Membrane Gas Separation

9.3.2
Experimental Setup 
The experimental setup APG - 1 (Figure 9.6 ), described elsewhere [25] , was used for 
measurement of the nitrogen, oxygen and air permeability. For pure gases and gas mixture 
permeation experiments, compressed gas cylinders of O 
2
, N 
2
, and air (21% O 
2
/79% N 
2
) 
were supplied by Praxair. This setup was furnished with a gas chromatograph HP 5890A, 
which let us measure the oxygen and nitrogen concentration in the permeate. The main 
part of this experimental setup was a diffusive chamber, where the membrane in the 
form of a disc was placed. The membrane effective area was 19.63 cm 
2
. This setup was 
used for a low - pressure (from 0.1 to 1.0 MPa) analysis of gas permeation. After installa-
tion of membrane in the diffusive chamber, we have rinsed this chamber with an appro-
"
a
"
"
b
"
1
C
1
(x,t)
0,8
0,6
0,4
0,2
0
1
C
2
(x,t)
0,8
0,6
0,4
0,2
0
0,2
0,4
0,6
0,8
1
0
x
0,2
0,4
0,6
0,8
1
0
x
t
1
t
2...
t
n
t
1
t
2...
t
n
Figure 9.5 Concentration profi les – solutions of Equation (9.17) with conditions (Equation 
 9.15 ) for constant diffusion coeffi cients D
11
= 1, D
12
= 0.13, D
21
= 0.14, D
22
= 1.1, and 
drift coeffi cient w = 10, for different times: (a) concentration profi les for component 1 of 
the mixture; (b) concentration profi les for component 2 of the mixture. Reprinted with 
permission from Journal of Membrane Science, Studies on the air membrane separation in 
the presence of a magnetic fi eld by Anna Strzelewicz and Zbigniew J. Grzywna, 294, 1 – 2, 
60 – 67, Copyright (2007) Elsevier Ltd

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Air Enrichment by Polymeric Magnetic Membranes
167
DCP
PC
G
F
DRF
GC
M
Figure 9.6 Scheme of the experimental setup APG - 1. G, gas cylinder; F, fl owmeter; DRF, 
digital registrar of fl owmeter; PC, pressure controller; DCP, digital controller of pressure; 
M, diffusive chamber; GC, gas chromatograph
priate gas. Then, between the high - and low - pressure part of a chamber, a suitable pressure 
difference was established (0.3 – 0.7 MPa) and controlled by an electronic pressure meter 
and controller EL - press P - 506C (the error of the measurement of step change in a feed 
pressure, about 0.2 s, is very low, and repeatable, for all the measurements). After that, 
the fl ow rate of the permeate was recorded using a Flow - Bus fl owmeter (with a range 
0 – 3 ml/min) with a computer data acquisition. All measurements were carried out at 
room temperature. Using fl ow rate data, air enrichment and transport coeffi cients were 
calculated.