pw0908
commented
7 months ago Hi! A few things to note:
- The first paper you refer to uses PCP-SAFT which is available in Clapeyron (you'll need to specify the dipole moment in those cases).
- It appears that the approach in both papers, as far as the induced association is concerned, is identical, where both use the Wong-Sandler combining rule for cross-association.
- In the first paper, in the case of Chloroform, the visual they've included is a bit misleading. Chloroform is not a proton donor (that C-H bond is not polar enough to induce hydrogen bonding) but it is an electron donor (the C-Cl bond is very polar and can induce hydrogen bonding with the O-H on the alcohols). As there are three of these, you can account for them as e sites.
With those two points in mind, the 'correct' way to set-up the model would be as follows:
julia> model = PCPSAFT(["ethanol","chloroform"];userlocations=(;
Mw = [46.069,119.37],
segment = [2.3827,2.5038],
sigma = [3.1771,3.4709],
epsilon = [198.24,271.625],
dipole = [0.,1.04],
n_H=[1,3],
n_e=[1,0],
epsilon_assoc = Dict(
(("ethanol","e"),("ethanol","H")) =>2653.4,
(("ethanol","e"),("chloroform","H")) =>1326.7,
),
bondvol = Dict(
(("ethanol","e"),("ethanol","H")) => 0.032384,
(("ethanol","e"),("chloroform","H")) => 0.032384,
)
))
PPCSAFT{BasicIdeal} with 2 components:
"ethanol"
"chloroform"
Contains parameters: Mw, segment, sigma, epsilon, dipole, dipole2, epsilon_assoc, bondvol
julia> bubble_temperature(model,1e5,[0.8,0.2])
(342.47489071408995, 6.664468359724602e-5, 0.027564634355155437, [0.5689549253463148, 0.43104507465368525])The values above appear to correctly reproduce the results from the paper although I haven't rigorously tested this.
I hope this helps!
1578jason
longemen3000
Hi, I'm trying to use the SAFT EOS to do some calculations on "induced solvation", where only one compound is self-associating but can interact with another compound. I tried to do the calculations as described in the following two articles, but was confused about how to define these systems in Clapeyron, so I come to you for help: Article 1 https://doi.org/10.1021/jp072640v Article 2 https://doi.org/10.1021/ie050976q In the first article, the authors make the following assumption: • The association energy parameter of the non-self-associating component is set to zero. • The association volume parameter of this component is assumed to be equal to the value of the associating component in the mixture. Is it represented in Clapeyron as something like this? (Take ethanol and chloroform as example)
In the second paper, the authors set the cross-association energy to half of the self-associating component, and take the cross-association volume and kij as two adjustable parameters, whether it is expressed in the following form?(Specify only one pair of cross-association parameters and regress cross-association volume )