3 replies to this topic

[quangkhoa90]

Hi everyone,

 

I am a master student, I am working on thermal couple column simulation.

While simulating a Petlyuk column, I face up to a problem. 

The pre-fractionator has neither reboiler nor condenser, then the first time when the multicomponent feed is introduced to this column, the separation doesn't occur since there is no heat supplied. Then the Petlyuk configuration cannot be simulated.

 

How can I fix this ? There must be a way to simulate a Petlyuk column on Aspen.

 

Thank you for your help.

 

Quang Khoa LE 

Attached Files

•  PETLYUK.png   8.95KB   28 downloads

[AlertO]

hi quangkhoa

Petlyuk column need more specifiaction inputs to the model. So your column may be under-spec now. Check you specification whether they achieve the DOF requirement.

Note: the heat duty at prefractionator is unusually required for input.

hope this may help you

[quangkhoa90]

Hi Alert

 

Thank you very much for your answer.

It works better to use the Multifrac model (instead of a series of Radfrac) with an even vapor split to the second tower- this simulates the vapor distribution at the partition.  

But it seems not easy to make the model converged. 
In fact, I have been trying to find the combination of heterogeneous azeotropic distillation and Petlyuk column.
For the Radfrac column, we can specify the Azeotropic convergence option for the column, but I didnot find out how to do it for the Petlyuk column. I think it may be important to mention it in the column spec option.

Otherwise, the flowrate of liquid and vapor stream back to the prefractionator from the main column need to be specified. I have no idea how to give a good estimation. Do you know any papers about this ?

 

if you have any suggestion, I would like to know that.

 

Regards

 

Quang Khoa

[AlertO]

hi quang khoa

You are correct the flow rate is a necessary parameter which is strongly required for Petyuk Column. For your case, i think the problem to combine the azeotropic and Petlyuk column is the petlyuk column model (in ASPEN) is not designed for azeotropic separation. i don't say it cannot be applied, but it may be difficult and need some consultance from experienced guy in this model.

now i am not able to use ASPEN PLUS, so the guidance is limited in general matter.

Attached Files

•  Petlyuk Column.pdf   1.08MB   187 downloads