Our working hypothesis is that highly effective oxidation of lignin polymers by hydroxyl and oxygen free radicals generated by TiO2/ZnO-nanocatalysts under UV can be utilized to significantly enhance the efficiency of lignin removal and alteration in biomass pretreatment, which will lead to improved digestibility of the biomass for subsequent enzymatic bioconversion. The objectives in this study are to further prove the validity of this hypothesis by investigating the compositional and configurational changes of lignin molecules caused by photodegradative reaction using spectroscopic imaging (i.e., Raman and NMR). This method was tested using corn stover biomass under various conditions, and the operational parameters were optimized to obtain elevated digestibility in the treated biomass for subsequent bioconversion.
2-48: Various effects of photocatalytic pretreatment of corn stover using TiO2 / ZnO assisted soaking in aqueous ammonia (SAA) method
Monday, April 30, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Pretreatment of lignocellulosic biomass is a critical step in bioconversion that removes the physical and chemical barriers (e.g., lignin) limiting the accessibility of enzymes to the cellulose substrate, and results in the increased digestibility of the biomass for subsequent bioconversion. Conventional pretreatment processes require higher energy and chemical loadings, which may lead to negative environmental impact and high production costs. In this study, we propose to enhance lignocellulosic biomass pretreatment process by utilizing photonanocatalyst for photodegradative lignin removal and alteration, and to achieve higher enzymatic digestibility of the biomass with reduced chemical loadings.