New advances in polymeric membranes for CO separation · 2016-06-15 · New advances in polymeric...

New advances in polymeric membranes for CO2 separation

Abtin Ebadi Amooghin1,*, Hamidreza Sanaeepur1, Mona Zamani Pedram2, Mohammadreza Omidkhah3 and Ali Kargari4

1 Department of Chemical Engineering, Faculty of Engineering, Arak University, Arak 38156-8-8349, Iran 2 Department of Energy System Engineering, Faculty of Mechanical Engineering, K. N. Toosi University of Technology,

No. 15, Pardis St., Molasadra Ave., Vanak Sq., Tehran 3 Faculty of Chemical Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran, Iran 4 Department of Chemical Engineering, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran, Iran * Corresponding author: email: [email protected], [email protected]

Energy has been proposed as a feed of the long-term development. Fossil fuel burning serves the main part of energy needs. The projections of world energy consumption by all the energy sources up to the mid-21stcentury introduce natural gas stays on ahead of the others. It involves with the simultaneous challenges of CO2 separation from natural/bio gas (acid gas removal) as well as subsequent capture of CO2 emitted from power plants (in order to mitigating the global warming accompanied by CO2 emission). Membrane gas separation has crucial advantages among all other CO2 separation technologies such as absorption, adsorption, and cryogenic distillation. One of the main purposes of research in membrane gas separation is fabrication of membranes with superior permeability and selectivity. Although polymeric membranes possess many advantages such as the ability for easy fabrication of large membrane areas at low cost, they suffer from problems associated with the trade-off relationship between permeability and selectivity. Therefore, they traditionally undergo an upper bound limitation. Although there are many opportunities for polymeric-based membrane for gas separation applications, but most of the existing membrane materials cannot economically utilize in these opportunities. Therefore, even today, many progresses are made in alternative emerging materials in order to develop the CO2 separation performances. There are various methods have been examined to improve current levels of membrane performance such asgrafting, blending, crosslinking, ion-exchange treatment, mixing with suitable dense/molecular sieve fillers and etc. This chapter is especially devoted to explain challenging issues affect the CO2 separation properties of conventional polymeric membranes. Moreover, advanced classes of highly CO2 separation performance polymeric membranes are summarized.

Keywords: advanced polymers; membranes; CO2 capture; natural gas; greenhouse gases.

1. Introduction

1.1 Membrane Technology

Membrane is generally defined as a selective barrier between two phases. In other words, membrane is a thin solid and/or fluid film which is mainly characterized by permselectivity properties of penetrants. It must be noted that the pentrant flux is affected by the physical structure of the membrane, while the transport driving force through the membrane is the chemical potential gradient. Hence the selectivity is considered as a discrepancy in flux between penetrants [1]. The membrane gas separation industry has grown dramatically over the past four decades and this growth has been owed to the fast development of more efficient membranes with higher permselctivities. As it is known, the first membrane gas separation industrial systems were experienced in 1979−1980 for separation of H2 from the N2, argon, and CH4. The economic benefits of the hydrogen recovery led to very rapid installation of several systems around the world [2]. Afterwards, membrane gas separation was used in other applications such as separation of CO2 from natural gas, N2 from air and H2 from different refinery and petrochemical process streams [3-5]. This is due to noteworthy advantages of membranes such as low cost, high efficiency, simple operation, modularity and easy to scale up and the outstanding one; continuous steady-state conditions which gas separation devices can operate under them. Up to now, despite the fact that thousands of new materials used in membrane gas separation technology, but unfortunately only a limited number of them are employed in the industry [2]. Membrane gas separation are used in many applications such as the separation of N2 or O2 from air, separation of H2 from N2 and CH4, H2 recovery from product streams of ammonia plants and also in oil refinery processes, separation of CH4 from biogas, air enrichment by O2 for medical or metallurgical applications, water vapor removal from natural gas and other mixtures, CO2 and H2S removal from natural gas, volatile organic liquids (VOLs) removal from exhaust streams [1]. Membrane materials for gas separation must possess the intrinsic-tailoring properties such as: 1) stability for use in long-term purposes 2) acceptable permselectivity 3) well membrane structure and thickness 4) suitable design of modular system [3].

Polymer science: research advances, practical applications and educational aspects (A. Méndez-Vilas; A. Solano, Eds.) _______________________________________________________________________________________________

354

1.2 Membrane CO2 separation

Nowadays, the amount of greenhouse gases (GHGs) in the atmosphere has increased significantly [6]. The severe sideffects of carbon dioxide accumulation in the environment as a main constituent of greenhouse gases, causes too much attention to the variety of separation methods of CO2 from the flue gases. As previously mentioned, polymeric membrane gas separation is a promising technology, if the prepared membranes have good intrinsic properties such as high permeability, moderate selectivity, longterm reliable working at specific operating conditions in post-combustion (flue gas mixture at 323 K and atmospheric pressure with at least 10-15% CO2 content) [7-17]. In general, polymeric membranes with pemeance>1000 GPU and selectivity>30 are the good candidates for CO2 separation from the flue gases [18, 19]. On the other hand, the separation of CO2 and CH4 is also a well-known industrial process. To demonstrate the importance of this issue, it is sufficient to point out that the need to considerable treatment of approximately 20% of the US annually natural gas, which is about 20 trillion standard cubic feet, is clearly showed the volume of financial and operational separation process [20]. More importantly, at higher concentrations of CO2 (more than 2%) in pipeline, many disadvantages are appeared such as pipeline corrosion as well as decreasing the heat value of natural gas [20-22]. Comparing with conventional methods, membrane gas separation reveals certain advantages including high efficiency, low cost and environmental impact [23-26]. However, the main problems of current polymeric membranes are the restriction of permselectivity (they only can process low volumes of gas less than 30 million of standard cubic feet per day), and unsatisfactory thermal-chemical stability and surrender to plasticization [20, 23]. Thus, any little progress in the production of gas separation membranes, includes significant financial saving and causes the membranes to become more prominent position in industrual gas separation [27].

2. Polymeric membranes

2.1 Conventional polymers

Up to now many polymers have been used in the fabrication of gas separation membranes including: polyacetylenes, polyaniline, poly(arylene ether)s, polyarylates, polycarbonates, polyetherimides, poly(ethylene oxide), polyimides, poly(phenylene oxide)s, poly(pyrrolone)s and polysulfones. There are some challenges issues dealing with the use of these materials that has been attracted many research interests. Thermal and pressure conditioning, phisycal and chemical aging, plasticization, permeation hysteresis, casting solvent, and impurities or presence of trace contaminants are some of the problems in the field [28,29].

2.1.1 Conditioning

“Conditioning” alters the gas permeabilities of polymers, especially the glassy ones. Thermally treated or annealed membranes provides different permeabilities as compared with similar untreated ones and even by those of treated at different conditions. For example, the value of CO2 permeabiliy in celluse acetate (CA, M.W.=30,000) membrane annealed at 150 °C for 48 h in a vacuum oven was determined as 2.20 Barrer whereas it was varied to 3.34 Barrer for the simple dried membrane at 40 °C for 48 h in a vacuum oven [30]. The value for the CA with M.W.=50,000, annealed at 180 °C for 24 h in a vacuum oven, was reported as 7.5 Barrer [31].

2.1.2 Aging and anti-aging

The excess free volume of glassy polymers can experience changes owing to processing conditions, thermal history, and exposing to sorbing materials. As the polymer chains in the amorphous regions of a glassy polymer leave their equilibrated configurations, this unrelaxed or excess free volume entrapped between polymer chains releases outside the polymer matrix through a diffusion-like phenomenon. This is known as “physical aging” that induces the time-dependent membrane transport properties [32]. This is particularly pronounced in thin films. A method of tracking physical aging of thin glassy polymer films accompanying with gas separation has proposed by Huang and Paul [33]. Due to physical aging, the packing density increases over time and the permeability drops dramatically. This usually accompanied by an increase in selectivity, which is seen as a reduction in membrane flux over time [34]. Recently, the role of membrane thickness on physical aging was also recognized, particularly for the membrane (selective) layer thickness less than 1 micron. As the practical gas separation membranes often are < 0.1 mm in thickness, the effect of thickness on aging has been a relevant field of study [35]. While both the physical and chemical aging are time and temperature dependent, the chemical aging results in an alteration of the chemistry of the polymeric membrane and usually leads to membrane degradation with a simultaneous decline of the properties (e.g. coloration, embrittlement). On the other hand, physical aging alters the local packing of the chains but results in no changes in the polymer structure. Therefore, only the dimensions and physical properties of


355

the polymer (such as brittleness, tensile strength, and the glass transition temperature, Tg) alters. Thus the main difference between the two effects is that physical aging is a reversible process, whereas chemical aging is not [36]. There are two “anti-aging” approaches including (1) freezing the fractional free volume state in place via the inorganic/organic porous/nonporous fillers, polymer blending, to increase open transport pathways, and (2) employing cross-linking, co-polymerization and surface plasma treatment for rigidifying the initial polymer structure in place. Additives can not sufficiently stabilize the FFV to stop aging, whereas cross-linking can successfully stop aging but at the expense of major loss in permeability [37]. The inability to stop aging in conventional glassy polymers provided a research motivation for new rigid, porous, super glassy materials like polymers with intrinsic microporosity (PIMs). PIMs are constructed by rigid components which are especially internally flexible, and have points of contortion [37]. A new approach (3) was presend from combing two above methods to solve the problem of polymer aging by the addition of a very specific microporous microparticle, “porous aromatic framework” (PAF, Fig. 1A), into the super glassy polymers to form an interwoven nanocomposite. PAF can freeze the polymer structure and hence stopping the aging process (Fig. 1B) whilst increasing the gas permeability and selectivity. The high surface areas in PAFs (≥ 5000 m2g-1) accompanied by functionalization can lead to ultrahigh affinities for adsorption of CO2 and other gases. For example the addition of PAF-1 with the regular nanopores of around 1.2 nm diameter to super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP), poly(4-methyl-2-pentyne) (PMP), and polymers with intrinsic microporosity (PIM-1) largely stops aging; whilst it enhanced CO2 permeability for one year and improving CO2/N2 selectivity [37].

2.1.3 Casting solvent

“Casting solvent” can affect the crystalline/amorphous structure of polymeric membrane and hence alters the permeability. Additionally, the differences in the molecular sizes of the solvents can introduce different free volumes in the membrane fabrication process and, in turn, different solubility coefficient values [38,39]. In addition, casting solvent play a key role in the morphology of polymeric blend membranes. Zamiri et al. [40] showed the completely compact structure of ethylene vinyl acetate (EVA)/liquid poly (ethylene glycol) (PEG) blend membranes changes by the evaporation of solvent from the blends; whilst some cavities appear in the membrane matrices. Chloroform acts as solvent and PEG acts as non-solvent for EVA and EVA is dissolved in the mixture of chloroform and PEG. By gradual evaporation of chloroform from the casted solution, there will be a higher composition of EVA and non-solvent PEG in the solution, therefore, the polymer precipitates and the cavities appear. They also showd for the samples with 20 wt.% of PEG, the cavities are enlarged and interconnected which makes a significant drop in the (CO2/N2) gas selectivity.

Fig. 1 A) Synthesis of PAF-1 particles. B) Super glassy polymer/PAF-1 intermixing. Typically a) PTMSP, PMP, and PIM-1 densify to give a non-permeable conformation, b) but with the addition of PAF-1, c) the original permeable structure is maintained [37].

2.1.4 Impurities

The effect of “impurities or presence of trace contaminants” on the CO2 permeability of membranes can be proposed as an important concerning issue. Impregnating the gas flow with the pump compressor oils, existence of the water vapor in the feed, and associated aromatic/heavy hydrocarbons commonly exist in the field condition influnce the performance of a number of gas separation membranes [41,42].


356

2.1.5 Plasticization

An increase in the mass uptake (adsorption) of CO2, H2O, H2S, and higher hydrocarbones – known as condensable penetrants – inside the conventional polymeric membranes leads to swelling of the polymer, and in turn, increasing the polymer free volume (dilation) and its segmental mobility. This increases gas diffusivity or usually decreases gas diffusivity selectivity, a phenomenon refered to as “penetrant-induced plasticization” or briefly “plasticization” [43]. Plasticization often results in higher (CO2) gas flux but lower (CO2/CH4 and CO2/N2) mixed gas selectivities of traditional membrane materials (like CA, polyimides, polysulfones), particularly at high pressures. For glassy polymeric membranes that plasticize, gas permeability usually decreases with increasing feed pressure until plasticization occurs and then it begins to increase with increasing pressure. As the case of CO2–induced plasticization in glassy polymers, typical “plasticization pressures” are 10-35 bar for polymers relevant to gas separations, and the related CO2 concentrations in such polymers are ranging from 30 to 45 cm3(STP)/cm3 polymer, at the plasticization pressure [34]. These values – are not the same as the equilibrium values for low upstream pressures – increases also in time. This time-dependent relaxation process of the polymer is claimed to has its origin in the nonequilibrium glassy state of the polymer. It is stated that the sorbed penetrant swells and therefore loosens the polymer matrix, which is resulted in the suppression of glass transition temperature, Tg [44]. Plasticization of glassy polymers can be suppressed by three alternative methods: (1) blending with a less plasticizable polymer, (2) chemical cross-linking, and (3) thermal treatment [45,46]. Thermal treating has been previously discussed and therefore the two others will be considered below. In addition to reduce the plasticization, blending often improves the mechanical, thermal and separation properties of the polymeric membranes [47-49]. Facilitated transport of a specific gas can be achieved by tuning the blend compositions and the subsequent morphologies which are formed [50,51]. In many cases, a phase-separated blend is required for better transport of species [50]. Miscible/homogeneous blends are more suitable for increasing the gas selectivity whilst the permeability increases more with the immiscible blends. A polymer free volume expansion occurs during the mixing process of immiscible blends results in increased gas permeation rates. On the other hand, a homogeneous, miscible polymer blend shows a significant negative volume change in mixing that results in a significant decrease in gas permeation rates and consequently an increase in gas selectivities [52]. In some cases, a combination of cross-linking and blending has been considered to achieve the better properties. For example, Mondal and Mandal [53] has synthesized the CO2-selective cross-linked thin-film composite poly(vinyl alcohol) (PVA)/polyvinylpyrrolidone (PVP) blend membranes doped with suitable amine carriers. Formaldehyde was used as cross-linking agent. They obtained a very high CO2/N2 selectivity of 370 and a CO2 permeability of 1396 Barrer at 2.8 atm and 100 °C. A new approach has been developed as “hybrid ternary blends” which means compatibilization of the blend constituents by the addition of targeted fillers. The presence of suitable fillers, in addition to improve the mechanical properties, can also induces a considerably decrease in plasticization of the blends [54,55]. Qiu et al. [56] showed that cross-linking at elevated temperatures (∼15 °C above Tg) for polyimides can stabilize membranes against swelling and plasticization in aggressive feed streams. However, such a high temperature might result in collapse of substructure and transition layers in the asymmetric structure of the membranes. Therefore, they considered thermal cross-linking of the polyimides at temperatures much below the Tg. The “sub-Tg cross-linking” results indicated that the selectivity of the crosslinked membranes can be maintained even under very aggressive CO2 operating conditions that are not possible without cross-linking. Moreover, the plasticization pressures indicated a significant shift to higher pressures [56]. Combination of grafting and cross-linking (GC) were also presented as an advanced technique to inhibition of plasticization. Through this approach, Achoundong et al. [57] could modify the cellulose acetate (CA) membranes via grafting of vinyltrimethoxysilane (VTMS) to –OH groups, with subsequent condensation of hydrolyzed methoxy groups on the silane to form a polymer crosslinked network. Since the modification includes a combination of grafting and cross-linking with VTMS, it refered as “GCV” modification. A schematic of the modification reaction was presented at Fig. 2. The modified membranes maintains similar CO2/CH4 selectivities compared to the unmodified ones; however a pure CO2 permeability of 139 Barrer was obtained that was more than an order of magnitude higher than that of the neat CA polymer.

2.1.6 Anti-plasticization

“Anti-plasticization” is another phenomenon that disturbs separation performance of polymeric membranes. With an opposite behavior of plasticization, it influences polymeric membranes at low concentration of a specific penetrant; this penetrant molecule, instead of increasing the segmental motions of polymer chains as did for the plasticization, induces an evidence delay in chain fluctuations and hence decreases the diffusion of all other penetrants in the membrane [33]. Therefore, anti-plasticization through a mechanical mechanism, i.e. a reduction of segmental mobility or increased stiffness, decreases the gas permeabilities whilst the related selectivities are varied in a different manner [58]. Maeda and Paul [59,60] have investigated the antiplasticization effects of tricresyl phosphate (TCP), N-phenyl-2- napthylamine (PNA) and 4,4ʹ- dichlorodiphenylsulfone (DDS) on the polysulfone (PSf) and poly(phenylene oxide) (PPO)


357

membranes. The addition of these low molecular weight diluents or plasticizers to these polymers accompanied by significant reductions in sorption level and the permeabilities for gases like He, CO2, and CH4. In the low antiplasticizer concentrations the selectivities increased while exceeding from a determined concentration leads to decrease in selectivities due to the substitution of antiplasticization with anti-plasticization effect. Accordingly, they did not observed an improved trade-off between selectivity and permeability (Fig. 3).

Fig. 2 GCV-modification reaction mechanism [57].

2.1.7 Hysteresis

Another challenging issue in the most conventional glassy polymers is a “hysteresis” shown in permeation, sorption, and dilation isotherms of CO2. These properties measured during feed pressurizing are substantially lower than those measured while feed depressurizing. This hysteresis in the properties can be considered as a result of a slow polymer chain reorganizations in the time-scale of the CO2 pressure increments. This hysteresis can be significantly affected the membrane performance by an operational upset (e.g., feed pretreatment failure and subsequent exposure to heavy hydrocarbons), even if it is only for a short duration [61,62].

2.2 Inorganic polymers

In spite of the widespread implementation of organic polymers in membrane fabrication, why scientists are interestingly interested in the synthesis of membranes form inorganic polymers? Two aspects can be discussed here. On one hand, most of the existing organic polymers looses their – stablished as an “idead membrane material” – properties over the long period of time or heat, degrades exposed to ultraviolet or gamma radiation, or swells or dissolves in organic solvents, oils, or hydraulic fluids. On the other hand, a different chemistry of inorganic elements compared to the carbon atoms, in the backbone of a polymer, can alter the properties. In comparison with the carbon bonds, a bond formed between the inorganic elements has a longer, stronger, and more resistant to free radical cleavage reactions. Inorganic elements can also have different valencies than carbon, and hence, the number of side groups attached to a skeletal atom may be different from the situation in an organic polymer. Additionally, the use of non-carbon elements in the polymer backbone provides opportunities for tailoring the chemistry in ways that are not possible in totally organic macromolecules [63].


358

Fig. 3 Trade-off between selectivity and permeability for the CO2/CH4 gas pair [59,60]. Up to now, silicon, germanium, tin, phosphorus, and sulfur have been considered in the synthesis of inorganic polymers. However, the two elements of silicon and phosphorus has attracted almost all the attention. Silicon based polymers are categorized by two sets of polysiloxanes and polysilanes, wherein the phosphorus based ones only includes polyphosphazenes (Fig. 4) [63].

Polysilane Polysiloxane Polyphosphazene

Fig. 4 The chemical structures of commonly used inorganic polymers. Polydimethylsiloxane (PDMS) rubber, with the lowest Tg and the most flexibility among the others, is a well-known silicon based polymer for its high intermolecular free volume which has led to a high gas permeability [64]. Polyphosphazenes have been identified as outstanding CO2 selective membrane materials. These materials as other rubbery polymers exhibit high gas diffusion rates with low diffusivity selectivity [65]. Aryloxy-, and fluoroethoxy-substituted polyphosphazenes have received the most attention in CO2 separation membranes due to the high CO2 permeabilities [63].

3. Advanced polymers

Here, novel advanced polymers which should be interesting for membrane preparation is briefly explained. We explore very important applicable classes of highly CO2 separation performance polymeric materials such as polymers of intrinsic microporosity (PIM), thermally rearranged (TR) polymers, polyimides and polyurethanes.

3.1 Polymers of intrinsic microporosity (PIMs)

PIMs are new advanced materials which are recently widely used for the CO2 capture. PIMs due to their high free volume, offer remarkable permeability combined with good selectivity. However, physical ageing causes reduction of their performance over time [66-70]. PIMs are constructed based on rigid ladder backbone structures. In 2002, McKeown et al. [71,72] reported the pioneering work on new ladder polymers containing sites of contortion which this polymer has high surface area cross-linked polymer networks. Afterwards, Budd et al. [73,74] confirmed that rigid ladder polymers with high solubility and excellent mechanical properties, could be prepared for membrane fabrication. These kind of polymers which are prepared by polycondensation reaction of tetrahydroxy-monomers containing spiro- or contorted centres with tetrafluoromonomers, revealed exclusive properties such as: - They have no degrees of conformational freedom - They are adequately contorted to avoid effective packing of the macromolecules in the solid state - Having good mechanical strength through entanglement


359

- Lack of correlation between the microporosity of PIMs (intrinsic microporosity) and process/thermal treatment history as previous materials

- They have interconnected pores less than 2 nm in size, excellent solubility and are willingly processable, compared with other conventional molecular sieves [34,75-77].

The famous PIMs (PIM-1 and PIM-7) and Other PIMs (PIM-2 to PIM-6) are synthesized in the same way employing different aromatic tetrols and polyfluorine containing aromatic compounds. Despite PIM-1 and PIM-7 were exclusively reported to form films enough for membrane tests, two key factors are the main problems of film formation: low molecular weights and also low yields which cause negative effects on membrane mechanical properties. PIM-1 which is obtained by polycondensation reaction of commercial monomers 5,5,6,6-tetrahydroxy-3,3,3,3-tetramethylspiro-bisindane with tetrafluorophthalonitrile, is one of the primary class of PIMs designated for a fluorescent yellow high molecular weight polymer. PIM-1 is readily soluble in various kind of solvants and has excessive gas permeabilities with acceptable selectivity which can well compete Robeson upper bounds for several gas pairs, such as O2/N2, CO2/CH4 and CO2/N2 [66]. Moreover, PIM-1 has very high CO2 permeability and this is due to fact that the solubility mechanism is the dominated mechanism for CO2 permeation through the membrane compared with diffusion mechanism. The interesting point is that various kind of molecular units with different lengths between the spirocentres such as thianthrene [78], 9,10-dimethyl-9,10-dihydro-9,10-ethanoanthracene [79], ethanoanthracene [80] and PIM-7 containing pyrazine [81], could be incorporated in PIM membranes for adjusting the gas permeation properties. In addition,incorporation of dinaphthyl [82], spirofused fluorene-based monomers [83], and 1,2- or 1,4-di(3ʹ,4ʹ-dihydroxyphenyl) tetraphenylbenzene [84] with different angle of the spiro or twist centres are considerably changed the gas permeation properties. Furthermore, various pendant substituents on backbone such as carboxylic acid groups [85], sulfone-based groups [86], and trifluoromethyl groups [88], could also enhanced chain rigidity and efficiently tunes the cavity size and shape [87]. Du et al. [88] fabricated new class of PIMs by incorporating tetrazole (TZ) groups into the microprous polymeric framework and found that TZPIM has a promising combination of superior CO2/N2 permselectivity under mixed gas experiment. This may be due to the presence of the tetrazole groups which leads to considerable CO2 sorption compared to N2 and this causes the selective pore blocking by presorbed CO2 molecules that hinder access N2 molecules. The CO2/CH4 and CO2/N2 mixed gas selectivities in TZPIMs were not reduced under mixed gas conditions. At 10 atm, TZPIMs revealed a CO2/CH4 selectivity of about 17.5 in both pure and 50-50 mixed gas experiments. Moreover, they exhibited the CO2/N2 mixed gas selectivity of about 37.5 and claimed that this increase in selectivity was attributed to solubility properties [87]. Despite the excellent properties of these membranes, under mixed gas experiments, more efforts need to be made on effect of plasticization, physical aging at thicknesses of 1 micron or less, molecular weights, and mechanical behavior of PIMs [34]. The chemical structure of the PIM-1is depicted in Fig. 5.

Fig. 5 (a) Chemical structure of the PIM-1. (b) Molecular model of a fragment of PIM-1 [70].

3.2 Thermally rearranged (TR) polymers

Thermally rearranged (TR) were developed to achieve more uniform cavity sizes which make tailored free volume elements with well-connected morphology in amorphous polymers. These new family of polymeric membranes were prepared by a thermal post-membrane conversion process of functionalized polyimides [19]. Park et al. [89,90] considered the polybenzoxazole (PBO) and polybenzothiazole (PBT) dense membranes for polymer modifying reaction by thermal rearrangement of soluble aromatic polyimides including ortholinkage positioned functional –OH and –SH groups. The unexpected physical phenomena in TR polymers are of great importance in that the random chain conformations occurring in the condensed polymer phase lead to tuned microvoids, which contribute to performance enhancement in


360

selective molecular transport. The main advantage of TR polymers is good control of cavity size and distribution and thus average interchain spacing and free volume elements, by proper selection of template molecules and heat treatment protocols [89]. TR process increases the average size of free volume element and makes the size distribution of the elements more uniform and this confirmed by positron annihilation lifetime spectroscopy (PALS) and molecular modeling [90,91]. Although, increasing the free volume may lead to both an increase in diffusivity and solubility, but the contribution of diffusivity is much more than solubility. Hence, the TR polymer performance is strongly dependent on the structure property [89,92-97]. The need for high temperatures up to 400 ºC in TR process on imide-to-benzoxazole conversion, reduces the mechanical properties of the membrane [92,98,99]. Therfore, it is possible to decrease the TR process temperature by employing the flexible bisphenol A type dianhydride to reduce the Tg of the precursors [100]. TR polymers can be widely applied, if their weaknesses related to high conversion temperature and the effects of physical aging on TR polymer thin films, have been eliminated. TR polymers reveal outstanding CO2/CH4 separation performance, good resistance to CO2-induced plasticization and high chemical resistance. In other words, the thermal rearrangement concept offers practicable method for preparing high performance polymeric membranes suitable for gas separations especially for natural gas processing [101]. For instance, the TR-1 polymer which contains a fluorinated diamine and dianhydride, reveals a CO2 permeability and CO2/CH4 selectivity of about 2000 Barrer and 40, respectively. Moreover, it is not experienced the plasticization up to 15.2 bar. Fig. 6 illustrates the general scheme of thermal rearrangement (TR) of poly(hydroxyimide)s.

Fig. 6 General scheme of thermal rearrangement (TR) of poly(hydroxyimide)s [34].

3.3 Polyimides

Glassy polymers due to their excellent mechanical properties, tunable free cavities and intrinsic high selectivity were extensively employed for fabrication of MMMs [102-105]. Polyimides are among the most attractive types of glassy polymers for CO2 separation [106-108]. Polyimides are generally synthesized by step polymerization including a thermal or chemical imidization of a bis(carboxylic anhydride) and a diamine. Many factors directly affects the gas permeation properties in polyimide membranes such as bulky/polar groups incorporated into the polymer structures, spatial linkage configurations, type of bridging groups, meta-linkages, swivel linkages containing bulky groups, and polar and bulky pendant groups [109]. For instance, polyimides prepared by 4,40-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) with various bulky bridging groups such as diamines like 3,30- dimethylnaphthidine (DMN) [110,111] and 2,3,5,6-tetramethyl-1,4-phenyldiamine (4MPDA) [112,113], reveal high CO2/CH4 permselectivity. This is due to the presence of –C(CF3)2– linkages in their structure which leads to increase the chain stiffness and decrease the intra-segmental mobility. Hence, the degree of chain packing is limited and the FFV would increase. Here, the highest permselectivity has been reported for polyimides, which is defeated the Robeson upper bound, is related to the polyimides containing spiro-centres [114,115], bulky bis-phenylfluoreny [116] and three-dimensional rigid triptycene frameworks [117]. The results of polyimides containing various polar or bulky groups such as silica pendant groups, hydroxyl, carboxylic acid and sulfonic acids, exhibits high permeable membranes [118,119]. The presence of these groups led to increase in inter-chain spacing and reduce the packing efficiency of polymer chains. On the other hand, polyimide problems originate from chain flexibility and the non-equilibrium state of glassy polymers, are swelling and plasticization in the precence of CO2in mixed gases. In order to eliminate these undesirable issues, several methods are employed such as cross-linking of carboxyl-containing polyimides with aliphatic diamines (C2–C4) or propanediol or by a thermal decarboxylation cross-linking reaction [120]. Matrimid®5218 is a prominent aromatic polyimide, which originally developed for use in the microelectronics industry, but it has been also employed as a polymer matrix to fabricate membranes. Furthermore, Matrimid®5218 with pure CO2 permeability of 10 Barrer and a CO2/CH4 selectivity of 36, reveals the outstanding CO2/CH4 permselectivity among various commercially relevant polymers such as polysulfone, TB-bisA-polycarbonate and cellulose acetate [34,102,108].

3.4 Polyurethanes

Polyurethanes (PUs) are thermoplastic elastomers that consist of two segments at the micro phase level. The soft segment comprises diols which can derive from either polyesters or polyethers and form flexible chain structures resulted in excellent permeability. On the other hand, hard segment contains diisocyanate and chain extenders which makes the mechanical strength of polyurethanes [121]. Polyurethane membranes are suitable for separation of gas mixtures consist of both polar/non-polar components. Li et al. [122] studied the gas permeation properties of poly(urethane urea)s containing different polyethers such as poly(ethylene glycol) (PEG) 2000, poly(propylene glycol) (PPG) 2700, poly(tetramethylene ether glycol) (Terathane®) 2000, Terathane® 2900 and a mixture of PEG 2000 and


361

Terathane®2000. They found that the FFV and permeability increased, when the content and molecular weight of polyether increased in membrane structure. On the other hand, these membranes faced to lower selectivities. Simmon [123] reported the mixed gas separation properties of polyether-urethane or polyether-urea block copolymers based membranes. The results showed that the fabricated membranes revealed superior permselectivity. Poly(urethane urea) membrane has the gas solubilities in the order of H2S > CO2> CH4> O2> N2. This is due to the fact that H2S has dipolar and CO2 has quadrupolar properties. In fact, the gas permeability is strongly depends on the number of the urea linkages appear in the polymer structure. In other words, the polymer chain mobility and inter-chain distances are enhanced, as the urea linkages in PU structure are increased [121]. Table 1 reports data for selected high performance advanced polymeric membranes.

4. Future outlooks and conclusions

Developing the separation performance of polymeric membranes for CO2 separation industry is an extensive area of research, because membranes can compete with other separation technologies based on safety, environmental, economic and technological perspectives. Indeed, one the most important part of membrane gas separation processes is an appropriate selection of the materials. Thus, improving polymer membranes with higher permselectivities relieves concerns about the high cost of membrane technology. Therefore, current efforts should focus on elimination of these by introducing new polymer membranes which can have high CO2 permeability coupled with acceptable selectivity and good physical and chemical stability. Up to now many polymers have been employed in the fabrication of gas separation membranes including: polyacetylenes, polyaniline, poly(arylene ether)s, polyarylates, polycarbonates, polyetherimides, poly(ethylene oxide), polyimides, poly(phenylene oxide)s, poly(pyrrolone)s and polysulfones. There are some challenging issues dealing with the use of these materials that has been attracted many research interests. Some of the main problems in the field arethermal and pressure conditioning, phisycal and chemical aging, plasticization, permeation hysteresis, casting solvent, and impurities or presence of trace contaminants. This review is especially devoted to explain challenging issues affecting the CO2 separation properties of conventional polymeric membranes. Moreover, advanced classes of highly CO2 separation performance polymeric membrane are summarized. These membranes that exhibited higher potential for CO2 separation are mainly polymers of intrinsic microporosity (PIM), thermally rearranged polymers (TR polymers), polyimides and Polyurethanes. Therefore, gas separation industry is waiting for high-performance membranes to separate various CO2-contaning gas mixtures. Future direction of CO2 separation membranes should focus on improve these economically efficient polymers by better understanding the capability for industrial implementation.


362

Table 1 Gas permeation properties of advanced polymeric membranes.

Membrane T

(°C) p (bar)

PCO2 (Barrer)

PCH4 (Barrer)

PN2 (Barrer)

αCO2/CH4 αCO2/N2 Ref.

PIM-1(methanol treated) 25 1 5120 340 270 15.06 18.96 [70] PIM-1/grapheme (0.00096 wt.%) 25 1 12700 1450 870 8.76 15.60 [70] PIM-1/grapheme (0.0018 wt.%) 25 1 9840 800 570 12.30 17.26 [70] PIM-1/grapheme (0.0034 wt.%) 25 1 7830 550 410 14.24 19.10 [70] PIM-1/grapheme (0.0071 wt.%) 25 1 3410 160 170 21.31 20.06 [70] PIM-1 (methanol treated) 30 0.2-0.3 11200 1160 610 9.60 18.40 [124] PIM-1 30 0.2-0.3 2300 125 92 18.00 25.00 [125] PIM-1 30 0.2-0.3 1100 62 42 17.70 26.20 [77,125] PIM-7 30 0.2-0.3 1100 62.4 --- 17.7 --- [125] PIM-PI-1 30 0.2-0.3 1100 77 48 14.30 22.90 [126] PIM-PI-8 30 0.2-0.3 3700 260 161 14.20 23.00 [126] PIM1-CO15-75 30 0.2-0.3 2570 180 110 14.30 23.40 [127] PIMCO2-CO15-50 30 0.2-0.3 5300 430 260 12.30 20.40 [127] PIM-CO19 30 0.2-0.3 6100 580 320 10.52 19.10 [127] Cross-linked PIM-1/azide2 (80:20) 25 3.4 219 --- 8 --- 27.40 [128] TRN 35 1.01325 1624 35 62 46 26 [129] TR450 35 10 410 17.08 --- 24 --- [92] TR-PBI (450) 25 --- 1,624 35 --- 46.1 --- [129] TRS 35 1.01325 1591 47 75 34 21 [89,90] TRO-1 35 1.01325 1715 46 97 37 18 [89,90] TRO-6 35 1.01325 4134 122 164 34 25 [89,90] Spiro TR-PBO (6F) 35 1.01325 675 33.75 --- 20 --- [130] cPBO-1 --- 1.01325 5568 252 431 22 13 [96] sPBO-1 --- 1.01325 5903 260 350 23 17 [96] HAB-6-FDA-Pac (TR400) 35 10 211 11.40 --- 18.5 --- [103] PBO (450) 25 1 4201 15.03 --- 28 --- [96] CPBOc (90/10) 35 3.5 1539 64.93 --- 23.7 --- [131] 6FDA-DATRI 35 1.01325 189 6.2 8.1 30.5 23.3 [132] 6-FDA-Durene (2/2) 35 10 612 45 --- 14 --- [133] Original PI-200 35 10 235.28 10.42 --- 22.28 [134] Original PI-425.21 35 10 1302.21 62.52 --- 20.83 --- [134] PPM-α-CD-425 35 10 2423.03 111.67 --- 21.70 --- [134] PPM-β-CD-425 35 10 3112.26 140.25 --- 22.19 --- [134] PPM-c-CD-425 35 10 4211.12 187.66 --- 22.44 --- [134] 4,4ʹ-(hexafluoroisopropylidene)diphthalic anhydride (6FDA)

35 1.01325 360 15 16.5 24 --- [135]

p-polyetherimides 35 1.01325 200 7.6 8.4 26.3 --- [136] 6FDA-pTeMPD 35 10 440 28.2 --- 15.6 --- [137] 6FDA-mTrMPD 35 10 431 26 --- 16.6 --- [137] Poly(ether urethane) PU1 35 10 77.5 11.2 --- 6.9 --- [138] Poly(ether urethane) PU3 35 10 58.8 4.5 --- 13 --- [138] Poly(ether urethane urea) PU2 35 10 197 32.3 --- 6.1 --- [138] Poly(ether urethane urea) PU4 35 10 44.7 2.6 --- 17 --- [138]

References

[1] A.F. Ismail, K.C. Khulbe, T. Matsuura, Gas separation membranes:Polymeric and inorganic, Springer International Publishing, Switzerland, 2015.

[2] R.W. Baker, B.T. Low, Gas separation membrane materials: A perspective, Macromolecules, 47 (2014) 6999–7013. [3] P.Bernardo, E.Drioli, G.Golemme,Membrane gas separation: A review/state of the art, Industrial & Engineering Chemistry

Research, 48(2009) 4638−4663. [4] R.W. Baker, Future directions of membrane gas separation technology, Industrial & Engineering Chemistry Research, 41

(2002) 1393−1411. [5] M. Rezakazemi, A. Ebadi Amooghin, M.M. Montazer-Rahmati, A.F. Ismail, T. Matsuura, State-of-the-art membrane based

CO2 separation using mixed matrix membranes (MMMs): An overview on current status and future directions, Progress in Polymer Science, 39 (2014) 817–861.

[6] R.S. Haszeldine, Carbon capture and storage: how green can black be?, Science 325 (2009) 1647-1652. [7] E. Favre, Carbon dioxide recovery from post-combustion processes: Can gas permeation membranes compete with

absorption?, Journal of Membrane Science, 294 (2007) 50-59. [8] G.T. Rochelle, Amine scrubbing for CO2 capture, Science, 325 (2009) 1652-1654.


363

[9] H. Sanaeepur, A. Kargari, B. Nasernejad, Aminosilane-functionalization of a nanoporous Y-type zeolite for application in a cellulose acetate based mixed matrix membrane for CO2 separation, RSC Advances, 4 (2014) 63966–63976.

[10] P. Luis, T.V. Gerven, B.Van der Bruggen, Recent developments in membrane-basedtechnologies for CO2 capture, Progress in Energy and Combustion Science, 38 (2013) 419-448.

[11] R. Bredesen, K. Jordal, O. Bolland, High-temperature membranes in powergeneration with CO2 capture, Chemical Engineering and Processing: Process Intensification, 43 (2004) 1129-1158.

[12] B.T. Low, L. Zhao, T.C. Merkel, M. Weber, D. Stolten, A parametric study of theimpact of membrane materials and process operating conditions on carbon capture fromhumidified flue gas, Journal of Membrane Science, 431 (2013) 139-155.

[13] A. Fernández-Barquín, C. Casado-Coterillo, M. Palomino, S. Valencia, A. Irabien, Permselectivity improvement in membranes for CO2/N2 separation, Separation and Purification Technology, 157 (2016) 102–111.

[14] Z. Hu, Z. Kang, Y. Qian, Y. Peng, X. Wang, C. Chi, D. Zhao, Mixed matrix membranes containing UiO-66(Hf)-(OH)2 metal−organic framework nanoparticles for efficient H2/CO2 separation, Industrial & Engineering Chemistry Research, In Press, 2016. DOI: 10.1021/acs.iecr.5b04568

[15] H. Sanaeepur, A. Kargari, B. Nasernejad, A. Ebadi Amooghin, M. Omidkhah, A novel Co2+ exchanged zeoliteY/cellulose acetate mixed matrix membrane for CO2/N2 separation, Journal of the Taiwan Institute of Chemical Engineers, 60 (2016) 403–413.

[16] A. EbadiAmooghin, M. Zamani Pedram, M. Omidkhah, R. Yegani, A novel CO2-selective synthesized amine-impregnatedcross-linked polyvinylalcohol/glutaraldehyde membrane: fabrication, characterization, and gas permeationstudy, Greenhouse Gases: Science and Technology, 3 (2013) 378–391.

[17] A. Ebadi Amooghin, H. Sanaeepur, A. Kargari, A. Moghadassi, Direct determination of concentration-dependent diffusion coefficient in polymeric membranes based on the Frisch method, Separation and Purification Technology, 82 (2011) 102–113.

[18] T.C. Merkel, H. Lin, X. Wei, R. Baker, Power plant post-combustion carbon dioxide capture: an opportunity for membranes, Journal of Membrane Science, 359 (2010) 126–139.

[19] N. Du, H.B. Park, M.M. Dal-Cina, M.D. Guiver, Advances in high permeability polymeric membrane materials for CO2 separations, Energy & Environmental Science, 5 (2012) 7306-7322.

[20] R.W. Baker, Membrane technology and applications, John Wiley & Sons, Ltd., West Sussex, England, 2004. [21] S. Sridhar, R.S. Veerapur, M.B. Patil, K.B. Gudasi, T.M. Aminabhavi, Matrimid polyimide membranes for the separation of

carbon dioxide from methane, Journal of applied polymer science, 106 (2007) 1585–1594. [22] M. Zamani Pedram, M. Omidkhah, A. Ebadi Amooghin, R. Yegani, Facilitated transport by amine-mediated

poly(vinylalcohol) membranes for CO2 removal from natural gas, Polymer Engineering Science, 54 (2014) 1268–1279. [23] S. Sridhar, B. Smitha, T.M. Aminabhavi, Separation of carbon dioxide from natural gas mixtures through polymeric

membranes—a review, Separation & Purification Reviews, 36 (2007) 113–174. [24] M. Zamani Pedram, M. Omidkhah, A. Ebadi Amooghin, Synthesis and characterization of diethanolamine-impregnated

cross-linked polyvinylalcohol/glutaraldehyde membranes for CO2/CH4 separation, Journal of Industrial and Engineering Chemistry, 20 (2014) 74–82.

[25] F. Ranjbaran, M. Omidkhah, A. Ebadi Amooghin, The novel Elvaloy4170/functionalized multi-walled carbon nanotubes mixed matrix membranes: Fabrication, characterization and gas separation study, Journal of the Taiwan Institute of Chemical Engineers, 49 (2015) 220–228.

[26] M. Omidkhah, M. Zamani Pedram, A. Ebadi Amooghin, Facilitated transport of CO2 through DEA-mediated poly(vinyl alcohol) membrane cross-linked by formaldehyde, Journal of Membrane Science & Technology, 3 (2013) 119. DOI: 10.4172/2155-9589.1000119

[27] T. Visser, N. Masetto, M. Wessling, Materials dependence of mixed gas plasticization behaviorin asymmetric membranes, Journal of Membrane Science, 306 (2007) 16–28.

[28] C.E. Powell, G.G. Qiao, Polymeric CO2/N2 gas separation membranes for the capture of carbon dioxide from power plant flue gases, Journal of Membrane Science, 279 (2006) 1–49.

[29] A. Kargari, H. Sanaeepur, Application of membrane gas separation processesin petroleum industry, in: S. Sinha, K.K. Pant (Eds.) Advances in petroleum engineering, Studium Press LLC, Houston, USA, 2015, pp. 592–622.

[30] H. Sanaeepur, B. Nasernejad, A. Kargari, Cellulose acetate/nano-porous zeolite mixed matrix membrane for CO2 separation, Greenhouse Gases: Science and Technology, 5 (2015) 291-304.

[31] W.-g. Kim, J.S. Lee, D.G. Bucknall, W.J. Koros, S. Nair, Nanoporous layered silicate AMH-3/cellulose acetate nanocomposite membranes for gas separations, Journal of Membrane Science, 441 (2013) 129-136.

[32] J.K. Ward, Crosslinkable mixed matrix membranes for the purification of natural gas, School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Ph.D. thesis, 2010.

[33] Y. Huang, D.R. Paul, Experimental methods for tracking physical aging of thin glassy polymer films by gas separation, Journal of Membrane Science, 244 (2004) 167–178.

[34] D.F. Sanders, Z.P. Smith, R. Guo, L.M. Robeson, J.E. McGrath, D.R. Paul, B.D. Freeman, Energy-efficient polymeric gas separation membranes for a sustainable future: A review, Polymer, 54 (2013) 4729-4761.

[35] I. Khalilinejad, H. Sanaeepur, A. Kargari, Preparation of poly(ether-6-block amide)/PVC thin film composite membrane for CO2 separation: effect of top layer thickness and operating parameters, Journal of Membrane Science and Research, 1 (2015) 124-129.

[36] L.A. Utracki, Polymer blends handbook, Kluwer Academic Publishers, Dordrecht, The Netherlands, 2002. [37] C.H. Lau, P.T. Nguyen, M.R. Hill, A.W. Thornton, K. Konstas, C.M. Doherty, R.J. Mulder, L. Bourgeois, A.C. Liu, D.J.

Sprouster, J.P. Sullivan, T.J. Bastow, A.J. Hill, D.L. Gin, R.D. Noble, Ending aging in super glassy polymer membranes, Angewandte Chemie, 126 (2014) 5426-5430.

[38] Z. Mao, X. Jie, Y. Cao, L. Wang, M. Li, Q. Yuan, Preparation of dual-layer cellulose/polysulfone hollow fiber membrane and its performance for isopropanol dehydration and CO2 separation, Separation and Purification Technology, 77 (2011) 179-184.


364

[39] A.J.M. Valente, A.Y. Polishchuk, H.D. Burrows, V.M.M. Lobo, Permeation of water as a tool for characterizing the effect of solvent, film thickness and water solubility in cellulose acetate membranes, Europian Polymer Journal, 41 (2005) 275-281.

[40] M.A. Zamiri, A. Kargari, H. Sanaeepur, Ethylene vinyl acetate/poly(ethylene glycol) blend membranes for CO2/N2 separation, Greenhouse Gases: Science and Technology, 5 (2015) 668–681.

[41] L.S. White, Evolution of natural gas treatment with membrane systems, in: Y. Yampolskii, B.D. Freeman (Eds.) Membrane gas separation, John Wiley & Sons, Ltd., West Sussex, United Kingdom, 2010, pp. 313–332.

[42] C.A. Scholes, S.E. Kentish, G.W. Stevens, Effects of minor components in carbon dioxide capture using polymeric gas separation membranes, Separation and Purification Reviews, 38 (2009) 1–44.

[43] S.R. Reijerkerk, K. Nijmeijer, C.P. Ribeiro Jr., B.D. Freeman, M. Wessling, On the effects of plasticization in CO2/light gas separation using polymeric solubility selective membranes, Journal of Membrane Science, 367 (2011) 33–44.

[44] M. Wessling, S. Schoeman, T. van der Boomgaard, C.A. Smolders, Plasticization of gas separation membranes, Gas Separation and Purification, 5 (1991) 222-228.

[45] G.C. Kapantaidakis, G.H. Koops, M. Wessling, S.P. Kaldis, G.P. Sakellaropoulos, CO2 plasticization of polyethersulfone/polyimide gas-separation membranes, AIChE Journal, 49 (2003) 1702-1711.

[46] O. Hosseinkhani, A. Kargari, H. Sanaeepur, Facilitated transport of CO2 through Co(II)-S-EPDM ionomer membrane, Journal of Membrane Science, 469 (2014) 151–161.

[47] A. Ebadi Amooghin, H. Sanaeepur, A. Moghadassi, A. Kargari, D. Ghanbari, Z.Sheikhi Mehrabadi, Modification of ABS membrane by PEG for capturing carbon dioxide from CO2/N2 streams, Separation Science and Technology, 45 (2010) 1385-1394.

[48] H. Sanaeepur, A. Ebadi Amooghin, A. Moghadassi, A. Kargari, Preparation and characterization of acrylonitrile-butadiene-styrene/poly(vinyl acetate) membrane for CO2 removal, Separation and Purification Technology, 80 (2011) 499-508.

[49] H. Sanaeepur, A. Ebadi Amooghin, A. Moghadassi, A. Kargari, S. Moradi, D. Ghanbari, A novel acrylonitrile-butadiene-styrene/poly(ethylene glycol) membrane: preparation, characterization and gas permeation study, Polymers for Advanced Technologies, 23 (2012) 1207–1218.

[50] H.A. Mannan, H. Mukhtar, T. Murugesan, R. Nasir, D.F. Mohshim, A. Mushtaq, Recent applications of polymer blends in gas separation membranes, Chemical Engineering and Technology, 36 (2013) 1-10.

[51] L.M. Robeson, Polymer blends in membrane transport processes, Industrial & Engineering Chemistry Research, 49 (2010) 11859–11865.

[52] A. Kargari, H. Sanaeepur, A comparison between PEG and PVAc as ABS polymeric membrane modifiers for CO2 separation from flue gases, Advanced Chemical Engineering Research, 3 (2014) 64–71.

[53] A. Mondal, B. Mandal, Novel CO2-selective cross-linked poly(vinyl alcohol)/polyvinylpyrrolidone blend membrane containing amine carrier for CO2−N2 separation: Synthesis, characterization, and gas permeation study, Industrial & Engineering Chemistry Research, 53 (2014) 19736-19746.

[54] A. Taguet, P. Cassagnau, J.M. Lopez-Cuesta, Structuration, selective dispersion and compatibilizing effect of (nano) fillers in polymer blends, Progress in Polymer Science, 39 (2014) 1526-1563.

[55] S. Bandehali, A. Kargari, A. Moghadassi, H. Saneepur, D. Ghanbari, Acrylonitrile-butadiene-styrene/poly(vinyl acetate)/nano-silica mixed matrix membrane for He/CH4 separation, Asia-Pacific Journal of Chemical Engineering, 9 (2014) 638–644.

[56] W. Qiu, C.-C. Chen, L. Xu, L. Cui, D.R. Paul, W.J. Koros, Sub-Tg cross-linking of a polyimide membrane for enhanced CO2 plasticization resistance for natural gas separation, Macromolecules, 44 (2011) 6046–6056.

[57] C.S.K. Achoundong, N. Bhuwania, S.K. Burgess, O. Karvan, J.R. Johnson, W.J. Koros, Silane modification of cellulose acetate dense films as materials for acid gas removal, Macromolecules, 46 (2013) 5584-5594.

[58] A.F. Ismail, W. Lorna, Penetrant-induced plasticization phenomenon in glassy polymers for gas separation membrane, Separation and Purification Technology, 27 (2002) 173-194.

[59] Y. Maeda, D.R. Paul, Effect of antiplasticization on gas sorption and transport. I. Polysulfone, Journal of Polymer Science Part B: Polymer Physics, 25 (1987) 957-980.

[60] Y. Maeda, D.R. Paul, Effect of antiplasticization on gas sorption and transport. II. Poly (phenylene oxide), Journal of Polymer Science Part B: Polymer Physics, 25 (1987) 981-1003.

[61] W. Ogieglo, Z.P. Madzarevic, M.J.T. Raaijmakers, T.J. Dingemans, N.E. Benes, High-pressure sorption of carbon dioxide and methane in all-aromatic poly(etherimide)-based membranes, Journal of Polymer Science, Part B: Polymer Physics, 54 (2016) 986–993.

[62] J.D. Wind, S.M. Sirard, D.R. Paul, P.F. Green, K.P. Johnston, W.J. Koros, Relaxation dynamics of CO2 diffusion, sorption, and polymer swelling for plasticized polyimide membranes, Macromolecules, 36 (2003) 6442-6448.

[63] J.E. Mark, H.R. Allcock, R. West, Inorganic polymers, 2nd ed., Oxford University Press, Inc., New York, 2005. [64] Y. Wang, H. Li, G. Dong, C. Scholes, V. Chen, Effect of fabrication and operation conditions on CO2 separation performance

of PEO–PA block copolymer membranes, Industrial & Engineering Chemistry Research, 54 (2015) 7273-7283. [65] A. Wolińska-Grabczyk, A. Jankowski, High performance membrane materials for gas separation, Copernican Letters, 6

(2015) 11-16. [66] P.M. Budd, N.B.McKeown, Highly permeable polymers for gas separation membranes, Polymer Chemistry, 1 (2010) 63–68. [67] N.B. McKeown, P.M. Budd, Exploitation of intrinsic microporosity in polymer-basedmaterials, Macromolecules, 43 (2010)

5163–5176. [68] S. Harms, K. Raetzke, F. Faupel, N. Chaukura, P.M. Budd, W. Egger, L. Ravelli, Aging andfree volume in a polymer of

intrinsic microporosity (PIM-1),The Journal of Adhesion, 88 (2012) 608–619. [69] T. Koschine, K. Raetzke, F. Faupel, M.M. Khan,T Emmler, V. Filiz, V. Abetz, L. Ravelli, W. Egger, Correlation of gas

permeation and free volume in new and used high free volume thinfilm composite membranes. Journal of Polymer Science, Part B: Polymer Physics, 53 (2015) 213–217.


365

[70] K. Althumayri, W.J. Harrison, Y. Shin, J.M. Gardiner, C. Casiraghi, P.M. Budd, P. Bernardo, G. Clarizia, J.C. Jansen, The influence of few-layer graphene on the gas permeability of the high-free-volume polymer PIM-1, Philosophical Transactions of the Royal Society A: Mathematical, Physical & Engineering Sciences, 374 (2016) 20150031.

[71] N.B. McKeown, S. Makhseed, P.M. Budd, Phthalocyanine-based nanoporous network polymers,Chemical Communications, (2002) 2780–2781.

[72] N.B. McKeown, S. Hanif, K. Msayib, C.E. Tattershall, P.M. Budd, Porphyrin-based nanoporous network polymers, Chemical Communications, (2002) 2782–2783.

[73] P.M. Budd, B.S. Ghanem, S. Makhseed, N.B. McKeown,K.J. Msayib, C.E. Tattershall, Polymers of intrinsic microporosity (PIMs): robust, solution-processable, organic nanoporous materials, Chemical Communications, (2004), 230–231.

[74] P.M. Budd, E.S. Elabas, B.S. Ghanem, S. Makhseed,N.B. McKeown, K.J. Msayib, C.E. Tattershall, D. Wang, Solution-processed, organophilic membrane derived from a polymer of intrinsic microporosity, Advanced Materials, 16 (2004) 456–459.

[75] J. Song, N. Du, Y. Dai, G.P. Robertson, M.D. Guiver, S. Thomas, I. Pinnau, Linear high molecular weight ladder polymers by optimized polycondensation of tetrahydroxytetramethylspirobisindane and 1,4-dicyanotetrafluorobenzene, Macromolecules, 41 (2008) 7411–7417.

[76] N. Du, J. Song, G.P. Robertson, I. Pinnau, M.D. Guiver,Linear high molecular weight ladder polymer via fast polycondensation of 5,5′,6,6′-Tetrahydroxy-3,3,3′,3′-tetramethylspirobisindane with 1,4-dicyanotetrafluorobenzene, Macromolecular Rapid Communications, 29 (2008) 783–788.

[77] N.B. McKeown, P.M. Budd, Polymers of intrinsic microporosity (PIMs): organic materials for membrane separations, heterogeneous catalysis and hydrogen storage, Chemical Society Reviews, 35 (2006) 675–683.

[78] N. Du, G.P. Robertson, I. Pinnau, M.D. Guiver,Polymers of intrinsic microporosity with dinaphthyl and thianthrene segments, Macromolecules, 43 (2010) 8580–8587.

[79] T. Emmler, K. Heinrich, D. Fritsch, P.M. Budd, N. Chaukura,D. Ehlers, K. Ratzke, F. Faupel, Free volume investigation of polymers of intrinsic microporosity (PIMs): PIM-1 and PIM1 copolymers incorporating ethanoanthracene units, Macromolecules, 43 (2010) 6075–6084.

[80] B.S. Ghanem, N.B. McKeown, P.M. Budd, D. Fritsch,Polymers of intrinsic microporosity derived from bis(phenazyl) monomers,Macromolecules, 41 (2008) 1640–1646.

[81] P.M. Budd, N.B. McKeown, D. Fritsch, Polymers of intrinsic microporosity (PIMs): High free volume polymers for membrane applications, Macromolecular Symposia,245–246 (2006) 403–405.

[82] N. Du, G.P. Robertson, I. Pinnau, S. Thomas, M.D. Guiver, Copolymers of intrinsic microporosity based on 2,2′,3,3′-tetrahydroxy-1,1′-dinaphthyl, Macromolecular rapid communications, 30 (2009) 584–588.

[83] M. Carta, K.J. Msayib, P.M. Budd, N.B. McKeown, Novel spirobisindanes for use as precursors to polymers of intrinsic microporosity, Organic Letters, 10 (2008) 2641–2643.

[84] R. Short, M. Carta, C.G. Bezzu, D. Fritsch, B.M. Kariuki, N.B. McKeown,Hexaphenylbenzene-based polymers of intrinsic microporosity, Chemical Communications, 47 (2011) 6822–6824.

[85] N. Du, G.P. Robertson, J. Song, I. Pinnau, M.D. Guiver, High-performance carboxylated polymers of intrinsic microporosity (PIMs) with tunable gas transport properties, Macromolecules, 42 (2009) 6038–6043.

[86] N. Du, G.P. Robertson, I. Pinnau, M.D. Guiver, Polymers of intrinsic microporosity derived from novel disulfone-based monomers, macromolecules, 42 (2009) 6023–6030.

[87] N. Du, G.P. Robertson, J. Song, I. Pinnau, S. Thomas, M.D. Guiver, Polymers of intrinsic microporosity containing trifluoromethyl andphenylsulfone groups as materials for membrane gas separation, Macromolecules, 41 (2008) 9656–9662.

[88] N. Du, H.B. Park, G.P. Robertson, M.M. Dal-Cin, T. Visser, L. Scoles, M.D. Guiver, Polymer nanosieve membranes for CO2-capture applications, Nature materials, 10 (2011) 372–375.

[89] H.B. Park, C.H. Jung, Y.M. Lee, A. J. Hill, S.J. Pas, S.T. Mudie,E. van Wagner, B.D. Freeman, D.J. Cookson, Polymers with cavities tuned for fast selective transport of small molecules and ions, Science, 318 (2007) 254–258.

[90] H.B. Park, S.H. Han, C.H. Jung, Y.M. Lee, A.J. Hill, Thermally rearranged (TR) polymer membranes for CO2 separation, Journal of Membrane Science, 359 (2010) 11–24.

[91] Y. Jiang, F.T. Willmore, D.F. Sanders, Z.P. Smith, C.P. Ribeiro, C.M. Doherty, A. Thornton, A.J. Hill, B.D. Freeman, I.C. Sanchez, Cavity size, sorption and transport characteristics of thermally rearranged (TR) polymers, Polymer, 52(2011)2224-2254.

[92] D.F. Sanders, Z.P. Smith, C.P. Ribeiro, R. Guo, J.E. McGrath, D.R. Paul, B.D. Freeman, Gas permeability, diffusivity, and free volume of thermally rearranged polymers based on 3,3′-dihydroxy-4,4′-diamino-biphenyl (HAB) and 2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), Journal of Membrane Science, 409-410 (2012) 232-241.

[93] Z.P. Smith, D.F. Sanders, C.P. Ribeiro, R. Guo, B.D. Freeman, D.R. Paul,J.E. McGrath, S. Swinnea, Gas sorption and characterization of thermally rearranged polyimides based on 3,3′-dihydroxy-4,4′-diamino-biphenyl (HAB) and 2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), Journalof Membrane Science, 415-416 (2012) 558-567.

[94] Z.P. Smith, R.R. Tiwari, T.M. Murphy, D.F. Sanders, K.L. Gleason, D.R. Paul, B.D. Freeman, Hydrogen sorption in polymers for membrane applications, Polymer, 54 (2013) 3026-3037.

[95] C.H. Jung, J.E. Lee, S.H. Han, H.B. Park, Y.M.Lee, Highly permeable and selective poly(benzoxazole-co-imide) membranes for gas separation, Journal of Membrane Science, 350 (2010) 301-309.

[96] J.I. Choi, C.H. Jung, S.H. Han, H.B. Park, Y.M. Lee, Thermally rearranged (TR) poly(benzoxazole-co-pyrrolone) membranes tuned for high gas permeability and selectivity,Journal of Membrane Science, 349 (2010) 358-368.

[97] S.H. Han, N. Misdan, S. Kim, C.M. Doherty, A.J. Hill, Y.M. Lee, Thermally rearranged (TR) polybenzoxazole: Effects of diverse imidization routes on physical properties and gas transport behaviors, Macromolecules, 43 (2010) 7657-7667.

[98] G.L.Tullos, L.J.Mathias, Unexpected thermal conversion of hydroxy-containing polyimides to polybenzoxazoles, Polymer, 40 (1999) 3463-3468.


366

[99] G.L.Tullos, J.M. Powers, S.J. Jeskey, L.J.Mathias, Thermal conversion of hydroxy-containing imides to benzoxazoles: Polymer and model compound study, Macromolecules, 31 (1999) 3598-3612.

[100] R. Guo, D.F. Sanders, Z.P. Smith, B.D. Freeman, D.R. Paul, J.E.McGrath, Synthesis and characterization of thermally rearranged (TR) polymers: influence of ortho-positioned functional groups of polyimide precursors on TR process and gas transport properties, Journal of Materials Chemistry A, 1 (2013) 262-272.

[101] L.M. Robeson, The upper bound revisited, Journal of Membrane Science, 320 (2008) 390-400. [102] A. Ebadi Amooghin, M. Omidkhah, A. Kargari, Enhanced CO2 transport properties of membranes by embedding nano-

Porous zeolite particles into Matrimid®5218 matrix, RSC Advances, 5 (2015) 8552–8565. [103] J. Ahmad, M.B. Hagg, Development of Matrimid/zeolite 4A mixed matrix membranes using low boiling point solvent,

Separation and Purification Technology, 115 (2013) 190–197. [104] S.L. Liu, L. Shao, M. L. Chua, C. H. Lau, H. Wang, S. Quan, Recent progress in the design of advanced PEO containing

membranes for CO2 removal, Progress in Polymer Science, 38 (2013) 1089–1120. [105] M. Loloei, M. Omidkhah, A. Moghadassi, A. Ebadi Amooghin, Preparation and characterization of Matrimid®5218 based

binary and ternary mixed matrix membranes for CO2 separation, International Journal of Greenhouse Gas Control, 39 (2015) 225–235.

[106] M. Loloei, A. Moghadassi, M. Omidkhah, A. Ebadi Amooghin, Improved CO2 separation performance of Matrimid®5218 membrane by addition of low molecular weight polyethylene glycol, Greenhouse Gases: Science and Technology, 5 (2015) 530–544.

[107] A. Ebadi Amooghin, M. Omidkhah, A. Kargari, The effects of aminosilane grafting on NaY zeolite–Matrimid®5218 mixed matrix membranes for CO2/CH4 separation, Journal of Membrane Science, 490 (2015) 364–379.

[108] A. Ebadi Amooghin, M. Omidkhah, H. Sanaeepur, A. Kargari, Preparation and characterization of Ag+ ion-exchanged zeolite-Matrimid®5218 mixed matrix membrane for CO2/CH4 separation, Journal of Energy Chemistry, 25 (2016) 450-462.

[109] O.M. Ekiner, G.K. Fleming, Process for enhancing the selectivity of mixed gas separations, U.S. Patent 5,168, 332, 1997. [110] D.T. Coker, B.D. Freeman, G.K. Fleming, Modeling multicomponent gas separation using hollow-fiber membrane

contactors, AIChE Journal, 44 (1998) 1289-1302. [111] P. Hao, G.G. Lipscomb, The effect of sweep uniformity on gas dehydration module performance, in: Y. Yampolskii, B.D.

Freeman (Eds.) Membrane gas separation, John Wiley & Sons, Ltd., West Sussex, United Kingdom, 2010, p.p. 333-353. [112] J.M.S. Henis, M.K. Tripodi, Composite hollow fiber membranes for gas separation: the resistance model approach, Journal of

Membrane Science, 8 (1981) 233-246. [113] J.M.S. Henis, M.K. Tripodi, The developing technology of gas separating membranes, Science, 220 (1983) 11-17. [114] J. Lemanski, G.G. Lipscomb, Effect of fiber variation on the performance of cross-flow hollow fiber gas separation modules,

Journal of Membrane Science, 153 (1999) 33-43. [115] B. Lihong, G.G. Lipscomb, Effect of random fiber packing on the performance of shell-fed hollow-fiber gas separation

modules, Desalination, 146 (2002) 243-248. [116] J.D. Wind, C. Staudt-Bickel, D.R. Paul, W.J. Koros, Solid-state covalent cross-linking of polyimide membranes for carbon

dioxide plasticization reduction, Macromolecules, 36 (2003) 1882-1888. [117] A.W. Rice, M.K. Murphy, Gas dehydration membrane apparatus, U.S. Patent, 4,783,201, 1988. [118] M.K. Murphy, A.W. Rice, J.J. Freeman, Process for producing high quality gas for instrumentation applications using gas

separation membranes, U.S. Patent, 4,793, 830, 1988. [119] T.C. Merkel, M. Zhou, R.W. Baker, Carbon dioxide capture with membranes at an IGCC power plant, Journal of Membrane

Science, 389 (2012) 441-450. [120] A. Sengupta, K.K. Sirkar, Analysis and design of membrane permeators for gas separation, in: R.D. Noble, S.A. Stern (Eds.)

Membrane separations technology: principles and applications, Amsterdam, Elsevier, 1995, p.p. 499-553. [121] G. George, N. Bhoria, S. Al Hallaq, A. Abdala, V. Mittal, Polymer membranes for acid gas removal from natural gas,

Separation and Purification Technology, 158 (2016) 333–356. [122] H. Li, B.D. Freeman, O.M. Ekiner, Gas permeation properties of poly(urethaneurea)s containing different polyethers, Journal

of Membrane Science, 369 (2011) 49–58. [123] J.W. Simmons, Block polyurethane-ether and polyurea-ether gas separation membranes, U.S. Patent 6,843, 829, 2005. [124] P.M. Budd, N.B. McKeown, B.S. Ghanem, K.J. Msayib, D. Fritsch, L. Starannikova, N. Belov, O. Sanfirova, Y. Yampolskii,

V. Shantarovich, Gas permeation parameters and other physicochemical properties of a polymer of intrinsic microporosity: Polybenzodioxane PIM-1, Journal of Membrane Science, 325 (2008) 851–860.

[125] P.M. Budd, K.J. Msayib, C.E. Tattershall, B.S. Ghanem, K.J. Reynolds, N.B. McKeown, D. Fritsch, Gas separation membranes from polymers of intrinsic microporosity, Journal of Membrane Science, 251 (2005) 263–269.

[126] B.S. Ghanem, N.B. McKeown, P.M. Budd, N.M. Al-Harbi, D. Fritsch, K. Heinrich, L. Starannikova, A. Tokarev, Y. Yampolskii, Synthesis, characterization, and gas permeation properties of a novel group of polymers with intrinsic microporosity: PIM-polyimides, Macromolecules, 42 (2009) 7881–7888.

[127] H. Lin, B.D. Freeman, Materials selection guidelines for membranes that remove CO2 from gas mixtures, Journal of Molecular Structure, 739 (2005) 57–74.

[128] N. Du, M.M. Dal-Cin, I. Pinnau, A. Nicalek, G.P. Robertson, M.D. Guiver, Azide-based cross-linking of polymers of intrinsic microporosity (PIMs) for condensable gas separation, Macromolecular rapid communications, 32 (2011) 631–636.

[129] S.H. Han, J.E. Lee, K.-J. Lee, H.B. Park, Y.M. Lee, Highly gas permeable and microporous polybenzimidazole membrane by thermal rearrangement, Journal of Membrane Science, 357 (2010) 143–151.

[130] S. Li, H.J. Jo, S.H. Han, C.H. Park, S. Kim, P.M. Budd, Y.M. Lee, Mechanically robust thermally rearranged (TR) polymer membranes with spirobisindane for gas separation, Journal of Membrane Science, 434 (2013) 137-147.

[131] Y.F. Yeong, H. Wang, K.P. Pramoda, T.S. Chung, Thermal induced structural rearrangement of cardo-copolybenzoxazole membranes for enhanced gas transport properties, Journal of Membrane Science, 397 (2012) 51-65.


367

[132] Y.J. Cho, H.B. Park, High performance polyimide with high internal free volume elements, Macromolecular rapid communications, 32 (2011) 579–586.

[133] Y. Xiao, T.-S. Chung, H.M. Guan, M.D. Guiver, Synthesis, cross-linking and carbonization of co-polyimides containing internal acetylene units for gas separation, Journal of Membrane Science, 302 (2007) 254-264.

[134] M. Askari, Y. Xiao, P. Li, T.-S. Chung, Natural gas purification and olefin/paraffin separation using crosslinkable 6FDA-Durene/DABA co-polyimides grafted with a, b, and c-cyclodextrin, Journal of Membrane Science, 390 (2012) 141-151.

[135] M. Al-Masei, H.R. Kricheldorf, D. Fritsch, New polyimides for gas separation. 1. Polyimides derived from substituted terphenylenes and 4,4’-(hexafluoroisopropylidene)diphthalic Anhydride, Macromolecules, 32 (1999) 7853–7858.

[136] M. Al-Masei, D. Fritsch, H.R. Kricheldorf, New polyimides for gas separation. 2. Polyimides derived from substituted catechol bis(etherphthalic anhydride)s, Macromolecules, 33 (2000) 7127–7135.

[137] K. Tanaka, M. Okano, H. Toshino, H. Kita, K.-I. Okamoto, Effect of methyl substituents on permeability and permselectivity of gases in polyimides prepared from methyl-substituted phenylenediamines, Journal of Polymer Science Part B: Polymer Physics, 30 (1992) 907–914.

[138] G. Chatterjee, A. Houde, S. Stern, Poly (ether urethane) and poly (ether urethane urea) membranes with high H2S/CH4 selectivity, Journal of Membrane Science, 135 (1997) 99–106.


368

New advances in polymeric membranes for CO separation · 2016-06-15 · New advances in polymeric...

Documents

Transcript of New advances in polymeric membranes for CO separation · 2016-06-15 · New advances in polymeric...