Cubic Plus Association
Cubic Plus Association
(OP)
I have been investigating applications of the Cubic Plus Association model
specifically the two variants available in Prode Properties,
one based on Soave Redlich Kwong and another on Peng Robinson.
As far as I can see these return similar results in VLE tests (mixtures of hydrocarbons+water), but I have a limited number of interaction coefficients for water-hydrocarbons and that could be a limit for my tests.
Prode includes a data regression procedure able to regress VLE/LLE/SLE data points but I have not the required experimental VLE data for hydrocarbons/water (of course I do not wish to estimate VLE with the UNIFAC option available in Properties),
my question is, does anyone know of free resources for experimental VLE data for water/hydrocarbons?
That would be very useful for all us working in natural gas industry.
specifically the two variants available in Prode Properties,
one based on Soave Redlich Kwong and another on Peng Robinson.
As far as I can see these return similar results in VLE tests (mixtures of hydrocarbons+water), but I have a limited number of interaction coefficients for water-hydrocarbons and that could be a limit for my tests.
Prode includes a data regression procedure able to regress VLE/LLE/SLE data points but I have not the required experimental VLE data for hydrocarbons/water (of course I do not wish to estimate VLE with the UNIFAC option available in Properties),
my question is, does anyone know of free resources for experimental VLE data for water/hydrocarbons?
That would be very useful for all us working in natural gas industry.





RE: Cubic Plus Association
However for CPA there are correlations to estimate kij values of water-hydrocarbons, one is
kij = -0.026 * C + 0.1915
where C is the carbon number
RE: Cubic Plus Association
I agree that Cubic Plus Association is very good for natural gas applications, it gives accurate results for hydrocarbons, water, glycols, alcohols, amines etc.
I think Prode does a good job including this model in the free version available in the web.
RE: Cubic Plus Association
DECHEMA, DDB, (GPA)
unfortunately these are not free.
RE: Cubic Plus Association
It seems that they do not generate VLE experimental data themselves the way DDB does, but they collect published data into a well indexed data base. The menu does not work in Firefox (v12) on my computer but it is probably something that I have done wrone in the settings. It works well in IE (v8).
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