Investigation of efficient corrosion inhibitor during acid cleaning of reverse osmosis (RO) desalination plant. (November 2022) - Wang, Dan-Yang
Abstract: Reverse osmosis (RO) technology plays a vital role in seawater desalination production, while salt scaling phenomenon is an inevitable problem during operation. Accordingly, glucuronide-substituted catechin (CG) was synthesized and developed here as an eco-friendly inhibitor for the first time, whose corrosion inhibition performances for desalination equipment alloys (i.e., carbon steel, brass, Ni-resist, and 316 L stainless steel) in 2% HCl solution were evaluated by experiments and theoretical calculations. At a concentration of 200 mg/L, CG achieved 97.81% corrosion inhibition for carbon steel, 85.91% for Ni-resist, 92.11% for brass, and 77.95% for 316 L stainless steel in weight loss experiments. The 90-hours static stability test was carried out by weight loss method, and the inhibition performance of CG was compared with that of a commercial corrosion inhibitor used in seawater desalination plant. The structural of the protective film on the metal surface was analyzed by EDX and XPS. Quantum chemical calculations based on density functional theory (DFT) and MD simulations were performed to optimize the CG molecular structure and investigate the inhibitive properties on the theoretical level, which agree well with the experimental results. Graphical Abstract: ga1 Highlights: A catechin-glucuronide (CG) hybrid was developed as a green corrosion inhibitor. CG is effective inhibitor for ferrous-based alloys under typical acid cleaning conditions of RO desalination plant. The formation of CG film on alloys surface was confirmed by SEM, EDX and XPS. CG exhibits mixed type behavior toward the inhibition of ferrous-based alloys.