An insight into molecular weight distributions of asphaltene and asphalt using Gel Permeation Chromatography

Asphaltene and asphalte precipitations during production, transportation and processing of crude oil are one of the problems in the oil industry. The amount and characteristics of these precipitations depend on the type of solvent, oil-solvent ratio, time, pressure, temperature, etc. Measuring molecular weight dis-tributions of asphaltene and asphalt could be necessary to predict the phase behavior and prevent asphal-tene and asphalte depositions. Therefore, in this study, the molecular weight distributions of asphaltene and asphalt were studied. For this purpose, asphaltene and asphalt samples were prepared by adding dif-ferent ratios of precipitants such as n-pentane, n-hexane, and n-heptane in an Iranian crude oil using the IP-143 method. Then, we used Gel Permeation Chromatography to measure the molecular weight distri-butions of these samples. The obtained results indicate that asphaltene has more aggregation with higher molecular weight compared to asphalt. In addition, results show that the molecular weight distribution of asphaltene is generally wider than the molecular weight distribution of asphalt.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

The study investigated the molecular weight distributions of asphaltene and asphalt, finding that asphaltene has more aggregation at higher molecular weights compared to asphalt, and the molecular weight distribution of asphaltene is generally wider than that of asphalt.