9 replies to this topic

[trungphu]

Hello everyone,

 

 Have you ever see a distillation column with two reboilers inside, one in the bottom of the column and one in the middle of column. I dont know how to design this column. Could someone share me some ideas?

 

Thanks in advance

 

[thorium90]

I have never seen such a column either, but perhaps you can share why is there a need for an extra reboiler in the middle of the column? I understand the purpose of side strippers and pumparounds etc, but a reboiler in the middle is something new to me too.

[Art Montemayor]

Trungphu:

 

There's no explaining if anyone has seen a reboiler feeding the middle section of a distillation column (you have not said if it is the rectification section or the stripping section).  What difference would that make in explaining to you why it is there?

 

The important thing is for you to explain YOUR need for such a column and WHY.  This is easily done by submitting your calculations and a McCabe-Thiele or Ponchon-Savarit Diagram showing the exact, theoretical location of the intermediate reboil vapor.  That should explain to everyone why the reboiler vapor is needed there.  Calculating the Process capacity and mechanical design should not be a problem.  The problem is justifying its need and location.

[Dedi]

Mr. Trungphu

 

i've never seen distillation column with two reboiler in any problems of my college life, can you explain it why there is need a reboiler in middle of column so it can expand my knowledge in distillation.

thanks for your consideration and hope you found your answer 

[thorium90]

Ahh, I think I get what you are hinting at; multiple shells. But that doesnt explain why the 2nd one is in the middle.

[Padmakar Katre]

Hi Trungphu,

Could you please further elaborate the system with some additonal info such as sketch of the column with two exchangers connection. A brief description of the process or objective of system can help readers to share their thoughts which may help you in understanding.

[trungphu]

Thank you so much for all your advices and considerations.

 

The aim  of placing a reboiler in the middle of column that I found in a document is to reduce the heat transfer area of the bottom reboiler.

A brief description of the process can be found in this paper : SHELL SULFOLANE PROCESS UNIT (EXTRACTIVE  DISTILLATON).

[trungphu]

This is a part of SHELL SULFOLANE PROCESS UNIT paper.

[Art Montemayor]

Trungphu:

 

You initially wrote: “Have you ever see a distillation column with two reboilers inside, one in the bottom of the column and one in the middle of column.  I don’t know how to design this column.  Could someone share me some ideas?”

 

I responded: “Calculating the Process capacity and mechanical design should not be a problem.  The problem is justifying its need and location.”

 

Now I discover that you have known of the reason and had a detailed explanation for the need and the location for the two reboilers.  You knew this because you have a confidential UOP document that you have scanned and inserted into this thread that clearly states: “This information is confidential.  Do not disclose it to others, copy it, or use it for any purpose unless you have UOP’S permission.”  Clearly, this is a confidential document that details out UOP's Sulfolane Process.  How you obtained it is only a guess; but it is confidential, intellectual property that belongs legally to UOP and only UOP can decide to publish it or distribute it to others.

 

I have deleted all the above information that you submitted in this thread because it clearly is intellectual property and our Forums cannot condone this unethical and illegal practice.  I don’t know how engineering is being taught in Vietnam at present, but surely you are aware that moral, ethical, and legal rules and laws exist in engineering just as elsewhere.  If you have UOP’s permission to show us this information, then I stand corrected.  However, I seriously doubt that.

 

From the above, it is obvious that you already knew the answer to this private, intellectual property and nevertheless asked for the obvious answer – which I furnished.  I don’t represent UOP (nor do I wish to) but if I am to maintain myself as serious and trustworthy engineer when I work on projects, I must live and abide by the ethical and moral standards that govern my profession.  Otherwise, no one will trust me with their information and employment and I would find myself out in the street, without employment or anyone to trust me.  If you can’t be trusted, you will never be employed.  I highly recommend that you follow this principle and not obtain, copy, reveal, nor traffic in confidential engineering information. 

[trungphu]

Mr Montemayor:

 

Actually, this is the first time I see such a column. I just wanted to share this interesting column and refer others' idea. I didn't mean to break the law. Now, I know I was wrong. I really sorry about that.