Pretreated sugarcane bagasse with citric acid applied in enzymatic hydrolysis.

Abstract

The objective of the study was to evaluate the pretreatment of sugarcane bagasse (SCB) with diluted citric acid solution in a pressurized system and its behavior when submitted to enzymatic hydrolysis using the Cellic CTec 3 enzyme complex, employing a Doehlert’s experimental design (23 ), with 5 central points (CP). The operating variables were temperature (T, °C), time (t, min) and percentage by weight of citric acid in relation to bagasse (PCA, wt%), ranging from 120 to 180°C for 20 to 90 min and 3 to 12 wt%, respectively. The pretreatments were effective in promoting changes in compositions of lignin, hemicellulose, and cellulose in all samples in relation to raw SCB. The concentrations of the glucose reached the maximum, 23.74 g/L, for the pretreated sample with temperature of 160°C, PCA 5.25 wt%, and reaction time of 20 min, while the xylose reached the maximum, 5.23 g/L, with the sample ob tained in the temperature of 150 C, PCA 7.5 wt% and 55 min.