Study of the influence of aromatic hydrocarbons on the process of tar oxidation

Abstract This study examines the impact of polycyclic aromatic hydrocarbons on the oxidation of petroleum tar. An aromatic hydrocarbon concentrates isolated from extracts of selective oil purification using the polar industrial solvent N-methylpyrrolidone was employed as an additive to tar. The relationship between the softening temperature of oxidized bitumen and both the duration of oxidation and the properties of the initial raw material mixture was investigated. It has been established that the introduction of 10 wt.% aromatic additive will increase the oxidation rate by 6 °C/h. The conditions for producing road bitumen from the proposed raw material compositions were identified. The influence of polycyclic aromatic hydrocarbon concentrate on the qualitative characteristics of bitumen during the tar oxidation process was determined. Aromatic additive is similar to a plasticizer, and reduces the softening temperature of bitumen by 9 °C. But the combined oxidation of tar with an aromatic additive and a catalyst makes it possible to obtain bitumen with a softening point of 44 °C and a penetration of 80 x0.1 mm, which corresponds to the grade of bitumen 70/100. Analysis of the group composition of oxidized bitumen revealed that the aromatic additive facilitates the intensification of the tar oxidation process.