Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part II: Gas Separation Properties toward Fluorinated Greenhouse Gases

Membrane technology can play a very influential role in the separation of the constituents of HFC refrigerant gas mixtures, which usually exhibit azeotropic or near-azeotropic behavior, with the goal of promoting the reuse of value-added compounds in the manufacture of new low-global warming potential (GWP) refrigerant mixtures that abide by the current F-gases regulations. In this context, the selective recovery of difluorometane (R32, GWP = 677) from the commercial blend R410A (GWP = 1924), an equimass mixture of R32 and pentafluoroethane (R125, GWP = 3170), is sought. To that end, this work explores for the first time the separation performance of novel mixed-matrix membranes (MMMs) functionalized with ioNanofluids (IoNFs) consisting in a stable suspension of exfoliated graphene nanoplatelets (xGnP) into a fluorinated ionic liquid (FIL), 1-ethyl-3-methylpyridinium perfluorobutanesulfonate ([C2C1py][C4F9SO3]). The results show that the presence of IoNF in the MMMs significantly enhances gas permeation, yet at the expense of slightly decreasing the selectivity of the base polymer. The best results were obtained with the MMM containing 40 wt% IoNF, which led to an improved permeability of the gas of interest (PR32 = 496 barrer) with respect to that of the neat polymer (PR32 = 279 barrer) with a mixed-gas separation factor of 3.0 at the highest feed R410A pressure tested. Overall, the newly fabricated IoNF-MMMs allowed the separation of the near-azeotropic R410A mixture to recover the low-GWP R32 gas, which is of great interest for the circular economy of the refrigeration sector.

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Preparation of Mixed Matrix Membranes Containing ZIF-8 and UiO-66 for Multicomponent Light Gas Separation

Crystals ◽

10.3390/cryst9010015 ◽

2018 ◽

Vol 9 (1) ◽

pp. 15 ◽

Cited By ~ 3

Author(s):

Eun Kim ◽

Hyun Kim ◽

Donghwi Kim ◽

Jinsoo Kim ◽

Pyung Lee

Keyword(s):

Gas Separation ◽

Gas Permeation ◽

Polymer Membrane ◽

Mixed Matrix Membranes ◽

Gas Mixture ◽

Separation Performance ◽

Mixed Matrix ◽

Neat Polymer ◽

H2 Permeability ◽

Matrix Membranes

Mixed matrix membranes (MMMs) containing zeolitic imidazolite framework-8 (ZIF-8) and UiO-66 as microporous fillers were prepared and evaluated their potential for the separation of a gas mixture produced by a methane reforming process. Hydrothermal synthesis was performed to prepare both the ZIF-8 and UiO-66 crystals, with crystal sizes ranging from 50 to 70 nm for ZIF-8 and from 200 to 300 nm for UiO-66. MMMs were prepared with 15% filler loading for both MMM (ZIF-8) and MMM (UiO-66). MMM (UiO-66) exhibited H2 permeability of 64.4 barrer and H2/CH4 selectivity of 153.3 for single gas permeation, which are more than twice the values that were exhibited by a neat polymer membrane. MMM (ZIF-8) also showed better separation properties than that of a neat polymer membrane with H2 permeability of 27.1 barrer and H2/CH4 selectivity of 123.2. When a gas mixture consisting of 78% Ar/18% H2/4% CH4 flowed into the membranes at 5 bar, the H2 purity increased to as high as 93%. However, no improvement in the mixture gas separation performance was achieved by the MMMs as compared to that of a neat polymer membrane.

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The CO2/CH4 Separation Potential of ZIF-8/Polysulfone Mixed Matrix Membranes at Elevated Particle Loading for Biogas Upgradation Process

International Journal of Renewable Energy Development ◽

10.14710/ijred.2021.33118 ◽

2020 ◽

Vol 10 (2) ◽

pp. 213-219

Author(s):

Putu Doddy Sutrisna ◽

Ronaldo Pangestu Hadi ◽

Jonathan Siswanto ◽

Giovanni J Prabowo

Keyword(s):

Renewable Energy ◽

Gas Separation ◽

Gas Permeability ◽

Gas Permeation ◽

Degree Of Crystallinity ◽

Polymeric Membrane ◽

Mixed Matrix Membranes ◽

Separation Performance ◽

Particle Loading ◽

Inorganic Particles

Biogas is a renewable energy that has been explored widely in Indonesia to substitute non-renewable energy. However, the presence of certain gas, such as carbon dioxide (CO2), can decrease the calorific value and generate greenhouse gas. Hence, the separation of CO2 from methane (CH4) occurs as a crucial step to improve the utilization of biogas. The separation of CH4/CO2 can be conducted using a polymeric membrane that needs no chemical, hence considered as an environmentally friendly technique. However, the utilization of polymeric membrane in gas separation processes is hampered by the trade-off between gas throughput and selectivity. To solve this problem, the incorporation of inorganic particles, such as Zeolitic Imidazolate Framework-8 (ZIF-8) particles, into the polymer matrix to improve the gas separation performance of the membrane has been conducted recently. In this research, ZIF-8 has been incorporated into Polysulfone matrix to form ZIF-8/Polysulfone-based membrane by simple blending and phase inversion techniques in flat sheet configuration. The pure gas permeation tests showed an increase in gas permeability (26 Barrer compared to 17 Barrer) after the inclusion of ZIF-8 particles with a slight decrease in CO2/CH4selectivity for particle loading more than 15wt. %. Therefore, the membrane with 15wt. % of particles showed the best performance in terms of gas selectivity. This result was due to the aggregation of ZIF-8 particles at particle loading higher than 15wt. %. Chemical analysis indicated an interaction between filler and polymer, and there were increases in the degree of crystallinity after the incorporation of ZIF-8.

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Effect of zeolite surface modification with ionic liquid [APTMS][Ac] on gas separation performance of mixed matrix membranes

Separation and Purification Technology ◽

10.1016/j.seppur.2018.05.040 ◽

2018 ◽

Vol 205 ◽

pp. 176-183 ◽

Cited By ~ 23

Author(s):

Ayesha Ilyas ◽

Nawshad Muhammad ◽

Mazhar Amjad Gilani ◽

Ivo F.J. Vankelecom ◽

Asim Laeeq Khan

Keyword(s):

Ionic Liquid ◽

Surface Modification ◽

Gas Separation ◽

Mixed Matrix Membranes ◽

Separation Performance ◽

Mixed Matrix ◽

Zeolite Surface ◽

Gas Separation Performance ◽

Matrix Membranes

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A Novel Composite Material UiO-66@HNT/Pebax Mixed Matrix Membranes for Enhanced CO2/N2 Separation

Membranes ◽

10.3390/membranes11090693 ◽

2021 ◽

Vol 11 (9) ◽

pp. 693

Author(s):

Fei Guo ◽

Bingzhang Li ◽

Rui Ding ◽

Dongsheng Li ◽

Xiaobin Jiang ◽

...

Keyword(s):

Composite Material ◽

Gas Separation ◽

Halloysite Nanotubes ◽

Gas Permeation ◽

Mixed Matrix Membranes ◽

Mixed Matrix Membrane ◽

Separation Performance ◽

Mixed Matrix ◽

Transport Pathways ◽

Gas Separation Performance

Mixing a polymer matrix and nanofiller to prepare a mixed matrix membrane (MMM) is an effective method for enhancing gas separation performance. In this work, a unique UiO-66-decorated halloysite nanotubes composite material (UiO-66@HNT) was successfully synthesized via a solvothermal method and dispersed into the Pebax-1657 matrix to prepare MMMs for CO2/N2 separation. A remarkable characteristic of this MMM was that the HNT lumen provided the highway for CO2 diffusion due to the unique affinity of UiO-66 for CO2. Simultaneously, the close connection of the UiO-66 layer on the external surface of HNTs created relatively continuous pathways for gas permeation. A suite of microscopy, diffraction, and thermal techniques was used to characterize the morphology and structure of UiO-66@HNT and the membranes. As expected, the embedding UiO-66@HNT composite materials significantly improved the separation performances of the membranes. Impressively, the as-obtained membrane acquired a high CO2 permeability of 119.08 Barrer and CO2/N2 selectivity of 76.26. Additionally, the presence of UiO-66@HNT conferred good long-term stability and excellent interfacial compatibility on the MMMs. The results demonstrated that the composite filler with fast transport pathways designed in this study was an effective strategy to enhance gas separation performance of MMMs, verifying its application potential in the gas purification industry.

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Pentiptycene-based ladder polymers with configurational free volume for enhanced gas separation performance and physical aging resistance

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2022204118 ◽

2021 ◽

Vol 118 (37) ◽

pp. e2022204118

Author(s):

Tanner J. Corrado ◽

Zihan Huang ◽

Dezhao Huang ◽

Noah Wamble ◽

Tengfei Luo ◽

...

Keyword(s):

Free Volume ◽

Gas Separation ◽

Physical Aging ◽

Gas Permeation ◽

Separation Performance ◽

Structure Property ◽

Mixed Gas ◽

Initial Separation ◽

Primary Advantage ◽

Polymers Of Intrinsic Microporosity

Polymers of intrinsic microporosity (PIMs) have shown promise in pushing the limits of gas separation membranes, recently redefining upper bounds for a variety of gas pair separations. However, many of these membranes still suffer from reductions in permeability over time, removing the primary advantage of this class of polymer. In this work, a series of pentiptycene-based PIMs incorporated into copolymers with PIM-1 are examined to identify fundamental structure–property relationships between the configuration of the pentiptycene backbone and its accompanying linear or branched substituent group. The incorporation of pentiptycene provides a route to instill a more permanent, configuration-based free volume, resistant to physical aging via traditional collapse of conformation-based free volume. PPIM-ip-C and PPIM-np-S, copolymers with C- and S-shape backbones and branched isopropoxy and linear n-propoxy substituent groups, respectively, each exhibited initial separation performance enhancements relative to PIM-1. Additionally, aging-enhanced gas permeabilities were observed, a stark departure from the typical permeability losses pure PIM-1 experiences with aging. Mixed-gas separation data showed enhanced CO2/CH4 selectivity relative to the pure-gas permeation results, with only ∼20% decreases in selectivity when moving from a CO2 partial pressure of ∼2.4 to ∼7.1 atm (atmospheric pressure) when utilizing a mixed-gas CO2/CH4 feed stream. These results highlight the potential of pentiptycene’s intrinsic, configurational free volume for simultaneously delivering size-sieving above the 2008 upper bound, along with exceptional resistance to physical aging that often plagues high free volume PIMs.

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Investigation of the silica pore size effect on the performance of polysulfone (PSf) mixed matrix membranes (MMMs) for gas separation

Journal of Polymer Engineering ◽

10.1515/polyeng-2021-0055 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Gholamhossein Vatankhah ◽

Babak Aminshahidy

Keyword(s):

Mesoporous Silica ◽

Pore Size ◽

Gas Separation ◽

Gas Permeation ◽

Mixed Matrix Membranes ◽

Separation Performance ◽

Mixed Matrix ◽

Small Pore ◽

Mcm 41 ◽

Matrix Membranes

Abstract MCM-41 and SBA-15 mesoporous silica materials with different pore sizes (3.08 nm for small pore size MCM-41 (P 1), 5.89 nm for medium pore size SBA-15 (P 2), and 7.81 nm for large pore size SBA-15 (P 3)) were synthesized by the hydrothermal method and then functionalized with 3-aminopropyltrietoxysilane by postsynthesis treatments. Next, polysulfone-mesoporous silica mixed matrix membranes (MMMs) were prepared by the solution casting method. The obtained materials and MMMs were characterized by various techniques including X-ray diffraction, scanning electron microscopy, and N2 adsorption-desorption, and Brunauer-Emmett-Teller method to examine the crystallinity, morphology, and particle size, pore volume, specific surface area, and pore size distribution, respectively. Finally, the gas permeation rates of prepared MMMs were measured in 8 bar and 25 °C and the effect of pore size of modified and unmodified mesoporous silica on the gas separation performance of these MMMs were investigated. The experimental results indicate that the carbon dioxide (CO2) and methane (CH4) permeability and CO2/CH4 selectivity were increased with an enhancement in the particle pore size.

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A Review on Ionic Liquid Gas Separation Membranes

Membranes ◽

10.3390/membranes11020097 ◽

2021 ◽

Vol 11 (2) ◽

pp. 97

Author(s):

Karel Friess ◽

Pavel Izák ◽

Magda Kárászová ◽

Mariia Pasichnyk ◽

Marek Lanč ◽

...

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Gas Separation ◽

Carbon Capture ◽

Reaction Medium ◽

Mixed Matrix Membranes ◽

Liquid Membranes ◽

Mixed Gas ◽

Separation Processes ◽

Ion Gels

Ionic liquids have attracted the attention of the industry and research community as versatile solvents with unique properties, such as ionic conductivity, low volatility, high solubility of gases and vapors, thermal stability, and the possibility to combine anions and cations to yield an almost endless list of different structures. These features open perspectives for numerous applications, such as the reaction medium for chemical synthesis, electrolytes for batteries, solvent for gas sorption processes, and also membranes for gas separation. In the search for better-performing membrane materials and membranes for gas and vapor separation, ionic liquids have been investigated extensively in the last decade and a half. This review gives a complete overview of the main developments in the field of ionic liquid membranes since their first introduction. It covers all different materials, membrane types, their preparation, pure and mixed gas transport properties, and examples of potential gas separation applications. Special systems will also be discussed, including facilitated transport membranes and mixed matrix membranes. The main strengths and weaknesses of the different membrane types will be discussed, subdividing them into supported ionic liquid membranes (SILMs), poly(ionic liquids) or polymerized ionic liquids (PILs), polymer/ionic liquid blends (physically or chemically cross-linked ‘ion-gels’), and PIL/IL blends. Since membrane processes are advancing as an energy-efficient alternative to traditional separation processes, having shown promising results for complex new separation challenges like carbon capture as well, they may be the key to developing a more sustainable future society. In this light, this review presents the state-of-the-art of ionic liquid membranes, to analyze their potential in the gas separation processes of the future.

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Improved CO2/CH4 Separation Properties of Cellulose Triacetate Mixed–Matrix Membranes with CeO2@GO Hybrid Fillers

Membranes ◽

10.3390/membranes11100777 ◽

2021 ◽

Vol 11 (10) ◽

pp. 777

Author(s):

Chhabilal Regmi ◽

Saeed Ashtiani ◽

Zdeněk Sofer ◽

Karel Friess

Keyword(s):

Gas Separation ◽

Chemical Properties ◽

Gas Permeation ◽

Mixed Matrix Membranes ◽

Inorganic Filler ◽

Separation Performance ◽

Mixed Matrix ◽

Hybrid Filler ◽

Hybrid Fillers ◽

Matrix Membranes

The study of the effects associated with the compatibility of the components of the hybrid filler with polymer matrix, which ultimately decide on achieving mixed matrix membranes (MMMs) with better gas separation properties, is essential. Herein, a facile solution casting process of simple incorporating CeO2@GO hybrid inorganic filler material is implemented. Significant improvements in material and physico-chemical properties of the synthesized membranes were observed by SEM, XRD, TGA, and stress-strain measurements. Usage of graphene oxide (GO) with polar groups on the surface enabled forming bonds with ceria (CeO2) nanoparticles and CTA polymer and provided the homogeneous dispersion of the nanofillers in the hybrid MMMs. Moreover, increasing GO loading concentration enhanced both gas permeation in MMMs and CO2 gas uptakes. The best performance was achieved by the membrane containing 7 wt.% of GO with CO2 permeability of 10.14 Barrer and CO2/CH4 selectivity 50.7. This increase in selectivity is almost fifteen folds higher than the CTA-CeO2 membrane sample, suggesting the detrimental effect of GO for enhancing the selectivity property of the MMMs. Hence, a favorable synergistic effect of CeO2@GO hybrid fillers on gas separation performance is observed, propounding the efficient and feasible strategy of using hybrid fillers in the membrane for the potential biogas upgrading process.

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CARBON DIOXIDE/METHANE SEPARATION PERFORMANCE BY MIXED MATRIX MEMBRANE FROM POLYSULFONE/ HALLOYSITE NANOTUBES

Jurnal Teknologi ◽

10.11113/jt.v82.14309 ◽

2020 ◽

Vol 82 (3) ◽

Author(s):

Noor Maizura Ismail ◽

Nur Afaliza Yusaini ◽

Jannah Jafa ◽

S. M. Anisuzzaman ◽

Chiam Chel Ken ◽

...

Keyword(s):

Gas Separation ◽

Halloysite Nanotubes ◽

Skin Layer ◽

Gas Permeation ◽

Mixed Matrix Membranes ◽

Inorganic Filler ◽

Mixed Matrix Membrane ◽

Separation Performance ◽

Mixed Matrix ◽

Morphological Differences

Gas separation by using membrane-based technology is one of the rising technologies used in the industry. It has many advantages such as low in cost and energy consumption. However, this technology is limited because of the "trade-off" exists between permeability and selectivity of the membrane. Thus, in this study, an inorganic filler, halloysite nanotube is modified with 3-aminopropyl(triethoxysilane) and then incorporated into the polysulfone polymer and the performance of the mixed matrix membranes (MMMs) is investigated. MMMs were analyzed by using SEM, FTIR, tensile and gas permeation tests which studied the morphological differences, mechanical strength, and membrane permeability and selectivity towards CO2 and CH4 respectively. The performance of the MMMs was compared with neat membrane and MMMs with unmodified HNTs. SEM results show an increase of 111% on the thickness of the dense skin layer of MMMs with APTES-modified HNTs compared to the neat membrane and the MMMs with unmodified HNTs. Elongation at break for MMMs with 3-APTES-modified HNTs also increased to 24.22%. The gas separation performance of the MMMs with 3-APTES modified HNTs shows an overall increase of 25.37% in the membrane selectivity compared to MMMs with unmodified HNTs while when coating is done, the selectivity of the MMMs with 3-APTES modified HNTs shows an increase from 0.845 to 10.158 for a pressure of 2 bar showing that coating helps in increasing the selectivity of the membrane.

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