Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9685007 | Journal of Membrane Science | 2005 | 9 Pages |
Abstract
We have determined the effect of temperature on intrinsic permeation properties of 6FDA-Durene/1,3-phenylenediamine (mPDA) 50/50 copolyimide dense film and fabricated high performance hollow fiber membranes of the copolyimide for CO2/CH4 separation. The hollow fiber membranes were wet-spun from a tertiary solution containing 6FDA-Durene/mPDA (PI), N-methyl-pyrrolidone (NMP) and tetrahydrofuran (THF) with a weight ratio of 20:50:30 at different shear rates within the spinneret. We observed the following facts: (1) the CO2/CH4 selectivity of the copolyimide dense film decreased significantly with an increase in temperature; (2) the performance of as-spun fibers was obviously influenced by the shear rate during spinning. For uncoated fibers, permeances of CH4 and CO2 decreased with increasing shear rate, while selectivity of CO2/CH4 sharply increased with shear rate until the shear rate reached 2169Â sâ1 and then the selectivity leveled off; (3) After silicone rubber coating, permeances of CH4 and CO2 decreased, the selectivity of CO2/CH4 was recovered to the inherent selectivity of its dense film. Both the permeances and selectivity with increasing shear rate followed their same trends as that before the coating; (4) there was an optimal shear rate at which a defect-free fiber with a selectivity of CO2/CH4 at 42.9 and permeance of CO2 at 53.3Â GPU could be obtained after the coating; and (5) the pressure durability of the resultant hollow fiber membranes could reach 1000Â psia at room temperature.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Filtration and Separation
Authors
Jian-Jun Qin, Tai-Shung Chung, Chun Cao, R.H. Vora,