Structural Transformations of Heavy Oil Asphaltenes in the Course of Heat Treatment (Communication 2)

Chemical degradation and chromatography–mass spectrometry methods were employed to identify resin components interlinked via ester, ether, and sulfide bridges. The resins were preliminarily isolated from liquid products prepared by thermolysis, at 300 and 450°C, of high-resin heavy oil asphaltenes from the Usinskoye oil field. Unlike the resins isolated at 300°C, their 450°C counterparts predominantly contained compounds that consisted of heteroatoms (i.e., S, N, and O). The particular distribution of bound moieties in the resin samples isolated at these thermolysis temperatures likely indicates that the Usinskoye field heavy oil asphaltenes consist of molecules that vary both in the type and location of ester, ether, and sulfide bridges.