
364 Green Chemical Engineering
The net rate of conversion of A in the dense phase is
rk
z
A
d
Ad dd
=
ρε ∆
(4.230)
As the dense phase in contact with the bubble phase is assumed to have attained steady
state
A
b
A
d
=
and equating Equations 4.229 and 4.230, we get
ka CC
gb Ab Ad dd Ad
(4.231)
Solving Equation 4.231 for C
Ad
, we get
C
kaC
ka k
Ad
gb Ab
gb dd
=
+
ρε
(4.232)
Substituting Equation 4.232 for C
Ad
in Equation 4.230, we get the overall global rate of
transfer of A from the bubble phase to the dense phase in the section as
r
ka k
sdz
A
Ab
gb dd
=
+[( )( )]
11//ρε
(4.233)
Taking a molal balance of A in the bubble phase across the section, we get ...