Effects of Ionic Liquid Blending in Polymeric Membrane: Physical Properties and Performance Evaluation

2014 ◽  
Vol 625 ◽  
pp. 680-684 ◽  
Author(s):  
Dzeti Farhah Mohshim ◽  
Hilmi Mukhtar ◽  
Zakaria Man

— Polymeric membranes have been extensively used in membrane gas separation process. Nowadays, peoples are modifying the membrane by many ways like coating with ionic liquids to further enhance the membrane separation performance. In this project, ionic liquid modified polymeric membranes (ILMPM) have been successfully developed by blending the ionic liquids with the polymer via solvent evaporation method. The ionic liquid used was 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide, ([emim][Tf2N]) and for comparison purpose, the compositions were varied at 10 and 20 wt/wt%. In general, the blending of [emim][Tf2N] and PES has produced dense membrane with miscible mixture without any phase separation. It was observed that, the CO2permeance of ILMPM has been improved about 271% as compared to the pure PES membrane. However, the CO2permeance decreased with increasing operating pressure, yet the ILMPM CO2permeance still higher than CO2permeance of pure PES membrane. In addition, the CO2/CH4separation performance has greatly increased about 162% as the IL composition is increased. This initial study has proven that IL helps to enhance of CO2permeation and improve selectivity.

2013 ◽  
Vol 594-595 ◽  
pp. 18-23 ◽  
Author(s):  
Dzeti Farhah Mohshim ◽  
Hilmi Mukhtar ◽  
Zakaria Man

Selected ionic liquids are known to enhance the absorption of CO2 for CO2 removal purpose. In the idea to improve the membrane separation performance for natural gas sweetening, ionic liquid modified polymeric membranes were fabricated by using polyethersulfone (PES) and blended with different composition of ionic liquid which are 5 wt% and 15 wt%. Each fabricated membranes were prepared and dried under solvent evaporation at 90°C. Dense structure observed from FESEM analysis indicated the miscible blends of ionic liquid and PES. TGA analysis showed all fabricated membranes are still containing solvent and this resembles that membrane drying period is still insufficient. All fabricated membranes were tested with ideal gas permeation test. From the result, the addition of ionic liquid has enhanced the ideal CO2 pemeance about 150% as compared to pure PES membrane. The ideal CO2/CH4 selectivity was also increase about 85% from the base but however, the separation index is still considered low and this may due to the presence of the solvent. This preliminary result has confirmed that the blending of ionic liquid with pure PES membrane has technically improved the membrane separation performance.


2021 ◽  
Vol 28 (5) ◽  
Author(s):  
Fadel Abdul Hadi Juber ◽  
Zeinab Abbas Jawad ◽  
Bridgid Lai Fui Chin ◽  
Swee Pin Yeap ◽  
Thiam Leng Chew

AbstractCarbon dioxide (CO2) emissions have been the root cause for anthropogenic climate change. Decarbonisation strategies, particularly carbon capture and storage (CCS) are crucial for mitigating the risk of global warming. Among all current CO2 separation technologies, membrane separation has the biggest potential for CCS as it is inexpensive, highly efficient, and simple to operate. Polymeric membranes are the preferred choice for the gas separation industry due to simpler methods of fabrication and lower costs compared to inorganic or mixed matrix membranes (MMMs). However, plasticisation and upper-bound trade-off between selectivity and permeability has limited the gas separation performance of polymeric membranes. Recently, researchers have found that the blending of glassy and rubbery polymers can effectively minimise trade-off between selectivity and permeability. Glassy poly(ethersulfone) (PES) and rubbery poly(ethylene) glycol (PEG) are polymers that are known to have a high affinity towards CO2. In this paper, PEG and PES are reviewed as potential polymer blend that can yield a final membrane with high CO2 permeance and CO2/nitrogen (N2) selectivity. Gas separation properties can be enhanced by using different solvents in the phase-inversion process. N-Methyl-2-Pyrrolidone (NMP) and Dimethylformamide (DMF) are common industrial solvents used for membrane fabrication. Both NMP and DMF are reviewed as prospective solvent blend that can improve the morphology and separation properties of PES/PEG blend membranes due to their effects on the membrane structure which increases permeation as well as selectivity. Thus, a PES/PEG blend polymeric membrane fabricated using NMP and DMF solvents is believed to be a major prospect for CO2/N2 gas separation.


2013 ◽  
Vol 448-453 ◽  
pp. 765-770 ◽  
Author(s):  
Li Zhe Liang ◽  
Quan Gan ◽  
Paul Nancarrow

In recent years, the utilisation of ionic liquids supported on porous polymer membranes has been demonstrated to enhance gas separation performance by improving both permeability and selectivity for several industrially-relevant gas mixtures. However, the use of such supported ionic liquid membranes (SILMs) is normally not feasible at elevated process temperatures due to the resulting decrease in ionic liquid viscosity, which can lead to increased loss of ionic liquid from the membrane support during operation. In addition, many of the polymer membranes typically used in SILMs exhibit relatively poor mechanical and thermal stabilities at high temperatures. To overcome these problems associated with SILMs, thermally-stable composite ionic liquid and polymer membranes (CILPMs) have been fabricated in this study, thus exploiting the beneficial properties of ionic liquids for gas separation at elevated temperatures. Poly (pyromellitimide-co-4,4-oxydianiline) (PMDA-ODA PI) in combination with the ionic liquid, [C4mi [NTf2] were used to fabricate the CILPMs. A measurement rig was designed and built to determine permeabilities and selectivities of the CILPMs for H2, N2, CO, CO2 and CH4 over a range of pressures and temperatures. The fabricated CILPMs were shown to maintain excellent mechanical and thermal stability over a wide range of processing conditions. Temperature was shown to greatly affect both permeability and selectivity of the membranes, whilst pressure had less influence. The incorporation of [C4mi [NTf2] into the membranes was found to significantly increase CO2 permeation and, therefore, it is anticipated that these CILPMs hold significant potential for CO2 separation applications.


Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4181
Author(s):  
Md. Mushfequr Rahman

The energy-efficient separation of hydrocarbons is critically important for petrochemical industries. As polymeric membranes are ideal candidates for such separation, it is essential to explore the fundamental relationships between the hydrocarbon permeation mechanism and the physical properties of the polymers. In this study, the permeation mechanisms of methane, ethane, ethene, propane, propene and n-butane through three commercial multiblock copolymers PEBAX 2533, PolyActive1500PEGT77PBT23 and PolyActive4000PEGT77PBT23 are thoroughly investigated at 33 °C. This study aims to investigate the influence of cohesive energy density and crystallites of the polyether block of multiblock copolymers on hydrocarbon separation. The hydrocarbon separation behavior of the polymers is explained based on the solution–diffusion model, which is commonly accepted for gas permeation through nonporous polymeric membrane materials.


2017 ◽  
Vol 41 (5) ◽  
pp. 2090-2097 ◽  
Author(s):  
Dongshun Deng ◽  
Yaotai Jiang ◽  
Xiaobang Liu

A series of furoate-based ionic liquids with good absorption and separation performance for SO2 were reported.


Separations ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 29
Author(s):  
Cynthia A. Corley ◽  
Scott T. Iacono

There are many advantages to using ionic liquids as solvents or catalysts in chemical processes. Their non-volatile characteristic and high cost, however, can pose economic, environmental, and long-term health concerns. As such, the recovery and recycling of ionic liquids have become essential to mitigate their environmental impact and to reduce costs. Numerous recovery and recycling methods have been reported, including distillation, extraction, membrane separation (a.k.a. filtration), adsorption, crystallization, gravity, and electrochemical separation. Whereas most of these methods recover both cations and anions of the ionic liquid as ion pairs, recycling methods such as single-phase ion exchange or mixed-ion exchange/non-ionic adsorption methods recover only one of the ionic liquid ions, typically the cation. These methods are frequently used for the recycling of ionic liquids having simple anions such as chloride or acetate, but are seldom employed for ionic liquids consisting of larger and more complex anions due to the added time and reagent costs necessary for the regeneration of the original ionic liquid. Herein, a combined cation and anion exchange adsorption-desorption method is presented that can effectively separate 1,2-dimethyl-3-propylimidazolium bis(trifluoromethylsulfonimide) [DMPIm][NTf2] ionic liquid from neutral impurities. More importantly, the method is capable of recovery and recycling of the original ionic liquid. Concomitant desorption of both ionic liquid ions was achieved using 0.1 M NaCl: methanol (90:10 v/v) eluent followed by isolation using liquid–liquid extraction to afford high purity products and yields of approximately 60%.


RSC Advances ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. 6422-6431 ◽  
Author(s):  
Mengdie Li ◽  
Xiangping Zhang ◽  
Shaojuan Zeng ◽  
Lu bai ◽  
Hongshuai Gao ◽  
...  

A series of composite membranes with high gas transport properties enhanced by IL and ZIF-8 have been developed. The influence of ionic liquid and ZIF-8 addition on gas separation performance were systematically investigated.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Dzeti Farhah Mohshim ◽  
Hilmi bin Mukhtar ◽  
Zakaria Man ◽  
Rizwan Nasir

In the last few decades, membrane technology has been a great attention for gas separation technology especially for natural gas sweetening. The intrinsic character of membranes makes them fit for process escalation, and this versatility could be the significant factor to induce membrane technology in most gas separation areas. Membranes were synthesized with various materials which depended on the applications. The fabrication of polymeric membrane was one of the fastest growing fields of membrane technology. However, polymeric membranes could not meet the separation performances required especially in high operating pressure due to deficiencies problem. The chemistry and structure of support materials like inorganic membranes were also one of the focus areas when inorganic membranes showed some positive results towards gas separation. However, the materials are somewhat lacking to meet the separation performance requirement. Mixed matrix membrane (MMM) which is comprising polymeric and inorganic membranes presents an interesting approach for enhancing the separation performance. Nevertheless, MMM is yet to be commercialized as the material combinations are still in the research stage. This paper highlights the potential promising areas of research in gas separation by taking into account the material selections and the addition of a third component for conventional MMM.


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