
329Heterogeneous Reactors
Rateoflossof inthegasphase
acrossthesection /
A
r
A
L
,kmols
=
Rateof transferof from thegasphaseto
theliquidphaseinth
A
eesection
A
GL→
,kmo
(4.119)
Writing the equations for the terms on either side of the above equation, we have
−= −
ε
dP Nsdz s
AA p
[( )]1
(4.120)
where R is the gas law constant and N
A
is the ux of A, whose equations are listed in Table
4.5. Rearranging Equation 4.120 and integrating between z = 0 and z = Z, we get
dz
RTSs
dP
N
Z
p
A
A
P
P
Af
AO
=−
−
0
1
υ
ε()
(4.121)
Finally, the design equation for the packed bed gas–liquid reactor is
Z
RTSs
dP
N
p
A
A
P
P
Af
AO
=−
−
∫
υ
ε()1
(4.122)
The appropriate equation for ux