Airborne aromatic volatile organics in the vicinity of a refinery complex during operation and hot-standby modes

Airborne concentrations of aromatic volatile organics were measured inside a refinery complex and its vicinity in normal operation and stand-by mode, for which a naphtha plant had been semi-operated for two weeks for repairing the air pollution control devices. The monitoring program was conducted in five different regions: inside the naphtha plant, surroundings of the naphtha plant, inside the refinery complex, on the refinery fenceline, and in the neighborhood of the refinery. Total concentrations of volatile organics within the naphtha plant increased significantly in hot-standby mode due to fugitive emissions. The correlations between airborne concentrations inside the naphtha plant and those outside the refinery complex were not significant. Local traffic emissions, rather than refinery emissions, exhibited significant site-specific effects on ambient aromatic volatile organics. Characteristic ratios of various aromatic volatile organics also varied in different operation modes.