Kinetic mechanism for pyrolysis process of cotton stalk by double extrapolation method

The pyrolysis process of cotton stalk was studied in nitrogen atmosphere by using the thermogravimetric analysis. The kinetic mechanism of the process was determined and corresponding kinetic parameters were calculated by double extrapolation method. Thermogravimetric analysis results show that the pyrolysis process can be divided into three stages: evolution of water (<150℃), devolatilization (200～400℃) and carbonization (>400℃). The kinetic analysis results show that Jander equation G(&)=[1/(1-&)1/3]2 and Z?L?T equation G(&)=[1/(1-&)1/3-1]2 are the most probable mechanism functions when the degree of conversion & is in the ranges of 0.15～0.4 and 0.7～0.9 respectively, which indicates that the primary pyrolysis process is three-dimensional diffusion.