Quantitative Analysis of Functional Groups in Different Metamorphic Grade Indian Coals using FTIR technique

Abstract

To enhance the clean and economical feasible utilization of coal and reduce the coal or rock dynamic disaster, one should have an in-depth knowledge of coal macromolecular structures. In view of this, the chemical and physical structural properties of low to high-rank six Indian coals using Fourier transform infrared spectroscopy (FTIR) are presented. Four absorbance bands were identified in the subtracted spectrum for the functional group’s semiquantitative analysis in coal: hydroxyl, aliphatic, oxygen-containing, and aromatic structures associated with absorbance band at 3000–3600 cm-1, 2800–3000 cm-1, 1000–1800 cm-1, and 700–900 cm-1 respectively. Spectrum deconvolution technique was used to determine the FTIR structural parameters of coal samples. To investigate the structural transformation during coal metamorphism, correlations with Vitrinite reflectance (Ro) were formed. The present study will help to predict the conversion of organic groups to valuable liquids and gases from those samples. The macromolecular structure of coal could be useful to design the synthesis methods for carbon-based materials.