Calculating residual enthalpy and entropy for vapor-liquid equilibrium mixtures

[maistral]

Good day.

I have no idea how to calculate mixture residual enthalpies/entropies. I have searched all over the internet and yeah, I keep on finding the pure-fluid residual enthalpy calculations.

Is there ANY possible source here where an algorithm for residual enthalpy calculations for MIXTURES (for VLE) is shown? Thanks!

 

[Chestermiller]

Good day.

I have no idea how to calculate mixture residual enthalpies/entropies. I have searched all over the internet and yeah, I keep on finding the pure-fluid residual enthalpy calculations.

Is there ANY possible source here where an algorithm for residual enthalpy calculations for MIXTURES (for VLE) is shown? Thanks!

It might be in Smith and Van Ness.

Chet

 

[maistral]

Oh hi again chet! :D Happy to see you.

SVNA tells me to apply linear mixing rules on the critical parameters to calculate an effective critical parameter, then use these parameters to calculate the departure enthalpy as if it was a single fluid.

Searching for the validity of such steps, I encountered some codes and texts that seemingly apply a quadratic mixing rule on the alpha function? I have no idea how they did it. I'm totally at a loss, I have no idea what to do. I need some enlightenment. Thanks a lot!

 

[Chestermiller]

I think chapters 11 and 14 have what you want, where they work with the second virial coefficient and have a theoretically based mixing rule, based on statistical thermodynamics.

Chet

 

[maistral]

Oops, forgot to specify. I wanted the EOS methods, not the virial coefficient ones, sorry.

 

[Chestermiller]

Oops, forgot to specify. I wanted the EOS methods, not the virial coefficient ones, sorry.

They give an eos example in ch 14.

 

[maistral]

Thanks. Will try and give a look again, I may have been too tired and have missed it o_o thanks!