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Analytical solution for discrete lumped kinetic equations in hydrocracking of heavier petroleum fractions / P. C. Krishna in Industrial & engineering chemistry research, Vol. 48 N° 14 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 14 (Juillet 2009) . - pp. 6608–6617 Titre : Analytical solution for discrete lumped kinetic equations in hydrocracking of heavier petroleum fractions Type de document : texte imprimé Auteurs : P. C. Krishna, Auteur ; P. Balasubramanian, Auteur Année de publication : 2009 Article en page(s) : pp. 6608–6617 Note générale : chemical engineering Langues : Anglais (eng) Mots-clés : Stoichiometry  Discrete  lumped  kinetic  mode  Carbon  number  basis Résumé : This paper provides a general analytical solution for the full stoichiometry based discrete lumped kinetic model. The reduced stoichiometry and carbon number basis are the subset of the full stoichiometry model. The exponential form of stoichiometric kernels is considered to study the product distribution for the full and reduced stoichiometry models. Here, full stoichiometry favors for the formation of heavier lumps, while the reduced stoichiometry favors for the formation of lighter lumps. The exact solution for the discrete lumped model is validated with the experimental data cited in the literature. The model validation reveals that the full stoichiometry is the best performing model for hydrocracking of heavier petroleum fractions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900178m [article] Analytical solution for discrete lumped kinetic equations in hydrocracking of heavier petroleum fractions [texte imprimé] / P. C. Krishna, Auteur ; P. Balasubramanian, Auteur . - 2009 . - pp. 6608–6617. chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 14 (Juillet 2009) . - pp. 6608–6617 Mots-clés : Stoichiometry  Discrete  lumped  kinetic  mode  Carbon  number  basis Résumé : This paper provides a general analytical solution for the full stoichiometry based discrete lumped kinetic model. The reduced stoichiometry and carbon number basis are the subset of the full stoichiometry model. The exponential form of stoichiometric kernels is considered to study the product distribution for the full and reduced stoichiometry models. Here, full stoichiometry favors for the formation of heavier lumps, while the reduced stoichiometry favors for the formation of lighter lumps. The exact solution for the discrete lumped model is validated with the experimental data cited in the literature. The model validation reveals that the full stoichiometry is the best performing model for hydrocracking of heavier petroleum fractions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900178m

Numerical bifurcation analysis of delay in a coupled reactor separator system / P. Balasubramanian in Industrial & engineering chemistry research, Vol. 47 n°11 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3920–3929 Titre : Numerical bifurcation analysis of delay in a coupled reactor separator system Type de document : texte imprimé Auteurs : P. Balasubramanian, Auteur Année de publication : 2008 Article en page(s) : p. 3920–3929 Note générale : Bibliogr. p. 3928-3929 Langues : Anglais (eng) Mots-clés : Coupled  reactor  separator  system;  DDE-BIFTOOL  software  package;  Delay  arising Résumé : The effect of delay on the stability of a coupled reactor separator system is investigated in this work, using the DDE-BIFTOOL software package. The reactor considered is a continuously stirred tank reactor (CSTR), and the separator is modeled as a flash unit operating isothermally and isobarically. A first-order isothermal irreversible reaction A → B is considered to investigate the effect of delay arising as a result of transportation lag from the CSTR to the flash. The dynamic behavior of the coupled CSTR−flash system is governed by the delay differential equations. In this work, the dynamic instability induced by delay that is crucially dependent on the flow control strategy of the system is investigated using DDE-BIFTOOL. It is shown that delay can destabilize the steady state of the coupled system when the reactor effluent flow rate F is flow-controlled, and the molar holdup MR in the reactor is allowed to vary. When the fresh feed flow rate F0 is flow-controlled, the system exhibits delay-independent stability. The critical delay and frequency of oscillation obtained using DDE-BIFTOOL show good agreement with the same obtained using the analytical expressions proposed in the literature. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071010c [article] Numerical bifurcation analysis of delay in a coupled reactor separator system [texte imprimé] / P. Balasubramanian, Auteur . - 2008 . - p. 3920–3929. Bibliogr. p. 3928-3929 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3920–3929 Mots-clés : Coupled  reactor  separator  system;  DDE-BIFTOOL  software  package;  Delay  arising Résumé : The effect of delay on the stability of a coupled reactor separator system is investigated in this work, using the DDE-BIFTOOL software package. The reactor considered is a continuously stirred tank reactor (CSTR), and the separator is modeled as a flash unit operating isothermally and isobarically. A first-order isothermal irreversible reaction A → B is considered to investigate the effect of delay arising as a result of transportation lag from the CSTR to the flash. The dynamic behavior of the coupled CSTR−flash system is governed by the delay differential equations. In this work, the dynamic instability induced by delay that is crucially dependent on the flow control strategy of the system is investigated using DDE-BIFTOOL. It is shown that delay can destabilize the steady state of the coupled system when the reactor effluent flow rate F is flow-controlled, and the molar holdup MR in the reactor is allowed to vary. When the fresh feed flow rate F0 is flow-controlled, the system exhibits delay-independent stability. The critical delay and frequency of oscillation obtained using DDE-BIFTOOL show good agreement with the same obtained using the analytical expressions proposed in the literature. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071010c