| abstract |
The present invention discloses a new type of polyimide membranes including hollow fiber and flat sheet membranes with high permeances for air separations and a method of making these membranes. The new polyimide hollow fiber membranes have O 2 permeance higher than 300 GPU and O 2 /N 2 selectivity higher than 3 at 60° C. under 308 kPa for O 2 /N 2 separation. The new polyimide hollow fiber membranes also have CO 2 permeance higher than 1000 GPU and single-gas selectivity for CO 2 /CH 4 higher than 20 at 50° C. under 791 kPa for CO 2 /CH 4 separation. |