Background and Objectives: Industrial processes are the major sources of environmental pollutants. Oil & gas processing are one of the industries which emitting several air pollution matters in to the atmosphere. The obtained results of CO₂ emission in one of the Gas Sweetening unit of Iranian south oil company based on the field and deskwork calculations is presented in this paper.
Materials and Methods: Fuel analysis method is the best method for CO₂ estimation from combustion sources. In this paper, CO₂ emission factor for gas sweetening plants is estimated based on this method.
Results: The obtained results showed that  total CO₂ emission in selected unit is about 922212/97 (kg/d) and CO₂ emissions for the separate parts of this unit are 579661/75, 12921/93 and 329629/29 for acid gas flare, gas flare and boilers respectively.
Conclusion: comparison between the separated parts of the studied units showed that emission of acid gas flare is higher than other sources (i.e about 63% of total CO₂ emission), and by using the EPA default CO₂ emission factors the CO₂ emitted 1/2 % lower than the actual emission in the mentioned unit.