Page 69 - Pressure Swing Adsorption

44 PRESSURE SWING ADSORPTION FUNDAMENTALS OF ADSORPTION 45

i • 0
(1;1
i. 0 ~-------------'-'--'--------------,
0.' 'ca 3.65µm
De/re '3•10-'s·' 0
' •
- 0.6 0.8
. o.,
l o.6
0.2
E
' D
0 q 10 12 111 16 ta :rn 0.4
ti(mmi)
0
0.2

5 10 15 20 25 30 35
Jt isec )' 12
Figure 2.17 (Continued).

diffus10n equation takes the form:
2 iJ(J.,1 \
iJ0A _ [)_.Ju [ + --J
at - ( I - 8 - 0 ) ( I r (Ir (2.4 I)
A H

b
-2
10
0 200 ,oo 600 800 1000 1200 lllOO
Time (min}
with a similar ex11ression for component /J. These expressions arc used in the
modeling the dvnam1c behavior of the kincucally sdect1ve CMS adsorhents
(see Secl!on 5.2).
Partial
pressure step
Curve Sorbate T (K) {Torr) Deir~ (s-')
2.3.7 Macropore Diffusion
I 0, 193 6-225 2.6 K 10-s
2 N, 273 715-580 3.2 X 10- 6 Locai sorpt1on raic:
3 o, 193 470- 750 1.ox10-~
4 0, 273 250----110 4.1 X 10- 4 ac \ aa _ i 2 ac a c I
2
',at+ (l - ',,Tf - ,,D,\ R JR + aR 2 ) (2.42)
Figure 2.17 Expcnmcntai uptake curves {a) and (b) for 0 m the Bcrgbau-
2
Forsclrnng carbon molecular sieve at 193 K and (c) and N., in three different size
fractions ()!' 4A zcolitc crvstais. showmg conforniity with thC diffusion model. From If the equilibrium is linear (q* = Kc), this reduces to:
Ruthven 14 and Yuccl and Ruthvcn. 44
( 2 .43)