Page 199 - Elements of Chemical Reaction Engineering 3rd Edition

Sec. 4.4 Pressure Drop in Reactors 171

Following I. Mole balance:
the algorithm
In - out + generation = 0
FA/, - FAI,+Az + rAAcAz =
Dividing by Az and taking the limit as Az --+ 0 yields

In terms of conversion

(E4-8.1)

rA= -kCA= -k’C,pc(l-$) (E4-8.2)

(E4-8.3)
L I
& = yAO 6 = 1 x (1 + 1 - 1) = 1 (E4-8.4)
where

P
4’”- (E4-8.5)
Po
Noie that yAo (y with a subscript) represents the mole fraction and y alone represents
the pressure ratio, PIPo.
The variation in the dimensionless pressure, y, is given by incorporating the
variable y in Equation (4-24):

(E44.6)
1
The units of Po for this problem are kEWdm3.
The equations in
boxes are the key
equations used (E4-8.7)
in the ODE solver
program

(E4 8.8)
-
For a spherieal reactor
(E4-8.9)
i
w = pc(l -+)a R2z-i (E4-8.10)