14eq1

Name: 14eq1 - Three stage, two component distillation column
Source: Cutlip, M. B. and Shacham, M, Problem Solving in Chemical
  Engineering with Numerical Methods (2nd Ed.), Prentice Hall Inc.,
Reference/s      
Model: 14 implicit equations, indep. variables x11, x12, x13, x21, x22, x23, t1, t2, t3, tf, t0, V1, V2 and V3
  Average difficulty level
  Constraints: All the variables (except the temperatures: ti ) are nonnegative
  Discontinuities: Undefined for some negative temperature (ti) values
  Initial estimates: 1.(0.5, 0.4, 0.3, 0.3, 0.4, 0.5, 145, 190, 210, 200, 200, 1, 1, 1) ;
  2. (0.1, 0.1, 0.1,0.1, 0.1, 0.1,100, 100, 100, 100, 100, 5, 5, 5)
       
       
Solved by Shacham, M., POLYMATH 5.1, build 19, April 18, 2001
       
Model Eqs. Three stage, two component distillation column |POLVER05_1

EXCEL FILE  

f(x11)=-((V1-L0)*k11+L1)*x11+V2*k12*x12 #

TEXT FILE 

f(x12)=L1*x11-(V2*k12+L2)*x12+V3*k13*x13+z1*F #

POLYMATH FILE 

f(x13)=L2*x12-(V3*k13+B)*x13 #
  f(x21)=-((V1-L0)*k21+L1)*x21+V2*k22*x22 #
  f(x22)=L1*x21-(V2*k22+L2)*x22+V3*k23*x23+z2*F #
  f(x23)=L2*x22-(V3*k23+B)*x23 #
  f(t1) = k11*x11+k21*x21-1 #
  f(t2) = k12*x12+k22*x22-1 #
  f(t3) = k13*x13+k23*x23-1 #
  f(tf) = k1f*z1+k2f*z2-1 #
  f(t0) = k10*k11*x11+k20*k21*x21-1 #
  f(V1) = -V1*hv1+V2*hv2-L1*hl1+L0*h0 #
  f(V2) = -V2*hv2+V3*hv3+hf+L1*hl1-L2*hl2 #
  f(V3) = -V3*hv3+Q+L2*hl2-L3*hl3 #
  L0=V1-D #
  L1=V2-D #
  L2=V3+F-D #
  L3=B #
  hl1 = t1*(29.6+0.04*t1)*x11+t1*(38.5+0.025*t1)*x21 #
  hv1=(8003+t1*(43.8-0.04*t1))*k11*x11+(12004+t1*(31.7+0.007*t1))*k21*x21 #
  hl2=t2*(29.6+0.04*t2)*x12+t2*(38.5+0.025*t2)*x22 #
  hv2=(8003+t2*(43.8-0.04*t2))*k12*x12+(12004+t2*(31.7+0.007*t2))*k22*x22 #
  hl3=t3*(29.6+0.04*t3)*x13+t3*(38.5+0.025*t3)*x23 #
  hv3=(8003+t3*(43.8-0.04*t3))*k13*x13+(12004+t3*(31.7+0.007*t3))*k23*x23 #
  hf = tf*(29.6+0.04*tf)*z1+tf*(38.5+0.025*tf)*z2 #
  h0 = t0*(29.6+0.04*t0)*k10*k11*x11+t0*(38.5+0.025*t0)*k20*k21*x21 #
  k11=10^(6.80776-935.77/((t1-32)*5/9+238.789))/P #
  k12 = 10^(6.80776-935.77/((t2-32)*5/9+238.789))/P #
  k13=10^(6.80776-935.77/((t3-32)*5/9+238.789))/P #
  k21 = 10^(6.85296-1064.84/((t1-32)*5/9+232.012))/P #
  k22=10^(6.85296-1064.84/((t2-32)*5/9+232.012))/P #
  k23=10^(6.85296-1064.84/((t3-32)*5/9+232.012))/P #
  k1f = 10^(6.80776-935.77/((tf-32)*5/9+238.789))/P #
  k2f = 10^(6.85296-1064.84/((tf-32)*5/9+232.012))/P #
  k10 = 10^(6.80776-935.77/((t0-32)*5/9+238.789))/P #
  k20 = 10^(6.85296-1064.84/((tf-32)*5/9+232.012))/P #
  F=1 #
  z1 = 0.40 #
  z2 = 1-z1 #
  B=0.75 #
  D=0.25 #
  P=760*120/14.7 #
  Q = 10000 #
  y11 = k11*x11 #
  y12 = k12*x12 #
  rec = y11*D/(z1*F) #
  x11(0)=0.5
  x12(0)=0.4
  x13(0)=0.3
  x21(0)=0.3
  x22(0)=0.4
  x23(0)=0.5
  t1(0)=145
  t2(0)=190
  t3(0)=210
  tf(0)=200
  t0(0)=200
  V1(0)=1
  V2(0)=1
  V3(0)=1
       
Variable/function values Variable Value f(x)
  x11 0.5 0.087
  x12 0.4 0.037
  x13 0.3 -0.051
  x21 0.3 -0.031
  x22 0.4 0.258
  x23 0.5 -0.023
  t1 145 -0.507
  t2 190 -0.220
  t3 210 -0.126
  tf 200 -0.002
  t0 200 -0.305
  V1 1 6070.4
  V2 1 3212.9
  V3 1 742.2
  D 0.25  
  L0 0.75  
  L1 0.750  
  B 0.75  
  hl1 4398.9  
  P 6204.1  
  hl2 6114.2  
  k21 0.2806  
  hl3 6987.8  
  k22 0.5376  
  z1 0.4  
  k23 0.6955  
  k20 0.6128  
  k11 0.817  
  k12 1.411  
  k13 1.753  
  hv1 6927.7  
  hv2 12331.3  
  hv3 14716.8  
  k1f 1.5759  
  k2f 0.6128  
  k10 1.5759  
  F 1  
  z2 0.6  
  hf 8228  
  L3 0.75  
  L2 1.75  
  h0 5288.1  
  Q 10000  
  y11 0.4083  
  y12 0.5645  
  rec 0.2552  
       
Solution Variable Value f(x)
  x11 0.57902594925514 1.11E-16
  x12 0.39569120229748 9.99E-16
  x13 0.27186578944464 -1.11E-15
  x21 0.42097405074479 0
  x22 0.60430879770252 3.33E-16
  x23 0.72813421055536 -2.22E-16
  t1 186.378525897475 6.66E-16
  t2 200.526868526979 0
  t3 211.486095297259 1.110E-15
  tf 200.167501447086 0
  t0 169.064015709595 0
  V1 1.08137588467567 -3.64E-12
  V2 1.06683987591090 1.82E-11
  V3 1.04952829661125 -2.18E-11
  D 0.25  
  L0 0.83137588467567  
  L1 0.81683987591090  
  B 0.75  
  hl1 7385.230868740510  
  P 6204.081632653060  
  hl2 8258.041508211440  
  k21 0.51213933009160  
  hl3 8931.054498916270  
  k22 0.61698043668574  
  z1 0.4  
  k23 0.70841654598484  
  k20 0.61413708445032  
  k11 1.35469339962803  
  k12 1.58495637623241  
  k13 1.78094374630232  
  hv1 15505.2876150983  
  hv2 16469.3793109932  
  hv3 17305.1918210042  
  k1f 1.57879437332452  
  k2f 0.61413708445032  
  k10 1.10605654005438  
  F 1  
  z2 0.6  
  hf 8235.9303882639  
  L3 0.75  
  L2 1.79952829661125  
  h0 6290.0604895603  
  Q 10000  
  y11 0.78440263166929  
  y12 0.62715329410047  
  rec 0.49025164479331  
       
Additional information Some algorithms do not converge from initial guess 2