Abstract
We describe a generalization of the negative-flash method for computing the equilibrium compositions of systems that can form more than two fluid phases. We show the solution existence and uniqueness of the general Rachford-Rice problem for systems with any number of phases. A bisection based strategy is proposed either as a solution procedure to guarantee convergence, or as a preconditioning step of Newton based methods. A multi-stage negative-flash procedure is developed to identify the state of a multicomponent mixture where the maximum number of phases is arbitrary. The approach should be used in combination with a tie-simplex based modeling framework to provide a general method for phase behavior computations. Challenging numerical examples are presented to demonstrate the accuracy and robustness of the negative-flash approach.
Original language | English |
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Pages (from-to) | 272-284 |
Number of pages | 13 |
Journal | Fluid Phase Equilibria |
Volume | 299 |
Issue number | 2 |
DOIs | |
Publication status | Published - 25 Dec 2010 |
Externally published | Yes |
Keywords
- Arbitrary number of phases
- Compositional space parameterization
- Negative flash
- Thermodynamic phase-state identification
- Tie-simplex