-
|
Dear all, we are developing a Python program for calculating LLE using FeOs for PC-SAFT calculations of chemical potential. In our case: One component has both a negative and positive association site. The other component only has a negative association site. Short Python example: In order to take the induced association in the mixture into account, we would like to explicitly specify epsilon_k_ab and kappa_ab as parameters for the mixture between the two components. However, when creating the equation of state we were not able to find a way for submitting epsilon_k_ab and kappa_ab to the PcSaftParameters object. Short Python example (unfortunately, this formulation didnt work and only adopts k_ij and not the other two parameters): How can we access the modelRecord constructor to submit the binary parameters epsilon_k_ab and kappa_ab for a mixture to the PC-SAFT EoS? Thanks for your help! Best regards, |
Beta Was this translation helpful? Give feedback.
Replies: 1 comment 2 replies
-
|
Hello Moritz, the parameter handling was revised a bit from going from feos 0.8 to 0.9. One aspect we added was to increase the flexibility of the association scheme so that any (well most I guess) kinds of hydrogen bonding arrangements can be modeled. With the current feos version the code would look like this: import feos
hmf = feos.PureRecord(identifier=feos.Identifier(name="HMF"), molarweight=126.11, m=2.72266, sigma=3.83791, epsilon_k=433.125, association_sites=[{"kappa_ab": 0.0052651, "epsilon_k_ab": 2524.61, "na": 1, "nb": 1}])
mthf = feos.PureRecord(identifier=feos.Identifier(name="MTHF"), molarweight=86.132, m=2.7191, sigma=3.6567, epsilon_k=265.09, association_sites=[{"nb": 1}])
pures = [hmf, mthf]
binary = feos.BinaryRecord(id1=feos.Identifier(name="HMF"), id2=feos.Identifier(name="MTHF"), k_ij=0.015, association_sites=[{"kappa_ab": 0.50, "epsilon_k_ab": 1800.0}])
params = feos.Parameters.from_records(pures, [binary])
eos = feos.EquationOfState.pcsaft(params)
display(params)
eos.parameters
|
Beta Was this translation helpful? Give feedback.
-
|
Thank you very much! Thats exactly what I was searching for. This raises a follow-up question: Can I also store temperature-dependent functions directly in eos.parameters? For example, in some applications there are temperature-dependent terms for sigma or k_ij. This would allow me to specify an individual function as a parameter or to specify parameters for standard functions. |
Beta Was this translation helpful? Give feedback.
-
|
Hi this is currently not supported and would be rather difficult to integrate with the automated calculation of temperature derivatives. We have an implementation of ePC-SAFT that has specific temperature-dependent terms for kij and sigma (only for water I think) implemented, maybe that could be of help for you. |
Beta Was this translation helpful? Give feedback.
Hello Moritz,
the parameter handling was revised a bit from going from feos 0.8 to 0.9. One aspect we added was to increase the flexibility of the association scheme so that any (well most I guess) kinds of hydrogen bonding arrangements can be modeled.
With the current feos version the code would look like this: