Hydroconverted bottoms (HCB) from a commercial LC-Finer are highly aromatic and contain smaller more aromatic asphaltenes relative to virgin bitumen. In the HCB, these asphaltenes are near their limit of stability and can become problematic for further processing or for utilizing the bottoms as a feedstock in other applications. The stability of these bottoms can be selectively improved by treating them by adsorption. By using the asphaltene solubility profile—provided by the Asphaltene Determinator (AD) analysis—it was shown that the most polar aromatic asphaltenic fraction is selectively removed. Certain parameters of the adsorption process were optimized, such as contact time and temperature, for a specific silica sorbent. Adsorption results for a series of different silica sorbents indicated optimum sorbent properties. Optimum sorbent properties for the HCB were significantly different compared virgin bitumen. Experiments were conducted showing the effect of particle size on adsorption saturation and pore plugging. The treated oils exhibited enhanced thermal stability with respect to the AD Coke Index. Additional analysis of the treated HCB showed a decrease in its viscosity, decreased aromaticity, decreased TBN and nitrogen content, decreased Ni and V content, and improved stability according to asphaltene flocculation. Solvent desorption was successfully employed to regenerate the sorbent, and additional adsorption experiments conducted using the regenerated sorbent demonstrate how the sorbent can be recycled for additional adsorption sequences.

Selective asphaltene adsorption from hydroconverted bottoms

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.