Carbon recycling is the key to Japan’s innovative path to carbon neutrality.
Carbon dioxide is the main cause of global warming. At the Carbon Dioxide Capture and Storage Center in Tomakomai, Japan shows how CO2 can be captured and stored. Experts are confident that technology can play a key role in achieving the goal of zero CO2 net emissions by 2050.
Capture and storage of CO2
“CCS is an acronym for Carbon Dioxide Capture and Storage. It is a technology that aims to prevent global warming by capturing the CO2 generated in industrial activities and CO2 storage underground,” said Nakajima Toshiaki, president of Japan CCS.
The CO2 source is a gas hub at a Tomakomai refinery (Idemitsu Kosan Hokkaido Refinery). The process starts sending a gas containing carbon dioxide to a capture facility.
“We receive a maximum of 25 tons of CO2 per hour, equivalent to 600 tons per day. Our goal was to process 100,000 tons in a year. We reached the 300 thousand tons two years ago,” said Yamagishi Kazuyuki, public relations manager at the Tomakomai Center for Carbon Dioxide Capture and Storage (CCS).
CO2 storage underground
When the gas containing CO2 reaches the center, there is a process that separates the CO2 from the gas. This CO2 is captured by chemical absorption inside three towers. The next step is to store CO2.
“The captured CO2 is sent to the entrance of this well, after having applied a certain pressure. Through this tube, the CO2 is sent to the geological layers below the bottom of the sea”, explained Yamagishi Kazuyuiki, public relations manager of the CCS center.
The two injection wells are drilled towards offshore submarine reservoirs. One of the wells reached a layer of sandstone, situated between 1,000 and 1200 meters deep. The other reached a volcanic layer situated between 2400 to 3000 meters deep.
Japan believes that technology will become a key approach to reducing the impact of global warming after the implementation phase.
“The International Energy Agency estimates that by 2050 it will be necessary to know how to store more than 7 billion tons of CO2 per year with CCS systems to achieve zero net value. This would allow to use fossil fuels cleanerly, or capture CO2 directly from the atmosphere and store it underground,” said Nakajima Toshiaki, president of Japan CCS.
Concrete made from CO2
In addition to the capture and storage of CO2 on the ground, Japan found a way to use CO2 to produce a type of concrete with negative carbon emissions, CO2-SUICOM.
” The conventional concrete emits approximately 288 kilograms of CO2 per cubic meter during production, but the CO2-SUICOM reaches the 18-pound negative”, explained Watanabe Kenzo, Managing Director of the Materials Department of the Kajima Technical Research Institute.
It is the first type of negative concrete at the level of carbon emissions, there is an absorption of CO2 during the cure. The secret of the process is the addition of a special material, a chemical by-product, before the concrete comes into contact with CO2.
“We use CO2 gas instead of water for the CO2-SUICOM healing process. CO2 is immobilized when contacting the concrete while still hardening. We added a special mix “Y C2S”, which we call magic powder, because it solidifies a large amount of CO2. The more we produce this magical concrete, the more we reduce the CO2 of the atmosphere,” added Watanabe Kenzo.
The CO2-SUICOM concrete has been used in various types of construction projects as prefabricated material, namely in the means of a road near the town of Masuda, in Shimane province. Researchers expect technology to be applied to more materials in the future so as to pave the way for less polluting construction processes.