Effects of hydrocarbon and water impurities on CO2/CH4 separation performance of ester-crosslinked hollow fiber membranes

Thin-skinned intrinsically defect-free asymmetric mono-esterified hollow fiber precursors for crosslinkable polyimide gas separation membranes

“…N-methylpyrrolidone its low volatility, low toxicity and high boiling point. In addition, to the dope to promote skin layer used to move the dope composition near to primary non-solvent, ethanol was process by balancing volatility and promotion of phase separation to offset the volatile solvent, THF 6 well-described earlier [24,38]. Fig.…”

“…The PDMC contains both carboxylic acid groups and ester groups, which form a crosslinked polymer network after crosslinking. This structure reduces the polymer chain mobility and stabilizes the polymer against aggressive feed streams, such as high CO2 partial pressures and high-level hydrocarbon contaminants contaminates [35,38]. Details about the crosslinking and characterization of The spinning polymer dope consists of polymer, solvent and non phase solution.…”

“…To suppress the CO2 plasticization, the hollow fibers can be subsequently crosslinked. Details on the development and characterization of crosslinked hollow fibers for natural gas separations were reported in the authors' other papers [24,38,41]. The high-flux crosslinked membranes are industrially preferred for natural gas separation under challenging feed streams, such as high CO2 partial pressure and/or high-level hydrocarbon impurities.…”

Physical aging in carbon molecular sieve membranes

“…Clearly, properties of polymeric membranes may be affected by contaminants or penetrant induced plasticization [37][38][39][40], etc. This fact notwithstanding, ''aging'' in polymeric membranes generally refers to physical aging in non-equilibrium glassy polymers undergoing physical rearrangements to approach an equilibrium state.…”

Molecularly Designed Stabilized Asymmetric Hollow Fiber Membranes for Aggressive Natural Gas Separation

“…Thes lightly lower permeance and selectivity presumably reflects free volumes filling by the heptane. [13] This negative effect on permeance is more significant with the presence of toluene,w ith up to 29 %l oss of permeance for the crosslinked TFM-PI-CF 3 fiber in the feed of 50/50 CO 2 /CH 4 mixtures containing 250 ppm heptane and 250 ppm toluene at 35 8 8Ca nd 55 bar.M oreover,e ven in this very aggressive feed, we did not observe the plasticization, and meanwhile a CO 2 =CH 4 remained above 30, while the non-cross-linked TFM-PI-CF 3 fiber showed at ypical plasticization behavior with permeance upswing at higher feed pressure ( Figure S14). Impressively,w ef ound the non-cross-linked fiber could maintain a CO 2 =CH 4 > 35 even though at the highest pressure of 55 bar, despite minor plasticization being apparent.…”