13-06: Assessment of different conditions of the hydrothermal pretreatment of sugarcane straw and its influence on the enzymatic hydrolysis stage

This work aimed to evaluate the best conditions for the hydrothermal pretreatment in order to obtain a saccharide material with high performance and low formation of inhibitors, and also evaluating the effect of pretreatment in the saccharification stage. For the hydrothermal pretreatment two temperatures have been studied, 160 and 180 ° C, at times of 10, 20, 30, 40 and 50 minutes, with solid/liquid ratio of 1/10. Reaction yields were determined for both treatment processes, being that for the hydrothermal treatment, the best yields were 82% and 78.92% for times of 10 and 20 minutes at a temperature of 160 ° C. A chemical characterization of samples was performed for quantitation of the levels of cellulose, hemicellulose and lignin. It was observed that the condition at 180 ° C in time of 10 min (exp 1), there was hemicellulose removal of about 50%, solubilizing only 19% of cellulose. In this condition it was also found an enzymatic conversion of cellulose at about 44%. Delignification of pre-treated straw was also performed with NaOH solution (1% w/v) by 1 h at 100 ° C. For the pulp obtained in the condition of the sample from exp. 1, it was found an enzymatic conversion of cellulose to about 98%. In this condition it was observed that the residual lignin content has the highest value (27%) when compared with other conditions, thus demonstrating that lignin present in this sample did not act negatively in the conversion of cellulose. [Acknowlegdements due to FAPESP, CAPES, CNPq]