5 replies to this topic

[bapo]

Hello all i'm new to this site. i am a third year chemical engineer at curtin university in perth australia. For one of my assignments we have been told to find a process flow diagram or preferably overall P&ID for ethylene production. I've searched all over the net and in the library here but haven't been able to find any. If anyone can point me in the right direction to find one with a bit of info on it that would be really helpful.
Any help appreciated
Bapo

[Art Montemayor]

bapo:

If someone (especially an instructor) told you to go find a P&ID for the production of ethylene, he/she is not leveling with you and sending you off on a wild goose chase.

Even if you return with a real P&ID to the classroom, the chances are that it is not a legal copy or that it has been stolen. No engineering company or contractor is going to allow their P&ID to be distributed to the public - especially through the InterNet. That's the fastest and easiest way to give away all the technology that you worked and sweated to accomplish.

If you were really asked to do that, you have been asked to do something that is very close to being un-ethical --- and that's not teaching engineering. That's teaching pirating technology.

What a chemical engineering instructor is supposed to teach you is how to GENERATE a P&ID yourself, not take it from someone else.

I seriously doubt if you are going to succeed in this quest for some else's hard work product.

[gvdlans]

In addition to Art's post, I would like to remark that there is no such thing as an "overall P&ID for ethylene production". A complete Ethylene plant (even the simple ones, e.g. that crack only ethane) will consist of many P&IDs. I would say at least 30 for the main process only. You would also have at least 10 process flow diagrams (or one that is very wide....)

My guess is that what you are looking for is an "overall block flow diagram", such as that is shown here: http://www.cbi.com/l...fs/ethylene.pdf

I can also recommend the book "Ethylene, Keystone to the Petrochemical Industry" by Ludwig Kniel. It can be bought via Amazon, or maybe you can find a copy in your library. It contains PFD type diagrams of the process.

Maybe your instructor doesn't know what a P&ID really is?

[mishra.anand72@gmail.com]

Either you go back to instructor reporting that you could not find PFD/PID as instructed or mail me. May be I will be help you remaining within the framework of knowlegde found in books. So you will obtain PFD that will be rough sketch of real process.

Pick up your options. Your time starts now.

[bapo]

Hello i've e-mailed my tutor a summary of all your responces. We are just learning P&ID's so i doubt we are expected to develop out own. i would imagine that they did mean a block flow or even PFD all your help is greatly appreciated.

[Padmakar Katre]

Dear,
Before making the P&ID of any process the first make sure that you have thorough knowledge of the respected process. Here I am replying in general and not inthe context of what you want i.e. ready P&ID of the ethylene plant. Just follow some of the points which will help you to prepare the P&ID by yourself which may or may not be competitive to the industrial one but for academics purpose I hope it will solve your problem.
1. First know the process thorough.
2. Prepare the block diagram of the entire process.
3. Prepare the PFD from your block diagram.
4. Now read the process instrumentation and control books as well the piping handbooks books which you will find in your library. Which will guide you for the basic symbols which are used to prepare the P&ID.
5. Select the key parameters to be controlled like temperature, pressure, level, flow and all. Check for the best control system option like ratio controller/cascade/split-range control and so many. And finally configure thses controllers in your P&ID.
I am not sure that in third year of engineering you would be aware about the trips and interlock system if you are its good. Provide the necessary trips and interlocks in your P&ID.
The best way to get rid of these issues is to visit the plant or any enginering consultancy by asking your college management to arrange it for your class students (I am sure your college will have an knowledge exchange programms with the organizations like manufacturing units ) and you can see the P&IDs there which you can do so that you will get a feel how P&IDs are. And you can discuss with the process engineers there who will help you to understand the subject in a well manner as I don't expect from your teacher who asked you to get the P&IDs from internet, his instructions itself creats doubt regarding his awareness about the subject (I am sorry if I am making any harsh statement). Once you will start preparing the P&IDs please come and ask your qureies here in the forum I hope you will get good replies to your problems.
All the best.