6 replies to this topic

[leon_aurel]

Dear all,

I am a fresh graduate from chemical engineering and currently working in an air separation industries as process engineer.
Right now i am searching for a method or technology to get ultra high purity of air separation products. All that i found up till now is '90 technology which use extra column after 2 main columns of air separation plant.
Are there any new technology that can produce ultra high purity products? Maybe using membrane or something else?
Could anyone give me any reference regarding the technology, a journal, book or maybe patent? (i don't ask for a pirated copy version, just give me the link or the title and i'll look for it myself, )

Thank you in advance

Edited by leon_aurel, 07 March 2012 - 09:00 PM.

[Art Montemayor]

Leon:

Congratulations on your first engineering job. That is exactly how I started my professional career precisely 52 years ago. Therefore, I can relate to what is presently confronting you.

My first comment is a bit of advice: Learn to be specific and concise when communicating with other engineers – especially when presenting queries or questions. You have failed to tell us what it is that YOU define as “ultra high purity”. What is high high purity to one engineer may be poor purity to another engineer. Also, be specific in identifying WHAT gas products you are referring to. Do you mean Oxygen, Nitrogen, and Argon? If so, then name them.

Await your specific reply.

[Satyajit]

Leon,
I fully agree if you can define your question with absolute value, it will be easy to answer correctly.
Guessing for N2 of 99.999% purity, air liquification followed by two stages distillation is so far the best process. The normal O2 in N2 product is about 3 ppm and mostly below 10 ppm mostly used for N2 blanketing of catalyst and chemical plants. Suppliers: Air products,Air Liquide,Linde,Prax-air etc.
Other processes are as following:
1. Ammonia craking followed by combution of H2 and then removal of O2 in Deoxo reactor followed by cooling,separation and drying gives 99.99% N2. Supplier: KTI,MVS New Delhi
2. Separation of N2 from air using PSA ( pressure swing adsorption using CMS carbon molecular sieve) process gives 99.8% purity N2: supplier: Holtec USA,MVS New delhi,PSN India etc. You can optimise the unit to bring down O2 below 50 ppm even.
3. Separation of air by membrane unit gives you 95% purity N2.
Hope this is useful.
(Terima Kasih. )
Kind regards,
Satyajit

Edited by Satyajit, 13 March 2012 - 04:22 PM.

[leon_aurel]

Hi Mr. Montemayor and Mr. Satyajit,
Thank you for responding to my questions.
I am sorry for my failure to mention the specifications.
Here are some specifications i found based on Messer specifications,
1. O2 Scientific grade: 99.999%
Impurities : Ar<5 ppm, H2O<1 ppm, THC<0,5 ppm, N2< 5 ppm, CO2< 1 ppm, CO< 1 ppm
2. O2 Ultra high purity: 99.994%
Impurities : H2O< 2ppm, CO< 1 ppm, THC< 0,5 ppm, N2< 20 ppm, CO2< 1 ppm
3. O2 Electronic grade: 99,99%
Impurities : N2< 50 ppm, H2O< 3 ppm, CO< 1 ppm, THC< 1 ppm, CO2< 1 ppm

What does it needed to produce O2 in this grade? Could 1 plant produce this 3 specification? We already have a Air Separation Plant with 99,999% N2, 99,99% Ar and 99,6% O2 . Could it be retrofitted with new additional columns to make O2 with one of the qualities i stated above or should we make a new whole plant?

I'll be glad for any suggestion or critic regarding my failure

Edited by leon_aurel, 13 March 2012 - 09:29 PM.

[Satyajit]

Leon,
Yes, it is possible to upgrade your plant to get the quality you are looking for. I would recommend you to contact your plant supplier ( Air products, Air Liquide,Prax air ,Linde who ever may be) .
Kind regards,
Satyajit

[leon_aurel]

Dear Mr Satyajit,
I need to know the method get above mentioned O2 purity, maybe you could mention some journals or books, so i can look for it myself.

Best regards

[breizh]

Hi ,
Let you try to find a copy of :

Industrial gas handbook by Frank G Kerry -CRC Press

Breizh