Sixeq2a

Name: Sixeq2a - Steady state solution for reaction rate equations - 1st parameter set
Source: Shacham, M., pp. 891-923 in A. W. Westerberg and H. H. Chien (Eds),
  Proc. of FOCAPD 2, CACHE Publications, Ann Arbor, Michigan, 1984.
Reference/s Bullard, L. G. and Biegler, L. T., Computers Chem. Engng. 15(4), 239 (1991).
       
Model: 6 implicit equations, indep. variables x1 to x6
  Average difficulty level
  Constraints: xi are nonnegative for I=1,2,…6
  Discontinuities: none
  Initial estimates: 1. (0.99, 0.05, 0.05, 0.99, 0.05, 0); 2.(0.05, 0.99, 0.05, 0.05, 0.99, 0);
       
Solved by Shacham, M., POLYMATH 5.1, build 19, April 9, 2001
       
Model Eqs. Steady state solution for reaction rate equations - 1st parameter set |POLVER05_1

EXCEL FILE 

f(x1) = 1-x1-k1*x1*x6+kr1*x4 #

TEXT FILE 

f(x2) = 1-x2-k2*x2*x6+kr2*x5 #

POLYMATH FILE 

f(x3) = -x3+2*k3*x4*x5 #
  f(x4) = k1*x1*x6-kr1*x4-k3*x4*x5 #
  f(x5) = 1.5*(k2*x2*x6-kr2*x5)-k3*x4*x5 #
  f(x6) = 1-x4-x5-x6 #
  k1 = 31.24 #
  k2 = 2.062 #
  kr1 = 0.272 #
  kr2 = 0.02 #
  k3 = 303.03 #
  x1(0)=.99
  x2(0)=.05
  x3(0)=.05
  x4(0)=.99
  x5(0)=.05
  x6(0)=0
       
Variable/function values Variable Value f(x)
  x1 0.99 0.279
  x2 0.05 0.951
  x3 0.05 29.950
  x4 0.99 -15.269
  x5 0.05 -15.001
  x6 0 -0.04
  k1 31.24  
  k2 2.062  
  kr1 0.272  
  kr2 0.02  
  k3 303.03  
       
Solution Variable Value f(x)
  x1 0.9700739407529 0
  x2 0.9800492938353 -3.686E-17
  x3 0.0598521184942 -1.388E-17
  x4 0.9900268865935 0
  x5 0.0000997509107 0
  x6 0.0098733624958 4.337E-17
       
Infeasible solution Variable Value f(x)
  x1 1.0332985964390 3.88E-17
  x2 1.0221990642970 6.94E-17
  x3 -0.0665971928906 -8.83E-13
  x4 -0.0001097977609 4.45E-13
  x5 1.0011422708840 4.42E-13
  x6 -0.0010324725201 -3.9262E-13
       
Additional information Most algorithms converge to the infeasible solution from
  the second initial estimate