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| 2. |
- Lebedeva, Daria, 1994-
(författare)
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Valorization of low-value lignocellulosic side-streams
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The development of novel pathways for valorizing low-value streams from pulp, forest, and agricultural industries is crucial for realizing a circular bioeconomy and addressing the needs of both platform chemicals and fuels. Utilizing hemicellulose and lignin as biomass-derived feedstocks facilitates the production of sustainable liquid hydrocarbons, with catalytic hydrodeoxygenation being a key process. In the utilization of hemicellulose for the synthesis of liquid hydrocarbons, the approach involves recovering hemicellulosic sugars from wood and transforming them into furfural, which undergoes catalytic hydrodeoxygenation using a noble metal/zeolite tandem catalyst. This results in the production of pentane as the primary product. The process also generates C7–C10 hydrocarbons through bimolecular condensation of oxygenated intermediates alongside the formation of aromatic structures. Another approach involves a three-step transformation of furfural, including furanic ring rearrangement and [2+2] cycloaddition, which produces a C10 oxygenated precursor with a 4-membered ring. Catalytic hydrodeoxygenation of this precursor results in the formation of cyclobutane-containing hydrocarbons for sustainable aviation fuel applications.In the utilization of lignin for the synthesis of liquid hydrocarbons, the approach involves lignin isolation from biomass and its direct catalytic hydrodeoxygenation into valuable platform chemicals and fuels. Guaiacol serves as a lignin model compound, facilitating optimization of the hydrotreatment process and giving insights into the distribution of the products. The hydrodeoxygenation of two different lignins, isolated from biomass by organosolv and soda pulping, yields bio-oils rich in hydrocarbons and suitable for transportation fuel applications.
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- Obydenkova, Svetlana V., et al.
(författare)
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Environmental economics of lignin derived transport fuels
- 2017
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 243, s. 589-599
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Tidskriftsartikel (refereegranskat)abstract
- This paper explores the environmental and economic aspects of fast pyrolytic conversion of lignin, obtained from 2G ethanol plants, to transport fuels for both the marine and automotive markets. Various scenarios are explored, pertaining to aggregation of lignin from several sites, alternative energy carries to replace lignin, transport modalities, and allocation methodology. The results highlight two critical factors that ultimately determine the economic and/or environmental fuel viability. The first factor, the logistics scheme, exhibited the disadvantage of the centralized approach, owing to prohibitively expensive transportation costs of the low energy-dense lignin. Life cycle analysis (LCA) displayed the second critical factor related to alternative energy carrier selection. Natural gas (NG) chosen over additional biomass boosts well-to-wheel greenhouse gas emissions (WTW GHG) to a level incompatible with the reduction targets set by the U.S. renewable fuel standard (RFS). Adversely, the process’ economics revealed higher profits vs. fossil energy carrier.
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| 4. |
- Spezzati, Guilia, et al.
(författare)
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Synthesis, Physicochemical Characterization, and Cytotoxicity Assessment of CeO2 Nanoparticles with Different Morphologies
- 2017
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Ingår i: European Journal of Inorganic Chemistry. - : Wiley-VCH Verlag. - 1434-1948 .- 1099-1948 .- 1099-0682. ; 2017:25, s. 3184-3190
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Tidskriftsartikel (refereegranskat)abstract
- With the growing use of nanomaterials, it is essential to carefully determine whether they represent a risk for potential users. So far, validated stand-alone methods that allow a proper risk assessment are still rare. In the present study, the cytotoxicity of CeO2 nanoparticles has been assessed. For this purpose, a variety of well-defined CeO2 nanoparticles has been prepared by using either hydrothermal synthesis or flame spray pyrolysis (FSP), resulting in nanoparticles of different morphologies and sizes. The FSP technique is known to produce particles of a very small size (in the range of nanometers), which can easily become airborne. We employed a characterization procedure that makes use of physicochemical techniques, comprising N2 physisorption, XRD, TEM, as well as ζ-potential and surface-charge measurements. The cytotoxicity of the nanoparticles was evaluated in vitro on two different human lung cell lines (A549 and MRC-5). The tests showed that, despite the differences in surface properties, size, and morphologies, neither of the CeO2 samples gave rise to a cytotoxic response.
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