초록
<P><B>Abstract</B></P> <P>This paper considers the economic assessment and optimisation of a bioethanol production process using corn stover (CS) as the feedstock. This includes a comparison between the use of batch and fed-batch reactors with and without deacetylation. As a basis of the study, a kinetic model describing the co-fermentation of substrates producing ethanol using <I>Zymomonas mobilis</I> is proposed<I>.</I> The model extends work available in the literature to include acetate inhibition. The reported optimisation studies include realistic variations in feedstock quality, deacetylation, a mechanical pre-treatment stage and a green recovery system: extractive distillation with vapour compression. Results indicate that the use of fed-batch reactors using a deacetylation stage achieves an ethanol yield of between 267 and 334 L/ton dry basis of CS and economic potential of between 0.4 and 5.5 MM USD/year higher than the use of batch reactors. This also has the lowest energy requirements in the product recovery stage (3.2–3.4 MJ-fuel/kg-ethanol or 1.6–1.8 MJ/kg-ethanol). Omitting de-acetylation prior to hydrolysis/co-fermentation increases the minimum ethanol selling price and energy requirements by ~3–14% and ~8–30%, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fed-batch operation achieves a minimum ethanol selling price (MESP) of 2–2.3 $/gal. </LI> <LI> De-acetylation increases the final ethanol titer peak and reduces the MESP. </LI> <LI> Optimal reactor operating conditions vary with respect to the corn stover quality. </LI> <LI> Pre-hydrolysis is not required for fed-batch reactor operation to reduce MESP. </LI> <LI> A new kinetic model incorporating acetate inhibition has been developed. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>