Other Technologies

EXOS™ Technology Description

ExoS™ is our exclusive sulfur extraction technology for mid-cut FCC naphtha. Proven in multiple successful field installations, ExoS is a simple process of extraction and distillation steps with no specialized equipment or hydrogen required. Generating an olefin-rich C6-C7 raffinate with less than 10 ppm Sulfur that bypasses the hydrotreater, ExoS is the environmentally friendly, low-waste generating method for meeting clean-fuel sulfur limits.

ExoS can be installed with a new hydrotreater to reduce the size, CAPEX and OPEX of the hydrotreater. It can also be installed as a revamp to save octane and free up hydrotreater capacity. With ExoS technology, you can utilize the olefin-rich raffinate stream directly in the gasoline blending pool or as feed to other processes.


ExoS FCC Diagram

ExoS Process Diagram

Key Features

The ExoS™ process technology offers the following advantages:

  • Reduced total FCC naphtha pool octane loss of <1 vs 2-4+ for conventional hydrotreating
  • Decreased hydrotreater feed flow by up to 40% and H2 consumption by up to 50%
  • Reduced size, CAPEX and OPEX of the hydrotreater
  • Elimination or reduction of light FCC naphtha treatment (unit can accept C5s also)
  • Ability to use the low-sulfur, olefin-rich raffinate stream directly in the gasoline blending pool or as feed to other processes
  • Reduced energy consumption compared to the competitors’ extractive distillation process due to our multi-step liquid/liquid extraction and distillation process


INVISTA offers a comprehensive technology transfer package and proprietary solvent for the ExoS™ process technology. INVISTA and its partners at Koch Engineered Solutions are open to expanded execution scope (EP, EPC, LSTK, etc.) to meet the needs of individual refineries.