Value added products from sawdust pine in a biorefinery platform

CLAUSER, N.M.; GUTIÉRREZ, S.; AREA, M.C.; FELISSIA, F.E.; VALLEJOS, M.E.

Montevideo

Workshop; Workshop on Insights and Strategies Towards a Bio-Based Economy; 2016

Facultad de Química. Universidad de la República

The mainactivity of the production of wood pulp and products in Argentina isconcentered in Misiones. Pine is one of the most important raw materials forthese industries. Pine sawdust is an important lignocellulosic waste of theprimary industrialization of wood. The valorization of pine sawdust using thebiorefinery platform could add new values chains into Argentina?s forestindustry and can serve as a model for the industry of other countries in theregion. The most typical largescale biorefinery scenario is based on theextraction of sugars from biomass to produce cellulosic ethanol, steam, andelectricity. Depending on the available raw material, there are numerousproducts that could be obtained from a small-scale biorefinery platform. Someadvantages of small-scale biorefineries (10 to 50 employees) are lower capitaland logistics costs, and lower inversion risk than those of large-scale ones,in addition to the possibility of labor occupation in rural areas.Theprocessing model of this work includes a sequential alkaline-acid fractionationof pine sawdust to remove extractives (alkaline treatment) and to solubilizethe hemicelluloses (acid steam explosion). Based on experimental data, theconsidered alkaline treatment is performed at 90 °C with 5% NaOH, liquid-solidratio of 5.5:1 and during 60 min. For steam explosion, a model to determine thecomposition of hemicellulosic sugars (glucose, mannose, galactose, and xylose)of the liquid fraction and the solid yield was developed as a function of time,temperature, and acid concentration.Once themodel was established, the problem to be solved consists to find an optimalcondition for maximum total concentration of hexoses. The constrained NLPproblem to be solved is presented below.