High-pressure vapor-liquid equilibrium with a UNIFAC-based equation of state
TL;DR: In this paper, the ability of the mixing rules proposed by Michelsen to predict high-pressure phase equilibrium, when used in combination with the parameter table of modified UNIFAC, was investigated.
Abstract: Recent procedures developed by Heidemann (1990) and by Michelsen (1990a, b) enable us to formally incorporate excess Gibbs energy model parameters into a fully consistent equation of state, cith accurate reproduction of the behavior of the excess Gibbs energy model at atmospheric pressure.
This paper investigates the ability of the mixing rules proposed by Michelsen to predict high-pressure phase equilibrium, when used in combination with the parameter table of modified UNIFAC. Considering that a group contribution method is used for the excess Gibbs energy and that model parameters are extrapolated over a 200 K temperature interval, quite satisfactory results are obtained for the mixtures investigated.
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TL;DR: A group contribution equation of state called PSRK (Predictive Soave-Redlich-Kwong) is proposed in this article to predict vapor-uquid-equilibria (VLB) for a large number of systems without introducing new model parameters.
636 citations
TL;DR: The development of van der Waals cubic equations of state and their application to the correlation and prediction of phase equilibrium properties is presented and analyzed in this paper, with a brief account of the contributions to equation of state development during the years before van derWaals.
Abstract: The development of van der Waals cubic equations of state and their application to the correlation and prediction of phase equilibrium properties is presented and analyzed. The discussion starts with a brief account of the contributions to equation of state development during the years before van der Waals. Then, the original equation proposed in the celebrated thesis of van der Waals in 1873 and its tremendous importance in describing fluid behavior are analyzed. A chronological critical walk through the most important contributions during the first part of the 1900s is made, to arrive at the proposal that I consider to be the most outstanding since van der Waals: the equation proposed by Redlich and Kwong in 1949. The contributions after Redlich and Kwong to the modern development of equations of state and the most recent equations proposed in the literature are analyzed. The application of cubic equations of state to mixtures and the development of mixing rules is put in a proper perspective, and the ...
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TL;DR: There are many alternative equations of state capable of calculating the phase equilibria of a diverse range of fluids as mentioned in this paper, from cubic equations for simple molecules to theoretically-based equations for molecular chains.
Abstract: Progress in developing equations of state for the calculation of fluid-phase equilibria is reviewed. There are many alternative equations of state capable of calculating the phase equilibria of a diverse range of fluids. A wide range of equations of state from cubic equations for simple molecules to theoretically-based equations for molecular chains is considered. An overview is also given of work on mixing rules that are used to apply equations of state to mixtures. Historically, the development of equations of state has been largely empirical. However, equations of state are being formulated increasingly with the benefit of greater theoretical insights. It is now quite common to use molecular simulation data to test the theoretical basis of equations of state. Many of these theoretically-based equations are capable of providing reliable calculations, particularly for large molecules.
399 citations
TL;DR: Boukouvalas et al. as discussed by the authors developed a new mixing rule, a linear combination of the Vidal and Michelsen rules, for the attractive term parameter in cubic equations of state (EoS) has been developed, coupled with a translated and modified Peng-Robinson EoS and the original UNIFAC, which leads to the LCVM model which provides successful prediction of vapor-liquid equilibria of nonpolar and polar systems at low and high pressures.
239 citations
TL;DR: In this article, a new experimental system of biomass gasification in supercritical water was built in SKLMF, and a comprehensive thermodynamic analysis, including chemical equilibrium in the reactor, gas-liquid equilibrium in high-pressure separator, exergy and energy analysis of the whole system, was conducted.
234 citations