The new device quickly and easily measures greenhouse gases captured in building materials

The new device can measure carbon dioxide captured in concrete more simply and in a third of the time than current methods. Scientists from the University of Tokyo collaborated with industrial engineers to create a box-like device called a “concrete thermogravimetry and gas analyzer.”

The device heats concrete samples to a temperature of almost 1000°C, causing the release of CO₂ in the middle to be released so that it can be measured. The work is published in Journal of advanced concrete technology.

Compared to the current technique, which involves a time-consuming and complicated process of crushing concrete samples into powder for sampling, this new method is simpler, more accurate and user-friendly.

Scientists hope this will contribute to CO₂ trade in the future as the concrete and cement industry works to offset its emissions under global greenhouse gas management targets.

Concrete is everywhere. We live in it, walk around it, even make films and write songs about it. This strong and durable material, ubiquitous in modern life and even in ancient Rome, is the basis of construction projects around the world. But it’s a mixed bag.

On the one hand, the process of producing concrete and one of its key ingredients, cement, emits a significant amount of greenhouse gases. It is estimated that 5–8% of all CO₂ Emissions caused by human activities so far come exclusively from cement production. On the other hand, concrete can now be used to store CO2₂through carbon capture, utilization and storage methods.

Achieving “net zero”, in which the amount of CO₂ removed from the atmosphere is equal to the amount released, it has become a cornerstone of international policy to combat global warming. To do this, however, we need to know what causes greenhouse gases to be produced and in what concentration, and how much of them can be removed using various techniques.

So far I have not been able to find out how much CO₂ was successfully captured in concrete, it was an extensive process. A cylinder block approximately 10 centimeters in diameter and 20 centimeters high would be crushed in such a way that it could not react with the air (which would affect the results). Then there was a complicated and long process of transforming it into a fine, uniform powder, from which a small sample was taken for chemical analysis.

The new device, developed by researchers at the University of Tokyo in collaboration with industry engineers, can skip this time-consuming process. “We have developed a new machine that can measure the amount of CO₂ it is fixed in the concrete or cementitious material without having to crush it,” said Professor Ippei Maruyama from the Department of Architecture, Graduate School of Engineering, University of Tokyo.

“Until now, there was no simple method for measuring the amount of CO₂ mounted in concrete, but thanks to this device we can shorten the CO measurement time₂ and increase measurement accuracy.”

The specimen block is placed inside the device and then heated to a temperature of 980°C. As the block heats up, gases are released, including CO₂ are released from the block, which can then be measured. This new process takes about a third of the time of current methods, reducing the time it takes for the concrete to react with the air. The results showed that accurate measurement could be performed even when CO₂ was not evenly distributed within the block.

Scientists from the University of Tokyo developed the concept and parts required for the device, and then engineers from Rigaku Corp. they developed them. This was then verified by scientists from the University of Tokyo and Taiheiyo Consultants Co., Ltd.

“This device requires sufficient space and special safety considerations, so for now there are some limitations in its use,” Maruyama said. “However, after further testing, we hope to make this device commercially available so that it can contribute to sound carbon trading in the concrete sector and support global efforts to achieve carbon neutrality.”