Exploring pyrolysis of the aromatics in shale oil by experimental study and kinetic modelling

Abstract

In this work, the main aromatics in shale oil from retorting Huadian oil shale and the functional groups during the pyrolysis of shale oil were studied experimentally. The aromatics in shale oil are mainly monocyclic aromatic hydrocarbons (MAHs). Alkylbenzenes are the most abundant in MAHs of shale oil. Then, nonylbenzene was selected as representative to explore the pyrolysis mechanism through theoretical calculation and kinetic modelling due to the activity of its alkyl side-chain and the abundance in alkylbenzenes of shale oil. The bond dissociation energies (BDE) of the C–C and C–H bonds were calculated using the CBS-QB3 quantum chemistry method to study its thermostability. Finally, the detailed pyrolysis kinetic mechanism of nonylbenzene was written by the GRI-Mech3.0 mechanism. A large number of the kinetic parameters were computed by the group-additivity method. In addition, the kinetic parameters of these two non-negligible retroene reactions of nonylbenzene were calculated by the CBS-QB3 method to develop the kinetic model. In summary, the pyrolysis mechanism can improve the understanding of shale oil reactivity due to that it could be chosen as a model compound for novel surrogate shale oil model and has a significant guidance on the development of the kinetic model of alkylbenzenes.