Fugitive volatile organic compound (VOC) emissions from the chemical facility in the Energy zones constitute a complex issue in Iran. This research aims to identify and manage the release of volatile organic compounds from equipment in the petrochemical industry and in particular the olefin unit, which is one of the most important processes in the petrochemical industry. To recognize the emission points of the VOCs, process equipment was periodically visited by infrared technology(IR)using a leak detection camera. The Leak Detection and Repair (LDAR)program was conducted according to US Environmental Protection Agency (EPA)protocols and method 21 of this protocol. The percentages of VOCs emission from process equipment such as heat exchangers, valves, compressors, pumps, and transmitters were 33%,25%,17%, 17%, and 8%, respectively. The total leakage and emission of VOCs from the studied olefin unit were calculated as 648 tons per year.
In addition to the VOCs emission, the concentration and distribution of nitrogen oxides were simulated by AERMOD software. According to the simulation, the annual mean concentration of this pollutant in the whole area of modeling is below the standard of the Iranian Environmental Protection Agency (40 μg/m3). Utilizing ArcGIS software (v.10.2), the IDW[1] interpolation method was used for zoning the emission of benzene and ethyl benzene pollutants in ambient air. Interpolation of annual mean pollutant concentrations showed that benzene concentration was higher than the environmental concentration at all unit levels, but it is lower than the standard permitted by the US National Institute of Occupational Safety and Health.
Implementing a comprehensive Leak Detection and Repair program in the petrochemical industry on a larger scale can certainly help reduce greenhouse gas emissions and protect the environment and the ozone layer.
[1] Inverse Distance Weighting (IDW)
