Calculation of entropy production in process models

Pertti Koukkari, S. Liukkonen

Research output: Contribution to journalArticleScientificpeer-review

6 Citations (Scopus)

Abstract

A thermochemical method is presented by which multiphase processes can be simulated with concurrent calculation of the Gibbs energy of the reactive mixture during a chemical change. Algorithmic constraints are set for the overall reaction kinetics when the Lagrange method of undetermined multipliers is used to minimize the Gibbs energy of the multicomponent system.
Consequently, the chemical change is calculated as a series of successive “virtual” states, which follow the extent of the overall reaction. From the Gibbs energy of these intermediate states, other thermodynamic quantities for the changing chemical system can be deduced, and the entropy production of the process can be calculated.
A particular process model was developed for two isothermal aqueous systems and for a nonisothermal high-temperature process.
The entropy production in the reactive systems is presented, and the validity of the simulation models is assessed in terms of their time-dependent Gibbs energy and entropy profiles.
Original languageEnglish
Pages (from-to)2931-2940
JournalIndustrial & Engineering Chemistry Research
Volume41
Issue number12
DOIs
Publication statusPublished - 2002
MoE publication typeA1 Journal article-refereed

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Gibbs free energy
Entropy
Reaction kinetics
Thermodynamics
Temperature

Keywords

  • thermochemical processes
  • Gibbs energy minimization
  • entropy
  • simulation
  • modelling

Cite this

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author = "Pertti Koukkari and S. Liukkonen",
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Calculation of entropy production in process models. / Koukkari, Pertti; Liukkonen, S.

In: Industrial & Engineering Chemistry Research, Vol. 41, No. 12, 2002, p. 2931-2940.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Calculation of entropy production in process models

AU - Koukkari, Pertti

AU - Liukkonen, S.

PY - 2002

Y1 - 2002

N2 - A thermochemical method is presented by which multiphase processes can be simulated with concurrent calculation of the Gibbs energy of the reactive mixture during a chemical change. Algorithmic constraints are set for the overall reaction kinetics when the Lagrange method of undetermined multipliers is used to minimize the Gibbs energy of the multicomponent system. Consequently, the chemical change is calculated as a series of successive “virtual” states, which follow the extent of the overall reaction. From the Gibbs energy of these intermediate states, other thermodynamic quantities for the changing chemical system can be deduced, and the entropy production of the process can be calculated. A particular process model was developed for two isothermal aqueous systems and for a nonisothermal high-temperature process. The entropy production in the reactive systems is presented, and the validity of the simulation models is assessed in terms of their time-dependent Gibbs energy and entropy profiles.

AB - A thermochemical method is presented by which multiphase processes can be simulated with concurrent calculation of the Gibbs energy of the reactive mixture during a chemical change. Algorithmic constraints are set for the overall reaction kinetics when the Lagrange method of undetermined multipliers is used to minimize the Gibbs energy of the multicomponent system. Consequently, the chemical change is calculated as a series of successive “virtual” states, which follow the extent of the overall reaction. From the Gibbs energy of these intermediate states, other thermodynamic quantities for the changing chemical system can be deduced, and the entropy production of the process can be calculated. A particular process model was developed for two isothermal aqueous systems and for a nonisothermal high-temperature process. The entropy production in the reactive systems is presented, and the validity of the simulation models is assessed in terms of their time-dependent Gibbs energy and entropy profiles.

KW - thermochemical processes

KW - Gibbs energy minimization

KW - entropy

KW - simulation

KW - modelling

U2 - 10.1021/ie010498t

DO - 10.1021/ie010498t

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VL - 41

SP - 2931

EP - 2940

JO - Industrial & Engineering Chemistry Research

JF - Industrial & Engineering Chemistry Research

SN - 0888-5885

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