Thermal Decomposition Kinetics of Raw and Water Immersed Coal of Raniganj Coalfield Region West Bengal, India

In this work, coal samples were collected from the Kottadih and Kalimati mines of Raniganj Coalfields (RCF). Kottadih is an underground coal mine and Kalimati is an open-cast coal mine, and the samples were divided into two parts. One part of the samples (raw coal) was analyzed by proximate analysis, Thermal Analysis viz Thermo gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) and spectral Analysis i.e. Fourier Transform Infra-Red spectroscopy (FTIR) and the other part of the samples were immersed in water at a ratio of 1:10 for 15, 30, 90 and 180 days. Spectral and kinetic behaviour of water-immersed coal was also studied. In raw coal and water-immersed coal, the dehydration and desorption reaction occur between 40 and 130 °C. The combustion stage is between 260 and 620 °C and finally burn out or decomposition stages start from 620 to 850 °C, the combustion and burnout stages of water immersed coal decreases. The FT-IR analysis of raw coal shows the presence of –OH, –Ar, –CHO, >C=O, >C=C< etc in small amounts and the concentration of these organic functional groups is comparatively higher in water-immersed coal samples. Due to these results, the propensity for spontaneous combustion/fire increases in both water-immersed coal samples of Kottadih and Kalimati mines of RCF.