3 replies to this topic

[Harrys]

I'll like to Know how to determine the binary coefficient of an element in a mixture. Although hysys has quite a number of them in its database. because sometimes it's required to put in the binary coefficient of have a more converge solution

[Andrei]

Harrys,

I do not consider what you want to do an easy task, especially if you want to obtain realistic results. But in the same tine it is something that an advanced user of any simulation program should know how to do it, if the program allows it of course.
What you need first is a deep understanding of how each class of thermodynamic equations work, their applicability and what data is used to generate the interaction parameters.
Than you need experimental data for the components in question.
The last operation is just mathematics, you have to regress the experimental data to obtain the parameters, it is not easy but it's doable.
I am pretty sure that Hysys doesn't allow experimental data regression. As a matter of fact I do not know if Hysys supports user added components, other than the ones already in it's library, for which already has interaction parameters.
I know that Aspen Plus has the possibility of experimental data regression, but I never used it.
For me the easiest is PRO/II, you can create your component, you can generate properties based on structure, you can make interaction parameters and properties regressions. You can create your own component library if you want.
There are other regression programs and Excel add-ons available, you can find a validation spreadsheet on this forum. You just have to serch the Internet.

Good Luck

[smalawi]

Hi,

you need experimental data and do regression in the PVT environment in Latest Hysys / Unisim.

cheers,

sm

[abhi_agrawa]

Harry,

If you have the experimental data, you can regress the same and get the Binary Interaction Parameters (BIP). Aspen Plus does allow you to enter the experimental data and then regress to find the BIPs.

If you do not have the experimental data, then you should search reliable sources for the same. Dechema, Journal of Chemical and Engineering Data (J. Chem. Eng. Data) are a couple of such sources. In Aspen Plus, if you wish you can access Dechema data online (you may have to pay for the data). My experience has been that Aspen BIPs are mostly from Dechema. when you look at the published literature, you may find that for the same system, several people have reported BIPs which are slightly different from each other.

The accuracy of the simulation results is a direct function of the accuracy of the BIPs you use. Be sure to cross-check the BIPs you input. I would say it would not be a very good idea to overwrite the default BIPs in the commercial simulator (if they are there for the system of your interest), unless you have accurate data of your own, because these have been checked by a lot of people and found suitable for several simulations.

Hope this helps,
-abhishek