Corrosion and stress corrosion cracking in coal liquefaction processes

Corrosion by Polythionic Acid in the Oil and Gas Sector: A Brief Overview

“…PTA formation primarily occurs in refinery equipment through the reaction of O 2 and H 2 O with sulfide corrosion products that accumulate on the internal surfaces of the equipment (Figure 4). Moisture, often present from vessel washing or steaming during shutdowns, and oxygen from the air that enters when the vessel is opened contribute to the PTA formation process [37].…”

“…While the high operational temperature may cause sensitization of stainless steel (SS), the actual formation of PTA occurs when the material is exposed to air at ambient temperature during shutdown periods [37]. PTA can also be generated by the reaction of H 2 O and O 2 with oxidizable sulfur species during the combustion of H 2 S in refinery flares.…”