(395b) The Investigation of the Effects of Asphaltene Molecular Properties on Asphaltene-Solids Heterogeneous Interaction

Asphaltenes are a class of large aromatic organic compounds in crude oil that are soluble in aromatic hydrocarbons like toluene but insoluble in n-alkanes like n-heptane. Asphaltenes are a high polydispersity system diverse in an aliphatic chain(s), aromatic core size, and heteroatom(s). Some oils may contain varying concentrations of inorganic solids depending on the source locations. Small solids (< 1 micron) are difficult to remove during gravimetric and centrifugal separations are commonly performed to extract bitumen from oil sands. Inorganic solids presenting crude oil promote asphaltenes precipitation rate. Moreover, the insoluble asphaltenes assist in bridging inorganic solids into large flocs However, it is not well-understood which type of asphaltenes and why they interact with solids. The primary objective of this research is to correlate the asphaltene molecular structures to the interactions with solids during the asphaltene phase transition and investigate the mechanism of heterogeneous interaction. We hypothesize that the asphaltene-solid heterogeneous interaction is a multi-component phase transition process, and solids presenting might impact asphaltene thermodynamic properties. Asphaltenes will be fractionated based on whether they participated in heterogeneous interaction and then characterized their molecular properties, including double bond equivalent (DBE), heteroatom content, and molecular weight (carbon number). We plan to apply Fourier Transform Ion Cyclotron Resonance (FT-ICR) Mass Spectrometry (MS) with a 9.4 Tesla magnetic field to characterize asphaltenes molecular features. We will use principal component analysis (PCA) to correlate the molecular features promoting asphaltene-solid heterogeneous interaction. The cumulative knowledge compiled through the high-resolution mass spectrometry, scattering experiments, and principal component analysis should provide better insight into the driving force of asphaltene-solid heterogeneous interaction.