CBMS Lecture Series

Abstract: Sustainable bioprocessing methods have demonstrated efficacy in producing carbon materials, advanced fuels, and value-added products while benefiting current energy, economic, and climatic challenges. This study employs scattering techniques to understand processing-structure-property relationships of lignin-based carbon composites containing both crystalline and amorphous domains. Different lignin types are evaluated to relate materials' atomic- and micro-structures and mechanical properties with biomass feedstock, extraction methods, and processing conditions. Small and wide-angle X-ray scattering experiments were performed to gain insights of pore distributions and degree of graphitization as a function of carbonization treatments. Moreover, physics-based models based on a hierarchical decomposition of the radial distribution function were developed to allow rapid interpretation of scattering data and reason on the contributions of crystalline and amorphous domains, as well as their interfaces. Pair distribution functions show changes in the material structure and support the observation that graphitic structures form and increase in growth size as temperature increases during treatments. Lastly, at USDA-ARS integration of biological and chemical biorefining studies are carried out for the design of chemicals and fuels. An extension of this work focuses on the development of new pretreatment processes of cellulosic biomass for subsequent enzymatic production of fermentable sugars. Self-made Na2CO3 is used in pretreatment processes for agricultural residues and energy crops demonstrating reutilization of captured CO2 from industrial fermentation off-gases. Advanced materials, energy storage, and biochemicals are areas of significance where enabling lignocellulosic biomass can serve in a variety of target specific applications.