An ambitious project to combat global warming is planned in Chiba Prefecture, which would collect carbon dioxide emitted from factories in the prefecture along Tokyo Bay for storage deep under the seabed. 

The CO₂ will be sent through a pipeline crossing the Boso Peninsula, where the project has come under fire from some communities. 

The companies engaged in the project have already finished briefing the municipalities and started information sessions for local residents, with some raising concerns.

The project is part of countermeasures against global warming through a process described as carbon dioxide capture and storage (CCS).

According to documents, the project in Chiba Prefecture, called the Metropolitan Area CCS Project, aims to start operations in 2030.

Shutoken CCS K.K., a company jointly established by INPEX Corp. and Kanto Natural Gas Development Co., will collaborate with Nippon Steel Corp. on the project.

INPEX, one of the largest energy development companies in Japan, is based in Tokyo’s Minato Ward, while Kanto Natural Gas Development is based in Mobara, Chiba Prefecture.

Nippon Steel operates a steel mill in Kimitsu, Chiba Prefecture.

PIPELINE UNDER BOSO PENINSULA

CO₂ emitted from Nippon Steel’s manufacturing base in the Kimitsu area and the Keiyo coastal industrial zone along the Tokyo Bay will be captured after being separated from other gases in the same area.

It will then be transported via a pipeline, which is 73 to 74 centimeters in diameter and buried beneath major roads, to the ocean off Kujukuri town.

There, the carbon dioxide will be injected into underground strata through a special injection well for long-term storage.

While the exact route of the pipeline crossing the Boso Peninsula has yet to be finalized, it is expected to pass through nine cities and towns: Kimitsu, Kisarazu, Sodegaura, Mobara, Oamishirasato, Ichihara, Shirako, Nagara and Kujukuri.

To withstand earthquakes up to a seismic intensity 7 (the maximum on the Japan Meteorological Agency scale), the companies will reinforce necessary parts of the pipeline with mortar, including tunnel interiors.

By the end of the next fiscal year, the basic design work, information sessions for local residents and preliminary discussions are expected to be completed.

The final decision on proceeding with the project will be made in fiscal 2027, with the goal of starting operations in 2030.

The plan is to initially store about 1.2 million tons of CO₂ per year, with a long-term goal of increasing capacity to 5 million tons annually.

CCS PROJECTS ACROSS JAPAN

Japan's ministry of trade and industry considers CCS projects to be key to its strategy to achieve carbon neutrality by 2050.

A pilot CCS project is under way in Tomakomai, Hokkaido. In 2024, the Japan Organization for Metals and Energy Security selected nine projects across the country as Advanced CCS Projects.

The Metropolitan Area CCS Project is among these.

However, during discussions in the Diet, concerns were raised regarding the high cost of the projects, the potential risks of carbon dioxide leakage in the event of a disaster, and doubts about the feasibility of the plan.

Since last autumn, the project operators have been briefing local municipalities, but haven’t announced any details to the public yet.

In an interview with The Asahi Shimbun, the operators said, “We will refrain from media interviews or issuing comments until the resident briefings are completed.”

As a result, residents living along the proposed pipeline route will not be informed of the project details until the scheduled resident briefings are held.

At a briefing held on July 15 for Sodegaura residents, around 30 people were in attendance. According to the attendees, the pipeline route through the city was explained in detail.

Many of the questions raised during the question-and-answer session focused on safety, which the project operators responded to by touting their experience that, “We have been operating a 1,500-kilometer natural gas pipeline for over half a century.”

However, some residents voiced concerns, saying that many participants were unable to understand the workings of the project, because of the abrupt nature of the briefing session.