How to apply CO2 capture on HFO-fuelled ships?

by | Oct 8, 2025 | Emissions, Energy transition, Maritime research, News, Shipping

The Hanze Gendt will be used to collect emissions data that will be used to develop CO2 capture for HFO-fuelled ships (photo Flying Focus)

While heavy fuel oil (HFO) accounts for about sixty per cent of global shipping fuel use, effective carbon capture technologies for this type of fuel are still lacking. Within the CAROS project, Carbotreat, Conoship, Hanzevast Shipping, TNO and DNV explore the feasibility of applying CO2 capture technology to HFO-powered ships.

Building on previous and current R&D collaborations such as EverLoNG, LNG-Zero, and Blue Horizon, which focus on carbon capture on LNG-fuelled ships, CAROS tackles the unique challenges posed by HFO. As a heavier and more polluting fuel, HFO is expected to cause faster degradation of the solvents used in CO2 capture systems — posing serious limitations to current technologies.

Also read: Wärtsilä brings carbon capture to shipping market

Three lines of research

The CAROS project is structured around three core research activities:

  1. Desktop study: A literature review and data analysis of existing knowledge on HFO fuels, exhaust gas composition, and the interaction between HFO emissions and solvent degradation.
  2. Onboard measurements: Emissions data will be collected aboard the Hanze Gendt (an HFO-fuelled vessel of Hanzevast Shipping) to analyse real-world exhaust gas composition, with a focus on contaminants that may harm solvents.
  3. Test setup: A lab-based CO2 capture system will be built and connected to a two-stroke HFO combustion engine. Long-duration tests (1000 and 2000 hours) will be conducted using different solvents, informed by the findings of the previous two research activities.

The results will indicate to what extent current carbon capture systems — originally developed for LNG — must be modified to be effective and economically viable for use on HFO-fuelled vessels.

Also read: Value Maritime and MOL complete carbon capture first

Full-chain collaboration

The strength of the CAROS project lies in the diverse and complementary expertise of its partners:

  • Carbotreat Maritime specialises in onboard CO2 capture systems and is responsible for building the test facility.
  • Conoship International engineers safe integration of carbon capture systems into ship designs and brings naval architecture expertise to this project.
  • Hanzevast Shipping provides the vessel Hanze Gendt for real-world measurements and contributes operational knowledge of HFO-fuelled shipping.
  • Dutch applied research organisation TNO delivers models, conducts measurements, and analyses data.
  • DNV supports the project with safety evaluations and additional exhaust gas measurement expertise.

Also read: Maritime Master Plan funding for carbon capture on LNG vessel

Gaining time

‘This project is a crucial step toward reducing emissions from the existing global fleet,’ says Frank Sanders, Managing Director of Carbotreat and leader of the consortium. ‘The majority of vessels still run on HFO. If we can capture CO2 from those ships, we gain valuable time in the transition to a climate-neutral shipping industry.’

Project CAROS is made possible by a grant from the Dutch Ministry of Economic Affairs as part of the “Maritime Innovation Projects 2024” programme.

Picture: The Hanze Gendt will be used to collect emissions data that will be used to research CO2 capture for HFO-fuelled ships (photo Flying Focus).