Environmental phosphate coating for corrosion prevention in CO2 pipelines

The pipelines transporting carbon dioxide (CO2) rich fluids in the CO2 capture and storage (CCS) process require an appropriate internal corrosion protection in cases where the stream is acidic due to the formation of carbonic acid. In this study, vanadate-based MnMgZn phosphate coating is proposed as effective coating to reduce the corrosion in pipelines. The vanadate in the phosphate bath refines the microstructure of the phosphate coating and alters the corrosion behavior significantly. Electrochemical impedance spectroscopy (EIS) and polarization measurements were performed to investigate the corrosion behavior of phosphate coatings in diluted sulfuric acid at different pH.

► The transporting CO2 rich fluids require economical coatings for CO2 pipelines.
► MnMgZn phosphate is green coating for CO2 pipelines.
► Vanadate enhances the corrosion resistance by refining the phosphate microstructure.