Preventing corrosion and tube failure in sulfur condenser during normal operation, startup, and shutdown of the south pars gas processing plant (case study)

•Pore study on various kind of corrosion that occurred in SRU.•S(elemental) is formed during shutdown and makes corrosive environment in overhaul.•We found sulfuric acid can compose in catalytic bed during startup.

In each sour gas processing plant, the sulfur recovery unit is one of the most important processes regarding environmental aspects, since improper performance of this unit can impose critical problems on the environment. Gas containing H2S is sent to a sulfur recovery unit to recover the sulfur and avoid venting H2S to the atmosphere. Corrosion is a major concern in the sulfur recovery process due to the presence of a high percentage of hydrogen sulfide, as well as high temperatures in most of the unit's equipment. The leaking tubes were found in the bottom of the low-pressure steam condenser. A set of operational parameters such as H2S, CO2, and hydrocarbon concentration, reaction furnace temperature, process configuration, cold or hot bypass need to demonstrate the cause of the corrosion issues encountered in the sulfur recovery condenser. The main objective of this paper is to thoroughly investigation about root cause analysis of corrosion problem that is occur in sulfur recovery from a gas processing plant located in south of Iran. Moreover, it will propose protective actions to avoid reoccurrence of corrosion problems. This paper will review potential corrosion mechanisms and operational data which illustrate the importance of warm up and cool down during startup and shutdown procedure and also bad operation.