2 replies to this topic

[djgoran]

Hello everybody!

First off all I wish you all happy and successful New year.
I'm newbie in HYSYS and have a problem in modeling of the gas absorption column.

I need to model (existing) gas absorption column for recovery of dimethylformamide from exhaust air, with data as follows (to proof that column doesn't polute environment):

- Waste Gas entering into column:
20.000 m3/h Air + DMF (250 kg/h DMF) @ 90 - 140 deg C


- Solvent entering into column:
1.3 m3/h demi water @ 35 deg C and 1 bar abs

Absorber has 15 valve trays.

After passing through absorber waste gas (now clean waste air) goes to atmosphere, and demi water enriched with
DMF goes into a tank.
DMF is completely miscible with water

I model absorption column in HYSYS and received unexpected result (although column converged) - all DMF goes to atmosphere, i.e. gas output is (almost) same as a gas input.

I used PR EOS, and mixer HYSYS operation to mix DMF and air to form the Waste Gas.

Obviously newbie error, but I couldn't go further.

Any guidelines and suggestions regarding above mentioned problem will be appreciated.

If You need some more information let me know.

Thank You all in advance and best regards

Goran

goran.djurdjevic@inet.hr

[joerd]

Good observation. If you look on the binary interaction parameters page (Basis environment) you will see that all the interaction parameters for DMF are 0.0. This is obviously not right, and PR EOS is therefore not the right package. Try using NRTL instead.

[djgoran]

Good observation. If you look on the binary interaction parameters page (Basis environment) you will see that all the interaction parameters for DMF are 0.0. This is obviously not right, and PR EOS is therefore not the right package. Try using NRTL instead.

Many thanks Joerd !

The results now are in expected range.

Best regards

Goran