Jump to content

  • Log in with Facebook Log In with Google      Sign In   
  • Create Account


ChExpress Blog - 10/15/14

Read the latest news from the chemical industry in Christa's blog.

Featured Articles

Check out the latest featured articles.

File Library

Check out the latest downloads available in the File Library.

New Article

Product Viscosity vs. Shear

Featured File

Air Vessel Sizing for Water Hammer Prevention

Scf Conversion To Mole Fraction


This topic has been archived. This means that you cannot reply to this topic.
4 replies to this topic
Share this topic:

#1 z_kapetaki

z_kapetaki

    Brand New Member

  • Members
  • 5 posts

Posted 16 August 2010 - 10:35 AM

Hi all,

I have the solubility of CO2 in Selexol given in SCF/USGal and I am trying to take out of that mole CO2/mole Selexol. My concern is about the SCF conversion. Do I have to include the temperature term (60 oF) for the SCF to have STP at least as a first result? I would appreciate if anyone could help.

#2 Zauberberg

Zauberberg

    Gold Member

  • Store Customers
  • 2,193 posts

Posted 16 August 2010 - 11:31 AM

I'm not sure if I understood your question well, but if conversion from SCF to Sm3 is concerned it is very much straightforward since both refer to standard conditions (101.325 kPa, 15.6 degC).

For converting from SCF/gal to mol/mol you need Selexol density and Moleculer weight.

#3 Art Montemayor

Art Montemayor

    Gold Member

  • Admin
  • 4,870 posts

Posted 16 August 2010 - 12:28 PM




Having dealt with CO2 removal processes for a long time, I believe I know what you are faced with. You are probably trying to convert a CO2 loading given in normal USA units as “SCF/USGal” to “CO2 moles/mole of Selexol”. You need this to relate to published data. Am I correct?

If so, then you should take into consideration that for a gas there are 379.48 ft3/lb-mol at 60 °F and 14.696 psia. These are normal USA units – and they have nothing to do with the term “Normal” as employed in Europe. I try to shy away from using the term “standard”. Every body and his brother has his own “standard” conditions – and more are being fabricated every day. It is safer and more prudent to simply always refer to your base temperature and pressure (you failed to state that you are referring to atmospheric pressure – therefore, I base myself on the stated 14.696 psia).

As Zauberberg states, this is only half of the job. You also need to know the density and the molecular weight of the Selexol solution that you are employing.


#4 Zauberberg

Zauberberg

    Gold Member

  • Store Customers
  • 2,193 posts

Posted 16 August 2010 - 01:28 PM


Every body and his brother have their own “standard” conditions – and more are being fabricated every day.


:P Very true, so it is always recommended to quote exact temperature and pressure to which the term "standard" is referred to. Most often - at least in Europe and in projects/plants which have adopted SI units - both "Standard" and "Normal" refer to the same atmospheric pressure 101.325 kPa; "Standard" temperature can be either 15.6 degC or 20 degC, while "Normal" temperature is 0 degC. But, as you said Art, without quoting P,T values, the words "Standard" and "Normal" are quite vague.

#5 z_kapetaki

z_kapetaki

    Brand New Member

  • Members
  • 5 posts

Posted 17 August 2010 - 04:48 AM

Hello Art,

This is exactly what I am trying to do!

Thank you very much for the reply. So in that case, you think it's more accurate to calculate moles in 60 oF and 1 atm and then make the conversion to any temperature. The densities, though, usually are given in NTP (25 oC and 1 atm). Thank you both for the posts.




Similar Topics