Evaluation of CO, SO2 and NOx Emission Factors for Gas Flares in Oil and Gas Processing Plants

Document Type : Research Paper

Authors

1 Environmental Engineering Research Center, Faculty of Chemical Engineering, Sahand University of Technology, Tabriz, Iran.

2 Khoozestan Azad university science and research center, Ahvaz, Iran.

3 Jondi Shapoor medical university, Ahvaz, Iran.

Abstract

Emission factors technique is one of the simple and low cost methods for estimating pollution from air pollutant sources. However, emission factors of gas flare may have high uncertainty because in flares, especially under emergency conditions, flow rate of flaring gases as well as combustion efficiency are unknown. The aim of this paper is to evaluate SO2, NOx and CO emission factors in gas flares. For this purpose, emission factors were estimated using back calculation method based on modeling and pollutant emission measurement in ambient air in a selected flare in an Iranian oil and gas plant. SO2, NOx and CO average emission factors for selected flare are determined to be 0.037, 0.0168 and 1.07 MMBtu/lb, respectively, with uncertainty of 34.3, 36.3 and 27.5%, respectively. Comparison of calculated emission factors with United States Environmental Protection Agency (EPA) and Regional Association of Oil and Natural Gas Companies in Latin America and the Caribbean (ARPEL) emission factors showed that both emission factors have high uncertainty, especially for NOx and CO emission estimation. Therefore, it is necessary to study details of the influence of ambient conditions on combustion efficiency of flares as well as experimental simulation of actual flare to obtain more representative emission factors of flares.

Keywords


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