Thermal Decomposition Study of Isolated Lignin Using Temperature Modulated TGA

Abstract

Temperature modulated TGA (MTGA) was utilized to study the kinetics of lignin pyrolysis. Three industrial lignin preparations were investigated: softwood kraft lignin, hardwood kraft lignin, and Alcell lignin. Unlike conventional TGA, MTGA provides apparent activation energy (E _a ) distribution curve using a single experimental run in a relatively short experimental time. Under Hi-Res conditions using a dynamic heating rate, the activation energies were higher than those determined using a constant heating rate. Likewise, small sample masses provided higher activation energies than those run with large sample mass. These effects can be eliminated by using a relatively large sample mass, > 10 mg. In this study, we discuss the effect of MTGA conditions on calculating E _a distribution curves for lignin pyrolysis.

Keywords:

• Activation energy
• hi-resolution TGA
• lignin pyrolysis
• modulated TGA

The authors acknowledge NSERC for financial support of this research. We also acknowledge Dr. Jennifer L. Braun for her helpful discussion of this research