Fractionation of Pinus radiata wood by combination of steam explosion and organosolv delignification

• Autores: Camila M. Imlauer Vedoya, Priscila Vergara Alarcón, María Cristina Area, Esteban Revilla, Fernando E. Felissia, Juan Carlos Villar
• Localización: Maderas: Ciencia y tecnología, ISSN 0717-3644, ISSN-e 0718-221X, Vol. 21, Nº. 4, 2019, págs. 587-598
• Idioma: inglés
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• Resumen

  • This work proposes a sequential combination of steam explosion and organosolv delignification for Pinus radiata fractionation. An efficient pretreatment to fully optimize the use of lignocellulosic materials is the key to make a biorefinery profitable, especially for softwoods, known to be more recalcitrant than other lignocellulosic raw materials. Steam explosion has a dual effect on biomass as morphological and chemicalchanges are introduced. A delignifying stage has been stated to be necessary in order to ease hydrolytic enzymes accessibility to cellulose while avoiding non-productive bonds with the lignin present. Three steam explosion conditions were tested (170°C, 5 min; 180°C, 10 min; 170°C, 5+5 min) followed by an organosolv delignification stage, carried out at two different conditions (170°C, 60 min; 170°C, 90 min). All treatmentyields, delignification extent, and hydrolysis yields were determined to evaluate each stage. The steam explosion treatment did not produce high delignification extent. Maximum global delignification (50,4%) was achieved when combining the two-cycle steam explosion with the most severe post-treatment condition tested. Enzymatic hydrolysis of the cellulosic residue improved after organosolv delignification; however, hydrolysisyields did not exceed 35%. The chemical changes undergone by softwood lignins are presumably responsible for the low digestibility.