Figure 6.6:

Steady-state temperature versus residence time for different values of the heat of reaction.

Code for Figure 6.6

Text of the GNU GPL.

main.m


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% Copyright (C) 2001, James B. Rawlings and John G. Ekerdt
%
% This program is free software; you can redistribute it and/or
% modify it under the terms of the GNU General Public License as
% published by the Free Software Foundation; either version 2, or (at
% your option) any later version.
%
% This program is distributed in the hope that it will be useful, but
% WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
% General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program; see the file COPYING.  If not, write to
% the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
% MA 02111-1307, USA.

global k_m T_m E c_Af c_A C_ps T_f DeltaH_R U T_a
%
% multiplicity parameters
%
% units are kmol, min, kJ, K, m^3
%
%
k_m      = 0.001;
T_m      = 298;
E        = 8000;
c_Af     = 2;
C_p      = 4;
rho      = 1000;
C_ps     = rho*C_p;
T_f      = 298;
T_a      = T_f;
U        = 0;


nc_As = 500;
c_Avect = linspace(0.995*c_Af, .002*c_Af, nc_As);
DelHvec = [-3e5, -2e5, -1e5, -0.5e5, 0, 5e4];
nH = length(DelHvec);
table(1:length(DelHvec)) = {zeros(nc_As,4)};
for j = 1: nH;
  DeltaH_R = DelHvec(j);
  tmp_table = zeros(nc_As,4);
  x0=[1; T_f];
  for i = 1: nc_As
    c_A = c_Avect(i);
    opts = optimset ('MaxFunEvals', 2000*numel(x0), ...
                     'MaxIter', 500*numel(x0));
    [x, fval, info] = fsolve('st_st_cA', x0, opts);
    theta = x(1);
    T     = x(2);
    conv     = (c_Af - c_A) / c_Af;
    tmp_table(i,:) = [theta, T, conv, info];
    x0=x;
  end
  table(j) = {tmp_table};
end

save st_st.dat table;

if (~ strcmp (getenv ('OMIT_PLOTS'), 'true')) % PLOTTING
  hold on
  for i = 1:nH
    semilogx(table{i}(:,1),table{i}(:,3))
  end
  hold off
  axis([1,1e5,0,1]);

  figure()
  hold on
  for i = 1:nH
    semilogx(table{i}(:,1),table{i}(:,2))
  end
  hold off
  axis([1,1e5,260,460]);
% TITLE st_st_T
end % PLOTTING

st_st_cA.m


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function retval = st_st_cA(x)
  global k_m T_m E c_Af c_A C_ps T_f DeltaH_R U T_a
  theta = x(1);
  T     = x(2);
  k     = k_m*exp(-E*(1/T - 1/T_m));
  retval(1) = c_Af - (1+k*theta)*c_A;
  retval(2) = U*theta*(T_a - T) + C_ps*(T_f - T) - k*theta*c_A*DeltaH_R;