RefinerLink

“A man who pays his bills on time is soon forgotten” -- Oscar Wilde (Irish Poet, Novelist, Dramatist and Critic, 1854-1900)

Refinerlink (www.refinerlink.com) bills itself as an "Oil Refiner Knowledge Portal." It is worth bookmarking.  It is a useful source of information on events, jobs, discussions, blogs, and experts.

Here is an excerpt from a recent articles published on RefinerLink ...

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Truly Optimize FCC Gasoline Distillation
By Optimization Specialist Robert (Nov 11, 2013)
This article uses FCC gasoline property optimization to discuss a complex issue, and how to leverage cross-functional team-work to tackle the problem.
Light Cat Naphtha
We will begin our analysis by focusing on the Light Cat Naphtha stream.  How many variables do you control related to the LCN stream?  If you are a process engineer worth your salt, you will say at least half a dozen for this one stream alone!
If this response surprises you, let’s work through my series of questions above to frame the analysis.
1. What is the value of the molecules in the stream above?
A sub-optimal cut between Olefins and LCN will either leave too many olefins in the LCN stream, or not enough.  The value of olefin stream above the LCN will be governed by downstream unit capabilities, as well as market conditions.  Is there an alky unit downstream of the FCC, and if so, does the Alky have capacity to take more feed?
Also, consider the type of Alky downstream of the FCC.  If your refinery has a Sulfuric Alky, you have greater ability to cut deeper in the olefin draw to capture C5= olefins.  If your refinery has a HF Alky, olefin recovery will be limited by acid strength concerns.
As for market conditions, you should next consider if it is summer or winter.  During the summer time, Alkylation economics strength as isobutane prices deflate and the value of octane strengthens.
2. What is the value of the molecules in the stream below?
Below the LCN stream is HCN.  When gasoline prices are above that of distillate prices, some refiners may be indifferent to the LCN/HCN cutpoint distillation as both streams end up in gasoline product.  When distillate prices are above that of gasoline, most refiners try to minimize the LCN endpoint to maximize distillate production.
source: http://www.refinerlink.com/blog/Truly_Optimize_FCC_Gasoline_Distillation/
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Another site worth bookmarking is the Desulfurization Blog (www.desulf.blogspot.com) ... just another of my time-saver hints.