Visitors can see a liquid that efficiently absorbs CO2 and a new type of CO2 capture system (DAC) that utilises cryogenic temperatures below -160°C.
At the exhibition booth in the Carbon Recycle Factory RITE* facility at the Expo site, we will be conducting tests to capture CO2 from the atmosphere using the unique CO2 absorption liquid and low-temperature equipment.
See how the recovered CO2 is turned into dry ice at low temperatures!
*Research Institute of Innovative Technology for the Earth
Capturing CO2 from the atmosphere is extremely difficult
Means of removing CO2 from the atmosphere include burying it underground or converting it into other substances. Both methods require high purity CO2.
Although the atmospheric concentration of CO2 is rising, the current level is approximately 400 ppm (400 parts per million). In other words, out of every 10,000 molecules in the atmosphere there are only 4 CO2 molecules. Finding, separating, and concentrating only 4 molecules out of 10,000 is extremely difficult.
Utilising discarded cold energy
To address the challenge of capturing CO2 from the air, we focused on the ‘cold energy’ (low temperature) of liquefied natural gas (LNG). Japan imports 75 million tonnes of LNG annually. LNG is normally transported to receiving terminals as a liquid at approximately -160°C and then converted back to gas. Much of the cold energy generated in this process is dumped into the sea, but if this energy is used to cool a container containing the gaseous CO2, the CO2 gradually transforms into dry ice (a solid) resulting in the pressure inside the container dropping.
Using this principle, if the container containing the CO2 -absorbing liquid is depressurised using the cold energy of LNG, the CO2 will be ejected from the CO2 -absorbing liquid and can be collected as dry ice.
