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Design and economic analysis of the process for biodiesel fuel production from transesterificated rapeseed oil using supercritical methanol / Youngsub Lim in Industrial & engineering chemistry research, Vol. 48 N° 11 (Juin 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 11 (Juin 2009) . - pp. 5370–5378 Titre : Design and economic analysis of the process for biodiesel fuel production from transesterificated rapeseed oil using supercritical methanol Type de document : texte imprimé Auteurs : Youngsub Lim, Auteur ; Hong-shik Lee, Auteur ; Youn Woo Lee, Auteur Année de publication : 2009 Article en page(s) : pp. 5370–5378 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Biodiesel  fuel  production  Alkali-catalyzed  process  Supercritical  biodiesel  process Résumé : A supercritical process for biodiesel fuel production is generally known to be less profitable than the alkali-catalyzed process due to high temperature and pressure requirements for the supercritical reaction. Only a few approaches have been proposed using experimental results to design a supercritical biodiesel process and to assess its profitability compared to the alkali-catalyzed process. In this study, a design for a supercritical biodiesel process was suggested and its economic performance with three different reaction conditions was simulated in the comparison with the conventional alkali-catalyzed process. It was found that the total capital cost was higher in all three cases of the supercritical process than in the alkali-catalyzed process due to the high cost of pumps, heaters, and heat exchangers. However, the total manufacturing cost of the supercritical process was lower than that of the alkali-catalyzed process due to the higher glycerol credit and the lack of a requirement for catalyst or solvent. The supercritical process can produce high-purity glycerol more easily that does not contain any water, which is unavoidable in the washing step of the alkali-catalyzed process. The higher steam cost in the supercritical process was compensated for by catalyst and solvent costs in the alkali-catalyzed process. Overall, one of the supercritical processes resulted in shorter payout time than the alkali-catalyzed process even when virgin oil was used as one of the raw materials, because the lower total manufacturing cost made up for the increased total capital cost. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005287 [article] Design and economic analysis of the process for biodiesel fuel production from transesterificated rapeseed oil using supercritical methanol [texte imprimé] / Youngsub Lim, Auteur ; Hong-shik Lee, Auteur ; Youn Woo Lee, Auteur . - 2009 . - pp. 5370–5378. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 11 (Juin 2009) . - pp. 5370–5378 Mots-clés : Biodiesel  fuel  production  Alkali-catalyzed  process  Supercritical  biodiesel  process Résumé : A supercritical process for biodiesel fuel production is generally known to be less profitable than the alkali-catalyzed process due to high temperature and pressure requirements for the supercritical reaction. Only a few approaches have been proposed using experimental results to design a supercritical biodiesel process and to assess its profitability compared to the alkali-catalyzed process. In this study, a design for a supercritical biodiesel process was suggested and its economic performance with three different reaction conditions was simulated in the comparison with the conventional alkali-catalyzed process. It was found that the total capital cost was higher in all three cases of the supercritical process than in the alkali-catalyzed process due to the high cost of pumps, heaters, and heat exchangers. However, the total manufacturing cost of the supercritical process was lower than that of the alkali-catalyzed process due to the higher glycerol credit and the lack of a requirement for catalyst or solvent. The supercritical process can produce high-purity glycerol more easily that does not contain any water, which is unavoidable in the washing step of the alkali-catalyzed process. The higher steam cost in the supercritical process was compensated for by catalyst and solvent costs in the alkali-catalyzed process. Overall, one of the supercritical processes resulted in shorter payout time than the alkali-catalyzed process even when virgin oil was used as one of the raw materials, because the lower total manufacturing cost made up for the increased total capital cost. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005287

Dispersion polymerization of methyl methacrylate using poly(HDFDMA-co-MMA) as a surfactant in supercritical carbon dioxide / Jungin Shin in Industrial & engineering chemistry research, Vol. 47 n°15 (Août 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5680–5685 Titre : Dispersion polymerization of methyl methacrylate using poly(HDFDMA-co-MMA) as a surfactant in supercritical carbon dioxide Type de document : texte imprimé Auteurs : Jungin Shin, Auteur ; Kyung Shil Oh, Auteur ; Won Bae, Auteur ; Youn Woo Lee, Auteur Année de publication : 2008 Article en page(s) : p. 5680–5685 Note générale : Bibliogr. p. 5684-5685 Langues : Anglais (eng) Mots-clés : Methyl  methacrylate;  Dispersion  polymerization Résumé : New surfactants, random copolymers of heptadecafluorodecyl methacrylate (HDFDMA) and methyl methacrylate (MMA), were synthesized at 343.2 K and 30 MPa in supercritical carbon dioxide (scCO2) with varying HDFDMA/MMA ratios. 1H NMR and FT-IR were used to confirm the structure and to determine the composition of the resulting copolymers. The phase behavior of poly(HDFDMA-co-MMA) in CO2 was obtained by means of a variable volume view cell, which will be used to select the polymerization condition. After that, dispersion polymerization of methyl methacrylate (MMA) in scCO2 was performed using 2,2′-azobis(isobutyronitrile) (AIBN) as the initiator and poly(HDFDMA-co-MMA) with various MMA mole fraction as a surfactant. The new surfactant, poly(HDFDMA-co-MMA), whose MMA content is lower than 12.3 wt %, shows comparable capacity to produce PMMA particles compared to poly(HDFDMA) surfactant. The resulting PMMA particles, such as those produced using poly(HDFDMA) homopolymer as a surfactant, could also be produced with poly(HDFDMA-co-MMA) up to 12.3 wt % MMA. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070995v [article] Dispersion polymerization of methyl methacrylate using poly(HDFDMA-co-MMA) as a surfactant in supercritical carbon dioxide [texte imprimé] / Jungin Shin, Auteur ; Kyung Shil Oh, Auteur ; Won Bae, Auteur ; Youn Woo Lee, Auteur . - 2008 . - p. 5680–5685. Bibliogr. p. 5684-5685 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5680–5685 Mots-clés : Methyl  methacrylate;  Dispersion  polymerization Résumé : New surfactants, random copolymers of heptadecafluorodecyl methacrylate (HDFDMA) and methyl methacrylate (MMA), were synthesized at 343.2 K and 30 MPa in supercritical carbon dioxide (scCO2) with varying HDFDMA/MMA ratios. 1H NMR and FT-IR were used to confirm the structure and to determine the composition of the resulting copolymers. The phase behavior of poly(HDFDMA-co-MMA) in CO2 was obtained by means of a variable volume view cell, which will be used to select the polymerization condition. After that, dispersion polymerization of methyl methacrylate (MMA) in scCO2 was performed using 2,2′-azobis(isobutyronitrile) (AIBN) as the initiator and poly(HDFDMA-co-MMA) with various MMA mole fraction as a surfactant. The new surfactant, poly(HDFDMA-co-MMA), whose MMA content is lower than 12.3 wt %, shows comparable capacity to produce PMMA particles compared to poly(HDFDMA) surfactant. The resulting PMMA particles, such as those produced using poly(HDFDMA) homopolymer as a surfactant, could also be produced with poly(HDFDMA-co-MMA) up to 12.3 wt % MMA. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070995v

Optical properties of red algae fibers / Yung Bum Seo in Industrial & engineering chemistry research, Vol. 49 N° 20 (Octobre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 20 (Octobre 2010) . - pp. 9830–9833 Titre : Optical properties of red algae fibers Type de document : texte imprimé Auteurs : Yung Bum Seo, Auteur ; Youn Woo Lee, Auteur ; Chun Han Lee, Auteur Année de publication : 2011 Article en page(s) : pp. 9830–9833 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Red  algae  fibers Résumé : Red algae fibers extracted from red algae (seaweed) showed very high opacity when used in the manufacture of white paper. For a basis weight of 60 g/m2, over 90% opacity was observed in paper made from red algae fibers without the aid of mineral fillers, whereas papers made from wood fibers had 70−80% opacity. Mercury porosimetry and light reflectance measurements at various wavelengths were used to investigate the origin of such high opacities in red algae fibers. The results revealed that red algae fibers had an extraordinarily high specific surface area on account of their very narrow widths (2−4 μm) and short lengths (500−800 μm). This unique property of red algae fibers can be best utilized for manufacturing highly opaque, premium-grade, lightweight printing papers without lowering the paper strength properties. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101194g [article] Optical properties of red algae fibers [texte imprimé] / Yung Bum Seo, Auteur ; Youn Woo Lee, Auteur ; Chun Han Lee, Auteur . - 2011 . - pp. 9830–9833. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 20 (Octobre 2010) . - pp. 9830–9833 Mots-clés : Red  algae  fibers Résumé : Red algae fibers extracted from red algae (seaweed) showed very high opacity when used in the manufacture of white paper. For a basis weight of 60 g/m2, over 90% opacity was observed in paper made from red algae fibers without the aid of mineral fillers, whereas papers made from wood fibers had 70−80% opacity. Mercury porosimetry and light reflectance measurements at various wavelengths were used to investigate the origin of such high opacities in red algae fibers. The results revealed that red algae fibers had an extraordinarily high specific surface area on account of their very narrow widths (2−4 μm) and short lengths (500−800 μm). This unique property of red algae fibers can be best utilized for manufacturing highly opaque, premium-grade, lightweight printing papers without lowering the paper strength properties. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101194g

Polymerization of n-vinylcarbazole in supercritical carbon dioxide and in a supercritical region of a carbon dioxide and dimethyl ether mixture / Kyung Shil Oh in Industrial & engineering chemistry research, Vol. 47 n°15 (Août 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5734-5741 Titre : Polymerization of n-vinylcarbazole in supercritical carbon dioxide and in a supercritical region of a carbon dioxide and dimethyl ether mixture Type de document : texte imprimé Auteurs : Kyung Shil Oh, Auteur ; Won Bae, Auteur ; Youn Woo Lee, Auteur ; Hwayong Kim, Auteur Année de publication : 2008 Article en page(s) : p. 5734-5741 Note générale : Bibliogr. p. 5740-5741 Langues : Anglais (eng) Mots-clés : N-vinylcarbazole  --  polimerization;  Carbon  dioxide;  Fluorine-based Résumé : Spherical poly(N-vinylcarbazole) (PVK) particles were synthesized by polymerization of N-vinylcarbazole (NVCA) in supercritical carbon dioxide (scCO2) and a supercritical region of a CO2 and dimethyl ether (DME) mixture using a fluorine-based [poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl methacrylate)] [poly(HDFDMA)] polymer as the surfactant and 2,2′-azobisisobutyronitrile (AIBN) as the initiator. The spherical PVK particles could be consistently produced under the given experimental conditions. The PVK particle size showed a bimodal distribution when scCO2 was used as solvent. Therefore DME was added to the system as a cosolvent. The resulting particle size was shown to be dependent on the amount of surfactant and DME added to the system. As the ratio of DME increased, the average molecular mass of the PVK particles decreased. The effects of surfactant and initiator concentrations were investigated with respect to the morphology, size, and molecular mass of the PVK particles. The effects of the addition of a mixed solvent consisting of CO2 + DME on polymeric particle morphology, size, and molecular mass of polymers were also studied and are discussed herein. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071526w [article] Polymerization of n-vinylcarbazole in supercritical carbon dioxide and in a supercritical region of a carbon dioxide and dimethyl ether mixture [texte imprimé] / Kyung Shil Oh, Auteur ; Won Bae, Auteur ; Youn Woo Lee, Auteur ; Hwayong Kim, Auteur . - 2008 . - p. 5734-5741. Bibliogr. p. 5740-5741 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5734-5741 Mots-clés : N-vinylcarbazole  --  polimerization;  Carbon  dioxide;  Fluorine-based Résumé : Spherical poly(N-vinylcarbazole) (PVK) particles were synthesized by polymerization of N-vinylcarbazole (NVCA) in supercritical carbon dioxide (scCO2) and a supercritical region of a CO2 and dimethyl ether (DME) mixture using a fluorine-based [poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl methacrylate)] [poly(HDFDMA)] polymer as the surfactant and 2,2′-azobisisobutyronitrile (AIBN) as the initiator. The spherical PVK particles could be consistently produced under the given experimental conditions. The PVK particle size showed a bimodal distribution when scCO2 was used as solvent. Therefore DME was added to the system as a cosolvent. The resulting particle size was shown to be dependent on the amount of surfactant and DME added to the system. As the ratio of DME increased, the average molecular mass of the PVK particles decreased. The effects of surfactant and initiator concentrations were investigated with respect to the morphology, size, and molecular mass of the PVK particles. The effects of the addition of a mixed solvent consisting of CO2 + DME on polymeric particle morphology, size, and molecular mass of polymers were also studied and are discussed herein. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071526w