Water Content of CO2 in Equilibrium With Liquid Water and/or Hydrates

Abstract

Summary Experimentally measured water content in CO2-rich fluid in the gaseous or liquid state in equilibrium with liquid water or hydrate is presented for pressures ranging from 100 to 2,000 psia [0.69 to 13.79 MPa] and temperatures from −19 to 77°F [−28.33 to 25.0°C]. The water content of the CO2-rich phase along the three-phase equilibria, i.e., liquid water/liquid CO2/gas to the three-phase critical endpoint, is also reported. The experimental results from this study on the water content in the CO2-rich phases have been combined with earlier research results of the CO2/water binary system in the hydrate-free region from 77 to 200°F [25.0 to 93.33°C] and pressures to 3,000 psia [20.69 MPa] to produce a comprehensive plot. The high degree of complexity in the phase behavior of a CO2/water binary system, which exhibits several pairs of equilibrium phases for the conditions, is shown. To make the data more intelligible than they are in their raw form, the data are presented in terms of the pressure enhancement of the water content along isotherms. Finally, the activity coefficients of water in the CO2-rich phases are summarized.