Handbook of Solvents - George Wypych - ChemTech - Ventech!

696 George Wypych
A/l, mol s -1 m -2 Pa -1 or B/l, mol s -1 m -2 Pa -2
35
30
25
20
15
10
5
A/l
B/l
0
0 50 100 150 200 250
Evaporation time, min
Figure 12.1.26. Pervaporation transport parameters:
A/l (liquid transport) and B/l (vapor transport) vs.
evaporation time during membrane preparation from
aromatic polyamide. [Data from A Yamasaki,
R K Tyagi, A Fouda, T Matsuura, J. Appl. Polym. Sci.,
57, No.12, 1473-81 (1995).]
Flux, g m -2 h -1
14
12
10
8
6
4
2
0
0 0.02 0.04 0.06 0.08 0.1
Triclene in feed, wt%
Figure 12.1.28. Effect of triclene concentration in feed
solution on its pervaporation flux through acrylic
membrane. [Data from M Hoshi, M Kobayashi,
T Saitoh, A Higuchi, N Tsutomu, J. Appl. Polym. Sci.,
69, No.8, 1483-94 (1998).]
Separation factor
Hexane in permeate, wt%
1000
200
0 0.2 0.4 0.6 0.8 1
with a mixture of non-solvents: xylene and acetic acid. In addition, large amounts of acetone
were used in the coagulation bath. A more recent process avoided environmental problems
by using tetrahydrofuran and γ-butyrolactone in a process in which water only is used in the
coagulating bath (membrane quality remained the same). 10
800
600
400
Solubility of solvent in water, wt%
Figure 12.1.27. Separation factor vs. solubility of
solvents in water. [Adapted, by permission, from
M Hoshi, M Kobayashi, T Saitoh, A Higuchi,
N Tsutomu, J. Appl. Polym. Sci., 69, No.8, 1483-94
(1998).]
100
80
60
40
20
0
0 20 40 60 80 100
Hexane in feed, wt%
Figure 12.1.29. Effect of hexane concentration in feed
solution on its concentration in permeate through
acrylic membrane. [Data from M Hoshi,
M Kobayashi, T Saitoh, A Higuchi, N Tsutomu,
J. Appl. Polym. Sci., 69, No.8, 1483-94 (1998).]