Onboard carbon capture technology could keep ships ahead of IMO targets, report shows

May 6, 2025, by Sara Kosmajac

Incorporating carbon dioxide (CO2) captured from heavy fuel oil (HVO) combustion onboard ships into concrete production provides the highest emissions reduction—up to 60%—among all utilization pathways, a new study suggests.

The Global Centre for Maritime Decarbonization (GCMD) recently performed a life cycle assessment (LCA) to explore the potential of onboard carbon capture and storage (OCCS) in slashing greenhouse gas (GHG) emissions.

More precisely, the study, which was dubbed “Colossus” (Carbon capture, offloading, onshore storage, utilization and permanent storage), was aimed at evaluating GHG emissions and the costs associated with OCCS across the entire carbon value chain, taking into account the emissions from fuel production, transport and use to CO2 capture onboard the vessel and its final disposition.

“As we face an increasing array of decarbonisation solutions spanning different industries and value chains, coupled with the challenges of quantifying and elucidating carbon flows from source to sink, including their re-use, there is a pressing need for a comparable means to understand their net abatement impact,” Lynn Loo, Chief Executive Officer at GCMD highlighted.

Representatives from GCMD have elaborated that the LCA explored five OCCS technologies with six marine fuel options and three post-capture scenarios.

Among OCCS solutions examined, the study—which used a well-to-wake (WtW) GHG emissions of 93.3 gCO2eq/MJ for HVO as a baseline—reportedly quantified various post-capture scenarios with conventional monoethanolamine (MEA)-based OCCS, which is believed to be the most mature among all solutions of this type in the industry.

According to GCMD, the key findings of the analysis were:

fixing the captured CO2 in concrete can increase GHG emissions savings from 29% to 60% by partially displacing the need for carbon-intensive cement in applications ashore;
the usage of conventional MEA-based OCCS can lead to a WtW GHG emissions reduction of 29% for an HFO-fueled ship;
replacing HFO with bio-LNG or biodiesel from used cooking oil can result in emissions savings for a vessel deploying MEA-based OCCS from 69% to 121%, respectively;
post-capture carbon dioxide transport and storage add minimal emissions, when the CO2 is transported 1,000 km (about 1%);
since captured CO2 can also be used to produce e-methanol with renewable electricity, this can allow the ship that consumes this clean energy source to claim a 17% GHG emission saving;

In addition to this, per the study, the cost of avoided carbon is estimated at $269–405/tCO₂ for a 40% capture rate on a medium range (MR) tanker, considering a full-scale installation of an OCCS system with full heat recovery.

As informed, the LCA has also underscored that an HFO-powered unit adopting MEA-based OCCS at 40% gross capture can, on a WtW basis, maintain an equivalent GHG Fuel Intensity (GFI) below the direct compliance target until 2032. LNG-powered ships with the same system can remain compliant through 2035, GCMD has said. Moreover, if fossil fuels are fully swapped out for biofuels, the organization has shared that OCCS has the potential to slash emissions enough to meet even the tougher targets set for 2040.

Carbon capture through the looking glass

Despite its potential to help the maritime transportation industry decarbonize, a number of challenges within the OCCS sphere need to be addressed. Namely, according to an industry analysis performed by GCMD and its partners in October last year, the main stumbling blocks for this technology include recurring additional costs due to fuel penalties, amine solvent replenishment, manpower, maintenance and offloading services.

What is more, the project partners postulated that, as the offloading of captured carbon dioxide is still in its infancy, it is hindered by a lack of clear national and port-level regulations for tracking and handling its final disposal.

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Compounding the issue, most ports currently lack the infrastructure needed to offload and store captured carbon efficiently. Specifically, as per GCMD, the UK’s classification society Lloyd’s Register (LR) and ARUP, only a limited number of ports have the necessary infrastructure to offload liquefied CO2 (LCO2).

Because of this, the three partners, who worked on this examination together, have emphasized that the shipping industry has to develop a more collaborative ecosystem in order to reach net zero by 2050.