Steam using in a condensate distillation.

[famnghia]

Dear colleagues,

I have a question about steam using in a condensate distillation column.

In this column, they designed a steam stream to the bottom of this column when the feed using for this column is very light. So, why do they design a steam stream go to the bottom of the condensate distillation column?

Otherwise, 2 strippers used steam stream for stripping light components. The result is water mixed to the diesel product. So, is it suitable for this design?

I hope that some of you can help me to explain these questions. Many thanks for your support.

Regards,

famnghia

 

[Homayun]

I think the objective here is to avoid light components entering the downstream system, either a tower or a tank, or maybe a reactor, I don'nt know.
Using direct steam contact is one way of bringing heat into the system, without the risk of cracking the material. I think if you don't use steam, and simply try to get rid of the light material all in a conventional reboiler, that you might get some cracking reaction going on in the reboiler. So I suspect that's why they use steam.

For your other quesiton, namely formation of water, I guess that shouldn't be a problem. water can be easily seprated in the overhead and sent to Waste Water Treatment unit or Souer water treament unit.

 

[Japher]

Could be just for start-up purposes.

 

[25362]

When the dryness of the product diesel is a basic criterion, a bottom reboiled stabilizer to free it from light ends is used.

 

[ajs1972]

Maybe the vacuum in the column is not enough and some steam condenses in the diesel product.