(580c) Exploring 3D Nanostructure and Topochemical Distributions of Lignocellulosic Biomass and Their Impact On Biomass Pretreatment

Lignocellulosic biomass consists of three major compounds including cellulose, lignin and hemicellulose and small amounts of extractives comprising approximately 90% of the dry weight of these plant materials. Each of these four components has a different degree of resistance to chemical, thermal and biological degradation.4 The chemical and biochemical structure has been perfected by nature to resist degradation and maintain the integrity of biomass. Pretreatments and conversion techniques deconstruct the complex plant cell wall to release the components of the biomass ( [i], [ii], [iii], [iv]). Acid, alkaline and enzymatic approaches show varying yields and degrees of success of biomass conversion (^{7, 12}). There has been very little effort in understanding the chemical and morphological characteristics of secondary cell walls and how they are influenced by biomass conversion strategies ([v], [vi]). Currently available pretreatment techniques used in the conversion of biomass to chemicals and energy provide a broad range of choices that improve the conversion of carbohydrates from lignocellulose biomass to biofuels, biochemicals, and biomaterials. In general, these techniques focus on disrupting the protection of cellulose and hemicelluloses by lignin, as well as weakening the dissociation between these constituents.  While these pretreatment methods are adjusted to the structure and properties of the biomass raw material chosen, they neither provide adequate yields of fermentable glucose from cellulose, nor are economically sound or energy efficient. To overcome the tradeoff between high yield and energy usage research must clarify the chemical pathways which constituents undergo during the pretreatment methods. Understanding of the ultrastructure and topochemistry of the cell wall constituents during pretreatments will lead to the improvement of the yields of fermentable sugars while reducing the energy consumption improving the cost model of production to these alternative bioproducts. The efficacy of enzymatic complexes to hydrolyze these substrates is inextricably linked to the innate structural characteristics of the substrate and/or the modifications that occur as saccharification proceeds.

A discussion of the application of new techniques including immunoassay labeled nanoparticle tags, correlative imaging with AFM, nanoCT and Raman will be given. Representative examples of the applications to biomass samples is also presented.