Sequential Fractionation of Spruce Bark in a Continuous Flow-through System

Abstract

This study presents a sequential fractionation of spruce bark employing a flow-through system that enables continuous extraction without the need to change the chamber during the process. Various bark components such as lipophilic extractives, noncellulosic sugars, and lignin were extracted under mild conditions and within short timeframes compared to the batch process. The utilization of the flow-through system enabled efficient extraction without degradation of products that were observed during the batch process. By recirculating the solvents containing extracted components, the solvent/biomass ratio could be reduced considerably, without degradation of the products. The results demonstrate an energy efficient approach to obtaining valuable components from spruce bark, paving the way for a future biorefinery.