Study on the Oxidation Kinetics and Microreactivity of Water-Immersed Coal

Both the macroscopic reaction and microscopic characterization of water-immersed coal have been studied. The methods of thermogravimetric analysis via Fourier transform infrared spectroscopy (TG-FTIR) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) are used. The apparent activation energy of water-immersed coal was significantly lower than that of raw coal. For the same coal sample, the production of CO in water-immersed coal is significantly higher than that in raw coal. The analysis shows that after water immersion, the content of hydroxyl and aromatic hydrocarbons in the coal increases significantly and the temperature at which fat-based and oxygen-containing functional groups participate in the reaction decreases. This indicates that the functional groups are unstable after water immersion and react violently. When the immersion time is 60 days, the activation energy is the lowest, the production of CO reaches its maximum, and the variation of each functional group is most obvious.