Computing Gas Permeation Using the Complete Mixing Model

reject composition

0.25

ideal separation factor

10

pressure on feed side

80

pressure on feed side

20

Consider an equimolar binary mixture (composed of species

A

and

B

) fed to a gas permeation module. The feed rate

x

f

is equal to

1×

4

10

3

cm

(STP)/s

. This Demonstration computes the permeate composition

y

p

, the stage cut,

θ

, and the required membrane area,

a

(expressed in

2

cm

), for user-specified values of the desired reject composition, the ideal separation factor (i.e., the ratio of the permeabilities of the two species present in the feed mixture), pressure in cmHg on both the feed and the permeate sides of the membrane. For the computation of the area, two additional pieces of information are required: (1) the membrane thickness,

t

, chosen equal to

2.54×

-3

10

cm

and (2) the permeability of species

A

,



P

A

=50×

-10

10

3

cm

(STP)cms

2

cm

cmHg.