Notices
Results 1 to 9 of 9
Like Tree1Likes
  • 1 Post By Warron

Thread: Fractionating process to obtain fractions with a boiling point between -160 C to +20 C ?

  1. #1 Fractionating process to obtain fractions with a boiling point between -160 C to +20 C ? 
    Forum Freshman
    Join Date
    Nov 2013
    Posts
    44
    I know about fractional distillation columns for separation of crude oil. I assume this must be for separating oil which are gases at room temp.

    What is this process called and how does it work?


    Thanks.


    Reply With Quote  
     

  2.  
     

  3. #2  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,067
    Quote Originally Posted by JackAnimated View Post
    I know about fractional distillation columns for separation of crude oil. I assume this must be for separating oil which are gases at room temp.

    What is this process called and how does it work?


    Thanks.
    So far as I know it is essentially the same, except that you have to liquify the gas mixture first by cooling: Air separation - Wikipedia, the free encyclopedia


    Reply With Quote  
     

  4. #3  
    Forum Cosmic Wizard
    Join Date
    Dec 2013
    Posts
    2,408
    The towers work by condensing hot vapours after they have been heated far above their boiling points. As the vaporized petrolium profuct goes up the tower the temperature drops.
    The heavier tarlike products condense first near the bottom of the tower.

    It can get much more complicated with cracking towers, vacuum towers, stripper columns, cokers, hydrotreaters, hydrogen furnaces and catalytic reformers.

    Edit. Oh, what are they called? Frac towers.

    (How much detail do you need?)
    Last edited by dan hunter; May 3rd, 2014 at 05:56 PM.
    Reply With Quote  
     

  5. #4  
    Forum Sophomore
    Join Date
    Jan 2014
    Posts
    106
    Your question is not stated clearly.

    As exchemist says, fractionation of low boiling materials is much the same as fractionation of higher boiling fractions, except the process is carried out at low temperatures. Air is separated into nitrogen, oxygen and argon by this type of process. The air is first liquified.
    Reply With Quote  
     

  6. #5  
    Forum Freshman
    Join Date
    Nov 2013
    Posts
    44
    Would a fractionating column be used in this instance?
    Reply With Quote  
     

  7. #6  
    Forum Sophomore
    Join Date
    Jan 2014
    Posts
    106
    Quote Originally Posted by JackAnimated View Post
    Would a fractionating column be used in this instance?
    Yes. The physics is fundamentally the same. The materials are selected to deal with the low temperatures. Aluminium alloys are used for air separation.
    Reply With Quote  
     

  8. #7  
    Forum Freshman
    Join Date
    Nov 2013
    Posts
    44
    The question I've been set asked for a labeled diagram to accompany my explanation. I cannot find one on the internet. Should I just draw a standard fractional distillation column, but with different temperatures and fractions?
    Reply With Quote  
     

  9. #8  
    Forum Sophomore
    Join Date
    Jan 2014
    Posts
    106
    I didn't realise this was an assignment question. Try using the term 'cryogenic fractionation'.
    dan hunter likes this.
    Reply With Quote  
     

  10. #9  
    KJW
    KJW is online now
    Forum Professor
    Join Date
    Jun 2013
    Posts
    1,392
    A discussion about fractional distillation wouldn't be complete without mentioning theoretical plates.
    There are no paradoxes in relativity, just people's misunderstandings of it.
    Reply With Quote  
     

Similar Threads

  1. boiling point and melting point examples
    By apjayanap in forum Chemistry
    Replies: 1
    Last Post: August 29th, 2010, 03:50 AM
  2. Replies: 1
    Last Post: May 20th, 2010, 08:24 PM
  3. Boiling Point
    By aw33093 in forum Chemistry
    Replies: 4
    Last Post: December 4th, 2009, 02:07 AM
  4. The bubble and the Boiling Point
    By PritishKamat in forum Chemistry
    Replies: 18
    Last Post: November 18th, 2009, 07:59 PM
  5. Why things have X boiling point.
    By Kasc in forum Chemistry
    Replies: 2
    Last Post: October 27th, 2007, 02:09 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •