Acid Corrosion Inhibition With Secondary Acetylenic Alcohols

The mechanism of corrosion and the currently accepted theory of corrosion inhibition with respect to acetylenic alcohols is briefly considered. Several laboratory test methods for evaluating corrosion inhibitors are given. Factors affecting corrosion and corrosion control include type and concentration of corrosive medium, type of metal to be protected, temperature, amount of oxygen and impurities present, testing methods, and type and concentration of inhibitor. Secondary acetylenic alcohols (e.g., hexynol, and ethyl octynol) function as corrosion inhibitors specifically in aqueous mineral acids. Extensive laboratory data are presented on the prevention of metallic corrosion in aqueous mineral acids with secondary acetylenic alcohols. Such data point to industrial application in oil well acidizing (protection of API oil well tubing P-105 in 15 percent HCl at 250 F), acid cleaning (protection of aluminum and mild steel in 5 and 15 percent HCl at 104 and 150 F respectively) and acid pickling (protection of mild steel in 15 percent HCl at 150 F and 15 percent H2SO4 at 187 F). Studies also indicate that hexynol may be used as a component in an inhibitor mixture to prevent corrosion of mild steel by concentrated grades of H3PO4 5.8.2, 4.3.2