Enhancing bioethanol fermentation through removal of acetic acid using liquid-liquid extraction

The concern for the ever growing human population as well as the depletion of fossil fuel resources and their impact on global warming have long been motivations for the researchers to investigate means for sustainable producing carbon-neutral energy. Second-generation biofuel refers to liquid fuels that are produced from non-food resources and reduce the total greenhouse gas emission by at least 60 %. Acetic acid has been shown to be one of the most ubiquitous fermentation inhibitors in a bioethanol production facility which slows down the bioethanol production and reduces its yield through inhibition of the ethanol producing microorganisms. The use of liquid-liquid extraction has shown to be a viable tool to remove the acetic acid from corn stover hydrolysate. Extraction coupled with a solvent recovery unit enhances the bioethanol production through improving the product yield as well as its production rate. Economic assessment of the proposed system showed that incorporating the extraction unit within an industrial scale corn stover bioethanol production plant is a feasible option which can drop the MESP by up to $0.35/gal