The State of Onboard Carbon Capture At Sea in 2026

Shipping has always been a practical industry. When problems need solving, the sector finds its way to workable answers, even if the path is rarely straightforward. Decarbonization is proving no different.

By Paul Morgan (gCaptain) – Low-carbon fuels are coming, but not quickly enough or cheaply enough to cover the entire fleet through the 2030s. Onboard carbon capture and storage, or OCCS, is emerging as one of the more credible near-term bridges, and a landmark new report from Lloyd’s Register Advisory, commissioned by the International Chamber of Shipping, has set out the most comprehensive independent assessment of where the technology actually stands.

The conclusion is broadly encouraging, if hedged with honest caveats. OCCS is feasible. It has been demonstrated at sea across multiple vessel types. Capture rates of 70–95 percent are achievable with the most mature systems. But scalable commercial deployment depends on solving three interlocking problems: integration into existing ship designs, the creation of port infrastructure to receive captured carbon, and a regulatory framework that actually recognizes and rewards what operators are doing.

Post-combustion systems, which treat exhaust gas after it leaves the engine, dominate the current market. Amine chemical absorption is the most developed option. The exhaust stream passes through a liquid amine solvent that selectively absorbs CO2. The solvent is regenerated using heat, releasing a concentrated CO2 stream that is compressed, dried, and liquefied for storage in Type C pressure tanks. The process imposes a fuel penalty of roughly 9–30 percent, depending on configuration and waste-heat recovery. Technology readiness sits at TRL 7 to 8, meaning real-world pilots have been completed and commercial hardware is available.

Calcium looping uses a different chemistry. Calcium oxide reacts with CO2 in the exhaust to form solid calcium carbonate, which is stored onboard in a stable, non-toxic form before being offloaded in port using conventional equipment. The material has potential for use as an industrial commodity in cement and construction, offering a direct circular economy link. The mass penalty is significant at a ratio of 2.27 to 1 against the CO2 it contains, but the approach avoids cryogenic storage entirely. This pathway sits at TRL 6 to 7, with successful shipboard pilots completed.

Membrane separation, which uses selective polymer membranes to divide CO2 from exhaust gas, is compact and avoids chemical handling. Capture rates are somewhat lower, in the 60–85 percent range. Cryogenic separation delivers a very high-purity product but requires substantial electrical power, making it best suited to LNG carriers where cold energy from boil-off gas can be repurposed. Pre-combustion thermocatalytic decomposition, or TCD, cracks methane from LNG into hydrogen and solid carbon before combustion, avoiding CO2 formation at the source entirely. It is primarily relevant for LNG carriers and gas-fueled vessels.

So who is leading the charge? Wärtsilä is perhaps the most recognizable name. The Finnish engineering group has been developing marine carbon capture since 2019, and its amine-based system achieved TRL 8 with a first installation on a Solvang LPG tanker in 2025, designed to capture around 70 percent of the vessel’s CO2 emissions. CSSC 711, developed by China State Shipbuilding Corporation, has demonstrated the furthest commercial reach, completing the first overseas offloading operation at Rotterdam after installations on an Evergreen container vessel and an 82,500-deadweight bulk carrier.

Value Maritime has installations across tonnage managed by Berge Bulk, Eastern Pacific Shipping, and MOL. Seabound, a London-based startup pursuing calcium looping, has completed the first full-scale commercial installation on the UBC Cork cement carrier in partnership with Heidelberg Materials, with captured calcium carbonate flowing directly into cement production. Korean builders Hanwha Ocean and Panasia have demonstrated amine-based systems on LNG carriers and container vessels, achieving capture rates approaching 90 percent. Chinese developer Sinotech has reduced system weight by 40 percent across successive generations, addressing one of the persistent barriers to retrofit integration.

LNG carriers and large tankers are the strongest near-term candidates. LNG carriers already operate extensive cryogenic systems, generate substantial waste heat from their propulsion and cargo-handling arrangements, produce relatively clean exhaust, and carry crews experienced in complex fluid management. Large crude tankers benefit from ample deck space, auxiliary boiler capacity for solvent regeneration, and operational familiarity with hazardous-liquid handling from everyday cargo practice.

Containerships present a more mixed picture. The primary constraint is the trade-off between equipment footprint and revenue-generating TEU capacity. Against that, frequent and regular port calls reduce storage endurance requirements, waste-heat availability is strong, and calcium looping systems using ISO containers integrate naturally with existing cargo-handling logistics. Liner services, with predictable port rotations, are better placed than tramp operators to guarantee offloading opportunities.

Bulk carriers face the most challenging environment. Deck space is largely consumed by cargo-handling equipment, waste-heat availability is limited, and crews have limited familiarity with chemical effluent management. The LR Advisory report identifies this sector as having the highest structural barriers to OCCS deployment, with the partial exception of cement carriers or short-sea operators on regular schedules where calcium looping with containerized solids handling is technically viable.

What happens to the carbon captured? Permanent geological sequestration is the most established downstream pathway, with CO2 transported in liquefied form and injected into depleted oil and gas fields or deep saline aquifers. Norway’s Northern Lights project has established the world’s first open-access, cross-border CO2 transport and storage service, receiving carbon by ship, with Phase 1 operational capacity of 1.5 million tonnes per annum, expandable to 5 million. Rotterdam’s Porthos project and Denmark’s Greensand development represent the next tier of infrastructure approaching readiness.

Industrial utilization offers a complementary pathway. Captured CO2 is used in food and beverage production, greenhouse agriculture, and increasingly synthetic fuel production. A Panasia installation on an HMM container vessel demonstrated the capture-to-green-methanol pathway directly. For calcium looping and sodium hydroxide systems, the solid or mineralized product is itself a marketable commodity, providing a direct revenue offset against operational costs. Seabound’s cement carrier model is the clearest working example.

The critical bottleneck is port reception infrastructure. The ICS report identifies fewer than 10 ports globally with existing or firmly announced CO2 reception facilities, almost all in Northern Europe. For most of the world’s major port clusters, the infrastructure simply does not yet exist, and purity requirements are strict, typically 95–99.9 percent CO2, demanding careful system design and custody-transfer management to avoid quality rejection.

Project REMARCCABLE, the GCMD-led feasibility study for retrofitting an amine system onto the MR tanker Stena Impero, estimated capital expenditure of $3.6 million and annual operating costs of $30,000, producing an abatement cost of $69 per tonne of CO2. That figure is currently well above prevailing carbon prices in most jurisdictions. The Maersk Mc-Kinney Moller Centre for Zero Carbon Shipping found that installation costs across vessel types run between 20 and 70 percent of newbuild price, with smaller ships facing disproportionately higher costs.

Seabound’s calcium looping approach is expected to be considerably less expensive to install than conventional amine-based systems because it avoids onboard solvent regeneration, CO? liquefaction, and cryogenic storage. While the company has not publicly disclosed system pricing, the MARAD techno-economic analysis notes that calcium looping substantially reduces onboard equipment requirements and electrical demand, although operating economics remain heavily influenced by sorbent costs.

The economics improve materially under carbon pricing. The only near-term regulatory instrument providing a direct financial incentive is the EU Emissions Trading System, under which CO2 demonstrably captured and permanently stored is excluded from reportable emissions. IMO’s short-term measures—EEDI, EEXI, and CII—currently offer no credit for OCCS, a gap the ICS report identifies as a significant brake on early adoption.

The regulatory position is that MEPC has adopted a work plan for developing a full OCCS regulatory framework, with finalization targeted for 2028. Lifecycle accounting guidelines are under development, and there is acknowledged intent to incorporate onboard capture into future compliance frameworks, but the methodology remains formally undefined. FuelEU Maritime does not currently credit OCCS and will require a formal methodology update, with a scheduled review by the end of 2027.

Bilateral agreements between consenting states are meanwhile enabling cross-border CO2 transport ahead of formal international instruments. Five Northern European countries concluded coordinated arrangements in 2024 allowing cross-border CO2 shipment for North Sea storage. The UK-Norway corridor is the most legally mature, with Northern Lights explicitly designed to receive foreign CO2 by ship.

Classification societies are providing the most operational rules currently available. DNV published dedicated OCCS class requirements that entered into force in January 2025. Lloyd’s Register has introduced an EACCS notation covering the full capture-to-offload cycle, and IACS is developing a Unified Requirement to establish a common baseline across member societies.

The decade ahead will determine whether onboard carbon capture becomes a mainstream compliance tool or remains a niche solution for the most technically favored vessel segments. Given the scale of the regulatory challenge facing shipping and the pace at which alternative fuels are becoming available at scale, the trajectory points toward significant expansion, provided the infrastructure and the regulatory framework continue moving in the right direction.

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