The inhibition of steel corrosion in hydrochloric acid with 3-phenyl-2-propyn-1-ol

Abstract

3-Phenyl-2-propyn-1-ol (PPO) effectively mitigates the corrosion of API J55 oilfield tubing in HCl solutions over a wide range of conditions. Product analyses reveal that PPO can undergo hydration on the steel surface or, more slowly, in solution to form β-hydroxypropiophenone (HPP). If adsorbed on the steel, HPP rapidly dehydrates to yield phenyl vinyl ketone (PVK). The latter can oligomerize to form poly(phenyl vinyl ketone). Corrosion kinetics measurements indicate that PPO, HPP (both in protonated form) or PVK can all function as primary inhibitors. The oligomer film serves as a secondary barrier which can bring about an additional reduction of the corrosion rate. Under most conditions, the film quickly reaches a near-constant thickness in accord with the fall-off in corrosion rate.