## Figure 4.22 (page 157):

### Molar flowrate of ethane, ethylene and NO versus reactor volume for ethane pyrolysis example.

## Code for Figure 4.22

Text of the GNU GPL.

### main.m

%% 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.
%
% This program solves the ethane pyrolysis text example with NO inhibitions.
%
% It was last edited 1/2/2002
global k P R1 T
%E in Joules, mass in grams, T in Kelvin, time in sec, volume in cm3
Components_1 = [' C2H6 = 1,',' NO = 2,',' C2H5 = 3,',' HNO = 4'];
Components_2 = [' H = 5,',' C2H4 = 6,', ' H2 = 7,'];
Ao = [1e14,3e14,3.4e12,1e12,1e13,1e12]';
Ea = [217600,165300,28500,0,200800,0]';
nu = [-1,-1,1,1,0,0,0
0,0,-1,0,1,1,0
-1,0,1,0,-1,0,1
0,-1,0,1,-1,0,0
0,1,0,-1,1,0,0
1,1,-1,-1,0,0,0];
R = 8.3144; %(J/gmole-K)
R1 = 82.057; %cc-atm/gmole-K
T = 1050; %K
P = 1.0; % atm
EXP = exp(-Ea/(R*T));
k = Ao.*EXP;
y1f = 0.95;
y2f = 0.05;
C1f = y1f*P/(R1*T); %gmole/cm3
C2f = y2f*P/(R1*T); %gmole/cm3
Qf = 600.0; %cc/sec
N1f = C1f*Qf; %gmole/sec
N2f = C2f*Qf;
Initial = [N1f,N2f,0,0,0,0,0]';
v = linspace(0, 1500, 200)';
opts = odeset ('AbsTol', sqrt (eps), 'RelTol', sqrt (eps));
[tsolver, solution] = ode15s(@rxrate,v,Initial,opts);
answer = [v solution];
%Components_1 = [' C2H6 = 1,',' NO = 2,',' C2H5 = 3,',' HNO = 4'];
%Components_2 = [' H = 5,',' C2H4 = 6,', ' H2 = 7,'];
plot (answer(:,1),[answer(:,2),answer(:,7),answer(:,3)]);
title ('Figure 4.22')

### rxrate.m

function dNdv = rxrate(v,x)
global k P R1 T
N1 = x(1);
N2 = x(2);
N3 = x(3);
N4 = x(4);
N5 = x(5);
N6 = x(6);
N7 = x(7);
Ntot = N1 + N2 + N3 + N4 + N5 + N6 + N7;
Ctot = P/(R1*T);
C1 = (N1/Ntot)*Ctot;
C2 = (N2/Ntot)*Ctot;
C3 = (N3/Ntot)*Ctot;
C4 = (N4/Ntot)*Ctot;
C5 = (N5/Ntot)*Ctot;
r1 = k(1)*C1*C2;
r2 = k(2)*C3;
r3 = k(3)*C1*C5;
r4 = k(4)*C2*C5;
r5 = k(5)*C4;
r6 = k(6)*C3*C4;
dNdv = zeros (7, 1);
dNdv(1) = -r1 - r3 + r6;
dNdv(2) = -r1 -r4 + r5 +r6;
dNdv(3) = r1 -r2 + r3 -r6;
dNdv(4) = r1 +r4 -r5 -r6;
dNdv(5) = r2 -r3 -r4 + r5;
dNdv(6) = r2;
dNdv(7) = r3;