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Incorporation of inorganic fillers into Polysulfone (PSF) to constitute mixed matrix membranes (MMMs) has become a viable solution to prevail over limitations of the pristine materials in natural gas sweetening process. Nevertheless, preparation of MMMs without defects and empirical investigation of membrane that exhibits characteristic of improved C[O.sub.2]/C[H.sub.4] separation performance at experimental scale are difficult that require prior knowledge on compatibility between the filler and polymer. A computational framework has been conducted to construct validated PSF based MMMs using silica (Si[O.sub.2]) as inorganic fillers. It is known that nanosized Si[O.sub.2] can coexist in varying polymorph configurations (ie, [alpha]-Quartz, [alpha]-Cristobalite, [alpha]-Tridymite) but molecular simulation study of Si[O.sub.2] polymorphs to form MMMs is limited. Therefore, this work is a pioneering study to elucidate feasibility in facile utilization of polymorphs to improve gas separation performance of MMMs. Physical properties and gas transport behavior of the simulated PSF based MMMs with different Si[O.sub.2] polymorphs and loadings have been elucidated. The optimal MMM has been found to be PSF/25 wt% [alpha]-Cristobalite at 55[degrees]C. The success in molecular simulation has shed light on how computational tools can provide understandings at molecular level to elucidate compatibility between varying pristine materials to MMMs for natural gas processing. KEYWORDS C[O.sub.2]/C[H.sub.4] separation, membrane, molecular simulation, polysulfone, [alpha]-Cristobalite, [alpha]-Quartz, [alpha]-Tridymite, 1 | INTRODUCTION Carbon dioxide (C[O.sub.2]) capture from natural gas is essential to comply with methane (C[H.sub.4]) product specification while simultaneously mitigating greenhouse gas environmental effect. [1] Glassy polymeric membrane [...]

Antireflective coating helps to reduce reflectance losses, thereby improving photovoltaic (PV) efficiency. Improving PV efficiency while maintaining low innovation cost has been a challenging task for the PV industry, especially in the case of monocrystalline silicon. Herein, the feasibility of integrating polydimethylsiloxane foil onto the protecting glass of an n‐type tunnel oxide–passivated contact silicon cell is studied. The foil is made using a polymer molding technique with digital video disk templates. On average, the foil provides 5.2% total reflectance and 93.5% total transmission. Under 1 sun illumination, the cell's power‐conversion efficiency increases by 12% (among the highest improvement), from 17.3% to 19.3%, in the presence of foil. A combined set of optical spectroscopy and simulation data shows that this improvement is due not only to the index‐matched medium, but also to forward scattering that increases broadband light transmission to the silicon cell through the foil which is different to the prevalent light‐trapping mechanism. The foil is also evaluated under different illumination conditions (indoors and outdoors), which show that the cell's power output nearly doubles at dimmer illumination levels and is stable under a fluctuating light source. While effective, the feasibility of antireflective foil should be reexamined further. [ABSTRACT FROM AUTHOR]

Waste tires have been identified as one of the contributors to environmental problems and the issue of inadequate landfill spaces. The lack of consistent and systematic approaches such as specific regulations/laws or mechanisms of waste management to waste tires, limited application of technology for recycling waste tires and lack of awareness on the impacts of waste tires problem, make waste tires a source of environmental pollution. Various researches have been conducted on recycling waste tires into polymer bends, and materials to harden concretes, fuels and adsorbent. Researchers suggested that pyrolysis is the current trend of recycling waste tire to harvest the saleable pyrolysis oil and the recycled carbon black. Therefore, this review attempts to compile relevant knowledge about the potential of adsorbent derived from waste tires to be applied in the removal of various types of pollutants like heavy metals, organic pollutants, dye and air/gaseous pollutant. Studies were carried out on revealing the properties and the characteristics of activated carbon derived from waste tire as effective adsorbent which influence the application performance at liquid or gas phase. In addition, the challenges in the production of activated carbon derived from waste tire were discussed. [ABSTRACT FROM AUTHOR]

Sequestration of CO2 is crucial to prevent further worsening of the environmental impact caused by global warming. Monoliths and membranes made from polymeric and inorganic materials have been used for CO2 removal to address environmental issues. Rapid prototyping technology offers a great potential for the fabrication of monoliths and membranes with high flexibility in terms of geometry and structure. This paper reviews the potential of the monolith and membrane fabricated through rapid prototyping for CO2 removal. The printing mechanism, chemical composition used in the fabrication of monoliths and membranes, as well as their CO2 removal capability are reviewed. The potential of monoliths and membranes is expected to be maximized for CO2 removal with the high flexibility in tailoring the geometry, surface area and associated with the fast growth of rapid prototyping technology. [ABSTRACT FROM AUTHOR]

BACKGROUND Natural gas is essential for the world's supply of energy due to its economic viability and environmental sustainability in producing adequate amounts of clean energy. However, the removal of CO2 as an undesirable impurity remains challenging in natural gas purification. In this work, high performance dense mixed matrix membranes (MMMs) containing a low loading (<2 wt%) of zeolitic imidazolate framework 8 (ZIF‐8) and polysulfone (PSF) were prepared via simple solvent evaporation method and single solvent for the removal of CO2 from CH4. RESULTS: Significant enhancements in CO2 permeability and CO2/CH4 ideal selectivity were obtained for the resultant MMMs as compared to the neat PSF membrane. The highest CO2 permeability of 33.57 Barrer and CO2/CH4 ideal selectivity of 39.03 were achieved for a PSF membrane loaded with 1 wt% of ZIF‐8; these values were 514% and 161% higher than those obtained for the neat PSF membrane, respectively. Furthermore, MMM embedded with 1 wt% of ZIF‐8 demonstrated CO2 plasticization pressure up to 16 bar, which is equivalent to an 100% increment of the value obtained for the neat PSF membrane. CONCLUSION: Overall, MMMs fabricated in this work demonstrated a significant improvement of CO2 separation from CH4 compared to the PSF‐based MMMs reported in the literature, where most of the reported MMMs contain high loading of fillers up to 30 wt%. Therefore, the MMMs fabricated in this work are ready to be further exploited for application in gas separation industries. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Composite membranes comprising NH2-MIL-125(Ti)/PEBAX coated on PDMS/PSf were prepared in this work, and their gas separation performance for high CO2 feed gas was investigated under various operating circumstances, such as pressure and CO2 concentration, in mixed gas conditions. The functional groups and morphology of the prepared membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). CO2 concentration and feed gas pressure were demonstrated to have a considerable impact on the CO2 and CH4 permeance, as well as the CO2/CH4 mixed gas selectivity of the resultant membrane. As CO2 concentration was raised from 14.5 vol % to 70 vol %, a trade-off between permeance and selectivity was found, as CO2 permeance increased by 136% and CO2/CH4 selectivity reduced by 42.17%. The membrane produced in this work exhibited pressure durability up to 9 bar and adequate gas separation performance at feed gas conditions consisting of high CO2 content. [ABSTRACT FROM AUTHOR]

The challenges in developing high CO2 gas fields are governed by several factors such as reservoir condition, feed gas composition, operational pressure and temperature, and selection of appropriate technologies for bulk CO2 separation. Thus, in this work, we report an optimization study on the separation of CO2 from CH4 at high CO2 feed concentration over a functionalized mixed matrix membrane using a statistical tool, response surface methodology (RSM) statistical coupled with central composite design (CCD). The functionalized mixed matrix membrane containing NH2-MIL-125 (Ti) and 6FDA-durene, fabricated in our previous study, was used to perform the separation performance under three operational parameters, namely, feed pressure, temperature, and CO2 feed concentration, ranging from 3.5–12.5 bar, 30.0–50.0 °C and 15–70 mol%, respectively. The CO2 permeability and CO2/CH4 separation factor obtained from the experimental work were varied from 293.2–794.4 Barrer and 5.3–13.0, respectively. In addition, the optimum operational parameters were found at a feed pressure of 12.5 bar, a temperature of 34.7 °C, and a CO2 feed concentration of 70 mol%, which yielded the highest CO2 permeability of 609.3 Barrer and a CO2/CH4 separation factor of 11.6. The average errors between the experimental data and data predicted by the model for CO2 permeability and CO2/CH4 separation factor were 5.1% and 3.3%, respectively, confirming the validity of the proposed model. Overall, the findings of this work provide insights into the future utilization of NH2-MIL-125 (Ti)/6FDA-based mixed matrix membranes in real natural gas purification applications. [ABSTRACT FROM AUTHOR]