Making Sustainable Biofuels and Sunscreen from Corncobs To Introduce Students to Integrated Biorefinery Concepts and Techniques

Abstract

To inspire upper-division undergraduate students to gain a deeper understanding of biorefinery, an experiment related to biofuels and lignin-based sunscreen products from corncob was performed in multiple offerings of a summer-semester class. Specifically, corncobs were pretreated with 1% H2SO4 to obtain hemicellulose hydrolysates, which were detoxified, and followed with oleaginous yeast fermentation to yield microbial lipids. The microbial lipids were chemically transesterified into biodiesel in situ by an alkali catalyst. Subsequently, dilute acid-pretreated corncob residue was enzymatically saccharified to release glucose for ethanol production by separation hydrolysis and fermentation. Finally, the resultant lignin from the cellulosic ethanol production was valorized to make sunscreen. The main objectives of this work are to introduce students to integrated biorefinery concepts and techniques so that they can learn how to obtain added-value products from waste materials and to evoke students’ awarene...