Incompatibility of Crude oil during blending 1

[Petro0707]

Hi...Everybody....Warm good morning to all of you..!!

Currently we process diffrent type of crude oils by blending and depending on the Refinery Economics benefits,we blend diffrent type of crude oils like Maya,Arab light ,Arab heavy etc.I have heard that certain crude oil should not blended in the crudemix basket with other type of crude oils especially while processing lower API Crudemix blending like 24° API crudemix.
I request you to all of you that is there any specific compatibility matrix for crude oil blending ?

Thanks in advance...!!!

 

[25362]

I hope you find useful info in:

http://www.solublesolutions.com

http://www.aiche-chicago.org/symposium06/wiehe.pdf

 

[0707]

“Crude oils with low carbon, high hydrogen, and high API gravity are usually rich in paraffin and tend to yield greater proportions of gasoline and light petroleum products; those with high carbon, low hydrogen, and low API gravities are usually rich in aromatics.
Oil refineries are designed to refine specific types of crude oils. A refinery designed to refine light sweet crude would not be able to efficiently refine a heavy crude, if at all. The heavy crude does not require as severe processing as do the light crude.

Sweet and sour crude are so defined based on the percentage of sulphur contained in the crude. The breaking point between sweet and sour crude is not well defined, but generally less than 2 weight percent is considered to be sweet, while greater than 2 weight percent is considered to be sour. The majority of the sulphur in the crude remains in the highest boiling point fraction or the bottom residuum, the asphalt. Since light sweet crude might yield only 15% asphalt, and heavy sour crude might yield 50% asphalt, the asphalt from the light sweet crude may actually contain a larger percentage of sulphur.

Heavy and light crude are so defined based on the API gravity or specific gravity of the crude. The API gravity and specific gravity are related by the following equation, S.G.=(141.5)/(131.5+API) where the higher the API, the lower the S.G. High API gravities are indicative of light crude, while low API gravities are indicative of heavy crude. The breaking point between heavy and light crude is not well defined, but generally API gravity less than 25 is considered to be heavy, while API gravity greater than 25 is considered to be light.

When crude oils are blended in the wrong proportions or even the wrong order, they can precipitate asphaltenes (called incompatibility). Once precipitated, it is difficult to redissolve asphaltenes quickly. Meanwhile, precipitated asphaltenes can cause stable oil-water emulsions, fouling of heat exchangers, and catastrophic coking of distillation furnace tubes”

On asphaltene subject go to

http://www.solublesolutions.com/Near_Inc.doc

cheers

Luis marques