6 replies to this topic

[Aylool]

Can anyone explain breifly the mechanism of how a deethanizer unit works?

[Zauberberg]

De-C2 tower follows the same design and operational principles as any other distillation column. The only difference is the material selection concept, since the tower is exposed to cryogenic temperatures well below those for which Carbon Steel is rated.

Any textbook is good for start, plenty of information available on the internet as well. See the section #2 at: http://kolmetz.com/pdf/DeMethRev48.pdf

[ankur2061]

For a dethanizer unit in refining unit which requires removal of light ends for LPG production have a look at the following attachment.

Regards,
Ankur.

Attached Files

•  de-ethanizer.pdf   76.31KB   699 downloads

[Padmakar Katre]

Can anyone explain breifly the mechanism of how a deethanizer unit works?

Dear,
The word 'De-ethanizer' stands for the recovery of the ethane from the available feed. The unit configurations would be different in specific applications. The ethane from natural gas is recovered in NGL fraction unit in a LNG train i.e. the demethanizer column bottoms mainly C2+ and very less in C1 are fed to NGL fractionation train where you separate the these liquids. This is the typical recovery under the cryogenic temperatures. Even in LNG you find the substantial quantity of the Ethane. Few years back I was just going through a conceptualization study report by licensor when I was in Algeria for ethane extraction from LNG.(Keep in mind the ethane extraction from LNG is different concept than in ethane recovery in NGL fractionation).
Whereas what Ankur has suggested is basically a Naphtha Stabilizer in Crude distillation unit ovhd circuit with a partial condenser, where the C2(-) with little C3/C4 slip is withdrawn as a top vapor product(C2 minus concentration is very less in un-stabilized naphtha feed) and the distillate is the LPG(C3/C4) and bottoms is the stabilized Naphtha. Apart from this ethane is recovered in Units likes gas plants downstream of FCCU and Delayed cokers or even in an aromatic complex. Hope it helps you.

Attached Files

•  Improving ethane extraction.pdf   190.82KB   353 downloads
•  Improving Ethane recovery and net throughput.pdf   407.61KB   312 downloads
•  Vey high ethane extraction.pdf   506.44KB   292 downloads

[simon_hayton]

The ethane from natural gas is recovered in NGL fraction unit in a LNG train i.e. the demethanizer column bottoms mainly C2+ and very less in C1 are fed to NGL fractionation train where you separate the these liquids. This is the typical recovery under the cryogenic temperatures. Even in LNG you find the substantial quantity of the Ethane. Few years back I was just going through a conceptualization study report by licensor when I was in Algeria for ethane extraction from LNG.(Keep in mind the ethane extraction from LNG is different concept than in ethane recovery in NGL fractionation).

Hi Padmakar,

I am hoping to get started on designing a de-ethaniser unit for a LNG feed in the near future. Could you recommend any good textbooks, articles or other reading material to get some good background knowledge?

Many thanks,
Simon

[Zauberberg]

Simon,

Check Ortloff's web page on C2+ and C3+ recovery. They have state of the art technology for Ethane and LPG recovery processes, involving turbo-expander as heart of the unit.

http://www.ortloff.com/recovery/

[Apirat Chaitanarit]

thanks