NON-ISOTHERMAL KINETICS OF THE PYROLYSIS OF WHOLE OIL AND ITS ASPHALTENE DERIVED FROM FOSTERTON OIL

Abstract

Coke formation from heavy oil has been extensively studied, and various kinetic models have been proposed in the literature. In this study, thermal behavior of crude oil and its asphaltene obtained from the Fosterton field was investigated using thermogravimetric analysis. Non-isothermal pyrolysis experiments of whole oil and its asphaltene were performed in nitrogen atmosphere at different heating rates of 5, 10, 15, and 20°C/min. Although much difference was observed in the weight loss profile for whole oil and its asphaltene, the final amount of coke formed changed with the heating rate. The non-isothermal pyrolysis kinetics of whole oil and its asphaltene was studied with the distributed activation energy model (DAEM). Non-isothermal experiments were better described by the DAEM compared to other applicable models. The activation energy for whole oil pyrolysis spread over a range of 7 to 129 kJ/mol, and the pre-exponential factor varied from 102 to 1011 min−1. The asphaltene fraction separated from the oil had activation energy between 50 and 183 kJ/mol, and the pre-exponential factor ranged from 107 to 1014 min−1. Results from the kinetic analysis show that asphaltene has higher activation energy than whole oil.