Composition and structure of solid petroleum hydrocarbons which form urea complexes

Abstract

Analysis of the chemical composition of the solid petroleum hydrocarbons which form urea complexes shows that they compose a group of hydrocarbons of varied chemical structure (normal alkanes and isoalkanes, alkylcyclanes and alkylarenes) which have as a mandatory structural element a long unbranched alkyl chain. The chemical composition of solid hydrocarbon fractions isolated from petroleum with urea depends on the nature of the petroleum and the character of the feedstock fraction (low-boiling or high-boiling distillates or residues from distillation). A feature of the molecular structure of the solid saturated petroleum hydrocarbons which form urea complexes — the presence of a long unbranched alkyl chain in conjunction with general low branchedness of isoalkane or alkylcyclane molecules—determines the commonness of various properties and phase behavior of the fractions being studied, which makes this group of hydrocarbons close in many ways to normal alkanes. The principles given present interest in consideration of distillate paraffins composed predominantly of complex-forming hydrocarbons.