Evaluation the Asphaltene Content in Various Types of Iraqi Crude Oil Using Fluorescence Spectroscopy
Year: 2026
Type: article
Abstract: The effect of asphaltene fractions on the physical and optical properties of four Iraqi crude oils (Basrah, Al-Ahdab, Kirkuk and Khanna) was evaluated using a simple and sensitive procedure. The crude oil samples were separated into asphaltene fractions using n-pentane and the corresponding de-asphaltened oils were analyzed. Cross-plots of viscosity, specific gravity and fluorescence emission intensity were generated using an excitation wavelength of 350 nm for the original crude oils and their de-asphaltened fractions. The asphaltene content of the samples was quite different, ranging from 22 wt% in Al- Ahdab and 20 wt% in Basrah to 15 wt% in Kirkuk and 8 wt% in Khanna. The removal of the asphaltene fraction resulted in a significant viscosity decrease (25–30%) and specific gravity (0.02–0.04 units) and a distinct increase in fluorescence emission intensity. The effects were more significant in Basrah, Al-Ahdab and Kirkuk crude oils, whereas Khanna crude oil exhibited only slight changes due to its relatively low asphaltene content. The results reveal the influence of asphaltene fractions on the physical behavior of crude oil and demonstrate the usefulness of fluorescence spectroscopy as a rapid technique for detection of compositional variations in petroleum systems.
Source: Iraqi Geological Journal
Institution: Scientific Research Commission
Language: English
Subfield: Analytical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $175
OpenAlex ID: W7204804379