Thermal Degradation of Corrosion Inhibitors in Oil and Gas Refining Conditions: Mechanisms, Consequences, and Strategies for Deposit Minimization

This article addresses the problem of chemical deposit formation in oil and gas refining equipment, with particular focus on the role of nitrogen-containing (amine-based) corrosion inhibitors—widely used to protect metallic surfaces of pipelines and process units—which, under high-temperature conditions, can themselves contribute to deposit formation. The paper presents a review of the scientific literature on the thermal stability of corrosion inhibitors, with a focus on nitrogen-containing (amine-based) compounds, and addresses the issue of deposit formation in oil and gas refining process equipment. The paper covers the classification of corrosion inhibitors and their mechanisms of action, the influence of metal surfaces on protection efficiency, and the underlying causes of deposit formation. Particular attention is given to the thermal degradation of amines, their interaction with hydrogen sulfide (H۲S), and the generation of polymeric deposits at elevated temperatures (۱۷۵–۳۵۰°C). This review highlights the need to optimize inhibitor formulations and process parameters to minimize deposit formation and enhance equipment service life. In fact the results show that although the large number of corrosion inhibitors developed and used in oil and gas processing, none fully protects against the formation of chemical deposits during the processing and transportation of oil and gas, especially at high temperatures. For instance, the most widely used amino-containing inhibitors, such as imidazolines and tertiary amines, maintain stability up to ۲۵۰°C, but decompose at higher temperatures, leading to deposit formation and so many other critical criterias which are highlighted in conclusion section.

کلیدواژه ها:

Corrosion inhibitors ، Thermal stability ، Hydrogen Sulfide ، nitrogen-containing compounds ، oil and gas refining