Sy. Bae et al., CO2, N-2 GAS SORPTION AND PERMEATION BEHAVIOR OF CHITOSAN MEMBRANE, The Korean journal of chemical engineering, 15(2), 1998, pp. 223-226
The sorption equilibria for CO2 and N-2 in dry chitosan membrane at 20
and 30 degrees C were measured by a pressure decay method. The steady
-state permeation rates for CO2 and N-2 in dry and wet (swollen with w
ater vapor) chitosan membranes at 20 and 30 degrees C were measured by
a variable volume method. The sorption equilibrium for N-2 obeyed Hen
ry's law, whereas that for CO2 was described apparently by a dual-mode
sorption model. This non-linear sorption equilibrium for CO2 could be
interpreted by the interaction of sorbed CO2 with the chitosan matrix
expressed as a reversible reaction. The logarithm of the mean permeab
ility coefficient for CO2 in dry chitosan membrane increased linearly
with upstream gas pressure. A linear increase of the logarithmic mean
permeability coefficient for CO2 with the pressure could be interprete
d in terms of a modified free-volume model. The mean permeability coef
ficient for N-2 in dry chitosan membrane only slightly increased with
upstream gas pressure. The permeabilities for CO2 and N-2 in wet chito
san membrane increased by 15 to 17 times and 11 to 15 times, respectiv
ely, as compared to those in the dry membrane.