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Among several known zeolites, silicoaluminophosphate (SAPO)‐34 zeolite exhibits a distinct chemical structure, unique pore size distribution, and chemical, thermal, and ion exchange capabilities, which have recently attracted considerable research attention. Global carbon dioxide (CO2) emissions are a serious environmental issue. Current atmospheric CO2 level exceeds 414 parts per million (ppm), which greatly influences humans, fauna, flora, and the ecosystem as a whole. Zeolites play a vital role in CO2 removal, recycling, and utilization. This review summarizes the properties of the SAPO‐34 zeolite and its role in CO2 capture and separation from air and natural gas. In addition, due to their high thermal stability and catalytic nature, CO2 conversions into valuable products over single metal, bi‐metallic, and tri‐metallic catalysts and their oxides supported on SAPO‐34 were also summarized. Considering these accomplishments, substantial problems related to SAPO‐34 are discussed, and future recommendations are offered in detail to predict how SAPO‐34 could be employed for greenhouse gas mitigation. [ABSTRACT FROM AUTHOR]

Betaine-based natural deep eutectic solvents (NADESs), a new class of green solvents, were immobilized into a porous polyvinylidene fluoride (PVDF) support and evaluated for the separation of CO2 from CO2/N2 and CO2/CH4 mixtures. Two types of NADESs were synthesized by mixing betaine (hydrogen bond acceptor-HBA) with malic acid and tartaric acid (hydrogen bond donors-HBD) respectively. FTIR and Raman spectroscopy were studied to confirm the synthesis and purity of the NADESs. The thermal strength of the NADESs was investigated using thermogravimetric analysis. The gas permeation results of the fabricated NADES-based-supported liquid membranes (NADES-SLMs) showed that the permeability of CO2 increased from 25.55 to 29.33 Barrer on substitution of hydrogen bond donor from tartaric acid to malic acid. Similarly, the ideal CO2/CH4 selectivity varied from 51.1 to 56.4 as tartaric acid was replaced by malic acid as the HBD. The performance of NADES-SLMs was compared with the competing imidazolium-based-supported ionic liquid membranes, and proved NADES-SLMs as a promising alternative considering their green potential and comparable gas separation performance. The current effort for the exploitation of NADESs into PVDF membranes in this study is expected to open new routes for the efficient separation of CO2 from the industrial gas mixture. [ABSTRACT FROM AUTHOR]

CO2 emission from anthropogenic sources has raised worldwide environmental concerns and hence proficient energy paradigm has tilted towards CO2 capture. Membrane technology is one of the efficient technologies for CO2 separation since it is environmentally friendly, inexpensive, and offers high surface areas. Various approaches are discussed to improve membrane performance focusing mainly on permeability and selectivity parameters. Different types of fillers are incorporated to reach the Robeson's upper bound curve. In this review, polymer‐inorganic nanocomposite membranes for the separation of CO2, CH4, and N2 from various gas mixtures are comprehensively discussed. Metal organic frameworks (MOFs) and ionic liquid (ILs) mixed‐matrix membranes are also considered. Membrane technology is considered as an efficient, environmentally friendly, and inexpensive technology for CO2 separation. Various approaches to improve membrane performance are reviewed with the focus on permeability and selectivity parameters. Polymer‐inorganic nanocomposite membranes, metal organic frameworks, and ionic liquid mixed‐matrix membranes are also discussed and evaluated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of highly selective Choline Chloride based Deep Eutectic Solvent. • High CO 2 permeability for a supported DES based liquid membrane. • Supported liquid membranes showed excellent stability under different operating conditions. This study focuses on a forward looking approach in which deep eutectic solvents (DESs), a new class of designer solvents, were impregnated into micro porous polyvinylidene fluoride (PVDF) membrane for the separation of CO 2 from CH 4. Three types of DESs were prepared by mixing and heating of hydrogen bond acceptor (choline chloride) with either malic acid, tartaric acid or oxalic acid as hydrogen bond donor. The Fourier transform infrared spectroscopy confirmed the hydrogen bond interactions in the resulting DES. Thermal gravimetric analysis (TGA) was used to evaluate the thermal stability of the prepared membranes. The DES based supported liquid membranes were investigated systematically to determine the permeability and selectivity for the mixture of gases at both ambient and elevated temperatures. The results showed that Choline Chloride-Malic acid, Choline Chloride-Tartaric acid and Choline Chloride-Oxalic acid DES-SLMs exhibited CO 2 permeability of 30.32 Barrer, 34.00 Barrer and 37.30 Barrer, respectively while ideal selectivity of these membranes was found 51.39, 55.74 and 60.16 for CO 2 /CH 4 , respectively. The fabricated membranes were compared with some of the imidazolium supported ionic liquid membranes (SILMs) on the Robeson upper bound plot. The current study on DES-SLMs is expected to open new pathways for the exploitation of DESs for CO 2 capture. [ABSTRACT FROM AUTHOR]

This study focuses on the effect of modified silica fillers by [EMIN][Tf2N] via physical adsorption on the CO2 separation performance of a mixed matrix membrane (MMM). The IL-modified silica was successfully synthesized as the presence of fluorine element was observed in both Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectrometer (XPS) analyses. The prepared MMMs with different loadings of the IL-modified silica were then compared with an unmodified silica counterpart and neat membrane. The morphology of IL-modified MMMs was observed to have insignificant changes, while polymer chains of were found to be slightly more flexible compared to their counterpart. At 2 bar of operating pressure, a significant increase in performance was observed with the incorporation of 3 wt% Sil-IL fillers compared to that of pure polycarbonate (PC). The permeability increased from 353 to 1151 Barrer while the CO2/CH4 selectivity increased from 20 to 76. The aforementioned increment also exceeded the Robeson upper bound. This indicates that the incorporation of fillers surface-modified with ionic liquid in an organic membrane is worth exploring for CO2 separation. [ABSTRACT FROM AUTHOR]

A combination of organic filler exhibiting CO 2 philic nature with a polymer to develop mixed matrix membranes (MMMs) can capture CO 2 efficiently. This work reports the synthesis of perylene filler and polysulfone (PSf)-based MMMs via solution casting method. The successful incorporation of fillers, uniformity/asymmetric, and amorphous nature of MMMs were investigated by FT-IR, FESEM, and PXRD analysis, respectively. MMMs demonstrated high thermal stability with significant weight retention over 750 °C investigated by TGA analysis. The existence of Lewis's basic functionalities, hydrogen bonding, and π-π bonds between the filler-polymer resulted in the formation of highly CO 2 philic structure. Results revealed that the perylene is found to be highly porous (1050 m2/g) and compatible with the PSf to form additional channels, enhancement of free PSf volume and tendency to prevent the agglomeration and non-selective interfacial voids. It demonstrated improved permeabilities of CO 2 (138%), CH 4 (59%), and N 2 (60%) without any significant variation in selectivities CO 2 /CH 4 (3%) and CO 2 /CH 4 (7%). Similarly, mixed gas permeabilities were improved for (CO 2 –CH 4 – 119%) and (CO 2 –N 2 – 116%) along with enhanced selectivities (CO 2 –CH 4 – 50%) and (CO 2 –N 2 – 46%). Furthermore, the influence of temperature on gas permeabilities revealed improved kinetic energy and flexibility in the polymer chains. The mechanical strength analysis revealed high filler-polymer compatibility. These results revealed great potential of MMMs for efficient CO 2 separation from pre- and post-combustion sources. • Organic perylene filler incorporated PSf MMMs were synthesized and characterized. • Synthesized Membranes demonstrated high mechanical strength. • Pure and binary gas permeation behavior for CO 2 /CH 4 and CO 2 /N 2 was investigated. • Temperature influence on permeabilities revealed improved kinetic energies. [ABSTRACT FROM AUTHOR]

• Modification of ZIF-67 with highly selective 3-(trimethoxysilyl)propan-1-aminium acetate. • Simultaneous increase in CO 2 /CH 4 and CO 2 /N 2 selectivity and CO 2 permeability. • Enhanced CO 2 solubility owing to the molecular sieving of ZIF-67 and CO 2 selective properties of RTIL. Mixed matrix membranes (MMMs) have shown remarkable progress in the development of high-performance membranes for gas separation. These membranes combine the advantageous properties of both organic polymers and highly selective inorganic fillers. Developments are in process for synthesis and modification of fillers to promote the separation performance. Ionic liquids (ILs) are an emerging class of solvents having high CO 2 solubility. In this study, amine based RTIL 3-(trimethoxysilyl) propan-1-aminium acetate [APTMS][Ac] was synthesized. Zeolitic imidazolate framework, ZIF-67, was used as inorganic filler due to its shape selective property and appropriate pore size. ZIF-67 was modified by incorporation of RTIL, and subsequently MMMs with Polysulfone (PSf) matrix were prepared. Gas separation data showed that RTIL having –NH 2 group as well as acetate ions combined with ZIF-67 nano porous structure and large surface area improved the separation performance of membranes. Increase in selectivity of three component MMMs by 84% and 90% was observed ranging from 39.02 to 72.06 and 39 to 74.47 for CO 2 /CH 4 and CO 2 /N 2 respectively in compared with PSf-RTIL blend membranes. RTIL provided facilitation role in gas permeations due to its high CO 2 selective nature. [ABSTRACT FROM AUTHOR]

In this study, a facile and extensible one pot approach was utilized to synthesize ionic liquid inside a porous metal organic framework (UiO-66). Different characterization techniques were used to confirm the successful synthesis of UiO-66@IL composite. The MMMs were characterized and tested for CO 2 separation from CH 4 or N 2 at ambient and elevated temperatures. SEM images exhibited well dispersion of the filler particles with no notable defect even at high loadings. Single and mixed gas permeation results indicated significant performance (CO 2 permeability: 143 Barrer and CO 2 /CH 4 , CO 2 /N 2 selectivity: 28.32, 61.11 respectively) by enhancing the permeability of CO 2 by 74% and selectivity to 31% and 26% for CO 2 /CH 4 and CO 2 /N 2 compared with neat Pebax®1657 membrane. [Display omitted] • Ship in bottle technique was used to synthesize UiO-66@IL composite. • XRD, SEM, and FTIR confirmed the successful synthesis of UiO-66@IL composite. • MMM were fabricated with UiO-66@IL composite and Pebax®1657. • Simultaneously high CO 2 permeability and CO 2 /CH 4 , CO 2 /N 2 selectivity were achieved. [ABSTRACT FROM AUTHOR]