The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Piero Salatino - One of the best experts on this subject based on the ideXlab platform.
-
Oxidative Pyrolysis of solid fuels
Journal of Analytical and Applied Pyrolysis, 2004Co-Authors: Osvalda Senneca, Riccardo Chirone, Piero SalatinoAbstract:Abstract This study addresses the dependence of the rate and pattern of Pyrolysis of solid fuels from the oxidizing versus inert nature of the gaseous atmosphere. A selection of four solid fuels is considered in the study, namely two plastics (polyethylene and polyethylene terephthalate), one lignocellulosic material (Robinia Pseudoacacia) and a South African bituminous coal. Fuels are pyrolyzed in a thermogravimetric apparatus at different heating rates, under inert conditions or in the presence of oxygen at different concentration. Results indicate that the action exerted by oxygen during Pyrolysis depends on the nature of the fuel and on the process conditions such as heating rate and oxygen concentration. Larger heating rates and larger oxygen concentration may indeed emphasize differences between inert and Oxidative Pyrolysis. Further analysis is directed to check the adequacy of a power low kinetic expression to describe the dependence of the rate of Oxidative Pyrolysis from the level of oxygen concentration.
-
a thermogravimetric study of nonfossil solid fuels 2 Oxidative Pyrolysis and char combustion
Energy & Fuels, 2002Co-Authors: Osvalda Senneca, Riccardo Chirone, Piero SalatinoAbstract:The study addresses the competition between the course of purely pyrolytic processes and heterogeneous oxidation during Oxidative Pyrolysis of nonconventional fuels. This feature is one key, together with volatile matter flammability and effectiveness of oxygen transport to the particle, to establish whether flaming or glowing ignition of the fuel takes place. A selection of six nonconventional high volatile solid fuels is considered in the study, namely two plastics (polyethylene and poly(ethylene terephthalate)), two lignocellulosic materials (Robinia Pseudoacacia and waste wood), and two rubber-derived materials (scrap tires and ebonite). The analysis is based on the comparison of the behavior of fuels when heated in a thermogravimetric apparatus under inert and oxidizing atmospheres. Further analysis is directed to assess the heterogeneous combustion kinetics of chars obtained by pre-pyrolyzing in inert conditions samples of the fuels. The study is complementary to a companion paper (Senneca, O.; Chir...
-
A thermogravimetric study of nonfossil solid fuels. 2. Oxidative Pyrolysis and char combustion
'American Chemical Society (ACS)', 2002Co-Authors: Osvalda Senneca, Riccardo Chirone, Piero SalatinoAbstract:The study addresses the competition between the course of purely pyrolytic processes and heterogeneous oxidation during Oxidative Pyrolysis of nonconventional fuels. This feature is one key, together with volatile matter flammability and effectiveness of oxygen transport to the particle, to establish whether flaming or glowing ignition of the fuel takes place. A selection of six nonconventional high volatile solid fuels is considered in the study, namely two plastics (polyethylene and poly(ethylene terephthalate)), two lignocellulosic materials (Robinia Pseudoacacia and waste wood), and two rubber-derived materials (scrap tires and ebonite). The analysis is based on the comparison of the behavior of fuels when heated in a thermogravimetric apparatus under inert and oxidizing atmospheres. Further analysis is directed to assess the heterogeneous combustion kinetics of chars obtained by pre-pyrolyzing in inert conditions samples of the fuels. The study is complementary to a companion paper (Senneca, O.; Chirone, R.; Masi, S.; Salatino, P. A Energy Fuels 2002, 16, 653) where Pyrolysis in nitrogen of the same fuels has been addressed. Results indicate that heterogeneous oxidation and pyrolytic processes play different roles depending on the nature of the fuel. A general feature of all fuels tested is that burnoff cannot be simply described as sequential reaction paths corresponding to purely thermal degradation and heterogeneous oxidation. Synergistic effects between these processes are significant and need to be taken into account
Osvalda Senneca - One of the best experts on this subject based on the ideXlab platform.
-
Oxidative Pyrolysis of solid fuels
Journal of Analytical and Applied Pyrolysis, 2004Co-Authors: Osvalda Senneca, Riccardo Chirone, Piero SalatinoAbstract:Abstract This study addresses the dependence of the rate and pattern of Pyrolysis of solid fuels from the oxidizing versus inert nature of the gaseous atmosphere. A selection of four solid fuels is considered in the study, namely two plastics (polyethylene and polyethylene terephthalate), one lignocellulosic material (Robinia Pseudoacacia) and a South African bituminous coal. Fuels are pyrolyzed in a thermogravimetric apparatus at different heating rates, under inert conditions or in the presence of oxygen at different concentration. Results indicate that the action exerted by oxygen during Pyrolysis depends on the nature of the fuel and on the process conditions such as heating rate and oxygen concentration. Larger heating rates and larger oxygen concentration may indeed emphasize differences between inert and Oxidative Pyrolysis. Further analysis is directed to check the adequacy of a power low kinetic expression to describe the dependence of the rate of Oxidative Pyrolysis from the level of oxygen concentration.
-
a thermogravimetric study of nonfossil solid fuels 2 Oxidative Pyrolysis and char combustion
Energy & Fuels, 2002Co-Authors: Osvalda Senneca, Riccardo Chirone, Piero SalatinoAbstract:The study addresses the competition between the course of purely pyrolytic processes and heterogeneous oxidation during Oxidative Pyrolysis of nonconventional fuels. This feature is one key, together with volatile matter flammability and effectiveness of oxygen transport to the particle, to establish whether flaming or glowing ignition of the fuel takes place. A selection of six nonconventional high volatile solid fuels is considered in the study, namely two plastics (polyethylene and poly(ethylene terephthalate)), two lignocellulosic materials (Robinia Pseudoacacia and waste wood), and two rubber-derived materials (scrap tires and ebonite). The analysis is based on the comparison of the behavior of fuels when heated in a thermogravimetric apparatus under inert and oxidizing atmospheres. Further analysis is directed to assess the heterogeneous combustion kinetics of chars obtained by pre-pyrolyzing in inert conditions samples of the fuels. The study is complementary to a companion paper (Senneca, O.; Chir...
-
A thermogravimetric study of nonfossil solid fuels. 2. Oxidative Pyrolysis and char combustion
'American Chemical Society (ACS)', 2002Co-Authors: Osvalda Senneca, Riccardo Chirone, Piero SalatinoAbstract:The study addresses the competition between the course of purely pyrolytic processes and heterogeneous oxidation during Oxidative Pyrolysis of nonconventional fuels. This feature is one key, together with volatile matter flammability and effectiveness of oxygen transport to the particle, to establish whether flaming or glowing ignition of the fuel takes place. A selection of six nonconventional high volatile solid fuels is considered in the study, namely two plastics (polyethylene and poly(ethylene terephthalate)), two lignocellulosic materials (Robinia Pseudoacacia and waste wood), and two rubber-derived materials (scrap tires and ebonite). The analysis is based on the comparison of the behavior of fuels when heated in a thermogravimetric apparatus under inert and oxidizing atmospheres. Further analysis is directed to assess the heterogeneous combustion kinetics of chars obtained by pre-pyrolyzing in inert conditions samples of the fuels. The study is complementary to a companion paper (Senneca, O.; Chirone, R.; Masi, S.; Salatino, P. A Energy Fuels 2002, 16, 653) where Pyrolysis in nitrogen of the same fuels has been addressed. Results indicate that heterogeneous oxidation and pyrolytic processes play different roles depending on the nature of the fuel. A general feature of all fuels tested is that burnoff cannot be simply described as sequential reaction paths corresponding to purely thermal degradation and heterogeneous oxidation. Synergistic effects between these processes are significant and need to be taken into account
Sylvain Salvador - One of the best experts on this subject based on the ideXlab platform.
-
Oxidative Pyrolysis of pine wood, wheat straw and miscanthus pellets in a fixed bed
Fuel Processing Technology, 2018Co-Authors: Xuan-huynh Pham, Bruno Piriou, Sylvain Salvador, Jeremy Valette, Laurent Van De SteeneAbstract:Oxidative Pyrolysis is a key step in the autothermal operation of many fixed-bed reactors for staged gasification and advanced carbonisation. In these reactors, biomass is converted into charcoal, condensates and permanent gases inside a moving Oxidation Zone (OZ) which also produces energy to self-sustain the process. Oxidative Pyrolysis of three different biomass types: pine wood, miscanthus and wheat straw pellets, was performed in a batch 20 cm diameter fixed bed reactor. Results showed that the OZ consumed 11% to 14% of the stoichiometric air to self-sustain the process and reached a peak temperature around 720 °C whatever the biomass. The propagation velocity and thickness of the OZ were inversely proportional to the ash content and to the bulk density of the biomass. Ash was also shown to influence the yield and composition of the resulting products due to a catalytic effect on primary and secondary Pyrolysis reactions.
-
Oxidative Pyrolysis of Various Biomass in a Fixed Bed: Yields, Composition and Properties of the Products
2018Co-Authors: Xuan-huynh Pham, Bruno Piriou, Sylvain Salvador, Jeremy Valette, Laurent Van De SteeneAbstract:Oxidative Pyrolysis is an effective way for the autothermal operation of staged gasification and carbonization processes. The aim of this work was to investigate the influence of biomass properties on yields, and composition of the products: char, condensates and permanent gases. Oxidative Pyrolysis of three biomasses -Pine, Miscanthus and Wheat straw- were performed in a fixed bed reactor. The mass and energy distribution in the products were established and compared. Char yields were measured to 19%, 25% and 27% for Pine, Miscanthus and Wheat straw pellets, respectively. Temperatures along the bed were measured to be lower than 750°C. The ER was found to be in range of 11 to 14% for the three biomass cases, and about 79% of the energy content in the biomass is converted into the Pyrolysis products. The results highlight the important role of biomass properties, especially ash content, on the Oxidative Pyrolysis.
-
Oxidative Pyrolysis of Agricultural Residues in Gasification and Carbonization Processes
2018Co-Authors: Xuan-huynh Pham, Laurent Van De Steene, Bruno Piriou, Sylvain SalvadorAbstract:Oxidative Pyrolysis, in which heat is provided by the partial oxidation, occurs in many fixed bed reactors of air staged gasification and advanced carbonization processes. In these reactors, an Oxidation Zone (OZ) propagates and separates the virgin biomass from the produced char, and self-sustains the process. To investigate the energy transfer efficiency and to characterize the OZ features, Oxidative Pyrolysis was performed in a 20 cm diameter fixed bed reactor with Wheat straw pellets. Temperatures and biomass bed height were measured continuously during the experiment. The OZ propagated at 0.41 cm/min and consumed about 11 % of the biomass. The role of bed compaction on the effective propagation velocity was highlighted. Char yield was measured to 28.6 % and char accounted for 39.56 % of the total energy content of the Wheat straw. Maximum temperature in the bed reached 780°C. This paper proposes a new insight into the OZ features when it propagates in a biomass fixed bed.
-
Oxidative Pyrolysis of wood chips and of wood pellets in a downdraft continuous fixed bed reactor
Fuel, 2017Co-Authors: Elias Daouk, Jeremy Valette, Laurent Steene, Frederic Paviet, Éric Martin, Sylvain SalvadorAbstract:In air staged gasification and advanced carbonization processes, Oxidative Pyrolysis occurs in downdraft continuous fixed bed reactors. An oxidation zone separates the virgin fuel from the resulting char and propagates upward. Here, the oxidation zone was stabilized at a fixed elevation in a 20 cm I.D. fixed bed reactor using wood chips or wood pellets. In controlled continuous operating mode, we investigated the impact of air flux and bed bulk density on the behavior of the oxidation zone in terms of wood consumption, and yields of chit., gas and tars. An air:wood mass ratio of 0.7 was measured and in our operating conditions, and was not sensitive to air mass flux and bed density. With Oxidative Pyrolysis, yields of organic condensates were lower than with allothermal Pyrolysis, whereas the production of Pyrolysis water and permanent gases increased. Finally, the oxidation zone was shown to be flat and horizontal in a wood pellet bed but inclined in a wood chip bed.
-
Oxidative Pyrolysis of a Large Wood Particle: Effects of Oxygen Concentration and of Particle Size
2014Co-Authors: Elias Daouk, Laurent Steene, Frederic Paviet, Sylvain SalvadorAbstract:In this study, the Oxidative Pyrolysis of large pine wood particles was analysed using a Macro-ThermoGravimetric apparatus (Macro-TGA). The effects of the concentration of oxygen in the surrounding gas and of particle size were investigated. Three different oxygen concentrations (0 %, 10 % and 20 %) and three sizes of cylindrical pine wood samples (4 mm, 8 mm and 12 mm in diameter) were tested at a heating rate of 20 degrees C/min. The results showed that oxygen had a strong influence on Pyrolysis behaviour. We observed that the peak of wood Pyrolysis was higher and appeared at a lower temperature with an increase in the oxygen concentration. When the size of the particle was increased, there was a short delay in DTG curve. But generally speaking, particle size had no significant influence on Oxidative Pyrolysis at this low heating rate. With the 4 mm diameter particles and at a heating rate of 20 degrees C/min, degradation behaviours (TG and DTG curves) were similar and resembled intrinsic degradation behaviours: heat and mass transfer phenomena did not limit the process.
Riccardo Chirone - One of the best experts on this subject based on the ideXlab platform.
-
Oxidative Pyrolysis of solid fuels
Journal of Analytical and Applied Pyrolysis, 2004Co-Authors: Osvalda Senneca, Riccardo Chirone, Piero SalatinoAbstract:Abstract This study addresses the dependence of the rate and pattern of Pyrolysis of solid fuels from the oxidizing versus inert nature of the gaseous atmosphere. A selection of four solid fuels is considered in the study, namely two plastics (polyethylene and polyethylene terephthalate), one lignocellulosic material (Robinia Pseudoacacia) and a South African bituminous coal. Fuels are pyrolyzed in a thermogravimetric apparatus at different heating rates, under inert conditions or in the presence of oxygen at different concentration. Results indicate that the action exerted by oxygen during Pyrolysis depends on the nature of the fuel and on the process conditions such as heating rate and oxygen concentration. Larger heating rates and larger oxygen concentration may indeed emphasize differences between inert and Oxidative Pyrolysis. Further analysis is directed to check the adequacy of a power low kinetic expression to describe the dependence of the rate of Oxidative Pyrolysis from the level of oxygen concentration.
-
a thermogravimetric study of nonfossil solid fuels 2 Oxidative Pyrolysis and char combustion
Energy & Fuels, 2002Co-Authors: Osvalda Senneca, Riccardo Chirone, Piero SalatinoAbstract:The study addresses the competition between the course of purely pyrolytic processes and heterogeneous oxidation during Oxidative Pyrolysis of nonconventional fuels. This feature is one key, together with volatile matter flammability and effectiveness of oxygen transport to the particle, to establish whether flaming or glowing ignition of the fuel takes place. A selection of six nonconventional high volatile solid fuels is considered in the study, namely two plastics (polyethylene and poly(ethylene terephthalate)), two lignocellulosic materials (Robinia Pseudoacacia and waste wood), and two rubber-derived materials (scrap tires and ebonite). The analysis is based on the comparison of the behavior of fuels when heated in a thermogravimetric apparatus under inert and oxidizing atmospheres. Further analysis is directed to assess the heterogeneous combustion kinetics of chars obtained by pre-pyrolyzing in inert conditions samples of the fuels. The study is complementary to a companion paper (Senneca, O.; Chir...
-
A thermogravimetric study of nonfossil solid fuels. 2. Oxidative Pyrolysis and char combustion
'American Chemical Society (ACS)', 2002Co-Authors: Osvalda Senneca, Riccardo Chirone, Piero SalatinoAbstract:The study addresses the competition between the course of purely pyrolytic processes and heterogeneous oxidation during Oxidative Pyrolysis of nonconventional fuels. This feature is one key, together with volatile matter flammability and effectiveness of oxygen transport to the particle, to establish whether flaming or glowing ignition of the fuel takes place. A selection of six nonconventional high volatile solid fuels is considered in the study, namely two plastics (polyethylene and poly(ethylene terephthalate)), two lignocellulosic materials (Robinia Pseudoacacia and waste wood), and two rubber-derived materials (scrap tires and ebonite). The analysis is based on the comparison of the behavior of fuels when heated in a thermogravimetric apparatus under inert and oxidizing atmospheres. Further analysis is directed to assess the heterogeneous combustion kinetics of chars obtained by pre-pyrolyzing in inert conditions samples of the fuels. The study is complementary to a companion paper (Senneca, O.; Chirone, R.; Masi, S.; Salatino, P. A Energy Fuels 2002, 16, 653) where Pyrolysis in nitrogen of the same fuels has been addressed. Results indicate that heterogeneous oxidation and pyrolytic processes play different roles depending on the nature of the fuel. A general feature of all fuels tested is that burnoff cannot be simply described as sequential reaction paths corresponding to purely thermal degradation and heterogeneous oxidation. Synergistic effects between these processes are significant and need to be taken into account
T Hernandezselva - One of the best experts on this subject based on the ideXlab platform.
-
study of the Oxidative Pyrolysis of tobacco sorbitol saccharose mixtures in the presence of mcm 41
Thermochimica Acta, 2012Co-Authors: Amparo Gomezsiurana, Antonio Marcilla, M I Beltran, I Martinez, D Berenguer, R Garciamartinez, T HernandezselvaAbstract:Abstract In this work, the Oxidative Pyrolysis of a reference tobacco and of two ingredients widely used as cigarette ingredients, i.e.: sorbitol and saccharose, as well as that of the mixtures of these materials has been studied by thermogravimetric analysis. The comparison of the results obtained with these corresponding to the Pyrolysis processes under inert atmosphere shows the existence of reaction steps corresponding to pure Pyrolysis or cracking processes and others corresponding to the combustion or other Oxidative processes. The presence of mesoporous MCM-41 as catalyst seems to have more significant influence on the non-Oxidative Pyrolysis stages. Moreover, the Pyrolysis processes taking place at temperatures lower than 400 °C seem to be practically independent of the Oxidative character of the atmosphere used.
