(Project concluded in July 08, 2020)

The capture and storage of carbon dioxide (Carbon dioxide capture and storage-CCS) is a process consisting of separating CO2 from industrial sources and thermoelectric power generation and transporting to a storage location where it is isolated from the atmosphere.

Among the metallic materials, the use of high-strength low alloy (HSLA) steel for transporting supercritical CO2 (SCCO2) is the more economic option.

However these steels, when exposed to CO2 media with impurities such as H2O, H2S, NOx and SO2 may present a considerable increase in their corrosion rate. The corrosion of steels in systems containing CO2 has attracted considerable interest in the last decade, given its technological importance and also due to the environmental concerns associated with the greenhouse effect.

Polymer composite materials are also potentially technically and economically feasible for the manufacture of pipelines for the transport of supercritical CO2. From the point of view of design and manufacturing, these materials certainly meet the requirements for this application. However, their durability can be reduced by degradation caused by contaminants that may be present in the SCCO2 stream. For example, it is well documented that epoxy resins (widely used as a composite matrix polymer) is hygroscopic and that absorbed moisture can degrade the fiber / matrix interface over time.

In this project, the effect of impurities present in CO2 saturated aqueous phase will be investigated both related to corrosion of HSLA pipeline steels and on the degradation of composite materials with potential to be employed in SCCO2 transporting. A model will be developed to take into account the effect of liquid pressure on the corrosion/degradation phenomenom.

The last step of the project is also to investigate corrosion behavior of HSLA steel coated with composite material when exposed to the same conditions described above.