Environmental Engineering Reference
In-Depth Information
Here, denotes the maximum amount adsorbed in the micropores, and denotes
themonolayer capacity of the mesopore surface. For the standard adsorption iso-
therm measuredon a non-porous reference adsorbent, we have:
�
p
�
a
p
ƒ
„
s
0
a
=
(
(31)
s
a
0.4
s
Here, is the relative surface coverage for a non-porous reference adsorbent, isthe
amount adsorbed on the surface of this reference adsorbent at relative pressure
denotes the monolayer capacity evaluated from the standard adsorption isotherm,
and denotes the amount adsorbed on the surface of the reference solid at relative
pressure and we have:
�
p
�
�
p
�
0
a
=
a
q
+ ha
(32)
ƒ
p
„
ƒ
p
„
mi
mi
s
0
0
aa
a
0
(0.4)
(33)
h=
me
s
0
s
Kelvin-type equation is usually used to relate the capillary condensation pressure
to the radius of cylindrical pores:
2
g
V
�
p
�
�
p
�
r
=
+
t
ƒ
p
„
ƒ
p
„
(34)
��
€
ƒ„
p
0
0
RT
ln ln
0
p
This comparison involved t-curves proposed by Harkins and Jura:
0.5
-
13.99
p
�
�
-
t
=
0.1
p
ƒ
„
-
(35)
��
p
p
0
0.034
−
log
0
-
€
ƒ„
and Halsey model pressure
0.333
-
−
5
�
p
�
-
=
0.354
p
ƒ
„
-
��
p
p
(36)
0
ln ln
0
-
€
ƒ„
where t(p/p
o
) is the statistical film thickness (in nm) for nitrogen adsorbed on the
carbon surface and p/p
o
is the relative pressure. It was shown that the applicabil-
ity of the Barrett, Joyner and Halenda (BJH) computational method based on the
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