1-01: Switchgrass, cell walls and pyrolysis

Switchgrass (Panicum virgatum L.) biomass can be utilized to generate biofuels using biochemical or thermochemical platforms.  Whereas many of the issues confounding biochemical conversion have been identified, how plants with differential biochemical conversion properties behave in thermochemical platforms has received less attention.  Here, we have used stems from twelve switchgrass genotypes well-characterized with regard to biomass quality and conversion to ethanol to understand how cell wall composition and architecture affect yields of products obtained in an pyrolyzer. Yields for several groups of compounds were influenced by the presence or absence of the catalyst. In particular, acids were more prevalent in the absence of the catalyst, while aromatics were significantly enriched in the presence of the catalyst.  Significant differences in the recovery of a number of phenolic compounds were attributable to the changes in cell wall composition and architecture in the plants analyzed.  These differences in turn were the result of divergently breeding plants for ruminant digestibility.  Overall, these data indicate that switchgrass germplasm can be bred for improved conversion in thermochemical platforms.