Water content in pure CO₂ and CO₂-rich mixtures using the DSH analytical technique

The accurate determination of water content in equilibrium with hydrates helps to prevent operational problems related to flow assurance, and it is essential for the emerging Carbon Capture and Storage (CCS) processes for decarbonization. However, the experimental challenges associated with these measurements cause a scarcity of data. The development of the Differential Scanning Hygrometer (DSH) method has increased the number of water content reports for CO₂-rich systems in equilibrium with hydrates. It monitors not absolute values but fluctuations in the water content due to the formation of ice or dew inside a temperature-controlled tube. Here, we provide experimental and modeling investigation for water content on pure CO₂ and two CO₂-rich mixtures (CO₂+CH₄ and CO₂+CH₄+N₂) in equilibrium with hydrates: the sCPA and the SRK+EMS equations of state were used to model the obtained experimental data, both using the van der Waals-Platteeuw (vdW-P) model for the hydrate phase.