function PFRSpaceTime
% PFRSpaceTime.m
% 等溫管式反應器的管長計算
%
%   Author: HUANG Huajiang
%   Copyright 2003 UNILAB Research Center, 
%   East China University of Science and Technology, Shanghai, PRC
%   $Revision: 1.0 $  $Date: 2003/02/21 $

clear all
clc

k = 0.01;
T = 488.15;     % K
yA0 = 0.5;      % 進料氣中A的摩爾分率
P = 5;          % atm
R = 0.082;      % 理想氣體常數(shù)
CA0 = yA0*P/(R*T);  % mol/liter
epsilon = 1;
xAf = 0.8;

% the interval: [a, b], the step: d
a = 0;
b = xAf;
d = (b-1)/100; 

% 自適應Lobatto求積法(Adaptive Lobatto quadrature, high order)
I = quadl(@func,a,b,[],[],CA0,k,epsilon);
tau = CA0*I;
fprintf('\tSpace time: %.1f (s)',tau)

% ------------------------------------------------------------------
function f = func(xA,CA0,k,epsilon)  
CA = CA0*(1-xA)./(1+epsilon*xA);
rate = k*sqrt(CA);
f = 1./rate;