[butler volmer kinetics?]

I am trying to model a polarization scan of Mg++ solution (attached). When talking with an electrochemists they were a bit confused to the the electrochemical kinetics used in GWB, is it bulter volmer? Also how is GWB linking electrochemical potential to mols of electrons when sliding the Eh.

initial configuration-2.rea

[Numerical Export in P2plot]

Hi,

I am looking at altering logK values and how those changes fit experimental data. I would like to quantitatively assess the goodness of fit of the simulated phase diagram with the experimental data points. Is there a way to obtain the numerical/tabulated values from P2plot directly?

Thank you,

Andrew

[Pourbaix diagram using Phase2]

Hi,

I have the same issue as Frank as seen above. I am try to model the Al-Na-Cl-H2O-CO2 system and look at the Pourbaix diagram over the entire eH pH range as mentioned above. I am able to do the calculation from pH = 0 to pH =9, and from Eh = -0.55 to Eh = 0.75, but anything outside of the range crashes and the program must be restarted.

Also as Frank mentioned if I use Act2 to try to replicate the Phase2 calculation, the results are not entirely consistent.

What are some tricks or ways to run the Phase2 at a full Eh/pH range?

 

Thanks,
Andrew

 

Eh pH diagram.ph2

[Reference State of Solid Al]

To update a database to including additional aluminum phases, would I add the reference state of solid aluminum, reaction written in terms of Al+++, as a mineral species, as a redox couple, or both?

From data0 file:

Aluminum                Al
     sp.type =  solid   refstate
     [ ]
     V0PrTr  =      9.999 cm^3/mol [source: 79rob/hem]
****
     1 element(s):
      1.0000 Al
****
     5 species in reaction:
    -1.0000  Aluminum                    -3.0000  H+
    -0.7500  O2(g)                        1.0000  Al+++
     1.5000  H2O
*
**** logK grid [0-25-60-100C @1bar; 150-200-250-300C @Psat-H2O]:
       162.4309  147.0709  129.3964  113.2275
       500.0000  500.0000  500.0000  500.0000