Toluene and n-heptane sorption in Matrimid® asymmetric hollow fiber membranes

Antiplasticization and plasticization of Matrimid® asymmetric hollow fiber membranes. Part B. Modeling

“…2 and 3 and corresponding dual mode parameters for both gases are given in Table 3. A general explanation of the so-called dual mode sorption model is available in our recent study [15]. The sorption capacity of the annealed fiber sample is substantially lower than that of the non-annealed sample due to the significant reduction in excess free volume, similar to the case of toluene and n-heptane in our recent work [15].…”

“…A general explanation of the so-called dual mode sorption model is available in our recent study [15]. The sorption capacity of the annealed fiber sample is substantially lower than that of the non-annealed sample due to the significant reduction in excess free volume, similar to the case of toluene and n-heptane in our recent work [15]. Annealing of the fiber sample results in a slight increase in the Henry's law constant, k D , a substantial reduction in the Langmuir capacity constant, C H , and an increase in the Langmuir affinity constant, b.…”

“…For non-annealed Matrimid ® fibers, substitution of the dual mode sorption parameters for CO 2 and CH 4 given in Table 3, respectively, and those for toluene given in our previous work [15] and the dual mode trans- Table 4. port parameters given in Table 4 into Eq.…”

“…In this application, the diluent weight fraction, w, used in Eqs. (14), (15) and (17), is the average diluent weight fraction across the membrane. Since the downstream side of the membrane is maintained under vacuum in these experiments, the average diluent weight fraction through the membrane is estimated as equal to half the diluent weight fraction at the upstream side of the membrane.…”

Natural gas sweetening—the effect on CO2–CH4 separation after exposing a facilitated transport membrane to hydrogen sulfide and higher hydrocarbons

“…The CO 2 conditioning effects on polycarbonates were documented in 80 0 s by several researchers [5][6][7][8][9]. Koros and Paul 0 s groups [10][11][12][13] and White et al [14] have studied extensively the influence of certain heavy hydrocarbons (toluene, n-hexane, n-heptane) mainly on the CO 2 /CH 4 performance of polyimide, carbon molecular sieve and mixed matrix membranes. A recent study showed that certain heavy hydrocarbons may lead to the plasticization of glassy polyamides whereas lower concentrations of such larger impurities may lead to antiplasticization [15].…”