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Homework Help: Dme + h2o

  1. Nov 25, 2008 #1
    I've been searching for a DME + H2O boiling point composition curve. Can someone help me here or give me a clue how to calculate the curve?
     
  2. jcsd
  3. Nov 25, 2008 #2

    Borek

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    Staff: Mentor

    These things are determined experimentally, so you have to search literature.
     
  4. Nov 26, 2008 #3
    I think I saw once that there was a program where you would input molecules and magically you could get a component curve out of it.

    It could be that they were using correlations to set up this component curve based on activity coefficients, isn't this true?

    It has been 5 years now, so my mind is blurry at this moment.

    Edit: I remember things like Uniquac, unifac, nrtl and you had to use one of them specifically when dealing with a certain mixture. But I forgot it all by now... I'll have to dig it up again.
     
    Last edited: Nov 26, 2008
  5. Dec 3, 2008 #4
    Just to update the status: I've found a free software VLE calculator tool where you can input Antoine coefficients, molecular weight and density of the components. You can then calculate the composition curves with UNIFAC. It's a pretty awesome thing to use!
     
  6. Dec 3, 2008 #5

    Borek

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    Staff: Mentor

    Coefficients are found experimentally and Antoine equation usually doesn't work for the entire pressure/temperature range. In other words - coefficients itself are temperature dependent. So you better treat results of these calculations with care. But they are better than nothing :smile:
     
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