Bioresour Technol. 2014 ;155:307-13.
Yamamoto M1, Iakovlev M2, van Heiningen A3.
1Department of Forest Products Technology, Aalto University, FI-00076 Aalto, Finland. Electronic address: [email protected]
2Department of Forest Products Technology, Aalto University, FI-00076 Aalto, Finland.
3Department of Forest Products Technology, Aalto University, FI-00076 Aalto, Finland; and
Department of Chemical and Biological Engineering, University of Maine, 5737 Jenness Hall, Orono, ME 04469-5737, USA.
SO(2)-ethanol-water (SEW) fractionation of forest residues (tree tops, stumps, branches) was investigated to demonstrate the potential of this method for forest biorefineries. The effect of fractionation time on dissolution of wood components was studied. Total mass balances of fractionation show that lignin and hemicelluloses are rapidly dissolved in the spent fractionation liquor whereas cellulose is fully preserved in the solid residue throughout the fractionation treatment. Within 20min treatment at 150°C (SO(2):EtOH:H2O=12:43.5:44.5, by weight, L:W ratio 6Lkg(-1)), 89% of hardwood lignin and 74% of hemicelluloses are dissolved. The corresponding values for softwood biomass are 64% and 74%, respectively, indicating slower delignification but equal hemicellulose removal. Additionally, sulfur content of the feedstocks, solid fractionation residues and spent liquors were analyzed to determine the degree of lignin sulfonation. The obtained results are compared with the stem wood fractionation results.
Copyright © 2014 Elsevier Ltd. All rights reserved.