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.
%
% Revised 8/13/2018

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


nc_As = 500;
c_Avect = linspace(0.995*p.c_Af, .002*p.c_Af, nc_As);
DelHvec = [-3e5, -2e5, -1e5, -0.5e5, 0, 5e4];
nH = length(DelHvec);
table(1:nH) = {zeros(nc_As,4)};

for j = 1: nH;
    DeltaH_R = DelHvec(j);
    tmp_table = zeros(nc_As,4);
    x0 = [1; p.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( @(x) st_st_cA(x, c_A, DeltaH_R, p), x0, opts);
        theta = x(1);
        T = x(2);
        conv = (p.c_Af - c_A)/p.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, c_A, DeltaH_R, p)
    theta = x(1);
    T     = x(2);
    k     = p.k_m*exp(-p.E*(1/T - 1/p.T_m));
    retval(1) = p.c_Af - (1 + k*theta)*c_A;
    retval(2) = p.U*theta*(p.T_a - T) + p.C_ps*(p.T_f - T) - ...
                    k*theta*c_A*DeltaH_R;