A. Ito et al., Permeation of wet CO2/CH4 mixed gas through a liquid membrane supported onsurface of a hydrophobic microporous membrane, SEP PURIF T, 24(1-2), 2001, pp. 235-242
A double-layer liquid membrane was proposed where a supported liquid membra
ne of diglycolamine (DGA) or triethylene glycol (TEG) was supported on the
surface of another microporus membrane, a Durapel membrane(Millipore). by i
ts hydrophobicity, This surface supported liquid membrane was used for the
separation of CO2 from a wet CO2/CH4 mixed gas. The liquid membrane of this
construction is durable up to a transmembrane pressure of 250 kPa. That is
. the liquid membrane is applicable for the vacuum mode permeation and pres
surized permeation mode. Permeation experiments through the DGA liquid memb
rane with a 25 mum thickness shows that the CO2 permeability was 30-100 Bar
rer with a CO2/CH4 separation factor of 40-100. The CO2 permeability was co
mparable to polymer membranes. The partial pressure dependency of the CO2 p
ermeability may imply the existence of facilitated transport during the vac
uum mode permeation. A comparison of the dry feed and wet feed experiments
using the TEG liquid membrane showed that there was no large effect of the
water vapor in the feed on the selectivity and permeabilities. (C) 2001 Els
evier Science B.V. All rights reserved.