5 replies to this topic

[Art Montemayor]

Yes, I fully agree. This subject is far too broad and general to be addressed in a positive and gainful manner.

However, I consider this question very practical, important, insightful, and thoroughly appropriate for engineering students or recent graduates. Contrary to your feeling, I consider this question to be more in line with deep and professional interest instead of mere curiosity. I also consider this question to represent the demarcation in the life of a young engineer who must be “weaned” and cease to be nurtured solely by theoretical works and enter the realm of real-life technology – which defines the engineering career.

I consider this to be a very important step in the life of all engineers. We, the older set, have all had to go through this portal – sometimes pushed, sometimes prodded – but we’ve all had to accept that reality is far from what we were taught at the university level. But that’s OK and very normal. Universities are not charged with introducing us to real life; they are responsible for teaching us how to learn to be engineers – not to convert us into engineers.

I know that a lot of my experienced colleagues on this forum would welcome the opportunity to share with you much of our experience and factual information on what-and-how to startup, operate and shutdown a distillation train SAFELY. However, this forum is not a seminar – nor is it suited for one. What I recommend you (or others like you) do is to write us the specifics on a given situation or challenge. For example, tell us the scope of your objective, the equipment in question (fully described), the fluids, the utilities, the controls involved, and any additional pertinent data you can offer. The more information you furnish, the better and more explicit the response will be. Supply a sketch P&ID if you can; this will help greatly. Tell us your concerns and doubts and be specific in your detailed questions so we can go directly to the source of your concern. Do not submit general questions like: “How do I operate an Acetone-water distillation?”. If you have concerns about a certain startup, state and describe that. If you have concerns about a certain upset of a distillation column, state those concerns. If you don’t know what concerns you should have during a certain distillation, state that fact and ask what you should be considering as potential problems regarding a specific distillation.

I hope I’ve succeeded in specifying how to approach this type of queries. Do not try to combine a lot of different concerns in the same thread. This can really get out of hand and result in mass confusion. Divide and conquer. It may take more threads for all concerns, but the answers will be readable, understandable, and organized.

I hope my suggestions find your approval and others will also concur. If not, please feel free to suggest another or other methods of attack. We’ll await your reply(ies).

Art

[mbeychok]

Guest_guest:

If you are currently working for a company that operates a plant with distillation columns, one of the best things you could do would be to get together with the plant operators and ask them to share their knowledge with you. It has been my experience that the plant operators have a world of knowledge to share, if you befriend them. Don't make the mistake of thinking that their lack of a college education means that they are somehow inferior to you! In many cases, they know more about their plant than the headquarters' engineers do.

[gvdlans]

Following book may be useful:

"Distillation Operation" by Henry Z. Kister. Other than in his other book "Distillation Design", this book focusses on column troubleshooting, commissioning, start-up and operations. It can for example be bought via Amazon.com

[tlp]

Hello! all

Thanks very much Art, mbeychok and Gvdlans for your kind reply and suggestions.

Art, I agree with you that we can divide this subject into series of topics and discuss, which would bring in more clarity. I'll take a process known to me as an example and generilize it to the extent possible to maintain the company secrecy and then come up with more specific practical questions.

mbeychok, I agree and believe like you that the operators are the best people from whom we can gain the practical knowledge. But, unfortunately I work miles away from the plants, which makes it very difficult for me to visit and also, to interact with the plant people. Thanks again for your suggestion.

gvdlans, Thanks very much for suggesting the book, I've heard it from few other people also that the book is good, Somebody has barrowed the book from our library, I would definitely read the book once I get the copy.

I'll come up with more specific questions, meanwhile other forum members can contribute to this subject with specific questions or with suggestions to take this subject forward.

Regards
tlp

[Art Montemayor]

Tip:

Since you seem to be deeply interested, I suggest you do the following in order to obtain some background on the general subject of "Distillation":

1) Buy or own the book "Distillation Control" by Greg Shinskey; McGraw-Hill Book Co.(1984). This is a classic by a super-great teacher in the world of process controls. Read it, and go back and read it again. It should be a pre-requisite for all up-coming new graduates. You'll need to dominate its contents in order to follow up and understand the experiences and recommendations you will receive from experts (many of them actual unit operators within the plants) in the field.

2) Go to: http://www.driedger.ca/#intro
Download and avidly study all six papers authored by Walt Driedger:

a) Controlling Centrifugal pumps;
b) Controlling Reciprocating pumps;
c) Controlling Shell & Tube Heat Exchangers;
d) Controlling Steam Heaters;
e) Controlling Fired Heaters;
f) Controlling Vessels and Tanks.

You'll find Walt's papers full of detailed and experienced know-how on controlling a lot of the vital peripheral or auxillary equipment associated with a normal distillation unit.

Distillation is about basic Chemical Engineering heat and mass transfer PLUS a lot of process control. The answers to a lot of your concerns and questions will revert back to this basic knowledge and expertise.

I hope this helps prepare and orients you for what's ahead. Good reading!

Art