PhreeqcUsers Discussion Forum

Conceptual Models => Database selection and modification => Topic started by: DBM_Leeds on 22/04/15 14:16

Title: Best database for simulations at 60 - 120 degrees?
Post by: DBM_Leeds on 22/04/15 14:16

Hi all

I want to run some very simple & quick simulations of waters from a geothermal power plant (60 - 120 degree C) in Iceland. I have the analyses of the fluid and want to know the following:
- SI of minerals (especially SiO2 amorphous)
- pH in-situ (as compared to the one measured at 20 degrees in the lab)

My question now is: which database is best to use? In the following reference the authors have used the wateq4 database.

Tobler, Dominique J., Andri Stefansson, and Liane G. Benning. "In‐situ grown silica sinters in Icelandic geothermal areas." Geobiology 6.5 (2008): 481-502.

Is that a good idea or is there a better option?

Thanks for your help!
Daniela

Title: Re: Best database for simulations at 60 - 120 degrees?
Post by: dlparkhurst on 02/05/15 23:59

Tony Appelo has been working on temperature dependence in phreeqc.dat and pitzer.dat. I would start with those, or llnl.dat.

Title: Re: Best database for simulations at 60 - 120 degrees?
Post by: DBM_Leeds on 08/05/15 10:52

Thank you very much for this information!

Title: Re: Best database for simulations at 60 - 120 degrees?
Post by: Steve on 19/05/15 02:32

The French Geological Survey (BRGM) public database THERMODDEM which is now at the December 2014 release is excellent for the 60 - 120 C temperature region.
http://thermoddem.brgm.fr/

Also this paper has useful thermo data for geothermal (and hydromet) systems:
Arodottir et al. (2012) Development and evaluation of a thermodynamic dataset for phases of interest in CO2 mineral sequestration in basaltic rocks. Chemical Geology 304-305, pp26 - 38