Hydrogen Sulfide Reactor Vessel Nace MR0175/ISO 15156. Section VIII, Div. 1 Or 2 API 650/620

Nace MR0175/ISO 15156. Section VIII, Div. 1 or 2 API 650/620

Hydrogen sulfide (H₂S) reactor is a specialized vessel designed to process, remove, or convert H₂S—a toxic, corrosive, and flammable gas commonly found in natural gas, refinery streams, biogas, and chemical processes. These reactors are crucial in gas sweetening, sulfur recovery (Claus process), and wastewater treatment.

Below is a detailed breakdown of the composition and key components of an H₂S reactor:

• Stainless steel (316L, 2205 duplex) – Resists H₂S-induced stress corrosion cracking (SSC).
• Nickel alloys (Inconel 625, Hastelloy C-276) – For high-temperature/pressure applications.
• Carbon steel with internal lining (e.g., glass-reinforced epoxy (GRE), rubber lining) for cost-effective solutions.

• NACE MR0175/ISO 15156 (for H₂S service).

• Cylindrical, vertical/horizontal orientation.
• Pressure rating: Typically 5–100 bar, depending on process (e.g., Claus reactors operate at ~1–5 bar).
• Temperature range: 50–600°C (Claus reactors run at ~200–350°C).

Since H₂S causes sulfide stress cracking (SSC) and hydrogen-induced cracking (HIC), these standards dictate material selection:

• NACE MR0175 / ISO 15156
• Defines acceptable materials for sour service (H₂S-containing environments).
• Requires:
• Hardness limits (e.g., ≤ 22 HRC for carbon steel).
• Sulfur content control in steels.
• NACE TM0284 (HIC Testing)
• Evaluates resistance to hydrogen blistering in steels.
• NACE TM0177 (SSC Testing)
• Tests materials under tensile stress in H₂S environments.