1141 ISSN 0965-5441, Petroleum Chemistry, 2017, Vol. 57, No. 12, pp. 1141–1143. © Pleiades Publishing, Ltd., 2017. Original Russian Text © S.O. Ilyin, O.A. Pakhmanova, A.V. Kostyuk, S.V. Antonov, 2017, published in Neftekhimiya, 2017, Vol. 57, No. 6, pp. 763–765. Effect of the Asphaltene, Resin, and Wax Contents on the Physicochemical Properties and Quality Parameters of Crude Oils S. O. Ilyin*, O. A. Pakhmanova, A. V. Kostyuk, and S. V. Antonov Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russia *e-mail: s.o.ilyin@gmail.com Received November 10, 2017 Abstract⎯On the basis of published reference data on crude oils recovered from more than 300 Russian oil- fields, the effect of the concentrations of paraffin waxes, resins, and asphaltenes on oil properties has been analyzed. There are correlations between the oil density, viscosity and the resin content, whereas the amount of asphaltenes (along with resins) has a greater effect on the oil quality characteristics, such as sulfur content, coke and petroleum diesel yields. Crystallizable paraffins do not have a significant effect on the properties of the oils, the pour point of which does not depend explicitly on the composition. Keywords: crude oils, density, viscosity, asphaltenes, resins, paraffin waxes DOI: 10.1134/S0965544117060160 Asphaltenes, resins, and paraffin waxes are the most nonvolatile, heaviest, high-molecular-weight components of crude oil, affecting its quality and physicochemical properties. In this paper, we analyze reference data on Russian crude oils [1] with the aim of revealing the correlation between the concentration of these components and oil characteristics, such as density, viscosity, pour point, sulfur content, and yields of petroleum products. RESULTS AND DISCUSSION The high density of oils is due to the presence of resins and asphaltenes in their composition. It turned out that the density of oil is reasonably well correlated (with a determination coefficient of R 2 = 0.608) with the resin content even without taking into account other components (Fig. 1). At the same time, the cor- relation with the wax content or the asphaltene con- tent (without resins) was found to be weak (R 2 = 0.297 or 0.386, respectively). The explanation may be that there is a certain rela- tionship between the resin and asphaltene contents. In other words, consideration of resins can automatically include taking account of asphaltenes. According to the classical Yen model of asphaltene molecules and nanoaggregates, this may indeed be the case, since asphaltenes with resins co-form micelles [2]. In con- trast, the present-day Yen–Mullins model does not suggest that resins play part in the formation and sta- bilization of asphaltene nanoaggregates [3]. However, evidence for the existence of a relation between asphaltenes and resins, for example, is the known effect of resins on the aggregative stability of asphaltenes [4, 5]. A higher resin content in petroleum ensures a smaller relative error in determining their content and, hence, a better correlation. Fig. 1. Correlation of the density and the resin content of oils. ρ = 0.814 + 0.415 c r R 2 = 0.608 30 25 1.00 0.95 0.90 0.85 0.80 0.75 ρ, g/mL с r , % 0 20 10 15 5