A NEW REACTION CONTROLLING THE COMPOSITION OF OILS: HYDROGENATION OF AROMATIC HYDROCARBONS

Analysis of the composition of n-alkyl-substituted monocyclic compounds of Tatarstan oils (n-alkylcyclohexanes, n-alkylcyclopentanes and n-alkylbenzenes) made it possible to prove that during the formation of the composition of the studied oils, hydrogenation reactions of aromatic hydrocarbons, previously not recorded in the rock, took place. It has been directly proven that n-alkylcyclohexanes of petroleums were partially formed from the n-alkylbenzenes present in them. At the same time, catalysts for the hydrogenation of aromatic hydrocarbons known from organic chemistry are either absent in any noticeable quantities in oils (and platinum group metals in the earth’s crust) or are inactive in natural environments. So today it is not possible to indicate a natural catalyst for this reaction. That is, the discovery of this reaction demonstrates the incompleteness of our understanding of the catalysts involved in the formation of the composition of oils. From the literature it follows that Tatarstan is not the only region in whose oils this reaction occurs. It has been shown that during hydrogenation, oils must be in conditions radically different from those that occurred during the formation of their main components (acid catalysts in the first stage and their absence in the second). It follows that the hydrogenation reaction of aromatic hydrocarbons in Tatarstan oils occurs at the later stages of their evolution, when the main composition of the oils has already been formed. It seems reasonable to assume that hydrogenation takes place after the migration of oil from the source rock. That is, this reaction occurs either along the oil migration routes or into deposits.