Carbon dioxide capture, transportation, and geological storage — Cross Cutting Issues — CO2 stream composition

The primary aim of this document is to describe the main compositional characteristics of the CO2 stream downstream of the capture unit, taking into account common purification options. Accordingly, this document will characterize the different types of impurities and present examples of concentrations determined in recent capture pilot projects as well as through literature review. It identifies ranges of concentrations, giving priority to in situ measurements when available.

The second aim of this document is to identify potential impacts of impurities on all components of the CCS chain, from surface installations (including transport) to the storage complex. For example, impurities can have a significant effect on the phase behaviour of CO2 streams in relation to their concentration. Chemical effects also include the corrosion of metals. The composition of the CO2 stream can also influence the injectivity and the storage capacity, due to physical effects (such as density or viscosity changes) and geochemical reactions in the reservoir. In case of a leakage, toxic and ecotoxic effects of impurities contained in the leaking CO2 stream could also impact the environment surrounding