CO2 Solubility [CO2 Sequestration]

1. In the context of CO2 sequestration applications requiring reliable thermodynamic models, with SRK & PR (EoS) being inexact with reference to their density prediction (in estimating liquid and super-critical phase densities), can we still go ahead with PR’s 2-parameter EoS towards estimating liquid density (‘only’ @ their saturation levels) in CO2 sequestration applications?

Can these EoS successfully reproduce VLE around critical point for a CO2-brine system?

OR

Should we apply the (temperature-independent) Volume Translation parameter (which can probably be computed from Rackett equation in the absence of experimental data)?

Linear mixing rule would remain to be valid in a CO2-brine system?

2. With a fixed critical compressibility factor, do we still require the calculation of liquid density using SRK or PR @ critical point in CO2 sequestration applications?

OR

With coupled advantages of activity coefficient models & EoSs, should we prefer 3-parameters cubic EoS towards considering dynamic critical compressibility factor towards estimating saturated liquid and critical densities?

3. Whether the 3-parameter cubic EoS with Wong-Sandler mixing rules would remain to be more appropriate in CO2 Sequestration applications?

4. If the activity of CO2 gets influenced differently by different ions, then, whether, CO2 sequestration application require solubility of CO2 in the presence of multivalent ions as against the conventional application of solubility of CO2 in single-ion systems?

Can we treat the presence of various multivalent ions as a single ion using Sinclair multipliers in reactive reservoir rocks?

Suresh Kumar Govindarajan

08-Dec-2024