Open AccessThree‐phase equilibrium and partitioning calculations for CO 2 sequestration in saline aquifers
Author(s) -
Fuller R. C.,
Prevost J. H.,
Piri M.
Publication year - 2006
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2005jb003618
Subject(s) - flash evaporation , brine , thermodynamics , solubility , aquifer , salinity , phase equilibrium , bubble point , dew point , environmental science , bubble , materials science , chemistry , phase (matter) , mechanics , geology , groundwater , physics , geotechnical engineering , oceanography , organic chemistry
We show how the use of appropriate variables results in a flash calculation that uses only equilibrium constraints; it is thus not necessary to solve the mass balance equations self‐consistently with the equilibrium equations. We use this implicit material balance in flash calculation. We show its advantages over the current approach that uses an explicit material balance. For the flash calculation for CO 2 storage in brine aquifers, use of appropriate variables also allows us to find the dew, bubble, and precipitation points where the liquid, vapor, and solid salt phases, respectively, emerge. Our calculation includes the water content of the vapor phase, which arises from evaporation of the brine. Evaporation leads to increased brine salinity, which results in a large reduction in CO 2 solubility in the salting‐out effect, and eventually in precipitation of solid salt and ultimately the disappearance of the liquid phase. The flash calculation also relies on our derivation of fugacities for H 2 O and CO 2 in both the brine and the vapor phase.