Hitachi, MOL and JAL launch Japan ocean carbon capture pilot

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Hitachi, Mitsui O.S.K. Lines (MOL) and Japan Airlines (JAL) have signed a memorandum of understanding to conduct Japan’s first pilot test of Direct Ocean Capture technology, targeting a potential domestic source of carbon removal for hard to abate transport sectors.

The pilot will take place on Kume Island in Okinawa Prefecture and will test technology designed to separate and capture carbon dioxide dissolved in seawater. The companies plan to assess whether the system can operate effectively using local seawater while gathering data on operational requirements and environmental impacts.

The project also creates a potential link between ocean based carbon removal and future synthetic fuel production. Hitachi, MOL and JAL said recovered CO2 could ultimately be used as a feedstock for fuels including E SAF.

The pilot will use containerized equipment installed on land on Kume Island. Seawater will be drawn into the system, where dissolved CO2 will be separated and captured.

The companies selected Kume Island partly because it already hosts ocean research and energy projects, including Ocean Thermal Energy Conversion. The concentration of marine research expertise and infrastructure provides a base for testing how Direct Ocean Capture, or DOC, could operate under Japanese coastal conditions.

The partners aim to establish foundational data that could support deployment at other locations along Japan’s coastline.

That could be significant for shipping and aviation. Both sectors face substantial technical challenges in eliminating emissions because many operations cannot readily be electrified using currently available technology.

Carbon removal could therefore complement direct emission reductions, particularly where residual emissions remain difficult or expensive to eliminate.

DOC approaches the carbon removal problem differently from technologies that extract CO2 directly from ambient air.

Seawater naturally absorbs atmospheric carbon dioxide until an equilibrium is reached between concentrations in the ocean and atmosphere. Removing dissolved CO2 from seawater alters that balance, allowing the treated water to absorb additional CO2 from the atmosphere.

The process effectively uses the ocean as an intermediary between atmospheric carbon and the capture equipment.

According to the companies, the concentration of CO2 in seawater is approximately 100 to 150 times higher than in the atmosphere. That difference could potentially allow DOC systems to capture carbon with lower energy consumption and costs than some alternative engineered removal technologies.

The pilot will provide practical evidence on whether those potential advantages translate into operations under Japanese conditions.

Hitachi, MOL and JAL have each invested in US based DOC technology developer Captura Corp. through their respective investment subsidiaries and other channels.

The companies have subsequently worked together to examine how Captura’s technology could be deployed in Japan, combining their experience across technology, shipping and aviation.

The Kume Island project represents the first physical step in that effort.

Beyond demonstrating the capture process itself, the partners intend to examine how recovered CO2 could be used locally. They will also explore environmental education and promotional activities associated with the pilot as part of a broader effort to develop ocean related economic activity.

The longer term ambition is to establish what the companies describe as an island based, domestically self sufficient carbon economy.

The involvement of MOL and JAL places the project directly within two transport sectors facing particularly difficult decarbonisation pathways.

Shipping is examining alternatives including methanol, ammonia, biofuels, synthetic fuels and efficiency technologies, while aviation is increasingly focused on sustainable aviation fuel and synthetic alternatives. Many of these pathways require either sustainable carbon feedstocks or credible mechanisms for addressing residual emissions.

The Japanese partners also see a strategic argument for developing carbon removal capacity domestically.

Demand for engineered carbon removal is expected to increase as companies pursue decarbonisation targets, potentially increasing competition for international carbon credits. Establishing domestic removal technology could reduce dependence on overseas credits and provide greater control over future carbon costs.

The Kume Island pilot could also test whether captured carbon can become an industrial input rather than simply a material requiring permanent storage.

Hitachi, MOL and JAL said the recovered CO2 could eventually serve as a feedstock for synthetic fuels such as E SAF. Such a system would connect ocean carbon capture with fuel production for sectors that are themselves seeking alternatives to conventional fossil fuels.

The immediate focus, however, remains the performance of the containerized pilot equipment and its interaction with the surrounding marine environment. Data collected on Kume Island will be used to evaluate operational challenges, environmental effects and the feasibility of expanding DOC technology to other coastal locations in Japan.