Pure- and mixed-gas propylene/propane permeation properties of spiro- and triptycene-based microporous polyimides

Abstract

Cite this article as: Ramy J. Swaidan, Bader Ghanem, Raja Swaidan, Eric Litwiller, Ingo Pinnau, Pure-and mixed-gas propylene/propane permeation properties of spiro-and triptycene-based microporous polyimides, Journal of Membrane Science, http://dx.doi.org/10. 1016/j.memsci.2015.05.044 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. sieving behavior in membrane-based separation of gas/gas pairs. In this work, the effects of systematically increasing intra-chain rigidity on the propylene/propane separation properties were compared for PIM-PIs made from 2,3,5,6-tetramethyl-1,4-phenylene diamine (TMPD) and (i) spiro-centered dianhyride (SPDA-TMPD or PIM-PI-1) and (ii) 9,10-diisopropyltriptycene-based dianhydride (TPDA-TMPD or KAUST PI-1). Pure-gas experiments at 2 bar and 35

Enhanced propylene/propane separation by thermal annealing of an intrinsically microporous hydroxyl-functionalized polyimide membrane

“…By designing selective free volume into the polymer structure PIMs have been shown to simultaneously boost permeability and gas/gas selectivity. Recently, our group reported the performance of highly permeable triptycene (KAUST-PI-1)-and spirobisindane (PIM-PI-1)-based polyimides for propylene/propane separation [29]. KAUST-PI-1 exhibited a C 3 H 6 /C 3 H 8 selectivity of 16 with the highest C 3 H 6 permeability of any polyimide reported to date of 817 Barrer, positioning it well above the experimentally observed upper bound.…”

Adsorption Equilibria of Propylene and Propane on Zeolites and Prediction of Their Binary Adsorption with the Ideal Adsorbed Solution Theory

“…2−6 This separation becomes challenging because propylene and propane molecules have very similar properties, for example, close boiling point (−42 and −47.6°C), molecular weight (44 and 42 g/mol, respectively), polarizability (6.29 and 6.26 × 10 −24 cm 3 ), and kinetic diameter (4.0 and 4.3 Å), respectively. A number of alternative separation processes have been proposed including membrane separation using highly selective membranes, 7 absorption, 8 adsorption 9 and its variants such as adsorption−distillation hybrid systems, 10,11 pressure swing adsorption (PSA) or vacuum swing adsorption (VSA). 3,12−16 Many adsorbents have been reported in the literature for propylene−propane separation including metal organic frameworks (MOFs), 13 zeolites, 6,14−18 Na-ETS-10, 19 and π-complexation adsorbents.…”

Improved gas transport properties of polyurethane–urea membranes through incorporating a cadmium‐based metal organic framework

“…Gas permeability was calculated using: where P is the permeability in barrer (1 barrer = 10 −10 cm 3 STP .cm/cm 2 .s.cmHg), V is the downstream chamber volume (cm 3 ), A is the effective membrane area (cm 2 ), l is the membrane thickness (cm), T is the feed temperature (K), dp(t) / dt is the rate of change of the downstream pressure at when the pressure increases with time almost linearly, and P 0 is the feed pressure. Diffusion coefficient ( D , cm 2 /s) was calculated using the time‐lag method: where θ is the time lag (s) and the intercept obtained from extrapolating the linear region of the p(t) vs the time. The solubility coefficient ( S ) (cm 3 STP / cm 3 .cmHg) was calculated using: and the ideal A/B selectivity using: …”

“…Diffusion coefficient ( D , cm 2 /s) was calculated using the time‐lag method: where θ is the time lag (s) and the intercept obtained from extrapolating the linear region of the p(t) vs the time. The solubility coefficient ( S ) (cm 3 STP / cm 3 .cmHg) was calculated using: and the ideal A/B selectivity using: …”

“…Gas composition of the permeate was detected using gas chromatography (GC‐2014, Shimadzu). The separation factor was calculated using: where x and y are the mole fractions of the components in the feed and permeate streams, respectively. The mixed gas permeability was calculated using: …”