LAUSR

Abstract The devolatilization characteristics and non-isothermal kinetics of gaseous volatile evolution of bituminous coal were investigated through simultaneous thermogravimetry-mass spectrometry (TG-MS). The TG-MS results indicated that the three types of coals possess similar devolatilization characteristics in terms of mass loss and gas evolution. A high heating rate slightly shifted the TG, derivative thermogravimetric analysis (DTG), and MS curves to a high temperature range and promoted the release of evolved gases. The kinetic parameters of gaseous volatile evolution were determined through a novel procedure. In this procedure, the kinetic model function f (α) was identified using the Malek method, and the activation energy E and the pre-exponential factor A were calculated with common isoconversional methods or a distributed activation energy model (DAEM). With the Malek method, the reaction order model (n = 2) was the most probable mechanism to describe the gaseous formation of H 2 and C 2 H 2 . This finding implied that chemical reaction is a limiting factor of gas evolution. The evolved rate curve of CO 2 and CO could be fitted and identified by subjecting the spectral peaks to multi-Gaussian analysis. A JMA model (n = 3) and a standard Z-T-L model were applied to describe various kinetic stages. Results revealed that the evolved CO 2 and CO were mainly controlled by diffusion. All of the standard models failed to fit the gaseous evolution of CH 4 and H 2 O. Therefore, CH 4 and H 2 O possibly underwent a complex process involving different reactions and stages.