Jump to content



Featured Articles

Check out the latest featured articles.

File Library

Check out the latest downloads available in the File Library.

New Article

Product Viscosity vs. Shear

Featured File

Vertical Tank Selection

New Blog Entry

Low Flow in Pipes- posted in Ankur's blog

1

Steam Consumption In Ethylene Plant

steam crackers steam turbines compressors energy reduction

6 replies to this topic
Share this topic:
| More

#1 panoskagiou

panoskagiou

    Gold Member

  • Members
  • 84 posts

Posted 19 April 2019 - 04:49 PM

In furnaces, very high pressure steam is produced from waste heat. This waste heat is actually is recovered from the convection section. By producing this very high pressure steam, then this steam is used in the cracked gas turbines and then there is steam extraction to lower steam levels, such as MP, LP, etc. MP steam for example is used from the turbines, which drive the compressors in the refrigeration cycle. The refrigeration cycle is used from different condensers in distillation columns. Consequently, why we need to reduce the energy of these columns? If we reduce the energy of these columns, that means condenser or reboiler duties reduction. That means steam reduction, which means less recovery of waste heat? Why to reduce the use of the waste of heat, since it is available?

 

 

Thank you in advance!



#2 PingPong

PingPong

    Gold Member

  • Members
  • 1,300 posts

Posted 20 April 2019 - 05:49 AM

Depending on its actual design, the operating Ethylene Plant will either export or import steam.

 

More steam production therefor requires less steam import, or more steam available for export to other process units in the complex.



#3 panoskagiou

panoskagiou

    Gold Member

  • Members
  • 84 posts

Posted 20 April 2019 - 06:52 AM

Thank you so much Ping! From your answer, I can conclude that it is always good to reduce the steam consumption in the downstream, because that means either we will export more steam or we will reduce the import steam. Also, if you know the amount of import steam is an important value comparing to the steam produced by furnaces?



#4 PingPong

PingPong

    Gold Member

  • Members
  • 1,300 posts

Posted 20 April 2019 - 08:34 AM

I am not sure what exactly you mean, but generating steam from waste heat (convection bank ethylene furnaces) is always cheaper than importing steam produced in a boiler burning fuel somewhere in the complex.



#5 panoskagiou

panoskagiou

    Gold Member

  • Members
  • 84 posts

Posted 20 April 2019 - 09:51 AM

Yeah I know that. But, my question is mostly if it is worthy to reduce the energy required in the downstream. A simple example a cryogenic distillation requires refrigerant for the condenser. That means steam for the turbines, which drives the compressors of refrigeration cycle. And my question is why to reduce this energy if it is available as waste from furnaces. Is it more clear now?



#6 PingPong

PingPong

    Gold Member

  • Members
  • 1,300 posts

Posted 21 April 2019 - 08:58 AM

As I indicated before: saving energy reduces steam import (which is a cost) or increases steam export (which has a value).

 

Licensor of ethylene plants (Linde, Lummus, Technip, et cetera) make a design that minimises the specific energy consumption as that is one of the factors that potential clients evaluate when choosing a licensor for their new plant. The value of export steam, and the cost of import steam are included in that specific energy consumption.



#7 panoskagiou

panoskagiou

    Gold Member

  • Members
  • 84 posts

Posted 21 April 2019 - 02:28 PM

Thanks Ping Pong. It is clear!






Similar Topics