Bark Assortments of Scots Pine and Norway Spruce as Industrial Feedstock for Tall Oil Production

Fatty and resin acids in bark residues generated by forest industries can be used to produce high-value green chemicals, but more information about their concentrations in potential sources is required. We examined variations in the content of lipophilic extractives from both pulpwood bark and timber bark of Norway spruce and Scots pine trees growing in homogenous stands in mid-Sweden. We found that spruce pulpwood bark had the highest total amounts of fatty and resin acids (average yield, 0.9 kg/m(3) wood). The regression functions, based on readily available tree parameters (age, stem diameter, height, growth rate and inner bark proportions), can be used to predict the concentrations of fatty and resin acids, triglycerides, sterols and steryl esters in bark materials before harvesting stands that supply industrial plants.