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

Processing Crude With 10 Api


This topic has been archived. This means that you cannot reply to this topic.
9 replies to this topic
Share this topic:
| More

#1 Swetha Mohan

Swetha Mohan

    Junior Member

  • Members
  • 16 posts

Posted 12 February 2015 - 02:40 AM

Dear all, have you come across any refinery processing crude with 10 API crude say blend of crude or single crude like boscan or patoz whose API is around 10. Is it possible to process the crude with 10 API or lower in crude column. 



#2 PingPong

PingPong

    Gold Member

  • Members
  • 1,446 posts

Posted 12 February 2015 - 06:27 AM

Axeon's 30,000 BPSD asphalt refinery (formerly NuStar, formerly Citgo) at Savannah was capable of running on pure Boscan crude. I don't think it is still in operation.

 

You should realise that there is a difference between a refinery that is designed for such crude, and a refinery that is not.

 

When looking at a crude assay, do not only look at it's API gravity, but also at its viscosity, pour point, Sulfur and TAN. And those of the products, such as gasoil, VGO and Residue.

 

Running pure Boscan in an existing CDU that is designed for "normal" crudes will be difficult, if possible at all. Boscan is very viscous so that is a problem for pumps, desalter, exchangers, et cetera. You would need to recycle a lot of gasoil to make the crude feed more manageable. The trays in the existing crude column will weep due to insufficient vapor flow, especially in the top part. Moreover Boscan has a high S content and high TAN so that may be a problem for existing materials.

 

In 2003, when the Savannah asphalt refinery was owned by Citgo, it was revamped as described in the article below:

 

Attached File  Revamp Savannah Georgia Refinery OGJ 7march2005 .pdf   189KB   36 downloads

 

As can be seen the refinery only has an atmospheric crude column, no vacuum column.  The atmospheric residue is the asphalt product.

 

 


Edited by PingPong, 12 February 2015 - 08:27 AM.


#3 Swetha Mohan

Swetha Mohan

    Junior Member

  • Members
  • 16 posts

Posted 12 February 2015 - 08:26 AM

Sir, many thanks for your prompt reply. But is there any other refineries that operate 10-15 API. If none of the refinery process such crude, then any idea what is the lowest API crude a refinery is processing? May be 15 API above??? 



#4 PingPong

PingPong

    Gold Member

  • Members
  • 1,446 posts

Posted 12 February 2015 - 08:39 AM   Best Answer

There are other asphalt refineries that are processing crudes like Boscan. What is the reason for your question?

 

I don't think there is a lower limit on the API that can be processed, as long as the unit is designed for that crude.

Again: properties like viscosity, S and TAN are more important in the design of a new unit, and especially in the operation of an existing unit, than API gravity.

But the economics of processing low API can be so poor that there is no incentiven to process such crude in a CDU.

 

Canadian tarsands are processed in Hydrocrackers like LC-Fining to produce a syncrude that can then be processed in conventional refineries.



#5 gegio1960

gegio1960

    Gold Member

  • Members
  • 517 posts

Posted 13 February 2015 - 12:35 AM

Other than sharing Ping Pong view I can add some considerations from my experience:

- the common approach consists in adding to the heavy crude either a naphtha or a condensate taking care of compatibility isuues. Naphtha is recovered and recycled

- in specific cases a vacuum flashing unit is used to remove the gasoil fraction from the bitumen

- several mediterranean refineries have processed in their CDUs the "topped" crudes coming from Libyan refineries and residual fuel oils coming from Russia

I remember at least 3 projects of that kind...moreover I'd consider the option to treat the extra-heavy crude directly in a Deasphalting unit (just an idea, no direct experience).



#6 Swetha Mohan

Swetha Mohan

    Junior Member

  • Members
  • 16 posts

Posted 16 February 2015 - 04:30 AM

Dear Sir, any idea about Savannah has run the operation with 100% boscan crude or boscan is blended with some other crudes to make a crude blend??



#7 PingPong

PingPong

    Gold Member

  • Members
  • 1,446 posts

Posted 16 February 2015 - 07:26 AM

Yes, Savannah has run pure Boscan. Is also stated in the OGJ article above on the 2003 revamp.

 

And in an old NuStar powerpoint:

 

Attached File  Savannah Georgia Asphalt Refinery.jpg   150.1KB   3 downloads



#8 Swetha Mohan

Swetha Mohan

    Junior Member

  • Members
  • 16 posts

Posted 17 February 2015 - 05:03 AM

Thank You, so much. It's very useful.



#9 Swetha Mohan

Swetha Mohan

    Junior Member

  • Members
  • 16 posts

Posted 17 February 2015 - 06:38 AM

Dear Ping Pong & Gegio 1960, both of yours comments and inputs are really informative. Do you or anybody in the group has idea whether Savanna Refinery is in operation because in one article it was mentioned that the Savannah Refinery has been idle since 2012. So is it running or under shutdown?

 

Our Refinery is still under designing stage. So the column could be designed based on the metallurgy requirement for high TAN/sulfur and other properties. But if any refinery might have got problem while processing low API crude say 10-12 API, I would like to know the problems which they have faced. SO that we can reconsider the selection of crude or rectify/do necessary arrangements to overcome the operational problems.



#10 PingPong

PingPong

    Gold Member

  • Members
  • 1,446 posts

Posted 17 February 2015 - 02:02 PM

It seems that the CDU at Savannah is no longer operated, but the storage and other facilities are still used as a terminal.

 

Savannay unit has been operating for decades, so I don't think that Boscan is the problem. The CDU is/was only 30.000 BPSD so it may not be economical anymore to operate and maintain that old unit.

You could contact Axeon if you like to know for sure.

 

Axeon also operates a larger refinery at Paulsboro, operating two parallel CDU's, one designed for pure Boscan and one for pure BCF-13 (Bachaquero). But nowadays they also import heavy oil from Canadia.






Similar Topics