Batch Disillation 1

[crdlee]

I want to simulate batch distillation and estimate column sizing. but I don't have batchfrac(or batch distillation) license. I just have A+ and Aspen Dynamics license.
How can I do it?

 

[FOllivier]

You can't. You really need Batchfrac for it !

 

[StoneCold]

crdlee
If you think of the continuous column as a snapshot of the batch column (enriching section only) then you could make some stepwise solutions for the batch distillation using varying feed compositions.
Change the feed composition based on a mass balance around the column after xx minutes.
Then flash the new liquid composition from the material balance and feed it to the column. I think if you keep repeating this process, assuming that the distillation changes stepwise instead of the true gradual change that you won't be that far off.
The time xx will be dependant on the size of the column and how fast the compositions are changing.

Maybe someone else will have a more elegant solution.

Goodluck
StoneCold

 

[Phil31]

You can also try another software dedicated to batchcolumn simulation. We, at ProSim SA have developed a specific, easy to use and reliable software for this kind of operation (software named BatchColumn). It is the only software as i know which is able to simulate the startup (filling of the column) operation. It can handle complex simulation scenario and offers some design features (hydraulic calculations). It also contains a complete thermodynamic library for handling many types of mixtures. Don't hesitate to visit our web site for more information at www.prosim.net.

 

[sshep]

This might be the same as what Stonecold is suggesting, but instead of viewing your process as a batch distillation with time as the independent variable, consider it as a sequence of continuous unit operations with cumulative vapor/feed ratio as your independent variable. Pass the residue through as many discrete steps in series as you feel is needed to approximate the batch process.

I have used this technique several times myself and it seems reasonable. just a thought- sshep