Comparison of fatty and resin acid composition in boreal lodgepole pine and Scots pine for biorefinery applications

To investigate the potential for Scots- and lodgepole pine for biorefinery applications such as e.g., biodiesel and glue production, wood samples from five different sites in northern Sweden were compared. 21 fatty and 10 resin acids were detected by extraction and GC-MS analysis. Total fatty- and resin acid contents of Scots pine varied between 2.4 and 41.4 mg/g. Corresponding concentrations for lodgepole pine were 2.3 and 26.0 mg/g of dry material. Multivariate models were made with principal component analysis to take advantage of the multivariate correlations between the individual acids. Wood tissue type explained most of the variation in fatty and resin acid content, with heartwood having up to five times the extractive concentration of sapwood. Resin acids were mainly associated with heartwood, while fatty acids were more associated with sapwood. A five-component PLSDA-model distinguished between the two species, mainly due to differences in their hexadecanoic and heptadecanoic acid contents. Heartwood from Scots pine is more suitable for resin extraction while lodgepole pine is a better option for fatty- and resin acid extraction because of the extractives' evenly distribution between wood types. Around 150 kg of fatty acids and 1 ton of resins can be harvested per hectare from a typical mature boreal lodgepole pine stand, for biorefinery use. Systematic fractionation and selection of heartwood and sapwood will likely optimize industrial applications (e.g. biodiesel production) of each fraction.