wall.gms : Chemical Equilibrium Problem

Description

A Sample Nonlinear system to solve Chemical Equilibrium models.

Reference

  • Wall, T W, Greening, D, and Woolsey, R E D, Solving Complex Chemical Equilibria Using a Geometric-Programming Based Technique. Operations Research 34, 3 (1987), 345-355.

Small Model of Type : NLP


Category : GAMS Model library


Main file : wall.gms

$Title Chemical Equilibrium Problem (WALL,SEQ=76)

$Ontext

   A Sample Nonlinear system to solve Chemical Equilibrium models.


Wall, T W, Greening, D, and Woolsey, R E D, Solving Complex Chemical
Equilibria Using a Geometric-Programming Based Technique. OR 34, 3 (1987).

$Offtext

Variables ba, so4, baoh, oh, hso4, h ;

Equations r1, r2, r3, r4, b1, b2 ;

* scaling in powers of 10: ba -5, so4 -5, baoh -12, oh -7, hso4 -10, h -7

r1..  ba * so4 =e= 1 ;
r2..  baoh / ba / oh =e= 4.8 ;
r3..  hso4 / so4 / h =e= .98 ;
r4..  h * oh =e= 1 ;
b1..  ba + 1e-7*baoh =e= so4 + 1e-5*hso4 ;
b2..  2 * ba + 1e-7*baoh + 1e-2*h =e= 2 * so4 + 1e-5*hso4 + 1e-2*oh ;

Model wall / all / ;
ba.l=1; so4.l=1; baoh.l=1; oh.l=1; hso4.l=1; h.l=1;
Solve wall using nlp minimizing ba;