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Now showing items 1 - 5 of 5

  • A new model for the fractionation of fish oil FAEEs

    Pieck, Carlos Ariel   Crampon, Christelle   Charton, Frederic   Badens, Elisabeth  

    In this work, the supercritical fractionation of fatty acid ethyl esters derived from fish oil was carried out with carbon dioxide at 333 K and 14.5 MPa. The feed mixture is very complex, with over 80 different compounds detected by GC. Among them, the EicosaPentaenoic Acid (EPA) and DodecaHexaenoic Acid (DHA) ethyl esters are of major industrial interest since the consumption of these omega-3 acids has been linked to a reduced risk of cardiovascular diseases. The influence of the process parameters on the separation efficiency is an important point for an economic analysis of the overall purification process. First, the partition of the feed mixture was determined for different solvent-to-feed ratios varying between 21.8 and 143; the extract yield (i.e. the mass fraction of feed recovered as extract) has been calculated for each condition. Then, a new simplified equilibrium-stage model was developed and applied to the mixture. Supposing a constant distribution ratio, this model is able to correlate the influence of the solvent-to-feed ratio (through a calculated extract yield) on the concentration of the major 24 compounds present either in the feed or in the extract and raffinate, including components with low, medium and high distribution ratios. (C) 2016 Elsevier B.V. All rights reserved.
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  • Supercritical CO2 extraction of molybdenum-ligand complexes from sulfuric solutions

    Hung, Laurence   Hertz, Audrey   Hartmann, Didier   Charton, Frederic   Boutin, Olivier  

    The development of environmental-friendly process for strategic metal extraction, limiting organic solvent use and effluent production, appears to be quite a challenging purpose. Production of pure molybdenum using supercritical CO2 extraction process, from sulfuric solution obtained by ore or used catalyst leaching, has been evaluated. Two organic ligands, trioctylamine and 2-ethylhexyl 2-ethylhexylphosphonic acid, were studied to extract Mo as metal complexes solubilized in supercritical CO2. Extraction with trioctylamine revealed to be non-efficient due to a lack of Mo-trioctylamine complex solubility in CO2, even if extraction selectivity of molybdenum versus iron impurity was interesting. On the contrary, extraction with 2-ethylhexyl 2-ethylhexylphosphonic acid leads to high Mo collection efficiency (up to 90% in 7 h). However, no selectivity was observed between molybdenum and zirconium. The selectivity of 2-ethylhexyl 2-ethylhexylphosphonic acid towards molybdenum in presence of iron was better but clearly decreased in presence of zirconium. (C) 2016 Elsevier B.V. All rights reserved.
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  • Extraction of Cobalt Ion from Textile Using a Complexing Macromolecular Surfactant in Supercritical Carbon Dioxide

    Chirat, Mathieu   Ribaut, Tiphaine   Clerc, Sebastien   Charton, Frederic   Fournel, Bruno   Lacroix-Desmazes, Patrick  

    Cobalt ion under the form of cobalt nitrate is removed from a textile lab coat using supercritical carbon dioxide extraction. The process involves a macromolecular additive of well-defined architecture, acting both as a surfactant and a complexing agent. The extraction efficiency of cobalt reaches 66% when using a poly(1,1,2,2-tetrahydroperfluorodecylacrylate-co-vinylbenzylphosphonic diacid) gradient copolymer in the presence of water at 160 bar and 40 degrees C. The synergy of the two additives, namely the copolymer and water which are useless if used separately, is pointed out. The potential of the supercritical carbon dioxide process using complexing macromolecular surfactant lies in the ability to modulate the complexing unit as a function of the metal as well as the architecture of the surface-active agent for applications ranging for instance from nuclear decontamination to the recovery of strategic metals.
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  • Process simulation and energetic analysis of different supercritical water gasification systems for the valorisation of biomass

    Ondze, Felicite   Ferrasse, Jean-Henry   Boutin, Olivier   Ruiz, Jean-Christophe   Charton, Frederic  

    The energetic efficiency for the supercritical gasification of biomass is studied for three cases: hydrogen and methane production, heat and electricity cogeneration. Experimental results from the gasification of glucose are used to represent the gasifier. The other unit operations are simulated using the software ProsimPlus through thermodynamic equilibrium calculations. Simulations are conducted at different pressure, temperature and initial biomass concentration. The energetic and exergetic yields are calculated, as well as the minimum heat requirement estimated from a pinch analysis. All the results are then exploited to determine optimal conditions for two systems: adiabatic and isothermal. The optimal temperature ranges from 584 to 626 degrees C, whereas the optimal initial concentration ranges from 51 to 87 gL(-1). The system giving the best result in term of global energetic optimisation is methane production in isothermal conditions, followed by methane production in adiabatic conditions. The optimal energy efficiencies are 94% and 91% respectively.
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  • Combined Extraction Processes of Lipid from Chlorella vulgaris Microalgae: Microwave Prior to Supercritical Carbon Dioxide Extraction

    Dejoye, Celine   Vian, Maryline Abert   Lumia, Guy   Bouscarle, Christian   Charton, Frederic   Chemat, Farid  

    Extraction yields and fatty acid profiles from freeze-dried Chlorella vulgaris by microwave pretreatment followed by supercritical carbon dioxide (MW-SCCO(2)) extraction were compared with those obtained by supercritical carbon dioxide extraction alone (SCCO(2)). Work performed with pressure range of 20-28 Mpa and temperature interval of 40-70 degrees C, gave the highest extraction yield (w/w dry weight) at 28 MPa/40 degrees C. MW-SCCO(2) allowed to obtain the highest extraction yield (4.73%) compared to SCCO(2) extraction alone (1.81%). Qualitative and quantitative analyses of microalgae oil showed that palmitic, oleic, linoleic and alpha-linolenic acid were the most abundant identified fatty acids. Oils obtained by MW-SCCO(2) extraction had the highest concentrations of fatty acids compared to SCCO(2) extraction without pretreatment. Native form, and microwave pretreated and untreated microalgae were observed by scanning electronic microscopy (SEM). SEM micrographs of pretreated microalgae present tearing wall agglomerates. After SCCO(2), microwave pretreated microalgae presented several micro cracks; while native form microalgae wall was slightly damaged.
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