water dissolve in CO2 gas

[Yongqiang]

Hi Everyone,

I am not sure if water can dissolve CO2 in a gas status. It means the water is vaporized in the CO2 gas. Can phreeqc do this work?

Cheers,
Yongqiang

[dlparkhurst]

PHREEQC allows gas-water reactions. Often, you only need EQUILIBRIUM_PHASES to specify fixed partial pressures of gases, for example to maintain partial pressure of CO2(g) at atmospheric level of 10^-3.4.

The other option is to use GAS_PHASE. Either fixed pressure--a gas bubble where the volume expands and contracts and may dissolve completely, or a fixed volume gas that always has the same volume and always exists, but the pressure varies. The following represents 1 L of sodium bicarbonate solution brought in contact with a gas head space of 1 liter.

Code: [Select]

SOLUTION 1
pH 7 charge
Na   1
C(4) 1
END
USE solution 1
GAS_PHASE
-fixed_volume
-volume 1
CO2(g) 0
H2O(g) 0
END


[Yongqiang]

Hi David,

When the equilibrium is reached, what is the status of each phase? Are they all in liquid or in gas?

Regards,
Yongqiang

[dlparkhurst]

Run it and look at the output file. Then ask your question.