Two-stage fractionation process was suggested; (1) hemicelluloses hydrolysis using zinc chloride treatment in the first stage; and (2) lignin recovery after ethanol fermentation of treated cellulose using simultaneous saccharification and fermentation (SSF) in the second stage.
In the first stage, zinc chloride hydrolyzed mainly hemicelluloses (90-97%), whereas it preserved >90% lignin and >95% glucan with the solids. We also found that the treated solid, which contained glucan and lignin, can easily be converted to ethanol by fermentation in the second stage. With the treated solids, we’ve obtained significantly improve enzymatic digestibility (80-90%) and ethanol fermentation yield (80-90%) regardless of lignin content. Most of the lignins were precipitated after SSF.
The process conditions for effective pretreatment and fractionation were explored. Various effects on the compositional changes, enzyme digestibility, fermentability, recovery/utilization of each component, and other technical aspects related to development of process will be presented.