1998
Journal Articles
Alzueta, María U; Oliva, Miriam; Glarborg, Peter
Parabenzoquinone pyrolysis and oxidation in a flow reactor Journal Article
In: International Journal of Chemical Kinetics, vol. 30, no. 9, pp. 683–697, 1998, ISSN: 05388066.
@article{Alzueta1998c,
title = {Parabenzoquinone pyrolysis and oxidation in a flow reactor},
author = {María U Alzueta and Miriam Oliva and Peter Glarborg},
url = {https://orbit.dtu.dk/en/publications/parabenzoquinone-pyrolysis-and-oxidation-in-a-flow-reactor},
doi = {10.1002/(SICI)1097-4601(1998)30:9<683::AID-KIN9>3.0.CO;2-O},
issn = {05388066},
year = {1998},
date = {1998-01-01},
journal = {International Journal of Chemical Kinetics},
volume = {30},
number = {9},
pages = {683--697},
publisher = {John Wiley and Sons Inc.},
abstract = {An experimental and theoretical study of the pyrolysis and oxidation of parabenzoquinone has been performed. The experiments were conducted in an isothermal quartz flow reactor at atmospheric pressure in the temperature range 600-1500 K. The main variables considered are temperature, oxygen concentration, and presence of CO. A detailed reaction mechanism for the pyrolysis and oxidation chemistry of parabenzoquinone is proposed, which provides a good description of the experimental results. Both the experimental work and the kinetic mechanism proposed for the pyrolysis and oxidation of parabenzoquinone represent the first systematic study carried out for this important aromatic compound. Our pyrolysis results confirm that the primary dissociation channel for p-benzoquinone leads to CO and a C5H4O isomer, presumably cyclopentadienone. However, significant formation of CO2 during the pyrolysis may indicate the existence of a secondary dissociation channel leading to CO2 and a C5H4 isomer. Under oxidizing conditions, consumption of p-benzoquinone occurs mainly by dissociation at lower temperatures. As the temperature increases interaction of OC6H4O with the radical pool becomes more significant, occurring primarily through hydrogen abstraction reactions followed by ring opening reactions of the OC6H3O radical. textcopyright 1998 John Wiley & Sons, Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An experimental and theoretical study of the pyrolysis and oxidation of parabenzoquinone has been performed. The experiments were conducted in an isothermal quartz flow reactor at atmospheric pressure in the temperature range 600-1500 K. The main variables considered are temperature, oxygen concentration, and presence of CO. A detailed reaction mechanism for the pyrolysis and oxidation chemistry of parabenzoquinone is proposed, which provides a good description of the experimental results. Both the experimental work and the kinetic mechanism proposed for the pyrolysis and oxidation of parabenzoquinone represent the first systematic study carried out for this important aromatic compound. Our pyrolysis results confirm that the primary dissociation channel for p-benzoquinone leads to CO and a C5H4O isomer, presumably cyclopentadienone. However, significant formation of CO2 during the pyrolysis may indicate the existence of a secondary dissociation channel leading to CO2 and a C5H4 isomer. Under oxidizing conditions, consumption of p-benzoquinone occurs mainly by dissociation at lower temperatures. As the temperature increases interaction of OC6H4O with the radical pool becomes more significant, occurring primarily through hydrogen abstraction reactions followed by ring opening reactions of the OC6H3O radical. textcopyright 1998 John Wiley & Sons, Inc.
1997
Journal Articles
Bilbao, Rafael; Millera, Ángela; Alzueta, María U; Prada, Lina
Evaluation of the use of different hydrocarbon fuels for gas reburning Journal Article
In: Fuel, vol. 76, no. 14-15, pp. 1401–1407, 1997, ISSN: 00162361.
@article{Bilbao1997d,
title = {Evaluation of the use of different hydrocarbon fuels for gas reburning},
author = {Rafael Bilbao and Ángela Millera and María U Alzueta and Lina Prada},
doi = {10.1016/S0016-2361(97)00131-2},
issn = {00162361},
year = {1997},
date = {1997-11-01},
journal = {Fuel},
volume = {76},
number = {14-15},
pages = {1401--1407},
publisher = {Elsevier Ltd},
abstract = {Gas reburning is a NO$chi$ reduction technique that has been demonstrated to be efficient in different combustion systems. An experimental study of gas reburning performance in the low temperature range (at and under 1100°C) has been carried out. An evaluation of the use of different hydrocarbon fuels, such as natural gas, methane, ethane, ethylene and acetylene was performed and the influence of the temperature and stoichiometry is considered. The results show that the reburning process is effective under appropriate conditions at the low temperatures used in this work. However, as the temperature diminishes, the influence of the reburn fuel becomes more marked and the use of acetylene or ethane and ethylene leads to better performance than natural gas or methane, the classical reburn fuels for high temperature applications. textcopyright 1997 Elsevier Science Ltd.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gas reburning is a NO$chi$ reduction technique that has been demonstrated to be efficient in different combustion systems. An experimental study of gas reburning performance in the low temperature range (at and under 1100°C) has been carried out. An evaluation of the use of different hydrocarbon fuels, such as natural gas, methane, ethane, ethylene and acetylene was performed and the influence of the temperature and stoichiometry is considered. The results show that the reburning process is effective under appropriate conditions at the low temperatures used in this work. However, as the temperature diminishes, the influence of the reburn fuel becomes more marked and the use of acetylene or ethane and ethylene leads to better performance than natural gas or methane, the classical reburn fuels for high temperature applications. textcopyright 1997 Elsevier Science Ltd.
Kifani-Sahban, F; Kifani, A; Belkbir, L; Zoulalian, A; Arauzo, Jesús; Cardero, T
A physical approach in the understanding of the phenomena accompanying the thermal treatment of lignin Journal Article
In: Thermochimica Acta, vol. 298, no. 1-2, pp. 199–204, 1997, ISSN: 00406031.
@article{Kifani-Sahban1997,
title = {A physical approach in the understanding of the phenomena accompanying the thermal treatment of lignin},
author = {F Kifani-Sahban and A Kifani and L Belkbir and A Zoulalian and Jesús Arauzo and T Cardero},
doi = {10.1016/s0040-6031(97)00115-9},
issn = {00406031},
year = {1997},
date = {1997-09-01},
journal = {Thermochimica Acta},
volume = {298},
number = {1-2},
pages = {199--204},
publisher = {Elsevier},
abstract = {In this work, a mechanical approach is associated with the thermal behavior of lignin. Samples of lignin are submitted to a thermal treatment accomplished at different final temperatures of pyrolysis. The dimensional variations which occurred during the degradation of lignin are quantified by the Jacobian of the transformation. The increase of the Jacobian in the interval 180 to 260°C signifies the formation and the development of a plastic phase by crazing as is indicated by scanning electron microscope micrographs of lignin residues. The apparition and the evolution of the plastic phase are not a new fact in fracture mechanics, but the characterisation of this phase and the mechanics of its formation and its fracture allow us to explain some aspects until now unknown in the thermal decomposition of lignin. The importance of this work relies on the analogy made between the thermal behaviour of lignin and the mechanical behaviour of polymers. This analogy permits us to make some interpretations and, for the first time, to explain the weak weight loss and the exothermic effect of the thermal degradation of lignin. textcopyright 1997 Elsevier Science B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work, a mechanical approach is associated with the thermal behavior of lignin. Samples of lignin are submitted to a thermal treatment accomplished at different final temperatures of pyrolysis. The dimensional variations which occurred during the degradation of lignin are quantified by the Jacobian of the transformation. The increase of the Jacobian in the interval 180 to 260°C signifies the formation and the development of a plastic phase by crazing as is indicated by scanning electron microscope micrographs of lignin residues. The apparition and the evolution of the plastic phase are not a new fact in fracture mechanics, but the characterisation of this phase and the mechanics of its formation and its fracture allow us to explain some aspects until now unknown in the thermal decomposition of lignin. The importance of this work relies on the analogy made between the thermal behaviour of lignin and the mechanical behaviour of polymers. This analogy permits us to make some interpretations and, for the first time, to explain the weak weight loss and the exothermic effect of the thermal degradation of lignin. textcopyright 1997 Elsevier Science B.V.
Bilbao, Rafael; Arauzo, Jesús; Murillo, María Benita; Salvador, María L
Gas formation in the thermal decomposition of large spherical wood particles Journal Article
In: Journal of Analytical and Applied Pyrolysis, vol. 43, no. 1, pp. 27–39, 1997, ISSN: 01652370.
@article{Bilbao1997c,
title = {Gas formation in the thermal decomposition of large spherical wood particles},
author = {Rafael Bilbao and Jesús Arauzo and María Benita Murillo and María L Salvador},
doi = {10.1016/S0165-2370(97)00056-9},
issn = {01652370},
year = {1997},
date = {1997-08-01},
journal = {Journal of Analytical and Applied Pyrolysis},
volume = {43},
number = {1},
pages = {27--39},
publisher = {Elsevier},
abstract = {Gas formation, weight loss and temperature profiles in the thermal decomposition of relatively large particles of pine wood have been studied. Experiments with spherical particles of different sizes (2, 3 and 4 cm in diameter) have been carried out at two heating rates of the system (5 and 12°C min-1). The existence of significant radial and angular profiles in the particles causes differences in the conversion and in the formation of gases. The experimental yields obtained for the majority gas, CO2, have been compared with the calculated yields using a model without adjustable parameters. An acceptable agreement has been achieved between the experimental and calculated results. textcopyright 1997 Elsevier Science B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gas formation, weight loss and temperature profiles in the thermal decomposition of relatively large particles of pine wood have been studied. Experiments with spherical particles of different sizes (2, 3 and 4 cm in diameter) have been carried out at two heating rates of the system (5 and 12°C min-1). The existence of significant radial and angular profiles in the particles causes differences in the conversion and in the formation of gases. The experimental yields obtained for the majority gas, CO2, have been compared with the calculated yields using a model without adjustable parameters. An acceptable agreement has been achieved between the experimental and calculated results. textcopyright 1997 Elsevier Science B.V.
Bilbao, Rafael; Mastral, José Francisco; Aldea, María E; Ceamanos, Jesús
The influence of the percentage of oxygen in the atmosphere on the thermal decomposition of lignocellulosic materials Journal Article
In: Journal of Analytical and Applied Pyrolysis, vol. 42, no. 2, pp. 189–202, 1997, ISSN: 01652370.
@article{Bilbao1997b,
title = {The influence of the percentage of oxygen in the atmosphere on the thermal decomposition of lignocellulosic materials},
author = {Rafael Bilbao and José Francisco Mastral and María E Aldea and Jesús Ceamanos},
doi = {10.1016/S0165-2370(97)00050-8},
issn = {01652370},
year = {1997},
date = {1997-07-01},
journal = {Journal of Analytical and Applied Pyrolysis},
volume = {42},
number = {2},
pages = {189--202},
publisher = {Elsevier},
abstract = {Dynamic experiments with a heating rate of 12°C min-1 have been carried out for different oxygen concentrations and several types of pine samples. The influence of the initial solid weight and the sample shape on the solid conversion for each oxygen concentration has been analysed. A simple method is proposed to predict the solid conversion for different oxygen concentrations. The kinetic equations corresponding to an air atmosphere are used in this method. textcopyright 1997 Elsevier Science B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Dynamic experiments with a heating rate of 12°C min-1 have been carried out for different oxygen concentrations and several types of pine samples. The influence of the initial solid weight and the sample shape on the solid conversion for each oxygen concentration has been analysed. A simple method is proposed to predict the solid conversion for different oxygen concentrations. The kinetic equations corresponding to an air atmosphere are used in this method. textcopyright 1997 Elsevier Science B.V.
Alzueta, María U; Glarborg, Peter; Dam-Johansen, Kim
Low temperature interactions between hydrocarbons and nitric oxide: An experimental study Journal Article
In: Combustion and Flame, vol. 109, no. 1-2, pp. 25–36, 1997, ISSN: 00102180.
@article{Alzueta1997a,
title = {Low temperature interactions between hydrocarbons and nitric oxide: An experimental study},
author = {María U Alzueta and Peter Glarborg and Kim Dam-Johansen},
doi = {10.1016/S0010-2180(96)00146-0},
issn = {00102180},
year = {1997},
date = {1997-04-01},
journal = {Combustion and Flame},
volume = {109},
number = {1-2},
pages = {25--36},
publisher = {Elsevier},
abstract = {Gas reburning is a NO(x) control technique that can be applied in different combustion systems. In it, gas is injected into the furnace downstream of the primary burners to form a substoichiometric zone followed by the injection of burnout air. The variables that influence the chemistry in the reducing zone (temperature between 900 and 1450 K, reburn fuel type, stoichiometry, NO concentration and residence time), which is mainly controlled by the interactions between hydrocarbon radicals and NO, have been studied in a laboratory scale flow reactor. A significant NO reduction efficiency can be obtained with proper operating conditions. The NO destruction is closely coupled to the hydrocarbon oxidation regime, which differs depending on the hydrocarbon fuel considered, and NO is to a significant extent converted to HCN. The concentration of hydrocarbons and oxygen, and the temperature are important parameters affecting the results obtained, whereas the inlet NO concentration and the residence time only have a minor effect. The practical implications of the present results for gas reburning are discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gas reburning is a NO(x) control technique that can be applied in different combustion systems. In it, gas is injected into the furnace downstream of the primary burners to form a substoichiometric zone followed by the injection of burnout air. The variables that influence the chemistry in the reducing zone (temperature between 900 and 1450 K, reburn fuel type, stoichiometry, NO concentration and residence time), which is mainly controlled by the interactions between hydrocarbon radicals and NO, have been studied in a laboratory scale flow reactor. A significant NO reduction efficiency can be obtained with proper operating conditions. The NO destruction is closely coupled to the hydrocarbon oxidation regime, which differs depending on the hydrocarbon fuel considered, and NO is to a significant extent converted to HCN. The concentration of hydrocarbons and oxygen, and the temperature are important parameters affecting the results obtained, whereas the inlet NO concentration and the residence time only have a minor effect. The practical implications of the present results for gas reburning are discussed.
Bilbao, Rafael; Mastral, José Francisco; Aldea, María E; Ceamanos, Jesús
Kinetic study for the thermal decomposition of cellulose and pine sawdust in an air atmosphere Journal Article
In: Journal of Analytical and Applied Pyrolysis, vol. 39, no. 1, pp. 53–64, 1997, ISSN: 01652370.
@article{Bilbao1997,
title = {Kinetic study for the thermal decomposition of cellulose and pine sawdust in an air atmosphere},
author = {Rafael Bilbao and José Francisco Mastral and María E Aldea and Jesús Ceamanos},
doi = {10.1016/S0165-2370(96)00957-6},
issn = {01652370},
year = {1997},
date = {1997-01-01},
journal = {Journal of Analytical and Applied Pyrolysis},
volume = {39},
number = {1},
pages = {53--64},
publisher = {Elsevier},
abstract = {Isothermal and dynamic experiments have been performed to obtain kinetic equations for the thermal decomposition of lignocellulosic materials in an air atmosphere. The experiments were performed with cellulose, which is considered to be the main component in these materials, and pine sawdust. Equations corresponding to the different ranges of temperature and solid conversions have been obtained. A comparison has been carried out between the kinetic constant values obtained with cellulose and pine sawdust under the same operating conditions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Isothermal and dynamic experiments have been performed to obtain kinetic equations for the thermal decomposition of lignocellulosic materials in an air atmosphere. The experiments were performed with cellulose, which is considered to be the main component in these materials, and pine sawdust. Equations corresponding to the different ranges of temperature and solid conversions have been obtained. A comparison has been carried out between the kinetic constant values obtained with cellulose and pine sawdust under the same operating conditions.
Bilbao, Rafael; Alzueta, María U; Millera, Ángela; Prada, Lina
Dilution and stoichiometry effects on gas reburning: An experimental study Journal Article
In: Industrial and Engineering Chemistry Research, vol. 36, no. 6, pp. 2440–2444, 1997, ISSN: 08885885.
@article{Bilbao1997a,
title = {Dilution and stoichiometry effects on gas reburning: An experimental study},
author = {Rafael Bilbao and María U Alzueta and Ángela Millera and Lina Prada},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ie9606101},
issn = {08885885},
year = {1997},
date = {1997-01-01},
journal = {Industrial and Engineering Chemistry Research},
volume = {36},
number = {6},
pages = {2440--2444},
publisher = {American Chemical Society},
abstract = {Gas returning is a NOx reduction technique that can be applied to different combustion systems. The influence of stoichiometry and dilution effects on the efficiency of the gas reburning process has been studied from an experimental point of view at a temperature of 1100°C. Methane, ethane, and natural gas have been used as reburning fuels. The results obtained show that both stoichiometry and dilution level are very important parameters for the performance of the process. textcopyright 1997 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gas returning is a NOx reduction technique that can be applied to different combustion systems. The influence of stoichiometry and dilution effects on the efficiency of the gas reburning process has been studied from an experimental point of view at a temperature of 1100°C. Methane, ethane, and natural gas have been used as reburning fuels. The results obtained show that both stoichiometry and dilution level are very important parameters for the performance of the process. textcopyright 1997 American Chemical Society.
Alzueta, María U; Røjel, Hanne; Kristensen, Per G; Glarborg, Peter; Dam-Johansen, Kim
Laboratory study of the CO/NH3/NO/O2 system: Implications for hybrid reburn/SNCR strategies Journal Article
In: Energy and Fuels, vol. 11, no. 3, pp. 716–722, 1997, ISSN: 08870624.
@article{Alzueta1997,
title = {Laboratory study of the CO/NH3/NO/O2 system: Implications for hybrid reburn/SNCR strategies},
author = {María U Alzueta and Hanne Røjel and Per G Kristensen and Peter Glarborg and Kim Dam-Johansen},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ef960140n},
issn = {08870624},
year = {1997},
date = {1997-01-01},
journal = {Energy and Fuels},
volume = {11},
number = {3},
pages = {716--722},
publisher = {American Chemical Society},
abstract = {A laboratory study of the hybrid reburning/SNCR technique has been performed under flow reactor conditions. This technique involves the use of a selective reducing agent in the presence of combustibles (mainly CO) arising from the reburning zone. The impact of CO and O2 concentrations, NH3/NO ratio, as well as the presence of HCN has been investigated as a function of the temperature in the range 700-1300 K. The results show that CO in concentrations typical of the rich/lean transition in reburning shift the regime for NO reduction in the SNCR process to temperatures below 1000 K and cause a narrowing of the temperature window. The NO reduction potential is largely unaffected compared to conditions with low CO, and the effect varying the O2 concentration in the range 0.5-4.0% as well as of adding of HCN is found to be insignificant. Synergistic effects between reburning and SNCR are only observed in a narrow range of operating conditions with very low concentrations of CO and O2. Model predictions using a detailed reaction mechanism generally compare favorably with the experimental results. The present results indicate that a reduction of the CO level from the reburn zone is required before the SNCR chemistry is initiated. This can be obtained either by staging the burnout air or by injecting the N-agent in an aqueous solution to delay reaction.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A laboratory study of the hybrid reburning/SNCR technique has been performed under flow reactor conditions. This technique involves the use of a selective reducing agent in the presence of combustibles (mainly CO) arising from the reburning zone. The impact of CO and O2 concentrations, NH3/NO ratio, as well as the presence of HCN has been investigated as a function of the temperature in the range 700-1300 K. The results show that CO in concentrations typical of the rich/lean transition in reburning shift the regime for NO reduction in the SNCR process to temperatures below 1000 K and cause a narrowing of the temperature window. The NO reduction potential is largely unaffected compared to conditions with low CO, and the effect varying the O2 concentration in the range 0.5-4.0% as well as of adding of HCN is found to be insignificant. Synergistic effects between reburning and SNCR are only observed in a narrow range of operating conditions with very low concentrations of CO and O2. Model predictions using a detailed reaction mechanism generally compare favorably with the experimental results. The present results indicate that a reduction of the CO level from the reburn zone is required before the SNCR chemistry is initiated. This can be obtained either by staging the burnout air or by injecting the N-agent in an aqueous solution to delay reaction.
1996
Journal Articles
Bilbao, Rafael; Mastral, José Francisco; Ceamanos, Jesús; Aldea, María E
Kinetics of the thermal decomposition of polyurethane foams in nitrogen and air atmospheres Journal Article
In: Journal of Analytical and Applied Pyrolysis, vol. 37, no. 1, pp. 69–82, 1996, ISSN: 01652370.
@article{Bilbao1996a,
title = {Kinetics of the thermal decomposition of polyurethane foams in nitrogen and air atmospheres},
author = {Rafael Bilbao and José Francisco Mastral and Jesús Ceamanos and María E Aldea},
doi = {10.1016/0165-2370(96)00936-9},
issn = {01652370},
year = {1996},
date = {1996-08-01},
journal = {Journal of Analytical and Applied Pyrolysis},
volume = {37},
number = {1},
pages = {69--82},
publisher = {Elsevier},
abstract = {The kinetic equations of polyurethane foam weight loss have been determined and the influence of the atmosphere, using nitrogen and air, has been analyzed. The results of the kinetic constants obtained from isothermal and dynamic experiments have been related. A comparison between the kinetic constant values corresponding to nitrogen and air atmospheres has also been performed. The significance of using the values of solid weight that can be lost at a given temperature is analyzed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The kinetic equations of polyurethane foam weight loss have been determined and the influence of the atmosphere, using nitrogen and air, has been analyzed. The results of the kinetic constants obtained from isothermal and dynamic experiments have been related. A comparison between the kinetic constant values corresponding to nitrogen and air atmospheres has also been performed. The significance of using the values of solid weight that can be lost at a given temperature is analyzed.
Bilbao, Rafael; Mastral, José Francisco; Ceamanos, Jesús; Aldea, María E
Modelling of the pyrolysis of wet wood Journal Article
In: Journal of Analytical and Applied Pyrolysis, vol. 36, no. 1, pp. 81–97, 1996, ISSN: 01652370.
@article{Bilbao1996,
title = {Modelling of the pyrolysis of wet wood},
author = {Rafael Bilbao and José Francisco Mastral and Jesús Ceamanos and María E Aldea},
doi = {10.1016/0165-2370(95)00918-3},
issn = {01652370},
year = {1996},
date = {1996-04-01},
journal = {Journal of Analytical and Applied Pyrolysis},
volume = {36},
number = {1},
pages = {81--97},
publisher = {Elsevier},
abstract = {The influence of moisture content on the thermal decomposition of wood has been analyzed. Using wood slabs, experimental results of temperature profiles and solid conversion for different moisture contents and heat fluxes have been obtained. A mathematical model without adjustable parameters was used to calculate the temperature at different points in the sample and the average total solid conversion. Once the validity of different assumptions of the model had been analyzed, the experimental results were compared with those calculated by the model. Acceptable agreement was achieved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The influence of moisture content on the thermal decomposition of wood has been analyzed. Using wood slabs, experimental results of temperature profiles and solid conversion for different moisture contents and heat fluxes have been obtained. A mathematical model without adjustable parameters was used to calculate the temperature at different points in the sample and the average total solid conversion. Once the validity of different assumptions of the model had been analyzed, the experimental results were compared with those calculated by the model. Acceptable agreement was achieved.
1995
Journal Articles
Bilbao, Rafael; Alzueta, María U; Millera, Ángela
Experimental Study of the Influence of the Operating Variables on Natural Gas Reburning Efficiency Journal Article
In: Industrial and Engineering Chemistry Research, vol. 34, no. 12, pp. 4531–4539, 1995, ISSN: 15205045.
@article{Bilbao1995b,
title = {Experimental Study of the Influence of the Operating Variables on Natural Gas Reburning Efficiency},
author = {Rafael Bilbao and María U Alzueta and Ángela Millera},
doi = {10.1021/ie00039a047},
issn = {15205045},
year = {1995},
date = {1995-12-01},
journal = {Industrial and Engineering Chemistry Research},
volume = {34},
number = {12},
pages = {4531--4539},
abstract = {The influence of the main operating conditions in the reburning zone using natural gas on the NO, HCN, and NH3 concentrations obtained at the exit of this zone has been analyzed. Experiments with a wider range of variable values than those presented in the literature have been performed. The variables analyzed have been the temperature (1200–1500 °C), the natural gas concentration (1–4.5%) or reburning fuel fraction (0.08–0.50), the oxygen concentration at the inlet of the reburning zone (0–5%), the stoichiometric ratio in the reburning zone (0.75–1.05), the primary NO concentration (100–1200 ppm), and the gas residence time (94–280 ms). textcopyright 1995, American Chemical Society. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The influence of the main operating conditions in the reburning zone using natural gas on the NO, HCN, and NH3 concentrations obtained at the exit of this zone has been analyzed. Experiments with a wider range of variable values than those presented in the literature have been performed. The variables analyzed have been the temperature (1200–1500 °C), the natural gas concentration (1–4.5%) or reburning fuel fraction (0.08–0.50), the oxygen concentration at the inlet of the reburning zone (0–5%), the stoichiometric ratio in the reburning zone (0.75–1.05), the primary NO concentration (100–1200 ppm), and the gas residence time (94–280 ms). textcopyright 1995, American Chemical Society. All rights reserved.
Bilbao, Rafael; Alzueta, María U; Millera, Ángela; Cantín, Valentín
Experimental study and modelling of the burnout zone in the natural gas reburning process Journal Article
In: Chemical Engineering Science, vol. 50, no. 16, pp. 2579–2587, 1995, ISSN: 00092509.
@article{Bilbao1995a,
title = {Experimental study and modelling of the burnout zone in the natural gas reburning process},
author = {Rafael Bilbao and María U Alzueta and Ángela Millera and Valentín Cantín},
doi = {10.1016/0009-2509(95)00119-P},
issn = {00092509},
year = {1995},
date = {1995-08-01},
journal = {Chemical Engineering Science},
volume = {50},
number = {16},
pages = {2579--2587},
publisher = {Pergamon},
abstract = {The reburning process with natural gas is an effective technique which can be applied in existing coal combustors in order to reduce the NOx emissions. The importance of the burnout zone in this process is great, because significant amounts of CO, unburned fuel and reactive nitrogen can reach this zone. The influence of the temperature and the air excess introduced in the burnout zone on the concentration of the nitrogenous species has been studied. Experimental results have been determined of the concentrations of NO, HCN and NH3 in the exit gas for temperatures ranging between 900 and 1100°C and air excesses between 5 and 15%. An empirical correlation which fits the output NO concentration has been obtained. A simplified model has been developed to predict the output concentrations of the most interesting nitrogenous species. textcopyright 1995.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The reburning process with natural gas is an effective technique which can be applied in existing coal combustors in order to reduce the NOx emissions. The importance of the burnout zone in this process is great, because significant amounts of CO, unburned fuel and reactive nitrogen can reach this zone. The influence of the temperature and the air excess introduced in the burnout zone on the concentration of the nitrogenous species has been studied. Experimental results have been determined of the concentrations of NO, HCN and NH3 in the exit gas for temperatures ranging between 900 and 1100°C and air excesses between 5 and 15%. An empirical correlation which fits the output NO concentration has been obtained. A simplified model has been developed to predict the output concentrations of the most interesting nitrogenous species. textcopyright 1995.
Bilbao, Rafael; Arauzo, Jesús; Salvador, María L
Kinetics and Modeling of Gas Formation in the Thermal Decomposition of Powdery Cellulose and Pine Sawdust Journal Article
In: Industrial and Engineering Chemistry Research, vol. 34, no. 3, pp. 786–793, 1995, ISSN: 15205045.
@article{Bilbao1995,
title = {Kinetics and Modeling of Gas Formation in the Thermal Decomposition of Powdery Cellulose and Pine Sawdust},
author = {Rafael Bilbao and Jesús Arauzo and María L Salvador},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ie00042a010},
issn = {15205045},
year = {1995},
date = {1995-03-01},
journal = {Industrial and Engineering Chemistry Research},
volume = {34},
number = {3},
pages = {786--793},
publisher = {American Chemical Society},
abstract = {The formation of different gases in the thermal decomposition of cellulose and pine sawdust has been studied. The kinetic constants of CO2 and H2 formation in cellulose decomposition have been determined from results obtained in isothermal experiments. These kinetic constants have been taken as representative of pine sawdust decomposition at T > 292 °C, and values for lower temperatures have been obtained from isothermal experiments performed with pine sawdust. For both materials, a simple model without adjustable parameters has been applied that allows us to calculate the local temperature, solid conversion, and yield of each gas. The results obtained in dynamic experiments with heating rates ranging between 2 and 53 °C/min have been compared with the theoretical results, and an acceptable agreement has been achieved. textcopyright 1995, American Chemical Society. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The formation of different gases in the thermal decomposition of cellulose and pine sawdust has been studied. The kinetic constants of CO2 and H2 formation in cellulose decomposition have been determined from results obtained in isothermal experiments. These kinetic constants have been taken as representative of pine sawdust decomposition at T > 292 °C, and values for lower temperatures have been obtained from isothermal experiments performed with pine sawdust. For both materials, a simple model without adjustable parameters has been applied that allows us to calculate the local temperature, solid conversion, and yield of each gas. The results obtained in dynamic experiments with heating rates ranging between 2 and 53 °C/min have been compared with the theoretical results, and an acceptable agreement has been achieved. textcopyright 1995, American Chemical Society. All rights reserved.
Technical Reports
Bilbao, Rafael; Alzueta, María U; Millera, Ángela; Duarte, Mario
Simplified Kinetic Model of the Chemistry in the Reburning Zone Using Natural Gas Technical Report
1995.
@techreport{Bilbao1995c,
title = {Simplified Kinetic Model of the Chemistry in the Reburning Zone Using Natural Gas},
author = {Rafael Bilbao and María U Alzueta and Ángela Millera and Mario Duarte},
url = {https://pubs.acs.org/sharingguidelines},
year = {1995},
date = {1995-01-01},
booktitle = {Ind. Eng. Chem. Res},
volume = {34},
pages = {4540--4548},
abstract = {A simplified kinetic model of the chemistry of NO reduction by the action of natural gas has been obtained. This model consists of 87 elementary reactions and 38 chemical species. It takes into account the natural gas decomposition and oxidation, the interaction between NO and hydrocarbons, and the conversion of the intermediate nitrogenous species. The concentrations of the species calculated with the model have been compared with those obtained experimentally using the operating conditions for which a good efficiency in the rebuming zone is achieved. The comparison between the theoretical and experimental data of NO, HCN, CO, and CO2 has been extended to the results obtained over a wide range of values of the operating conditions in the reburning zone.},
keywords = {},
pubstate = {published},
tppubtype = {techreport}
}
A simplified kinetic model of the chemistry of NO reduction by the action of natural gas has been obtained. This model consists of 87 elementary reactions and 38 chemical species. It takes into account the natural gas decomposition and oxidation, the interaction between NO and hydrocarbons, and the conversion of the intermediate nitrogenous species. The concentrations of the species calculated with the model have been compared with those obtained experimentally using the operating conditions for which a good efficiency in the rebuming zone is achieved. The comparison between the theoretical and experimental data of NO, HCN, CO, and CO2 has been extended to the results obtained over a wide range of values of the operating conditions in the reburning zone.
1994
Journal Articles
Bilbao, Rafael; Salvador, María L; Arauzo, Jesús
Influence of the heating rate on the temperature profiles and on the conversion rate of powdery cellulose and pine sawdust Journal Article
In: Journal of Analytical and Applied Pyrolysis, vol. 30, no. 2, pp. 145–159, 1994, ISSN: 01652370.
@article{Bilbao1994,
title = {Influence of the heating rate on the temperature profiles and on the conversion rate of powdery cellulose and pine sawdust},
author = {Rafael Bilbao and María L Salvador and Jesús Arauzo},
doi = {10.1016/0165-2370(94)00809-4},
issn = {01652370},
year = {1994},
date = {1994-12-01},
journal = {Journal of Analytical and Applied Pyrolysis},
volume = {30},
number = {2},
pages = {145--159},
publisher = {Elsevier},
abstract = {An experimental study of the thermal decomposition of powdered cellulose and pine sawdust has been performed. The influence of the heating rate on the temperature profiles in the sample and on the solid conversion rate has been studied. A mathematical model without adjustable parameters has been used to calculate the temperature at different points in the solid bed and the average total solid conversion. The experimental results have been compared with those calculated by the model. A good agreement has been obtained for sawdust. Some differences are observed for cellulose at high heating rates, and the influence of the thermal conductivity and the reaction heat on the results has been analysed. textcopyright 1994.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An experimental study of the thermal decomposition of powdered cellulose and pine sawdust has been performed. The influence of the heating rate on the temperature profiles in the sample and on the solid conversion rate has been studied. A mathematical model without adjustable parameters has been used to calculate the temperature at different points in the solid bed and the average total solid conversion. The experimental results have been compared with those calculated by the model. A good agreement has been obtained for sawdust. Some differences are observed for cellulose at high heating rates, and the influence of the thermal conductivity and the reaction heat on the results has been analysed. textcopyright 1994.
Bilbao, Rafael; Millera, Ángela; Alzueta, María U
Influence of the Temperature and Oxygen Concentration on NOx Reduction in the Natural Gas Reburning Process Journal Article
In: Industrial and Engineering Chemistry Research, vol. 33, no. 11, pp. 2846–2852, 1994, ISSN: 15205045.
@article{Bilbao1994a,
title = {Influence of the Temperature and Oxygen Concentration on NOx Reduction in the Natural Gas Reburning Process},
author = {Rafael Bilbao and Ángela Millera and María U Alzueta},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ie00035a039},
issn = {15205045},
year = {1994},
date = {1994-11-01},
journal = {Industrial and Engineering Chemistry Research},
volume = {33},
number = {11},
pages = {2846--2852},
publisher = {American Chemical Society},
abstract = {The reburning process with natural gas is an effective technique which can be applied in existing coal combustors in order to reduce the NOx emissions. The influence of the reburning temperature (1200–1500 °C) and the oxygen concentration coming from the primary combustion zone (0–5%) have been studied. Experimental results of NO, HCN, NH3, CO, CO2, and CH4 concentrations in the exit gas have been determined. The influence of the natural gas decomposition on these results has been analyzed. The experimental trends obtained have been compared with those calculated with the model of Kilpinen et al. (1992). textcopyright 1994, American Chemical Society. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The reburning process with natural gas is an effective technique which can be applied in existing coal combustors in order to reduce the NOx emissions. The influence of the reburning temperature (1200–1500 °C) and the oxygen concentration coming from the primary combustion zone (0–5%) have been studied. Experimental results of NO, HCN, NH3, CO, CO2, and CH4 concentrations in the exit gas have been determined. The influence of the natural gas decomposition on these results has been analyzed. The experimental trends obtained have been compared with those calculated with the model of Kilpinen et al. (1992). textcopyright 1994, American Chemical Society. All rights reserved.
Arauzo, Jesús; Radlein, D; Piskorz, J; Scott, D S
A New Catalyst for the Catalytic Gasification of Biomass Journal Article
In: Energy and Fuels, vol. 8, no. 6, pp. 1192–1196, 1994, ISSN: 15205029.
@article{Arauzo1994,
title = {A New Catalyst for the Catalytic Gasification of Biomass},
author = {Jesús Arauzo and D Radlein and J Piskorz and D S Scott},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ef00048a005},
issn = {15205029},
year = {1994},
date = {1994-11-01},
journal = {Energy and Fuels},
volume = {8},
number = {6},
pages = {1192--1196},
publisher = {American Chemical Society},
abstract = {Various kinds of catalysts are being developed and tested for the pyrolytic gasification of biomass using the Waterloo Fast Pyrolysis Process (WFPP) technology. The present report describes gasification tests with wood in a continuous bench scale fluidized bed reactor but with no added air or oxygen in the region of 500–700 °C and at short gas contact times, using a crystalline nickel aluminate catalyst. The objective was to determine the most appropriate operating conditions for this catalyst and its performance for the production of a synthesis gas in high yields. Experiments were carried out with this catalyst in both inert and reactive gasification media, but without any oxygen or air addition. The results show the influence of the catalyst on the nature of the gasification products and the effect of operating variables. Gas compositions are given for typical WFPP operating conditions. Evidence is presented which indicates that the gasification mechanism is a fast thermal pyrolysis followed by catalytic reforming of the vapors with a high yield of synthesis gas. textcopyright 1994, American Chemical Society. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Various kinds of catalysts are being developed and tested for the pyrolytic gasification of biomass using the Waterloo Fast Pyrolysis Process (WFPP) technology. The present report describes gasification tests with wood in a continuous bench scale fluidized bed reactor but with no added air or oxygen in the region of 500–700 °C and at short gas contact times, using a crystalline nickel aluminate catalyst. The objective was to determine the most appropriate operating conditions for this catalyst and its performance for the production of a synthesis gas in high yields. Experiments were carried out with this catalyst in both inert and reactive gasification media, but without any oxygen or air addition. The results show the influence of the catalyst on the nature of the gasification products and the effect of operating variables. Gas compositions are given for typical WFPP operating conditions. Evidence is presented which indicates that the gasification mechanism is a fast thermal pyrolysis followed by catalytic reforming of the vapors with a high yield of synthesis gas. textcopyright 1994, American Chemical Society. All rights reserved.
García-Bacaicoa, Pedro; Bilbao, Rafael; Arauzo, Jesús; Salvador, María L
Scale-up of downdraft moving bed gasifiers (25-300 kg/h) – Design, experimental aspects and results Journal Article
In: Bioresource Technology, vol. 48, no. 3, pp. 229–235, 1994, ISSN: 09608524.
@article{Garcia-Bacaicoa1994,
title = {Scale-up of downdraft moving bed gasifiers (25-300 kg/h) - Design, experimental aspects and results},
author = {Pedro García-Bacaicoa and Rafael Bilbao and Jesús Arauzo and María L Salvador},
doi = {10.1016/0960-8524(94)90151-1},
issn = {09608524},
year = {1994},
date = {1994-01-01},
journal = {Bioresource Technology},
volume = {48},
number = {3},
pages = {229--235},
publisher = {Elsevier},
abstract = {Two installations with different biomass processing capacities (25-50 and 200-300 kg/h) were designed and constructed for air gasification of lignocellulosic biomass. This paper describes both installations as well as the experimental procedure. The influence of operating conditions on the amount and quality of products was determined. The results obtained from processing forestry waste are analysed. Values above 90% for mass conversion efficiency and over 70% for cold gas efficiency were reached. textcopyright 1994.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Two installations with different biomass processing capacities (25-50 and 200-300 kg/h) were designed and constructed for air gasification of lignocellulosic biomass. This paper describes both installations as well as the experimental procedure. The influence of operating conditions on the amount and quality of products was determined. The results obtained from processing forestry waste are analysed. Values above 90% for mass conversion efficiency and over 70% for cold gas efficiency were reached. textcopyright 1994.
1993
Journal Articles
Bilbao, Rafael; Salvador, María L; García-Bacaicoa, Pedro; Arauzo, Jesús
Solid weight loss in the thermal decomposition of cellulose and pine sawdust Journal Article
In: Journal of Analytical and Applied Pyrolysis, vol. 24, no. 3, pp. 257–271, 1993, ISSN: 01652370.
@article{Bilbao1993a,
title = {Solid weight loss in the thermal decomposition of cellulose and pine sawdust},
author = {Rafael Bilbao and María L Salvador and Pedro García-Bacaicoa and Jesús Arauzo},
doi = {10.1016/0165-2370(93)85005-J},
issn = {01652370},
year = {1993},
date = {1993-02-01},
journal = {Journal of Analytical and Applied Pyrolysis},
volume = {24},
number = {3},
pages = {257--271},
publisher = {Elsevier},
abstract = {An experimental study of the thermal decomposition of powdered lignocellulosic biomass was performed in a macrobalance system. Weight loss and temperature profiles in the bed for different heating rates were determined using mainly cellulose and pine sawdust. Some experiments with xylan and lignin were also carried out. A simple model was used to calculate weight loss and temperature at different points. An average temperature allows comparison of the results obtained. textcopyright 1993.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An experimental study of the thermal decomposition of powdered lignocellulosic biomass was performed in a macrobalance system. Weight loss and temperature profiles in the bed for different heating rates were determined using mainly cellulose and pine sawdust. Some experiments with xylan and lignin were also carried out. A simple model was used to calculate weight loss and temperature at different points. An average temperature allows comparison of the results obtained. textcopyright 1993.