Tuesday, April 30, 2013
Exhibit Hall
Feedstock logistics, also known as biomass assembly (harvesting, storage, preprocessing and transportation), have not been widely studied by the biofuels community. Consequently, there is still a gap between feedstock suppliers and downstream biomass conversion and processing. In this regard, biomass size reduction has been proposed as an important variable in the biofuel production flow. While smaller particles are thought to be beneficial, wood size reduction is very energy intensive. For this reason, the objective of this study was to determine the influence of particle size on the bioconversion of steam pretreated hybrid poplar for sugar production. Five different particles sizes 0.2x0.2 cm, 0.4x0.4 cm, 0.4x1.2 cm, 0.7x0.4 cm and 1.9x0.8 cm were impregnated with SO2 and steam pretreated at 195˚C during 5 minutes. At an alpha level of 0.05, the different particle sizes did not influence the enzymatic digestibility of steam pretreated solids (5% consistency, 5 FPU/g cellulose, 2:1 β-G: cellulose), obtaining a cellulose-glucose conversion in a range of 78 – 82% for all the particle size under study after 72 hours of enzymatic hydrolysis. In terms of inhibitors, at an alpha level of 5%, the concentration of acetic acid did not show statistical difference among the different sizes. Nevertheless, there was a statistical difference in the concentration of 5-hydroxymethylfurfural and furfural among the different particle sizes used in this research. In this paper, we also discuss the overall sugar recovery after steam pretreatment and enzymatic hydrolysis.