Metamorphic Grain Pyrolysis and its Kinetic Parameters by Different Methods

Metamorphic grain is one kind of biomass. Thermo- gravimetric analysis is used to study the pyrolysis characteristics of two metamorphic grains, metamorphic rice and metamorphic wheat in China, at different heating rates of 5degC/ min, 10degC/ min, 20degC/ min in a stream of N₂.Three methods: Coats-Redfern, Doyle and Kissinger, are used to determine the kinetic parameters, including reaction order, frequency factor and activation energies. The results indicate that the kinetic parameters are different with different methods. The pyrolysis process can be described by first-order global model for both metamorphic rice and metamorphic wheat, and activation energy adds along with the increase in heating rates and value of n, with the method of Coats-Redfern. Activation energy in Doyle model is a little smaller and changes in the range of 25 kJ/mol to 50 kJ/mol.