Gas flaring is often a frequent occurrence in the oil and gas industry, where significant unrecovered residual gases is flared to the atmosphere with wide ranging negative environmental implications such as increased greenhouse, SOx emission and other deleterious pollutants that have negative health implications on local populations. Recent environmental awareness, drive to lower emission and economic benefits associated with flare gas recovery has however led to a paradigm shift in flaring practice. Establishing a robust flaring minimization program and committing to the World Bank “Zero Routine Flaring by 2030” initiative is therefore a crucial step towards achieving these goals.

One of the prominent flaring minimization technologies leveraged is the integration of Flare Gas Recovery Units (FGRU) in new gas plants. There are plethora of FGR technologies such as; caustic treatment, solid scavenging, liquid scavenging and membrane technologies. The final selection is determined by techno-economic factors, however, the most ubiquitous FGR technology consists of a compression system that is used to increase the pressure and an acid gas removal unit (AGR) using amines, that is used to remove the sour hydrogen sulfide (H2S) in the gas stream to achieve non-sour or “sweet” gas specifications suitable for use as a fuel gas in the plant The feed stream into the FGRUs are routed from across the plant, and therefore contains wide array of composition. Consequently, the nature of these stream alongside the multistage compression before entry into the AGR unit pose unique process and corrosion challenges in comparison to traditional sales gas AGR units. This paper will chronicles fundamental and process and corrosion issues encountered in FGRUs in a major operating gas plant.

The paper includes description of the process and material selection in the FGRU; types of damage mechanisms; corrosion monitoring & inspection alongside flow assurance issues encountered in the compression stage. The paper will also detail endeavors in the implementation of effective corrosion and integrity management. Specifically, highlights on how digitalization of corrosion mangment, utilizing realtime process parameters and integrity operating windows (IOWs) contributes to the FGRUs integrity will be discussed. The paper will also show Implementation of novel technologies to mitigate solid deposition in the compression stage.