H2s Corrosion and Scaling In Gas Removal System – A Failure Analysis Update and Mitigation In Wayang Windu Geothermal Power Plant

A hybrid Gas Removal System (GRS) or gas exhauster runs to extract non-condensable gas (NCG) from the Turbine Condenser in a single flash geothermal system in Wayang Windu Geothermal Power Plant. Some repetitive failures were reported on the condenser vessels in GRS presumably due to cracking related to internal corrosion and scaling. Scale product characterization by X-ray spectroscopy and operational monitoring program confirmed the previous presumption of the cracking due to H2S corrosion. Having found the root cause, a set of mitigation programs was developed, including mechanical design improvement by fracture toughness-based thickness calculation, material specification upgrade, and an enhancement of the operational procedure and monitoring. The implemented mitigation is shared to encourage proper equipment design and operation in a geothermal environment, avoiding the risk of plant downtime due to similar failure