Thermal analysis of the pyrolysis and oxidation behaviour of 1/3 coking coal

Abstract

Pyrolysis is the initial stage of coal conversion during processes including combustion, gasification, and liquefaction. It has a direct effect on coal’s subsequent transformation. Pyrolysis plays a vital role in the efficiency of coal’s use and, like oxidation, can create hazards during non-combustion processing (such as during mining or transportation). Indeed, the spontaneous combustion of coal (a coal–oxygen reaction) can impact human health, lead to material damage and wasted resources, and damage the environment. To better understand this phenomenon, samples of bituminous 1/3 coking were taken from four different coal mines in Huainan (Anhui, China) and analysed. Thermogravimetry and differential scanning calorimetry are adopted to explore the samples’ thermal behaviour. The complex kinetics of the pyrolysis process are divided into four stages, while that of oxidation is divided into five. The influence of heating rates is analysed separately for oxidation and pyrolysis. Furthermore, the apparent activation energy is calculated for the combustion stage of the oxidation process, and curve fitting is used to identify the most probable mechanism function.