Kinetic Analysis of Carpathian Source Rock Pyrolysis Under Dynamic Conditions

The research presented in the article was undertaken in order to better investigate the generation potential of the Oligocene Menilite Formation due to its importance as source rocks within the Outer Carpathian Basin. The non-isothermal decomposition of the selected Carpathian source rock was studied to determine the kinetic parameters of the pyrolysis process. The kinetic parameters of bulk rock and separated kerogen were determined using the model-free Kissinger, Kissinger–Akahira–Sunose (KAS), and Friedman methods. The pyrolysis process exhibits a complex reaction mechanism. The obtained apparent activation energy (Ea) and pre-exponential factor (A) values depend on the extent of conversion, suggesting that the process involves multiple reaction steps. This dependence is very similar when calculated using both isoconversional methods, Friedman and KAS; however, the calculated values of the kinetic parameters differ depending on the method used. It was found that the activation energy of kerogen is lower than that of bulk rock, and the reaction maximum was shifted to higher temperatures. This shift is attributed to the presence of clay minerals in the rock. The values of average activation energy and the pre-exponential factor found in this study are relatively high, possibly due to the nature of the short-chain organic matter contained in the source rock.