Sustainable Production of Bioproducts from Giant Miscanthus: A Biorefinery Approach

urrently, biorefinery platforms are aimed at replacing petrochemical refineries, thereby reducing the intensity of fossil fuel usage in different production areas. It is vital then, to investigate and develop biorefinery platforms based on abundant renewable resources such as lignocellulosic biomass, to improve on their economic potentials, making them competitive with the petrochemical industry. This work looks at developing a green biorefinery platform based on Miscanthus x. giganteus (MxG) to produce bioethanol and lactic acid, using the solid and liquid fractions of the Miscanthus plant. Wet fractionation through mechanical pressing was able to fractionate Miscanthus into liquid and solid fractions with a mass distribution of about 0.44 g/g of solid and 0.53 g/g of liquid. Furthermore, liquid hot water (LHW) pretreatment and dilute sulfuric acid pretreatment (DSAP), coupled with simultaneous saccharification and fermentation (SSF), using a cocktail of enzymes, including cellulase and hemicellulase were found to be effective in producing bioethanol from MxG solid fractions with high theoretical ethanol yields of above 70%. Saccharomyces cerevisiae was also found to be an efficient fermenting organism in producing bioethanol from Miscanthus solid fraction. Miscanthus juice was proved to be a good nutritional supplement for microalgal growth and was used to successfully cultivate saccharomyces cerevisiae, lactobacillus brevis and lactobacillus plantarum. MxG juice was further used as a substrate for producing lactic acid, with co-fermentation using L. brevis and L. plantarum producing a higher concentration of 1.19 g/L of lactic acid. A techno-economic analysis of a biorefinery that produces ethanol from Miscanthus resulted in a minimum ethanol selling price (MESP) of...