Kinetic study on the nonisothermal pyrolysis of oil sand bitumen and its maltene and asphaltene fractions

Abstract

Pyrolysis is an important conversion process which can produce high value-added light oils from unconventional oils such as oil sand bitumen and extra heavy oil, thus it is important to understand the characteristics and kinetics of pyrolysis for unconventional oils. In this study, the nonisothermal pyrolysis of Athabasca oil sand bitumen and its maltene and asphaltene fractions was analyzed using a thermogravimetric analyzer, and activation energies for pyrolysis were determined by the model-free isoconversional Friedman analysis. The analysis suggests that the pyrolysis of oil sand bitumen consists of reactions for volatilization of maltene fraction and cracking of maltene and asphaltene fractions. The pyrolysis behavior of oil sand bitumen was well described based on the kinetic parameters estimated by the distributed activation energy model for maltene and asphaltene fractions, which is beneficial to effective utilization and development of pyrolysis processes of oil sand bitumen. (C) 2016 Elsevier B.V. All rights reserved.