Documents disponibles écrits par cet auteur

Carbonation of CaO - based sorbents enhanced by steam addition / Vasilije Manovic in Industrial & engineering chemistry research, Vol. 49 N° 19 (Octobre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9105–9110 Titre : Carbonation of CaO - based sorbents enhanced by steam addition Type de document : texte imprimé Auteurs : Vasilije Manovic, Auteur ; Edward J. Anthony, Auteur Année de publication : 2010 Article en page(s) : pp. 9105–9110 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbonation  Combustion  Thermogravimetric  analyzer Résumé : The carbonation reaction has recently been intensively investigated as a means of CO2 capture from gas mixtures such as flue gas produced during fossil fuel combustion. Unfortunately, this gas−solid reaction is limited due to formation of the solid product (CaCO3) at the reacting surface and sintering, all of which reduce the carrying capacity of the sorbent. In this work the enhancement of carbonation conversion by means of steam addition to the carbonating gas was studied. Seven limestones of different origin and composition as well as one synthetic sorbent (calcium aluminate pellets) were tested. A thermogravimetric analyzer (TGA) was employed for the carbonation tests at different temperatures (350−800 °C) in a gas mixture containing typically 20% CO2 and 10 or 20% H2O(g). The samples tested were calcined under an N2 (800 °C) or CO2 (950 °C) atmosphere to explore the influence of different levels of sample sintering, and the results obtained were compared with those seen for carbonation in dry (no steam) gas mixtures. The morphology of samples after carbonation under different conditions was examined by a scanning electron microscope (SEM). It was found that carbonation is enhanced by steam, but this is more pronounced at lower temperatures and for more sintered samples. With increasing temperature and carbonation time, the enhancement of carbonation becomes negligible because the conversion reaches a “maximum” value (75−80% for samples calcined in N2) even without steam. Carbonation of samples calcined in CO2 is enhanced at different levels depending on the sorbent tested. The shape of carbonation profiles and morphology of carbonated samples show that steam enhances solid state diffusion and, consequently, conversion during carbonation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101352s [article] Carbonation of CaO - based sorbents enhanced by steam addition [texte imprimé] / Vasilije Manovic, Auteur ; Edward J. Anthony, Auteur . - 2010 . - pp. 9105–9110. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9105–9110 Mots-clés : Carbonation  Combustion  Thermogravimetric  analyzer Résumé : The carbonation reaction has recently been intensively investigated as a means of CO2 capture from gas mixtures such as flue gas produced during fossil fuel combustion. Unfortunately, this gas−solid reaction is limited due to formation of the solid product (CaCO3) at the reacting surface and sintering, all of which reduce the carrying capacity of the sorbent. In this work the enhancement of carbonation conversion by means of steam addition to the carbonating gas was studied. Seven limestones of different origin and composition as well as one synthetic sorbent (calcium aluminate pellets) were tested. A thermogravimetric analyzer (TGA) was employed for the carbonation tests at different temperatures (350−800 °C) in a gas mixture containing typically 20% CO2 and 10 or 20% H2O(g). The samples tested were calcined under an N2 (800 °C) or CO2 (950 °C) atmosphere to explore the influence of different levels of sample sintering, and the results obtained were compared with those seen for carbonation in dry (no steam) gas mixtures. The morphology of samples after carbonation under different conditions was examined by a scanning electron microscope (SEM). It was found that carbonation is enhanced by steam, but this is more pronounced at lower temperatures and for more sintered samples. With increasing temperature and carbonation time, the enhancement of carbonation becomes negligible because the conversion reaches a “maximum” value (75−80% for samples calcined in N2) even without steam. Carbonation of samples calcined in CO2 is enhanced at different levels depending on the sorbent tested. The shape of carbonation profiles and morphology of carbonated samples show that steam enhances solid state diffusion and, consequently, conversion during carbonation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101352s

CO2 carrying behavior of calcium aluminate pellets under high-temperature/high-CO2 concentration calcination conditions / Vasilije Manovic in Industrial & engineering chemistry research, Vol. 49 N° 15 (Août 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 15 (Août 2010) . - pp 6916–6922 Titre : CO2 carrying behavior of calcium aluminate pellets under high-temperature/high-CO2 concentration calcination conditions Type de document : texte imprimé Auteurs : Vasilije Manovic, Auteur ; Edward J. Anthony, Auteur Année de publication : 2010 Article en page(s) : pp 6916–6922 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Calcium  aluminate  High-CO2. Résumé : Sintering and a resulting loss of activity during calcination/carbonation can introduce substantial economic penalties for a CO2 looping cycle using CaO-based sorbents. In a real system, sorbent regeneration must be done at a high temperature to produce an almost pure CO2 stream, and this will increase both sintering and loss of sorbent activity. The influence of severe calcination conditions on the CO2 carrying behavior of calcium aluminate pellets is investigated here. Up to 30 calcination/carbonation cycles were performed using a thermogravimetric analyzer apparatus. The maximum temperature during the calcination stage in pure CO2 was 950 °C, using different heating/cooling rates between two carbonation stages (700 °C, 20% CO2). For comparison, cycles were also done using N2 during the calcination stages. In addition, the original Cadomin limestone, used for pelletization, was also examined in its original form and the results obtained were compared with those for the aluminate pellets. As expected, high temperature during calcination strongly reduced CO2 carrying capacities of both sorbents. However, aluminate pellets showed better resistance to these severe conditions. The conversion profiles obtained are significantly different to those obtained under milder conditions, with significant increased activity during the slower, diffusion-controlled, carbonation stage. Moreover, scanning electron microscopy analysis of samples after prolonged carbonation showed that pore filling occurred at the sorbent particle surfaces preventing diffusion of CO2 toward the particle interior. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901795e [article] CO2 carrying behavior of calcium aluminate pellets under high-temperature/high-CO2 concentration calcination conditions [texte imprimé] / Vasilije Manovic, Auteur ; Edward J. Anthony, Auteur . - 2010 . - pp 6916–6922. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 15 (Août 2010) . - pp 6916–6922 Mots-clés : Calcium  aluminate  High-CO2. Résumé : Sintering and a resulting loss of activity during calcination/carbonation can introduce substantial economic penalties for a CO2 looping cycle using CaO-based sorbents. In a real system, sorbent regeneration must be done at a high temperature to produce an almost pure CO2 stream, and this will increase both sintering and loss of sorbent activity. The influence of severe calcination conditions on the CO2 carrying behavior of calcium aluminate pellets is investigated here. Up to 30 calcination/carbonation cycles were performed using a thermogravimetric analyzer apparatus. The maximum temperature during the calcination stage in pure CO2 was 950 °C, using different heating/cooling rates between two carbonation stages (700 °C, 20% CO2). For comparison, cycles were also done using N2 during the calcination stages. In addition, the original Cadomin limestone, used for pelletization, was also examined in its original form and the results obtained were compared with those for the aluminate pellets. As expected, high temperature during calcination strongly reduced CO2 carrying capacities of both sorbents. However, aluminate pellets showed better resistance to these severe conditions. The conversion profiles obtained are significantly different to those obtained under milder conditions, with significant increased activity during the slower, diffusion-controlled, carbonation stage. Moreover, scanning electron microscopy analysis of samples after prolonged carbonation showed that pore filling occurred at the sorbent particle surfaces preventing diffusion of CO2 toward the particle interior. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901795e

Determining the accuracy of classical force fields for ionic liquids / Manish S. Kelkar in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9115–9126 Titre : Determining the accuracy of classical force fields for ionic liquids : atomistic simulation of the thermodynamic and transport properties of 1-Ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]) and its mixtures with water Type de document : texte imprimé Auteurs : Manish S. Kelkar, Auteur ; Wei Shi, Auteur ; Edward J. Anthony, Auteur Année de publication : 2009 Article en page(s) : p. 9115–9126 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Accuracy  of  classical  Ionic  liquids  Atomistic  simulation  of  the  thermodynamic Résumé : The ability of simple classical force fields to predict the structure and density of ionic liquids is now well-established. However, it is less clear how accurate such force fields are for a range of other pure and mixture properties of ionic liquids. In this work, a single classical force field is used to compute a wide range of thermodynamic and transport properties for the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]). In addition to liquid densities, the volumetric expansivity, heat capacity, enthalpy of vaporization, rotational relaxation time, self-diffusivity, shear viscosity, and thermal conductivity are computed at various temperatures for the pure ionic liquid. The density, excess molar volume, enthalpy of mixing, partial molar enthalpy, water solubility as a function of partial pressure, rotational relaxation time, self-diffusivity, shear viscosity, and thermal conductivity are also computed for mixtures that contain different concentrations of water at various temperatures. The agreement between simulations and experiment is fair for most properties, although deviations in enthalpy of mixing, viscosity, and self-diffusivity are often large. It is shown that much of the error for mixtures with water likely is due to neglect of the water polarizability, which results in too strong of an attraction between water and the [EtSO4] anion. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800843u#auth-fn1 [article] Determining the accuracy of classical force fields for ionic liquids : atomistic simulation of the thermodynamic and transport properties of 1-Ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]) and its mixtures with water [texte imprimé] / Manish S. Kelkar, Auteur ; Wei Shi, Auteur ; Edward J. Anthony, Auteur . - 2009 . - p. 9115–9126. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9115–9126 Mots-clés : Accuracy  of  classical  Ionic  liquids  Atomistic  simulation  of  the  thermodynamic Résumé : The ability of simple classical force fields to predict the structure and density of ionic liquids is now well-established. However, it is less clear how accurate such force fields are for a range of other pure and mixture properties of ionic liquids. In this work, a single classical force field is used to compute a wide range of thermodynamic and transport properties for the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]). In addition to liquid densities, the volumetric expansivity, heat capacity, enthalpy of vaporization, rotational relaxation time, self-diffusivity, shear viscosity, and thermal conductivity are computed at various temperatures for the pure ionic liquid. The density, excess molar volume, enthalpy of mixing, partial molar enthalpy, water solubility as a function of partial pressure, rotational relaxation time, self-diffusivity, shear viscosity, and thermal conductivity are also computed for mixtures that contain different concentrations of water at various temperatures. The agreement between simulations and experiment is fair for most properties, although deviations in enthalpy of mixing, viscosity, and self-diffusivity are often large. It is shown that much of the error for mixtures with water likely is due to neglect of the water polarizability, which results in too strong of an attraction between water and the [EtSO4] anion. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800843u#auth-fn1

Effect of partial carbonation on the cyclic CaO carbonation reaction / Gemma Grasa in Industrial & engineering chemistry research, Vol. 48 N° 20 (Octobre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 20 (Octobre 2009) . - pp. Titre : Effect of partial carbonation on the cyclic CaO carbonation reaction Type de document : texte imprimé Auteurs : Gemma Grasa, Auteur ; Juan Carlos Abanades, Auteur ; Edward J. Anthony, Auteur Année de publication : 2010 Article en page(s) : pp. Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : CaO  particles  Carbonation Résumé : CaO particles from the calcination of natural limestones can be used as regenerable solid sorbents in some CO2 capture systems. Their decay curves in terms of CO2 capture capacity have been extensively studied in the literature, always in experiments allowing particles to reach their maximum carbonation conversion for a given cycle. However, at the expected operating conditions in a CO2 capture system using the carbonation reaction, a relevant fraction of the CaO particles will not have time to fully convert in the carbonator reactor. This work investigates if there is any effect on the decay curves when CaO is only partially converted in each cycle. Experiments have been conducted in a thermobalance arranged to interrupt the carbonation reaction in each cycle before the end of the fast reaction period typical in the CaO−CO2 reaction. It is shown that, after the necessary normalization of results, the effective capacity of the sorbent to absorb CO2 during particle lifetime in the capture system slightly increases and CaO particles partially converted behave “younger” than particles fully converted after every calcination. This has beneficial implications for the design of carbonation/calcination loops. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900443y [article] Effect of partial carbonation on the cyclic CaO carbonation reaction [texte imprimé] / Gemma Grasa, Auteur ; Juan Carlos Abanades, Auteur ; Edward J. Anthony, Auteur . - 2010 . - pp. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 20 (Octobre 2009) . - pp. Mots-clés : CaO  particles  Carbonation Résumé : CaO particles from the calcination of natural limestones can be used as regenerable solid sorbents in some CO2 capture systems. Their decay curves in terms of CO2 capture capacity have been extensively studied in the literature, always in experiments allowing particles to reach their maximum carbonation conversion for a given cycle. However, at the expected operating conditions in a CO2 capture system using the carbonation reaction, a relevant fraction of the CaO particles will not have time to fully convert in the carbonator reactor. This work investigates if there is any effect on the decay curves when CaO is only partially converted in each cycle. Experiments have been conducted in a thermobalance arranged to interrupt the carbonation reaction in each cycle before the end of the fast reaction period typical in the CaO−CO2 reaction. It is shown that, after the necessary normalization of results, the effective capacity of the sorbent to absorb CO2 during particle lifetime in the capture system slightly increases and CaO particles partially converted behave “younger” than particles fully converted after every calcination. This has beneficial implications for the design of carbonation/calcination loops. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900443y

Long-term behavior of CaO-based pellets supported by calcium aluminate cements in a long series of CO2 capture cycles / Vasilije Manovic in Industrial & engineering chemistry research, Vol. 48 N° 19 (Octobre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 19 (Octobre 2009) . - pp. 8906–8912 Titre : Long-term behavior of CaO-based pellets supported by calcium aluminate cements in a long series of CO2 capture cycles Type de document : texte imprimé Auteurs : Vasilije Manovic, Auteur ; Edward J. Anthony, Auteur Année de publication : 2009 Article en page(s) : pp. 8906–8912 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : CaO-based  pellets  CO2  carrying  capacity  Thermogravimetric  analyzer  Scanning  electron  microscopy Résumé : A series of carbonation/calcination tests consisting of 1000 cycles was performed with CaO-based pellets prepared using hydrated lime and calcium aluminate cement. The change in CO2 carrying capacity of the sorbent was investigated in a thermogravimetric analyzer (TGA) apparatus and the morphology of residues after those cycles in the TGA was examined by scanning electron microscopy (SEM). Larger quantities of sorbent pellets underwent 300 carbonation/calcination cycles in a tube furnace (TF), and their properties were examined by nitrogen physisorption tests (BET and BJH). The crushing strength of the pellets before and after the CO2 cycles was determined by means of a custom-made strength testing apparatus. The results showed high CO2 carrying capacity in long series of cycles with an extremely high residual activity of the order of 28%. This superior performance is a result of favorable morphology due to the existence of large numbers of nanosized pores suitable for carbonation. This morphology is relatively stable during cycles due to the presence of mayenite (Ca12Al14O33) in the CaO structure. However, the crushing tests showed that pellets lost strength after 300 carbonation/calcination cycles, and this appears to be due to the cracks formed in the pellets. This effect was not observed in smaller particles suitable for use in fluidized bed (FBC) systems. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9011529 [article] Long-term behavior of CaO-based pellets supported by calcium aluminate cements in a long series of CO2 capture cycles [texte imprimé] / Vasilije Manovic, Auteur ; Edward J. Anthony, Auteur . - 2009 . - pp. 8906–8912. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 19 (Octobre 2009) . - pp. 8906–8912 Mots-clés : CaO-based  pellets  CO2  carrying  capacity  Thermogravimetric  analyzer  Scanning  electron  microscopy Résumé : A series of carbonation/calcination tests consisting of 1000 cycles was performed with CaO-based pellets prepared using hydrated lime and calcium aluminate cement. The change in CO2 carrying capacity of the sorbent was investigated in a thermogravimetric analyzer (TGA) apparatus and the morphology of residues after those cycles in the TGA was examined by scanning electron microscopy (SEM). Larger quantities of sorbent pellets underwent 300 carbonation/calcination cycles in a tube furnace (TF), and their properties were examined by nitrogen physisorption tests (BET and BJH). The crushing strength of the pellets before and after the CO2 cycles was determined by means of a custom-made strength testing apparatus. The results showed high CO2 carrying capacity in long series of cycles with an extremely high residual activity of the order of 28%. This superior performance is a result of favorable morphology due to the existence of large numbers of nanosized pores suitable for carbonation. This morphology is relatively stable during cycles due to the presence of mayenite (Ca12Al14O33) in the CaO structure. However, the crushing tests showed that pellets lost strength after 300 carbonation/calcination cycles, and this appears to be due to the cracks formed in the pellets. This effect was not observed in smaller particles suitable for use in fluidized bed (FBC) systems. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9011529

SO2 retention by CaO-based sorbent spent in CO2 looping cycles / Vasilije Manovic in Industrial & engineering chemistry research, Vol. 48 N° 14 (Juillet 2009) 

Permalink