Dear All, please I really2 need your help , MY REFLUX ABSORBER COLUMN CAN'T CONVERGED

[Rizalhaura]

Dear All, please I very need your help
I tried to simulate crude Oil with 2 different spec. first a crude oil based on design spec, and the second is crude oil from Banyu Urip Well (Indonesia) that will used as actual feed for my plant.
The point is, this refinery wants to compare the product result between crude oil design with crude oil actual.
I have tried to simulate the crude design with refluxed absorber column and have a good result, column converged. I input all operations parameter that state on their engineering document such a temperature, capacity, flow kerosine, diesel, residue, pressure, plate number, etc..all this parameter already determined by them. so far I use this parameter to simulate with crude design, there is no problem appear.

But, the problems appear when I use the second crude oil from Banyu Urip. I have input TBP data, bulk properties data and density data. and the result, hysys show that this crude have a different composition with the design crude. I see that kerosine naphta and diesel already change and has turn into fewer.

When I tried to run the column with the simmiliar spec parameter that I used before, the column is not converged. I see on monitor window, that flow of kerosine from kerosine stripper is increase of error. this error occur because there is a considerable difference between a value estimate that I input and actual value that calculated by HYSYS. I wait until 2000 iteration and column did not converged well. And matrix diagonal zero appear.

I attach the HYSYS file. the design simulation and the actual simulation.
I wish there is HYSYS expertist in this Forum who wants help me. or anyone who has a simmilar problem with me and has found the solutions.

download link file

[link Point to another website Only the registered members can access]
sorry I am not permitted to upload hysys file in this website.

Regards,
Muhammad RIzal
Jakarta, Indonesia

[Rizalhaura]

Pleaase i need your help...help meee

[Rizalhaura]

Help me help me help meee

[Rizalhaura]

heeeelppp

[khalid655]

dear Rizal,
Steps to converge are .
1. first check that d.o.f is zero
2. then go to your crude assay and check how much naphat %, kero % and diesel % reamining is Atmos bottom,
input all theses values .
check the duties and TPA , MPA flow rates and return temps. accordinging to the tray temps.
3. if you have modles whole atmospheric column section as whole , then you need to first converge colum only then whole flow sheet.
I hope your case converges,

[Rizalhaura]

Dear Khalid, thank you for your suggest..
Ok I understand with step 2. I already check the cut blend composition. I also already input these composition to spec.
I have ensure that DOF is a 0 (zero)..
but I still confuse why the tower cannot converged. I dont understand how to adjust the duties, TPA, MPA flow rates and return temperatures according to the tray temps. please if you have a time check my simulation khalid.
May Allah SWT bless you my brother.

Salam,
Rizal

[Rizalhaura]

Dear Khalid, thank you for your suggest..
Ok I understand with step 2. I already check the cut blend composition. I also already input these composition to spec.
I have ensure that DOF is a 0 (zero)..
but I still confuse why the tower cannot converged. I dont understand how to adjust the duties, TPA, MPA flow rates and return temperatures according to the tray temps. please if you have a time check my simulation khalid.
May Allah SWT bless you my brother.

Salam,
Rizal

[d'First]

Dear Pak Rizal,

Attached, Screenshot as your problems. I think you should review the mass flowrate.

[link Point to another website Only the registered members can access]

[link Point to another website Only the registered members can access]
Best Regards.
Widhi Saputra.
Plant/Process Engineer.
Jakarta, Indonesia.

[d'First]

Dear Pak Rizal,

Attached, Screenshot as your problems. I think you should review the mass flowrate.

[link Point to another website Only the registered members can access]

[link Point to another website Only the registered members can access]
Best Regards.
Widhi Saputra.
Plant/Process Engineer.
Jakarta, Indonesia.