|
GEMINI : Gibbs Energy MINImizer |
GEMINI softwares are thermochemical equilibria
calculation codes specially developed to take into account :
- an ideal gaseous phase
- condensed compounds
- solutions.
The method used is a minimization
of the total Gibbs energy of the system under either constant pressure or
volume conditions. The minimization method is based on a general
optimization technique which has been applied to the chemical equilibrium
problems.
The minimum of the Gibbs energy is found subject to :
·
the mass balance
conditions
·
the non-negative
condition (the mole values cannot be negative).
·
The initial
composition
·
The chosen process
(isotherm, adiabatic, constant volume or pressure).
The calculation outputs supply all the basic informations concerning a
calculated equilibrium state :
- names, composition and fraction of the different
phases
- component activities
- partial pressure of gaseous species
Automatic iteration
capabilities are offered, either in temperature or composition.
The datafiles can be
directly created with the software COACH, or the user can create his own
ones with a text editor.
GEMINI 1
This code is used if condensed
species have fixed activities.
To see a numerical result,
click here.
This software, really easy
to use, will be extremely useful for all those working in chemical
engineering : chemists, material scientists, ceramics, involved in the
treatment of thermochemical equilibria.
Demo version for Windows : please contact us
GEMINI 2
The thermodynamic modeling
of substances and solutions is programmed in the code. Substances are described
by using a general formula of the Gibbs Energy as a function of temperature
with several ranges.
The generalized multisublattice model, including the substitution model and the
non ideal associate model, is used to describe Gibbs Energy of solutions.
GEMINI2 allows the user to solve very complex
multicomponent multiphase equilibria problems (equilibrium composition,
constituents properties, phase diagrams).
The software allows the user to tabulate, numerically or graphically,
thermodynamic functions of substances and solutions.
To see a numerical complex
calcul, click here.
Demo version for Windows : 
Webmaster(thermodata@grenet.fr)
updating : 01/02/04