The major sources of gas flaring and air contamination in the natural gas processing plants: A case study

•The sources of gas flaring in four domestic gas processing plants have been identified.•The fuel gas consumption was adjusted after flare network back pressure calculation.•A modification design was made to solve the excessive fuel gas network corrosion.•The debris build-up was solved by means of injections of a chemical de-emulsifier.

Global flaring and venting of natural gas is a significant source of greenhouse gas emissions and airborne pollutants that has proven difficult to mitigate. Devastating impact of such emissions both on the climate and environment makes it inevitable for researchers, environmentalists and policy makers to give remarkable focuses on this issue in recent times. This paper revolves around highlighting potential and critical situations, identifying the proper mitigation and focusing on the sources of flaring and contamination to reduce the generation of wastes from the gas processing plants of a domestic natural gas field in Iran. The flaring management of four domestic gas processing plants with the total capacity of 252 million cubic meter natural gas in a day plays an important role in the environmental pollution reduction. The inventory of emissions lists all the individual sources of air contamination in each gas processing plant and the quantities of the emissions. The major sources of gas flaring are the regeneration gas coming from the mercaptan removal unit in Phase 1, the sweeping gas consumption in the flare network in Phase 2 and 3, and the backup stabilization gas flaring in Phases 4 and 5. The adjustment of fuel gas consumption was conducted after the flare network back pressure has been calculated in Phase 2 and 3 by a Flare Net simulator. In order to address the excessive fuel gas network corrosion in Phases 6, 7 and 8, a modification was performed in this gas processing plant. Chemical de-emulsifier injection allowed for removing the debris build-up on the rebuilder's tubes of the condensate stabilization column in Phases 4 and 5. The recycling regeneration gas of the mercaptan removal unit in Phase 1 reduced 55% of the gas flaring in this gas processing plant.