TY - JOUR
T1 - Fractionation of lignocellulosic materials using ionic liquids
T2 - Part 2. Effect of particle size on the mechanisms of fractionation
AU - Leskinen, Timo
AU - King, Alistair W.T.
AU - Kilpeläinen, Ilkka
AU - Argyropoulos, Dimitris S.
PY - 2013/3/20
Y1 - 2013/3/20
N2 - In part 1 of this effort (Ind. Eng. Chem. Res. 2011, 50, 12349-12357), we studied how wood dissolved in ionic liquid (IL) is precipitated into different molecular weight ranges upon the addition of a cosolvent. In this article, we further analyze the chemical compositions of these fractions and elucidate the mechanisms of fractionation. Specifically, we fractionated Norway spruce wood solvated with 1-allyl-3-methylimidazolium chloride ([amim]Cl) and analyzed the resulting fractions by Klason lignin analysis and FT-IR and NMR spectroscopies. We found that separation of the different components can be tuned by the variable dissolution of wood based on particle size, resulting from preparatory milling. It is possible to obtain cellulose-rich material with a relatively low (6.2%) lignin content, from spruce sawdust. This can achieved by extracting the cellulose from the insoluble lignin-carbohydrate complex (LCC) matrix. Extensive milling of wood afforded a soluble LCC matrix, and its precipitation was based on molecular weight and not on chemical composition. Indications of the presence of LCCs in the hemicellulose fraction were obtained by utilizing multidimensional NMR spectroscopy.
AB - In part 1 of this effort (Ind. Eng. Chem. Res. 2011, 50, 12349-12357), we studied how wood dissolved in ionic liquid (IL) is precipitated into different molecular weight ranges upon the addition of a cosolvent. In this article, we further analyze the chemical compositions of these fractions and elucidate the mechanisms of fractionation. Specifically, we fractionated Norway spruce wood solvated with 1-allyl-3-methylimidazolium chloride ([amim]Cl) and analyzed the resulting fractions by Klason lignin analysis and FT-IR and NMR spectroscopies. We found that separation of the different components can be tuned by the variable dissolution of wood based on particle size, resulting from preparatory milling. It is possible to obtain cellulose-rich material with a relatively low (6.2%) lignin content, from spruce sawdust. This can achieved by extracting the cellulose from the insoluble lignin-carbohydrate complex (LCC) matrix. Extensive milling of wood afforded a soluble LCC matrix, and its precipitation was based on molecular weight and not on chemical composition. Indications of the presence of LCCs in the hemicellulose fraction were obtained by utilizing multidimensional NMR spectroscopy.
UR - http://www.scopus.com/inward/record.url?scp=84875458026&partnerID=8YFLogxK
U2 - 10.1021/ie302896n
DO - 10.1021/ie302896n
M3 - Article
AN - SCOPUS:84875458026
SN - 0888-5885
VL - 52
SP - 3958
EP - 3966
JO - Industrial and Engineering Chemistry Research
JF - Industrial and Engineering Chemistry Research
IS - 11
ER -