Batch and fed-batch enzymatic hydrolysis of pretreated sugarcane bagasse – Assays and modeling

Choosing the right pretreatment for a specific biomass in order to improve sugar recovery is a key step towards the commercial feasibility of cellulosic ethanol. This article deals with the enzymatic hydrolysis of sugarcane bagasse subjected to either delignification or hydrothermal pretreatment. Two operational strategies were studied: batch experiments were carried out with different solids loads (5–20% w/v) and fed-batch tests reached cumulative solids content of 24% (w/v). The highest glucose concentration (127 g/L) was achieved when working with the delignified material in fed-batch systems. However, the reactions using delignified bagasse presented sharp decrease in conversion when the solids loads exceeded 15% (w/v). During the modeling phase, the hydrolysis behavior was described according to a semi-mechanistic approach. The goodness of fit evaluation showed that the models performed well when compared to the collected data. Finally, fed-batch simulations suggested new feeding polices to increase the final glucose content.