Optimizing naphtha blending at Al-Diwaniyah refinery for enhanced gasoline production: improving octane number and minimizing sulfur content

The Al-Diwaniyah refinery conducts this study to investigate the effects of blending light and heavy naphtha on the octane number and sulfur content of mixed naphtha, a critical intermediate in gasoline production. Using the Box–Behnken design in Minitab, the study carefully looks at how operational variables like top temperature (110–125 °C), flow rate (1–4 m³/hr.), and pressure (0.6–1 bar-g) affect the quality of the fuel. Minitab was used for accurate statistical modeling, which showed that the best conditions for blending produce an octane number of 51.43 and a sulfur content of 343.66 ppm. These conditions are equivalent to a heavy naphtha flow rate of 1 m³/hr, a top temperature of 110 °C, and a pressure of 0.6 bar-g, which improves engine performance and lowers the impact on the environment. To validate these findings, the blending process was simulated using Aspen Hysys, a powerful tool for process modeling in the petroleum industry. The simulation results aligned with the actual data, and a comprehensive relative error analysis revealed slight variances in octane numbers and more significant variations in sulfur content. This analysis underscores the simulation’s reliability in forecasting octane numbers while pinpointing opportunities for enhancement in sulfur content prediction.