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[bsfaman]

Good day everyone,
I'm faced with the task of designing a plant for the production of acetone using catalytic dehydrogenation of isopropyl alcohol.

The problem I have arises when I come to the design of the absorption column. This column's purpose is to recover any acetone in the exiting hydrogen stream using a counter current flow of water as a solvent.

My gaseous stream is made up of Hydrogen and Acetone at about 20C and just over 10% Acetone, with a flowrate of 1200kg/h. I'm still trying to figure out what the liquid flowrate required will be.

I was hoping that someone could point me in the direction of some useful equilibrium data for this simple binary system (water-acetone that is). All I have found so far is Henry's Law constant, which I am not sure how to use. As I understand it Henry's law is only valid at low concentrations (when is a solution considered dilute?) and if Henry's law is valid then the equilibrium line would be linear(?).

Any help would be appreciated,
Many thanks in advance!

[chemsep05]

Hey,

We did this project in design class. Basically you have to put in a seperator after the reactor, the top (gas) should go to the absorption column and the bottom to a distillation column. The top stream goes into the absorption column and the hydrogen comes out the top. I believe that we had to use a great deal of water in the column to seperate the Acetone out. You should be able to get over 90% pure hydrogen out the top and practically none out of the bottom. (.001 H2) This is easiest to do in HYSYS. The harder part for most of us was designing the acetone recovery column which had to have 99.99% pure Acetone. Most of our designs recycled the unreacted IPA. Don't forget that the reactor conversion is only about 90% maximum. If you are getting 100% IPA conversion, something is wrong.

Hope that helps!