Biomedical Engineering Reference
In-Depth Information
Thus, the volume of the reactor by integration.
2
1 f
A
1 f
A
f
Ae
f
Ae
Z
Z
Q
0
k
1
þ
f
A
1 f
A
Q
0
k
V ¼
d
f
A
¼
d
f
A
0
0
f
Ae
Z
2
1 f
A
1
d
f
A
(E5-2.8)
Q
0
k
¼
0
k
2ln
1 f
Ae
f
Ae
Q
0
¼
Where the volumetric flow rate can be computed from the reactor inlet conditions based on
ideal gas law,
F
A
0
RT
0
p
0
¼
m
0
RT
0
p
0
M
A
Q
0
¼
(E5-2.9)
1. The required volume of the PFR can thus be computed using Eqn
(E5-2.8)
. First, we need
to find the volumetric flow rate at the reactor inlet. Since the mass flow rate is given, as
well as the pressure and temperature. Using Eqn
(E5-2.9)
Q
0
¼
m
0
RT
0
1
kg
=
s
8314
J
=ð
kmol
$
K
Þ1000
K
p
0
M
A
¼
2 10
5
Pa
ð2 12:011 þ 6 1:00794Þ
kg
=
kmol
¼ 1:38246
m
3
=s
Using
Eqn (E5-2.8)
, we obtain
k
2ln
1 f
Ae
f
Ae
¼
1:38246
m
3
Q
0
=
s
V ¼
=minÞ
½2lnð1 0:2Þ0:2
0:254min
1
=60ð
s
¼ 80:43
m
3
2. Residence time for the reaction mixture passing through the differential volume as shown
in
Fig. E5-2
can be determined by
d
V
Q
d
t ¼
(E5-2.10)
Substituting
Eqns (E5-2.2) and (E5-2.3)
into
Eqn (E5-2.10)
, we obtain
d
V
Q
¼ F
A
0
d
f
A
1
Q
¼ F
A
0
d
f
A
d
f
A
kF
A
d
t ¼
kC
A
kQC
A
¼ F
A
0
which leads to
1
k
d
f
A
1 f
A
d
t ¼
(E5-2.11)
Search WWH ::
Custom Search