Onboard Carbon Capture Gets Its First Real Compliance Value Under the EU ETS

Project CAPTURED, a Global Centre for Maritime Decarbonisation (GCMD) initiative, has secured two regulatory milestones for onboard carbon capture and storage (OCCS): formal recognition under the EU Emissions Trading System allowing verified onboard-captured CO2 to be deducted from a vessel's EU Allowance surrender requirement, and in-principle support from the International Maritime Organization for recognizing carbon mineralization, converting captured CO2 into stable industrial materials, as a form of permanent CO2 storage. Both milestones build on a pilot completed in June 2025 that demonstrated CO2 captured onboard a vessel could be offloaded ship-to-ship, transported overland, and permanently bound through mineralization.

Why EU ETS Recognition Is the Commercially Consequential Piece

Regulatory acceptance of a compliance pathway is different from technical feasibility, and this is the first time onboard-captured CO2 has been given an explicit deduction mechanism against a real compliance obligation. To qualify, the CO2 has to be chemically bound permanently in eligible products, a bar Project CAPTURED demonstrated its mineralization pathway can clear. That gives captured CO2 tradeable compliance value under the EU ETS specifically, rather than remaining a technology proof-of-concept with no defined route to counting against a shipowner's actual carbon costs.

What the IMO's In-Principle Support Adds

The IMO already accepts geological sequestration as permanent CO2 storage; this proposal, submitted to the organization's Marine Environment Protection Committee, extends that recognition to carbon mineralization as a second accepted pathway. That matters because it gives captured CO2 an additional destination beyond storage. Mineralization allows captured CO2 to become a feedstock for industrial products, extending its use beyond the shipping value chain itself, rather than requiring every tonne captured onboard to be sequestered underground.

The Actual Numbers Behind the Pilot

GCMD's life cycle assessment found the pilot achieved a 7.9% net greenhouse gas reduction at a 10.7% gross onboard capture rate, with an optimized value chain at the same capture rate projected to deliver 17.8% GHG savings. CO2 purity was maintained above 99.95% by volume at all custody-transfer points, a technical detail relevant to why regulators were willing to treat the captured CO2 as a verifiable, tradeable quantity rather than an estimate. The pilot involved 11 partners across maritime and industrial sectors, including SMDERI-QET, Evergreen Marine Corp, Zhoushan Dejin Shipping and Greenore/Baorong.

Why This Sits Differently From Fuel-Switching Approaches

Most of the maritime decarbonization stories in this series, methanol bunkering, marine biofuel blend limits, ammonia-ready vessels, address emissions by changing what ships burn. OCCS addresses emissions after combustion, on vessels that continue running on conventional fuel, which makes it a complementary rather than competing pathway: a way to cut emissions from the large share of the existing fleet that will keep running on conventional fuels for years before fuel-switching reaches scale, rather than a replacement for the fuel transition itself.

Source: Global Centre for Maritime Decarbonisation, 22 July 2026.