Hm. Ettouney et O. Majeed, TRANSPORT AND PERMEATION PROPERTIES OF A TERNARY GAS-MIXTURE IN A MEDIUM-SIZE POLYSULFONE HOLLOW-FIBER PERMEATOR, Separation science and technology, 31(11), 1996, pp. 1573-1596
Permeation properties were analyzed for a mixture of CO2, O-2, and N-2
in a medium-size polysulfone hollow fiber permeator with a net permea
tion area of 4.22 m(2). Measurements were conducted as a function of f
eed composition, reject flow rate, and feed pressure. Results included
variations in species permeability, separation factor, permeate enric
hment, reject depletion, and stage cut as a function of system paramet
ers. Variations in permeation properties show strong dependence on fee
d composition, reject flow rate, and feed pressure. Permeability of ca
rbon dioxide was higher at larger feed pressures and higher carbon dio
xide content in the feed stream. Effect of increasing the reject flow
rates on the permeability of carbon dioxide was affected by the system
pressure and the carbon dioxide content in the feed stream. At low pr
essures, increase of the reject flow rate resulted in a decrease of ca
rbon dioxide permeablity. The opposite behavior was obtained at higher
feed pressures. Increase of the reject flow rate reduced the gas resi
dence time within the permeator. Increase of reject flow rate reduced
species residence within the permeator and in turn increased resistanc
e to species transport within the permeator. However, higher system pr
essures and carbon dioxide content in the feed stream resulted in larg
er levels of membrane plasticization, which increased the permeation r
ates of all species. The combined effect of reducing the species resid
ence time within the permeator and the level of membrane plasticizatio
n favored the permeation of carbon dioxide versus the other two specie
s. Variations in other permeation properties, which include oxygen and
nitrogen permeabilities, stage cut, permeate enrichment in carbon dio
xide, and reject depletion in carbon dioxide, were also explained in t
erms of resistances encountered within the permeator and the membrane.