×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Azeotropic data for Decalin

Azeotropic data for Decalin

Azeotropic data for Decalin

(OP)
Looking for Azeotropic data for a decalin (DecahydroNapthalene) / water system? Any idea where  might be able to find information such as the pressure at the low boiling azeotropes for decalin / water at 200C (and 300C). Also would need to know the w/w ratios etc ...

Anyone know of an online resource, where I might look to find this information?

Read the Eng-Tips Site Policies at FAQ731-376  

RE: Azeotropic data for Decalin

(OP)
No one has any ideas? :( might have to use HYSYS or ASPEN to produce at least a number I guess.

Read the Eng-Tips Site Policies at FAQ731-376  

RE: Azeotropic data for Decalin

Hi, ColourfulFigsnDiags:

All Aspen Plus or Hysys could do for you is to use the UNIFAC group contribution method for estimating the VLE behavior.  Unfortunately, UNIFAC is often not very good for large molecules such as decalin that have a large multiplicity of the same main group (in this case the hydro).  This is because the mixture VLE data used to build the UNIFAC database contains few such instances.  So, you could end up with very inaccurate predictions and not know it.

Generally, I would recommend measuring the mutual solubility experimentally in such situations, fitting temperature-dependent UNIQUAC parameters based on this LLE data, and then estimating the VLE using the same UNIQUAC parameters.  If the compounds are completely miscible, you would have to (a) measure at least some VLE data, or (b) obtain the infinite dilution activity coefficients using either differential ebulliometry or gas chromatography.  (In this instance I doubt the chromatography idea would work as decalin is very non-volatile).  The very much simpler differential ebulliometry technique was developed by Professor Charles Eckerdt over 20 years ago.

Hope this is all clear.  A good reference for understanding the theory is "Computer Calculations for Multicomponent Vapor-Liquid Equilibria" by Prausnitz et al (Prentice Hall).

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources