Biorefining of Pinus pinaster Stump Wood for Ethanol Production and Lignin Recovery

Stump wood is a forest residue having significant valorization potential. The aims of this work were to exploit pine stumps as a carbohydrate and lignin feedstock, and to convert the carbohydrate fraction to bioethanol by simultaneous saccharification and fermentation (SSF). Pinus pinaster stump wood (PPSW) was delignified by the alkaline organosolv (AOS) process. Soda (SA) cooking was used as benchmark process. Higher pulp yields were obtained in AOS treatments, whilst SA pulp showed the highest cellulose content. In the SSF of PPSW pulps, high ethanol concentrations were obtained with high productivity and yield. AOS lignins were purer and had lower molar mass and dispersity index, which are important parameters in high‐value co‐product applications. Valorization of pine stumps as a feedstock has advantages such as alternative solid‐waste management for forestry companies, solving environmental issues including fire risks, and potential for different applications. Herein, alkaline organosolv treatments were applied to recalcitrant pine stumps to obtain cellulose and lignin resources, and the carbohydrate fraction was converted to bioethanol.