Example 4-6 Calculating X in a Reactor with Pressure Drop  |POLVER05_3
d(X)/d(W) =     -raprime/Fao     #
d(y)/d(W) =    -alpha*(1+eps*X)/2/y    #
raprime =    -kprime*(1-X)/(1+eps*X)*y    #
kprime =    0.0266    #
Fao =   1.08   #
alpha =    0.0166    #
f =    (1+eps*X)/y    #
eps =    -0.15    #
rate =    -raprime    #
W(0)=0
X(0)=0
y(0)=1
W(f)=60