Axens oligomerization technologies rely on strong expertise accumulated over 50 years in order to provide the most appropriate solutions to achieve high conversions of light olefinic fractions into higher value gasoline and middle distillates in association with dedicated catalysts specially developed for these applications:
- TA 801 is a resin type catalyst devoted to the OATSTM process
- IP 811 which is proposed in the applications is characterized by the following main features:
- High activity
- Selective adjustments towards gasoline or middle distillate fractions depending on the severity of the operation
- Fully regenerable catalyst and high mechanical strength allowing multiple regenerations. Life span superior to 10 years has been industrially demonstrated
Axens can offer a large range of simple, robust and flexible processes to address the market demand:
The OATS process constitutes a low cost alternative using a TA 801 resin type catalyst. This process, which was originally developed to desulfurize the light fraction of the FCC gasoline, can be tuned to favor oligomerization reactions on the light cracked naphtha recovered downstream of Prime-G+ first step process. You are then able to switch part of the gasoline towards distillate fractions, thus addressing the increasing demand for distillates.
The SelectopolTM is a low severity process using IP 811 catalyst with the objective to selectively convert isobutene of an olefinic C4 fraction to high octane, low RVP gasoline blending stock. Enriched n-butenes raffinate can ideally be used for Petrochemicals application such as feed for methathesis or Methyl ethyl Ketone plants. The technology provides a low cost way of retrofitting existing etherification units.
The PolynaphthaTM process achieves high conversions of light olefinic LPG fractions into higher value car fuels (mixed gasoline and middle distillate product) giving the refiner a wide choice of feedstocks and product distributions. Oligomer Products can be used as high octane blending stocks for the gasoline pool and high smoke point blending stocks for kerosene, jet fuel or the diesel pool. Polynaphtha uses the same IP 811 catalyst as Selectopol operates at higher severity. It is designed to synchronize the FCC turnaround. The Polynaphtha technology is well suited for revamping existing phosphoric acid polymerization units. Further propylene, gasoline or distillate enhancement can be attained in association with the Flexene concept.
PolyFuel® is an innovative technology which aimed at maximizing the middle distillates production by converting light olefins from gasoline into distillate at minimum cost. PolyFuel process takes benefit of the use of IP 811 catalyst initially developed for Polynaphtha and Selectopol. Thanks to its high activity and stability, IP 811 can be operated at high severity to maximize middle distillate fraction. The implementation of the first Prime-G+TM selective hydrogenation step on the full range FCC gasoline is an ideal feed pretreatment to lower the diolefins and sulfur content of the light C5-C6 feed to PolyFuel thus permitting to maximize IP 811 catalyst cycle. A continuous operation is possible through permutable reactors. Used within the FlexEne concept flexibility towards Propylene maximization can be also targeted.
FlexEne™ is an innovative combination of two well-proven technologies: Fluidized catalytic cracking (FCC) and Oligomerization (Polynaphtha/PolyFuel) in which highly reactive oligomers can be selectively cracked towards propylene and lighter olefins in the FCC, without any reactor modification. As this makes more feed to the oligomerization unit, the process can significantly improve product flexibility toward propylene gasoline or middle distillates according to the market demand. FlexEne can be easily applied to existing refinery configurations or in grassroots projects with a low additional investment relative to the FCC complex.