Documents disponibles écrits par cet auteur

A Natural Gas to Liquids Process Model for Optimal Operation / Mehdi Panahi in Industrial & engineering chemistry research, Vol. 51 N° 1 (Janvier 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 1 (Janvier 2012) . - pp. 425-433 Titre : A Natural Gas to Liquids Process Model for Optimal Operation Type de document : texte imprimé Auteurs : Mehdi Panahi, Auteur ; Ahmad Rafiee, Auteur ; Sigurd Skogestad, Auteur Année de publication : 2012 Article en page(s) : pp. 425-433 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling  Natural  gas Résumé : The design and optimization of a natural gas to hydrocarbon liquids (GTL) process is considered, mainly from the view of maximizing the variable income during operation. Autothermal reforming (ATR) is used for synthesis gas production. The kinetic model for Fischer-Tropsch (FT) reactions is the one given by Iglesia et al. for a cobalt-based FT reactor. For the product distribution, three alternative expressions for the chain growth factor α are compared. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25476486 [article] A Natural Gas to Liquids Process Model for Optimal Operation [texte imprimé] / Mehdi Panahi, Auteur ; Ahmad Rafiee, Auteur ; Sigurd Skogestad, Auteur . - 2012 . - pp. 425-433. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 1 (Janvier 2012) . - pp. 425-433 Mots-clés : Modeling  Natural  gas Résumé : The design and optimization of a natural gas to hydrocarbon liquids (GTL) process is considered, mainly from the view of maximizing the variable income during operation. Autothermal reforming (ATR) is used for synthesis gas production. The kinetic model for Fischer-Tropsch (FT) reactions is the one given by Iglesia et al. for a cobalt-based FT reactor. For the product distribution, three alternative expressions for the chain growth factor α are compared. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25476486

Selection of controlled variables for a natural gas to liquids process / Mehdi Panahi in Industrial & engineering chemistry research, Vol. 51 N° 30 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 30 (Août 2012) . - pp. 10179-10190 Titre : Selection of controlled variables for a natural gas to liquids process Type de document : texte imprimé Auteurs : Mehdi Panahi, Auteur ; Sigurd Skogestad, Auteur Année de publication : 2012 Article en page(s) : pp. 10179-10190 Note générale : Industrial chmistry Langues : Anglais (eng) Mots-clés : Natural  gas Résumé : The aim of this work is to select the best individual or combined controlled variables (CVs) for a natural gas to hydrocarbon liquids (GTL) process based on the idea of self-optimizing control. The objective function is to maximize the variable income of the plant, and two modes of operation are studied. In mode I, where the natural gas flow rate is given, there are three unconstrained degrees of freedom (DOFs) and the corresponding individual self-optimizing CVs are selected as (i) CO2 removal in fresh synthesis gas (syngas), (ii) CO mole fraction in fresh syngas, and (iii) CO mole fraction in recycle tail gas from the Fischer—Tropsch (FT) reactor. This set of CVs gives a worst-case loss of 1,393 USD/h. Adding one, two, and three measurements and controlling measurement combinations decrease the worst-case loss significantly, to 184, 161, and 53 USD/h, respectively. In mode II, the natural gas flow rate is a degree of freedom and it is optimal to increase it as much as possible to maximize profit. The variable income increases almost linearly until the oxygen flow rate becomes active. Practically, this is the maximum achievable income. Theoretically, it is possible to increase the natural gas flow rate to improve the objective function, but this results in large recycle flow rates to the FT reactor (similar to "snowballing") because its volume is the limitation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26201434 [article] Selection of controlled variables for a natural gas to liquids process [texte imprimé] / Mehdi Panahi, Auteur ; Sigurd Skogestad, Auteur . - 2012 . - pp. 10179-10190. Industrial chmistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 30 (Août 2012) . - pp. 10179-10190 Mots-clés : Natural  gas Résumé : The aim of this work is to select the best individual or combined controlled variables (CVs) for a natural gas to hydrocarbon liquids (GTL) process based on the idea of self-optimizing control. The objective function is to maximize the variable income of the plant, and two modes of operation are studied. In mode I, where the natural gas flow rate is given, there are three unconstrained degrees of freedom (DOFs) and the corresponding individual self-optimizing CVs are selected as (i) CO2 removal in fresh synthesis gas (syngas), (ii) CO mole fraction in fresh syngas, and (iii) CO mole fraction in recycle tail gas from the Fischer—Tropsch (FT) reactor. This set of CVs gives a worst-case loss of 1,393 USD/h. Adding one, two, and three measurements and controlling measurement combinations decrease the worst-case loss significantly, to 184, 161, and 53 USD/h, respectively. In mode II, the natural gas flow rate is a degree of freedom and it is optimal to increase it as much as possible to maximize profit. The variable income increases almost linearly until the oxygen flow rate becomes active. Practically, this is the maximum achievable income. Theoretically, it is possible to increase the natural gas flow rate to improve the objective function, but this results in large recycle flow rates to the FT reactor (similar to "snowballing") because its volume is the limitation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26201434