Calcite dissolution during hydrogen storage

[MMMM]

Hello
I intend to model calcite dissolution due to persence of hydrogen gas in the hydrogen storage process. when I use H2(g) to define the hydrogen gas, it reacts directly with all calcite rapidly and dissolves most of the mineral. but I now that H2(g) only reacts with calcite when dissolved in water.
Also, when  Hdg(g) is used to define gas, no reaction occurs.
How should I define a gas that reacts with minerals only a small part of what is dissolved in water?
I am grateful for your guidance.

Code: [Select]

[DATABASE C:\phreeqc\database\PHREEQC.dat
SOLUTION 1 Brine
end
GAS_PHASE 1
     -fixed_pressure
     -pressure 1
     -volume 2445
     -temperature 25
H2(g) 1
end
save solution 1
End
EQUILIBRIUM_PHASES 1
Calcite 0 10
end
REACTION_PRESSURE 1
0.1 400 in 11/code]

[dlparkhurst]

Search the forum for Hdg. There have been quite a few posts about hydrogen storage.

As you found out, if you use H2, then it will react with calcite immediately.

An alternative is to use Hdg and KINETICS. The -formula of kinetics would be -formula Hdg -1 H2 +1. The reaction would change unreactive Hdg to reactive H2. The problem will be to what extent and how fast the reaction occurs.

Because you probably do not know the rate or extent, you could also simply add H2 incrementally as a REACTION. This calculation would show the evolution of the solution if H2 does react to various extents.

[MMMM]

Thanks for your help