### Abstract

The dynamics of flash drums is simulated using a formulation adequate for phase modeling with equations of state (EOS). The energy and mass balances are written as differential equations for the internal energy and the number of moles of each species. The algebraic equations of the model, solved at each time step, are those of a flash with specified internal energy, volume and mole numbers (UVN flash). A new aspect of our dynamic simulations is the use of direct iterations in phase volumes (instead of pressure) for solving the algebraic equations. It was also found that an iterative procedure previously suggested in the literature for UVN flashes becomes unreliable close to phase boundaries and a new alternative is proposed. Another unusual aspect of this work is that the model expressions, including the physical properties and their analytical derivatives, were quickly implemented using computer algebra.

Original language | English |
---|---|

Pages (from-to) | 277-286 |

Number of pages | 10 |

Journal | Brazilian Journal of Chemical Engineering |

Volume | 24 |

Issue number | 2 |

Publication status | Published - Apr 2007 |

Externally published | Yes |

### Fingerprint

### Keywords

- Differential-algebraic equations
- Dynamic simulation
- Equation of state
- Flash
- Hydrocarbons
- Phase equilibrium

### ASJC Scopus subject areas

- Chemical Engineering(all)

### Cite this

*Brazilian Journal of Chemical Engineering*,

*24*(2), 277-286.

**Dynamic simulation of flash drums using rigorous physical property calculations.** / Gonçalves, F. M.; Castier, M.; Araújo, O. Q F.

Research output: Contribution to journal › Article

*Brazilian Journal of Chemical Engineering*, vol. 24, no. 2, pp. 277-286.

}

TY - JOUR

T1 - Dynamic simulation of flash drums using rigorous physical property calculations

AU - Gonçalves, F. M.

AU - Castier, M.

AU - Araújo, O. Q F

PY - 2007/4

Y1 - 2007/4

N2 - The dynamics of flash drums is simulated using a formulation adequate for phase modeling with equations of state (EOS). The energy and mass balances are written as differential equations for the internal energy and the number of moles of each species. The algebraic equations of the model, solved at each time step, are those of a flash with specified internal energy, volume and mole numbers (UVN flash). A new aspect of our dynamic simulations is the use of direct iterations in phase volumes (instead of pressure) for solving the algebraic equations. It was also found that an iterative procedure previously suggested in the literature for UVN flashes becomes unreliable close to phase boundaries and a new alternative is proposed. Another unusual aspect of this work is that the model expressions, including the physical properties and their analytical derivatives, were quickly implemented using computer algebra.

AB - The dynamics of flash drums is simulated using a formulation adequate for phase modeling with equations of state (EOS). The energy and mass balances are written as differential equations for the internal energy and the number of moles of each species. The algebraic equations of the model, solved at each time step, are those of a flash with specified internal energy, volume and mole numbers (UVN flash). A new aspect of our dynamic simulations is the use of direct iterations in phase volumes (instead of pressure) for solving the algebraic equations. It was also found that an iterative procedure previously suggested in the literature for UVN flashes becomes unreliable close to phase boundaries and a new alternative is proposed. Another unusual aspect of this work is that the model expressions, including the physical properties and their analytical derivatives, were quickly implemented using computer algebra.

KW - Differential-algebraic equations

KW - Dynamic simulation

KW - Equation of state

KW - Flash

KW - Hydrocarbons

KW - Phase equilibrium

UR - http://www.scopus.com/inward/record.url?scp=34547511415&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34547511415&partnerID=8YFLogxK

M3 - Article

VL - 24

SP - 277

EP - 286

JO - Brazilian Journal of Chemical Engineering

JF - Brazilian Journal of Chemical Engineering

SN - 0104-6632

IS - 2

ER -