Where is Polynaphtha used?
PolynaphthaTM is one of the indirect alkylation processes upgrading low value C3/C4 cuts from FCC / SC into gasoline and middle distillates by oligomerization of the light olefins contained in the C3/C4 cuts.
Feedstock choices include propylene and mixed-butenes fractions (or combinations) present in C3 and C4 cuts from cracking processes including olefinic C3 and C4 cuts from Fischer-Tropsch process.
Axens’ Polynaphtha technology relies on the following main features:
- Almost complete olefins conversion
- Large and flexible range of product grade slate from 100% gasoline to maximization of distillates
- High RON gasoline fraction
- Jet A1 quality for kerosene downstream of Hydrotreatment
- Environmentally friendly catalyst
- Fully regenerable catalyst
- high mechanical strength allowing multiple regenerations
- No pressure drop issue
- Life span superior to 10 years has been industrially demonstrated
- Easy catalyst loading and unloading without acidic waste
- Moderate operating conditions
- Simple and low cost fixed bed process
Axens has experience of the revamping of competing technology plants into Polynaphtha.
Depending on the nature and the content of contaminants in the feed, pretreatments can be included upstream of the Polynaphtha, such as Axens Alkyfining process for dienes removal or molecular sieves, to extend the oligomerization catalyst cycle.
Where Olefins are a constraint in the gasoline pool, Axens can install, downstream of the Polynaphtha on the gasoline fraction, a dedicated low cost Hydrogenation process to control the olefin saturation to the requested level to meet pool specifications.
When used in conjunction with the FlexEne concept, Polynaphtha can even bring a bonus by increasing Propylene and Distillate production through appropriate recycling and further cracking of gasoline or distillate or both fractions into the FCC riser.
Gasoline and Diesel Imbalances - Part 1
Gasoline and Diesel Imbalances - Part 2