Changes in the Composition of Residual Fractions and Structure of Asphaltene Molecules during Atmospheric-Vacuum Distillation of Heavy Oil
D. S. KORNEEV1,2, G. S. PEVNEVA1, A. K. GOLOVKO1,2
1Institute of Petroleum Chemistry Siberian Branch Russian Academy of Sciences, Tomsk, Russia 2Institute of Petroleum Geology and Geophysics Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: тяжелая нефть, первичная переработка, перегонка, мазут, гудрон, нефтяные остатки, асфальтены, состав, структура, heavy crude oil, primary processing, distillation, fuel oil, tar, oil residues, asphaltenes, composition, structure
Pages: 439-444
Abstract
The changes in the composition of the residual fractions and the structure of the asphaltene molecules during the primary processing of heavy oil are investigated. It was established that the atmospheric-vacuum distillation of heavy oil is accompanied by the formation of additional resin-asphaltene substances (more than 20 mass %). The initiation of chemical reactions between oil components occurs at the stage of fuel oil production due to the destruction of mainly sulphur-containing fragments in asphaltene molecules. It was shown that during tar production, the destruction and elimination of asphaltene-saturated fragments occur with a decrease in the content of naphthenic and paraffinic carbon by 5.5 and 1.7 %, respectively. Recombination reactions between the resulting macroradicals of asphaltene molecules contribute to an increase in their aromaticity factor by 7.2 % and the average molecular mass by 190 Da. Collection of the fraction 350-450 °C leads to a decrease in the average molecular mass of asphaltenes by 425 Da with an insignificant redistribution of carbon in various structural fragments.
DOI: 10.15372/CSD2019163
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