DSC study on combustion and pyrolysis behaviors of Turkish crude oils

This study focused on the investigation of non-isothermal thermal behavior and kinetics of Turkish crude oils under combustion and pyrolysis conditions using differential scanning calorimetry (DSC). On DSC combustion curves, two exothermic oxidation regions were detected known as low temperature (LTO) and high temperature oxidation (HTO). Again, two distinct reaction regions were revealed under pyrolysis conditions and DSC curves exhibited endothermic behavior for both the distillation and cracking regions. In consequence of thermal analyses, the heat of reaction amount was related to the °API gravity and accordingly to the asphaltene content of crude oils. It was proved that, with the decrease in °API gravity of crude oil, its heat release during HTO and heat requirement for cracking reaction increase. Experimental results showed that the reaction temperature intervals, peak temperatures and heat flows shifted to greater degrees for higher heating rates. With the application of ASTM I–II and Roger & Morris kinetic methods, it was observed that heavier oils with higher asphaltene content had greater activation energy and Arrhenius constant values.