A kinetic research method for coal oxidation based on the Kubelka-Munk equation and the Starink method

Simultaneous thermal analysis and Fourier transform infrared spectroscopy in situ diffuse reflection technology were used to quantitatively study the quality and functional groups of lignite during the oxidation process according to temperature. The Kubelka-Munk equation and the Starink method were used to calculate the oxidation kinetics of functional groups for the first time. The results show that the oxidation and heating process of lignite varies in stages, including a water evaporation and desorption stage, an oxygen absorption and weight gain stage and a thermal decomposition stage. The main functional groups in coal include -OH, C = O, CH2/CH3, C = C and CH-, which exhibit different oxidation characteristics in each stage. This study provides a method for calculating the oxidation kinetics of functional groups, which overcomes the indirectness of the conversion of reference mass and can be used to reveal the different oxidation processes of various functional groups in the coal oxidation process.