HYSYS and PSO Integrated Method for Mixed Oil Distillation Quality Control

In refined oil pipeline transportation, interface contamination generates mixed oil requiring reprocessing. This study focuses on addressing quality deficiencies in distilled gasoline derived from mixed oil. Comparative gas chromatography revealed severe losses of light hydrocarbons in gasoline: C5 content dropped from 14.37% in qualified gasoline to 0.45% (96.9% loss), and C6 decreased from 21.55% to 0.46% (97.9% loss), directly reducing octane number due to diminished contributions from these critical components. Toluene degradation further exacerbated the octane decline. To mitigate these issues, HYSYS simulation and Particle Swarm Optimization were employed to optimize distillation parameters, including a bottom column temperature of 200°C, bottom pressure of 20 kPa, and top pressure of 10 kPa. The optimization achieved the recovery of C5-C7 hydrocarbons aligning it with commercial specifications. The practical applicability of the optimized parameters was verified through field sampling combined with experimental testing. This approach significantly enhances the viability of mixed oil reprocessing while maintaining production stability.