Cold Spray Coatings for Increased Corrosion Resistance in CO2-rich Environments

RIP2025-00049: Carbon capture and storage (CCS) networks are evolving to include complex composition carbon dioxide (CO2) streams from various anthropogenic sources. These emissions are often laden with flue gases and other impurities that can react with the dissolved water content in an otherwise benign CO2 stream to produce aggressive corrosive environments within CCS infrastucture. This becomes especially challenging on the storage end where complex compositions of dense phase CO2 meet and mix with brines and other fluids involved in the finishing process. To deal with the potential threat of accelerated corrosive attack in these environments, the EPA has issued recommendations to source higher chromium steels for storage wells. As higher resistance alloys are required, the infrastructure cost to sequester the CO2 increases and successively increases the economic burden of decarbonization writ large. One method to provide the necessary corrosion resistance without sourcing the entirety of the infrastructure from expensive corrosion resistant alloys is to apply only a thin film of the resistant alloy to a plain steel substrate via cold spray.

Cold spray application of thin boundary layers of resistant material on more cost effective substrate material presents a wide ranging opportunity to reduce cost of repair and deployment of new components in increasingly aggressive environments. The potential benefits range from enhanced corrosion resistance, to increased high temperature oxidation protection to wear protection in flowing conditions.

This work targets the use of cold sprayed CRAs (corrosion resistant alloys) onto mild steel substrates for improved resistance to CO2-rich environments to help meet the global demand for reducing the barriers to deployment of CCS solutions. Through iterative improvement in cold spray application technique and corresponding material resistance analysis in a dedicated CO2 corrosion testing facility, a robust matrix of material combinations and simulated environmental stresses is being investigated. The overall objective of this work was to provide a basis for leveraging the use of these relatively low cost cold spray coatings to improve the overall integrity of low alloy steel infrastructure against the aggressive conditions resulting from transport and storage of complex compositions of CO2.