СОСТАВ И СТРУКТУРА СМОЛИСТЫХ КОМПОНЕНТОВ ЛЕГКОЙ И ТЯЖЕЛЫХ НЕФТЕЙ

Abstract

The relevance of the work is caused by the need to gather and summarize the information on composition and structure of resin components of oils of different chemical nature, since the structural characteristics of resins have a significant impact on the level of their conversion to light hydrocarbons used for production of light oil products. In recent times, the researches in this direction have taken a particular importance due to the steady growth of heavy high viscosity oils in explored and recoverable reserves. Heavy high viscosity oils differ from conventional oils in a high content of high molecular weight heteroatomic compounds. The aim of the study is the comparative study of composition, structure and structural features of the main structural units of the molecules and chemical composition of the organic nitrogen bases of the resinous components of light and heavy oils. Methods: elemental analysis, cryoscopy in benzene, liquid adsorption chromatography, selective chemical destruction of sulfide and ether bonds, 1H NMR spectroscopy, structural-group analysis, gas chromatography-mass spectrometry.Results. The authors have carried out a comparative analysis of composition and structure of the resin components of the light oil and those of heavy oils and determined the similarities and differences of their structural-group composition and the composition of nitrogen-organic bases and fragments bound in the molecules of resins through ether and sulfide bridges. It was shown that resins of heavy oils are distinguished by large overall sizes of mean molecules due to the number of structural blocks bound together (1,79–1,86 againist 1,25). These structural blocks have larger average sizes of polyarene cores (2,36–2,43 againist 1,57), a greater number of alicyclic fragments condensed with an aromatic core of the molecules (4,56–4,75 againist 3,42), and an abundance of long alkyl substituents (2,42–2,59 againist 1,97). The most common «bound» fragments of macromolecules of the resins under study include n-alkanes, cyclohexanes, pregnanes, cholestanes, heylantanes, and hopanes. The peculiarity of resin molecules of heavy oils is the presence of polycyclic aromatic hydrocarbons and hetero-organic compounds in their «ether-bound» fragments, while resins of the light oil are characterized by the presence of polycycloalkanes, ethyl esters of n-alkanoic acids, aliphatic alcohols and bicyclic sulfides in their compositions. Resins of heavy oils are characterized by a higher total yield in organo-nitrogen bases (38,4–40,8 againist 26,0 %), where the prevalence of compounds precipitated as insoluble hydrochloride salts was revealed (36,5–37,6 againist 10,9 %).