Structural group characteristics of resins and asphaltenes of heavy oils and their atmospheric-vacuum distillation residues

Transformations of resins and asphaltenes of heavy oils of various chemical compositions during their primary processing are studied by the example of the oils sampled from the Usinsk (Komi Republic, Russia) and Zuunbayan (Mongolia) oil fields. The structural-group parameters of the molecules of resins and asphaltenes of the original oils and oil residues (fuel oils) obtained by atmospheric vacuum distillation with the withdrawal of IBP-350°C fractions were determined using the data on elemental composition, molecular weight, and data of 1H NMR spectroscopy. It is found out that the changes in the molecular structures occurring during the primary processing of oils depend on the chemical composition of the original oils.