Japan to Begin Storing CO2 Under the Sea Near Akita

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Carbon capture and storage (CCS), a crucial strategy for combating global warming, has officially begun in Japan. The technology will be used to capture and store CO2 emissions from industries such as steel production and thermal power generation.

The captured CO2 will be injected into deep geological formations beneath nine offshore areas, including the waters off Akita Prefecture. Pilot tests and project planning are underway, with full-scale operations scheduled to begin in fiscal 2030.

In Akita, the plan is to capture and store approximately two million tons of CO2 annually. Efforts to reuse CO2 are also expected to drive industrial growth.

Geological Storage

Hideki Shigematsu, head of the CCS Business Promotion Unit at Itochu Corporation, explained the project during a seminar hosted by Akita Prefecture in late October.

"CO2 will be injected into sandstone layers located more than 800 meters below the seabed," he said. "The seabed itself lies 100 to 400 meters beneath sea level, approximately 20 kilometers offshore from Akita and Yurihonjo City."

Sandstone, which has gaps between its particles, is suitable for CO2 injection. The material is also used as a reservoir for oil and natural gas.

Shigematsu highlighted, "The sandstone layers are capped by highly impermeable rock formations, such as mudstone, which ensure stable storage."

Partnerships and Industry Focus

The project will initially focus on industries such as steelmaking and cement production, with plans to expand operations across a broader area. The joint venture involves major emitters such as Nippon Steel and Taiheiyo Cement, alongside Taisei Corporation, which is overseeing facility design.

Carbon capture and storage (CCS) involves separating and capturing CO2 generated from processes such as coal, oil, and gas combustion, or cement production. 

The captured CO2 is liquefied at low temperatures — similar to natural gas — and transported in specialized tankers to storage facilities. From there, it is injected via wells into offshore geological formations through seabed pipelines.

Japan's Emissions and Storage Capacity

According to the Ministry of Economy, Trade, and Industry (METI), Japan's CO2 emissions totaled 1.037 billion tons in fiscal 2022. With multiple CO2 separation and capture technologies already commercialized, the government aims to capture and store 120 to 240 million tons annually by 2050.

Japan's storage capacity, including under the seabed, is estimated at up to 240 billion tons. Pre-surveyed areas alone could accommodate 16 billion tons. This would be enough to meet the government's target for the next 100 years.

The Japan Organization for Metals and Energy Security (JOGMEC) identified nine potential sites for this project in June. These include offshore areas in the Sea of Japan near Akita, the Tohoku region, the Tokyo metropolitan area, and the Malay Peninsula.

In the Akita offshore project, approximately 1.5 million tons of CO2 will be captured annually from Nippon Steel's Kyushu Steel Works Oita Area and Taiheiyo Cement's DC Kawasaki Plant. The CO2 will then be transported to a storage facility planned for either Akita Port (Akita City) or Funakawa Port (Oga City).

"Globally, 41 CO2 storage projects are operational, with another 351 under development. To date, no cases of CO2 leakage from storage formations have been reported," emphasized Shigematsu. Details on the safety of CO2 storage are available on the organization's website.

Producing Synthetic Fuels

The development of CO2 storage facilities offers tangible benefits to local communities. One key advantage is the capture of CO2 emissions from local waste incineration plants. According to the environment ministry, Japan's waste incineration facilities emitted approximately 43 million tons of CO2 in fiscal 2019.

Although often regarded as a nuisance, CO2 can also serve as a valuable industrial resource. It is essential for producing dry ice, shielding welding areas, and supporting medical applications in its gaseous form. Additionally, CO2 is widely used in the production of carbonated beverages.

With the expected growth of hydrogen production in Akita, CO2 could be converted into products like e-methane, an alternative to city gas. It could also be used to create e-fuels such as gasoline, diesel, kerosene, and jet fuel. Additionally, CO2 could be transformed into e-methanol, a key raw material for chemical manufacturing.

"For CCS to gain widespread social acceptance, it must deliver tangible benefits to the local community. Our goal is to advance the project in close collaboration with the region," said Shigematsu.

Trends in CO2 Capture and Storage 

CCS is gaining traction worldwide, with active projects underway in the United States, the European Union, Canada, Australia, and ASEAN nations. As of 2023, the total capacity of CO2 captured or planned for capture was estimated at approximately 350 million tons.

In Japan, the government approved the Green Transformation (GX) Promotion Strategy in July 2023, aiming to commence full-scale CCS operations by 2030. 

To facilitate this, the CCS Business Act was enacted in May 2024, establishing a legal framework for CO2 storage projects. A notable pilot project in Tomakomai, Hokkaido, successfully stored 300,000 tons of CO2 by 2019.

The government is exploring measures to reduce project costs, support operators, and implement systems for monitoring stored CO2.

Reflections from the Author

The rapid expansion of digital communication is supported by large-scale data centers, which consume enormous amounts of electricity. Energy reliance is also increasing in homes and offices. At the same time, efforts are underway to transition incinerators and automobiles from fossil fuels to electricity.

To address the growing demand for electricity and advance decarbonization, wind and solar power generation have expanded rapidly. However, both have raised environmental concerns. European manufacturers that rushed into electric vehicle (EV) production are now losing momentum.

It seems wise to preserve systems capable of operating on non-electric energy sources, provided they meet environmental standards. Carbon capture and storage could become a cornerstone of this balanced approach.

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Author: Tomoaki Yatsunami, The Sankei Shimbun

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