5-Step Corrosion Inhibitor Selection for Refinery Units
Benxin Technical Team · 2025
Selecting the right corrosion inhibitor is a systematic process — it cannot rely on price alone or past experience. The following five-step methodology applies to most petroleum refinery units:
1
Identify corrosive species: Analyse concentrations and partial pressures of H₂S, HCl, CO₂, and organic acids in your unit. Determine the dominant corrosion mechanism — acid attack, chloride corrosion, or CO₂ corrosion.
2
Confirm operating temperature: Ambient to 150°C → water-soluble or oil-soluble imidazoline; 150–300°C → dedicated high-temperature inhibitor required; >300°C → combine with metallurgical upgrade.
3
Determine phase at injection point: Aqueous phase present → water-soluble type (BXH-101); pure oil phase → oil-soluble type (BXH-102/105); two-phase coexistence → composite formulation required.
4
Assess environmental compliance: Check your industrial park's phosphorus and nitrogen discharge standards. Where requirements are strict, prioritize phosphorus-free formulations (BXH-103).
5
Validate on-site: Any new inhibitor should first undergo a ≥72-hour coupon immersion test, comparing corrosion inhibition efficiency and compatibility with existing chemicals. Scale up only after data confirms performance.