Raman Spectroscopic Characterization of Photonanocatalyst Aided Alkaline Pretreated Corn Stover Biomass

Abstract

The most expensive and principal step in the process of converting cellulosic biomass into biorenewables and biofuel is the pretreatment during which lignin and cellulose crystalline structure is broken down. In this study, TiO2 nanoparticles were utilized as photocatalyst in addition to alkaline (ammonia and sodium hydrate) treatment of corn stover biomass to improve delignification ability and reduce the energy and chemical loadings to make the process more environmentally friendly. Raman Spectroscopic imaging, as an accurate and rapid chemical characterization method, was utilized to investigate the molecular compositional and structural changes occurring during the pretreatment process in the corn stover biomass qualitatively. Lignin characteristic peaks at 1,600, 1,620 and 1,690 cm-1 as well as cellulose characteristic peaks at 1,059 and 2,888 cm-1 were identified through Raman Spectroscopic measurement as indicators of the effects of the pretreatment. Real-time quantitative analysis of these functional peaks revealed the molecular structural changes during delignification, potentially may lead to optimization of the processing parameters to reduce the processing cost in the future.