Biorefining of quinoa residues to biopolymers, advanced biofuels and biopesticides

Emerging technologies supporting a transition to a bio-based economy through increased production of lignocellulose-based biofuels, green chemicals and biomaterials are compatible with economic advances and poverty reduction. This project will focus on thermochemical pretreatment and enzymatic hydrolysis of quinoa stalks and seed coats, two abundant residues of Bolivian agriculture. While stalks will be directly pretreated, seed coats will first be processed to biopesticides and the solid residue will then be sent to pretreatment. The sugars produced in the enzymatic hydrolysis of both substrates will be bio-converted to exopolysaccharide-based biopolymers using a Bolivian bacterial strain, and to ethanol by yeast using high-solids concentration processes. Using high solids loads is advantageous with regard to product recovery economics, but it is challenging due to mass transfer limitations and to the accumulation of fermentation inhibitors. The current project intends to enhance the mass transfer by introducing a pre-saccharification step prior to the simultaneous saccharification and fermentation, and the inhibition problem will be alleviated with reducing agents. High ethanol titers will also be reached by adding molasses to the hydrolysates. A techno-economic evaluation of the different approaches will be performed. The research will result in efficient processes for conversion of lignocellulosic feedstocks and in a more diversified production of Bolivian quinoa sector