VLE Info!

[vaimar]

I mistakenly posted this in the plant design operations:

I just recently graduated and I have been asked to design an absorption column to absorb an acid gas and H2O (liquid).

I know the flowrate for the acid gas; however, I do not know any other information. If I had a VLE diagram it would be easy to determine the number of stages from the stripping section. How do I go about constructing a VLE diagram with minimal information? I have Antoine coefficients and I have the operating pressure and temperature (which is atmospheric). Any information will be helpful.

 

[siretb]

Antoine coefficients will not help much. Henry's coefficient would be better. The water carboxylic acid will be highly non-ideal anyway. And so will be SO2 or HCl/water.
I would expect that the entire process will be mass transfer limited. What you need is a diffusivity, so as you can use correlations like Onda's or Billet's correlations for packing.
Or get from a supplier a typical, overlall HTU.

If what you mean by acid gas is SO2/SO3/HCl in N2/O2/CO2, then in many a case you are gas-side mass-transfer-limited. For SO2, if the concentration gets high (say more than 2000ppv, you may be liquid-side mass-transfer-limited.
Be aware that these pollutants need some reagent to be effectively screubbed (NaOH, CaCO3, Ca(OH)2, ...)

If you need more help be more specific about your system

 

[ajs1972]

You can see on the book "Unit Operations of Chemical Engineering" from Warren L. Mc Cabe, Julian C. Smith and Peter Harriott (Mc Graw Hill) the equations for calculate it (gas absorption chapter).