ERI

 
Cinética                            Reactores Químico

           

%Programa para calcular as trajectorias de um CSTR politropo com reacção exotérmica A<-->B de 1ª ordem
% ex: gr(0,425)
%

function ni=gr(xx,yy)
global k0 Ea Ke0 Te teta Q Cp UA Text Ce dH V
V=3;Q=10;Te=280;Ce=1;UA=20;Text=293;k0=0.1*10^6;Ea=10000;
Ke0=100;dH=-4000;Cp=4.0;
teta=V/Q;
T=Te-5:750;
x=BMEes(T);
subplot(1,1,1);hold on;grid on
ylim([0 1]);
xlim([275 750]);
plot(T,x(1,:),'LineWidth',2,'Color',[0 0 0]);
plot(T,x(2,:),'LineWidth',2,'Color',[0 0 1]); % Balan?os em Est. Estacionario
plot(T,Xe(T),'LineWidth',2,'Color',[0.6 0.2 0]);
xo=xx;
To=yy;
tf=10;
[t,xT]=ode45(@BME,[0 tf],[xo To]);
plot(xT(:,2),xT(:,1),'g')
xlabel('T (K)');
ylabel('X');
title('\bf CSTR c/ reac??o exot?rmica de 1?ordem A \leftrightarrow B')
legend('BM','BE','Xeq.','Location','Best')
end

function dxTdt=BME(t,y)
global teta Te Text Cp UA V dH
x=y(1);
T=y(2);
k=k1(T);
K=Ke(T);
dxdt=-1/teta.*x+k.*(1-x-x./K);
dTdt=1./teta.*(Te-T)-k.*(1-x-x./K).*dH/Cp-UA/V/Cp.*(T-Text);
dxTdt=[dxdt;dTdt];
end

function resposta=Ke(y)
global Ke0 dH Te
T=y;
resposta=Ke0*exp(-dH/1.9872.*(1./T-1/Te));
end

function resposta=Xe(y)
T=y;
resposta=Ke(T)./(1+Ke(T));
end

function resposta=k1(y)
global k0 Ea
T=y;
resposta=k0*exp(-Ea/1.9872./T);
end
function resposta=BMEes(y)
global teta Q Cp Te UA Text Ce dH
T=y;
xm=Ke(T).*k1(T).*teta./(Ke(T)+k1(T)*teta.*(1+Ke(T)));
xe=((Q*Cp+UA).*T-Q*Cp*Te-UA*Text)/(Q*Ce*(-dH));
resposta=[xm;xe];
end

Published with MATLAB® 7.9