2 replies to this topic

[lnbsak]

 

I am using Aspen plus to simulate a process where we have to separate the product and undesired product in Separation 1 column and Separation 2 column equipment respectively.

Both of the separation columns use water, so they have some amount in their respective outlet stream based on the equilibrium of the top stage of the respective column.

So that causes different water concertation in streams 101 and 103.

https://ibb.co/vhYFD7p

Now in order for two recycle streams to converge I need to have the water concentration balanced. How can I, in this situation? Purge? But that causing a large amount to be purged.

Would appreciate any advice.

Edited by lnbsak, 05 June 2021 - 07:29 PM.

[Pilesar]

There is not enough information supplied to give you a definite answer. If 'some amount' of water is insignificant to the process and only causes numerical issues, then you can remove the water component from a stream and not recycle it. If 'some amount' is important to the recycle and you can estimate the amount of water, then add a fixed amount of water back as a separate stream. These are just techniques you might use. All simulations are wrong in some way and the goal is to make them useful for your purposes. When you achieve the goal, there is no reason to fiddle further with the simulation.

[lnbsak]

Thank you so much sir for your answer. Actually I was little worried as there is one compressor in the recycle stream. So my thought was do we have to use special moisture controlling equipment. If yes how much water should be in the stream in the first place?

Edited by lnbsak, 09 June 2021 - 03:32 AM.