Q & A > Question Details
What is the best way to theoretically blend isomerate and reformate for octane number from gc data linear blending vs index blending using blending octane number Further what is the source of obtaining blending octane number of individual hydrocarbon
22/02/2020 A: keith bowers, B and B Consulting, kebowers47@gmail.com
There is no single answer for such a 'general' question. The 'best' method depends on the composition ranges of the blending components and the concentration ranges in the blend. IF components have a narrow range of composition and pure Octanes, one can easily construct a matrix of 'test blends' and run engine octanes and determine the 'blending octane index' of the two streams vs stream composition and blend composition.
The 'engine octanes' of 'reformate' streams are technically 'performance numbers' as they may be well over 100 and the 'reference fuels' are blends of iso-octane and TEL.

The engine measured knock intensity is exquisitely sensitive to test engine condition, engine intake air temperature, humidity,and any trace hydrocarbon contamination in the intake air--- and the TEL addition precision. Precision of these 'performance numbers' is not nearly as good as for Isomerates or other fuels below 100 (pure iso-octane.)

Since each refinery has unique operations and differing reformate and isomerates. a test blend matrix and blending number study is usually the best solution.
30/01/2020 A: Sridhar Balakrishnan, Bharat Oman Refineries Limited , laksrid@yahoo.com
The best sources could be petroleum engineering books ,API handbook , Nelson petroleum engg. handbook etc.
22/01/2020 A: Joel Kaye, Retired from UOP & Tesoro, kaye13@gmail.com
To accurately predict the blended octane you will need to adjust with either blend index or blend octane numbers for the components. There is publicly available information on different methods. However, accurate octane from GC alone is difficult, you may need to run engine octanes along with your GC prediction and use a correction factor on your projection.