Products of thermal degradation of asphaltenes of heavy oil from the Ashalchinskoye oilfield in supercritical hexane

The results of studies of asphaltenes of bituminous oil from the Ashalchinskoye oilfield and oil and resin-asphaltene components isolated from the liquid products of their conversion in n-hexane under supercritical conditions are presented. It is found out that the mean molecules of secondary asphaltenes and resins differ from those of asphaltenes of the initial sample by the number of structural blocks. They prevail in the mean molecule of secondary asphaltenes, while in the mean molecule of resins they are lesser in number. A feature of the structural blocks of secondary asphaltenes is a lower number of naphthenic cycles, a higher content of sulfur atoms, and a reduced content of nitrogen and oxygen atoms. The structural blocks of the resulted resins consist of minority of aromatic and naphthenic cycles and contain a lesser number of sulfur and nitrogen atoms but more of oxygen atoms than the initial and secondary asphaltenes. The qualitative composition of the compounds identified in the resulted oils is substantially identical to that of the compounds identified in oil components isolated from liquid products of autoclave thermal degradation of asphaltene substances of heavy oils.