Predictive Soave-Redlich-Kwong PSRK

The UNIFAC model has also been combined with the predictive Soave-Redlich-Kwong (PSRK) equation of state. The procedure is most completely described (with background literature citations) by Horstmann et al. [Fluid Phase Equilibria 227 157-164 (2005)]. 

In this study, the phase equilibrium in the binary mixtures that are expected to be found in the flash distillation was modeled with the Predictive Soave-Redlich-Kwong (PSRK) equation of state [4], using modified molecular parameters r and q. Five binary ethanol + congener mixtures were considered for new yield values for parameters r and q. The congeners considered were acetic acid, acetaldehyde, furfural, methanol, and 1-pentanol. Subsequently, the model was validated with the water + ethanol binary system, and the 1 -pentanol + ethanol + water, 1-propanol + ethanol + water, and furfural + ethanol + water ternary systems. 

The Predictive Soave-Redlich-Kwong (PSRK) Equation of State A Proposal for Modeling the Flash Vessel... 

This work proposed the use of the Predictive Soave-Redlich-Kwong (PSRK) model to describe the phase equilibria in the flash distillation, using modified molecular parameters r and q for ethanol. In this way, the PSRK equation of state becomes more empirical, but keeps the predictive capabilities of the model. Furthermore, the introduction of new molecular parameters r and in the UNIFAC model gives more accurate predictions for the concentration of the congener in the gas phase for binary and ternary systems. 

If no experimental data are available gas solubilities can be predicted today with the help of group contribution equations of state, such as Predictive Soave-Redlich-Kwong (PSRK) [43] or VTPR [44]. These models are introduced in Sections 5.9.4 and 5.9.5. 

Predictive Soave-Redlich-Kwong (PSRK) Equation ofState... 

An approach to overcome the above mentioned difficulties was the PSRK (Predictive Soave-Redlich-Kwong) equation developed by Holderbaum and Gmehling in 1991 [49, 50], based on the Soave-Redlich-Kwong equation 43]. Its main progress is the use of mixing rules (see Chapter 4) for a significant improvement of the description of mixtures with polar compounds. For the improvement of the pure component vapor pressures, an -function, individual for every substance, was introduced. In the PSRK equation, the Mathias-Copeman approach [51] is used, which is a polynomial extension of the Soave a-function (Eq. (2.163)) ... 

Hoderbaum and Gmehling proposed the Soave-Redlich-Kwong equation of state be combined with UNI FAC and produced the Predictive Soave-Redlich-Kwong (and given the acronym PSRK) equation for which a(x) is given by... 

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