Threeq7

Name: Threeq7 - Steady state operation of an adiabatic CSTR
Source: Seadet, J. D. et al., Computers chem. Engng.,14 71(1990).
Reference/s Gupta, Y.P. (1995). Ind. Eng. Chem. Res. 34, 536-544
       
Model: 3 implicit equations, indep. variables CA, CB and T
  Lower difficulty level
  Constraints: 0<=CA<=1, 0<=CB<=1, 0<=CC<=1, T>0
  Discontinuities: Undefined for T=0 and when 1+KA*CB=0
  Initial estimates: 1.T=300, CA=3, CB=0; 2. T=350, CA=3, CB=0;
  3.T=400, CA=3, CB=0; 4.T=600, CA=3, CB=0;
  5. T=700, CA=3, CB=0;
       
Solved by Shacham, M., POLYMATH 5.1, build 19, April 5, 2001
       
Model Eqs. Steady state operation of an adiabatic CSTR |POLVER05_3

EXCEL FILE 

f(CA) = CA0-CA-theta*k1*CA/(1+KA*CB) #

TEXT FILE 

f(CB) = CB-CB0-(theta*k1*CA/(1+KA*CB)-theta*k2*CB+theta*k2p*CC) #

POLYMATH FILE 

f(T) = 85*(T-T0)+0.02*(T^2-T0^2)-((16000+3*T-0.002*T^2)*((CA0-CA)/CA0)

+(30000+4*T-0.003*T^2)*CC/CA0) #

  CC = (CC0+theta*k2*CB)/(1+theta*k2p) #
  k1 = 4e6*exp(-60000/(8.314*T)) #
  KA = 17*exp(-7000/(8.314*T)) #
  k2 = 3e4*exp(-80000/(8.314*T)) #
  k2p = 3e4*exp(-90000/(8.314*T)) #
  T0 = 298 #
  CA0 = 3 #
  CB0 = 0 #
  CC0 = 0 #
  theta = 300 #
  CA(0)=3
  CB(0)=0
  T(0)=300
       
Variable/function values Variable Value f(x)
  CA 3 -1.2853E-01
  CB 0 -1.2853E-01
  T 300 1.9392E+02
  CC 0.00  
  theta 300  
  k1 1.428E-04  
  KA 1.027E+00  
  k2 3.527E-10  
  k2p 6.400E-12  
  T0 2.980E+02  
  CA0 3.00  
  CB0 0.00  
  CC0 0.00  
       
Solution 1 Variable Value f(x)
  CA 2.7873203092940 -3.0531E-16
  CB 0.2126796260201 -3.0531E-16
  T 310.212556340 -2.2737E-13
  CC 6.4686127E-08  
  k1 3.152768321E-04  
  KA 1.1264778653520  
  k2 1.013827367E-09  
  k2p 2.099275102E-11  
       
Solution 2 Variable Value f(x)
  CA 2.3804209271400 9.9920E-16
  CB 0.6195774301750 1.1102E-15
  T 333.492475848 -9.0949E-13
  CC 1.6426848E-06  
  k1 1.599455327E-03  
  KA 1.3614614093880  
  k2 8.837662641E-09  
  k2p 2.398774591E-10  
       
Solution 3 Variable Value f(x)
  CA 0.1263969394304 8.8818E-16
  CB 2.8499084983470 1.3323E-15
  T 462.569151959 -3.6380E-12
  CC 2.369456222E-02  
  k1 6.705676413E-01  
  KA 2.7539764669600  
  k2 2.773094840E-05  
  k2p 2.059184000E-06  
       
Solution 4 Variable Value f(x)
  CA 3.801064064E-03 -8.8818E-16
  CB 1.7136336431310 2.4425E-15
  T 594.027432439 -3.6380E-11
  CC 1.2825652928060  
  k1 2.117809213E+01  
  KA 4.1199826416980  
  k2 2.768367299E-03  
  k2p 3.654782339E-04  
       
Solution 5 Variable Value f(x)
  CA 3.797570282E-04 5.3291E-15
  CB 0.6888918938783 2.6645E-15
  T 691.624151130 2.9104E-11
  CC 2.3107283490930  
  k1 1.176034598E+02  
  KA 5.0321966065050  
  k2 2.722292150E-02  
  k2p 4.782570881E-03