Compositional and kinetic study of thermal degradation of kerogen using TG‐FTIR, NMR, and microscopic study

Abstract

AbstractUnderstanding the thermal maturation mechanism of kerogen has both industrial and scientific significance. Here, kerogen extracted from Indian oil shale of Upper Assam basin is subjected to TG‐FTIR analysis to study the thermal decomposition behavior of isolated kerogen and compared with oil shale sample. Kinetic study of kerogen was performed on thermogravimetric data using isoconversional methods. The mean apparent activation energy values were found in the range of 219 to 236 kJ/mol. The reaction models were identified as first‐order and A2 nucleation models. The obtained kinetic parameters were validated by reconstruction of conversion profiles. Comparison of oil derived from kerogen with shale oil, and solvent‐extracted bitumen using NMR analysis showed that kerogen initially matures into bitumen, and thereafter, gets converted to oil and gas in the presence of inherent minerals. The predicted degradation mechanisms of kerogen from the parent oil shale sample were examined using microscopic study.