Page 172 - Elements of Chemical Reaction Engineering 3rd Edition

1 44 Isothermal Reactor Design Chap. 4

mol
The entering volumetric flow rate of stream A, with CAo, = 1. - dm3 before
mixing, is
F.0 - 7.67 lb mol/min = 7.67
UAO = - ft3
-
CAol 1 Ib mol/ft3 min
From the problem statement

uBO = uAO
The total entering volumetric flow rate of liquid is

uo = uA0 + uB0 = 15.34 ft' (7.24 dm3/s)
rnin
5. Substituting in Equation (E4-2.4), recalling that k = 0.311 min-', yields
ft3 0.8
v=-- 'Ox - 15.34- ;= 197.3 ft3
k(l -X) min (0.311 min-*)(l -0.8)
= 1480 gal (5.6 m3)
A tank 5 ft in diameter and approximately 10 ft tall is necessary to achieve
80% conversion.
6. CSTRs in parallel. For two 800-gal CSTRs arranged in parallel with 7.67
ft'/min (vo/2 ) fed to each reactor, the conversion achieved can be calculated
from
x=- zk (E4-2.5)
1 +zk

7 67 ft*/min

15.34 ft'lmin x = 0.81
c D

7.67 fta/min

-

0.81.
x

Figure E4-2.2 CSTRs in parallel