Different Methods for Evaluating Pinewood Sawdust Pyrolysis Kinetics by Thermogravimetry Mass Spectrum Analysis

Two methods to simplify calculate kinetic parameters are applied to pinewood pyrolysis. Pinewood pyrolysis experiments were performed with thermogravimetry mass spectrum analysis (TG/MS), under N-2 atmosphere at heating rates of 10, 20, 30, 90 degrees C/min, respectively. H-2 (M/Z = 2), CH4 (m/z = 16), H2O (m/z = 18), and CO2 (m/z = 44) were detected by MS spectra. The results show: all pinewood TG curves can be divided into four reaction stages, i.e., drying, slow pyrolysis, fast pyrolysis, and carbonization; fast pyrolysis represents major pyrolysis stage accounting for around 54% of the total mass loss occurring. The peak of pinewood composition pyrolysis is in accordance with DTG curve, which validates the assumption of reaction stage. According to two methods developed, react order, activation energy and pre-exponential factor are obtained. Comparison is made between experimental data and calculated data as well as literature method. The well fitting results indicate that two methods are appropriate for simulating pinewood pyrolysis, and Method 2 is better than Method 1 and literature method.