The European Maritime Safety Agency (EMSA) estimates that the onboard carbon capture and storage systems (OCCS, for its acronym in English) could reduce emissions 'from well to wake' (Well-to-Wake, WtW) of ships by between 29% and 44%. In its study published on February 13, 2026, the agency adds that, in combination with biofuels, the reduction could reach up to 120% considering the full life cycle.
The report, consisting of 291 pages and prepared by DNV on behalf of EMSA under the framework contract EMSA/2024/OP/0025, is to date the most comprehensive analysis of the potential of these technologies to contribute to the decarbonization of the maritime sector, in a context marked by the International Maritime Organization (IMO) targets to reduce carbon intensity by 40% by 2030 and achieve net zero emissions by around 2050.
OCCS systems present considerable potential for significantly reducing maritime transport emissions. However, this saving comes with an energy cost that the report places between 9% and 30%, resulting from the additional fuel consumption necessary to generate the energy required for the regeneration of solvents, compression, and liquefaction of captured CO₂. EMSA also identifies other environmental impacts that must be taken into account, such as the degradation of amine-based solvents —primarily monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA)— and the management of generated by-products, aspects that condition both the design of the system and the operating procedures.
The study analyzes the different carbon capture systems currently available —pre-combustion, post-combustion, oxy-combustion, and their combinations— and their degree of technological maturity. The most developed method is post-combustion by chemical absorption, with capture rates from 30% to 90% according to the analyzed results. The report accounts for over 15 pilot projects and chemical absorption installations worldwide, including initiatives like the CC-Ocean project by K-Line and Mitsubishi (which achieved CO₂ purity higher than 99.9% in an 88,000-ton bulk carrier), the demonstration by SMDERI and Evergreen Marine in a 14,000 TEU container ship with a capture rate of 40%, or the EverLoNG project, funded by the EU, which achieved capture rates of up to 85% in LNG-powered ships. The system installed by Solvang and Wärtsilä on the gas tanker Clipper Eris showed CO₂ reductions of up to 70%.
Other options, such as the use of membranes, cryogenic capture, electro-separation, or mineralization, appear as potential alternatives but with a lower level of technological maturity. Pre-combustion methods, such as LNG reforming or pyrolysis, raise technical complexity and require integration with hydrogen-based propulsion systems.
To assess the practical viability of these systems, EMSA selected six types of representative vessels from the European fleet: Suezmax tankers, 15,000 TEU container ships, Ro-Pax ferries, LNGC gas carriers of 174,000 m³, feeder container ships of 1,700 TEU, and MR tankers. The selection responds to their contribution to CO₂ emissions and operational profiles. Ocean-going vessels —tankers, large container ships, and gas carriers— were prioritized due to their high levels of emissions and travel characteristics that favor prolonged operation of OCCS systems. Short-distance navigation vessels, such as feeders and Ro-Pax, have the advantage of frequent port calls, although they present challenges regarding space and safety for equipment integration.
From an economic perspective, EMSA points out that newly built vessels prepared for the installation of OCCS systems have the lowest abatement costs, while retrofit projects are penalized by the complexity of integration and a greater impact on fuel consumption. Fuel prices and CO₂ disposal costs exert the greatest influence on the total abatement cost, followed by CAPEX and maintenance, while the cost of solvents has a marginal impact. Although the initial investment is high, the study indicates that the competitiveness of these solutions will largely depend on the evolution of carbon prices within the EU ETS system, a factor that may enhance their profitability in the medium and long term. According to DNV projections, the gradual adoption of OCCS between 2030 and 2040 could mean capturing about 4 million tons of CO₂ per year, a figure that would rise to approximately 110 million tons annually by 2050.
The agency also points out that large-scale deployment depends on an operational CCUS (Carbon Capture, Usage and Storage) value chain: the existence of port infrastructure for unloading liquefied CO₂ (LCO₂), transport networks, and permanent storage options. The report identifies an emerging network of CO₂ terminal projects in European ports, including the Antwerp@C export hub in Antwerp-Bruges, the CO₂next project in Rotterdam, the D'Artagnan hub in Dunkirk, the APOLLOCO₂ project in Piraeus, and other initiatives in Zeebrugge, Ghent, Gdansk, Wilhelmshaven, and Marseille-Fos. The coexistence of this first European benchmark, the Ever Top vessel from Evergreen, which has already completed three verified CO₂ unloadings in Shanghai and Rotterdam, suggests that the technology is approaching its commercial operation phase.
In terms of safety, the HAZID/HAZOP risk assessments carried out for the different types of ships indicate that OCCS systems can operate within acceptable thresholds. The study did not identify high-category risks, although most events were classified as medium risk, which requires mitigation measures such as corrosion-resistant materials, leak detection systems, ventilation standards, and specific crew training. Nevertheless, EMSA warns of the existence of significant regulatory gaps that will require international coordination—both in the IMO and the EU—to avoid fragmented regulatory frameworks that hinder the adoption of this technology.