Axens to supply technologies for S-OIL’s residue upgrading capacity expansion project

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Axens has been awarded several contracts for the expansion of the existing residue conversion facilities at S-Oil’s Onsan refinery in South Korea.

The Residue Upgrading Complex Project (RUCP) is aimed at reducing fuel oil production while producing propylene through the conversion of atmospheric residue and will include the world’s first commercial High Severity FCC unit (HS-FCC™).

For this complex (RUCP), Axens has supplied the following technologies:

  • An Atmospheric residue desulfurization unit (Hyvahl™)–for the production of diesel and improvement of residue quality. Hyvahl unit includes a Permutable Reactor System (PRS);
  • A High Severity FCC unit (HS-FCC™)–for the conversion of the hydrotreated residue produced by the Hyvahl unit. The HS-FCC technology bridges the refining and petrochemical gap by maximizing propylene production using an innovative down flow reactor;
  • An unsaturated liquefied petroleum gas (LPG) extractive sweetening unit (Sulfrex™)–for the treatment of the LPG cut originating from the HS-FCC unit upstream of polymer-grade propylene recovery process (PRU).

Axens will provide technology licenses, basic engineering, catalysts, adsorbents and proprietary equipment for the complex.

In addition, Axens has supplied the following technologies:

  • A selective desulfurization unit (Prime-G+™) for the treatment of the HS-FCC gasoline;
  • A C4-stream processing section including a C4 selective hydrogenation unit, a MTBE unit, a super-fractionator and a butane isomerization unit.  This section will produce MTBE and 1-butene which will be used as a co-monomer in polymerization applications, as well as isobutane feed for an alkylation unit.

The RUCP scheme is the result of a conceptual study carried out by Axens’ Performance Programs business unit which provides services for new and existing plants in the refining and petrochemical industries.

HS-FCC is an advanced technology, developed by the alliance comprised of Saudi Aramco, JX Nippon Oil & Energy Corp. (JX), King Fahd University of Petroleum and Minerals (KFUPM), and which is licensed by Axens and Technip Stone & Webster. The technology produces higher yields of propylene and other light valuable products than conventional fluidized catalytic cracking units.

PRS is part of the Hyvahl unit and protects the downstream catalysts by removing or converting a sizeable portion of sediment, metals and asphaltenes from the feed.


S-Oil, www.s-oil.comS-OIL, established in 1976, has grown into one of the most competitive oil refiners in the Asia-Pacific region by establishing profitability-oriented management strategies and nurturing a dynamic and progressive spirit in its management. The company operates the oil refinery facility with a capacity of 580,000barrels per day (BPD), and other facilities that can produce petrochemicals and lube base oil in the Onsan Refinery in Ulsan. S-OIL is strengthening its status as a leader in protecting customers and the environment by producing and supplying the best quality oil products based on the world-class Bunker-C Cracking Center (BCC) and the Xylene Center, a PX plant with the world’s highest production capacity for a single facility.


Axens,, an IFP Group affiliate, is an international provider of advanced technologies, catalysts, adsorbents and services, with a global reputation for basic engineering design excellence. The main scope of Axens' business is focused on the conversion of oil, coal, natural gas and biomass to clean fuels as well as production and purification of major petrochemical intermediates. Axens’ global offer is based on: highly trained human resources, modern production facilities and extensive commercial feedback from plants using our processes and catalysts all around the world.