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- Lebedeva, Daria, 1994-, et al.
(author)
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Synthesis of Cyclobutane-Based Sustainable Aviation Fuel from Prehydrolysis Liquors
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Other publication (other academic/artistic)abstract
- Maximizing products of high value and minimizing incineration of side-streams is key to realize future biorefineries. In current textile production from forestry, hemicellulose is removed by prehydrolysis before delignification. The resulting prehydrolysis liquor is incinerated in the recovery boiler at low efficiency. This additional burden on the limiting recovery boiler reduces the pulp production. In this study, we demonstrate that prehydrolysis liquor can be upgraded, in 5 steps, to yield aviation fuels. Prehydrolysis liquors were dehydrated to furfural by zeolite catalysis. Furfural was selecitvely reduced to furfuryl alcohol by homogeneous catalysis. Rhenium-catalyzed Achmatowicz rearrangement gave a C5 intermediate susceptable to self [2+2] cycloaddition to give the C10 oxygenated precursor. By using a combination of Ru/C and zeolites, full hydrodeoxygenation was achieved. The resulting hydrocarbons, containing a strained four-membered ring, are preferred aviation fuel components. This is an important step to show that aviation fuels can be produced sustainably from existing industrial side-streams.
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- Piątek, Jędrzej, et al.
(author)
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Toward Sustainable Li-Ion Battery Recycling : Green Metal-Organic Framework as a Molecular Sieve for the Selective Separation of Cobalt and Nickel
- 2021
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In: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 9:29, s. 9770-9778
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Journal article (peer-reviewed)abstract
- The growing demand for Li-ion batteries (LIBs) has made their postconsumer recycling an imperative need toward the recovery of valuable metals, such as cobalt and nickel. Nevertheless, their recovery and separation from active cathode materials in LIBs, via an efficient and environmentally friendly process, have remained a challenge. In this work, we approach a simple and green method for the selective separation of nickel ions from mixed cobalt-nickel aqueous solutions under mild conditions. We discovered that the bioinspired microporous metal-organic framework (MOF) SU-101 is a selective sorbent toward Ni2+ ions at pH 5-7 but does not adsorb Co2+ ions. According to the Freundlich isotherm, the adsorption capacity toward Ni2+ reached 100.9 mg.g(-1), while a near-zero adsorption capacity was found for Co2+ ions. Ni2+ removal from aqueous solutions was performed under mild conditions (22 degrees C and pH 5), with a high yield up to 96%. The presence of Ni2+ ions adsorbed on the surface of the material has been proven by solid-state H-1 nuclear magnetic resonance spectroscopy. Finally, the separation of Ni2+ from Co2+ from binary solutions was obtained with approximately 30% yield for Ni2+, with a near-zero adsorption of Co2+, which has been demonstrated by UV-vis spectroscopy. The ion adsorption process of Ni2+ and Co2+ ions was additionally studied by means of classical molecular dynamics calculations (force fields), which showed that the Ni2+ ions were more prone to enter the MOF canals by replacing some of their coordinated water molecules. These results offer a green pathway toward the recycling and separation of valuable metals from cobalt-containing LIBs while providing a sustainable route for waste valorization in a circular economy.
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- Cui, Peng, et al.
(author)
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An Expandable Hydrogen-Bonded Organic Framework Characterized by Three-Dimensional Electron Diffraction
- 2020
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In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 142:29, s. 12743-12750
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Journal article (peer-reviewed)abstract
- A molecular crystal of a 2-D hydrogen-bonded organic framework (HOF) undergoes an unusual structural transformation after solvent removal from the crystal pores during activation. The conformationally flexible host molecule, ABTPA, adapts its molecular conformation during activation to initiate a framework expansion. The microcrystalline activated phase was characterized by three-dimensional electron diffraction (3D ED), which revealed that ABTPA uses out-of-plane anthracene units as adaptive structural anchors. These units change orientation to generate an expanded, lower density framework material in the activated structure. The porous HOF, ABTPA-2, has robust dynamic porosity (SA(BET) = 1 183 m(2) g(-1)) and exhibits negative area thermal expansion. We use crystal structure prediction (CSP) to understand the underlying energetics behind the structural transformation and discuss the challenges facing CSP for such flexible molecules.
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- Elter, Zsolt, et al.
(author)
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Development of a modeling approach to estimate radiation from a spent fuel rod quiver
- 2020
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In: PHYSOR 2020. - : EDP Sciences. - 9781527264472
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Conference paper (peer-reviewed)abstract
- Before encapsulation of spent nuclear fuel in a geological repository, the fuels need to be verified for safeguards purposes. This requirement applies to all spent fuel assemblies, including those with properties or designs that are especially challenging to verify. One such example are quivers, a new type of containers used to hold damaged spent fuel rods. After placing damaged rods inside the quivers, they are sealed with a thick lid and the water is removed. The lid is thick enough to significantly reduce the amount of the gamma radiation penetrating through it, which can make safeguards verification from the top using gamma techniques difficult. Considering that the number of quivers at storage facilities is foreseen to increase in near future, studying the feasibility of verification is timely.In this paper we make a feasibility study related to safeguards verification of quivers, aimed at investigating the gamma and neutron radiation field around a quiver designed by Westinghouse AB and filled with PWR fuel rods irradiated at the Swedish Ringhals site. A simplified geometry of the quiver and the detailed operational history of each rod are provided by Westinghouse and the reactor operator, respectively.The nuclide inventory of the rods placed in the quiver and the emission source terms are calculated with ORIGEN-ARP. The radiation transport is modeled with the Serpent2 Monte Carlo code. The first objective is to assess the capability of the spent fuel attribute tester (SFAT) to verify the content for nuclear safeguards purposes. The results show that the thick quiver lid attenuates the gamma radiation, thereby making gamma radiation based verification from above the quiver difficult.
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- Grape, Erik, et al.
(author)
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Efficient removal of aqueous pharmaceutical pollutants by a robust anionic zirconium ellagate framework
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Other publication (other academic/artistic)abstract
- Emerging organic contaminants (EOCs) in water, such as pharmaceutical compounds, are of growing environmental concern and there is a need to develop new materials and technologies for their efficient removal. A highly porous and exceptionally stable anionic zirconium ellagate metal-organic framework (MOF), denoted SU-102, was developed and utilized to remove EOCs from water, including real municipal wastewater treatment plant (WWTP) effluent. SU-102 adsorbs cationic EOCs with particularly high efficiencies and of the 17 pharmaceutical EOCs detected in WWTP effluent all 9 cationic species were removed with efficiencies of at least 79.0-99.6%, emphasizing the significance of framework charge on selectivity. As a second mechanism of EOC removal, SU-102 photodegraded the antibiotic sulfamethazine under visible light. SU-102 is synthesized from ellagic acid, an edible polyphenol building unit, highlighting the possibility of creating stable high-performance multifunctional materials from sustainably sourced plant-based components.
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