Implications of differences in macromolecular composition of stem fractions for processing of Scots pine
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Use of wood feedstocks for sugar-based biorefineries requires suitable treatments of the various tree fractions to optimize yields. In the current study, stem wood fractions (sapwood, heartwood and knotwood) were sampled at different heights from well-documented Scots pine trees taken from two contrasting stands. The fractions were assessed in terms of chemical composition, response to SO2-catalysed steam pretreatment and enzymatic digestibility. There were significant differences in total extractive contents between the fractions, where the heartwood fractions had an extractive content 1–3 wt% higher than sapwood (corresponding to a relative increase of 20–60 %) for samples at the same height. In contrast, the differences in macromolecular carbohydrate contents between the fractions were smaller and mainly insignificant. One exception was the xylan content, which was higher in heartwood than in sapwood at the same tree height (a relative difference of 10–15 %). Steam pretreatment resulted in a clearly higher degree of hydrolysis for sapwood than for heartwood at the same conditions. However, at optimal pretreatment temperatures a higher total sugar yield was in fact obtained for heartwood, showing the importance of tuning the process conditions for the respective wood fractions.
KeywordsLignin Xylose Hemicellulose Glucan Furfural
The authors are grateful for financial support from the Bo Rydin Foundation for Scientific Research to the project TALLRAFF.
- Björklund Jansson M, Nilvebrant N-O (2009) Wood extractives. In: Ek M, Gellerstedt G, Henriksson G (eds) Pulp and paper chemistry and Technology. Wood chemistry and wood biotechnology, vol 1. Walter de Gruyter, Berlin, pp 147–171Google Scholar
- Henriksson G, Brännvall E, Lennholm H (2009) Wood chemistry and wood biotechnology. In: Ek M, Gellerstedt G, Henriksson G (eds) Wood chem biotechnol. Walter de Gruyter, Berlin, pp 13–44Google Scholar
- Jozsa LA, Middleton GR (1994) A discussion of wood quality attributes and their practical implications. Canadian forest service publications special publication No. SP-34Google Scholar
- Lynd LR, Wyman C, Laser M, Johnson D, Landucci R (2005) Strategic biorefinery analysis: analysis of biorefineries. Subcontract report NREL/SR-510-35578Google Scholar
- Nilsson P, Cory N, Fridman J, Kempe G (2013) Forest statistics 2013: Official Statistics of Sweden. Swedish University of Agricultural Sciences, UmeåGoogle Scholar
- Sjöström E (1993) Wood chemistry: fundamentals and application. Academic Press, San DiegoGoogle Scholar
- Sluiter A, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D (2008a) Determination of sugars, byproducts, and degradation products in liquid Fraction process samples. Technical report NREL/TP-510-42623Google Scholar
- Sluiter A, Ruiz R, Scarlata C, Sluiter J, Templeton D (2008b) Determination of extractives in biomass. Technical report NREL/TP-510-42619Google Scholar
- Sluiter A, Crocker D, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D (2008c) Determination of structural carbohydrates and lignin in biomass. Technical report NREL/TP-510-42618Google Scholar
- Söderholm P, Lundmark R (2009) Forest-based biorefineries: implications for market behavior and policy. For Prod J 59:6–16Google Scholar
- Teleman A (2009) Hemicelluloses and pectins. In: Ek M, Gellerstedt G, Henriksson G (eds) Wood chem wood biotechnol. Walter de Gruyter, Berlin, pp 101–120Google Scholar