2009
Artículos de revista
Giménez-López, Jorge; Rasmussen, Christian Lund; Alzueta, María U; Gao, Yide; Marshall, Paul; Glarborg, Peter
Experimental and kinetic modeling study of C2H4 oxidation at high pressure Artículo de revista
En: Proceedings of the Combustion Institute, vol. 32 I, no 1, pp. 367–375, 2009, ISSN: 15407489.
@article{Lopez2009,
title = {Experimental and kinetic modeling study of C2H4 oxidation at high pressure},
author = {Jorge Giménez-López and Christian Lund Rasmussen and María U Alzueta and Yide Gao and Paul Marshall and Peter Glarborg},
doi = {10.1016/j.proci.2008.06.188},
issn = {15407489},
year = {2009},
date = {2009-01-01},
journal = {Proceedings of the Combustion Institute},
volume = {32 I},
number = {1},
pages = {367--375},
publisher = {Elsevier Ltd},
abstract = {A detailed chemical kinetic model for oxidation of C2H 4 in the intermediate temperature range and high pressure has been developed and validated experimentally. New ab initio calculations and RRKM analysis of the important C2H3 + O2 reaction was used to obtain rate coefficients over a wide range of conditions (0.003-100 bar, 200-3000 K). The results indicate that at 60 bar and medium temperatures vinyl peroxide, rather than CH2O and HCO, is the dominant product. The experiments, involving C2H4/O2 mixtures diluted in N2, were carried out in a high pressure flow reactor at 600-900 K and 60 bar, varying the reaction stoichiometry from very lean to fuel-rich conditions. Model predictions are generally satisfactory. The governing reaction mechanisms are outlined based on calculations with the kinetic model. Under the investigated conditions the oxidation pathways for C2H4 are more complex than those prevailing at higher temperatures and lower pressures. The major differences are the importance of the hydroxyethyl (CH2CH2OH) and 2-hydroperoxyethyl (CH2CH2OOH) radicals, formed from addition of OH and HO2 to C2H4, and vinyl peroxide, formed from C2H3 + O2. Hydroxyethyl is oxidized through the peroxide HOCH2CH2OO (lean conditions) or through ethenol (low O2 concentration), while 2-hydroperoxyethyl is converted through oxirane. textcopyright 2009 The Combustion Institute. Published by Elsevier Inc. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A detailed chemical kinetic model for oxidation of C2H 4 in the intermediate temperature range and high pressure has been developed and validated experimentally. New ab initio calculations and RRKM analysis of the important C2H3 + O2 reaction was used to obtain rate coefficients over a wide range of conditions (0.003-100 bar, 200-3000 K). The results indicate that at 60 bar and medium temperatures vinyl peroxide, rather than CH2O and HCO, is the dominant product. The experiments, involving C2H4/O2 mixtures diluted in N2, were carried out in a high pressure flow reactor at 600-900 K and 60 bar, varying the reaction stoichiometry from very lean to fuel-rich conditions. Model predictions are generally satisfactory. The governing reaction mechanisms are outlined based on calculations with the kinetic model. Under the investigated conditions the oxidation pathways for C2H4 are more complex than those prevailing at higher temperatures and lower pressures. The major differences are the importance of the hydroxyethyl (CH2CH2OH) and 2-hydroperoxyethyl (CH2CH2OOH) radicals, formed from addition of OH and HO2 to C2H4, and vinyl peroxide, formed from C2H3 + O2. Hydroxyethyl is oxidized through the peroxide HOCH2CH2OO (lean conditions) or through ethenol (low O2 concentration), while 2-hydroperoxyethyl is converted through oxirane. textcopyright 2009 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
2008
Artículos de revista
Abián, María; Esarte, Claudia; Millera, Ángela; Bilbao, Rafael; Alzueta, María U
Oxidation of acetylene-ethanol mixtures and their interaction with NO Artículo de revista
En: Energy and Fuels, vol. 22, no 6, pp. 3814–3823, 2008, ISSN: 08870624.
@article{Abian2008,
title = {Oxidation of acetylene-ethanol mixtures and their interaction with NO},
author = {María Abián and Claudia Esarte and Ángela Millera and Rafael Bilbao and María U Alzueta},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ef800550k},
issn = {08870624},
year = {2008},
date = {2008-11-01},
journal = {Energy and Fuels},
volume = {22},
number = {6},
pages = {3814--3823},
publisher = {American Chemical Society},
abstract = {An experimental and theoretical study of the oxidation of acetylene-ethanol mixtures in the absence and presence of NO has been carried out. The experiments were conducted in an isothermal quartz flow reactor at atmospheric pressure in the 775-1375 K temperature range. The influence of the temperature, stoichiometry (by varying the O2 concentration for given C2H2 and C2H5OH initial concentrations), presence of different amounts of ethanol added to acetylene, and presence of NO on the concentrations of C2H2, C2H5OH, CO, CO2, NO, and HCN has been analyzed. The gas-phase kinetic mechanism used for calculations was that developed by Alzueta et al. (Alzueta, M. U.; Borruey, M.; Callejas, A.; Millera, A.; Bilbao, R. Combust. Flame 2008, 152, 377-386) for acetylene conversion, on the basis of a previous work by Skjoth-Rasmussen et al. (Skjøth-Rasmussen, M. S.; Glarborg, P.; Østberg, M.; Johannessen, J. T.; Livbjerg, H.; Jensen, A. D.; Christensen, T. S. Combust. Flame 2004, 136, 91-128), with reactions added from the ethanol oxidation mechanism of Alzueta and Hernández (Alzueta, M. U.; Hernández, J. M. Energy Fuels 2002, 16, 166-171), as well as reactions from the mechanism developed by Glarborg et al. (Glarborg, P.; Alzueta, M. U.; Dam-Johansen, K.; Miller, J. A. Combust. Flame 1998, 115, 1-27) to describe the interactions among C1/C2 hydrocarbons and nitric oxide. The experimental results show that the ethanol presence significantly modifies the acetylene conversion regime, inhibiting soot formation. An increase of the oxygen level and temperature favor acetylene conversion. The presence of NO results in some differences in relation to the oxidation regimes of the acetylene-ethanol blends. The reduction of NO by the mixture is favored at the highest temperatures of the considered range, above 1275 K, and for moderately fuel-ricb conditions ($łambda$ = 0.7). In general, the kinetic model satisfactorily simulates the experimental trends. Model predictions indicate that, under the conditions of this study, HCCO + NO is the most important reaction in reducing NO. Moreover, the ethanol presence slightly inhibits the NO reduction in relation to the oxidation of pure acetylene. textcopyright 2008 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An experimental and theoretical study of the oxidation of acetylene-ethanol mixtures in the absence and presence of NO has been carried out. The experiments were conducted in an isothermal quartz flow reactor at atmospheric pressure in the 775-1375 K temperature range. The influence of the temperature, stoichiometry (by varying the O2 concentration for given C2H2 and C2H5OH initial concentrations), presence of different amounts of ethanol added to acetylene, and presence of NO on the concentrations of C2H2, C2H5OH, CO, CO2, NO, and HCN has been analyzed. The gas-phase kinetic mechanism used for calculations was that developed by Alzueta et al. (Alzueta, M. U.; Borruey, M.; Callejas, A.; Millera, A.; Bilbao, R. Combust. Flame 2008, 152, 377-386) for acetylene conversion, on the basis of a previous work by Skjoth-Rasmussen et al. (Skjøth-Rasmussen, M. S.; Glarborg, P.; Østberg, M.; Johannessen, J. T.; Livbjerg, H.; Jensen, A. D.; Christensen, T. S. Combust. Flame 2004, 136, 91-128), with reactions added from the ethanol oxidation mechanism of Alzueta and Hernández (Alzueta, M. U.; Hernández, J. M. Energy Fuels 2002, 16, 166-171), as well as reactions from the mechanism developed by Glarborg et al. (Glarborg, P.; Alzueta, M. U.; Dam-Johansen, K.; Miller, J. A. Combust. Flame 1998, 115, 1-27) to describe the interactions among C1/C2 hydrocarbons and nitric oxide. The experimental results show that the ethanol presence significantly modifies the acetylene conversion regime, inhibiting soot formation. An increase of the oxygen level and temperature favor acetylene conversion. The presence of NO results in some differences in relation to the oxidation regimes of the acetylene-ethanol blends. The reduction of NO by the mixture is favored at the highest temperatures of the considered range, above 1275 K, and for moderately fuel-ricb conditions ($łambda$ = 0.7). In general, the kinetic model satisfactorily simulates the experimental trends. Model predictions indicate that, under the conditions of this study, HCCO + NO is the most important reaction in reducing NO. Moreover, the ethanol presence slightly inhibits the NO reduction in relation to the oxidation of pure acetylene. textcopyright 2008 American Chemical Society.
Aguiar, Leonardo; Márquez-Montesinos, F; Gonzalo, Alberto; Sánchez, José Luis; Arauzo, Jesús
Influence of temperature and particle size on the fixed bed pyrolysis of orange peel residues Artículo de revista
En: Journal of Analytical and Applied Pyrolysis, vol. 83, no 1, pp. 124–130, 2008, ISSN: 01652370.
@article{Aguiar2008,
title = {Influence of temperature and particle size on the fixed bed pyrolysis of orange peel residues},
author = {Leonardo Aguiar and F Márquez-Montesinos and Alberto Gonzalo and José Luis Sánchez and Jesús Arauzo},
doi = {10.1016/j.jaap.2008.06.009},
issn = {01652370},
year = {2008},
date = {2008-09-01},
journal = {Journal of Analytical and Applied Pyrolysis},
volume = {83},
number = {1},
pages = {124--130},
publisher = {Elsevier},
abstract = {Orange peel is a residue from the production of juice. Its energetic valorisation could be interesting in areas where a different use, such as animal feed, is not possible. In order to investigate the viability of energy recovery, the pyrolysis of orange peel residues was studied in a fixed bed reactor, as an initial assessment of this process. The influence of pyrolysis temperature (300-600 °C) and particle size (dp < 300 $mu$m and dp > 800 $mu$m) on product distribution, gas composition and char heating value has been investigated using a factorial design of experiments. Gas, char and water are the main products obtained; tar is only about 6 wt.% of the initial residue. Temperature was found to be the parameter which exerts a more important influence on the results than particle size. textcopyright 2008 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Orange peel is a residue from the production of juice. Its energetic valorisation could be interesting in areas where a different use, such as animal feed, is not possible. In order to investigate the viability of energy recovery, the pyrolysis of orange peel residues was studied in a fixed bed reactor, as an initial assessment of this process. The influence of pyrolysis temperature (300-600 °C) and particle size (dp < 300 $mu$m and dp > 800 $mu$m) on product distribution, gas composition and char heating value has been investigated using a factorial design of experiments. Gas, char and water are the main products obtained; tar is only about 6 wt.% of the initial residue. Temperature was found to be the parameter which exerts a more important influence on the results than particle size. textcopyright 2008 Elsevier B.V. All rights reserved.
García-Bacaicoa, Pedro; Mastral, José Francisco; Ceamanos, Jesús; Berrueco, César; Serrano, S
Gasification of biomass/high density polyethylene mixtures in a downdraft gasifier Artículo de revista
En: Bioresource Technology, vol. 99, no 13, pp. 5485–5491, 2008, ISSN: 09608524.
@article{Garcia-Bacaicoa2008,
title = {Gasification of biomass/high density polyethylene mixtures in a downdraft gasifier},
author = {Pedro García-Bacaicoa and José Francisco Mastral and Jesús Ceamanos and César Berrueco and S Serrano},
doi = {10.1016/j.biortech.2007.11.003},
issn = {09608524},
year = {2008},
date = {2008-09-01},
journal = {Bioresource Technology},
volume = {99},
number = {13},
pages = {5485--5491},
publisher = {Elsevier},
abstract = {In this work, an experimental study of the thermal decomposition of mixtures of wood particles and high density polyethylene in different atmospheres has been carried out in a downdraft gasifier with a nominal processing capacity of 50 kg/h. The main objective was to study the feasibility of the operation of the gasification plant using mixtures and to investigate the characteristics of the gas obtained. In order to do so, experiments with biomass only and with mixtures with up to 15% HDPE have been carried out. The main components of the gas generated are N2 (50%), H2 (14%), CO (9-22%) and CO2 (7-17%) and its relatively high calorific value was adequate for using it in an internal combustion engine generator consisting of a modified diesel engine coupled with a 25 kV A alternator. textcopyright 2007 Elsevier Ltd. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work, an experimental study of the thermal decomposition of mixtures of wood particles and high density polyethylene in different atmospheres has been carried out in a downdraft gasifier with a nominal processing capacity of 50 kg/h. The main objective was to study the feasibility of the operation of the gasification plant using mixtures and to investigate the characteristics of the gas obtained. In order to do so, experiments with biomass only and with mixtures with up to 15% HDPE have been carried out. The main components of the gas generated are N2 (50%), H2 (14%), CO (9-22%) and CO2 (7-17%) and its relatively high calorific value was adequate for using it in an internal combustion engine generator consisting of a modified diesel engine coupled with a 25 kV A alternator. textcopyright 2007 Elsevier Ltd. All rights reserved.
Fonts, Isabel; Juan, Alfonso; Gea, Gloria; Murillo, María Benita; Sánchez, José Luis
Sewage sludge pyrolysis in fluidized bed, 1: Influence of operational conditions on the product distribution Artículo de revista
En: Industrial and Engineering Chemistry Research, vol. 47, no 15, pp. 5376–5385, 2008, ISSN: 08885885.
@article{Fonts2008,
title = {Sewage sludge pyrolysis in fluidized bed, 1: Influence of operational conditions on the product distribution},
author = {Isabel Fonts and Alfonso Juan and Gloria Gea and María Benita Murillo and José Luis Sánchez},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ie7017788},
issn = {08885885},
year = {2008},
date = {2008-08-01},
journal = {Industrial and Engineering Chemistry Research},
volume = {47},
number = {15},
pages = {5376--5385},
publisher = {American Chemical Society},
abstract = {In this work, pyrolysis of sewage sludge in a fluidized bed was studied experimentally in order to obtain a liquid product able to be used in energetic applications. The influence of operational conditions on the product distribution was studied. The operational variables were as follows: temperature (450-650°C), nitrogen flow rate (3.5-5.5 L(NTP) min-1), and solid feed rate (3.0-6.0 g min-1). Their influence was considered on me yields to the three pyrolysis products: solid, liquid, and gas. The liquid yield was mainly influenced by the bed temperature but also by the nitrogen flow rate and the solid feed rate. The bed temperature and the nitrogen flow rate showed a quadratic effect, and the maximum liquid yield was achieved at around 540°C and around 4.5 L(NTP) min-1 of nitrogen. The solid feed rate just affected on the liquid yield at the lower temperatures studied, and the maximum liquid yield was obtained at the lowest solid feed rates. The design of experiments (DOE) statistical tool was used in me preparation of the work. textcopyright 2008 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work, pyrolysis of sewage sludge in a fluidized bed was studied experimentally in order to obtain a liquid product able to be used in energetic applications. The influence of operational conditions on the product distribution was studied. The operational variables were as follows: temperature (450-650°C), nitrogen flow rate (3.5-5.5 L(NTP) min-1), and solid feed rate (3.0-6.0 g min-1). Their influence was considered on me yields to the three pyrolysis products: solid, liquid, and gas. The liquid yield was mainly influenced by the bed temperature but also by the nitrogen flow rate and the solid feed rate. The bed temperature and the nitrogen flow rate showed a quadratic effect, and the maximum liquid yield was achieved at around 540°C and around 4.5 L(NTP) min-1 of nitrogen. The solid feed rate just affected on the liquid yield at the lower temperatures studied, and the maximum liquid yield was obtained at the lowest solid feed rates. The design of experiments (DOE) statistical tool was used in me preparation of the work. textcopyright 2008 American Chemical Society.
Medrano, José A; Oliva, Miriam; Ruiz, Joaquín; García, Lucía; Arauzo, Jesús
Catalytic steam reforming of acetic acid in a fluidized bed reactor with oxygen addition Artículo de revista
En: International Journal of Hydrogen Energy, vol. 33, no 16, pp. 4387–4396, 2008, ISSN: 03603199.
@article{Medrano2008,
title = {Catalytic steam reforming of acetic acid in a fluidized bed reactor with oxygen addition},
author = {José A Medrano and Miriam Oliva and Joaquín Ruiz and Lucía García and Jesús Arauzo},
doi = {10.1016/j.ijhydene.2008.05.023},
issn = {03603199},
year = {2008},
date = {2008-08-01},
journal = {International Journal of Hydrogen Energy},
volume = {33},
number = {16},
pages = {4387--4396},
publisher = {Pergamon},
abstract = {Catalytic steam reforming of bio-oil is a promising process for producing hydrogen in a sustainable environmentally friendly way that can improve the utilization of local resources (natural sources or wastes). However, there remain drawbacks such as coke formation that produce operational problems and deactivation of the catalysts. Coprecipitated Ni/Al catalysts are here used in a fluidized bed for reforming at 650 °C of acetic acid as a model compound of bio-oil-aqueous fraction. Different strategies are applied in order to study their effects on the catalytic steam reforming process: modification of the catalyst by increasing the calcination temperature or adding promoters such as calcium. The addition of small quantities of oxygen is also tested resulting in an optimum percentage to achieve a high carbon conversion process with less coke and without a hydrogen yield penalty production. The results for catalytic steam reforming are compared with other ones from literature. textcopyright 2008 International Association for Hydrogen Energy.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Catalytic steam reforming of bio-oil is a promising process for producing hydrogen in a sustainable environmentally friendly way that can improve the utilization of local resources (natural sources or wastes). However, there remain drawbacks such as coke formation that produce operational problems and deactivation of the catalysts. Coprecipitated Ni/Al catalysts are here used in a fluidized bed for reforming at 650 °C of acetic acid as a model compound of bio-oil-aqueous fraction. Different strategies are applied in order to study their effects on the catalytic steam reforming process: modification of the catalyst by increasing the calcination temperature or adding promoters such as calcium. The addition of small quantities of oxygen is also tested resulting in an optimum percentage to achieve a high carbon conversion process with less coke and without a hydrogen yield penalty production. The results for catalytic steam reforming are compared with other ones from literature. textcopyright 2008 International Association for Hydrogen Energy.
Aznar, María; Manyà, Joan Josep; García, Gorka; Sánchez, José Luis; Murillo, María Benita
Influence of freeboard temperature, fluidization velocity, and particle size on tar production and composition during the air gasification of sewage sludge Artículo de revista
En: Energy and Fuels, vol. 22, no 4, pp. 2840–2850, 2008, ISSN: 08870624.
@article{Aznar2008,
title = {Influence of freeboard temperature, fluidization velocity, and particle size on tar production and composition during the air gasification of sewage sludge},
author = {María Aznar and Joan Josep Manyà and Gorka García and José Luis Sánchez and María Benita Murillo},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ef800017u},
issn = {08870624},
year = {2008},
date = {2008-07-01},
journal = {Energy and Fuels},
volume = {22},
number = {4},
pages = {2840--2850},
publisher = {American Chemical Society},
abstract = {The influence of freeboard temperature, fluidization velocity, and particle size on tar production and composition during the air gasification of dried sewage sludge has been researched using a bench-scale gasifier. Of the operating variables analyzed, the results obtained from a statistical analysis (ANOVA and PCA) indicate that only the freeboard temperature has a significant influence on tar production. The results also show that freeboard temperature is the key factor that influences the tar composition. A high freeboard temperature reduces the amount of tar produced, but the tar compounds obtained are mainly PAH, which could require a more complicated secondary treatment for tar removal. Nevertheless, an increase in the freeboard temperature value implies a substantial increase in both low heating value and cold gas efficiency (6.5% and 10.8%, respectively, when the required freeboard temperature was increased from 873 to 1123 K). Future studies should focus on testing/developing catalytic materials able to degrade (in a secondary treatment) tar with a high content of PAH compounds. textcopyright 2008 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The influence of freeboard temperature, fluidization velocity, and particle size on tar production and composition during the air gasification of dried sewage sludge has been researched using a bench-scale gasifier. Of the operating variables analyzed, the results obtained from a statistical analysis (ANOVA and PCA) indicate that only the freeboard temperature has a significant influence on tar production. The results also show that freeboard temperature is the key factor that influences the tar composition. A high freeboard temperature reduces the amount of tar produced, but the tar compounds obtained are mainly PAH, which could require a more complicated secondary treatment for tar removal. Nevertheless, an increase in the freeboard temperature value implies a substantial increase in both low heating value and cold gas efficiency (6.5% and 10.8%, respectively, when the required freeboard temperature was increased from 873 to 1123 K). Future studies should focus on testing/developing catalytic materials able to degrade (in a secondary treatment) tar with a high content of PAH compounds. textcopyright 2008 American Chemical Society.
Manyà, Joan Josep; Arauzo, Jesús
An alternative kinetic approach to describe the isothermal pyrolysis of micro-particles of sugar cane bagasse Artículo de revista
En: Chemical Engineering Journal, vol. 139, no 3, pp. 549–561, 2008, ISSN: 13858947.
@article{Manya2008,
title = {An alternative kinetic approach to describe the isothermal pyrolysis of micro-particles of sugar cane bagasse},
author = {Joan Josep Manyà and Jesús Arauzo},
doi = {10.1016/j.cej.2007.09.005},
issn = {13858947},
year = {2008},
date = {2008-06-01},
journal = {Chemical Engineering Journal},
volume = {139},
number = {3},
pages = {549--561},
publisher = {Elsevier},
abstract = {A new kinetic approach is presented for modeling micro-particle pyrolysis of sugar cane bagasse for isothermal conditions. The model is based on a superimposition of kinetics pseudo-components which are based on single-step reactions to model primary pyrolysis. To ensure the validity and reliability of the kinetic parameters, the operating conditions must guarantee the minimisation of heat transfer intrusions and vapour-solid interactions. The kinetic model was previously deduced from thermogravimetric data obtained at 20 K min-1 for the same bagasse samples. The potential effects related to an increase of the heating rate and the mineral matter content were taken into account during the adjustment of the parameters to reproduce the isothermal experiments. A generalised kinetic model proposed by Miller and Bellan [R.S. Miller, J. Bellan, A generalised biomass pyrolysis model based on superimposed cellulose, hemicellulose and lignin kinetics, Combust. Sci. Technol. 126 (1997) 97-137] was selected to compare the degree of agreement between the two models. In spite of the effectiveness of the Miller and Bellan model, a slightly better performance was achieved for the model proposed in this work. The methodology followed in the present study for sugar cane bagasse samples could be useful to predict the isothermal pyrolysis behaviour of arbitrary biomass feedstocks in a relatively easy way. textcopyright 2007 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A new kinetic approach is presented for modeling micro-particle pyrolysis of sugar cane bagasse for isothermal conditions. The model is based on a superimposition of kinetics pseudo-components which are based on single-step reactions to model primary pyrolysis. To ensure the validity and reliability of the kinetic parameters, the operating conditions must guarantee the minimisation of heat transfer intrusions and vapour-solid interactions. The kinetic model was previously deduced from thermogravimetric data obtained at 20 K min-1 for the same bagasse samples. The potential effects related to an increase of the heating rate and the mineral matter content were taken into account during the adjustment of the parameters to reproduce the isothermal experiments. A generalised kinetic model proposed by Miller and Bellan [R.S. Miller, J. Bellan, A generalised biomass pyrolysis model based on superimposed cellulose, hemicellulose and lignin kinetics, Combust. Sci. Technol. 126 (1997) 97-137] was selected to compare the degree of agreement between the two models. In spite of the effectiveness of the Miller and Bellan model, a slightly better performance was achieved for the model proposed in this work. The methodology followed in the present study for sugar cane bagasse samples could be useful to predict the isothermal pyrolysis behaviour of arbitrary biomass feedstocks in a relatively easy way. textcopyright 2007 Elsevier B.V. All rights reserved.
Guerrero, Marta; Ruiz, Pilar M; Millera, Ángela; Alzueta, María U; Bilbao, Rafael
Oxidation kinetics of eucalyptus chars produced at low and high heating rates Artículo de revista
En: Energy and Fuels, vol. 22, no 3, pp. 2084–2090, 2008, ISSN: 08870624.
@article{Guerrero2008b,
title = {Oxidation kinetics of eucalyptus chars produced at low and high heating rates},
author = {Marta Guerrero and Pilar M Ruiz and Ángela Millera and María U Alzueta and Rafael Bilbao},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ef700643p},
issn = {08870624},
year = {2008},
date = {2008-05-01},
journal = {Energy and Fuels},
volume = {22},
number = {3},
pages = {2084--2090},
publisher = {American Chemical Society},
abstract = {An experimental and kinetic study of the oxidation of eucalyptus chars obtained by pyrolysis at 900 °C with low and high heating rates (LHR and HHR, respectively) has been performed. Oxidation experiments were carried out in a quartz reactor with an inlet oxygen concentration ranging from 100 to 1000 ppmv in a nitrogen flow, a temperature of 900 °C, and a flow rate of 1000 mL min-1 (STP). In order to analyze the temperature influence on the process and to obtain the process activation energy, char oxidation tests were also performed in the 650-900 °C temperature range, for a given oxygen concentration of 500 ppmv. Kinetic parameters were derived from the oxidation reaction data, which fitted properly the macroscopic model of type I in regime II. The reaction orders with respect to the oxygen concentration were found to be 0.58 and 0.66 for LHR and HHR chars, respectively. In both cases, it was observed a "break" in the Arrhenius plot. At low temperatures (650-800 °C), the activation energy was similar for the oxidation of both chars, in the 35-45 kJ mol-1 range. However, in the high temperature range (800-900 °C), the activation energy was 100 kJ mol-1 for the LHR char oxidation and 60 kJ mol-1 for the HHR char oxidation. The differences between the oxidative reactivities of the LHR and HHR chars are further discussed in terms of the chemical and physical char properties. textcopyright 2008 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An experimental and kinetic study of the oxidation of eucalyptus chars obtained by pyrolysis at 900 °C with low and high heating rates (LHR and HHR, respectively) has been performed. Oxidation experiments were carried out in a quartz reactor with an inlet oxygen concentration ranging from 100 to 1000 ppmv in a nitrogen flow, a temperature of 900 °C, and a flow rate of 1000 mL min-1 (STP). In order to analyze the temperature influence on the process and to obtain the process activation energy, char oxidation tests were also performed in the 650-900 °C temperature range, for a given oxygen concentration of 500 ppmv. Kinetic parameters were derived from the oxidation reaction data, which fitted properly the macroscopic model of type I in regime II. The reaction orders with respect to the oxygen concentration were found to be 0.58 and 0.66 for LHR and HHR chars, respectively. In both cases, it was observed a “break” in the Arrhenius plot. At low temperatures (650-800 °C), the activation energy was similar for the oxidation of both chars, in the 35-45 kJ mol-1 range. However, in the high temperature range (800-900 °C), the activation energy was 100 kJ mol-1 for the LHR char oxidation and 60 kJ mol-1 for the HHR char oxidation. The differences between the oxidative reactivities of the LHR and HHR chars are further discussed in terms of the chemical and physical char properties. textcopyright 2008 American Chemical Society.
Bona, Sergio; Guillén, Patricia; Alcalde, Germán J; García, Lucía; Bilbao, Rafael
Toluene steam reforming using coprecipitated Ni/Al catalysts modified with lanthanum or cobalt Artículo de revista
En: Chemical Engineering Journal, vol. 137, no 3, pp. 587–597, 2008, ISSN: 13858947.
@article{Bona2008,
title = {Toluene steam reforming using coprecipitated Ni/Al catalysts modified with lanthanum or cobalt},
author = {Sergio Bona and Patricia Guillén and Germán J Alcalde and Lucía García and Rafael Bilbao},
doi = {10.1016/j.cej.2007.05.022},
issn = {13858947},
year = {2008},
date = {2008-04-01},
journal = {Chemical Engineering Journal},
volume = {137},
number = {3},
pages = {587--597},
publisher = {Elsevier},
abstract = {Toluene has been chosen as a model compound of biomass gasification tar and its destruction has been studied by steam reforming. The experiments have been performed in a bench scale installation that uses a fluidized bed reactor with a technology very similar to the Waterloo Fast Pyrolysis Process (WFPP). All the experiments have been carried out at 650 °C and atmospheric pressure. Ni/Al/La catalysts with La/Ni ratios of 0, 0.044, 0.088 and 0.13 have been tested, the middle two showing the best performance. Ni/Co/Al catalysts with Co/Ni ratios of 0, 0.025, 0.10 and 0.25 have also been tested. The Ni/Co/Al catalyst with the best results is that with a Co/Ni ratio of 0.10. For the Ni/Co/Al catalyst with Co/Ni = 0.10, the influence of the steam/carbon molar (S/C) ratio on gas yields has been studied for values from 5.5 to 1.5. Yields of H2 and CO2 decrease, while CH4 and CO yields increase when the S/C ratio diminishes. The influence of the catalyst weight/toluene flow rate (W/mt) ratio has been analyzed for Ni/Al/La catalyst with a La/Ni ratio of 0.088 and Ni/Co/Al catalyst with Co/Ni = 0.10. For both catalysts, carbon conversion to gas, total gas, H2 and CO2 yields increase when the W/mt ratio increases. textcopyright 2007 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Toluene has been chosen as a model compound of biomass gasification tar and its destruction has been studied by steam reforming. The experiments have been performed in a bench scale installation that uses a fluidized bed reactor with a technology very similar to the Waterloo Fast Pyrolysis Process (WFPP). All the experiments have been carried out at 650 °C and atmospheric pressure. Ni/Al/La catalysts with La/Ni ratios of 0, 0.044, 0.088 and 0.13 have been tested, the middle two showing the best performance. Ni/Co/Al catalysts with Co/Ni ratios of 0, 0.025, 0.10 and 0.25 have also been tested. The Ni/Co/Al catalyst with the best results is that with a Co/Ni ratio of 0.10. For the Ni/Co/Al catalyst with Co/Ni = 0.10, the influence of the steam/carbon molar (S/C) ratio on gas yields has been studied for values from 5.5 to 1.5. Yields of H2 and CO2 decrease, while CH4 and CO yields increase when the S/C ratio diminishes. The influence of the catalyst weight/toluene flow rate (W/mt) ratio has been analyzed for Ni/Al/La catalyst with a La/Ni ratio of 0.088 and Ni/Co/Al catalyst with Co/Ni = 0.10. For both catalysts, carbon conversion to gas, total gas, H2 and CO2 yields increase when the W/mt ratio increases. textcopyright 2007 Elsevier B.V. All rights reserved.
Guerrero, Marta; Ruiz, Pilar M; Millera, Ángela; Alzueta, María U; Bilbao, Rafael
Characterization of biomass chars formed under different devolatilization conditions: Differences between rice husk and Eucalyptus Artículo de revista
En: Energy and Fuels, vol. 22, no 2, pp. 1275–1284, 2008, ISSN: 08870624.
@article{Guerrero2008a,
title = {Characterization of biomass chars formed under different devolatilization conditions: Differences between rice husk and Eucalyptus},
author = {Marta Guerrero and Pilar M Ruiz and Ángela Millera and María U Alzueta and Rafael Bilbao},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ef7005589},
issn = {08870624},
year = {2008},
date = {2008-03-01},
journal = {Energy and Fuels},
volume = {22},
number = {2},
pages = {1275--1284},
publisher = {American Chemical Society},
abstract = {A comparison between the properties of chars produced by pyrolysis of rice husk and eucalyptus at different temperatures and heating rates has been performed. Low heating rate (LHR) devolatilization experiments were conducted in a fixed bed reactor at temperatures ranging from 600 to 900 °C, while a fluidized bed reactor was used for preparing chars at high heating rate (HHR) and temperatures of 800 and 900 °C. The morphological changes in carbonaceous solids produced in the different thermal treatments were observed by scanning electron microscopy (SEM). X-ray diffraction (XRD) and Raman spectra were obtained to evaluate the degree of char structural order. The chars were characterized by their ultimate analysis, oxygen functional group content, and CO2 adsorption at 0 °C using the Dubinin-Radushkevich method. The results obtained from the different techniques were contrasted to give an overview of the chemical and physical properties of the biomass char samples studied. The influence of the parent material and char properties on char reactivity toward O2 and NO reduction was further investigated. It was found that, though rice husk chars have a greater reactivity toward oxygen, the NO reduction ability was significantly higher for the eucalyptus chars. textcopyright 2008 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A comparison between the properties of chars produced by pyrolysis of rice husk and eucalyptus at different temperatures and heating rates has been performed. Low heating rate (LHR) devolatilization experiments were conducted in a fixed bed reactor at temperatures ranging from 600 to 900 °C, while a fluidized bed reactor was used for preparing chars at high heating rate (HHR) and temperatures of 800 and 900 °C. The morphological changes in carbonaceous solids produced in the different thermal treatments were observed by scanning electron microscopy (SEM). X-ray diffraction (XRD) and Raman spectra were obtained to evaluate the degree of char structural order. The chars were characterized by their ultimate analysis, oxygen functional group content, and CO2 adsorption at 0 °C using the Dubinin-Radushkevich method. The results obtained from the different techniques were contrasted to give an overview of the chemical and physical properties of the biomass char samples studied. The influence of the parent material and char properties on char reactivity toward O2 and NO reduction was further investigated. It was found that, though rice husk chars have a greater reactivity toward oxygen, the NO reduction ability was significantly higher for the eucalyptus chars. textcopyright 2008 American Chemical Society.
Alzueta, María U; Borruey, M; Callejas, Alicia; Millera, Ángela; Bilbao, Rafael
An experimental and modeling study of the oxidation of acetylene in a flow reactor Artículo de revista
En: Combustion and Flame, vol. 152, no 3, pp. 377–386, 2008, ISSN: 00102180.
@article{Alzueta2008,
title = {An experimental and modeling study of the oxidation of acetylene in a flow reactor},
author = {María U Alzueta and M Borruey and Alicia Callejas and Ángela Millera and Rafael Bilbao},
doi = {10.1016/j.combustflame.2007.10.011},
issn = {00102180},
year = {2008},
date = {2008-02-01},
journal = {Combustion and Flame},
volume = {152},
number = {3},
pages = {377--386},
publisher = {Elsevier},
abstract = {Acetylene is a hydrocarbon of significance in a variety of processes. It is an intermediate species during combustion processes and it is recognized as one of the most important soot precursors. Despite the large number of studies carried out in the past decades in relation to acetylene conversion in a variety of reactors (shock tubes, flames, and jet-stirred reactors) and operating conditions (from rich to lean environments, at different temperatures and pressures), the conversion of acetylene is not yet well described. An experimental and theoretical study of the oxidation of acetylene at atmospheric pressure in the temperature range 700-1500 K, and from fuel-rich to significantly fuel-lean conditions, has been performed. The experiments were conducted in an isothermal quartz flow reactor and the influence of the temperature and stoichiometry (by varying the O2 concentration for a given C2H2 initial level) on the concentrations of C2H2, CO, and CO2 has been analyzed. A reaction mechanism based on the model of Glarborg et al. [Combust. Flame 115 (1998) 1-27] for hydrocarbon/NO interactions, updated by Glarborg et al. [Combust. Flame 132 (2003) 629-638], and the model of Skjøth-Rasmussen et al. [Proc. Combust. Inst. 29 (2002) 1329-1336] for benzene formation, using methane as the initial hydrocarbon, has been used for calculations. The results show the oxidation regime of acetylene for different air excess conditions and the model developed allows a fairly good description of the experiments made. The experimental results are analyzed in terms of detailed chemistry and the main issues are discussed. The model here used should be further included in more detailed kinetic schemes and models developed to describe not only hydrocarbon conversion but also soot formation. textcopyright 2007 The Combustion Institute.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Acetylene is a hydrocarbon of significance in a variety of processes. It is an intermediate species during combustion processes and it is recognized as one of the most important soot precursors. Despite the large number of studies carried out in the past decades in relation to acetylene conversion in a variety of reactors (shock tubes, flames, and jet-stirred reactors) and operating conditions (from rich to lean environments, at different temperatures and pressures), the conversion of acetylene is not yet well described. An experimental and theoretical study of the oxidation of acetylene at atmospheric pressure in the temperature range 700-1500 K, and from fuel-rich to significantly fuel-lean conditions, has been performed. The experiments were conducted in an isothermal quartz flow reactor and the influence of the temperature and stoichiometry (by varying the O2 concentration for a given C2H2 initial level) on the concentrations of C2H2, CO, and CO2 has been analyzed. A reaction mechanism based on the model of Glarborg et al. [Combust. Flame 115 (1998) 1-27] for hydrocarbon/NO interactions, updated by Glarborg et al. [Combust. Flame 132 (2003) 629-638], and the model of Skjøth-Rasmussen et al. [Proc. Combust. Inst. 29 (2002) 1329-1336] for benzene formation, using methane as the initial hydrocarbon, has been used for calculations. The results show the oxidation regime of acetylene for different air excess conditions and the model developed allows a fairly good description of the experiments made. The experimental results are analyzed in terms of detailed chemistry and the main issues are discussed. The model here used should be further included in more detailed kinetic schemes and models developed to describe not only hydrocarbon conversion but also soot formation. textcopyright 2007 The Combustion Institute.
Mendiara, Teresa; Alzueta, María U; Millera, Ángela; Bilbao, Rafael
Influence of the NO concentration and the presence of oxygen in the acetylene soot reaction with NO Artículo de revista
En: Energy and Fuels, vol. 22, no 1, pp. 284–290, 2008, ISSN: 08870624.
@article{Mendiara2008,
title = {Influence of the NO concentration and the presence of oxygen in the acetylene soot reaction with NO},
author = {Teresa Mendiara and María U Alzueta and Ángela Millera and Rafael Bilbao},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ef700580t},
issn = {08870624},
year = {2008},
date = {2008-01-01},
journal = {Energy and Fuels},
volume = {22},
number = {1},
pages = {284--290},
publisher = {American Chemical Society},
abstract = {Two different soot samples were produced by acetylene pyrolysis at 1100 °C using 50 000 ppmv (soot A) and 5000 ppmv (soot B) initial acetylene concentrations. Both soot samples exhibited different properties. Soot A presented a lower BET surface area, higher C/H ratio, and larger particles than soot B. At 1100 °C, soot - NO reaction was analyzed for both soot samples using a wide range of NO concentrations (300-3000 ppmv). Reaction order with respect to NO was determined, according to the shrinking core model with chemical reaction control, resulting in 0.5 for soot A and 0.7 for soot B. The influence of the oxygen presence on soot A and B reaction with NO was also analyzed. At 1100 °C and for a given NO concentration of 2150 ppmv, different oxygen concentrations between 250 and 5000 ppmv were tested. The presence of oxygen resulted in some cases in an increase in NO reduction. The analysis of the carbon consumption rates of the experiments in which oxygen was present revealed a competition between oxygen and NO for soot particle. textcopyright 2008 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Two different soot samples were produced by acetylene pyrolysis at 1100 °C using 50 000 ppmv (soot A) and 5000 ppmv (soot B) initial acetylene concentrations. Both soot samples exhibited different properties. Soot A presented a lower BET surface area, higher C/H ratio, and larger particles than soot B. At 1100 °C, soot – NO reaction was analyzed for both soot samples using a wide range of NO concentrations (300-3000 ppmv). Reaction order with respect to NO was determined, according to the shrinking core model with chemical reaction control, resulting in 0.5 for soot A and 0.7 for soot B. The influence of the oxygen presence on soot A and B reaction with NO was also analyzed. At 1100 °C and for a given NO concentration of 2150 ppmv, different oxygen concentrations between 250 and 5000 ppmv were tested. The presence of oxygen resulted in some cases in an increase in NO reduction. The analysis of the carbon consumption rates of the experiments in which oxygen was present revealed a competition between oxygen and NO for soot particle. textcopyright 2008 American Chemical Society.
2007
Artículos de revista
Manyà, Joan Josep; Ruiz, Joaquín; Arauzo, Jesús
Some peculiarities of conventional pyrolysis of several agricultural residues in a packed bed reactor Artículo de revista
En: vol. 46, no 26, pp. 9061–9070, 2007, ISSN: 08885885.
@article{Manya2007,
title = {Some peculiarities of conventional pyrolysis of several agricultural residues in a packed bed reactor},
author = {Joan Josep Manyà and Joaquín Ruiz and Jesús Arauzo},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ie070811c},
issn = {08885885},
year = {2007},
date = {2007-12-01},
booktitle = {Industrial and Engineering Chemistry Research},
volume = {46},
number = {26},
pages = {9061--9070},
publisher = {American Chemical Society},
abstract = {The pyrolytic behavior of four agricultural wastes which are very abundant in Spain (almond shells, wheat straw, grape refuse, and olive stones) has been investigated using a bench scale system. Conventional pyrolysis experiments were performed in a packed bed reactor (58 mm i.d.) at 5, 10, 15, and 30 K min -1 for a final temperature of 923 K. Temperature profiles, conversion times, product yields (gases, liquids, and char), and gas composition have been analyzed to investigate the influence of the biomass composition and the operating conditions on the process. Large differences were noted in the pyrolysis outputs when the heating rate is increased to 30 K min-1. In the case of almond shell samples, higher devolatilization rates accompanied by an increase in secondary charring reactions were observed at 30 K min -1, probably due to the chemical composition of the inorganic fraction present in the almond shells. In addition, when the heating rate is increased to 30 K min-1, the lignin content does not seem to have a substantial effect on the product distribution. This fact suggests that this heating rate value could be a heating requirement in which the majority of pyrolysis does not occur in the low-temperature region. textcopyright 2007 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The pyrolytic behavior of four agricultural wastes which are very abundant in Spain (almond shells, wheat straw, grape refuse, and olive stones) has been investigated using a bench scale system. Conventional pyrolysis experiments were performed in a packed bed reactor (58 mm i.d.) at 5, 10, 15, and 30 K min -1 for a final temperature of 923 K. Temperature profiles, conversion times, product yields (gases, liquids, and char), and gas composition have been analyzed to investigate the influence of the biomass composition and the operating conditions on the process. Large differences were noted in the pyrolysis outputs when the heating rate is increased to 30 K min-1. In the case of almond shell samples, higher devolatilization rates accompanied by an increase in secondary charring reactions were observed at 30 K min -1, probably due to the chemical composition of the inorganic fraction present in the almond shells. In addition, when the heating rate is increased to 30 K min-1, the lignin content does not seem to have a substantial effect on the product distribution. This fact suggests that this heating rate value could be a heating requirement in which the majority of pyrolysis does not occur in the low-temperature region. textcopyright 2007 American Chemical Society.
Mendiara, Teresa; Millera, Ángela; Alzueta, María U; Bilbao, Rafael
A comparison of acetylene soot and two different carbon blacks: Reactivity to oxygen and NO Artículo de revista
En: International Journal of Chemical Reactor Engineering, vol. 5, no 1, 2007, ISSN: 15426580.
@article{Mendiara2007a,
title = {A comparison of acetylene soot and two different carbon blacks: Reactivity to oxygen and NO},
author = {Teresa Mendiara and Ángela Millera and María U Alzueta and Rafael Bilbao},
url = {https://www.degruyter.com/view/journals/ijcre/5/1/article-ijcre.2007.5.1.1510.xml.xml},
doi = {10.2202/1542-6580.1510},
issn = {15426580},
year = {2007},
date = {2007-11-01},
journal = {International Journal of Chemical Reactor Engineering},
volume = {5},
number = {1},
publisher = {Walter de Gruyter GmbH},
abstract = {There is not much known about the reactivity of hydrocarbon soot to oxygen and NO. According to the chemical and structural properties of one soot obtained from acetylene pyrolysis, SEVACARB MT and CABOT carbon blacks were selected to perform a reactivity study. The properties of the materials were determined through ultimate and proximate analysis as well as SEM, TEM and XRD techniques. A study of the oxidation of the three materials is performed for different oxidation conditions of temperature (1123-1273 K) and oxygen concentration (100-1000 ppmv). The reaction of acetylene soot with NO and SEVACARB MT carbon black is carried out at 1373 K with 1800-3000 ppmv NO. Results are compared to analyze their reactivity similarities and the possibility of using carbon blacks as acetylene soot substitutes in laboratory work. Copyright textcopyright 2007 The Berkeley Electronic Press. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
There is not much known about the reactivity of hydrocarbon soot to oxygen and NO. According to the chemical and structural properties of one soot obtained from acetylene pyrolysis, SEVACARB MT and CABOT carbon blacks were selected to perform a reactivity study. The properties of the materials were determined through ultimate and proximate analysis as well as SEM, TEM and XRD techniques. A study of the oxidation of the three materials is performed for different oxidation conditions of temperature (1123-1273 K) and oxygen concentration (100-1000 ppmv). The reaction of acetylene soot with NO and SEVACARB MT carbon black is carried out at 1373 K with 1800-3000 ppmv NO. Results are compared to analyze their reactivity similarities and the possibility of using carbon blacks as acetylene soot substitutes in laboratory work. Copyright textcopyright 2007 The Berkeley Electronic Press. All rights reserved.
Mendiara, Teresa; Alzueta, María U; Millera, Ángela; Bilbao, Rafael
Oxidation of acetylene soot: Influence of oxygen concentration Artículo de revista
En: Energy and Fuels, vol. 21, no 6, pp. 3208–3215, 2007, ISSN: 08870624.
@article{Mendiara2007b,
title = {Oxidation of acetylene soot: Influence of oxygen concentration},
author = {Teresa Mendiara and María U Alzueta and Ángela Millera and Rafael Bilbao},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ef070182j},
issn = {08870624},
year = {2007},
date = {2007-11-01},
journal = {Energy and Fuels},
volume = {21},
number = {6},
pages = {3208--3215},
publisher = {American Chemical Society},
abstract = {Soot was produced from acetylene pyrolysis at 1100 °C using 50 000 ppmv acetylene. At 900 and 1100 °C, the influence of the oxygen concentration in a range of 100-30 000 ppmv was analyzed. Applying the shrinking core model with decreasing particle size and chemical reaction control, the reaction order with respect to oxygen was obtained, which turned out to be 1. Experiments at 850 and 1000 °C with an oxygen concentration of 500 ppmv were also done to extend the study of the temperature influence. The activation energy of the soot oxidation process was also obtained and resulted in a value of 42.8 kJ/mol. Additionally, another soot with different structural characteristics was obtained by acetylene pyrolysis at 1100 °C, using 5000 ppmv acetylene. Its oxidation over a range of oxygen concentrations (250-20 000 ppmv) was studied. The shrinking core model with chemical reaction control was also applied, and the reaction order with respect to oxygen was obtained, again being equal to unity. textcopyright 2007 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Soot was produced from acetylene pyrolysis at 1100 °C using 50 000 ppmv acetylene. At 900 and 1100 °C, the influence of the oxygen concentration in a range of 100-30 000 ppmv was analyzed. Applying the shrinking core model with decreasing particle size and chemical reaction control, the reaction order with respect to oxygen was obtained, which turned out to be 1. Experiments at 850 and 1000 °C with an oxygen concentration of 500 ppmv were also done to extend the study of the temperature influence. The activation energy of the soot oxidation process was also obtained and resulted in a value of 42.8 kJ/mol. Additionally, another soot with different structural characteristics was obtained by acetylene pyrolysis at 1100 °C, using 5000 ppmv acetylene. Its oxidation over a range of oxygen concentrations (250-20 000 ppmv) was studied. The shrinking core model with chemical reaction control was also applied, and the reaction order with respect to oxygen was obtained, again being equal to unity. textcopyright 2007 American Chemical Society.
Ruiz, Pilar M; Villoria, R Guzmán De; Millera, Ángela; Alzueta, María U; Bilbao, Rafael
Influence of different operation conditions on soot formation from C 2H2 pyrolysis Artículo de revista
En: Industrial and Engineering Chemistry Research, vol. 46, no 23, pp. 7550–7560, 2007, ISSN: 08885885.
@article{Ruiz2007c,
title = {Influence of different operation conditions on soot formation from C 2H2 pyrolysis},
author = {Pilar M Ruiz and R Guzmán De Villoria and Ángela Millera and María U Alzueta and Rafael Bilbao},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ie070008i},
issn = {08885885},
year = {2007},
date = {2007-11-01},
journal = {Industrial and Engineering Chemistry Research},
volume = {46},
number = {23},
pages = {7550--7560},
publisher = {American Chemical Society},
abstract = {The influence of different operation conditions (temperature, inlet acetylene concentration, and gas residence time) on the formation of soot from C2H2 pyrolysis has been studied. Pyrolysis experiments were carried out in a quartz reactor in the 1000-1200°C temperature range, for different inlet C2H2 concentrations (15 000, 30 000, and 50 000 ppmv) and two gas residence times (1 706/T (K) and 4 552/T (K) s). Outlet gases were analyzed by gas chromatography, and the amount of soot produced was measured. The reactivity of the soot samples formed toward O 2 was also studied. The results are supported by means of different soot characterization techniques: elemental analysis, determination of Brunauer-Emmett-Teller (BET) area, transmission electron microscopy, and Raman spectroscopy. A study of the influence of these operation conditions on the resultant soot oxidative reactivities has been carried out. textcopyright 2007 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The influence of different operation conditions (temperature, inlet acetylene concentration, and gas residence time) on the formation of soot from C2H2 pyrolysis has been studied. Pyrolysis experiments were carried out in a quartz reactor in the 1000-1200°C temperature range, for different inlet C2H2 concentrations (15 000, 30 000, and 50 000 ppmv) and two gas residence times (1 706/T (K) and 4 552/T (K) s). Outlet gases were analyzed by gas chromatography, and the amount of soot produced was measured. The reactivity of the soot samples formed toward O 2 was also studied. The results are supported by means of different soot characterization techniques: elemental analysis, determination of Brunauer-Emmett-Teller (BET) area, transmission electron microscopy, and Raman spectroscopy. A study of the influence of these operation conditions on the resultant soot oxidative reactivities has been carried out. textcopyright 2007 American Chemical Society.
Mastral, José Francisco; Berrueco, César; Ceamanos, Jesús
Theoretical prediction of product distribution of the pyrolysis of high density polyethylene Artículo de revista
En: Journal of Analytical and Applied Pyrolysis, vol. 80, no 2, pp. 427–438, 2007, ISSN: 01652370.
@article{Mastral2007b,
title = {Theoretical prediction of product distribution of the pyrolysis of high density polyethylene},
author = {José Francisco Mastral and César Berrueco and Jesús Ceamanos},
doi = {10.1016/j.jaap.2006.07.009},
issn = {01652370},
year = {2007},
date = {2007-10-01},
journal = {Journal of Analytical and Applied Pyrolysis},
volume = {80},
number = {2},
pages = {427--438},
publisher = {Elsevier},
abstract = {The main objective of this work is the formulation and development of a model that predicts the product distribution obtained in the pyrolysis of polyethylene. In order to do this a mechanistic model has been developed based on a radical mechanism. This model uses a small number of elementary kinetic steps, including initiation, $beta$-scission, H-abstraction, aromatization and radical combination. The mechanism allows the prediction of the compounds obtained during the pyrolysis. Given the great number of species considered, the simulation of the pyrolysis process requires the solution of complex systems of ordinary differential equations. The results obtained have been validated with experimental results obtained in a free fall installation in which the pyrolysis process has been studied at different temperatures (500-1000 °C) and residence times (0.52-2.07 s). textcopyright 2007 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The main objective of this work is the formulation and development of a model that predicts the product distribution obtained in the pyrolysis of polyethylene. In order to do this a mechanistic model has been developed based on a radical mechanism. This model uses a small number of elementary kinetic steps, including initiation, $beta$-scission, H-abstraction, aromatization and radical combination. The mechanism allows the prediction of the compounds obtained during the pyrolysis. Given the great number of species considered, the simulation of the pyrolysis process requires the solution of complex systems of ordinary differential equations. The results obtained have been validated with experimental results obtained in a free fall installation in which the pyrolysis process has been studied at different temperatures (500-1000 °C) and residence times (0.52-2.07 s). textcopyright 2007 Elsevier B.V. All rights reserved.
Ruiz, Pilar M; Callejas, Alicia; Millera, Ángela; Alzueta, María U; Bilbao, Rafael
Reactivity towards O2 and NO of the soot formed from ethylene pyrolysis at different temperatures Artículo de revista
En: International Journal of Chemical Reactor Engineering, vol. 5, no 1, 2007, ISSN: 15426580.
@article{Ruiz2007a,
title = {Reactivity towards O2 and NO of the soot formed from ethylene pyrolysis at different temperatures},
author = {Pilar M Ruiz and Alicia Callejas and Ángela Millera and María U Alzueta and Rafael Bilbao},
url = {https://www.degruyter.com/view/journals/ijcre/5/1/article-ijcre.2007.5.1.1478.xml.xml},
doi = {10.2202/1542-6580.1478},
issn = {15426580},
year = {2007},
date = {2007-09-01},
journal = {International Journal of Chemical Reactor Engineering},
volume = {5},
number = {1},
publisher = {Walter de Gruyter GmbH},
abstract = {The influence of temperature on the formation of soot from ethylene pyrolysis has been studied. Pyrolysis experiments were carried out in a quartz reactor in the 1000-1200°C temperature range, for an inlet C 2H4 concentration of 50000 ppmv and a gas residence time of 4552/T(K) seconds. Outlet gases were analyzed by gas chromatography and the amount of soot produced measured. The reactivity of the soot samples obtained towards O2 and NO was also studied. Results show that the higher the formation temperature, the less reactive the soot. The soot samples were further characterized using elemental analysis, scanning electron microscopy and Raman spectroscopy, in order to study their structural properties, and relate them to their reactivity. Additionally, a comparison of the reactivity towards NO between acetylene and ethylene soot samples obtained under similar conditions has been carried out. The soot samples obtained from ethylene pyrolysis present higher reactivity towards NO than the soot samples formed from acetylene. Copyright textcopyright 2007 The Berkeley Electronic Press. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The influence of temperature on the formation of soot from ethylene pyrolysis has been studied. Pyrolysis experiments were carried out in a quartz reactor in the 1000-1200°C temperature range, for an inlet C 2H4 concentration of 50000 ppmv and a gas residence time of 4552/T(K) seconds. Outlet gases were analyzed by gas chromatography and the amount of soot produced measured. The reactivity of the soot samples obtained towards O2 and NO was also studied. Results show that the higher the formation temperature, the less reactive the soot. The soot samples were further characterized using elemental analysis, scanning electron microscopy and Raman spectroscopy, in order to study their structural properties, and relate them to their reactivity. Additionally, a comparison of the reactivity towards NO between acetylene and ethylene soot samples obtained under similar conditions has been carried out. The soot samples obtained from ethylene pyrolysis present higher reactivity towards NO than the soot samples formed from acetylene. Copyright textcopyright 2007 The Berkeley Electronic Press. All rights reserved.
Liesa, Fernando; Alzueta, María U; Millera, Ángela; Bilbao, Rafael
Influence of reactant mixing in a laminar flow reactor: the case of gas reburning. 1. Experimental study Artículo de revista
En: Industrial and Engineering Chemistry Research, vol. 46, no 11, pp. 3520–3527, 2007, ISSN: 08885885.
@article{Liesa2007a,
title = {Influence of reactant mixing in a laminar flow reactor: the case of gas reburning. 1. Experimental study},
author = {Fernando Liesa and María U Alzueta and Ángela Millera and Rafael Bilbao},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ie060943q},
issn = {08885885},
year = {2007},
date = {2007-05-01},
journal = {Industrial and Engineering Chemistry Research},
volume = {46},
number = {11},
pages = {3520--3527},
publisher = {American Chemical Society},
abstract = {An experimental work of the reburn process in a laminar flow reactor with two coaxial feeding streams has been performed, with the objective of analyzing the influence of reactant mixing in this reactive system. The ways of reaching different mixing conditions have been diverse: by means of changing the velocity ratio among the two streams through which reactants are fed into the reactor, and by introducing the reactants into the reactor through different conducts (fuel introduced through the inner stream and oxidant introduced through the outer stream and vice versa). Moreover, the influence of the main variables of the reburn processaverage residence time, temperature, and stoichiometry-has been studied under laminar flow conditions. In addition, the results achieved in the present work have been compared with data from the literature obtained from experiments conducted under ideal plug-flow reactor conditions. The results show an important influence of the reactant injection mode, which affects the reaction conditions. That influence is mostly attributed to the combination of the effects of the local stoichiometry conditions within the reaction zone and the residence time distribution. textcopyright 2007 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An experimental work of the reburn process in a laminar flow reactor with two coaxial feeding streams has been performed, with the objective of analyzing the influence of reactant mixing in this reactive system. The ways of reaching different mixing conditions have been diverse: by means of changing the velocity ratio among the two streams through which reactants are fed into the reactor, and by introducing the reactants into the reactor through different conducts (fuel introduced through the inner stream and oxidant introduced through the outer stream and vice versa). Moreover, the influence of the main variables of the reburn processaverage residence time, temperature, and stoichiometry-has been studied under laminar flow conditions. In addition, the results achieved in the present work have been compared with data from the literature obtained from experiments conducted under ideal plug-flow reactor conditions. The results show an important influence of the reactant injection mode, which affects the reaction conditions. That influence is mostly attributed to the combination of the effects of the local stoichiometry conditions within the reaction zone and the residence time distribution. textcopyright 2007 American Chemical Society.