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Catalytic and non-catalytic supercritical water gasification of microalgae and glycerol / Anand G. Chakinala in Industrial & engineering chemistry research, Vol. 49 N° 3 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1113–1122 Titre : Catalytic and non-catalytic supercritical water gasification of microalgae and glycerol Type de document : texte imprimé Auteurs : Anand G. Chakinala, Auteur ; Derk W. F. (Wim) Brilman, Auteur ; Wim P.M. van Swaaij, Auteur Année de publication : 2010 Article en page(s) : pp. 1113–1122 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalytic--non-catalytic--water  gasification--microalgae--  glycerol Résumé : In this study, we present the gasification of microalgae (Chlorella vulgaris) and glycerol in supercritical water (SCW) using batch (quartz capillaries) and continuous flow reactors. Preliminary tests of algae gasification were done with quartz capillaries at varying operating conditions such as temperature (400−700 °C), reaction time (1−15 min), and the addition of catalysts. The dry gas composition of uncatalyzed gasification of algae in SCW mainly comprised of CO2, CO, CH4, H2, and some C2−C3 compounds. Higher temperatures, low algae concentrations, and longer residence times favored the algae gasification efficiency (GE). The addition of catalysts to the capillaries resulted in higher yields of hydrogen and lower CO yields via enhanced water−gas shift activity. The addition of catalysts accelerated the gasification efficiency up to a maximum of 84% at 600 °C and 2 min reaction time with nickel-based catalysts. Complete gasification is achieved at higher temperatures (700 °C) and with excess amounts of (Ru/TiO2) catalyst. To elucidate part of the difficulties related to the SCWG of algae, reforming of a model compound (here glycerol) in SCW was carried out in a continuous flow reactor in the presence of additives like amino acids (l-alanine, glycine, and l-proline) and alkali salt (K2CO3) and combinations thereof. The amino acids l-alanine and glycine have a minor effect on the gasification process of glycerol, and a significant reduction of the gasification efficiency was observed in the presence of l-proline. Coke formation and colorization of the reactor effluent were more noticeable with glycerol−amino acid mixtures. In the absence of amino acids, the glycerol solution gasified without any coke formation and colorization of the reactor effluent. Again this effect was more pronounced in the presence of l-proline. The addition of K2CO3 enhanced the glycerol gasification efficiency and increased the hydrogen yields promoting the water−gas shift reaction. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008293 [article] Catalytic and non-catalytic supercritical water gasification of microalgae and glycerol [texte imprimé] / Anand G. Chakinala, Auteur ; Derk W. F. (Wim) Brilman, Auteur ; Wim P.M. van Swaaij, Auteur . - 2010 . - pp. 1113–1122. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1113–1122 Mots-clés : Catalytic--non-catalytic--water  gasification--microalgae--  glycerol Résumé : In this study, we present the gasification of microalgae (Chlorella vulgaris) and glycerol in supercritical water (SCW) using batch (quartz capillaries) and continuous flow reactors. Preliminary tests of algae gasification were done with quartz capillaries at varying operating conditions such as temperature (400−700 °C), reaction time (1−15 min), and the addition of catalysts. The dry gas composition of uncatalyzed gasification of algae in SCW mainly comprised of CO2, CO, CH4, H2, and some C2−C3 compounds. Higher temperatures, low algae concentrations, and longer residence times favored the algae gasification efficiency (GE). The addition of catalysts to the capillaries resulted in higher yields of hydrogen and lower CO yields via enhanced water−gas shift activity. The addition of catalysts accelerated the gasification efficiency up to a maximum of 84% at 600 °C and 2 min reaction time with nickel-based catalysts. Complete gasification is achieved at higher temperatures (700 °C) and with excess amounts of (Ru/TiO2) catalyst. To elucidate part of the difficulties related to the SCWG of algae, reforming of a model compound (here glycerol) in SCW was carried out in a continuous flow reactor in the presence of additives like amino acids (l-alanine, glycine, and l-proline) and alkali salt (K2CO3) and combinations thereof. The amino acids l-alanine and glycine have a minor effect on the gasification process of glycerol, and a significant reduction of the gasification efficiency was observed in the presence of l-proline. Coke formation and colorization of the reactor effluent were more noticeable with glycerol−amino acid mixtures. In the absence of amino acids, the glycerol solution gasified without any coke formation and colorization of the reactor effluent. Again this effect was more pronounced in the presence of l-proline. The addition of K2CO3 enhanced the glycerol gasification efficiency and increased the hydrogen yields promoting the water−gas shift reaction. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008293

Effect of temperature in fluidized bed fast pyrolysis of biomass / Roel J. M. Westerhof in Industrial & engineering chemistry research, Vol. 49 N° 3 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1160–1168 Titre : Effect of temperature in fluidized bed fast pyrolysis of biomass : oil quality assessment in test units Type de document : texte imprimé Auteurs : Roel J. M. Westerhof, Auteur ; Derk W. F. (Wim) Brilman, Auteur ; Wim P.M. van Swaaij, Auteur ; Sacha R. A. Kersten, Auteur Année de publication : 2010 Article en page(s) : pp. 1160–1168 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Effect--Temperature--Fluidized--Pyrolysis--Biomass--Oil--Quality  Assessment--Test  Units Résumé : Pine wood was pyrolyzed in a 1 kg/h fluidized bed fast pyrolysis reactor that allows a residence time of pine wood particles up to 25 min. The reactor temperature was varied between 330 and 580 °C to study the effect on product yields and oil composition. Apart from the physical−chemical analysis, a pyrolysis oil quality assessment has been performed by using two applications. The pyrolysis oils were tested in a laboratory scale atomizer and in a hydrodeoxygenation unit for upgrading/stabilizing of the pyrolysis oil. The pyrolysis oil yield increases from 330 to 450 °C, is nearly constant between 450 and 530 °C, and decreases again at a pyrolysis temperature of 580 °C. At temperatures of 360 and 580 °C, total pyrolysis oil yields of, respectively, 58 and 56 dry wt % can still be obtained. The produced amount of water is already significant at a reactor temperature of 360 °C and becomes constant at a temperature of 400 °C. At a temperature of 580 °C, the water production starts to decrease slightly. Initially the number average molecular weight of the pyrolysis oil increases at increasing temperatures, which is ascribed to the observed increase in concentration of water insoluble compound in the pyrolysis oil. At a temperature of 580 °C, the number average molecular weight, viscosity, and the amount of produced water insoluble compounds decreases. The oil obtained at a pyrolysis temperature of 360 °C produced less char, 2 versus 5 wt %, compared to the oil obtained at a pyrolysis temperature of 530 °C in our atomizer/gasifier. About 100% of the carbon goes to the gas phase compared to 84% for the oil obtained at a pyrolysis temperature of 530 °C. Therefore, the 360 °C oil has a better quality for this unit under the applied conditions (850 °C and droplet sizes of 50± μm) Testing the three pyrolysis oils (pyrolysis temperatures of 330, 530, and 580 °C) in the hydrodeoxygenation unit showed that pyrolysis oil with a lower viscosity resulted in deoxygenated oil of lower viscosity. The oxygen content of the three oils was almost the same, but the yield of the deoxygenated oils obtained at a pyrolysis temperature of 330 °C was significantly lower. Together with chemical and physical analyzes of the pyrolysis oils, feeding the pyrolysis oil into a test units relevant for applications, direct information on the effect of varied pyrolysis process parameters on the quality and applicability of the pyrolysis oil is obtained. Note de contenu : Bibiogra. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900885c [article] Effect of temperature in fluidized bed fast pyrolysis of biomass : oil quality assessment in test units [texte imprimé] / Roel J. M. Westerhof, Auteur ; Derk W. F. (Wim) Brilman, Auteur ; Wim P.M. van Swaaij, Auteur ; Sacha R. A. Kersten, Auteur . - 2010 . - pp. 1160–1168. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1160–1168 Mots-clés : Effect--Temperature--Fluidized--Pyrolysis--Biomass--Oil--Quality  Assessment--Test  Units Résumé : Pine wood was pyrolyzed in a 1 kg/h fluidized bed fast pyrolysis reactor that allows a residence time of pine wood particles up to 25 min. The reactor temperature was varied between 330 and 580 °C to study the effect on product yields and oil composition. Apart from the physical−chemical analysis, a pyrolysis oil quality assessment has been performed by using two applications. The pyrolysis oils were tested in a laboratory scale atomizer and in a hydrodeoxygenation unit for upgrading/stabilizing of the pyrolysis oil. The pyrolysis oil yield increases from 330 to 450 °C, is nearly constant between 450 and 530 °C, and decreases again at a pyrolysis temperature of 580 °C. At temperatures of 360 and 580 °C, total pyrolysis oil yields of, respectively, 58 and 56 dry wt % can still be obtained. The produced amount of water is already significant at a reactor temperature of 360 °C and becomes constant at a temperature of 400 °C. At a temperature of 580 °C, the water production starts to decrease slightly. Initially the number average molecular weight of the pyrolysis oil increases at increasing temperatures, which is ascribed to the observed increase in concentration of water insoluble compound in the pyrolysis oil. At a temperature of 580 °C, the number average molecular weight, viscosity, and the amount of produced water insoluble compounds decreases. The oil obtained at a pyrolysis temperature of 360 °C produced less char, 2 versus 5 wt %, compared to the oil obtained at a pyrolysis temperature of 530 °C in our atomizer/gasifier. About 100% of the carbon goes to the gas phase compared to 84% for the oil obtained at a pyrolysis temperature of 530 °C. Therefore, the 360 °C oil has a better quality for this unit under the applied conditions (850 °C and droplet sizes of 50± μm) Testing the three pyrolysis oils (pyrolysis temperatures of 330, 530, and 580 °C) in the hydrodeoxygenation unit showed that pyrolysis oil with a lower viscosity resulted in deoxygenated oil of lower viscosity. The oxygen content of the three oils was almost the same, but the yield of the deoxygenated oils obtained at a pyrolysis temperature of 330 °C was significantly lower. Together with chemical and physical analyzes of the pyrolysis oils, feeding the pyrolysis oil into a test units relevant for applications, direct information on the effect of varied pyrolysis process parameters on the quality and applicability of the pyrolysis oil is obtained. Note de contenu : Bibiogra. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900885c

Staged catalytic gasification/steam reforming of pyrolysis oil / Guus van Rossum in Industrial & engineering chemistry research, Vol. 48 N° 12 (Juin 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 12 (Juin 2009) . - pp. 5857–5866 Titre : Staged catalytic gasification/steam reforming of pyrolysis oil Type de document : texte imprimé Auteurs : Guus van Rossum, Auteur ; Sascha R. A. Kersten, Auteur ; Wim P.M. van Swaaij, Auteur Année de publication : 2009 Article en page(s) : pp. 5857–5866 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Gasification/steam  reforming  Pyrolysis  oil¨Staged  reactor  MethaneC2−C3  free  syngas Résumé : Gasification/steam reforming of pyrolysis oil was studied in a staged reactor concept, which consisted of an inert fluidized bed and a catalytic fixed bed. Methane and C2−C3 free syngas is produced at a single temperature around 800 °C at atmospheric pressure. By lowering the temperature of the fluidized bed (432−500 °C), its function is changed from a gasifier to an evaporator, and in this way the subsequent catalyst bed actually sees vaporized pyrolysis oil compounds (instead of a fuel gas), which it can more readily convert to syngas. However, the temperature of the fixed bed cannot be too low (min 700 °C) to avoid excessive carbon deposition. System calculations show that when pressurized (30 bar) pyrolysis oil gasification/reforming is considered, the catalytic exit bed temperature should be high (900−1000 °C) to reach sufficient enough methane conversion when syngas is the desired product. When only steam is added at elevated pressure, the H2/CO ratio readily increases, which is desired for hydrogen production. For other applications (e.g., Fischer−Tropsch), carbon dioxide probably has to be recycled to keep the H2/CO ratio around 2−3. The lower heating value efficiency of pyrolysis oil gasification/reforming is comparable to the lower end of the reported range of commercial methane steam reforming. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900194j [article] Staged catalytic gasification/steam reforming of pyrolysis oil [texte imprimé] / Guus van Rossum, Auteur ; Sascha R. A. Kersten, Auteur ; Wim P.M. van Swaaij, Auteur . - 2009 . - pp. 5857–5866. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 12 (Juin 2009) . - pp. 5857–5866 Mots-clés : Gasification/steam  reforming  Pyrolysis  oil¨Staged  reactor  MethaneC2−C3  free  syngas Résumé : Gasification/steam reforming of pyrolysis oil was studied in a staged reactor concept, which consisted of an inert fluidized bed and a catalytic fixed bed. Methane and C2−C3 free syngas is produced at a single temperature around 800 °C at atmospheric pressure. By lowering the temperature of the fluidized bed (432−500 °C), its function is changed from a gasifier to an evaporator, and in this way the subsequent catalyst bed actually sees vaporized pyrolysis oil compounds (instead of a fuel gas), which it can more readily convert to syngas. However, the temperature of the fixed bed cannot be too low (min 700 °C) to avoid excessive carbon deposition. System calculations show that when pressurized (30 bar) pyrolysis oil gasification/reforming is considered, the catalytic exit bed temperature should be high (900−1000 °C) to reach sufficient enough methane conversion when syngas is the desired product. When only steam is added at elevated pressure, the H2/CO ratio readily increases, which is desired for hydrogen production. For other applications (e.g., Fischer−Tropsch), carbon dioxide probably has to be recycled to keep the H2/CO ratio around 2−3. The lower heating value efficiency of pyrolysis oil gasification/reforming is comparable to the lower end of the reported range of commercial methane steam reforming. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900194j