Carbon Capture Concrete: Capturing CO2 for a Greener Future

Brief

Discover how innovative Japanese research unlocks the potential of concrete to capture atmospheric CO2, aiding emission reduction and promoting carbon neutrality.

Insight

Japanese researchers from the University of Tokyo and Nagoya University have developed a groundbreaking method to reduce CO2 emissions in concrete manufacturing by sequestering atmospheric CO2.

This technique distinguishes between CO2 originating from raw materials and that captured from the air during the formation of calcium carbonate within concrete. By analyzing specific carbon isotopes, the team confirmed the occurrence of direct air carbon capture (DAC) in concrete, a process vital for industries and countries aiming to cut carbon emissions.

DAC, a crucial component of the International Energy Agency’s net-zero emissions scenario for 2050, involves extracting CO2 from the air through physical or chemical means. With the industrial sector contributing 25% of global energy system CO2 emissions in 2022, and cement being the second most used industrial product after water, reducing emissions in concrete production is essential.

Professor Ippei Maruyama of the University of Tokyo highlights the urgency of emission reduction in the concrete industry, noting that 800 kilograms of CO2 are emitted per ton of cement. Traditionally, the reaction of concrete with atmospheric CO2 to form calcium carbonate was seen negatively due to its corrosion effect on steel reinforcement. However, this reaction is now being reconsidered for its potential in CO2 reduction.

The research involved creating samples of hydrated cement paste, which were then exposed or sealed from air, and analyzing them using accelerator mass spectrometry. This allowed the team to determine the source of CO2 in the concrete. Maruyama emphasized the economic value of this research in emissions trading, as capturing atmospheric CO2 is certified as CO2 offsetting, unlike using naturally occurring calcium carbonate.

The study marks a significant step towards carbon neutrality and a circular economy in construction, especially in Japan, where the construction industry plays a pivotal role in business continuity and disaster recovery.

Highlight

By analyzing specific carbon isotopes, the team confirmed the occurrence of direct air carbon capture (DAC) in concrete, a process vital for industries and countries aiming to cut carbon emissions.
With the industrial sector contributing 25% of global energy system CO2 emissions in 2022, and cement being the second most used industrial product after water, reducing emissions in concrete production is essential.
Professor Ippei Maruyama of the University of Tokyo highlights the urgency of emission reduction in the concrete industry, noting that 800 kilograms of CO2 are emitted per ton of cement