VLE for acetone-methanol and water 1

[MaxPlanck]

Hi everyone,

I'm trying to design a distillation column which will separate acetone from methanol. It is an extractive distillation with water as entrainer.

I'm searching now for a VLE for acetone-methanol-water..without any luck..

Can someone help me please?

Thanks,
Carlo

 

[wfn217]

ChemSep Lite may help:

http://www.chemsep.org/

 

[researchchem]

i have a pdf for this data .....if u have an email i will send u ....

 

[researchchem]

which software u r going to use for the design....i am curious....

 

[MaxPlanck]

Hi,

I`ve to write a paper for a certain field in my last year at the university (chem. engineering).
W`ll first try to calculate the column manual, subsequent with aspen+. To be more specific, it`s a experimental extractive rectification column without any known characteristics.

Thanks everyone for the reply`s!
Carlo

carlolammers@gmail.com

 

[UmeshMathur]

Have you checked the DECHEMA data book series for experimental VLE data? This is a voluminous set of books that lists all experimental data reported in the open literature that have been measured up to some date preceding the publication. These books are expensive, but most respectable libraries carry them. Also, they include VLE regression results for the more common activity coefficient models.

I feel almost certain that the binary mixtures in your system have been measured. Once you get the data, you would re-regress the binary interaction parameters (in Aspen Plus, for your chosen activity coefficient model - I would assume you're considering Wilson, NRTL, or UNIQUAC), since the vapor pressures might not quite agree with those used to regress the data in the DECHEMA books. The multicomponent VLE calculations are based solely on the regressed binary VLE parameters.

If, by some bizarre chance, the data for the constituent binaries is not available, all hope is not lost. You could use the UNIFAC group contribution method to estimate the missing VLE. This is available as an option in Aspen Plus; however, as you should know, UNIFAC estimates of infinite dilution activity coefficients can be off by 30% or more and, therefore, your column simulation may be significantly in error.

 

[stevethermo]

The DECHEMA books have regressed parameters for the binary systems. These books are a major source for parameters included in the databanks of most process simulators.

Another source of data is the Korea Thermophysical Properties Databank, KDB, which is located on the web at:

http://www.cheric.org/research/kdb/

or alternatively at:

http://infosys.korea.ac.kr/kdb/kdb/hcvle/hcvle.php

Best of luck

 

[MaxPlanck]

I found some experimental VLE data in the DECHEMA data book series. Thanks for helping!

But does anyone know where to find some specific data or can explain me how to calculate:
1)you keep the mole fraction of water constant (e.g. 0.1), what becomes the VLE for acetone-methanol.
2)the same but now the mole fraction of water = 0.2
3)mole fraction water = 0.3
....

Thanks,
Carlo

 

[UmeshMathur]

You need to study the basics of VLE thermodynamics if you want to learn to do such calculations yourself. I suggest the following book by the recognized maestros in this field:

"Computer Calculations for Vapor-Liquid and Liquid-Liquid Equilibria" by Prausnitz, et al (Prentice Hall, 1980).

This book contains voluminous code for doing such calculations - probably too much for someone who doesn;t have the background anyway. That's why such procedures are built into most commercial simulators and are not difficult to use.