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Development of membrane with improved carbon dioxide (CO 2 ) gas separation capability is a significant challenge. However, the fabrication of membrane that efficiently separate and purification CO 2 -containing gases has been the focus of global attention. Cellulose Acetate (CA) has robust reinforcing characteristics when incorporated within a suitable polymer matrix. This work focus on the synthesis of novel mixed matrix membranes (MMMs) by introducing Graphene-grafted bimetallic MOFs in Cellulose Acetate polymer. The graphene-grafted bimetallic MOF (GG-BM MOFs) was prepared by a hydrothermal technique. Whereas, the solution casting approach used to fabricate membranes. The 1-5 wt% of GG-BM MOFs incorporated into the CA matrix. The mechanical, hydrophilicity and adsorption characteristics of fabricated MMMs were investigated. The crystallinity of MMM enhanced after the addition of GG-BM MOFs. In addition, the mechanical characteristics of MMMs were improved with the incorporation of GG-BM MOFs inside the polymer matrix. Maximum stress and strain was obtained for 2 wt% MMM (36.4 N/mm 2 and 11% respectively). The CO 2 adsorption performance was evaluated at 10 bar and 45 °C. The FTIR results represent insignificant bond shifting with the addition GG-BM MOFs at these conditions. The overall results showed that MMMs containing 2 wt% GG-BM MOFs have good adsorption properties for CO 2 i.e 3.15 wt% of CO 2 . The MMMs have shown a decrease in the mechanical properties and CO 2 adsorption at the higher GG-BM MOFs loading due to the presence of agglomeration which was confirmed through SEM. Thus, the addition of GG-BM MOFs in the CA matrix positively altered the physicochemical characteristics of the resulting MMMs, which could assist them in achieving remarkable CO 2 adsorption at 2 wt%., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Mixed matrix membranes (MMMs) containing metal-organic frameworks (MOFs) have been an emerging and promising membrane technology to contribute to different gas separation applications including carbon dioxide (CO 2 ) and oxygen (O 2 ) separation, because of their large surface areas and distinctive gas adsorption features. In this work, the fabrication process of Polydimethylsiloxane (PDMS)-based MMMs was reported, in which 0.5 to 2 wt.% of each type of (Cu, Ni)-based MOF-74 variants were incorporated into a PDMS matrix in order to achieve high CO 2 /N 2 , O 2 /N 2 , and CO 2 /O 2 separation efficiency. These MMMs and their nanofillers (MOF-74) were extensively characterized using scanning electron microscopy (SEM) along with Energy Dispersive X-Ray (EDX) mapping, X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), a single gas permeation testing system, and an ultimate tensile strength testing (UTS) unit in order to gain insight into their properties in relation to their gas separation performance. The 1 wt.% of both (Cu and Ni)-MOF-74@PDMS were selected as the most optimum MMMs due to their uniform morphology and enhanced tensile strength, which exhibited high CO 2 permeabilities of 4432 Barrer (37.9% increase) and 4288 Barrer (33.5% increase), respectively. Furthermore, in the case of 1 wt.% Ni-MOF-74@PDMS, the CO 2 /N 2 , O 2 /N 2 , and CO 2 /O 2 selectivities were also enhanced to 36.2 (141.6% increase), 3.2 (21.9% increase), and 11.25 (98.1% increase), respectively. While, in the case of 1 wt.% Cu-MOF-74@PDMS the CO 2 /N 2 and O 2 /N 2 selectivities showed an increment up-to 94.7 (531.5% increase) and 6.47 (145% increase), respectively, Whereas, at 0.5 wt.%, Cu-MOF-74@PDMS showed the best CO 2 /O 2 selectivity of 25.26 (344.7% increase)., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Membrane-based gas separation has a great potential for reducing environmentally hazardous carbon dioxide (CO 2 ) gas. The polymeric membranes developed for CO 2 capturing have some limitations in their selectivity and permeability. There is a need to overcome these issues and developed such membranes having high-performance CO 2 capture with cost-effectiveness. The present study aimed to synthesize mixed matrix membranes (MMMs) having improved properties CO 2 adsorption performance and stability than that of pure polymer. Further, the effect on CO 2 adsorption by increasing the filler concentration in MMMs was investigated. The MMMs were synthesized by incorporating (1-5 wt%) Cu-MOF-GO composites as filler into cellulose-acetate (CA) polymer matrix by adopting the solution casting method. The performance of MMMs was studied by changing the Cu-MOF-GO composite concentration (1-5 wt%) in the polymer matrix at 45 °C up to 15 bar. Morphological analysis by using SEM confirms that by increasing the concentration of Cu-MOF-GO more than 3% will result in their agglomeration in MMM. The successful incorporation of MOF within the polymer matrix of MMMs was confirmed through the presence of functional groups using FTIR and Raman spectroscopy. XRD analysis revealed that pure CA changes its semi-crystalline behaviour into crystalline by the addition of Cu-MOF-GO. The maximum tensile stress and strain rate of MMMs was 45.1 N/mm 2 and 12.8%. In addition, with an increase in (4-5 wt%) Cu-MOF-GO concentration the hydrophilicity of MMMs decreases. The maximum uptake rate of CO 2 was 1.79 mmol/g and 7.98 wt% at 15 bar. The adsorption results conclude that Cu-MOF-GO composite and CA-based MMM can be effective for CO 2 capture., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The continuous carbon dioxide (CO2) gas emissions associated with fossil fuel production, valorization, and utilization are serious challenges to the global environment. Therefore, several developments of CO2 capture, separation, transportation, storage, and valorization have been explored. Consequently, we documented a comprehensive review of the most advanced strategies adopted in metal‐organic frameworks (MOFs) for CO2 capture and separation. The enhancements in CO2 capture and separation are generally achieved due to the chemistry of MOFs by controlling pore window, pore size, open‐metal sites, acidity, chemical doping, post or pre‐synthetic modifications. The chemistry of defects engineering, breathing in MOFs, functionalization in MOFs, hydrophobicity, and topology are the salient advanced strategies, recently reported in MOFs for CO2 capture and separation. Therefore, this review summarizes MOF materials′ advancement explaining different strategies and their role in the CO2 mitigations. The study also provided useful insights into key areas for further investigations. [ABSTRACT FROM AUTHOR]

• Synthesis of Ni-BDC MOF and its 1–8 wt% g-C 3 N 4 /Ni-BDC MOF composites were successfully prepared via the solvothermal method. • These samples are characterized by using different techniques like XRD, EDX, SEM, FTIR to investigate the structural and morphological properties. • The MOFs and their composites were studied for CO 2 adsorption and desorption at a temperature of 25 °C and 0–15 bar pressure. • 5 wt% g-C 3 N 4 /Ni-BDC MOF shows the highest adsorption capacity of 0.50 mmol/g. The substantial challenge that the world is facing nowadays, is the increase in greenhouse gasses which causes global warming. Therefore, there must be a technique to overcome its global emission rate. Accordingly, many absorbents and adsorption techniques are used to capture the CO 2 gas. Here, this study reports a novel class of adsorbents Metal Organic Framework (MOF) and its g-C 3 N 4 based composites are used to adsorb CO 2. The synthesis of Ni-BDC MOF and its 1–8 wt% g-C 3 N 4 /Ni-BDC MOF composites were successfully prepared via the solvothermal method. These samples are characterized by using different techniques like XRD, EDX, SEM, FTIR to investigate the structural and morphological properties. The MOFs and their composites were studied for CO 2 adsorption and desorption at a temperature of 25 °C and 0–15 bar pressure. Among all the composites, 5 wt% g-C 3 N 4 /Ni-BDC MOF shows the highest adsorption capacity of 0.50 mmol/g. The rising adsorption trend of all prepared materials shows that these samples do not reach their saturation point and can still adsorb more CO 2 even at pressure higher than 15 bar. [ABSTRACT FROM AUTHOR]

In this study Mn–DABDC (DABDC = diaminobenzenedicarboxylate, or 2,5-diaminoterephthalate) MOF was synthesised both via an electrochemical method, to make Mn–DABDC(ES), and via a conventional solvothermal approach, to make Mn–DABDC(ST). A Mn–BDC (BDC = benzenedicarboxylate) MOF was also prepared by a conventional solvothermal method for gas uptake capacity comparison. Investigation of the electrochemical synthesis parameters demonstrated that current density, electrolyte amount and reaction time were the most significant factors affecting crystal synthesis and product yield. The best conditions found for obtaining a crystalline MOF with high yield (93%) were 70 mA current, electrolyte 2.7 mmol/30 ml DMF and 2 h of reaction time. These optimized electrochemical conditions allow for a relatively fast MOF synthesis, important for reducing synthesis cost compared with conventional hydrothermal and solvothermal methods. The Mn–DABDC(ES) MOF sample was fully characterized to analyse its structure, thermal stability and surface area. The electrochemically synthesized MOF has high carbon dioxide uptake (92.4 wt% at 15 bar and 273 K) and hydrogen uptake (12.3 wt% at 80 bar and 77 K). This is the first amine-based manganese MOF synthesized electrochemically, and the method has excellent potential for reducing large-scale MOF production costs. [ABSTRACT FROM AUTHOR]

• Solvothermal synthesis and characterization of Cu-doped ZIF-8 catalysts with varying Cu+2 doping. • Electrochemical CO 2 reduction process. Cu30%ZIF-8 showed the highest current density of -40 mA cm−2 at -2.1 V vs. Ag/AgCl. • Better selectivity for CH 4 and CO compared to previous works on Cu electrodes. • High activity is due to crystalline nanostructure, sufficient Cu+2 metal sites, micro-meso dual-porosity nature and broad surface area. Electrochemical CO 2 reduction is a beneficial process for converting CO 2 into useful hydrocarbons, chemicals, and fuels. Many catalysts have been tested before for CO 2 electroreduction however achieving good stability, activity, and selectivity of the required product remains a challenge. In this work, we demonstrate the solvothermal synthesis and characterization of Cu-doped ZIF-8 catalysts with varying Cu+2 doping and applying them in the electrochemical CO 2 reduction process. Cu30%ZIF-8 showed the highest current density of -40 mA cm−2 at -2.1 V vs. Ag/AgCl and better selectivity for CH 4 and CO compared to previous works on Cu electrodes. This high activity of the Cu-doped ZIF-8 catalyst is because of the crystalline nanostructure of our catalyst with sufficient copper active metal sites and N-content, micro-meso dual-porosity nature of the structure, and broad surface area of zeolite imidazole framework to work on. [ABSTRACT FROM AUTHOR]

In this study, an artificial intelligence-based framework was developed to monitor the efficiency of the carbon capture unit, i.e., the Sour Compression Unit (SCU) and a cryogenic unit, in a cement manufacturing plant. Initially, an Aspen Plus-based model of the SCU and the cryogenic unit was developed. The process model was then transformed into dynamic mode through the interfacing of MATLAB and Excel with Aspen Plus to capture real-time process behavior. Five hundred fifty data samples were generated by varying the process conditions, i.e., inlet water flow rate, temperature, pressure, etc. The dataset was then used to develop ensemble models. Output compositions of the models were CO 2 , SO 2 , and NO. The ensemble models were used as surrogates in Sobol and Fourier Amplitude Sensitivity Test (FAST) frameworks to find the most sensitive process conditions that affect the efficiency of the process. The correlation coefficients based on the ensemble models for estimation of the composition of CO 2 , SO 2 , and NO, were 0.9888, 0.9663, and 0.9970, respectively. Based on the sensitivity analysis, the inlet flue gas temperature and pressure were the dominant variables that affect the mole fraction of SO 2 and NO in the flue gas. Besides, the CO 2 recovery was found heavily dependent on temperature of the flash tanks. The proposed framework was highly accurate and will provide a base for real-time implementation of the concept of smart factory in cement manufacturing plants. [ABSTRACT FROM AUTHOR]

Biogas up-gradation is a useful method to control CO 2 emission and enhance the green process. The demand for renewable sources is increasing due to the depletion of fossil fuels. Thin-film nanocomposites functionalized with tunable molecular-sieving nanomaterials have been employed to tailor membranes with enhanced permeability and selectivity. In this work, the cellulose nanocrystals as a filler in the polyvinyl alcohol matrix are prepared to achieve high-performance facilitated transport membranes for CO 2 capture. Considering the mechanical stability, interfacial compatibility and high moisture uptake of the filler, the main objective of this work was to develop a novel aminated CNC (Am-CNC)/polyvinyl alcohol nanocomposite membrane for biogas upgrading. The hydroxyl groups (O–H) on the reducing end of the cellulose nanocrystals were replaced by amino groups (N–H 2). It was discovered through Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) that adding Am-CNCs in PVA membranes shows an increment in the CO 2 removal and effectively upgrades the biogas. The effect of change in concentration of Am-CNC and feed pressure was investigated. The results showed that with increasing Am-CNC concentration up to 1.5 wt%, the thickness of the selective membrane layer increased from 0.95 to 1.9 μm with a decrease in the moisture uptake from 85.04 to 58.84%. However, the best CO 2 permeance and selectivity were achieved at 0.306 m3/m2.bar.h (STP) and 33.55, respectively. Furthermore, there was a more than two-fold decrease in CO 2 permeance and a 27% decrease in the CO 2 /CH 4 selectivity when the feed pressure increased from 5 to 15 bar. It was revealed that PVA/Am-CNC membrane is high performing for the biogas upgradation. • Development of PVA/Am-CNC membranes for biogas upgrading. • PVA/Am-CNC flat sheets were fabricated by using the dip coating method. • Moisture uptake was inversely proportional to Am-CNC concentration in membranes. • 1 wt% Am-CNC provides maximum CO 2 permeance 0.306 m3(STP)/m2.bar.hr. • CO 2 /CH 4 selectivity decreased 27% with an increase in feed pressure from 5 to 15 bar. [ABSTRACT FROM AUTHOR]