Excel library for process calc's including distillation

[fmat]

Cette software est tres bon et efficate et bien intégré avec Excel !

[matrenel]

carlo.stenali,
thanks for keeping us updated about this very good product,
I have a question, does CPA model work for VLE only or all phase equilibria etc. calc's ?

[carlo.stenali]

hello matrenel,
my (extended) version has both CPA and SAFT,
I have little experience with SAFT but I utilize quite frequently the Cubic Plus Association model for phase equilibria of water with hydrocarbons,
CPA is available for fugacity (all phases) and volume (density), I believe that also other properties may be available but you should contact the developer for additional information (and cost).

[matrenel]

carlo.stenali,
thanks for the answer, I have been in contact with the developer,
we are more interested in SAFT model (with association),
for SAFT Prode says that different properties as enthalpy and entropy (and derived properties as cp, cv etc.) are available as extended version of the library, which makes Prode Properties very interesting for our company.

[mrbabu]

does anyone have access to Dechema / GPSA experimental VLE data for water/hydrocarbons?
I have been investigating applications of the Cubic Plus Association model in Prode Properties but I have a limited number of interaction coefficients for water-hydrocarbons and no experimental data required by data regression utility available in Prode for estimating interaction coefficients...
Help will be appreciated.

[carlo.stenali]

you can find interaction coefficients for CPA ( Cubic Plus Association ), SAFT etc. in several textbooks as Thermodynamic models for industrial applications.
The availability of reliable vle data for water/light hydrocarbons being not easy, there is a Dechema collection but I do not know where you may find a free copy
Carlo

[hans23]

association models as Cubic Plus Association (CPA) and SAFT are very good for modeling mixtures including components capable of hydrogen bonding, these are a large part of fluids in industrial plants, I mention water, acids, amines, glycols etc.
These models offer many advantages in terms of accuracy, I have compared water-hydrocarbons VLE calculated with CPA and Peng-Robinson Huron-Vidal (and Wong Sandler) and results from CPA are equivalent or better.
Also Prode Properties includes the data regression utility for calculating VLE/LLE/SLE Kij, Lij (both pairs) interaction coefficients.
This is a really good software and I hope that many engineers will consider with interest this alternative...

[mrbabu]

thanks carlo.stenali and hans23,
I have several natural gas streams with mainly methane but with H2S, water and CO2 too,
I have read that CPA (Cubic Plus Association) is better than Peng Robinson and Soave Redlich Kwong,
I wish to compare the two variants (CPA Peng Robinson and CPA-Soave Redlich Kwong) available in Prode Properties,
before to compare results I wish to tune the interaction parameters (there are two intercation parameters Kij and Lij for each binary),
I understand that the best way to calculate these parameters is to utilize the data regression procedure available in Prode Properties but this procedure requires experimental VLE data points which I do not have...
I could use some interaction parameters which I have found but I am not sure about final accuracy.

[carlo.stenali]

I think you are correct about tuning the CPA models with the same experimental data before to compare the results, the data regression procedure available in Prode Properties is good for that,
as said I do know only a few sources (Dechema, DDB, GPA) for VLE data,
there could be some data available from the Korean Thermophysical Properties Databank (see the reply to your post in eng-tips) but I am unable to access that site and I can't confirm.

[hans23]

Hydrate formation curve in Excel

Prode Properties 1.19 includes a utility which allows to calculate the hydrate formation curve directly in Microsoft Excel,
the distribution files include a Excel page hydrate.xls , from this page one can define composition including all common hydrate formers
C1 Methane,
C2 Ethane,
C3 Propane,
C4 n Butane
C4 i Butane
N2 Nitrogen
CO2 Carbon Dioxide
H2S Hydrogen Sulfide

plus inhibitors as Methanol, Ethanol, Glycol and salts (salts require the electrolyte package)

Hydrates modeled according van der Waals and Plateeuw (rigorous, statistical approach) and Cubic Plus Association (CPA) for vapor, liquid phases
A free students version is available from Prode WEB Site

[mpat]

I am calculating with Prode Properties the hydrate formation curve for a natural gas mixture,
components C1...C10 plus N2, CO2, H2S , no inhibitors
I see that resulting values change when
a) I enter only the hydrate formers or all components
b) I specify an amount of water
I would presume that introducing heavy hydrocarbons and water change the fugacity of both gas and liquid phases then affecting the hydrate formation curve.
Is that correct ?
Thank you for help

[carlo.stenali]

with Hydrates model in Prode Properties, you should enter the full composition as the procedure calculates fugacities of different components in gas and liquid (with condensate) phases.
The amount of water has importance for phase equilibria and when inhibitors are present.
Frequently the amount of inhibitors is specified as mass fraction, Prode Properties allows to enter molar or mass fractions so you can convert weight fraction to molar and molar fractions to weight.
Also you can enter fractions in range 0-1 or 0-100.