CFD simulation for dispersion of benzene at a petroleum refinery in diverse atmospheric conditions.

Atmospheric parameters play a vital role in the dispersion of air pollutants. Benzene is a confirmed human carcinogen. It is also a neurotoxin and an irritant compound. The objective of this study was to examine the CFD simulation by Fluent16 software to simulate and analyze the effect of atmospheric conditions on the dispersion of benzene in eight different scenarios in a petroleum refinery. According to the results of this study, the highest and lowest impacts of atmospheric parameters occurred on spring days and autumn nights, respectively. Wind direction did not have a significant effect on the benzene distribution due to the artificial ceiling of piping installations in the computational domain. However, the wind speed had a critical role in the benzene dispersion. The maximum concentration occurred at 36- to 37-m distance from the inlet boundary for all scenarios except winter nights. On winter nights, this distance increased to 38 m. Benzene concentrations were the highest at their sources of release. They decreased after the artificial ceiling of the pipelines was at 5.5- to 7-m height where the air displacement was not sufficient, and therefore, leading to a gradual reduction in concentration. The accumulation of benzene concentration in the small domain was noticeable compared to the benzene concentration distributed in the total computational domain, and the authors recommended control measures in this domain. This study demonstrated CFD simulation methodology could enable the investigators to predict the benzene concentration dispersion in the atmosphere of a petroleum refinery plant. These findings can be used by occupational health engineers for health risk assessment of refinery personnel involved with maintenance operations and engineering control systems.