Assessment of diesel fuel quality

Diesel is an essential energy source in the transportation and industrial sectors worldwide; hence, the quality of this commodity is crucial. This study compares various fuel samples to understand the quality of the fuels in terms of sulphur content, density, surface tension, viscosity, and calorific value. The properties of diesel fuel samples from eight (8) Filling Stations (Marketing Companies (MC)) were examined and compared with GSA 141:2022 and ISO 8217:2017 standards. Fuel from two companies, MC-A and MC-G had slightly lower densities than the standard, indicative of a possible contamination with lower-density fuels such as kerosene. The surface tension of all samples, except one was within the standard range. The only sample with the lower than the standard value also displayed high sulphur content. Although all the fuel samples met the minimum requirement for calorific value, the viscosities of the fuels from three companies were slightly higher than the specified standard value which can potentially result in higher emissions. In the case of sulphur content, fuel samples from only three companies were in compliance with the maximum 50 ppm standard. This means 62.5 % of the diesel fuel within the study area at the time contained more than the acceptable amount of sulphur. The findings in this research highlight the need to re-examine the quality of fuels along the distribution chain.