4 replies to this topic

[eonation]

Hello everyone, I'm trying to design a de-ethanizer to separate methane,ethane from C3+. I have already build the tower using VMGsim. Now I'm trying validate the values I got from this software through hand calculation. Im planned to do this using macabre-thiele method by creating a pseudo-binary system of ethane vs propane. The problem is that I can't seem to find the VLE data for this system. Usually, I could use the raoults law, antoine equation and daltons law to generate a set of VLE data but I can't since dalton's law only applies for low-med pressure system. Whereas the de-ethanizer column I'm designing is at 2600 kPa operating pressure. Is there another way that I can generate VLE data for ethane vs propaneat high pressure?

 

Thank you 

[PingPong]

You do realise that such hand calculations will not be very accurate?

 

Anyway, if you really want, you can use charts to obtain (estimated) equilibrium K-values for ethane and propane.

 

Well-known are the DePriester charts which you can find in Perry, or on the internet.

 

The API Technical Data Book also contains some charts to estimate K-values.

 

And so does the GPSA databook.

 

Note that K = x/y

and relative volatility of ethane to propane is: α = K_C2 / K_C3

[srfish]

eonation,

 

You could use the convergence pressure method. You can find this in the Natural Gas Processors Suppliers Association  (NGPSA) Engineering Data Book.

[Napo]

Eonation,

 

You can check the article: "An equation to relate K-factors to pressure and temperature", by Mark McWilliams, in Calculations&Shortcut Deskbook, published by Chemical Engineering, p. 102-104.

 

Also, Principles and Modern Applications of Mass Transfer Operations by J. Benitez, 1st ed., 2002, Ch. 6: 6.10 Mixtures of light hydrocarbons: m-value correlations, p. 370-371.

 

With this equations you can do a spreadsheet.

 

I hope help you.

 

Napo.

[Padmakar Katre]

Hello everyone, I'm trying to design a de-ethanizer to separate methane,ethane from C3+. I have already build the tower using VMGsim. Now I'm trying validate the values I got from this software through hand calculation. Im planned to do this using macabre-thiele method by creating a pseudo-binary system of ethane vs propane. The problem is that I can't seem to find the VLE data for this system. Usually, I could use the raoults law, antoine equation and daltons law to generate a set of VLE data but I can't since dalton's law only applies for low-med pressure system. Whereas the de-ethanizer column I'm designing is at 2600 kPa operating pressure. Is there another way that I can generate VLE data for ethane vs propaneat high pressure?

 

Thank you 

 

Hi,

Search in Google, I am sure you should get some open literature on this topic. You can also try with process simulator which can do this for you.