A self-healing composite coating for CCUS: Synergistic anticorrosion and durability in harsh environments

Carbon Capture, Utilization and Storage (CCUS) technology emerges as a promising solution amid global efforts to mitigate emissions and enhance energy efficiency. However, within the CCUS framework, metal transport pipelines encounter significant corrosion challenges, particularly in high-pressure CO₂ corrosion environments. Here, a novel composite filler was prepared by modifying α-ZrP nanosheets with tannic acid (TA) and octadecylamine (ODA), and then introduced into epoxy resin (EP) to obtain the self-healing multifunctional anti-corrosive coating named ZPO/EP. Compared to pure EP, it reduces CO₂ and water vapor permeability by 69.77 % and 65.16 %, respectively, and the cohesion between the resin and filler has been significantly improved, resulting in a reduction of coating defects and enhancement in the adhesion between the coating and the metal substrate. Most importantly, the coating exhibits excellent long-term anti-corrosion performance under simulated CCUS conditions. After being exposed to these conditions for 30 days, its impedance value reaches 7.25×10¹⁰ Ω·cm² at 0.01 HZ_. Meanwhile, the polyphenol groups of the ZPO filler can chelate with Fe²⁺, endowing the coating with self-healing properties. This study offers an effective solution for corrosion protection of equipment in CCUS systems, which is crucial for promoting the large-scale application and sustainable development of CCUS technology.