Concentrations of volatile organic compounds (VOCs) at an oil refinery

This study measured and analysed individual volatile organic compounds (VOCs), total hydrocarbon and total VOCs at an oil refinery. Measurements were taken at various workplace locations, of the ambient air and at some off-site facilities such as its gantry terminals, ETP and tank farms. The study also identified certain pollutants that are difficult to measure routinely but could give an indication of their presence in a refinery. The VOCs were sampled using charcoal adsorption tubes and desorbed using a thermal desorption technique. The samples were subsequently analysed by Varian 2200 GC/MS system. The 8-h average concentrations of benzene, toluene, ethylbenzene and xylenes ranged between 23.48–113.05, 18.70–72.54, 2.91–9.80 and 5.83–27.64 μg/m3, respectively. Alongside substituted benzenes, such as 135 and 124, trimethylbenzenes and naphthalene were also detected. The total hydrocarbon ranged between 5.0–13.8 ppm and the NMHC was in the range of 2.2–9.0 ppm. The study indicates the concentration of fugitive emissions of VOCs in the refinery and its utilities