Home – Home – Jornals – Chemistry for Sustainable Development 2020 number 3

The ability of heavy oil asphaltenes and oil residues to generate low and high molecular weight components during thermolysis at 290 °C is assessed. It was established that the conversion of asphaltenes exceeds 99 mass %, regardless of the degree of their transformation during the rectification of heavy oil. Oil asphaltenes generate the maximal amount of resins (21.4 mass %). while fuel oil and tar asphaltenes generate 9.4 and 7.3 mass %, respectively. It was shown that thermal transformations of asphaltenes during the rectification of heavy oil lead to the removal of large structural fragments from their molecules, thereby reducing the ability of asphaltenes to generate resinous substances at 290 °C. At the same time, the molecular structure of asphaltenes is compacted, which leads to an increase in their tendency to form coke-like products. The yield of coke-like products of the low-temperature thermolysis of asphaltenes from oil, fuel oil and tar is 42.1, 54.4 and 58.1 mass %, respectively. It is established that the thermal transformations of asphaltenes in the process of heavy oil rectification do not have any significant effect on their ability to generate gas and liquid hydrocarbons during thermal degradation. The results of the study should be taken into account when developing new technologies for the primary processing of heavy crude oils and upgrading the existing ones.