Effects of biomass particle size on steam explosion pretreatment performance for improving the enzyme digestibility of corn stover

Size reduction is an essential process for corn stover biomass utilization. Effects of biomass particle size on the efficiency of pretreatment and enzymatic hydrolysis are systematically investigated in the present study. Sugar recoveries and conversions of the biomass with particle sizes at 2.5, 2.0, 1.5, 1.0 and 0.5 cm were compared. The highest sugar recovery reached 99.6% for glucan and 67.0% for xylan at the particle size of 1.0 and 0.5 cm, respectively, but the highest sugar conversion (100% for glucan and 83% for xylan) was observed at the particle size of 2.5 cm. The enzymatic hydrolysis rate and conversion of pretreated biomass obviously increased with increasing biomass particle size. With increase of biomass particle size, the specific surface area of pretreated biomass significantly increased and the crystallinity index of pretreated biomass apparently decreased. In studied extent of particle sizes, the utilization of larger biomass particles would be desirable to achieve the high pretreatment efficiency and hence improve subsequent enzymatic hydrolysis performance compared with the smaller ones.

► Effects of particle size on bioconversion of biomass were systematically investigated.
► Sugar conversions were correlated with physicochemical characters of biomass.
► Effects of particle size were evaluated using mass balance for the conversion.