Characteristics of High-Molecular-Weight Components Obtained by Thermal Destruction of Oil Residue Asphaltenes in Supercritical Water

The composition and characteristics of high-molecular-weight components of the thermolysis products of petroleum residue asphaltenes obtained in supercritical water with and without a catalyst based on iron oxides have been studied. The experiments were carried out in an autoclave at a temperature of 450°C for 60 min; the catalyst was prepared in situ from iron(III) tris(acetylacetonate). The use of supercritical water and the in situ prepared catalyst made it possible to increase the yield of saturated and aromatic hydrocarbons by a factor of more than 9.5 compared to that in a control experiment (thermolysis without water and a catalyst) and decrease the yield of solid products insoluble in chloroform. The properties of high-molecular-weight components isolated from the thermolysis products were characterized using structural group analysis and IR spectroscopy. High-molecular-weight components obtained by thermolysis in supercritical water in the presence of the catalyst, in comparison with the products obtained in the control experiment, were characterized by higher H/C ratios and concentrations of oxygen-containing groups and lower average molecular weights.