| 1. |
- Bukhanko, Natalia, et al.
(författare)
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Continuous gas phase synthesis of 1-ethyl chloride from ethyl alcohol and hydrochloric acid over Al2O3-based catalysts: the ‘green’ route
- 2013
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 1:8, s. 883-893
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of 1-ethyl chloride in the gas-phase mixture of ethanol and hydrochloric acid over ZnCl2/Al2O3 catalysts was studied in a continuous reactor using both commercial and tailor-made supports. The catalytic materials were characterized by the means of structural (XPS, TEM, XRD, and BET) and catalytic activity (selectivity and conversion) measurements. The reaction parameters such as temperature, pressure, and feedstock flow rates were optimized for the conversion of ethanol to ethyl chloride. The new tailor-made highly porous Al2O3-based catalyst outperformed its commercial counterpart by exhibiting high conversion and selectivity (98%) at the temperature of 325 °C. Long-term stability tests (240 h) confirmed the excellent durability of the tailor-made alumina catalysts. The process demonstrated here poses an efficient and economic “green” large-scale on-site synthesis of this industrially important reactant in industry, where bioethanol is produced and 1-ethyl chloride is necessary, e.g., for ethylation of cellulose and synthetic polymer products. On-site in situ production of ethyl chloride avoids the problems associated with the transportation and storage of toxic and flammable 1-ethyl chloride.
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| 2. |
- Bukhanko, Natalia, et al.
(författare)
-
Extraction of cones, branches, needles and bark from Norway spruce (Picea abies) by supercritical carbon dioxide and soxhlet extractions techniques
- 2020
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Ingår i: Industrial Crops and Products. - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 145
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Tidskriftsartikel (refereegranskat)abstract
- Four low-value Norway spruce tree fractions - cones, branches, needles and bark, were separated from the main tree constituents for investigation of their lipophilic extractives; in order to identify potential sources of important chemicals for future biorefinery applications. For the first time, conventional soxhlet and supercritical carbon dioxide (scCO(2)) extraction techniques were used for extraction of organic compounds from these waste fractions. Identification and quantitation were done by silylation and GCMS. Soxhlet extraction led to total yields of 4-5 % for all fractions except for cones, where the extraction yield was approximately 2 %. With scCO(2) extraction, the highest yield of extractives was obtained from the branches (ca. 5 %), whereas for needles, bark and cones the yield was approximately 3 %, 2 % and 1 %, respectively. Extracts from all four tree fractions contain fatty/resin acids, terpenes, stilbenes, sterols and some long chain alcohols. The components composition was different for each of the four fractions depending on the extraction technique, for example, stilbenes and sterols from branches are effectively obtained only with scCO(2) extraction, whereas soxhlet extraction was more efficient for isolating terpenes, sterols and resin derivatives from cones and bark. Needles extractives, e.g. biologically active sterols and nonacosan-10-ol, important for hydrophobic coatings, can be efficiently obtained by both extraction techniques. These obtained results show that these tree fractions, often discarded or cornbusted, could generate a potentially important source of nutraceutical, pharmaceutical and commodity chemicals.
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| 3. |
- Bukhanko, Natalia, et al.
(författare)
-
Gas phase synthesis of 'green' ethyl chloride
- 2012
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Konferensbidrag (refereegranskat)abstract
- Various xZnCl2/Al2O3 (x = 0-2 wt %) catalysts, and the effect of the type of alumina in the gas phase synthesis of ethyl chloride from ethyl alcohol and HCl were studied. The influence of temperature, pressure, and feed composition was investigated. The nature of catalytic material significantly influenced the performance of the system. The tailor-made high-porous Al2O3 was the optimal catalyst that showed high conversion and selectivity. At 325°C, the conversion obtained was 94-96% and selectivity remained at a constant level of 98% throughout the experiment. This is an abstract of a paper presented at the CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES (Prague, Czech Republic 8/25-29/2012).
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| 4. |
- Bukhanko, Natalia, et al.
(författare)
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Gas phase synthesis of isopropyl chloride from isopropanol and HCl over alumina and flexible 3-D carbon foam supported catalysts
- 2017
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Ingår i: Applied Catalysis A. - : Elsevier. - 0926-860X .- 1873-3875. ; 542:25, s. 212-225
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Tidskriftsartikel (refereegranskat)abstract
- Isopropyl chloride synthesis from isopropanol and HCl in gas phase over ZnCl2 catalysts supported on Al2O3 as well as flexible carbon foam was studied in a continuous reactor. A series of catalytic materials were synthesised and characterised by BET, XPS, SEM, TEM, XRD and NH3-TPD methods. Catalytic activity tests (product selectivity and conversion of reactants) were performed for all materials and optimal reaction conditions (temperature and feedstock flow rates) were found. The results indicate that the highest yield of isopropyl chloride was obtained over 5 wt.% ZnCl2 on commercial Al2O3 (No. II) (95.3%). Determination of product mixture compositions and by-product identification were done using a GC-MS method. Carbon foam variant catalyst, 5 wt.% ZnCl2/C, was found to perform best out of the carbon-supported materials, achieving ∼75% yield of isopropyl chloride. The kinetic model describing the process in a continuous packed bed reactor was proposed and kinetic parameters were calculated. The activation energy for the formation of isopropyl chloride reaction directly from isopropanol and HCl was found to be ∼58 kJ/mol.
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| 5. |
- Bukhanko, Natalia, et al.
(författare)
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Gas phase synthesis of isopropyl chloride from isopropanol and HCl over alumina catalysts
- 2014
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Ingår i: 21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, PRES 2014. - : Czech Society of Chemical Engineering. - 9781510828131 ; , s. 72-73
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Konferensbidrag (refereegranskat)
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| 6. |
- Bukhanko, Natalia, et al.
(författare)
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Kinetic modeling of gas phase synthesis of ethyl chloride from ethanol and HCl in fixed bed reactor
- 2016
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Ingår i: Chemical Engineering Science. - : Elsevier BV. - 0009-2509 .- 1873-4405. ; 142, s. 310-317
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Tidskriftsartikel (refereegranskat)abstract
- Kinetic modeling of gas-phase synthesis of ethyl chloride from ethanol and hydrochloric acid over high porous Al2O3 and 2 wt% ZnCl2/Al2O3 catalysts was studied in a continuous plug flow reactor in the temperature range of 200–325 °C. Two rival kinetic models were proposed that both describe the kinetics well. The kinetic parameters of the reaction were determined and activation energy values for ethyl chloride formation from ethyl alcohol and diethyl ether reactions were calculated.
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| 7. |
- Bukhanko, Natalia, et al.
(författare)
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Supercritical extraction of waxes and lipids from biomass: A valuable first step towards an integrated biorefinery
- 2018
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 177, s. 684-698
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Tidskriftsartikel (refereegranskat)abstract
- The decline in petrochemical wax supply coupled with the ever-growing demand for bio-products means that the development of a sustainable process to renewably sourced waxes is paramount. This review focuses on recent advances in supercritical extraction as a clean efficient process for extracting waxes from waste biomass as a part of a holistic biorefinery. The use of supercritical carbon dioxide leads to reductions in solvent waste and leaves no solvent residues meaning that the biomass can further processed without the need for energy-intensive solvent removal steps. This technology crucially improves the downstream conversion of residual cellulosic biomass for the sustainable production of sugars, consumer products and biofuels (up to a 40% increase in ethanol production) leading to higher energy efficiencies and higher economic returns. Supercritical carbon dioxide extraction is not only an important technology for the cleaner production of waxes, it is a sustainable pre-treatment of biomass as part of an integrated holistic biorefinery and significantly, it can improve the safety of products, e.g. less off gassing of wood pellets. (C) 2018 Elsevier Ltd. All rights reserved.
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