State of the aqueous phase in liquid and supercritical CO2 as relevant to CCS pipelines

► The flow in CO2 and H2O mixture will be stratified wavy flow. ► HCl, HNO3 and SO3 will have a dramatically effect on the pH of the aqueous phase. ► An aqueous phase in a CO2 stream from a clean source will have a pH from 1.5 to 3.2. ► An aqueous phase in CO2 stream from a polluted source will have a pH from −1.5 to 1.5.