초록
<P><B>Abstract</B></P> <P>Acid pretreatment (AP) is one of the most widely used processing step in the biochemical route of ethanol production from sugarcane bagasse. During AP, changes in structural features of bagasse, such as crystallinity and surface area, influence enzymatic hydrolysis (EH). Therefore, an integrated optimization study is performed by combining these two processes. Hot utility flow rate and acid concentration of AP are decision variables and the combined severity factor (CSF) of AP affects the EH yields. Three optimization studies, namely, yield maximization, profit maximization of AP, and profit maximization of AP and EH together, are considered, and the actual profit for combined AP and EH for the optimal operating condition recommended by each study are compared. The results showed that combined profit maximization improved in the actual profit as compared to yield maximization study by as much as 18–130 % across various combinations of solid loading and batch times. The benefit was due to implementation of less severe conditions in AP, reflected in 7–13 % reduction in CSF. However, it was also observed that the benefit of combined profit maximization over profit maximization of AP was a function of enzyme cost. The benefit was marginal for low enzyme cost of 0.85 $/kg, but increased up to 13.6 % for the enzyme cost of 3 $/kg. Sensitivity analysis was performed to identify batch time and enzyme cost as key exogenous parameters.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Integrated model was developed for acid pretreatment and enzymatic hydrolysis. </LI> <LI> Actual profit from integrated model was mainly affected by cost of enzyme. </LI> <LI> Sensitivity analysis under exogenous uncertainties performed for integrated model. </LI> <LI> At low cost of enzyme hot utility flow rate and batch time are important. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>