The sequestration of CO2 is an important technology to be promptly developed if fossil fuels are
continued to be used and CO2 emission to the atmosphere is to be reduced. Low alloy carbon steel
pipelines are being considered to transport the supercritical CO2 from power plants to underground
sequestration sites. However, the CO2 stream will not be pure and dry, but will contain a number of
corrosive contaminants. We have developed an experimental system that allows the use of a number of
in-situ electrochemical techniques, such as electrochemical impedance spectroscopy, linear sweep
voltammetry, and cyclic voltammetry, at elevated temperature and pressure. These methods are used
to measure the parameters of the real time corrosion process without removing the sample from the
system. This paper describes the design of the apparatus and presents the results of our first
measurements of corrosion of carbon steel in supercritical CO2 doped with H2O at 50 ºC and 15 MPa.
The first conductivity measurements in the dry and water-saturated supercritical CO2 fluid are also
presented in this paper.
Key words: CO2 sequestration, corrosion of carbon steel, supercritical CO2 fluids, electrochemical
techniques