Soave’s modified Redlich-Kwong equation

Soave s Modified Redlich-Kwong Equation of State... 

This extension is just a first step, however, because it will not be a good approximation at extremely high pressmes. The Redlich-Kwong equation of state is a modification of van der Waal s equation of state, and then was modified further by Soave to give the Soave-Redlich-Kwong (SRK) equation of state, which is a common one in process simulators. Another variation of Redlich-Kwong equation of state is Peng-Robinson (PR) equation of state. 

The alpha function a T) used in the SRK equation is often named Socwe s alpha function. The accuracy of this model was tested by comparing vapour pressures of a number of hydrocarbons calculated with the SRK equation to experimental data. Contrary to the Redlich-Kwong equation, the SRK equation was able to fit well the experimental trend. After Soave s proposal, many modifications were presented in the literature for improving the prediction of one or another property. One of the most popular ones is certainly the modification proposed by (Peng Robinson, 1976) (their equation is named PR76 in this chapter). They considered the same alpha function as Soave but coefficients of the m function were recalculated. In addition, they also modified the volume dependency of the attractive term ... 

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