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[someperson55]

Hello Everyone,

I am senior working on a senior design project in HYSYS, and my group is having an extremely hard time modeling an absorption column in HYSYS, and would love some advice/resources (our teacher referred us to here).
Our project is the production of acetone through the oxidation of propylene, and the absorption column of interest is separating out gaseous components from a product stream.

Our product stream contains (in mol %) from a reaction system

Total: 120 kgmol/hr
39% Acetone
15% Propane
15% water
12% Acetic Acid
7.9% Nitrogen
1-2% of Propylene, Ethylene, Butane, Oxygen, Argon, HCL, few others
And is a vapor at 80 C and 1 ATM
The fluid package we have been using is Electrolyte NRTL in Aspen Properties to account for HCL

The absorption column is running at 1 atm, and will by scrubbed by water at 50 C

We have tried to model this in HYSYS with an absorber, but it runs into issues with multiple liquid phases (water and acetone?). When we try to use the 3-phase absorber, we also have no success.

In specifying the absorption column, we have tried specifying an arbitrary flow rate of water to get it to converge to no avail. When we try to specify a recovery of acetone of 95%, or any other number it also fails to converge no matter what we change. What should the flow rate of the scrubbing water be for the column? We are pretty lost at this point, with no idea how to make the absorber work (we have tried using a flash as a rudimentary separation instead, but it isn’t very good)

What would be a good way to specify an absorber in these conditions (when we only have a product stream, and a desired recovery of product), and how to go about designing it and modeling it in hysys?

Thanks