TY - JOUR
T1 - Selective extraction of hemicelluloses from spruce using switchable ionic liquids
AU - Anugwom, I.
AU - Mäki-Arvela, P.
AU - Virtanen, P.
AU - Willför, S.
AU - Sjöholm, R.
AU - Mikkola, J.-P.
N1 - Funding Information:
This work is part of the activities at the Åbo Akademi Process Chemistry Centre (ÅA-PCC) within the Finnish Centre of Excellence Program (2000–2011) appointed by the Academy of Finland. Forest Cluster Ltd. and The Finnish Funding Agency for Technology and Innovation (TEKES) are gratefully acknowledged for financial support. In Sweden, the Bio4Energy program is acknowledged.
Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/2/14
Y1 - 2012/2/14
N2 - Switchable ionic liquids (SILs) made from alcohols, either hexanol or butanol, and CO 2 together with an amidine (1,8-diazabicyclo-[5.4.0]- undec-7-ene (DBU)) were investigated as dissolution/fractionation solvents for wood material. Both native spruce (Picea abies), and pre-extracted spruce were treated with either butanol SIL (SIL1) or hexanol SIL (SIL2) for 5 days at 55 °C under normal pressure. The SILs were formed by bubbling CO 2 through an equimolar mixture of either 1-hexanol or 1-butanol and DBU. The viscosity of the mixture increased from 7.1 mPa s to 2980 mPa s for SIL2 and 5.1 to 1600 mPa s for SIL1. Melting points of the SILs 1 and 2 were at 8 and 14 °C, respectively. After the treatment time (5 days), the undissolved fraction contained 38 wt.% less hemicelluloses compared to native spruce. There was an increase in the glucose content of the milled spruce treated with both SILs, since the milling step reduced the cellulose crystallinity of the wood and facilitated an easier SIL access into the wood. The solvents were very neutral in terms of lignin removal. Consequently, only about 2% of the lignin was removed from native wood. Moreover, a priori removal of the wood extractives did not influence the lignin removal.
AB - Switchable ionic liquids (SILs) made from alcohols, either hexanol or butanol, and CO 2 together with an amidine (1,8-diazabicyclo-[5.4.0]- undec-7-ene (DBU)) were investigated as dissolution/fractionation solvents for wood material. Both native spruce (Picea abies), and pre-extracted spruce were treated with either butanol SIL (SIL1) or hexanol SIL (SIL2) for 5 days at 55 °C under normal pressure. The SILs were formed by bubbling CO 2 through an equimolar mixture of either 1-hexanol or 1-butanol and DBU. The viscosity of the mixture increased from 7.1 mPa s to 2980 mPa s for SIL2 and 5.1 to 1600 mPa s for SIL1. Melting points of the SILs 1 and 2 were at 8 and 14 °C, respectively. After the treatment time (5 days), the undissolved fraction contained 38 wt.% less hemicelluloses compared to native spruce. There was an increase in the glucose content of the milled spruce treated with both SILs, since the milling step reduced the cellulose crystallinity of the wood and facilitated an easier SIL access into the wood. The solvents were very neutral in terms of lignin removal. Consequently, only about 2% of the lignin was removed from native wood. Moreover, a priori removal of the wood extractives did not influence the lignin removal.
KW - Hemicelluloses
KW - Switchable ionic liquids
KW - Treatment temperature
KW - Wood fractionation
UR - http://www.scopus.com/inward/record.url?scp=83655201275&partnerID=8YFLogxK
U2 - 10.1016/j.carbpol.2011.10.006
DO - 10.1016/j.carbpol.2011.10.006
M3 - Article
AN - SCOPUS:83655201275
SN - 0144-8617
VL - 87
SP - 2005
EP - 2011
JO - Carbohydrate Polymers
JF - Carbohydrate Polymers
IS - 3
ER -