Monday, April 30, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Aiming the utilization of sugar cane straw as raw material for the production of bioethanol, the goal of this work was to evaluate the best conditions for two types of pretreatments, hydrothermal and ultrasound, in order to obtain a material with high saccharide yield and low formation of inhibitors. For hydrothermal pretreatment, it was studied two temperatures, 160 and 180 ° C, and the times of 10, 20, 30, 40 and 50 minutes, under a ratio solid:liquid of 1: 10 (w / v). For ultrasound, the tests were carried out in a medium with 1% NaOH (w / v) or 1% H2SO4 (w / v), in the times of 1, 5, 10, 15, 20, 25 and 30 minutes, 25 ° C. The frequency of the equipment kept constant (40 kHz) and the ratio solid:liquid was 1:10 (w / v). Yields were determined for both reaction processes of pretreatment, and for the hydrothermal treatment, the best yields were 82% and 78.92% for periods of 10 and 20 minutes, respectively, at a temperature of 160 ° C. In the case of pretreatment with ultrasound, both in alkaline and in acid medium, the yields achieved were similar, around 85%. Subsequently, chemical characterization of samples submitted to hydrothermal treatment to quantify the levels of cellulose, hemicellulose and lignin was performed. There was a greater preservation of cellulose at 160 ° C and of 20 minutes. The same procedure was performed to characterize the samples treated by ultrasound and these analysis are underway.