The Environment Ministry plans to promote projects to confine factory-emitted carbon dioxide in layers of porous rock more than 1,000 meters below the ocean floor to help fight global warming.
According to ministry officials, the plan to inject carbon dioxide in the form of compressed “supercritical fluid” into the layers, called aquifers, is in response to a revision made last November to an international treaty on maritime dumping of industrial waste.
The revision to the Convention on the Prevention of Maritime Pollution by Dumping of Wastes and Other Matter, or the London Convention added carbon dioxide to the list of substances that can be disposed of in the oceans under certain conditions.
Under legislation the ministry will submit to the Diet during its current session, businesses would be able to implement projects for storing carbon dioxide in aquifers provided they have the permission of the environment minister.
This condition was attached to prevent businesses from implementing shoddy storage projects that would allow carbon dioxide to escape and contaminate seawater.
The government would be empowered to impose fines of up to 10 million yen for transgressions.
The storage technology involves extracting carbon dioxide from exhaust gases emitted by power generation plants and other industrial plants. The resulting compressed supercritical fluid would then be pumped into the aquifers via pipelines.
Carbon dioxide could also be pumped into the seabed by offshore rigs after it is transported to them by ships.
Scientists believe that water-bearing layers surrounding the Japanese archipelago could retain up to 150 billion tons of carbon dioxide, equivalent to more than 100 years of carbon dioxide emissions by Japanese plants.
The storage technologies are still in the developmental stage in Japan, though the technology to convert carbon dioxide gas into supercritical fluid by applying high pressure is already being used in Norway and some other oil and natural gas producing countries.
The technology was developed from older technology designed to squeeze crude oil out of depleted oil fields by infusing them with carbon dioxide and water.
It is believed that the technology will allow water-bearing layers to retain 99 percent of the carbon dioxide injected in the form of supercritical fluid even after 1,000 years.
The Research Institute of Innovative Technology for the Earth, a Kyoto-based government-backed entity, has been testing the technology in Nagaoka, Niigata Prefecture, in a project subsidized by the Ministry of Economy, Trade and Industry.
The envisioned legislation is designed to provide legal support for the Nagaoka project. It is also aimed at laying the legislative groundwork for the implementation of various storage projects on a commercial basis, the Environment Ministry officials said.
The legislation would oblige operators of carbon dioxide storage businesses to conduct environmental assessments of sea areas and to monitor the areas for any signs of pollution.
The environment minister would have the power to order a halt to storage projects if operators are found implementing shoddy storage work or neglecting their obligation to monitor relevant areas for signs of pollution.
Other businesses planning to conduct offshore drilling would have to file reports with the minister if they plan to operate in areas being used for carbon dioxide storage.