Effect of pelleting on the enzymatic digestibility of corn stover

Pelleting of lignocellulosic biomass to improve its transportation, storage and handling impacts subsequent processing and conversion. This work reports the role of high moisture pelleting in the enzymatic digestibility of corn stover prior to pretreatment, together with associated substrate characteristics. Pelleting increases the digestibility of unpretreated corn stover, from 8.2 to 15.5% glucan conversion, at 5% solid loading using 1 FPU Cellic & REG; CTec2 per g solids. Compositional analysis indicates that loose and pelleted corn stover have similar nondissolvable compositions, although their extractives are different. Enzymatic hydrolysis of corn stover after size reduction to normalize particle sizes and removal of extractives confirms that pelleting improves corn stover digestibility. Such differences may be explained by the decreased particle size, improved substrate accessibility, and hydrolysis of cross-linking structures induced by pelleting. These findings are useful for the development of processing schemes for sustainable and efficient use of lignocellulose.

Automated summary

This study reports the role of high moisture pelleting in improving the enzymatic digestibility of corn stover for ethanol production. Pelleting increases the glucan conversion from 8.2% to 15.5% at 5% solid loading. The composition analysis shows that loose and pelleted corn stover have similar nondissolvable compositions, but their extractives are different. The improved digestibility may be attributed to decreased particle size, improved substrate accessibility, and hydrolysis of cross-linking structures induced by pelleting.