Biomechanics of Wheat/Barley Straw and Corn Stover.

A cost effective and sustainable supply of biomass feedstocks is a critical component of a viable biorefinery industry that is capable of making a credible impact on petroleum displacement. Feedstock costs can amount to a very significant fraction of the cost of the final biorefinery product. Thus, the reduction of the costs of feedstock production, harvest, collection, transportation, storage, and preprocessing can have a direct and positive effect on the overall viability of a given biorefinery. In addition, the feedstock and technology choices that are made for maintaining a sustainable biomass supply will have important implications not only for the biorefinery industry, but also for society as a whole. This session focused on feedstock supply, logistics, processing and composition, all of which are important elements of the feedstock supply chain.

Structural analysis of wheat stems.

Design and development of improved harvesting, preprocessing, and bulk handling systems for biomass requires knowledge of the biomechanical properties and structural characteristics of crop residue. Structural analysis of wheat stem cross-sections was performed using the theory of composites and finite element analysis techniques. Representative geometries of the stem's structural components including the hypoderm, ground tissue, and vascular bundles were established using microscopy techniques. Material property data for the analysis was obtained from measured results. Results from the isotropic structural analysis model were compared with experimental data. Future work includes structural analysis and comparison with experimental results for additional wheat stem models and loading configurations.

The effect of drying temperature on the composition of biomass.

The compositional quality of different lignocellulosic feedstocks influences their performance and potential demand at a biorefinery. Many analytical protocols for determining the composition or performance characteristics of biomass involve a drying step, where the drying temperature can vary depending on the specific protocol. To get reliable data, it is important to determine the correct drying temperature to vaporize the water without negatively impacting the compositional quality of the biomass. A comparison of drying temperatures between 45 degrees C and 100 degrees C was performed using wheat straw and corn stover. Near-infrared (NIR) spectra were taken of the dried samples and compared using principal component analysis (PCA). Carbohydrates were analyzed using quantitative saccharification to determine sugar degradation. Analysis of variance was used to determine if there was a significant difference between drying at different temperatures. PCA showed an obvious separation in samples dried at different temperatures due to sample water content. However, quantitative saccharification data shows, within a 95% confidence interval, that there is no significant difference in sugar content for drying temperatures up to 100 degrees C for wheat straw and corn stover.