Shell Catalysts & Technologies’ THIOPAQ O&G process was originally marketed by Paques BV as THIOPAQ for the treatment of biogas, which is produced by the anaerobic digestion of wastewater. Co-operation with Shell led to further development of the process for application at high pressure in Oil and Gas environments. 

It can be economically applied to projects recovering up to 150 t/d of sulphur. For the natural gas and petrochemical environments, the process is licensed by Paqell BV, a joint-venture company of Shell Global Solutions International BV and Paques BV.

THIOPAQ O&G technology offers a series of benefits: 
Reduced Operating Costs The expensive chemicals required for liquid redox processes are not necessary; only some caustic, make up water and nutrients are required. 
Reduced Capital Expenditure The main process operates at ambient temperature and does not require equipment such as burners and reboilers. The regeneration and sulphur recovery section always operates at ambient pressure and temperature, while the absorber column can still operate at high pressure. 
Ease of Operation The biologically produced sulphur is hydrophilic. This feature can eliminate plugging problems, which can allow for more efficient operator monitoring procedures. 
Safety An additional feature of the process is that can operate with no free H2S (no acid gas) after the bioreactor.


This new technology offers many advantages for low Sulphur capacity duties that were previously satisfied by Shell’s Sulferox technology. The Sulferox technology has successfully been deployed in more than 30 sites worldwide with capacities ranging from 0.1 to 20 t/d. The Thiopaq O&G technology with more than 20 references in the O&G sector, clearly demonstrates Shell’s drive to continually develop better and better solutions to address the environmental challenges facing the world and industry today. The original Thiopaq process has also been deployed at >250 biogas treatment facilities, spawning the development of the Thiopaq O&G variant.

Acid tank and Condensate polisher unit used in Thiopaq

The Thiopaq O&Q process relies on environmentally sound, naturally occurring bacteria.

As a compliant, sustainable, and cost-effective desulphurizer, Shell Catalysts & Technologies has been using this process for nearly two decades. Since 2002, eight commercial reference units have been established and seven additional units are in the design or construction phase. It’s a battle-tested process that gets results using a product of the environment to avoid more unsustainable alternatives.

Paqell Thiopaq O&G

We provide Paqell’s Thiopaq O&G, an innovative biological gas desulphurisation process that integrates gas purification to achieve sulphur recovery.

Sulferox Sour Gas Treatment

Our Sulferox process offers a flexible solution for sour-gas treatment, requiring less equipment and energy to operate than amine-Claus alternatives.

Natural Gas Technologies

Combining technical expertise with experience in upstream and downstream processes, we deliver fit-for-purpose designs as well as training and troubleshooting.