2 replies to this topic

Hello..I am looking for UNIFAC-VLE Subgroup Parameters Table online but cant find any..where can I get it?

By the way..how should I categorize C=C compound for example butene and compound like dimethylformamide when using UNIFAC VLE method?

Thanks for helping...

[breizh]

Phantom,
let you try Perry Chemical engineering handbook .
Google should be a good support too .
Hope it helps
Breizh

[MrShorty]

If you must have an internet based resource, Google (or other search engine) is definitely the place to start. The first result I got linked to Wikipedia, which then had a link to someone with a table of parameters.

However, I'm not real fond of internet based UNIFAC tables. It seems that the vast majority of those that I found were incomplete or based on older publications. It also appears from your question about olefin groups and amide groups (assuming DMF refers to dimethylformamide) that you have little or no experience working with UNIFAC. Internet resources, even when they have a good table of parameters, don't always explain very well how to use UNIFAC.

If you can find it, I would recommend you find a textbook resource instead of an internet based resource. A favorite among many ChE's is The Properties of Liquids and Gases by Poling and Prausnitz (4th or 5th edition, I don't think the 3rd or earlier editions discussed UNIFAC. 5th edition will have the most updated groups and parameters). A textbook resource will have a complete and accurate list of parameters (at least for the publication date) and it will have a detailed discussion of how to break a molecule down into UNIFAC groups, and then how to use that information to obtain activity coefficients.

Edited by MrShorty, 04 February 2010 - 10:53 AM.