Polymer–ionic liquid composite membranes for propane/propylene separation by facilitated transport

Abstract In this work we propose the use of novel PVDF-HFP/BMImBF 4 –Ag + facilitated transport membranes to carry out the separation of olefin/paraffin gas mixtures. These membranes exhibit good thermal, chemical and mechanical stability, good separation properties and easy manufacturing. The effect of membrane composition was evaluated concluding that the membrane with 80% polymer-20% IL w/w shows the best compromise between separation properties and mechanical resistance. The separation performance of membranes containing different concentrations of Ag + in the range 0–80% w/w at temperatures between 293 and 323 K and different operational conditions has been evaluated. The facilitated transport membranes herein prepared provided very promising results when tested with 50/50%v/v C 3 H 8 /C 3 H 6 mixtures obtaining C 3 H 6 permeabilities up to 6630 barrer and C 3 H 8 /C 3 H 6 selectivities over 700, placing these membranes well above the Robeson upper bound for polymeric and inorganic membranes. Moreover, these membranes showed excellent stability during long-term experiments carried out for 10 days.

[1]  P. Izák,et al.  High ionic liquid content polymeric gel membranes: Correlation of membrane structure with gas and vapour transport properties , 2012 .

[2]  R. Mahajan,et al.  Pushing the limits on possibilities for large scale gas separation: which strategies? , 2000 .

[3]  Hideto Matsuyama,et al.  Separation of ethylene from ethane by supported liquid membranes containing silver nitrate as a carrier. , 1986 .

[4]  Shalu,et al.  Thermal stability, complexing behavior, and ionic transport of polymeric gel membranes based on polymer PVdF-HFP and ionic liquid, [BMIM][BF4]. , 2013, The journal of physical chemistry. B.

[5]  P. Izák,et al.  High Ionic Liquid Content Polymeric Gel Membranes: Preparation and Performance , 2011 .

[6]  A. B. Haan,et al.  Reactive Ionic Liquid Media for the Separation of Propylene/Propane Gaseous Mixtures , 2010 .

[7]  Inmaculada Ortiz,et al.  Room temperature ionic liquid with silver salt as efficient reaction media for propylene/propane separation: Absorption equilibrium , 2008 .

[8]  T. Kaghazchi,et al.  Separation of Propylene-Propane Mixture Using Immobilized Liquid Membrane via Facilitated Transport Mechanism , 2009 .

[9]  T. Lodge,et al.  Synthesis and Gas Separation Performance of Triblock Copolymer Ion Gels with a Polymerized Ionic Liquid Mid-Block , 2011 .

[10]  Masayoshi Watanabe,et al.  Macromolecules in Ionic Liquids: Progress, Challenges, and Opportunities , 2008 .

[11]  Kang Li,et al.  Olefin/paraffin separation using membrane based facilitated transport/chemical absorption techniques , 2012 .

[12]  A. Ismail,et al.  Fabrication of carbon membranes for gas separation--a review , 2004 .

[13]  E. Kamio,et al.  A facilitated transport ion-gel membrane for propylene/propane separation using silver ion as a carrier , 2013 .

[14]  I. Ortiz,et al.  Screening of RTILs for propane/propylene separation using COSMO-RS methodology , 2013 .

[15]  R. Eldridge,et al.  Olefin/paraffin separation technology: a review , 1993 .

[16]  Evidence for Parallel Pathways in the Facilitated Transport of Alkenes through Ag+-Exchanged Nafion Films , 1996 .

[17]  H. Kita,et al.  Permeation and separation properties of polyimide membranes to olefins and paraffins , 1996 .

[18]  A. B. Haan,et al.  Kinetics of reactive absorption of propylene in RTIL-AG+ media , 2010 .

[19]  Chang Kon Kim,et al.  New Insights into the Coordination Mode of Silver Ions Dissolved in Poly(2-ethyl-2-oxazoline) and Its Relation to Facilitated Olefin Transport† , 2002 .

[20]  K. Char,et al.  Effect of the polarity of silver nanoparticles induced by ionic liquids on facilitated transport for the separation of propylene/propane mixtures , 2008 .

[21]  Pei Li,et al.  PVDF/ionic liquid polymer blends with superior separation performance for removing CO2 from hydrogen and flue gas , 2012 .

[22]  Rong Wang,et al.  Pressure and temperature dependence of the gas-transport properties of dense poly[2,6-toluene-2,2-bis(3,4-dicarboxylphenyl)hexafluoropropane diimide] membranes , 2004 .

[23]  K. Char,et al.  Ionic liquid as a solvent and the long-term separation performance in a polymer/silver salt complex membrane , 2007 .

[24]  T. Lodge,et al.  ABA-triblock copolymer ion gels for CO2 separation applications , 2012 .

[25]  Matthias Wessling,et al.  An Adaptive Self‐Healing Ionic Liquid Nanocomposite Membrane for Olefin‐Paraffin Separations , 2012, Advanced materials.

[26]  Akira Ohkawa,et al.  Separation of propylene/propane mixture by a supported liquid membrane containing triethylene glycol and a silver salt , 2003 .

[27]  William J. Koros,et al.  Olefin/paraffin gas separations with 6FDA-based polyimide membranes , 2000 .

[28]  P. Izák,et al.  Gas transport properties of Pebax®/room temperature ionic liquid gel membranes , 2012 .

[29]  H. Kim,et al.  Role of Polymer Matrix in Polymer/Silver Complexes for Structure, Interactions, and Facilitated Olefin Transport , 2003 .

[30]  Marcos Fallanza,et al.  Experimental study of the separation of propane/propylene mixtures by supported ionic liquid membranes containing Ag+–RTILs as carrier , 2012 .

[31]  K. Char,et al.  Long-term separation performance of phthalate polymer/silver salt complex membranes for olefin/paraffin separation , 2005 .

[32]  Kang Li,et al.  Polymeric membranes for light olefin/paraffin separation , 2012 .