Directly capturing CO₂ from the ocean — Hitachi, MOL, and JAL sign MOU with goal of Japan's first technology demonstration

Hitachi, Ltd., Mitsui O.S.K. Lines, Ltd. (MOL), and Japan Airlines Co., Ltd. (JAL) decided to conduct Japan's first demonstration using "Direct Ocean Capture (DOC)," a technology directly separating and capturing CO₂ dissolved in seawater, on Kume Island, Okinawa Prefecture. The three parties signed a memorandum of understanding (MOU) on August 4.

In hard-to-abate sectors such as shipping and aviation, where moving solely with electricity is difficult and reducing CO₂ emissions is hard, offsetting residual emissions serves as an issue in addition to corporate emission reduction efforts. While demand for marine and air transport is expected to continue growing, expectations are increasing for CO₂ removal technology as one of those means to deal with rising emissions, thus the demand for creating direct-removal technologies through industrial methods is also increasing.

In addition, from the perspective of suppressing overseas procurement costs of carbon credits, which quantify greenhouse gas emission reductions and absorption/removal amounts so that companies can buy and trade them, in the future, the importance of establishing mechanisms domestically is heightening.

Therefore, the companies have invested in Captura Corp., a U.S. DOC technology development company, through investment subsidiaries and other entities. Toward domestic deployment of that technology, they have considered domestic demonstration until now while bringing together the knowhow of each company.

This demonstration is positioned as a first step toward constructing an island-type and domestically self-sufficient carbon economic zone in the future, utilizing captured CO₂ as raw materials for synthetic fuels such as "E-SAF," a next-generation synthetic aviation fuel with low environmental impact made by synthesizing captured CO₂ and renewable energy-derived hydrogen.

In the demonstration, installing container-type demonstration equipment on land along coasts near Kume Island, they aim to confirm applicability of DOC technology taking in seawater and separating CO₂, and acquire basic data regarding issues and environmental impacts to advance operations along domestic coasts.

In Kume Island, in addition to this demonstration, latest demonstration experiments taking advantage of locations such as ocean thermal energy conversion are conducted. Because the knowhow and human resources related to ocean research are gathered, it is an optimal environment for Japan's first demonstration of DOC technology.

Overview of DOC technology

DOC is a method that directly and stably separates and captures CO₂ from seawater. Seawater possesses the property of taking in carbon to a point where it balances with CO₂ concentrations in the atmosphere. Artificially extracting and removing CO₂ from seawater disrupts that balance, prompting the ocean to absorb CO₂ again from the atmosphere to make up for the deficit. By repeating this circulation, CO₂ concentrations in the atmosphere can be lowered effectively via the ocean. CO₂ concentrations in seawater are extremely high at approximately 100 to 150 times those in the atmosphere. It is looked at as a promising climate change measure capable of realizing CO₂ capture with low cost and low energy consumption.

Roles of the 3 companies

Hitachi: In the Hitachi Group's management plan "Inspire 2027," raising the sustainability strategy PLEDGES consisting of 7 pillars including decarbonization and resource circulation, it leads this initiative involving the 3 companies. Using high-precision measurement technologies of Hitachi High-Tech, it will measure and record operational statuses of equipment and water quality and environmental data such as CO₂ amounts in seawater and pH. Implementing physical AI directly feeding back analysis of these data to actual plant operation, it aims to search for and control energy-efficient operating conditions.

In addition, recording and verifying CO₂ capture amounts and power usage data, it contributes to constructing an MRV data foundation toward creating highly reliable carbon credits. This MRV takes initial letters of Measurement/Monitoring, Reporting, and Verification. It refers to a series of processes and mechanisms accurately measuring and reporting greenhouse gas (GHG) emission and reduction amounts, with third parties verifying them.

Furthermore, Hitachi Industrial Products, Ltd. advances considerations toward proposing and supplying core equipment required for commercial plants. Hitachi aims to establish intelligent DOC models originating from Japan through One Hitachi across the entire group.

MOL: In its management plan "BLUE ACTION 2035," the MOL Group raises environmental strategies as one of its main strategies, advancing initiatives in decarbonization fields as a social infrastructure company starting from the ocean. In this demonstration, taking advantage of local foundations built through comprehensive partnership agreements with Kumejima Town, Okinawa Prefecture, it handles constructing cooperation systems with local stakeholders and preparing demonstration environments.

Based on knowledge obtained in this demonstration, it aims to contribute to both sides: expanding initiatives regarding utilization possibilities of DOC technology, and creating new businesses and expanding regional initiatives in Kume Island.

JAL: In its GX strategy stated in "JAL Group Management Vision 2035," the JAL Group positions CO₂ removal technology as one of its initiatives. In this demonstration, alongside Japan Transocean Air and Ryukyu Air Commuter Co., Ltd. operating flights to Kume Island, taking advantage of regional cooperation, it handles promotional activities regarding the demonstration toward expanding recognition of DOC technology inside and outside the industry. Aiming at procuring E-SAF using CO₂ captured in the demonstration as raw materials in the future, the company is considering the usefulness of DOC technology.