Natural gas purification and olefin/paraffin separation using cross-linkable dual-layer hollow fiber membranes comprising β-Cyclodextrin

CO2/CH4 separation by means of Matrimid hollow fibre membranes

“…), or feed conditions required to obtain the final product with certain characteristics. triangles and diamonds refer to experimental data; circles refer to the literature data: Ayala et al [40]; Xiao et al [41]; Chan et al [42]; Staudt Bickel et al [43]; Peter et al [44]; Shao et al [45]; Hillock et Koros [46]; Suzuki et al [47]; Swaidan et al [48]; Sanders et al [49]; Vinh-Thang et al [50]; Nik et al [51]; Qui et al [52]; Hosseini et al [53]; Askari et al [54]; Scholes et al [37] For instance, if 60 % molar CO 2 recovery in the permeate is desired, the pressure ratio required is close to 2.5 in the case of the equimolecular mixture (CH 4 :CO 2 = 50:50), whereas it increases to 5 for the mixture with the higher concentration of methane (CH 4 :CO 2 = 70:30). Assuming this latter as reference mixture, for a pressure ratio of 5, the CO 2 concentration in the permeate can range between 50 to more than 80 to 90 % molar , according to the permeation number chosen with consequent changes on the recovery which can pass from 80 down to 40 % molar , respectively.…”

Flexible thermally treated 3D PIM-CD molecular sieve membranes exceeding the upper bound line for propylene/propane separation

“…3) which have similar sizes with C 3 H 6 and C 3 H 8 , the transport channels resulted from CD's decomposition may possess the appropriate characteristics to discriminate C 3 H 6 and C 3 H 8 , thus improving the gas pair selectivity. [47][48][49] In other words, the decomposition of thermal liable b-CD at high temperatures would generate free radicals and effectively accelerate the self-cross-linking reaction of nitrile to form triazine rings and pull the polymer chains closely Fig. 8 Comparison of the pure and mixed gas performance of the thermally treated PIM membranes at 35 C (lines are drawn to guide the eyes).…”

Correlation between Functional Group and Formation of Nanoparticles in PEBAX/Ag Salt/Al Salt Complexes for Olefin Separation

“…Therefore, olefin/paraffin separation has been so important process in petrochemical industry. [4,5] The olefin/paraffin separation has been accomplished nowadays by cryogenic distillation. [6][7][8] However, distillation processes demand large amounts of energy and equipment costs due to the chemical similarity between the vapor pressure of olefin and paraffin gas.…”

“…[14,15] The membrane technology has offered the advantages of low energy requirements, capital investment, installation space and operating costs. [4] In particular, polymer membranes have become an attractive alternative to traditional separation methods because of several advantages such as good mechanical stability, low cost and ease of processing [4,12] Among them, the membrane method using facilitated transport concept has been concentrated. [10,[16][17][18] Ag ions could coordinate reversibly with olefins such as propylene and were known as effective olefin carrier.…”