Storing CO2 Underground: Practical Use of CCS Technology Essential for Decarbonization

Amid decarbonization efforts, technology to capture and bury carbon dioxide emitted from thermal power plants and other sources is increasingly important. There is an urgent need to improve the conditions in Japan to realize the practical use of the technology.

The government has set a target of reducing greenhouse gas emissions to net-zero by 2050.

To achieve this goal, the government is working to promote the utilization of renewable energy sources, such as solar power generation, but there are only a few suitable sites in Japan, making it difficult to rapidly expand the use of such energy sources. For the time being, there is no choice but to continue using thermal power generation.

Some industries, such as steel and chemical manufacturers, find it difficult to reduce CO2 emissions to zero in the current situation.

Under these circumstances, a technology called Carbon dioxide Capture and Storage (CCS) is attracting attention.

This technology separates and captures CO2 from the exhaust gases emitted from such facilities as power plants and factories, by using materials including special membranes, before transporting it by ship or pipeline to a storage site in the ocean. There it is sealed within a solid geological layer at a depth of at least about 1 kilometer to prevent leakage.

This technology can be deemed indispensable for efforts to decarbonize while maintaining a stable energy supply and industrial activities.

The government aims to put CCS into practical use by 2030. Some estimates suggest that storage of 120 million tons to 240 million tons per year will be necessary to achieve net-zero emissions by 2050.

The CCS technology itself is already established. The government has successfully stored 300,000 tons in experimental tests conducted in Hokkaido, and no leakage occurred during subsequent earthquakes.

Some entities, including a major electric power utility company, a steelmaker and a trading firm, are already making business plans for CCS off Kyushu and Hokkaido. It is hoped that the government will boost its support.

At the same time, there have been calls for relevant legislation because regulations for operators of the CCS technology are unclear.

In response, the government is set to submit new bills on CCS to the current Diet session to have it take effect this year.

Using a license system, the government will select CCS operators from applications, and once a license is granted, the operator will be allowed to conduct exploratory drilling to assess if a site is suitable and to actually store CO2.

The government will also make it mandatory for operators to monitor the stored CO2 to ensure there are no leakages. The bills stipulate that if local communities suffer damage due to leakage or other factors, operators will be held liable for compensation even if they were not negligent.

Ensuring safety is essential. The government and operators must do their utmost to gain the understanding of residents and fishermen in the vicinity to alleviate the concerns of local communities.

Another issue is cost reduction. Currently, capturing and storing CO2 is calculated to cost at least ¥10,000 per ton. It is hoped that the public and private sectors will work together to move forward with the development of technologies that can efficiently collect and transport CO2 at low cost.

(From The Yomiuri Shimbun, Feb. 27, 2024)