH), methanol (MeOH), acetone, and dioxane. Moreover, a practical and feasible three-step extraction process was proposed to separate the low heterogeneity lignin fraction from industrial lignin according to the different solubilities of each fraction in the green cosolvent system of EtOH/water, MeOH/water, and acetone/water. Overall, this work presented a comprehensive study on the properties of softwood lignin as well as proposed a feasible and convenient method to reduce the heterogeneity of lignin, which would promote its valorization.
KW - compositions
KW - lignin fractionation
KW - softwood Kraft lignin
KW - solvent fractionation
KW - structural characteristics
UR - http://www.scopus.com/inward/record.url?scp=85117845212&partnerID=8YFLogxK
U2 - 10.1021/acssuschemeng.1c04725
DO - 10.1021/acssuschemeng.1c04725
M3 - Article
AN - SCOPUS:85117845212
VL - 9
SP - 13862
EP - 13873
JO - ACS Sustainable Chemistry and Engineering
JF - ACS Sustainable Chemistry and Engineering
SN - 2168-0485
IS - 41
ER -