Internal corrosion of CO2 pipelines for carbon capture and storage

Abstract

Capturing and storage of anthropogenic CO2 requires the transport of CO2 with varying combinations of impurities depending on the capture technology and source. Traditional gas pipelines are not designed for the transport of such relatively low purity CO2, in fact, initial research indicates that a low-purity CO2 environment poses a significant durability risk to conventional (gas) pipelines. In a supercritical CO2 stream, the presence of water will lead to acidic conditions via the formation of carbonic acid. In this work a round robin of experiments has been conducted in aqueous solutions where CO2 has been added to water to form carbonic acid in-situ, along with testing in sulfuric acid that was found to simulate the impact of carbonic acid upon steel. The role of Cl-, NO3- and SO42- impurities was also investigated. We see that there is merit in such high throughput tests to form an initial understanding which can be subsequently benchmarked by supercritical CO2 tests.