Kinetic study of decomposition of wheat distiller grains and steam gasification of the corresponding pyrolysis char

Thermal characteristics of wheat distiller grains (WDGs) and steam gasification kinetics of the corresponding pyrolysis char were studied by thermogravimetric analysis. The pyrolysis process of WDGs can be divided into three stages including the drying, devolatilization, and carbonation. The heating rate and final temperature are the most important factors influencing the WDGs decomposition. The ultimate mass loss increases with increasing final temperature while the mass loss rate and the characteristic temperature for the maximum reaction rate increase with the increasing heating rate. For the pyrolysis of WDGs, the average activation energy was calculated as 77.45 kJ mol(-1) by Coats-Refern method. While for the steam gasification of the pyrolysis char, the shrinking-core model fits the gasification behavior better than the volumetric reaction one and the activation energy, and the pre-exponential factor were calculated to be 199.19 kJ mol(-1) and 7.21 x 10(6) s(-1), respectively, with the former model.