| 1. |
- Amjad, Um-e-Salma, et al.
(författare)
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Catalytic cracking of polystyrene pyrolysis oil: Effect of Nb2O5 and NiO/Nb2O5 catalyst on the liquid product composition
- 2022
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Ingår i: Waste Management. - : Elsevier. - 0956-053X .- 1879-2456. ; 141, s. 240-250
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Tidskriftsartikel (refereegranskat)abstract
- The catalytic cracking of polystyrene pyrolysis oil was investigated over a Nb2O5 and a NiO/Nb2O5 catalyst in a fixed bed reactor. First, the pyrolysis of two different polystyrene feedstock (polystyrene foam and polystyrene pellet) was carried out in a semi-batch reactor, and the resulting polystyrene pellets pyrolysis oil was selected for catalytic cracking reaction because of its high liquid yield (85%). Catalytic cracking experiments were then performed at different temperatures (350–500 °C) using Nb2O5 or NiO/Nb2O5 catalyst. Gas chromatography–mass spectrometry analysis of liquid product obtained from the catalytic cracking process showed that the dimers in the pyrolysis oil were converted to monomers during the catalytic cracking process. The catalytic cracking results also showed that the NiO/Nb2O5 catalyst (having slightly higher acidic sites) had slightly higher activity for monomer conversion than the Nb2O5 catalyst (having less acidic sites). X-ray diffraction, transmission electron microscopy, pyridine Fourier transform infrared spectroscopy, NH3 Temperature Programmed Desorption and X-ray photoelectron spectroscopy were used to characterize the catalyst. The highest catalytic cracking activity was observed at 400 °C with the Nb2O5 catalyst with 4% toluene, 6% ethylbenzene, approximately 50% styrene, 13% α-methyl styrene, and only 6% of dimers in the liquid oil. The increase in temperature positively affected the yield of gases during catalytic cracking process.
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| 2. |
- Azam, Kshaf, et al.
(författare)
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A review on activated carbon modifications for the treatment of wastewater containing anionic dyes
- 2022
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 306
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Forskningsöversikt (refereegranskat)abstract
- Polluted water resources, particularly those polluted with industrial effluents' dyes, are carcinogenic and hence pose a severe threat to sustainable and longstanding worldwide development. Meanwhile, adsorption is a promising process for polluted/wastewater treatment. In particular, activated carbon (AC) is popular among various wastewater treatment adsorbents, especially in the organic contaminants' remediation in wastewater. Hence, the AC's synthesis from degradable and non-degradable resources, the carbon activation involved in the AC synthesis, and the AC's modification to cutting-edge and effective materials have been modern-research targets in recent years. Likewise, the main research focuses worldwide have been the salient AC characteristics, such as its surface chemistry, porosity, and enhanced surface area. Notably, various modified-AC synthesis methods have been employed to enhance the AC's potential for improved contaminants-removal. Hence, we critically analyze the different modified ACs (with enhanced (surface) functional groups and textural properties) of their capacity to remove different-natured anionic dyes in wastewater. We also discuss the corresponding AC modification techniques, the factors affecting the AC properties, and the modifying agents' influence on the AC's morphological/adsorptive properties. Finally, the AC research of future interest has been proposed by identifying the current AC research gaps, especially related to the AC's application in wastewater treatment.
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| 3. |
- Naseer, Amtul, et al.
(författare)
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The robust catalysts (Ni1-x-Mo-x/doped ceria and Zn1-x-Mo-x/doped ceria, x=0.1 and 0.3) for efficient natural gas reforming in solid oxide fuel cells
- 2020
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 361
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Tidskriftsartikel (refereegranskat)abstract
- Nickel is a promising catalyst in Solid Oxide fuel cell (SOFC) due to its electrocatalytic performance, however, the practical utilization of Ni-based materials is hindered by the undesirable carbon deposition during methane decomposition. Herein, molybdenum is incorporated into the Ni- and Zn-based cermets (Ni1-x-Mo-x/GDC and Zn1-x-Mo-x/GDC, x = 0.1 and 0.3) to enhance electrocatalytic properties and avoid the carbon deposition during cell operation. The desired composites are synthesized by the impregnation method and adopted as anode in SOFCs. The catalytic activity for methane oxidation has been significantly improved due to the introduction on Mo, which hindered the carbon deposition due to higher graphitization and abundant active sites accessible to fuel. The detailed Raman spectroscopy and conductivity analysis revealed that addition of Mo reduced the amount of deposited carbon and enhanced the electrical conductivity. By using natural gas, as a fuel, the as-prepared Mo-doped Ni-GDC rendered a maximum power density of 690 mW cm(-2) at 600 degrees C. It is worth mentioning that the achieved stable power density is one of the best in existing literature. The current study presents a novel strategy to improve the catalytic behavior of electrode materials and demonstrate the optimal performance at low operating temperature. (C) 2020 Elsevier Ltd. All rights reserved.
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