Sour Service Without Greenwashing: Palm-Fatty-Acid Imidazolines, Persistent Corrosion Films and Evidence-Based Pipeline Integrity in CO2/H2S Systems

Abstract

Wet oil-and-gas pipelines exposed to carbon dioxide (CO2), hydrogen sulphide (H2S), produced water and fluctuating operating conditions require dependable control of both generalised corrosion and localised integrity threats. Palm-derived fatty acids are chemically plausible precursors for nitrogen-bearing imidazolines and amidoamines, but renewable provenance alone does not establish corrosion inhibition, film persistence or environmental superiority. This critical qualitative literature review interprets recent corrosion, oleochemical, surface-science and sustainability evidence without claiming exhaustive systematic retrieval. The synthesis distinguishes direct palm-based evidence from non-palm molecular analogues and separates initial electrochemical efficiency from pitting resistance, under-deposit access, dynamic washout, top-of-line exposure and hydrogen-related service limitations. Mechanistic findings identify variable roles for head-group chemistry, hydrophobic-tail structure, protonation, micellization, hydrolysis, corrosion products and phase partitioning in governing apparent efficacy. A six-gate Palm-Derived
Corrosion Inhibitor Qualification Framework is proposed, progressing from feedstock verification and molecular characterization through controlled bench, deposition, dynamic-flow and monitored field evidence, with environmental and safety checks at each level. The key recommendation is conditional development: chemically reproducible palm-based candidates merit comparative study, but no broad claim of sour-service pipeline integrity or green superiority is justified without application-specific testing, localized-damage monitoring and whole-formulation environmental assessment.