Energy along Interstate I-95: Pyrolysis kinetics of Floridian cabbage palm (Sabal palmetto)

Abstract

The efficient utilization of biomass as a renewable fuel relies on the identification of readily available fuel sources and an adequate description of their decomposition reactions. Cabbage palm (Sabal palmetto) is one potential local energy source for the Southeastern United States. The kinetics of pyrolysis of three particle size fractions (125–250, 250–300, 300–500μm) of cabbage palm leaf, stalk and trunk were examined using nonisothermal thermogravimetric analysis with heating rates of 25, 50 and 100°Cmin−1 under constant nitrogen flow. Using the Arrhenius equation to calculate the activation energy and pre-exponential factor, three distinct fractions, corresponding primarily to hemicellulose, cellulose and lignin, were found to decompose over three temperature ranges, each with distinct activation energies. The largest mass loss occurred in the mid-temperature fraction (40–45%); the low temperature region had approximately 30% mass loss and the high temperature region had 15–25% mass loss. Pyrolysis at higher heating rates decreased the activation energy of each palm material, whereas particle size was not correlated with activation energy. For leaf, stalk and trunk, activation energies ranged from 64 to 115, 67 to 152 and 19 to 25kJmol−1 for the low, medium, and high temperature range fractions, corresponding to hemicellulose, cellulose and lignin, respectively.