Documents disponibles écrits par cet auteur

Combustion of Single Coal Char Particles under Fluidized Bed Oxyfiring Conditions / Fabrizio Scala in Industrial & engineering chemistry research, Vol. 49 N° 21 (Novembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 11029-11036 Titre : Combustion of Single Coal Char Particles under Fluidized Bed Oxyfiring Conditions Type de document : texte imprimé Auteurs : Fabrizio Scala, Auteur ; Riccardo Chirone, Auteur Année de publication : 2011 Article en page(s) : pp. 11029-11036 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fluidized  bed  Fluidization  Coal  Combustion Résumé : The fluidized bed combustion of single coal char particles was investigated at high CO2 concentrations, typical of oxyfiring conditions, at different bed temperatures and oxygen concentrations. The conversion rate of the char particles was followed as a function of time by continuously measuring the outlet CO and O2 concentrations. Char gasification tests were also carried out under 100% CO2 at different temperatures to quantify the importance of this reaction and to extract a suitable kinetic expression. This expression was then combined with a correlation for the mass transfer controlled particle burning rate to simulate the experimental conversion rate data. The calculated carbon consumption rate was an excellent fit to the experimental data for all the operating conditions. Results showed that carbon combustion dominates particle conversion at high oxygen concentrations and low temperatures, while carbon gasification contributes to a comparable extent at high temperatures and low oxygen concentrations. Even under fluidized bed oxyfiring conditions oxygen boundary layer diffusion controls the combustion rate, and the main combustion product is CO2 rather than CO. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23447998 [article] Combustion of Single Coal Char Particles under Fluidized Bed Oxyfiring Conditions [texte imprimé] / Fabrizio Scala, Auteur ; Riccardo Chirone, Auteur . - 2011 . - pp. 11029-11036. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 11029-11036 Mots-clés : Fluidized  bed  Fluidization  Coal  Combustion Résumé : The fluidized bed combustion of single coal char particles was investigated at high CO2 concentrations, typical of oxyfiring conditions, at different bed temperatures and oxygen concentrations. The conversion rate of the char particles was followed as a function of time by continuously measuring the outlet CO and O2 concentrations. Char gasification tests were also carried out under 100% CO2 at different temperatures to quantify the importance of this reaction and to extract a suitable kinetic expression. This expression was then combined with a correlation for the mass transfer controlled particle burning rate to simulate the experimental conversion rate data. The calculated carbon consumption rate was an excellent fit to the experimental data for all the operating conditions. Results showed that carbon combustion dominates particle conversion at high oxygen concentrations and low temperatures, while carbon gasification contributes to a comparable extent at high temperatures and low oxygen concentrations. Even under fluidized bed oxyfiring conditions oxygen boundary layer diffusion controls the combustion rate, and the main combustion product is CO2 rather than CO. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23447998

A Population balance model on sorbent in CFB combustors / Fabio Montagnaro in Industrial & engineering chemistry research, Vol. 50 N° 16 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 16 (Août 2011) . - pp. 9704-9711 Titre : A Population balance model on sorbent in CFB combustors : the influence of particle attrition Type de document : texte imprimé Auteurs : Fabio Montagnaro, Auteur ; Piero Salatino, Auteur ; Fabrizio Scala, Auteur Année de publication : 2011 Article en page(s) : pp. 9704-9711 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Attrition  Modeling  Population  balance Résumé : A population balance model on sorbent particles in an atmospheric circulating fluidized bed combustor fueled with sulfur-bearing solid fuel is developed. The model aims at the prediction of the following quantities establishing at the steady state in the combustor: sorbent inventory and particle size distribution, partitioning of the sorbent between fly and bottom ash, desulfurization efficiency, and the mass flow rate of the sorbent circulating around the loop of the combustor. The core of the model is represented by the population balance equations on sorbent particles, which embody terms expressing the rate of sorbent attrition/fragmentation. The effect of the progress of sulfation on attrition is taken into account by the selection of appropriate constitutive equations. Model results are presented and discussed with the aim of clarifying the influence of particle attrition. In particular, the effect of attrition on bed sorbent partitioning between lime and sulfated lime and on SO2 capture efficiency is highlighted. The model enables one to assess the balance between opposed effects of attrition on desulfurization: on one hand, attrited fines are characterized by a better reactivity with respect to SO2, when compared with the mother particles; on the other hand, attrition is responsible for larger amounts of unsulfated material reporting to the fly ash. A sensitivity analysis is also carried out with reference to relevant operational parameters of the combustor in order to correlate changes in ash partitioning and desulfurization efficiency with the extent of sorbent attrition and solids circulation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24425214 [article] A Population balance model on sorbent in CFB combustors : the influence of particle attrition [texte imprimé] / Fabio Montagnaro, Auteur ; Piero Salatino, Auteur ; Fabrizio Scala, Auteur . - 2011 . - pp. 9704-9711. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 16 (Août 2011) . - pp. 9704-9711 Mots-clés : Attrition  Modeling  Population  balance Résumé : A population balance model on sorbent particles in an atmospheric circulating fluidized bed combustor fueled with sulfur-bearing solid fuel is developed. The model aims at the prediction of the following quantities establishing at the steady state in the combustor: sorbent inventory and particle size distribution, partitioning of the sorbent between fly and bottom ash, desulfurization efficiency, and the mass flow rate of the sorbent circulating around the loop of the combustor. The core of the model is represented by the population balance equations on sorbent particles, which embody terms expressing the rate of sorbent attrition/fragmentation. The effect of the progress of sulfation on attrition is taken into account by the selection of appropriate constitutive equations. Model results are presented and discussed with the aim of clarifying the influence of particle attrition. In particular, the effect of attrition on bed sorbent partitioning between lime and sulfated lime and on SO2 capture efficiency is highlighted. The model enables one to assess the balance between opposed effects of attrition on desulfurization: on one hand, attrited fines are characterized by a better reactivity with respect to SO2, when compared with the mother particles; on the other hand, attrition is responsible for larger amounts of unsulfated material reporting to the fly ash. A sensitivity analysis is also carried out with reference to relevant operational parameters of the combustor in order to correlate changes in ash partitioning and desulfurization efficiency with the extent of sorbent attrition and solids circulation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24425214