Tuesday, April 20, 2010
LL Conference Facility (Hilton Clearwater Beach)
Bioethanol is a renewable energy source produced by fermentation of sugars. In these days because of high price of edible biomass, inedible biomass such as lignocellulosic biomass from wood was widely researched. Lignocellulosic biomass, however, needs pretreatment to hydrolyze because of high lignin contents. As an alternative waste raw material, rapeseed straw was studied for sugar production, and obtained from a local field. Cellulase from Trichoderma reesei ATCC 26921 (Celluclast 1.5L, Novozymes, Demark) and β-glucosidase from Aspergillus niger (NS-50010, Novozymes, Denmark) will be used for enzymatic hydrolysis.
Prior to pretreatment, chemical compositions were analyzed. Rapeseed straw composed of 68.32% holocellulose, 20.99% lignin, 1.02% fat and 8.9% ash. Holocellulose and lignin composition will be analyzed in every pretreatment condition.
Pretreatment will be carried out in the minibomb (500mL). Materials will be pretreated by sodium hydroxide with various conditions, such as concentration (0.5-2%), temperature (160-200°C), treatment time (5-30min) and solid content (10-20%). Then, pretreated mixtures will be washed with distilled water and divided into the solid and liquid fraction. Enzymatic hydrolysis will be performed with 1g of pretreated materials (solid fraction) in 100ml of 0.05M acetate buffer (pH 5.0) containing enzymes. Mixtures will be incubated and sampled at 50°C in a shaking incubator at 150rpm. Digestibility and enzyme hydrolysis yield will be measured to determine the effect of pretreatment.
Further analysis will be required to obtain the optimal hydrolysis conditions of rapeseed straw for economically feasible production of ethanol.