(661e) How Do Feedstock Variabilities Impact the Convertibility of Lignocellulosic Biomass? a Data-Oriented Case Study on Corn Stover in the United States

The valorization of low-cost lignocellulosic wastes into biofuels and bioproducts contributes to a low carbon emission bioeconomy. Although it is widely acknowledged that the inherent variability of lignocellulosic biomass affects its conversion, no study thoroughly investigated the relationship between feedstock properties and conversion efficiency. Using corn stover as an example, this study employed a multiscale analytical characterization approach coupled with data analytic methods to understand some key critical material attributes of feedstock quality and elucidate their impacts on the subsequent conversion.

We observed a significant decrease in moisture and ash content for corn stover after one year of indoor storage, likely due to water evaporation and soil contamination reduction. No significant difference was found in volatile solids, fixed carbon content, elemental components, and cellulose crystallinity index across corn stover samples. The ash content, largely originating from the soil, significantly impacted the mineral composition of corn stover, with the highest SiO₂ content (12.2%) observed in high ash groups (ash content > 15%). Moisture content was closely related to biomass degradation during storage, with higher moisture content leading to more severe degradation, thus altering corn stover characteristics. Interestingly, self-degradation improved the sugar yields (glucose: from 21% to 45%), indicating the potential benefits of self-degradation. Different anatomic fractions (i.e. stalk, leaf, husk, and cob) demonstrated varied convertibility; pretreatment and self-degradation enhanced sugar yields. The correlation analysis highlighted the negative impact of lignin on sugar yields among corn stover samples with different ash and moisture content. However, no correlation was found between the variability (such as lignin content and cellulose crystallinity) and sugar yield, likely due to the deconstruction of the cell wall after self-degradation. This study emphasized the importance of optimizing pretreatment methods to enhance sugar yield and considering the balance between promoted sugar yields and mass loss during self-degradation.