Shipboard carbon capture and storage is advancing, but technical, regulatory and economic hurdles remain.
While onboard carbon capture and storage (OCCS) technology promises a means of reducing CO2 emissions from conventionally fuelled vessels, the practicalities of integrating these systems, the readiness of port infrastructure, and the financial realities of adoption continue to provoke debate.
The webinar Onboard carbon capture challenges and breakthroughs, held 5 March 2025, brought together experts from the research, operational and regulatory spheres to discuss the latest developments in onboard carbon capture and the challenges it must overcome before achieving widespread deployment. The webinar was sponsored by CO2 Capture, Transport & Storage.
Solvang business development manager CCUS, Martha Nord-Varhaug Boge, detailed the real-world implications of these concerns through Solvang’s pilot project on board LPG carrier Clipper Eris. The vessel has been fitted with an amine-based carbon capture system, allowing for CO2 to be removed from the exhaust stream, liquefied and stored on board.
"We have installed two deck tanks, each with a capacity of 350 m3, giving us a total of 700 m3 of storage. That allows for a capture rate of around 70% over a 14-day voyage," she explained. The pilot is still in the early stages, and the team is evaluating efficiency losses and operational impact.
Fuel consumption increases were a central concern. "We expect somewhere between a 10-20% rise in fuel consumption at a 70% [CO2] capture rate," Ms Nord-Varhaug Boge noted. "But that is something we are testing now. There is a balance to strike between capture efficiency and energy demand."
SINTEF research scientist, Donghoi Kim, echoed this point, adding the energy penalty associated with onboard carbon capture is highly dependent on ship configuration and fuel type. "If waste heat from the engine can be effectively utilised, the penalty is lower, but if additional power is needed, the economics shift," he said.
Another point of discussion was whether onboard carbon capture is best suited to vessels running on conventional fuels, or alternative options such as LNG and methanol. "There has been an assumption that OCCS is mainly for LNG-fuelled ships," Mr Kim noted, "but our research indicates it may make more sense for oil-fuelled vessels, given the methane slip issues associated with LNG."
Even if technical barriers can be addressed, the question remains: what happens to the captured CO2 once a vessel reaches port?
This issue emerged as the largest concern among webinar participants, with 39% identifying a lack of infrastructure as the primary challenge to large-scale adoption, on par with the cost factor. Ports capable of receiving liquefied CO2 are few and far between, raising concerns about whether onboard capture systems will be viable for vessels with diverse trading patterns.
"Unlike pipelines that serve fixed routes, ships do not follow a predictable schedule," Ms Nord-Varhaug Boge observed. "That means we need a global network of discharge points, rather than isolated facilities."
CCSA UK director, Mark Sommerfeld stressed that regulatory frameworks remain incomplete. "The International Convention for the Prevention of Pollution from Ships (Marpol) does not currently classify captured CO2 as a waste stream. That creates uncertainty over how it should be handled legally," he said. "There’s also the question of liability — who takes ownership of the CO2 once it is offloaded?"
While some European ports, particularly in Norway and the UK, are exploring CO2 handling solutions, Mr Sommerfeld warned progress is slow. "We are seeing developments, particularly in the UK’s industrial clusters and the EU’s carbon capture networks, but we do not yet have the standardisation required for cross-border CO2 transport," he said. The issue of CO2 quality is also being debated. "If captured CO2 is not pure enough, it may require additional processing before it can be accepted into existing sequestration facilities, adding another layer of complexity," he said.
Ms Nord-Varhaug Boge highlighted purity concerns have been partially addressed in testing, "Our system produces CO2 that is 99.9% pure, but that remaining fraction is what needs further scrutiny. There is no room for large-scale purification on board, so ports and terminals will need to manage that step if required."
The regulatory landscape remains uneven. IMO’s recent greenhouse gas reduction strategy has set ambitious targets, but policy mechanisms are not yet in place to support onboard carbon capture. "We see a mix of regulatory drivers," Mr Sommerfeld explained. "The EU ETS includes OCCS in its framework, but FuelEU Maritime does not, which creates inconsistencies. We need clear, aligned policies that incentivise investment."
The high capital expense of installing OCCS, combined with increased fuel costs, raises concerns over return on investment. However, some argue OCCS could offer a lower-cost decarbonisation pathway compared with alternative fuels. "At current fuel price levels, onboard carbon capture is already cost-competitive with biofuels," Mr Kim stated. "We have calculated that, even at a relatively low carbon price, OCCS makes financial sense in certain scenarios."
Yet the viability of the business model depends heavily on carbon pricing and regulatory incentives. 39% of webinar participants identified carbon pricing and market incentives as the most critical factor in accelerating adoption, ranking above stricter regulations (31%) and technological advances (21%). "The reality is that if the cost of emitting CO2 rises sufficiently, onboard capture will become a necessity rather than an option," Mr Sommerfeld observed. "But we are not there yet. Current carbon pricing is too low to drive widespread adoption."
Ms Nord-Varhaug Boge believes a phased approach will be necessary. "We have designed our newbuilds to be OCCS-ready, but we are not rolling it out across the fleet immediately.
We need to see regulatory certainty and infrastructure development before large-scale investment makes sense," she said. "We also need incentives that reward technological solutions, not just fuel-switching. If OCCS is penalised under decarbonisation schemes while other solutions receive credits, adoption will stall."
The discussion underscored that while OCCS is no longer dismissed as unfeasible, it still faces unanswered questions. The technology itself is progressing, with pilot projects demonstrating early promise. Yet without regulatory alignment, port infrastructure, and a strong economic case, large-scale adoption remains uncertain.
Mr Kim was optimistic but realistic, "We have moved beyond the ‘if’ and are now in the ‘how’ stage. But making it work requires co-ordination across multiple sectors — shipping, ports, policymakers, and carbon markets all need to align."
Mr Sommerfeld echoed the sentiment, emphasising the role of OCCS must be seen within the broader decarbonisation landscape, "This is not a silver bullet, but it is a tool that can extend the life of existing vessels and help bridge the transition. Whether it becomes a major solution depends on whether we solve the outstanding infrastructure and policy challenges.".
source: riviera news
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