Technology

Technology Summary

Worley’s sulfur recovery technology is marketed under the Comprimo brand, encompassing Claus-based sulfur recovery units (SRUs) and tail-gas treatment systems to convert hydrogen sulfide (H₂S)–rich acid gases into elemental sulfur while minimizing SO₂ emissions.

Comprimo traces its origins to N.V. Comprimo, founded in Amsterdam in 1924 as an industrial refrigeration and chemicals contractor. By the 1950s, Comprimo had specialized in the Claus process for sulfur recovery, licensing its first units to Shell and other refiners. Through successive mergers—joining Stork Engineering in 1995 and Jacobs Engineering in 2000—the Comprimo name endured as a symbol of robust SRU technology. In 2023, Jacobs’s Comprimo business merged into Worley, creating Worley Comprimo, which now licenses over 1,200 SRUs globally and holds a >60 % share of active Claus units worldwide.

Process Flow

The Comprimo SRU typically comprises:

1. Acid Gas Preheat and Combustion
   Raw acid gas (H₂S-rich) mixes with substoichiometric air and enters the Claus furnace at 1,100–1,300 °C, where partial oxidation forms sulfur dioxide (SO₂) and water vapor.
2. Waste-Heat Recovery
   Hot effluent passes through a waste-heat boiler, generating medium-pressure steam and cooling the gas to ~350 °C.
3. Claus Catalytic Conversion
   Cooled gas enters sequential catalytic reactors (two or three stages), each containing alumina-based catalysts, where H₂S reacts with SO₂ per the Claus reaction (2 H₂S + SO₂ ↔ 3 S + 2 H₂O), yielding elemental sulfur vapor. Liquid sulfur is condensed and collected after each stage.
4. Tail-Gas Treatment
   Unconverted sulfur species (SO₂, COS, CS₂) are processed via one of Comprimo’s tail-gas solutions:
   • BSR-Amine: Hydrogenation over CoMo catalysts converts residual sulfur compounds to H₂S, which is absorbed in an MDEA solvent and recycled to the Claus furnace.
   • SUPERCLAUS^®/EUROCLAUS^®: Proprietary selective-oxidation catalysts in a final reactor convert H₂S directly to elemental sulfur using controlled oxygen addition without the reverse Claus reaction.

Key Chemical Reactions

• Thermal Oxidation: 2 H₂S + 3 O₂ → 2 SO₂ + 2 H₂O

• Claus Conversion: 2 H₂S + SO₂ ↔ 3 S + 2 H₂O

• Selective Oxidation (SUPERCLAUS^®): H₂S + 0.5 O₂ → S + H₂O

Process Performance and Yields

Claus Alone:

• Two catalytic stages: 94–97 % sulfur recovery
• Three catalytic stages: ~98 % recovery

With Tail-Gas Treatment:

• BSR-Amine: >99.8 % overall recovery
• SUPERCLAUS^®/EUROCLAUS^®: 99–99.5 % without additional cleanup; >99.9 % when combined with WSA cycles.

Energy Integration:

• Waste-heat boilers and condensers generate up to 80 % of steam requirements; low-pressure steam from condensers offsets 30–40 % of energy demand.

Commercial Experience

Global Reach: Over 1,200 Comprimo-designed SRUs licensed in 80+ countries, representing >60 % of all installed Claus units worldwide.

Major Projects:

• Grassroots refinery complex in Tuban, Indonesia (2×1,040 t/d SRU trains, 2 tail-gas trains)
• Modular SRU retrofit at Kuwait Petroleum Europoort, Rotterdam employing off-site construction of nine 90 t modules.

Digital Solutions: Worley Comprimo Insight and Immerse platforms provide digital twins and real-time dashboards to optimize performance and reliability.

Reference

1. Worley Chemetics + Worley Comprimo Sulphur Solutions PDF.
2. BC Insight, “100 years of Comprimo,” July 2024.
3. J.A. Lagas et al., THE SUPERCLAUS PROCESS, 1988.
4. H. Njuguna & J. Lewis, Process Optimization—Worley Comprimo, Hydrocarbon Processing, 2023.
5. Worley Investor Day, May 2024.
6. J. Lewis et al., "New state-of-the-art in sulfur recovery", Hydrocarbon Processing
   • Part 1. Process Optimization, Dec 2022
   • Part 2. Environmental Benefits, Jan 2023.
   • Part 3. Economic Benefits, March 2023.