Composition of high-molecular-weight aromatic hydrocarbons of petroleum

Conclusions

• 1. A procedure is proposed for separate determination of alkylaromatic and naphthene-aromatic hydrocarbons (with benzene, naphthalene, phenanthrene, and pyrene rings) in the aromatic part of petroleum products, on the basis of mass and ultraviolet spectra.

• 2. We have demonstrated and explained the reason for the inadequate selectivity of chromatographic separation on silica gel. Hydrocarbons with a benzene ring, including alkylbenzenes, are present in all aromatic fractions from chromatographic separation. In the “light” fractions there are alkylbenzenes with a single long side chain; in the “heavy” fractions there are alkylbenzenes with several alkyl chains.

• 3. The naphthene-aromatichydrocarbons consist of benzene, naphthalene, and phenanthrene hydrocarbons condensed with one to six naphthene rings.

• 4. By thermal-diffusion separation of the aromatic part of petroleum products, we have obtained alkylaromatic hydrocarbons with a V.I. of 90 and naphthene-aromatic hydrocarbons with a V.I. of-180.

  Investigation of aromatic hydrocarbons on the basis of mass and ultraviolet spectra has made it possible to estimate the contents of both alkylaromatic and naphthene—aromatic hydrocarbons with various numbers of aromatic and naphthene rings.

  These data have made it possible to follow the course of aromatic hydrocarbon separation in thermal diffusion and on silica gel, and also to establish the content of alkylbenzene hydrocarbons in the high-molecular-weight fractions of petroleum.