Comparison of two pretreatments methods to produce second-generation bioethanol resulting from sugarcane bagasse

Non-centrifugal cane sugar (NCS) is a high carbohydrate-content food obtained by boil evaporation of the sugarcane juice. In the manufacturing process, the by-product of NCS called bagasse is used as foul for the boilers, underestimating its potential as a lignocellulosic source for second-generation bioethanol. In order to assess the bioethanol potential of the by-product resulting from the NCS production, pretreatments were applied to breakdown the lignocellulosic structure for the study in hand. Therefore, this study carried out a comparison of two pretreatment methods steam explosion (SE) and acid hydrolysis (AH) applied to the sugarcane bagasse to produce second-generation bioethanol. It was evidenced that both pretreatments redistribute lignin and hemicelluloses and enhances the accessible surface area of the biomass which further benefitted the subsequent fermentation process as the reducing sugars were available enough to foster the production of bioethanol. The study found that the SE pretreatment was likely to obtain more bioethanol as the reducing sugars (glucose) production outperformed other pretreatments under different residence times and concentrations. Considering the necessity to develop second-generation biofuel production, this study presented the sugarcane bagasse as a promising and abundance lignocellulosic substrate to be investigated more in depth in the Colombian context.