Volume 25 , Issue 1 , June 2023 , Pages 148-164
Gashaw L. Abdalla 1 ; Abdulsalam R. Karim 1 ; Luqman Omar Hamasalh 1
1 Department of Chemistry, College of Science, University of Sulaimani, Sulaimani City, Kurdistan Region, Iraq.
For vast decision-making during the production process, knowing the physicochemical
properties of petroleum and petroleum fractions is of major significance. Different types
of crude oils from the Kurdistan Region and Iraq, namely (S for Sarqalla, K for Kirkuk,
and B for Bardarash), have been compared, evaluated, and physicochemically
characterized. American Society for Testing and Materials (ASTM), Universal Oil
Production (UOP), and Institute of Petroleum (IP) standard test methods were used to
estimate (density (Kg/m3
), API gravity, viscosity (cSt), salt content (ppm), H2S content
(ppm), flash point (
oC), pour point (
oC), sulphur (wt%), Reid vapor pressure (psi),
asphaltene (wt%), and ash content (wt%)) to know the complexity of crude oils. Crude
oils were fractionated into fractions based on their true boiling point via carbon
distribution, including the paraffin, naphthenic, and aromatic (PNA) composition of their
fractions through the refractive index-density-Molecular weight (n-d-M) method using a
standard test method of ASTM D 3238, as well as the determination of metal elements
in crude oils by inductively coupled plasma optical emission spectroscopy (ICP-OES).
Afterward, Fourier transform infrared (FT-IR) spectroscopy was used for the
characterization of precipitated asphaltene in crude oils and their residues (+270 oC). It
was found that they have very similar chemical structures.