Abstract
Phenanthrene, anthracene and pyrene have been pyrolysed in sealed reactors in the presence of coal. No methylation occurs at 220°C but increasing amounts of methylaromatics are formed at temperatures to 350 or 400°C. This methylation provides support for geosynthetic processes in sediments, because the experimental conditions used may be thermally equated to Ro values of 0.63-2.03%. The high concentration of n-alkanes generated from the coal may play a crucial role in such reactions. With increasing temperature there are systematic and theoretically predictable increases in the ratio of the β/α substituted methyl isomers of the parent aromatic hydrocarbons. The greater proportions of β-substituted isomers in the methyl products of reactions at higher temperatures may be due either to α→β rearrangements, or to direct methylation at the β-positions. Yields of methylphenanthrenes continue to increase up to 400°C. Lower yields of methylanthracenes and methylpyrenes at 400°C are attributed to demethylation.
Original language | English |
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Pages (from-to) | 71-80 |
Number of pages | 10 |
Journal | Organic Geochemistry |
Volume | 23 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1995 |
Keywords
- alkylaromatics
- aromatic hydrocarbons
- artificial maturation
- methylanthracenes
- methylation
- methylphenanthrenes
- methylpyrenes
- pyrolysis