Composition and structure of products of thermal degradation of asphaltenes in heavy crude oil

Abstract

The data are presented on changes in the structure of asphaltenes in the heavy oil sample from the Usinskoye oil field during their thermal transformation at 300 and 450°C and in fragments bound in their molecules via ether and sulfide bridges. It is shown that the “secondary” asphaltenes are characterized by lower molecular masses and smaller sizes of mean molecules and differ in the composition of “sulfur-bound” and “ester-bound” structural fragments. The increase in the process temperature results in a wider set of compounds in the products of the C–O bond cleavage and a narrower set of compounds in the products of the C–S bond cleavage.