(779a) Understanding the Pretreatment Chemistry of Softwoods

Recalcitrance of lignocellulose is a major barrier to the economical development of biobased fuels and products. To overcome the recalcitrance of lignocellulosic biomass, many chemical, thermal and biological pretreatments have been proposed. The effectiveness of the pretreatments has been done mainly based on the sugar yield and the hydrolysability of resulting substrate. There is a little understanding of the reaction chemistry occurred during these pretreatment methods.

In this study, we evaluated the pretreatment of softwood species in the Pacific Northwest region by using sulfite, wet oxidation and diluted acid pretreatment methods. The effects of different pretreatment chemistries on the structure of biomass, production of chemical intermediates, carbohydrate recovery and enzymatic hydrolysability of pretreated substrate biomass were determined. The structural changes occurred on the biomass lignin and carbohydrate during various pretreatment conditions were investigated by HPLC, GC/MS, and NMR. The results obtained from this study can help us to optimize softwood pretreatment process to maximum the production of biofuels and biobased products.