The Rock-Eval Pyrolysis and Hydrocarbon Generation Kinetic of Four Coal Samples from Different Areas, China

Abstract

Rock-Eval pyrolysis and hydrocarbon generation kinetic are effective and extensive methods to evaluate source rock. In this study, we chose four coal samples from different areas in China including Fuxing, Guangyuan, Fushun and Taiyuanzu. The results show that Fushun has the highest hydrocarbon generation capacity (399-427mg/g), the lowest dominant activation energy (47Kcal/mol) and frequency factor (1.32*1012/s), which has the highest transformation ratio at different heating rates. It is easy to evaluate the hydrocarbon potential of Fushun. But Fuxing, Guangyuan and Taiyuanzu have different frequency factors and activation energies. In the multiple frequency factors (MFF) model, it is difficult to evaluate hydrocarbon potential by activation energies when frequency factors are different. This study evaluates hydrocarbon potential by comparing transformation ratio at universal and geological heating rate. This is because transformation ratio is a comprehensive result of frequency factor and activation energy. In addition, different heating rates affect the hydrocarbon generation rate of coal samples, the hydrocarbon generation rate is positive with heating rates. For example, the hydrocarbon generation rate of Fushun at 5, 25°C/min are 0.0013 and 0.0051 mg/g.s1. And the temperature difference (AT) of main hydrocarbon generation period heated at 3°C/my and 5, 15, 25°C/min are different, which are 21-52 and 53-99°C.