High temperature transformation of tar-asphaltene components of oil sand bitumen

Abstract

Transformations of high-molecular-weight compounds of oil sand natural bitumen under the heat treatment are studied. For that purpose natural bitumen isolated from oil sand taken from the Beke field (Kazakhstan) was used as a substrate. Thermal processing of natural bitumen leads to a general change in the chemical composition of components and an increase in the output of certain factions. The contents of oil, tar and asphaltenes were determined and the elemental composition of tar-asphaltene compounds was evaluated. Molecular structures of the tar and asphaltene components of natural bitumen before and after cracking have been defined from the data of elemental analysis, NMR spectroscopy and molecular weight. The high molecular compounds were presented as giant molecules containing small aromatic islands with some linked by aliphatic chains, which proved by infrared spectroscopy.