Gastherm Update for Gasworks and Solvgas
As of 2022 there is renewed interest in programs Gasworks and
Solvgas, using Gastherm.dat as their thermodynamic data source. A
significant issue is the absence of most digital records of the
enthalpy, entropy, and heat capacity data that were used to compute
the log K's for the gases. If logK's within Gastherm are to be
modified (i.e. addition to or improvement upon) then records of
enthalpy, entropy, and heat capacity are essential for each gas,
mineral/solid, and liquid. Herein we document the construction of a
new Gastherm database, and the data used for it. While the sources
of data are well documented, all of it must be recompiled from
scratch.
The 1990 version —
- Gastherm 1990 with some minor
modifications. Add a text delimiter between derived gases and
solids, and remove blank lines where in the past they were
required for 16-bit operating systems wherever the preceding
line exceeded 72 characters. A name change for one item only
Al2O3 glass, from "Al2O3(g)" to "Al2O3-gl". Some revision of the
text header. Gasworks and Solvgas modified to accommodate these
changes. These will be the only changes to the programs until
after completion of the Gastherm update, in a perfect world
[May-2022].
- Demo files for Gasworks and Solvgas
A summary of the procedure to update
Gastherm —
- Find in the references the enthalpy, entropy, and heat
capacity for each gas, or each mineral/solid or liquid, and add
those to the Supcrt database.
- Use these programs-
- SupcrtRxnGT
- creates Supcrt reaction files. Uses input files Gastherm.dat
and one of two (incrementally updated) name index tables,
to [Nov-2022].
- Supcrt96
- computes logK's. Uses input files from SupcrtRxnGT,
above [1996].
- Gastab
- generates Gastherm-formatted records from Supcrt96
logK output. Uses input files Gastherm.dat, one of the the
name index tables, and Supcrt96 output [Feb-2023].
- RegressGT
- generates the last line of each Gastherm record, regression
coefficients for interpolating logK's at intermediate
temperatures using the equation logK(T,°K) = a + b T-1
+ c T + d T-2 + e log(T) [Mar-2023].
- Insert the new data into Gastherm
More info —
- SupcrtRxnGT
— Reads a previous version of Gastherm, name index tables to
reconcile names between Gastherm and the Supcrt database, and
writes a reaction file for Supcrt. Largely complete [Nov-2022].
- Input files:
Gastherm.dat
GTgases.tbl, index table of derived gas names, 5
items
GTsolids.tbl, index table of mineral, solid, and
liquid names, 4 items
- Output files:
GTgases.rxn, Supcrt reaction file for gases, or
in a separate run:
GTsolids.rxn, Supcrt reaction file for solids and
liquids
MissingItems.dat, items that are missing from the
index tables
- Accessory name index files. Species will be copied from
"all" to "current" as they are added to the Supcrt database:
GTgases.all.tbl, 585 items
GTgases.current.tbl, 5 items
GTsolids.all.tbl, 399 items
GTsolids.current.tbl, 4 items
- Supcrt96
— Identical to a copy elsewhere on this site, but with data
limited to those more relevant to the task at hand.
- Input files:
dpronshp.dat, thermodynamic data
GT.con, temperature and pressure array
GT*.rxn, reaction file
- Output file:
Name = *dealer'schoice*.*
- Gastab
— Reads Supcrt96 output, the previous version of Gastherm used
to generate the the Supcrt reaction file, and the aforementioned
name index tables, and writes records properly formatted for
Gastherm, but without regression coefficients.
- Input files:
Gastherm, the same version used to generate the
Supcrt96 reaction file
One of the two name index tables, the same as
for SupcrtRxnGT
Supcrt96 logK output (name = *dealer'schoice*.*
from above)
- Output file:
Name = *adifferentchoice*.* (different from
the input file name.)
- RegressGT
— Reads logK's in Gastab output containing the almost finished
Gastherm records, computes the regression coefficients, and
inserts those into the fourth and last line of each record, in a
copy of the input file.
- Input file: RegrunGT.dat. The first line should show an
integer count of the records that follow.
- Output files: RegoutGT, RegpltGT.dat