Comparison of sugarcane bagasse features that affect enzymatic hydrolysis after alkaline, organosolv and hydrothermal pretreatments
Monday, April 28, 2014
Exhibit/Poster Hall, lower level (Hilton Clearwater Beach)
Ursula F. Rodríguez Zúñiga1, Gislene M. Silva2, VIviane M. Nascimento2, Lucia Daniela Wolf3, Cristiane S. Farinas4, Raquel L. C. Giordano2, Antonio J. G. Cruz5 and Roberto C. Giordano2, (1)Chemical Engineering Department, São Carlos, Brazil, (2)Chemical Engineering Department, Federal University of Sao Carlos, Sao Carlos, Brazil, (3)Chemical Engineering Department, Federal University of São Carlos, São Carlos, Brazil, (4)Brazilian Agricultural Research Corporation - Embrapa, São Carlos, Brazil, (5)Chemical Engineering, Universidade Federal de São Carlos (UFSCar), São Carlos, Brazil
In this study, 35 samples of pretreated sugarcane bagasse were evaluated in terms to their composition and efficiency in the enzymatic hydrolysis. The pretreatments used were alkaline with Na(OH), organosolv with ethanol, and hydrothermal.

The results of these processes at different conditions of time, temperature and reagents concentration yielded 82% as the maximum concentration of cellulose for organosolv pretreatment (190ºC, 90 min and 50% v/v). At this condition, the lignin and hemicellulose removal were estimated as 78.3 % and 86.8 %. However, the highest conversion in enzymatic hydrolysis (88.2%) was observed with lower levels of lignin and hemicellulose solubilization and lower cellulose content (79.7 %). For the alkali pretreatment, the best condition used to attain the highest enzymatic conversion of the group (72%) was 120º, 30 min and 4 % (w/v). The substrate resulted in 75% of cellulose after a removal of lignin and hemicellulose of around 81.3 % and 83.9 %. The best condition for hydrothermal pretreatment (195° C, 10 min) yielded a lower removal of lignin and hemicellulose (3% and 80%) and a enzymatic conversion of 66 %.

With the conditions used here, the organosolv pretreatment was the process with highest standard deviation for the enzymatic conversion: ranging values between 88.20 - 12.20 %. The average of this group (19 samples) was 36.37%. The ratio: maximum/minimum % in enzymatic conversion yielded 9.28 and the high dispersion of the population indicates the validity of the whole group of samples for future structural analysis and their effect in enzymatic saccharification.