Generation of adamantanes and diamantanes by thermal cracking of polar components of crude oils of different genotypes

The thermal cracking of polar petroleum compounds—resins and asphaltenes—isolated from crude oils of different genotypes was carried out, with C₁₀-C₁₃ adamantanes and C₁₄-C₁₆ diamantanes being produced as a result. It was assumed that resins and asphaltenes contain the adamantane and diamantane moieties in their molecular structure. An explicit relation between the distribution of C₁₀–C₁₃ adamantanes in crude oils, thermal cracking products of high-molecular-mass (bp >350°C) saturated fractions, and the products of thermal cracking of resins and asphaltenes was revealed. The distributions of C₁₄–C₁₆ diamantanes in the cracking products of resins and asphaltenes are close to one another and correlate well with their distribution in the products of thermal cracking of high-molecular-mass (>350°C) saturated fractions, but differ from the distribution in oils. The products of thermal cracking of resins and asphaltenes almost completely lack cyclic hydrocarbons and contain only a small amount of remaining n-alkanes and isoprenanes.