1994
Journal Articles
Menéndez, Miguel; Braña, Alfredo F
VARIATIONS IN THE POROUS STRUCTURE OF A CR2O3/AL2O3 CATALYST BY COKE DEPOSITION Journal Article
En: Canadian Journal of Chemical Engineering, vol. 72, pp. 926-928, 1994.
@article{nokey,
title = {VARIATIONS IN THE POROUS STRUCTURE OF A CR2O3/AL2O3 CATALYST BY COKE DEPOSITION},
author = {Miguel Menéndez and Alfredo F Braña},
url = {https://api.semanticscholar.org/CorpusID:95801861},
year = {1994},
date = {1994-01-01},
journal = {Canadian Journal of Chemical Engineering},
volume = {72},
pages = {926-928},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Books
Santos, A.; Finol, C.; Coronas, J.; Lafarga, D.; Menendez, M.; Santamaría, J.
1994, ISSN: 01672991.
@book{Santos1994c,
title = {Catalytic reactor engineering for the oxidative coupling of methane. use of a fluidized bed and of a ceramic membrane reactor},
author = {A. Santos and C. Finol and J. Coronas and D. Lafarga and M. Menendez and J. Santamaría},
doi = {10.1016/S0167-2991(08)63430-8},
issn = {01672991},
year = {1994},
date = {1994-01-01},
journal = {Studies in Surface Science and Catalysis},
volume = {82},
issue = {C},
abstract = {A study has been carried out of fluidized bed reactors and of membrane reactors as contactors for methane oxidative coupling. Both reactors are capable of providing a low oxygen concentration in the gas phase in contact with the catalyst, which can be expected to increase the selectivity to hydrocarbons in the system studied. Other operational characteristics such as temperature gradients within the reactor are also discussed. © 1994, Elsevier Science B.V.},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
A study has been carried out of fluidized bed reactors and of membrane reactors as contactors for methane oxidative coupling. Both reactors are capable of providing a low oxygen concentration in the gas phase in contact with the catalyst, which can be expected to increase the selectivity to hydrocarbons in the system studied. Other operational characteristics such as temperature gradients within the reactor are also discussed. © 1994, Elsevier Science B.V.
1993
Journal Articles
Peña, J. A.; Monzón, A.; Santamaría, J.; Fierro, J. L. G.
Coking kinetics of fresh and thermally aged commercial Cr2O3/Al2O3 catalyst Journal Article
En: Applied Catalysis A: General, vol. 101, iss. 2, pp. 185-198, 1993, ISSN: 0926-860X.
@article{nokey,
title = {Coking kinetics of fresh and thermally aged commercial Cr2O3/Al2O3 catalyst},
author = {J. A. Peña and A. Monzón and J. Santamaría and J. L. G. Fierro},
doi = {10.1016/0926-860X(93)80268-U},
issn = {0926-860X},
year = {1993},
date = {1993-01-01},
journal = {Applied Catalysis A: General},
volume = {101},
issue = {2},
pages = {185-198},
publisher = {Elsevier},
abstract = {The coking behaviour of fresh and of thermally aged Cr2O3/Al2O3 catalysts has been studied during the dehydrogenation of n-butene to butadiene using a thermogravimetric system. The results show that catalyst aging decreases considerably the rate of the main reaction, but also the rate of coking. As a consequence, the dehydrogenation rates obtained after a certain reaction time with aged catalyst were higher than those for fresh catalyst. The analysis of the coking kinetics on fresh and on thermally aged catalyst and the X-ray photoelectron spectroscopy results obtained on both samples suggest that the deactivation mechanism is not changed by the aging process, and that the main effect of aging is to reduce the number of sites available on the surface for the main and coking reactions. © 1993.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The coking behaviour of fresh and of thermally aged Cr2O3/Al2O3 catalysts has been studied during the dehydrogenation of n-butene to butadiene using a thermogravimetric system. The results show that catalyst aging decreases considerably the rate of the main reaction, but also the rate of coking. As a consequence, the dehydrogenation rates obtained after a certain reaction time with aged catalyst were higher than those for fresh catalyst. The analysis of the coking kinetics on fresh and on thermally aged catalyst and the X-ray photoelectron spectroscopy results obtained on both samples suggest that the deactivation mechanism is not changed by the aging process, and that the main effect of aging is to reduce the number of sites available on the surface for the main and coking reactions. © 1993.
Peña, J. A.; Monzón, A.; Santamaría, J.
Deactivation by Coke of a Cr2O3/Al2O3 Catalyst During Butene Dehydrogenation Journal Article
En: Journal of Catalysis, vol. 142, iss. 1, pp. 59-69, 1993, ISSN: 0021-9517.
@article{nokey,
title = {Deactivation by Coke of a Cr2O3/Al2O3 Catalyst During Butene Dehydrogenation},
author = {J. A. Peña and A. Monzón and J. Santamaría},
doi = {10.1006/JCAT.1993.1189},
issn = {0021-9517},
year = {1993},
date = {1993-01-01},
journal = {Journal of Catalysis},
volume = {142},
issue = {1},
pages = {59-69},
publisher = {Academic Press},
abstract = {The coking data obtained during the dehydragenation of n-butene on a Cr2O3/Al2O3 catalyst have been successfully fitted using a model which considers simultaneously coke depositian directly on the surface (monolayer coke) and on multiple layers. The variation of the monolayer and multiple-layer coking rates with time, temperature, and hydrogen partial pressure have been investigated. The results obtained in this work show that the relevant deactivation variable far this system is the amount of monolayer coke, rather than the total coke content of the catalyst. © 1993 Academic Press, Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The coking data obtained during the dehydragenation of n-butene on a Cr2O3/Al2O3 catalyst have been successfully fitted using a model which considers simultaneously coke depositian directly on the surface (monolayer coke) and on multiple layers. The variation of the monolayer and multiple-layer coking rates with time, temperature, and hydrogen partial pressure have been investigated. The results obtained in this work show that the relevant deactivation variable far this system is the amount of monolayer coke, rather than the total coke content of the catalyst. © 1993 Academic Press, Inc.
1992
Journal Articles
Herguido, J; Corella, J; González-Saiz, J
Steam gasification of lignocellulosic residues in a fluidized bed at a small pilot scale. Effect of the type of feedstock Journal Article
En: Industrial and Engineering Chemistry Research, 1992.
@article{Herguido1992,
title = {Steam gasification of lignocellulosic residues in a fluidized bed at a small pilot scale. Effect of the type of feedstock},
author = {J Herguido and J Corella and J González-Saiz},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0026864228&partnerID=MN8TOARS},
year = {1992},
date = {1992-01-01},
journal = {Industrial and Engineering Chemistry Research},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Santamaría, J.; Menéndez, M.; Peña, J. A.; Barahona, J. I.
Methane oxidative coupling in fixed bed catalytic reactors with a distributed oxygen feed. A simulation study Journal Article
En: Catalysis Today, vol. 13, iss. 2-3, 1992, ISSN: 09205861.
@article{nokey,
title = {Methane oxidative coupling in fixed bed catalytic reactors with a distributed oxygen feed. A simulation study},
author = {J. Santamaría and M. Menéndez and J. A. Peña and J. I. Barahona},
doi = {10.1016/0920-5861(92)80160-O},
issn = {09205861},
year = {1992},
date = {1992-01-01},
journal = {Catalysis Today},
volume = {13},
issue = {2-3},
abstract = {A simulation study has been carried out of methane oxidative coupling in a fixed bed catalytic reactor with a distributed oxygen feed. To this end, a lumped kinetic model which takes into account 4 main species, namely CH 4 , O 2 , CO x ( CO and CO 2 ) and C 2 (ethane and ethylene) has been used coupled with a pseudohomogeneous plug flow reactor model. The model contemplates several oxygen inputs along the reactor length, and also the possibility of heat exchange between the reactor and a cooling medium. The simulation yields the variation of temperature along the bed, together with the concentration profiles for the species considered. The results indicate that a distributed oxygen feed may significantly improve the yield to hydrocarbons in the oxidative coupling process. © 1992.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A simulation study has been carried out of methane oxidative coupling in a fixed bed catalytic reactor with a distributed oxygen feed. To this end, a lumped kinetic model which takes into account 4 main species, namely CH 4 , O 2 , CO x ( CO and CO 2 ) and C 2 (ethane and ethylene) has been used coupled with a pseudohomogeneous plug flow reactor model. The model contemplates several oxygen inputs along the reactor length, and also the possibility of heat exchange between the reactor and a cooling medium. The simulation yields the variation of temperature along the bed, together with the concentration profiles for the species considered. The results indicate that a distributed oxygen feed may significantly improve the yield to hydrocarbons in the oxidative coupling process. © 1992.
1991
Journal Articles
Royo, C.; Menéndez, M.; Santamaría, J.
Kinetics of catalyst regeneration by coke combustion. I. Increased reaction rate due to the presence of chromium Journal Article
En: Reaction Kinetics & Catalysis Letters, vol. 44, iss. 2, 1991, ISSN: 01331736.
@article{Royo1991,
title = {Kinetics of catalyst regeneration by coke combustion. I. Increased reaction rate due to the presence of chromium},
author = {C. Royo and M. Menéndez and J. Santamaría},
doi = {10.1007/BF02073013},
issn = {01331736},
year = {1991},
date = {1991-01-01},
journal = {Reaction Kinetics & Catalysis Letters},
volume = {44},
issue = {2},
abstract = {A kinetic study has been carried out of the regeneration of a commercial Cr 2 O 3 /Al 2 O 3 catalyst by coke combustion. The results obtained show that the reaction rate is several orders of magnitude higher than that obtained on catalysts without transition metals. © 1991 Akadémiai Kiadó.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A kinetic study has been carried out of the regeneration of a commercial Cr 2 O 3 /Al 2 O 3 catalyst by coke combustion. The results obtained show that the reaction rate is several orders of magnitude higher than that obtained on catalysts without transition metals. © 1991 Akadémiai Kiadó.
Bilbao, R.; Lezaun, J.; Menéndez, M.; Izquierdo, M. T.
Segregation of straw/sand mixtures in fluidized beds in non-steady state Journal Article
En: Powder Technology, vol. 68, iss. 1, 1991, ISSN: 00325910.
@article{Bilbao1991,
title = {Segregation of straw/sand mixtures in fluidized beds in non-steady state},
author = {R. Bilbao and J. Lezaun and M. Menéndez and M. T. Izquierdo},
doi = {10.1016/0032-5910(91)80061-M},
issn = {00325910},
year = {1991},
date = {1991-01-01},
journal = {Powder Technology},
volume = {68},
issue = {1},
abstract = {A model predicting the concentration profiles of straw/sand mixtures in non-steady-state fluidized beds is presented. The model is based on the mechanisms of mixing-segregation developed for these mixtures in steady state. A method to solve the mass balances is shown. Satisfactory agreement is obtained between the experimental results and the predictions of the model. The variation of mixing index with the time is also shown. © 1991.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A model predicting the concentration profiles of straw/sand mixtures in non-steady-state fluidized beds is presented. The model is based on the mechanisms of mixing-segregation developed for these mixtures in steady state. A method to solve the mass balances is shown. Satisfactory agreement is obtained between the experimental results and the predictions of the model. The variation of mixing index with the time is also shown. © 1991.
Lafarga, D.; Royo, C.; Monzón, A.; Menéndez, M.; Santamaría, J.
Kinetics of catalyst regeneration by coke combustion. II. Influence of temperature rise in the catalyst particles Journal Article
En: Reaction Kinetics & Catalysis Letters, vol. 44, iss. 2, 1991, ISSN: 01331736.
@article{Lafarga1991,
title = {Kinetics of catalyst regeneration by coke combustion. II. Influence of temperature rise in the catalyst particles},
author = {D. Lafarga and C. Royo and A. Monzón and M. Menéndez and J. Santamaría},
doi = {10.1007/BF02072990},
issn = {01331736},
year = {1991},
date = {1991-01-01},
journal = {Reaction Kinetics & Catalysis Letters},
volume = {44},
issue = {2},
abstract = {A grain-pellet model has been used to study the effect of high reaction rates upon the temperature profiles developed during regeneration of coked catalyst particles. The possibility of falsification of kinetic data is discussed in view of the results obtained. © 1991 Akadémiai Kiadó.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A grain-pellet model has been used to study the effect of high reaction rates upon the temperature profiles developed during regeneration of coked catalyst particles. The possibility of falsification of kinetic data is discussed in view of the results obtained. © 1991 Akadémiai Kiadó.
Agorreta, E. L.; Peña, J. A.; Santamaria, J.; Monzón, A.
A Kinetic Model for Activation-Deactivation Processes in Solid Catalysts Journal Article
En: Industrial and Engineering Chemistry Research, vol. 30, iss. 1, 1991, ISSN: 15205045.
@article{Agorreta1991,
title = {A Kinetic Model for Activation-Deactivation Processes in Solid Catalysts},
author = {E. L. Agorreta and J. A. Peña and J. Santamaria and A. Monzón},
doi = {10.1021/ie00049a017},
issn = {15205045},
year = {1991},
date = {1991-01-01},
journal = {Industrial and Engineering Chemistry Research},
volume = {30},
issue = {1},
abstract = {A kinetic model is proposed to describe the activation-deactivation phenomena taking place simultaneously with the main reaction on a catalytic surface. Potentially active sites are transformed into active sites by the activation process. Simultaneously, catalyst deactivation gives rise to deactivated sites from active sites. The model presented considers jointly the activation and deactivation processes on the catalyst surface. When activation processes are present, this is a more rigorous alternative to studies that only take into account catalyst deactivation. Kinetic expressions have been obtained for activation processes coupled with reversible and irreversible deactivation, and a study of the influence of the different kinetic parameters has been carried out. Finally, the model developed has been applied to previous literature data on n-butane isomerization on an aluminum chloride/sulfonic acid resin. © 1991, American Chemical Society. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A kinetic model is proposed to describe the activation-deactivation phenomena taking place simultaneously with the main reaction on a catalytic surface. Potentially active sites are transformed into active sites by the activation process. Simultaneously, catalyst deactivation gives rise to deactivated sites from active sites. The model presented considers jointly the activation and deactivation processes on the catalyst surface. When activation processes are present, this is a more rigorous alternative to studies that only take into account catalyst deactivation. Kinetic expressions have been obtained for activation processes coupled with reversible and irreversible deactivation, and a study of the influence of the different kinetic parameters has been carried out. Finally, the model developed has been applied to previous literature data on n-butane isomerization on an aluminum chloride/sulfonic acid resin. © 1991, American Chemical Society. All rights reserved.
Books
Gregori, L.; Desmay, A.; Agorreta, E.; Menendez, M.; Monzon, A.
Thioresistance of reforming catalysts in the presence of coking Book
1991, ISSN: 01672991.
@book{Gregori1991,
title = {Thioresistance of reforming catalysts in the presence of coking},
author = {L. Gregori and A. Desmay and E. Agorreta and M. Menendez and A. Monzon},
doi = {10.1016/S0167-2991(08)62687-7},
issn = {01672991},
year = {1991},
date = {1991-01-01},
journal = {Studies in Surface Science and Catalysis},
volume = {68},
issue = {C},
abstract = {A previously developed kinetic model has been used for the analysis of catalyst deactivation by sulphur when a second deactivating cause is present. The results obtained in the application of the model to previous data have been used to characterize the thioresistance of Pt, Pt-Re and Pt-Ir catalysts supported on alumina. Several parameters are introduced which form the basis of thioresistance scales. © 1991, Elsevier Science & Technology. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
A previously developed kinetic model has been used for the analysis of catalyst deactivation by sulphur when a second deactivating cause is present. The results obtained in the application of the model to previous data have been used to characterize the thioresistance of Pt, Pt-Re and Pt-Ir catalysts supported on alumina. Several parameters are introduced which form the basis of thioresistance scales. © 1991, Elsevier Science & Technology. All rights reserved.
Blasco, V.; Royo, C.; Menendez, M.; Santamaria, J.; Fierro, J. L.
Non-uniform sintering in oxyregeneration of fixed bed catalytic reactors Book
1991, ISSN: 01672991.
@book{Blasco1991,
title = {Non-uniform sintering in oxyregeneration of fixed bed catalytic reactors},
author = {V. Blasco and C. Royo and M. Menendez and J. Santamaria and J. L. Fierro},
doi = {10.1016/S0167-2991(08)62693-2},
issn = {01672991},
year = {1991},
date = {1991-01-01},
journal = {Studies in Surface Science and Catalysis},
volume = {68},
issue = {C},
abstract = {An experimental study of the possibility of non-uniform sintering during oxidative regeneration of fixed bed catalytic reactors has been carried out. Both kinetic measurements and XPS results show that a different degree of sintering can be expected in catalyst particles sampled at different reactor positions. © 1991, Elsevier Science & Technology. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
An experimental study of the possibility of non-uniform sintering during oxidative regeneration of fixed bed catalytic reactors has been carried out. Both kinetic measurements and XPS results show that a different degree of sintering can be expected in catalyst particles sampled at different reactor positions. © 1991, Elsevier Science & Technology. All rights reserved.
1988
Journal Articles
Bilbao, R.; Lezaun, J.; Menéndez, M.; Abanades, J. C.
Model of mixing-segregation for straw/sand mixtures in fluidized beds Journal Article
En: Powder Technology, vol. 56, iss. 3, 1988, ISSN: 00325910.
@article{Bilbao1988,
title = {Model of mixing-segregation for straw/sand mixtures in fluidized beds},
author = {R. Bilbao and J. Lezaun and M. Menéndez and J. C. Abanades},
doi = {10.1016/0032-5910(88)80026-3},
issn = {00325910},
year = {1988},
date = {1988-01-01},
journal = {Powder Technology},
volume = {56},
issue = {3},
abstract = {When a sand/straw mixture (HSF/LBP type) is fluidized with air, a high degree of segregation can appear, with the sand settling at the bottom of the bed (jetsam) and the straw rising to the top (flotsam). A new model, based on that of Gibilaro and Rowe but accounting for the particular characteristics of the solids used, has been developed. Reasonable agreement with experimental data has been obtained. The values of the parameters that fit the experimental results for a wide range of conditions are obtained. © 1988.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
When a sand/straw mixture (HSF/LBP type) is fluidized with air, a high degree of segregation can appear, with the sand settling at the bottom of the bed (jetsam) and the straw rising to the top (flotsam). A new model, based on that of Gibilaro and Rowe but accounting for the particular characteristics of the solids used, has been developed. Reasonable agreement with experimental data has been obtained. The values of the parameters that fit the experimental results for a wide range of conditions are obtained. © 1988.
1986
Journal Articles
Corella, J.; Menéndez, M.
En: Chemical Engineering Science, vol. 41, iss. 7, 1986, ISSN: 00092509.
@article{Corella1986,
title = {The modelling of the kinetics of deactivation of monofunctional catalysts with an acid strength distribution in their non-homogeneous surface. Application to the deactivation of commercial catalysts in the FCC process},
author = {J. Corella and M. Menéndez},
doi = {10.1016/0009-2509(86)87061-0},
issn = {00092509},
year = {1986},
date = {1986-01-01},
journal = {Chemical Engineering Science},
volume = {41},
issue = {7},
abstract = {A model for the kinetics of the deactivation of monofunctional catalysts with a heterogeneous or non-uniform active surface is presented. This model is based on previous work by Butt et al. (1978, Chem. Engng Sci. 33, 1321) and starts from the consideration of a function of strength distribution for the active sites. Four types of strength distribution are considered. In the model time-on-stream is used as the independent variable. The influence of the values of the parameters of the catalyst surface on the activity-time curves and the parametric sensitivity of the model are analysed. With the consideration of the non-uniformity of the catalyst surface developed in this model one can adjust perfectly well the data of deactivation of commercial catalysts in the cracking of gas oils and the empirical correlation of a general character proposed by Pacheco and Petersen (1984a, J. Catalysis 86, 75) for a large variety of processes and catalysts. © 1985.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A model for the kinetics of the deactivation of monofunctional catalysts with a heterogeneous or non-uniform active surface is presented. This model is based on previous work by Butt et al. (1978, Chem. Engng Sci. 33, 1321) and starts from the consideration of a function of strength distribution for the active sites. Four types of strength distribution are considered. In the model time-on-stream is used as the independent variable. The influence of the values of the parameters of the catalyst surface on the activity-time curves and the parametric sensitivity of the model are analysed. With the consideration of the non-uniformity of the catalyst surface developed in this model one can adjust perfectly well the data of deactivation of commercial catalysts in the cracking of gas oils and the empirical correlation of a general character proposed by Pacheco and Petersen (1984a, J. Catalysis 86, 75) for a large variety of processes and catalysts. © 1985.