Documents disponibles écrits par cet auteur

Adapting process unit relations in experimental data weighting procedures / Ngigi, Geoffrey K. in Industrial & engineering chemistry research, Vol. 49 N° 4 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1975–1981 Titre : Adapting process unit relations in experimental data weighting procedures : a phase equilibrium case study Type de document : texte imprimé Auteurs : Ngigi, Geoffrey K., Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur Année de publication : 2010 Article en page(s) : pp 1975–1981 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Weighting  method  Phase  equilibrium. Résumé : A data weighting method derived from analysis of the distillation column design relation(s) is used on several experimental vapor−liquid equilibrium (VLE) sets of data for estimating the interaction pair parameters of two local-composition models (NRTL and Wilson). It is shown that process equations can provide insights on the requisite objective function(s) to obtain parameters more suited to a particular design intent. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801987j [article] Adapting process unit relations in experimental data weighting procedures : a phase equilibrium case study [texte imprimé] / Ngigi, Geoffrey K., Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur . - 2010 . - pp 1975–1981. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1975–1981 Mots-clés : Weighting  method  Phase  equilibrium. Résumé : A data weighting method derived from analysis of the distillation column design relation(s) is used on several experimental vapor−liquid equilibrium (VLE) sets of data for estimating the interaction pair parameters of two local-composition models (NRTL and Wilson). It is shown that process equations can provide insights on the requisite objective function(s) to obtain parameters more suited to a particular design intent. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801987j

Candidate attainable regions for the oxidative dehydrogenation of n-butane using the recursive constant control (RCC) policy algorithm / David Milne in Industrial & engineering chemistry research, Vol. 48 N° 11 (Juin 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 11 (Juin 2009) . - pp. 5211–5222 Titre : Candidate attainable regions for the oxidative dehydrogenation of n-butane using the recursive constant control (RCC) policy algorithm Type de document : texte imprimé Auteurs : David Milne, Auteur ; Tumisang Seodigeng, Auteur ; David Glasser, Auteur Année de publication : 2009 Article en page(s) : pp. 5211–5222 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Attainable  region  Oxidative  dehydrogenation  N-butane Résumé : Attainable region (AR) ideas have previously been used to identify candidate attainable regions (ARCs) for the oxidative dehydrogenation (ODH) of n-butane to butenes and butadiene and in so doing to identify the maximum possible yields of different hydrocarbon product. Because of the large dimensionality of the problem, it was not possible then to do a complete AR analysis. Among the configurations considered, it was found that the reactor configuration for the respective ARCs in all instances was an inert membrane reactor (IMR) functioning as a differential side-stream reactor in which one of the reactants, oxygen, was introduced along the length of the reactor so as to maintain a very low and constant value of its partial pressure. Nevertheless, despite producing high yields of product, extremely large and impractical residence times ensued. In this paper, a new tool, the recursive convex control (RCC) policy, is used to identify the ARCs in the full dimensional space. These ARCs showed excellent agreement with those previously published, and the optimal reactor structures presented in those publications have been confirmed albeit with different oxygen control parameters. The maximum yields are now achieved with very much lower residence times. These results also confirm the benefit from using the AR approach on problems where a full AR analysis is not possible. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801600w [article] Candidate attainable regions for the oxidative dehydrogenation of n-butane using the recursive constant control (RCC) policy algorithm [texte imprimé] / David Milne, Auteur ; Tumisang Seodigeng, Auteur ; David Glasser, Auteur . - 2009 . - pp. 5211–5222. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 11 (Juin 2009) . - pp. 5211–5222 Mots-clés : Attainable  region  Oxidative  dehydrogenation  N-butane Résumé : Attainable region (AR) ideas have previously been used to identify candidate attainable regions (ARCs) for the oxidative dehydrogenation (ODH) of n-butane to butenes and butadiene and in so doing to identify the maximum possible yields of different hydrocarbon product. Because of the large dimensionality of the problem, it was not possible then to do a complete AR analysis. Among the configurations considered, it was found that the reactor configuration for the respective ARCs in all instances was an inert membrane reactor (IMR) functioning as a differential side-stream reactor in which one of the reactants, oxygen, was introduced along the length of the reactor so as to maintain a very low and constant value of its partial pressure. Nevertheless, despite producing high yields of product, extremely large and impractical residence times ensued. In this paper, a new tool, the recursive convex control (RCC) policy, is used to identify the ARCs in the full dimensional space. These ARCs showed excellent agreement with those previously published, and the optimal reactor structures presented in those publications have been confirmed albeit with different oxygen control parameters. The maximum yields are now achieved with very much lower residence times. These results also confirm the benefit from using the AR approach on problems where a full AR analysis is not possible. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801600w

Fischer − tropsch synthesis using H2 / CO / CO2 syngas mixtures over a cobalt catalyst / Yali Yao in Industrial & engineering chemistry research, Vol. 49 N° 21 (Novembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 11061-11066 Titre : Fischer − tropsch synthesis using H2 / CO / CO2 syngas mixtures over a cobalt catalyst Type de document : texte imprimé Auteurs : Yali Yao, Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur Année de publication : 2011 Article en page(s) : pp. 11061-11066 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst  Synthesis  gas  Carbon  dioxide  Fischer  Tropsch  synthesis Résumé : The effect of CO2 on Fischer−Tropsch synthesis (FTS) on a cobalt based catalyst had been investigated in a fixed-bed microreactor. Two feed gases, H2:CO:CO2 = 2:1:0 and H2:CO:CO2 = 3:0:1, were mixed in various proportions thus varying the ratio of CO, CO2, and H2 stoichiometrically. The results show that CO and CO2 mixtures can be used as feed to a cobalt catalyst. Comparison of the FTS using different syngas mixtures (CO2/H2, CO2/CO/H2, and CO/H2) shows that: (1) CO2 can be hydrogenated along with CO in the FT reactor over cobalt catalyst, especially in the case of high content of CO2. (2) Hydrogenation of CO2 or CO/CO2 mixture leads to a typical Anderson−Schulz−Flory (ASF) distribution. These could support the hypothesis that CO2 hydrogenation processes might occur with the formation of CO as intermediate. (3) CO feed exhibit the typical two-alpha distribution while CO2 and CO2 rich feeds only exhibit a single-alpha distribution. This may also help us to understand the mechanisms that lead to product distributions in FT with single- and dual-alpha distributions. In spite of the fact that cobalt catalysts are not water−gas shift active, it is shown the rate of hydrocarbon production is maximized at an intermediate composition of the CO/CO2/H2 mixture. The results could have implications for the design of XTL (anything-to-liquids is a process that converts carbon and energy containing feedstock to high quality fuels and products, such as coal-to-liquids, biomass-to-liquids and gas-to-liquids) using cobalt catalysts in that it might be advantageous to keep some carbon dioxide in the syngas feed to the FTS process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23448002 [article] Fischer − tropsch synthesis using H2 / CO / CO2 syngas mixtures over a cobalt catalyst [texte imprimé] / Yali Yao, Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur . - 2011 . - pp. 11061-11066. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 11061-11066 Mots-clés : Catalyst  Synthesis  gas  Carbon  dioxide  Fischer  Tropsch  synthesis Résumé : The effect of CO2 on Fischer−Tropsch synthesis (FTS) on a cobalt based catalyst had been investigated in a fixed-bed microreactor. Two feed gases, H2:CO:CO2 = 2:1:0 and H2:CO:CO2 = 3:0:1, were mixed in various proportions thus varying the ratio of CO, CO2, and H2 stoichiometrically. The results show that CO and CO2 mixtures can be used as feed to a cobalt catalyst. Comparison of the FTS using different syngas mixtures (CO2/H2, CO2/CO/H2, and CO/H2) shows that: (1) CO2 can be hydrogenated along with CO in the FT reactor over cobalt catalyst, especially in the case of high content of CO2. (2) Hydrogenation of CO2 or CO/CO2 mixture leads to a typical Anderson−Schulz−Flory (ASF) distribution. These could support the hypothesis that CO2 hydrogenation processes might occur with the formation of CO as intermediate. (3) CO feed exhibit the typical two-alpha distribution while CO2 and CO2 rich feeds only exhibit a single-alpha distribution. This may also help us to understand the mechanisms that lead to product distributions in FT with single- and dual-alpha distributions. In spite of the fact that cobalt catalysts are not water−gas shift active, it is shown the rate of hydrocarbon production is maximized at an intermediate composition of the CO/CO2/H2 mixture. The results could have implications for the design of XTL (anything-to-liquids is a process that converts carbon and energy containing feedstock to high quality fuels and products, such as coal-to-liquids, biomass-to-liquids and gas-to-liquids) using cobalt catalysts in that it might be advantageous to keep some carbon dioxide in the syngas feed to the FTS process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23448002

A Graphical method of improving the production rate from batch reactors / David Ming in Industrial & engineering chemistry research, Vol. 51 N° 42 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13562-13573 Titre : A Graphical method of improving the production rate from batch reactors Type de document : texte imprimé Auteurs : David Ming, Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur Année de publication : 2012 Article en page(s) : pp. 13562-13573 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reactor  Batchwise  Production Résumé : In this work, a graphical method of identifying opportunities for improving the production rate from batch reactors is presented. On the basis of this approach, a modification to the standard procedure of batch operation is also developed. It is found that by modifying the initial concentration of the batch, overall production performance may be improved. This may be achieved in practice by retaining a fraction of the final product volume and mixing with fresh feed material for the next batch cycle. This result is counterintuitive to the normal method of batch operation. Arguments demonstrating how the graphical method may be used to gain insight into alternative methods of operation are also briefly discussed. As such, the bypassing of feed may also be used to improve production rate for exit concentrations not associated with the optimal concentration. The graphical approach also allows optimization of batches where only experimental data are given. The method is demonstrated through several industrial examples and is successfully shown to improve over the standard method of batch operation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26508179 [article] A Graphical method of improving the production rate from batch reactors [texte imprimé] / David Ming, Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur . - 2012 . - pp. 13562-13573. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13562-13573 Mots-clés : Reactor  Batchwise  Production Résumé : In this work, a graphical method of identifying opportunities for improving the production rate from batch reactors is presented. On the basis of this approach, a modification to the standard procedure of batch operation is also developed. It is found that by modifying the initial concentration of the batch, overall production performance may be improved. This may be achieved in practice by retaining a fraction of the final product volume and mixing with fresh feed material for the next batch cycle. This result is counterintuitive to the normal method of batch operation. Arguments demonstrating how the graphical method may be used to gain insight into alternative methods of operation are also briefly discussed. As such, the bypassing of feed may also be used to improve production rate for exit concentrations not associated with the optimal concentration. The graphical approach also allows optimization of batches where only experimental data are given. The method is demonstrated through several industrial examples and is successfully shown to improve over the standard method of batch operation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26508179

On column profile maps / Daniel A. Beneke in Industrial & engineering chemistry research, Vol. 50 N° 10 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6331-6342 Titre : On column profile maps : an analysis of sharp splits Type de document : texte imprimé Auteurs : Daniel A. Beneke, Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur Année de publication : 2011 Article en page(s) : pp. 6331-6342 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Cartography Résumé : Column profile maps (CPMs) have recently been shown to be a useful tool in the design of distillation operations, especially complex configurations. CPMs are essentially a family of composition trajectories for a column section in a distillation column. They have been shown to be topological transforms of residue curve maps, and are dependent on two main parameters: RΔ (generalized reflux) and XΔ (a pseudocomposition vector), which effectively fixes the net flow in a column section. This paper focuses on the interaction between these parameters for the special case of sharp splits. With the CPM technique it has been shown that sharp splits behave in a unique manner, due to a phenomenon termed as "node bumping". In particular, it has been shown that it is possible to locate specific ranges of RΔ where one may drastically influence the movement of profiles in somewhat counterintuitive directions. Although this effect may not be useful in product producing column sections, it is shown how these unique phenomena can affect a separation in a desirable manner, especially when designing unconventional column configurations. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158928 [article] On column profile maps : an analysis of sharp splits [texte imprimé] / Daniel A. Beneke, Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur . - 2011 . - pp. 6331-6342. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6331-6342 Mots-clés : Cartography Résumé : Column profile maps (CPMs) have recently been shown to be a useful tool in the design of distillation operations, especially complex configurations. CPMs are essentially a family of composition trajectories for a column section in a distillation column. They have been shown to be topological transforms of residue curve maps, and are dependent on two main parameters: RΔ (generalized reflux) and XΔ (a pseudocomposition vector), which effectively fixes the net flow in a column section. This paper focuses on the interaction between these parameters for the special case of sharp splits. With the CPM technique it has been shown that sharp splits behave in a unique manner, due to a phenomenon termed as "node bumping". In particular, it has been shown that it is possible to locate specific ranges of RΔ where one may drastically influence the movement of profiles in somewhat counterintuitive directions. Although this effect may not be useful in product producing column sections, it is shown how these unique phenomena can affect a separation in a desirable manner, especially when designing unconventional column configurations. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158928

A Revised method of attainable region construction utilizing rotated bounding hyperplanes / David Ming in Industrial & engineering chemistry research, Vol. 49 N° 21 (Novembre 2010) 

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