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

IMLAUER, C.; VERGARA, P.; AREA, M.C.; REVILLA, E.; FELISSIA, F.E.; VILLAR, J.C.

Córdoba

Workshop; 1st International Workshop on Biorefinery of Lignocellulosic Materials (IWBLCM); 2015

Secondgeneration biorefineries are a promising alternative to the first generationbased on sugar plants or cereals. Lignocellulose is abundant and ubiquitous anddoes not compete with the foodstuff by the agricultural land because it can beobtained from agro-forestry residues. However, the exploitation of thepolysaccharides needs a pretreatment to make them accessible to the action ofenzymes or chemicals. Pretreatments improve the lignocellulose accessibility byremoving hemicelluloses and/or lignin and by reducing cellulose crystallinity.Forany pretreatment the energy/cost involved must not be greater than theenergy/benefit obtained from the biomass. Nowadays, physical and chemicalpretreatments are the most employed. Hydrolysis processes (hot water or steam)and dilute acid hydrolysis are commonly used although they can generateby-products which inhibit the further stages of saccharification andfermentation. Moreover, these pretreatments are usually applied to herbaceousand hardwoods residues but not to the coniferous species.Lignocellulosefractionation with solvents does not produce inhibitors; it is applicable toany type of vegetal species and produces a sulfur-free lignin with many potentialuses. The main bottleneck of this procedure is the cost of solvent recovery. Inthis work, a sequential combination of steam explosion and solventdelignification is proposed for the fractionation of Pinus radiata. Acellulose-rich solid (67%) could be obtained form P. radiata chips with this sequence of treatments and after 1 hourof delignification. The more important effect is that saccharification withenzymes of the cellulosic residue is clearly improved after solventdelignification.