Pretreatment of Douglas fir wood biomass for improving saccharification efficiencies

The main aim of this study was to analyze dilute acid pretreatment for the Douglas fir wood in order to improve the efficiency of hydrolysis with an ultimate aim to produce bioethanol. Compositional analysis of the untreated Douglas fir biomass revealed the presence of 63.3 % carbohydrate of which 57.2 % was C6 sugars. The total lignin content was approximately 30 %. A partial fractional factorial design was opted for performing the pretreatment experiments employing sulfuric acid (H2SO4). Acid concentration, solids loading, residence time, reaction temperature, and particle size of feedstock were evaluated simultaneously for improving the enzymatic digestibility of Douglas fir biomass. Enzymatic saccharification of the pretreated biomass was done using a commercial cellulase preparation and the total reducing sugars liberated was monitored. Saccharification efficiency was correlated with the parameters and the best combination of parameters for obtaining feedstock suited for enzymatic saccharification was determined.