Process Technologies

Selectopropane

The residue from spent oil Rerefining is sent to the optional Selectopropane unit if recovery of brightstock and asphalt are desired.

Revivoil™

Revivoil™ is Axens Solutions' optimum route to lube bases from spent oil. This process, developed jointly by Axens and Itelyum (formerly Viscolube Italiana SpA), goes far to put spent oil rerefining on the fast track to success. Apart from the usual problem of collecting spent oil, traditional spent oil processing has been an underachiever when it comes to quality, yields, ecology and economics.

Safe, simple and environmentally friendly, Revivoil™ technology has the ability to re-process spent oils for the production of various grade of base oils ready to market.

Wax Hydrotreating

The merits of Axens’ process for wax hydrotreating are as follows:

• No sludge disposal problems
• Easy and reliable operation
• Great flexibility of use
• Low operating cost
• High yield: around 99 wt% for all types of products assuming that the correct type of catalyst has been selected.

Most severe food specifications reached even for microcrystalline waxes.

White Oils Hydrotreating

When the objective is technical-grade white oils, a one-step process is required, that uses a catalyst and a configuration close to that of hydrofinishing for motor base oil production.

When the objective is medicinal-grade white oils, a second step is necessary after that required for technical-grade products, in particular to completely eliminate polycyclic aromatics. In all cases, those white oils comply with BGA, FDA and CODEX quality specifications.

HyDeWAX™

HyDeWax™ is a two-stage process.

During the initial stage the cold flow properties of the UCO (unconverted oil) produced in the hydrocracking reactor or the hydrorefined VGO are improved through hydro-isomerization reactions of the n paraffins. The n-paraffins have poor cold flow properties, the hydro-isomerization step improves the lube base oil cold flow properties considerably while reaching higher yields than with a conventional solvent process scheme. During the hydro-finishing stage, aromatic molecules are saturated and the color and stability of the oil are brought to specification.

HyDeWax™ can also upgrade 100% wax feed in order to produce high quality lubes.

Lube Hydrofinishing

The target of Axens Hydrofinishing process is to adjust color and stability requirement for motor base oils. In that purpose, polar compounds (oxygenate, unsaturated, ...), responsible for both brown color in lubes and instability, are hydrogenated.

This process uses classical desulfurization catalysts in low severity operating conditions (low temperature and low hydrogen partial pressure).

Lube Oil Hydrorefining

The hydrorefining/hydrocracking scheme for lube base oil manufacturing has many advantages over the conventional solvent process scheme:

• Higher flexibility
• Higher yields of high-value, high-quality lube base oils
• Higher viscosity index: between 95 and 145
• Production of high-quality fractions: gasoline, jet and diesel fuel
• No wax production

HyK™

HyK™ is Axens high conversion Hydrocracking technology that converts middle distillates or heavy distillates into more valuable products. Apart from the conventional Straight Run VGO, other feeds that could be processed in a hydrocracker includes:

• Heavy Coker Gasoil (HCGO) produced from Delayed coker or Flexicoking process,
• Deasphalted oil (DAO) from SDA,
• VGO cut produced from Resid hydrocracker (ebullated bed or slurry technology),
• Straight run kerosene and diesel,
• LCO coming from FCC,
• LCGO from coker.

In order to adjust the product yields and meet the most profitable production targets it is necessary to choose the right process scheme for each project:

• “Once-Through scheme” offers the possibility to produce middle distillates and valorize the VGO feeds as top-quality Group III lubes or petchem feedstock,
• “Single Stage with Recycle scheme” boosts the conversion and selectivity towards valuable fuels with moderate increase of the investment cost,
• “Two-Stage scheme” offers the best selectivity towards high-value middle distillates or naphtha for petchem while minimizing the unconverted bleed.

Prime-D™ with cracking

While having to handle heavier diesel cuts, the refiner has to address the demand for more gasoline for the fuel market or for petrochemicals production downstream.

Consequently, the middle distillates hydrotreatment target is evolving to bring sufficient flexibility to the products properties as well as yields adjustment. To this end, deep optimization of cracking and hydrotreatment catalyst systems are required.

Prime-D™ with cracking is the optimal solution when deep hydrogenation is not enough to reach stringent specifications on density and/or cetane for refractory feedstocks, or when additional gasoline production is desired.

Prime-D™ with dewaxing

In addition to reaching ultra-low sulfur content, cold flow properties and specifications of the diesel product may have to be improved due to local climatic constraints.

Prime-D™ with dewaxing is a competitive alternative for cold flow properties improvement as compared to more costly options such as feed undercutting, kerosene blending, or chemical additive addition, leading to high operating costs and loss in diesel yield.