Short description of important scientific result: Features of composition history of heavy Ashaltchynsk crude oil (Tatarstan) in model hydrothermal catalytic system are studied. It is established that in water vapour in the presence of hematite, natural catalyst, containing iron oxide at temperatures 210 ºС, 250 ºС, 300 ºС, there are processes of destruction of high molecular weight components of heavy crude oil with new formation of light fractions, which impacts on change of its component, hydrocarbonic, fractional and structural-group composition and structural parameters of asphaltenes. X-ray powder diffraction revealed the general tendency of increase in aromaticity factor of asphaltenes associates and the distance between aromatic layers and polymethylene chain fragments while reducing the size of associates and numbers of aromatic layers in them with increasing of temperature of experiments in the reaction system.
G.P. Kayukova, A.T. Gubaidullin, S. M. Petrov, G.V. Romanov, N. N. Petrukhina