(523b) Isoconversional Methods Applied to Kinetic Modeling Oxidative Alkaline Pretreatment of Sugarcane Bagasse

Delignification (decrease of lignin content) has shown to be a valid method to significantly increase lignocellulosic feedstocks digestibility. This operation (widely known as pretreatment) makes these abundantly available and inexpensive feedstocks usable in fermentation processes whose main goal is to produce biofuels and other chemicals. Because pretreatment is one of the most expensive processes in biofuels production plants, it has been extensively studied; however, a throughout literature search shows that development of kinetic models  to better understand, optimize and control pretreatment, are very scarce if available at all.

This study uses sugarcane bagasse which is a residue from the sugar industry abundantly produced particularly near and in the Equator zone.  This lignocellulosic resource is traditionally used in combustion processes to supply energy to the production plant; however life cycle analysis have shown that if lignocellulose is used as substrate in fermentation processes, the energy yield would be much closer to the theoretically available energy.

In this work, sugarcane bagasse is submitted to an alkaline pretreatment that uses an oxidative agent, systematically applied at widely varied ranges of temperature and time using a full factorial experimental design

Model fitting methods  do not achieve a clean separation between the temperature dependent Arrhenius constant and the reaction model. On the contrary, the isoconversional methods evaluate the activation energy values at progressive degree of conversion without modelistic assumptions. This work applies this methodology to calculate activation energy for alkaline pretreatment of sugarcane bagasse and compares with previous work where the traditional curve fitting is employed.