Kinetics Modeling of Low-Rank Coal Pyrolysis Based on a Three-Gaussian Distributed Activation Energy Model (DAEM) Reaction Model

A three-Gaussian distributed activation energy model (DAEM) reaction model (3-DAEM) was successfully applied for the kinetics study on the thermal pyrolysis of four types of low-rank coals, based on their nonisothermal thermogravimetric data. It is found that 3-DAEM was feasible for the analysis of coal pyrolysis process, which can be divided into three stages, using the second derivative method for thermogravimetry (TG) curves and the Peakfit software for differential hermogravimetry (DTG) curves. Calculated kinetic parameters, including three mean activation energies (E-0), three standard deviations (sigma(E)), and two weights (w), were used to predict the, pyrolysis process, and the results agreed well with the experimental data. Furthermore, the kinetics parameters were found to have a strong relationship with the DTG curve shape and especially with the coal property. These results indicated that 3-DAEM provided a good way to process thermogravimetric analysis (TGA) data and understand the pyrolysis mechanism for low-rank coals.