Hybrid model development emulating linear polarization resistance method towards optimizing dosages of corrosion inhibitors

Abstract

A hybrid model was developed using data obtained from a full-scale cooling water cycle of a chemical plant to capture complex interactions between water qualities and added chemicals, so that the model can be used to study corrosion of metals in complex water matrices. The model is based on an adaptation of the Butler-Volmer equation. It relies on easily measurable water qualities, chemical dosages and linear polarization resistance measurements. The current study demonstrates the model's applicability in the simultaneous optimization of dosages of multiple corrosion inhibitor in real-time. Models developed for dosage optimization in the literature rely on corrosion inhibition efficiencies in simple water matrices determined using electrochemical impedance spectroscopy and potentiodynamic polarization, which cannot be comprehensively applied to complex water matrices containing multiple inhibitors. The current study enables using regular LPR measurements of a cooling water cycle to predict the corrosion rate, potentially optimize dosages of multiple corrosion inhibitors and analyze corrosion mechanisms.