| 1. |
- Davisayahvorakul, Ratikorn, et al.
(författare)
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Glycerol Ketal Biobased Product Preparation from Biomass-Derived Reactants Using an H-ZSM-5 Catalyst for Oil Color Painting Application
- 2024
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Ingår i: ACS Sustainable Chemistry and Engineering. - 2168-0485. ; 12:11, s. 4598-4604
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Tidskriftsartikel (refereegranskat)abstract
- Condensation of glycerol with bioderived carbonyls yields cyclic ketals with unique properties. In this study, efficient solvent-free heterogeneously catalyzed ketalization has been achieved to give the corresponding products in good to excellent yields. Substrate-to-glycerol ratios of 1:1 have been used; the reactions were performed at 120 °C for 30 min. By using an acid-treated H-ZSM-5 catalyst, high selectivity to a five-membered ring was achieved. Furthermore, the catalyst could be recycled up to 4 times without losing activity. The ketal from glycerol and levulinic acid (GLK) was isolated and applied as a solvent in oil color paint and showed advantageous properties over commercial paint solvents in terms of aging.
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| 2. |
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| 3. |
- Di Francesco, Davide, et al.
(författare)
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OrganoSoxhlet : circular fractionation to produce pulp for textiles using CO2 as acid source
- 2021
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 23:23, s. 9401-9405
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Tidskriftsartikel (refereegranskat)abstract
- Organosolv pulping performed in a high-pressure Soxhlet extractor using carbon dioxide as a mild and recyclable acid is described. The system reached a liquid to wood ratio of 6.6 yielding 43 wt% of dissolving grade quality pulp from Populus trichocarpa. The set-up enabled to run reductive catalytic fractionation to yield a lipophilic lignin oil without affecting the performance nor the purity of the final pulp.
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| 4. |
- Muangmeesri, Suthawan, et al.
(författare)
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Holistic Valorization of Hemp through Reductive Catalytic Fractionation
- 2021
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 9:51, s. 17207-17213
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Tidskriftsartikel (refereegranskat)abstract
- Despite the increased use of hemp fiber, negligible attention has been given to upgrade the hemp hurd, which constitutes up to 70 wt % of the hemp stalk and is currently considered a low-value byproduct. In this work, valorization of hemp hurd was performed by reductive catalytic fractionation (RCF) in the presence of a metal catalyst. We found an unexpectedly high yield of monophenolic compounds (38.3 wt %) corresponding to above 95% of the theoretical maximum yield. The high yield is explained by both a thin cell wall and high S-lignin content. In addition, organosolv pulping was performed to generate a pulp that was bleached to produce dissolving-grade pulp suitable for textile fiber production (viscosity, 898 mL/g; ISO-brightness, 90.2%) and nanocellulose. Thus, we have demonstrated a novel value chain from a low-value side stream of hemp fiber manufacture that has the potential to increase textile fiber production with 100% yield and also give bio-oil for green chemicals.
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| 5. |
- Muangmeesri, Suthawan, 1997-, et al.
(författare)
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Recycling of Polyesters by Organocatalyzed Methanolysis Depolymerization : Environmental Sustainability Evaluated by Life Cycle Assessment
- 2024
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 12:10, s. 4114-4120
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Tidskriftsartikel (refereegranskat)abstract
- Polyethylene terephthalate (PET) is one of the most common plastics and can be cascaded mechanically during its life cycle. However, recycling affects the mechanical properties of the material, and the virgin material is constantly in demand. If a worn material could be depolymerized to its chemical building blocks, then a virgin polymer could be generated from old fibers. In this work, we have developed a benign organo-catalytic depolymerization of PET to yield dimethyl terephthalate (DMT) and ethylene glycol (EG) without the need for purification of generated monomers. By recirculating the solvent and organo-catalyst, a solvent/substrate ratio of 3:1 was achieved. The depolymerization was successfully applied to other polyesters, polycarbonates, and polycotton. The cotton isolated from the polycotton depolymerization was successfully processed into viscose fibers with a tenacity in the range of nonwaste cotton-derived viscose filaments. The global warming potential (GWP) of PET depolymerization was evaluated by using life cycle assessment (LCA). The GWP of 1 kg PET recycling is 2.206 kg CO2 equivalent, but the process produces DMT, EG, and heat, thereby avoiding the emissions equivalent to 4.075 kg CO2 equivalent from the DMT, EG, and steam-energy production through conventional pathways. Thus, the net result potentially avoids the emission of 1.88 kg of CO2 equivalent. The impact of this process is lower than that of waste PET incineration and conventional PET recycling technologies.
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| 6. |
- Witthayolankowit, Kuntawit, et al.
(författare)
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Valorization of Tops and Branches to Textile Fibers and Biofuel : Value Chain Explored Experimentally; Environmental Sustainability Evaluated by Life Cycle Assessment
- 2023
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 12:1, s. 526-533
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Tidskriftsartikel (refereegranskat)abstract
- To make biorefining more environmentally sustainable, preferably residues from forestry should be used and more than one fraction should be upgraded. A third of raw materials from forestry & horbar;tops and branches (T & B)― are either left in the forests or collected and incinerated to a low value. Herein, we apply a fast fractionation to valorize two of the fractions of this forestry residue. The cellulose is converted to textile fibers and all the lignin to hydrocarbons. The environmental sustainability of the novel value chain was studied by life cycle assessment (LCA), and benefits were found in four out of five impact categories. These are important steps to increase fiber production without affecting environmental impact, making biorefining competitive.
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