CO2-selective Membranes Research Articles

A review on the emerging applications of cellulose, cellulose derivatives and nanocellulose in carbon capture

Carbon capture can be implemented at a large scale only if the CO2 selective materials are abundantly available at low cost. Since the sustainable requirement also elevated, the low-cost and biodegradable cellulosic materials are developed into CO2 selective adsorbent and membranes recently. The applications of cellulose, cellulosic derivatives and nanocellulose as CO2 selective adsorbents and membranes are reviewed here. The fabrication and modification strategies are discussed besides comparing their CO2 separation performance. Cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) isolated from cellulose possess a big surface area for mechanical enhancement and a great number of hydroxyl groups for modification. Nanocellulose aerogels with the large surface area were chemically modified to improve their selectivity towards CO2. Even with the reduction of surface area, amino-functionalized nanocellulose aerogels exhibited the satisfactory chemisorption of CO2 with a capacity of more than 2 mmol/g was recorded. Inorganic fillers such as silica, zeolite and MOFs were further incorporated into nanocellulose aerogels to enhance the physisorption of CO2 by increasing the surface area. Although CO2 adsorbents developed from cellulose and cellulose derivatives were less reported, their applications as the building blocks of CO2 separation membranes had been long studied. Cellulose acetate membranes were commercialized for CO2 separation, but their separation performance could be further improved with silane or inorganic filler. CNCs and CNFs enhanced the CO2 selectivity and permeance through polyvinyl alcohol coating on membranes, but only CNF membranes incorporated with MOFs were explored so far. Although some of these membranes surpassed the upper-bound of Robeson plot, their stability should be further investigated.

Modification of CO2-selective mixed matrix membranes by a binary composition of poly(ethylene glycol)/NaY zeolite

Mixed matrix membranes (MMMs) were prepared by Pebax polymers incorporating with two dopants of poly(ethylene glycol) (PEG) and NaY zeolite. The surface morphology, chemical groups, microstructure, thermal properties and gas separation performance of as-obtained membranes were characterized by Scanning Electron Microscope, Infrared Spectroscopy, X-ray Diffraction, Thermogravimetry and Differential Scanning Calorimetry, and gas permeation technology, respectively. The effects of NaY amount, PEG function, permeation temperature and permeation pressure on the microstructure and properties of MMMs were investigated. The results showed that the addition of PEG as secondary composition obviously improved the compatibility of NaY and membrane matrix, and significantly elevated the CO2 permeability and CO2/N2 selectivity. The MMMs prepared by incorporating 20 wt% PEG and 30 wt% NaY zeolite in starting materials exhibited the maximum CO2/N2 selectivity of 107.9 together with the CO2 permeability of 172.6 Barrer. For CO2/N2 mixed gas, the designed membrane could directly enrich the concentration of CO2 from 15% to 96.7% by one step.

CO2-selective zeolitic imidazolate framework membrane on graphene oxide nanoribbons: experimental and theoretical studies

A CO2 selective ZIF-8 membrane can be fabricated on a graphene oxide nanoribbon coated polymeric support with a CO2 permeance of 7.8 × 10−9 mol m−2 Pa−1 s−1 and a CO2/CH4 selectivity of 27.

Highly CO2 selective mixed matrix membranes of polysulfone based on hetaryl modified SBA-16 particles

Mixed matrix membranes were prepared by incorporating pyrazole functionalized SBA-16 type mesoporous silica as filler in polysulfone (PSf) matrix. The structure, morphology, and porosity of functionalized filler were confirmed by Fourier transform infrared (FTIR) spectra, scanning electron microscope (SEM) images, 13C NMR spectra and N2 adsorption-desorption analysis. A good uniform interaction of filler with polymer matrix was observed for all membranes. The porosity of filler enhanced the CO2 gas diffusivity through the membrane leading to increased CO2 permeability of up to 14.43 Barrer (116% increase) at the highest filler loading of 30%. The presence of CO2-philic functional groups resulted in a simultaneous increase in both ideal and mixed gas CO2/N2 selectivity of 42.44 and 46.13 respectively (68.34% and 87.06% increase respectively), compared to non-functionalized filler).

Membrane processes for CO2 removal and fuel utilization enhancement for solid oxide fuel cells

Incomplete oxidation on the anode side of a solid oxide fuel cell (SOFC) leaves a considerable amount of unused fuel (e.g., H2 and CO) in the anode exhaust. In order to enhance fuel utilization, CO2-selective membranes can be employed to remove the CO2 in the anode exhaust before returning the recovered fuel to the SOFC. In this study, two membrane processes have been designed for integration with a SOFC system, one with an air sweep (SOFC-MBair) and the other with a vacuum (SOFC-MBvac), on the permeate side. The transport properties of developed membranes were applied to the processes, and techno-economic analysis (TEA) was carried out to estimate the CO2 removal cost of each process. The parameters investigated were the anode exhaust recycle percentage, stack fuel utilization of the SOFC, power output, as well as the area and transport properties of the membranes. Notably, at 100% anode exhaust recycle, the system fuel utilization can be boosted to >99% for both processes. By tuning the stack fuel utilization, a steam-to-carbon ratio above 1.5 is achievable. It was found that the SOFC-MBvac process can achieve a lower CO2 removal cost than the SOFC-MBair process. For the SOFC-MBvac process, by considering the value of the recovered fuel, the CO2 removal cost not only can be fully rebated by the recovered fuel value, but also there is a profit of about $38 per tonne of CO2 captured. Moreover, by taking into account a CO2 sale price of $40/tonne for enhanced oil recovery, a profit of about $66 per tonne of CO2 captured may be achieved. Furthermore, more cost reduction or profit is attainable by developing membranes with higher CO2 permeances. In addition, a zero-carbon electricity generation can be achieved by the SOFC-MBvac process.

Modification of Poly(4-methyl-2-pentyne) in the Supercritical Fluid Medium for Selective Membrane Separation of CO2 from Various Gas Mixtures.

The modification of highly permeable films of brominated 1,2-disubstituted polyacetylene, poly(4-methyl-2-penthyne), via incorporation of in situ formed butylimidazolium bromide is reported for the first time. Principal possibility and efficiency of supercritical CO2 and CHF3 use as reaction media for the corresponding process, namely for quaternization of butylimidazole by brominated polymer are revealed. As a result, we prepared new membrane materials possessing promising properties such as stability toward organic solvents, good mechanical properties and significantly improved CO2-selectivity while maintaining gas permeability at high values. Comparative analysis of the results allowed us to determine content and conditions for the incorporation of butylimidazolium groups optimal for most efficient separation of CO2 from industrial gas mixtures. These results are of interest for the designing of new CO2 selective membranes.

Sorption-enhanced thin film composites with metal-organic polyhedral nanocages for CO2 separation

The atom transfer radical polymerization (ATRP)-based continuous assembly of polymers (CAP) is a promising approach for fabricating thin film composite (TFC) membranes for high flux. Here, we report the preparation of CO2-selective TFC mixed matrix membranes (MMMs) by incorporating different amounts of [Cu24(m-bdc)24(EG)3(DMF)12] (EG3-MOP) nanocages (e.g., 2.5, 5, and 10 wt%) as CO2-philic fillers in a poly(poly(ethylene glycol) dimethacrylate glycol) dimethacrylate (PEG9DMA) matrix via the ATRP-based CAP technique. The EG3-MOP nanocages are homogeneously distributed in the PEG9DMA matrix with a good compatibility between them at up to 5 wt% of EG3-MOP nanocages due to the hydrophilic interactions between the triethylene oxide tails of EG3-MOP and the PEG of the PEG9DMA matrix. Additionally, both CO2 permeance and CO2/N2 selectivity increased with increasing contents of EG3-MOP nanocages up to 5 wt% via a gradual increase in CO2 solubility because of the favorable interaction of both unsaturated Cu(II) sites and triethylene oxide in EG3-MOP with CO2. In particular, the EG3-MOP/PEG9DMA (5/95 wt/wt) TFC-MMM enhanced both CO2 permeance and CO2/N2 permselectivity relative to those of the pristine PEG9DMA membrane by 45 and 50%, respectively, attaining a CO2 permeance of 448 GPU and a CO2/N2 selectivity of 30. In addition, it exhibited a good CO2/N2 separation performance under equimolar mixed gas conditions at 35 °C, further supporting that our TFC-MMMs fabricated via the ATRP-based CAP technique are attractive for CO2 separation.

The novel micro-phase separated CO2-selective mixed matrix membranes (MMMs) modified with ester group by EPEG

In this paper, ethyl phthalyl ethyl glycolate (EPEG) was first introduced into Pebax to prepare Pebax/EPEG MMMs for CO2 separation. The thermal properties and the gas permeation properties of the MMMs were investigated. The micro-nano structure of the MMMs and the interaction between Pebax and EPEG were studied with fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The compatibility of Pebax and EPEG was characterized with FTIR-mapping and DSC. The location and distribution of liquid EPEG was studied with SEM and confirmed visually by cryo-SEM. The strength of hydrogen bonding interaction in the MMMs was characterized by Kwei equation with a parameter q. Pebax and EPEG were almost miscible in the MMMs at the molecular level when the EPEG content was not higher than 20 wt.%, and then micro-phase separation happened at higher EPEG content. The incorporation of EPEG not only enhanced the diffusion coefficients but also the solubility coefficients of the penetrants through the MMMs. The occurrence of micro-phase separation rendered a greater degree of permeability increase. For the MMMs with EPEG content of 60 wt.%, the CO2 permeability was almost 400 Barrer companied with CO2/N2 selectivity of 30. The CO2 permeability was three times that of the pristine Pebax, indicating the good CO2/N2 separation performance of Pebax/EPEG MMMs.

Pebax® 2533/Graphene Oxide Nanocomposite Membranes for Carbon Capture.

In this work, the behavior of new GO-based mixed matrix membranes was tested in view of their use as CO2-selective membrane in post combustion carbon capture applications. In particular, the new materials were obtained by mixing of Pebax® 2533 copolymer with different types of graphene oxide (GO). Pebax® 2533 has indeed lower selectivity, but higher permeability than Pebax® 1657, which is more commonly used for membranes, and it could therefore benefit from the addition of GO, which is endowed with very high selectivity of CO2 with respect to nitrogen. The mixed matrix membranes were obtained by adding different amounts of GO, from 0.02 to 1% by weight, to the commercial block copolymers. Porous graphene oxide (PGO) and GO functionalized with polyetheramine (PEAGO) were also considered in composites produced with similar procedure, with a loading of 0.02%wt. The obtained films were then characterized by using SEM, DSC, XPS analysis and permeability experiments. In particular, permeation tests with pure CO2 and N2 at 35°C and 1 bar of upstream pressure were conducted for the different materials to evaluate their separation performance. It has been discovered that adding these GO-based nanofillers to Pebax® 2533 matrix does not improve the ideal selectivity of the material, but it allows to increase CO2 permeability when a low filler content, not higher than 0.02 wt%, is considered. Among the different types of GO, then, porous GO seems the most promising as it shows CO2 permeability in the order of 400 barrer (with an increase of about 10% with respect to the unloaded block copolymer), obtained without reducing the CO2/N2 selectivity of the materials, which remained in the order of 25.

UV irradiation-assisted cross-linking of high molecular weight poly (ethylene oxide) with poly (ethylene glycol) diacrylate to prepare CO2 selective membranes

In this work, the high molecular weight poly (ethylene oxide) (PEO) was cross-linked under UV irradiation to decrease its crystallinity in order to prepare a high-performance CO2-selective membrane. Poly (ethylene glycol) diacrylate (PEGDA) containing CO2-philic ether oxygen group was used as both photo-initiator and cross-linking agent. It was found that the crystallinity degree from 82.4% for the neat PEO membrane decreased to 65.4% for the cross-linked PEO membrane by the proposed cross-linking technique. The observations indicated that the structural and gas separation properties of the cross-linked PEO membranes strongly depend on the PEGDA concentration and UV irradiation time. When the PEGDA concentration was between 3 and 7 %wt and at UV irradiation time of 30 min, the prepared membrane overcame Robeson upper bound and indicated a fairly good separation performance in the case of CO2 separation from N2, compared to the similar cross-linked PEG-based membranes in the literature.

Fluoride- and hydroxide-containing CO2-selective membranes for improving H2 utilization of solid oxide fuel cells

Solid oxide fuel cells (SOFCs) have been commercialized due to their ability to provide a reliable energy supply at a high efficiency. However, because of the incomplete oxidation on the anode side, there is still a considerable amount of unused fuel (e.g., H2 and CO) present in the anode exhaust. A CO2-selective membrane was proposed to remove CO2 in the anode exhaust and recycle the retained H2 and CO back to the SOFC. The challenge lies in maintaining a high CO2/H2 selectivity (>100) and a good CO2 permeance (>100 GPU) at an operating temperature of 120 °C. Earlier studies have yielded facilitated transport membranes that employed tetramethylammonium hydroxide (TMAOH) as the mobile carrier for CO2. However, a better stability of the membrane at a higher temperature of 130 °C was desired. In this study, fluoride- and hydroxide-containing species, including tetramethylammonium fluoride (TMAF), cesium fluoride (CsF), potassium fluoride (KF), and N,N-dimethylpiperidinium hydroxide (DMPOH), were examined for their potential of replacing TMAOH to facilitate CO2 transport. The thermal stability of the quaternaryammonium-containing compounds was characterized by TGA and NMR, and the catalyzing activities of the fluoride-containing species were compared using NMR. Based on the characterization results, TMAF was chosen as the substitute for TMAOH, and the membrane synthesized with the optimal composition was tested for transport performances at various temperatures. In particular, a CO2 permeance of 108 GPU and a CO2/H2 selectivity of 106 were obtained at 120 °C. The TMAF-containing membrane also demonstrated an improved stability than the TMAOH-containing membrane at 130 °C.

Nanoporous Fluorinated Metal–Organic Framework-Based Membranes for CO2 Capture

The search for effective carbon-capture materials has permitted the disclosure and institution of nanoporous fluorinated metal–organic frameworks (MOFs) with a contracted pore system as benchmark CO2-selective adsorbents. Namely, the SIFSIX-3-M (M = Zn, Cu, and Ni) MOF adsorbents, encompassing a periodic arrangement of fluorine moieties in a confined one-dimensional channels, exhibit a remarkable CO2 adsorption-based selectivity over CH4 and H2 in various industrially related gas mixtures. Here, we report the successful transplantation/integration of this distinctive CO2 selectivity, distinguishing this class of nanoporous MOF adsorbents to pure MOF membranes for carbon capture. Markedly, the liquid-phase epitaxy (LPE) growth approach permitted, for the first time, the building of continuous, homogeneous, and defect-free MOF membranes based on the SIFSIX-3-M platform, MSiF6(Pyz)2 with M = Ni or Cu, on a porous alumina substrate. Single and mixed-gas permeation tests revealed that the resulting nanoporous MOF membrane is a CO2-selective membrane, exhibiting the foreseen favorable CO2-selectivity toward carbon dioxide over H2, and CH4, governed by the CO2-selective adsorption in the functional and contracted channels of the SIFSIX-3-M.

A Novel Process of H2/CO2 Membrane Separation of Shifted Syngas Coupled with Gasoil Hydrogenation

A novel process of membrane separation for H2/CO2 of shifted syngas coupled with gasoil hydrogenation (NMGH) is proposed. First, a new process, with two-stage CO2-selective and one-stage H2-selective membranes, was developed to substitute the conventional PSA separation devices to remove CO2 and purify H2 in coal gasification refineries to reduce energy consumption and investment costs. Then, the process was coupled with gasoil hydrogenation and the recycled H2 produced by the hydrogenation reactor could be further purified by the H2-selective membrane, which increased the H2 concentration of the hydrogenation reactor inlet by about 11 mol.% compared with the conventional direct recycling process, and the total system pressure was reduced by about 2470 kPa. At the same time, this additional membrane separation and purification prevented the accumulation of CO/CO2 in the recycled H2, which ensured the activity of the catalyst in the reactor and the long-term stable operation of the devices. Further, parameters such as compressor power, PI (polyimide)/PEO (polyethylene oxide) membrane area, pressure ratio on both sides of the membrane, and purity of make-up H2 were optimized by sensitivity analysis. The results showed that, compared with the conventional method, the NMGH process simplified operations, significantly reduced the total investment cost by $17.74 million, and lowered the total annual costs by $1.50 million/year.

Highly selective high-silica SSZ-13 zeolite membranes for H2 production from syngas

A highly CO2-selective high-silica SSZ-13 zeolite membrane was used for H2 production by separating CO2 from syngas (CO2/H2 mixture). High-silica SSZ-13 zeolite membranes were fabricated using outside asymmetric alumina tubes by secondary growth of ball-milled SSZ-13 seeds. The composition of membrane gel and synthesis time were modified. The Si/Al ratio in framework of the membrane was as high as 42 when SiO2/Al2O3 ratio of the gel increased to 140. The effects of test parameters such as pressure drop, temperature, feed flow rate and concentration on membrane performance were investigated. The test pressure drop was up to 2 MPa. The ultra-high CO2/H2 selectivity of 161 with excellent CO2 permeances of ~6.3 × 10−7 mol/(m2 s Pa) (=3760 GPU) were observed for the best membrane at 243 K and pressure drop of 0.2 MPa. Carbon dioxide permeance through high-silica SSZ-13 zeolite membrane was 4.2 × 10−7 mol/(m2 s Pa) (=2500 GPU) at 298 K and pressure drop of 2.0 MPa, and the CO2/H2 selectivity was 17.4. The current high-silica SSZ-13 zeolite membranes exceeded the upper bound of polymeric membranes and other inorganic membranes in CO2/H2 plots and owned great potentials for H2 production from syngas.

Hybrid membrane process for post-combustion CO2 capture from coal-fired power plant

Post-combustion CO2 capture is a promising way to reduce CO2 emissions at the coal-fired power plants. Even though several studies have been conducted regarding a wide variety of CO2 capture techniques, gas separation membrane process has shown potential as an energy-efficient, low-cost CO2 capture option. However, most of the previous researches focused only on CO2-selective membrane, and there's limited literature about the application of N2-selective membrane.In this study, both CO2-selective and N2-selective membranes are considered and relevant issues regarding the CO2-selective membrane, such as pressure ratio, attainability, and multistage configuration, are studied and extended to the N2-selective membrane. Polaris® membrane is served as a typical CO2-selective membrane; on the other hand, membrane properties of N2-selective membrane with selectivity up to 200 are considered. Hybrid membrane process applying both CO2- and N2-selective membranes for capturing at least 90% CO2 from a typical 550 MW subcritical coal-fired power plant is designed, simulated and analyzed using Aspen Plus® simulation software. The optimization and economic analysis are also applied with the cost factor defined in this work, which is a comprehensive index to evaluate the applicability of the membrane, including permeance, membrane lifetime and membrane price. The results reveal the relationship between the optimal design variables and membrane properties. Moreover, the selectivity-limited region is identified, which leads to two different dominant strategies for the cost reduction in a different region, either by the increase in selectivity or the reduction of the cost factor.

Influence of synthesis parameters on preparation of AlPO-18 membranes by single DIPEA for CO2/CH4 separation

CO2-selective AlPO-18 membranes were prepared hydrothermally on macroporous supports with a low-cost template N, N-diisopropylethylamine (DIPEA). The effects of synthesis parameters (such as gel dilution, synthesis temperature, synthesis time and aging time) on the structure, morphology and single gas permeation properties of CO2 and CH4 through AlPO-18 membranes were investigated in detail. The synthesis conditions had little effect on the membrane morphology but strongly affected the CO2/CH4 gas permeation properties of as-synthesized AlPO-18 membranes. The best membrane was obtained at a synthesis temperature of 433 K for 15 h after aging the precursor gel (1Al2O3: 1P2O5: 4DIPEA: 120H2O: 4IPA) for 24 h. The CO2 single gas permeance of this membrane was 1.1 × 10−6 mol/(m2 s Pa), with an ideal CO2/CH4 selectivity of 56 at 303 K and a 0.1 MPa pressure drop. The mixed gas CO2 permeance of same membrane with an equimolar CO2/CH4 mixture was 1.1 × 10−6 mol/(m2 s Pa) with a CO2/CH4 selectivity of 75 at 303 K and a 0.2 MPa pressure drop.

Top-Down Polyelectrolytes for Membrane-Based Post-Combustion CO2 Capture.

Polymer-based CO2 selective membranes offer an energy efficient method to separate CO2 from flue gas. ‘Top-down’ polyelectrolytes represent a particularly interesting class of polymer materials based on their vast synthetic flexibility, tuneable interaction with gas molecules, ease of processability into thin films, and commercial availability of precursors. Recent developments in their synthesis and processing are reviewed herein. The four main groups of post-synthetically modified polyelectrolytes discern ionised neutral polymers, cation and anion functionalised polymers, and methacrylate-derived polyelectrolytes. These polyelectrolytes differentiate according to the origin and chemical structure of the precursor polymer. Polyelectrolytes are mostly processed into thin-film composite (TFC) membranes using physical and chemical layer deposition techniques such as solvent-casting, Langmuir-Blodgett, Layer-by-Layer, and chemical grafting. While solvent-casting allows manufacturing commercially competitive TFC membranes, other methods should still mature to become cost-efficient for large-scale application. Many post-synthetically modified polyelectrolytes exhibit outstanding selectivity for CO2 and some overcome the Robeson plot for CO2/N2 separation. However, their CO2 permeance remain low with only grafted and solvent-casted films being able to approach the industrially relevant performance parameters. The development of polyelectrolyte-based membranes for CO2 separation should direct further efforts at promoting the CO2 transport rates while maintaining high selectivities with additional emphasis on environmentally sourced precursor polymers.

Permeation and sorption properties of CO2-selective blend membranes based on polyvinyl alcohol (PVA) and 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]) ionic liquid for effective CO2/H2 separation

This paper reports on the preparation and testing of blend membranes based on polyvinyl alcohol (PVA) and 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]) ionic liquid (IL) for effective CO2/H2 gas separation. Stable membranes with 9, 14, 24, 42 and 53 wt.% of IL were prepared via the solution casting procedure. Structural analysis (XRD, Raman, TGA and DSC) revealed that the increase of the incorporated IL content in PVA affected e.g. crystalline orientation in the diffraction plane 1 0 1 in favour of plane 2 0 0. The presence of the IL shifted the Tg (65 °C) and Tm (165 °C) of neat PVA to lower temperatures, towards the values of pure IL. The gas transport in neat PVA and PVA-IL blends with low IL content was found to be diffusivity-controlled, and the IL addition leads to an increase of both gas permeability and H2/CO2 selectivity. Instead, membranes with an IL content above 20 wt.% were more permeable for CO2 due to the prevailing solubility-controlled mechanism. Compared to neat PVA, which has barrier properties, the sample PVA-IL with 53 wt.% of IL exhibited an exceptional increase in gas permeability for both gases, H2circa 150 times to 8.65 Barrer and CO2 permeability circa 2400 times to 66.9 Barrer, with the corresponding ideal CO2/H2 selectivity of 7.73 that slightly exceeds the reverse CO2/H2 Robeson 2008 upper bound.

Techno-economic comparison of three technologies for pre-combustion CO2 capture from a lignite-fired IGCC

This paper compares the techno-economic performances of three technologies for CO2 capture from a lignite-based IGCC power plant located in the Czech Republic: (1) Physical absorption with a Rectisol-based process; (2) Polymeric CO2-selective membrane-based capture; (3) Low-temperature capture. The evaluations show that the IGCC plant with CO2 capture leads to costs of electricity between 91 and 120 € · MWh−1, depending on the capture technology employed, compared to 65 € · MWh−1 for the power plant without capture. This results in CO2 avoidance costs ranging from 42 to 84 € · $${\text{t}_{{\text{CO}_2},\text{avoided}}}^{ - 1}$$, mainly linked to the losses in net power output. From both energy and cost points of view, the low-temperature and Rectisol based CO2 capture processes are the most efficient capture technologies. Furthermore, partial CO2 capture appears as a good mean to ensure early implementation due to the limited increase in CO2 avoidance cost when considering partial capture. To go beyond the two specific CO2-selective membranes considered, a cost/membrane property map for CO2-selective membranes was developed. This map emphasise the need to develop high performance membrane to compete with solvent technology. Finally, the cost of the whole CCS chain was estimated at 54 € · $${\text{t}_{{\text{CO}_2},\text{avoided}}}^{ - 1}$$ once pipeline transport and storage are taken into consideration.

Non-ideal modelling of polymeric hollow-fibre membrane systems: Pre-combustion CO2 capture case study

Some membrane gas separation applications operate at high temperature and pressure. However, the majority of membrane gas separation models employ simplifying assumptions which are not realistic under these conditions. In this study, a rigorous model is developed for polymeric hollow-fibre membrane modules incorporating non-isothermal separation (the Joule-Thomson effect), real gas behavior and concentration polarization. The model also accounts for temperature-dependent permeability, friction-based pressure loss on both feed and permeate sides and variable physical and transport properties. The rigorous model is applied for pre-combustion CO2 capture, i.e. CO2/H2 separation, and compared with a simplistic model for various polymeric membranes through changing temperature-independent activation energy of permeation and pre-exponential factor. Two types of H2- and CO2-selective membranes are then chosen for further analysis. As feed conditions change, the deviation between the rigorous and simplistic models ranges approximately from 2 to 12% for stage-cut and 2–20% for the permeate composition. The difference is mostly because of real gas behavior at low stage-cuts, while the Joule-Thomson effect adds to this behavior at high stage-cuts (≥40%) resulting in the greater deviation. The influence of concentration polarization, however, is found negligible even at high stage-cuts.