بحوث سكوبس — شهد عمار حاتم الزبيدي

This field study quantifies how reflux drum temperature governs the overhead risk posture of an atmospheric crude distillation unit during hot-season operation, with explicit attention to corrosion, flare loading, and economic loss. During a single summer campaign at Al-Diwaniyah Refinery, the drum temperature was stepped from 50 to 70 °C and, at each set point, off gas, light naphtha, and boot water were sampled under steady operation. Hotter drum operation reduced partial condenser driving force and shifted the overhead phase split toward vapor, increasing header pressure from 0.57 to 0.82 barg and standard off gas flows from 320 to 360 and from 35 to 50 Nm3/h to the furnace and the flare, respectively. Concomitantly, off gas became heavier: C1–C3 fraction contracted from 56.71 to 41.41 mol %, whereas C4 rose from 25.53 to 36.72 mol % and C5+ increased from 5.71 to 15.94 mol %. From a loss prevention perspective, this C4–C5+ enrichment, together with the higher flare rate, indicates increased diversion of gasoline-range material to the gas header and flare (avoidable hydrocarbon loss) and higher propensity for flare smoke if assist is not adjusted. Light naphtha specification drifted unfavorably (IBP from 32 to 40 °C; EP from 120 to 140 °C) with a modest increase in sulfur (from 300 to 312 ppm), tightening blending margins and risking reprocessing. Overhead corrosion risk increased, as boot water chemistry degraded (pH from 6.4 to 6.0; chloride from 10 to 14 ppm; dissolved iron from 0.15 to 0.44 ppm). These field resolved trends define a practical operating window that favors cooler drum targets (approximately 55–60 °C), recovery of condenser effectiveness, and temperature-compensated neutralizer control to stabilize aqueous chemistry while minimizing avoidable flaring. The results provide actionable guidance for balancing product quality, energy use, environmental performance, and corrosion risk in hot-climate refining. © 2026

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. © The Author(s), under exclusive licence to the Institute of Chemistry, Slovak Academy of Sciences 2025.