| 1. |
- Thomas, HS, et al.
(författare)
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- 2019
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swepub:Mat__t
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| 2. |
- Abd Mutalib, Nor Fariza, et al.
(författare)
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A Prediction for the Conversion Performance of H2S to Elemental Sulfur in an Ionic-Liquid-Incorporated Transition Metal Using COSMO-RS
- 2022
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Ingår i: CHEMISTRY-SWITZERLAND. - : MDPI AG. - 2624-8549. ; 4:3, s. 811-826
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the conversion performance of hydrogen sulfide (H2S) to elemental sulfur in ionic-liquid-incorporated transition metals (ILTMs) is predicted using a conductor-like screening model for realistic solvents (COSMO-RS). The predictions were made via the establishment of a correlation between the conversion performance and solubility of H2S in ionic liquids (ILs). All molecules involved were optimized at the DFT/TZVP/M06 computational level and imported on the COSMOtherm program at equimolar conditions. For validation purposes, the solubility of ILs was predicted at 1 bar pressure. Simple regression analysis was used to establish a relationship between the solubility and conversion performance of H2S. The results indicate that the solubility prediction of ILs is accurate (R-2 = 93.40%) with a p-value of 0.0000000777. Additionally, the conversion performance is generally found to be dependent on the solubility value. Furthermore, 1-butyl-3-methylimidazolium chloride [bmim][Cl] was chosen as the base IL for incorporating the transition metal, owing to its solubility and selectivity to H2S. The solubility trend of ILTMs is found to follow the following order: [bmim][NiCl3] > [bmim][FeCl4] > [bmim][CoCl3] > [bmim][CuCl3]. According to the viscosity measurements of ILTMs, [bmim][NiCl3] and [bmim][FeCl4] exhibited the highest and lowest viscosity values, respectively. Therefore, [bmim][FeCl4] is a promising ILTM owing to its higher solubility and low viscosity for the application studied.
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| 3. |
- Ahmad, Tausif, et al.
(författare)
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Controllable phytosynthesis of gold nanoparticles and investigation of their size and morphology-dependent photocatalytic activity under visible light
- 2020
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Ingår i: Journal of Photochemistry and Photobiology A. - : Elsevier. - 1010-6030 .- 1873-2666. ; 392, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Plants mediated synthesis of gold nanoparticles (AuNPs) containing desired characteristics for their suitable potential applications has been a challenging task, which is causing a major hindrance towards its commercialization. Therefore, herein phytosynthesis of AuNPs with required size and morphology has been achieved through manipulating the reaction conditions including reaction temperature and volume of Elaeis guineensis leaves (EGL) extract. Furthermore, photocatalytic potential of EGL mediated AuNPs having different size and shape has also been explored for the removal of methylene blue (MB) under visible light irradiation. The reaction temperature and volume of EGL strongly influenced the size and morphology of AuNPs, which are directly associated with the photocatalytic activities. The experimental results revealed that predominantly spherical and ultra-smaller size AuNPs with particle size of 16.26 ± 5.84 nm, formed at 70 °C showed the highest removal efficiency up to 92.55 % in 60 min. This highest photocatalytic activity of AuNPs could be attributed to the availability of higher number of low-coordinated gold (Au) atoms in the MB aqueous solution, which might have boosted the adsorption of the MB on the surface of particles and accelerated the degradation phenomenon. The proposed photocatalytic degradation mechanism of AuNPs for MB was also explained. The highly photoactive EGL mediated AuNPs with controllable morphology and size could be an advance step in future in chemical and biomedical applications.
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| 4. |
- Awad, A., et al.
(författare)
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Catalytic decomposition of 2% methanol in methane over metallic catalyst by fixed-bed catalytic reactor
- 2021
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Ingår i: Energies. - : MDPI. - 1996-1073. ; 14:8
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Tidskriftsartikel (refereegranskat)abstract
- The structure and performance of promoted Ni/Al2O3 with Cu via thermocatalytic decomposition (TCD) of CH4 mixture (2% CH3OH) were studied. Mesoporous Cat-1 and Cat-2 were synthesized by the impregnation method. The corresponding peaks of nickel oxide and copper oxide in the XRD showed the presence of nickel and copper oxides as a mixed alloy in the calcined catalyst. Temperature program reduction (TPR) showed that Cu enhanced the reducibility of the catalyst as the peak of nickel oxide shifted toward a lower temperature due to the interaction strength of the metal particles and support. The impregnation of 10% Cu on Cat-1 drastically improved the catalytic performance and exhibited 68% CH4 conversion, and endured its activity for 6 h compared with Cat-1, which deactivated after 4 h. The investigation of the spent carbon showed that various forms of carbon were obtained as a by-product of TCD, including graphene fiber (GF), carbon nanofiber (CNF), and multi-wall carbon nanofibers (MWCNFs) on the active sites of Cat-2 and Cat-1, following various kinds of growth mechanisms. The presence of the D and G bands in the Raman spectroscopy confirmed the mixture of amorphous and crystalline morphology of the deposited carbon.
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| 5. |
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| 6. |
- Ellaf, A., et al.
(författare)
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Energy, exergy, economic, environment, exergo-environment based assessment of amine-based hybrid solvents for natural gas sweetening
- 2023
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 313
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Tidskriftsartikel (refereegranskat)abstract
- Natural gas is the cleanest form of fossil fuel that needs to be purified from CO2 and H2S to diminish harmful emissions and provide feasible processing. The conventional chemical and physical solvents used for this purpose have many drawbacks, including corrosion, solvent loss, high energy requirement, and the formation of toxic compounds, which ultimately disrupt the process and affect the environment. Hybrid solvents have lately been researched to cater to these liabilities and enhance process economics. This study screened eight solvents based on CO2 selectivity viscosity, absorption enthalpy, corrosivity, working capacity, specific heat, and vapor pressure. From the screened solvents, ten cases of hybrid solvents are simulated and optimized on Aspen HYSYS®. Furthermore, 5Es (Energy, Exergy, Economic, Environmental, and Exergy-environmental) analyses were performed on optimized cases, and results were compared with the base case, MEA (30 wt%). The hybrid blend of Sulfolane and MDEA with weight percentages of 6% and 24%, respectively, showed the highest energy savings of 20% concerning the base case. In addition, it offered 93% savings in exergy destruction and 17.26% in the total operating cost of the process. It is also promising to the environment due to reduced entropy sent to the ecosystem and controlled CO2 emissions. Therefore, the blend of Sulfolane and MDEA is proposed to Supersede the conventional solvent MEA for the natural gas sweetening process.
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| 7. |
- Gozali, Ebrahim, et al.
(författare)
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Numerical Modeling of a Short-Dwell Coater for Bio-Based Coating ApplicationsCoatings
- 2020
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Ingår i: Coatings. - : MDPI. - 2079-6412. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Computational fluid dynamics (CFD) simulations were used for the evaluation of critical issues associated with coating processes with the aim of developing and optimizing this important industrial technology. Four different models, namely, the constant viscosity, shear thinning, Oldroyd-B viscoelastic, and Giesekus models, were analyzed and compared in a short-dwell coater (SDC) using a bio-based coating material. The simulation results showed that the primary vortex formations predicted by the viscoelastic models were highly dependent on the flow Deborah number, resulting in uneven stress distribution over the coated surface. For the viscoelastic models, the dominance of elastic forces over viscous forces gave rise to significant normal stress difference, primarily along the surface of the substrate paper. The shear-thinning phenomena predicted by the Giesekus model, however, tended to relax the stress development in contrast to the Oldroyd-B model. The observations indicate that a reduced coating velocity or modification of the coating material with a reduced relaxation time constant can significantly enhance the uniformity and thickness of the coating over the coated surface under controlled conditions.
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| 8. |
- Hamzah, Wan Suzaini Wan, et al.
(författare)
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Microwave-assisted chemistry : parametric optimization for catalytic degradation of lignin model compounds in imidazolium-based ILs
- 2021
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Ingår i: Biomass Conversion and Biorefinery. - : Springer Berlin/Heidelberg. - 2190-6815 .- 2190-6823.
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Tidskriftsartikel (refereegranskat)abstract
- Lignin, a readily available form of biomass with a potential source of aromatic chemical compounds, has not been fully utilized due to its complex structure. Hence, this study aims to elaborate and optimize the effects of parametric microwave conditions for the catalytic degradation of lignin model compounds. In addition to that, 41 types of imidazolium-based Ionic liquids were employed for the conversion of lignin model compounds such as guaiacol and benzyl phenyl ether. The microwave-assisted conversion of lignin model compounds in imidazolium-based ionic liquids was performed at optimum applied microwave power 700 W and 30-min irradiation time. The percentages conversion and yield were quantified using high-performance liquid chromatography (HPLC) analysis. Results revealed that the chloride anion-based ionic liquids exhibited better nucleophilic behavior and catalyzed the cleavage of ether-based compounds efficiently under microwave irradiation. Among the imidazolium-based ionic liquids, 1H-methylimidazolium chloride ([1H-MIM][Cl]) exhibited better performance with guaiacol conversion and catechol yield of 99% and 81%, respectively. Therefore, the microwave-assisted technique was found to be more promising than conventional methods for the ionic liquid-based catalytic degradation of lignin model compounds.
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| 9. |
- Hussain, M., et al.
(författare)
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Optimization of lithium adsorption from seawater via aluminum chloride as adsorbent using response surface methodology
- 2024
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Ingår i: Energy Sources, Part A. - : Informa UK Limited. - 1556-7036 .- 1556-7230. ; 46:1, s. 2907-2921
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Tidskriftsartikel (refereegranskat)abstract
- Lithium extraction from natural resources is an accelerating field of research owing to its growing demand in the medical, nuclear, battery, and air conditioning industries. Lithium compounds are used in various industries, including ceramics, glass, lubricant gases, rocket propellant, and aluminum production. The extraction of lithium from seawater via adsorption using AlCl3.6 H2O as an adsorbent is investigated in this study. The effect of process parameters such as pH, temperature, contact time, the molar ratio ([Al3+]/[Li+]), and stirring rate on process efficiency is investigated and optimized. The response surface methodology (RSM) is used to investigate the effects of operating parameters and choose the optimal configuration. A standard synthetic solution containing 50 ppm lithium is prepared and experimented with facilitating comprehension of the procedure. The adsorption efficiency of a synthetic solution is 88% at optimized values, while that of seawater is 78.5%. Seawater has a lower efficiency because it contains ions such as Mg2+, Ca2+, K+, and Na+ that compete for active points/sites during adsorption with lithium ions (Li+).
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| 10. |
- Idris, Alamin, et al.
(författare)
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A review on predictive tortuosity models for composite films in gas barrier applications
- 2022
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Ingår i: JCT Research. - : Springer. - 1547-0091 .- 2168-8028. ; 19, s. 699-716
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Tidskriftsartikel (refereegranskat)abstract
- Different types of impermeable fillers are usually incorporated into polymeric coating film to enhance the gas barrier properties. For instance, impermeable fillers are commonly used in barrier coating due to their larger surface, which in turn serve as barrier inclusions restricting the penetrant gas to diffuse through a longer tortuous pathway. Modeling gas transport in barrier coating can help determine the shelf-life of packaged food and reduce product development resources and time. In this paper, related tortuosity-based models corresponding to different filler geometries are outlined. This review emphasizes the emerging trends in modeling the tortuous pathway and the respective relative permeability model to predict the gas barrier performance in composite films used for barrier coating applications. We review models incorporating a range of factors, including different shapes, geometries, angular orientations, alignments, randomness in distribution, stacking, interspacing, and the polydispersity of fillers. The approaches employed to develop the tortuosity-based phenomenological models starting with simplified filler geometry and orientations to more complex morphological features of the composite films are elaborated.
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