Documents disponibles écrits par cet auteur

Structural changes of sewage sludge char during fixed-bed pyrolysis / Javier Ábrego in Industrial & engineering chemistry research, Vol. 48 N° 6 (Mars 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3211–3221 Titre : Structural changes of sewage sludge char during fixed-bed pyrolysis Type de document : texte imprimé Auteurs : Javier Ábrego, Auteur ; Jesús Arauzo, Auteur ; José Luis Sanchez, Auteur Année de publication : 2009 Article en page(s) : pp. 3211–3221 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Wastewater  treatment  plant  Sewage  sludge  Fixed-bed  reactor  Heating  rate Résumé : Undigested dried sewage sludge from a wastewater treatment plant was pyrolyzed at temperatures between 300 and 900 °C, with an additional hold time at the highest temperature. A fixed-bed reactor was used with a heating rate of 20 °C/min under an atmosphere of nitrogen. Pyrolysis product distribution, FTIR, XRD, BET, SEM, and ultimate and proximate analyses were used to gain a better understanding of the structural changes occurring during pyrolysis. At low to medium pyrolysis temperatures, major mass loss occurs, and most of the gaseous and liquid products are released with little porous development, whereas at temperatures between 700 and 900 °C, structural changes seem to be triggered by calcium carbonate decomposition. This leads to a second stage of gas evolution, as CaO promotes gasification of the char in the presence of iron sulfides. The subsequent release of CO runs parallel with an increase in the BET surface area. In addition, the aromatic character of the char increases with temperature, and nanotube-like tubular structures can be detected by SEM. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801366t [article] Structural changes of sewage sludge char during fixed-bed pyrolysis [texte imprimé] / Javier Ábrego, Auteur ; Jesús Arauzo, Auteur ; José Luis Sanchez, Auteur . - 2009 . - pp. 3211–3221. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3211–3221 Mots-clés : Wastewater  treatment  plant  Sewage  sludge  Fixed-bed  reactor  Heating  rate Résumé : Undigested dried sewage sludge from a wastewater treatment plant was pyrolyzed at temperatures between 300 and 900 °C, with an additional hold time at the highest temperature. A fixed-bed reactor was used with a heating rate of 20 °C/min under an atmosphere of nitrogen. Pyrolysis product distribution, FTIR, XRD, BET, SEM, and ultimate and proximate analyses were used to gain a better understanding of the structural changes occurring during pyrolysis. At low to medium pyrolysis temperatures, major mass loss occurs, and most of the gaseous and liquid products are released with little porous development, whereas at temperatures between 700 and 900 °C, structural changes seem to be triggered by calcium carbonate decomposition. This leads to a second stage of gas evolution, as CaO promotes gasification of the char in the presence of iron sulfides. The subsequent release of CO runs parallel with an increase in the BET surface area. In addition, the aromatic character of the char increases with temperature, and nanotube-like tubular structures can be detected by SEM. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801366t

Water cleaning of biodiesel. effect of catalyst concentration, water amount, and washing temperature on biodiesel obtained from rapeseed oil and used oil / Alberto Gonzalo in Industrial & engineering chemistry research, Vol. 49 N° 9 (Mai 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp. 4436–4443 Titre : Water cleaning of biodiesel. effect of catalyst concentration, water amount, and washing temperature on biodiesel obtained from rapeseed oil and used oil Type de document : texte imprimé Auteurs : Alberto Gonzalo, Auteur ; Manuel García, Auteur ; José Luis Sanchez, Auteur Année de publication : 2010 Article en page(s) : pp. 4436–4443 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biodiesel  Catalyst Résumé : The effect of changing the NaOH wt % (0.7−0.9%) in the transesterification, the amount of water (30−90 wt % of the biodiesel), and the temperature (40−60 °C) in the water cleaning step of biodiesel has been investigated, specifically the influence of these factors on some properties (acidity, viscosity and density) and contaminants (methanol, Na, glycerine, water, and glycerides) of the resulting biodiesel produced from two different oils (rapeseed and used frying oil) using a three factor-two level experimental design, and statistical analysis by ANOVA of the results. The biodiesels produced from both oils show very similar trends: methanol, sodium, and glycerine are almost completely removed from the biodiesel phase in one single step, whereas the glycerides content is not affected by the washing conditions. Viscosity and density are only very slightly affected by the washing step. The water content of the biodiesel is affected by both the water amount used and the temperature in an inverse way: the higher the temperature and the lower the water amount used in the cleaning step, the higher the water content in biodiesel. This washing step was also simulated in Aspen HYSYS V7.0 software. Using the NRTL thermodynamic package for properties calculation, the results obtained showed a reasonable agreement with experimental ones, although it should be improved for a better calculation of biodiesel final properties. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901707q [article] Water cleaning of biodiesel. effect of catalyst concentration, water amount, and washing temperature on biodiesel obtained from rapeseed oil and used oil [texte imprimé] / Alberto Gonzalo, Auteur ; Manuel García, Auteur ; José Luis Sanchez, Auteur . - 2010 . - pp. 4436–4443. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp. 4436–4443 Mots-clés : Biodiesel  Catalyst Résumé : The effect of changing the NaOH wt % (0.7−0.9%) in the transesterification, the amount of water (30−90 wt % of the biodiesel), and the temperature (40−60 °C) in the water cleaning step of biodiesel has been investigated, specifically the influence of these factors on some properties (acidity, viscosity and density) and contaminants (methanol, Na, glycerine, water, and glycerides) of the resulting biodiesel produced from two different oils (rapeseed and used frying oil) using a three factor-two level experimental design, and statistical analysis by ANOVA of the results. The biodiesels produced from both oils show very similar trends: methanol, sodium, and glycerine are almost completely removed from the biodiesel phase in one single step, whereas the glycerides content is not affected by the washing conditions. Viscosity and density are only very slightly affected by the washing step. The water content of the biodiesel is affected by both the water amount used and the temperature in an inverse way: the higher the temperature and the lower the water amount used in the cleaning step, the higher the water content in biodiesel. This washing step was also simulated in Aspen HYSYS V7.0 software. Using the NRTL thermodynamic package for properties calculation, the results obtained showed a reasonable agreement with experimental ones, although it should be improved for a better calculation of biodiesel final properties. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901707q