(332b) Production and Characterization of Biochar from Individual Anatomical Fractions As Biorefinery Co-Products.

Fractionation of biomass enables tissue-specific processing of feedstocks at a biorefinery. Fractions meeting specifications can be processed to fuels and chemicals directly and fractions out of specification can be considered for additional processing to achieve a quality standard or to develop as a co-product. Biochar is a co-product of interest as it can be used to improve soil quality while also sequestering carbon. Little is known of the properties of biochar produced from individual fractions or how storage might affect biochar properties produced from individual fractions. The storage operation within a biorefinery offers the opportunity to condition feedstock using little energy or chemical input, taking advantage of the long residence time. Previous work showed that treatment of whole corn stover with formic acid before storage improved preservation and reduced pyrolysis activation energy. Pyrolysis-GC-GC/MS analysis also revealed improved lignol pyrolysis efficiency indicating formic acid-initiated lignin degradation in storage. Formic acid treatment in storage could therefore impact the properties of biochar produced in pyrolysis. To understand this potential, individual fractions of corn stover (cob, stalk, leaves, husk) were stored either without treatment or after treatment with formic acid. The stored material was then used as feedstock for biochar production, which was then characterized for yield, ash content, elemental composition, thermal recalcitrance, surface area, pH and electrical conductivity. Based on the outcome and techno-economic analysis the fractions best suited for biochar production were identified and preferred uses for the remaining fractions were suggested.