Abstract
Separation of light gaseous olefins from paraffin’s of the refinery process off-gasses has been traditionally performed by cryogenic distillation, which is a highly capital and energy intensive operation. This handicap creates an incentive for the investigation of alternative olefin/paraffin separation technologies. In this regard, membrane technology supposes a potential solution for process intensification. Previous works of our research group reported the use of facilitated transport composite membranes integrating the use of PVDF-HFP polymer, BMImBF4 ionic liquid and AgBF4 silver salt. In this type of membranes, the silver cations react selectively and reversibly with the olefin, allowing the separation via mobile and fixed carrier mechanisms. Ionic liquids were selected as membrane additives because in addition to their negligible vapor pressure that avoids solvent losses by evaporation, they provide stability to the metallic cation dissolved inside, and modify the structure improving the facilitated transport. This technology offers a commercial attractive separation alternative thanks to their modular form of operation, high values of selectivity and permeability and low operational costs. In the present work, propane/propylene permeation experiments involving the use ionic liquids and different membrane compositions were performed. Moreover, basing on the transport and equilibrium parameters previously obtained, a mathematical model description of the system will be proposed fitting the remaining parameters and allowing the design and optimization of the propane/propylene separation process at industrial levels.
Funding statement: Funding: This research was supported by the Spanish Ministry under the projects CTQ2012-31639 (MINECO, SPAIN-FEDER 2007–2013) and (CTM2013-44081-R).
References
1. RBN Energy [Internet]. On-purpose propylene via propane dehydrogenation. RBN Energy LLC. [Houston] [Cited 2015 December 21]. Available at: https://rbnenergy.comSearch in Google Scholar
2. Eldridge RB. Olefin/paraffin separation technology: a review. Ind Eng Chem Res 1993;32:2208–12.10.1021/ie00022a002Search in Google Scholar
3. Baker RW. Research needs in the membrane separation industry: looking back, looking forward. J Memb Sci 2010;362:134–6.10.1016/j.memsci.2010.06.028Search in Google Scholar
4. Faiz R, Li K. Olefin/paraffin separation using membrane based facilitated transport/chemical absorption techniques. Chem Eng Sci 2012;73:261–84.10.1016/j.ces.2012.01.037Search in Google Scholar
5. Das M, Koros WJ. Performance of 6FDA-6FpDA polyimide for propylene/propane separations. J Memb Sci 2010;365:399–408.10.1016/j.memsci.2010.09.029Search in Google Scholar
6. Fallanza M, Ortiz A, Gorri D, Ortiz I. Polymer-ionic liquid composite membranes for propane/propylene separation by facilitated transport. J Memb Sci 2013;444:164–72.10.1016/j.memsci.2013.05.015Search in Google Scholar
7. Noble RD. Generalized microscopic mechanism of facilitated transport in fixed site carrier membranes. J Memb Sci 1992;75:121–9.10.1016/0376-7388(92)80011-8Search in Google Scholar
8. Merkel TC, Blanc R, Ciobanu I, Firat B, Suwarlim A, Zeid J. Silver salt facilitated transport membranes for olefin/paraffin separations: carrier instability and a novel regeneration method. J Memb Sci 2013;447:177–89.10.1016/j.memsci.2013.07.010Search in Google Scholar
9. Ortiz A, Ruiz A, Gorri D, Ortiz I. Room temperature ionic liquid with silver salt as efficient reaction media for propylene/propane separation: absorption equilibrium. Sep Purif Technol 2008;63:311–18.10.1016/j.seppur.2008.05.011Search in Google Scholar
10. Ortiz A, Galán Sanchez LM, Gorri D, De Haan AB, Ortiz I. Reactive ionic liquid media for the separation of propylene/propane gaseous mixtures. Ind Eng Chem Res 2010;49:7227–33.10.1021/ie100576rSearch in Google Scholar
11. Fallanza M, Ortiz A, Gorri D, Ortiz I. Experimental study of the separation of propane/propylene mixtures by supported ionic liquid membranes containing Ag+-RTILs as carrier. Sep Purif Technol 2012;97:83–9.10.1016/j.seppur.2012.01.044Search in Google Scholar
12. Ortiz A, Galán LM, Gorri D, De Haan AB, Ortiz I. Kinetics of reactive absorption of propylene in RTIL-Ag+ media. Sep Purif Technol 2010;73:106–13.10.1016/j.seppur.2010.03.008Search in Google Scholar
13. Ortiz A, Gorri D, Irabien T, Ortiz I. Separation of propylene/propane mixtures using Ag+-RTIL solutions. Evaluation and comparison of the performance of gas-liquid contactors. J Memb Sci 2010;360:130–41.10.1016/j.memsci.2010.05.013Search in Google Scholar
14. Yampolskii Y, Pinnau I, Freeman B. Material science of membranes for gas and vapor separation. John Wiley: Chippenham, 2006.10.1002/047002903XSearch in Google Scholar
©2016 by De Gruyter
