M63
Isolation and characterization of organosolv and alkaline lignins from hardwood and softwood biomass
Monday, April 25, 2016
Key Ballroom, 2nd fl (Hilton Baltimore)
C. Nitsos*, U. Rova and P. Christakopoulos, Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering,Luleå University of Technology, Luleå, Sweden; R.J. Stoklosa and D.B. Hodge, Department of Chemical Engineering and Materials Science and DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, USA
Fractionation of the three major lignocellulose components, i.e. cellulose, hemicellulose and lignin, is a key step for efficient utilization of the whole biomass in the bio-based refinery. An increased significance is currently placed on lignin, which is the most underutilized biomass constituent, as well as the most potent barrier for the transformation of biomass carbohydrates into sugars and chemicals. A successful pretreatment method must therefore enable the isolation of lignin prior to the further processing of the biomass components. In this respect organosolv and alkaline pretreatment represent promising methods for the isolation of pure lignin fractions.
In the current work the fractionation of lignin from softwood (spruce) and hardwood (birch) biomass was performed by aqueous ethanol (organosolv) and alkaline pretreatment methods. Operational parameters for the organosolv pretreatment included biomass particle size, pretreatment time, ethanol concentration, addition of acidic catalyst (H2SO4),and the effect of explosive discharge at the end of the pretreatment. Lignin was precipitated by addition of water in the pretreatment liquid. For alkaline pretreatment, the effect of NaOH concentration on the extraction yield and the characteristics of the isolated lignin were examined. Lignin was fractionated and precipitated by adjustment of the pH in the pretreatment liquid. The isolated lignins from both biomass types and pretreatment methods were analysed for purity and characterized with GPC for determination of molecular weight, Py-GC/MS for the determination of G/S ratio and H-NMR for the determination of lignin functional groups.
