TG-FTIR analysis of switchgrass pyrolysis

Switchgrass is a high yielding perennial grass that has been designated as a potential energy crop. One method of converting switchgrass to energy is by thermochemical conversion to syngas. This requires that the rate of thermal decomposition of switchgrass and the rate of production of components of the syngas be quantified. Ground switchgrass was pyrolyzed at heating rates of 10-40 degrees C/min in a thermogravimetric analyzer coupled to a Fourier Transform infrared spectrometer. The amount of gases (ppm) that were volatilized during the duration of experiment was quantified. The pyrolysis process was found to compose of four stages: moisture evaporation, hemicellulose decomposition, cellulose decomposition and lignin degradation. The peak temperature for hemicellulose (288-315 degrees C) and cellulose degradation (340-369 degrees C) increased with heating rate. FTIR analysis showed that the following gases were given off during the pyrolysis of switchgrass: carbon dioxide, carbon monoxide, acetic acid, ethanol, and methane. (C) 2009 Elsevier B.V. All rights reserved.