ABSTRACT
Crude oil is a complex liquid mixture containing hydrocarbons and various heteroatoms. is refined through fractional distillation to produce a range of products, including Premium Motor Spirit (PMS). The quality of PMS is critical for ensuring engine perfo rmance and efficiency, with specific parameters such as viscosity, specific gravity, boiling point, and pour point being vital indicators. The study evaluated the physicochemical properties of PMS samples collected from five licensed retail outlets in Benin City, Nigeria, to assess their compliance with industry standards. Five PMS samples were collected from UBTH Filling Station, Total Energies, Zomisk Oil and Gas, Hensmor Oil, and Conoil. The samples were stored in labeled, air-tight containers and analyzed for specific gravity, viscosity, boiling point, pour point, and cloud point. Standard laboratory procedures were followed, with all reagents being of analytical grade. The data were compared against ASTM and NNPC specifications for PMS quality. The analysis revealed significant variations in the viscosity of the samples, with Sample A exhibiting the highest viscosity (3.96), far exceeding the ASTM standard range of 0.2 to 0.8. Specific gravity values were within the acceptable range, except for Sample A, which showed a slight deviation. All samples conformed to the standard boiling point range. Pour point results indicated good coldweather performance, with Sample B performing best at -20.7°C. The observed deviations suggest potential concerns in blending and refining processes. The PMS samples from Benin City exhibited moderate adherence to quality standards, with notable deviations in viscosity, particularly for Sample A. These inconsistencies bring to light, the need for improved refining practices and better regulatory oversight to ensure product quality. Additional analysis such as sulfur content and octane rating, is equally important for a comprehensive assessment of PMS quality.
