climate change<\/a>.<\/p>\nCement has a high environmental burden<\/h3>\n Direct air capture (DAC) pulls carbon dioxide from the air via physical processes or chemicals.<\/p>\n
The International Energy Agency include the use of DAC technologies as part of their net zero emissions scenario.<\/p>\n
According to the IEA, in 2022, industry was responsible for a quarter of global energy system carbon dioxide emissions.<\/p>\n
After water, cement is the second-most widely used industrial product, and it comes with a high environmental impact.<\/p>\n
Professor Ippei Maruyama from the Department of Architecture at the University of Tokyo Graduate School of Engineering, said: \u201cAs much as 800 kilograms of CO2 is emitted per ton of cement during its production, so reducing emissions has become a significant issue in the concrete industry.<\/p>\n
\u201cConcrete has long been known to react with CO2 in the air to form calcium carbonate, an undesirable phenomenon because it induces corrosion of the steel bars inside concrete structures. However, the concrete industry is now considering ways to make effective use of this reaction.\u201d<\/p>\n
Verifying carbon capture in concrete<\/h3>\n The reaction causes calcium carbonate to trap CO2, removing the gas from the atmosphere. In addition to this, calcium carbonate is found naturally in rocks such as limestone, which are used in concrete manufacturing.<\/p>\n
\u201cThis makes it difficult to distinguish whether or not CO2 identified in concrete has been freshly extracted from the air or comes from rocks,\u201d said Maruyama.<\/p>\n
\u201cSo we developed a method to verify this, which could be used to determine whether the concrete produced can be certified as offsetting CO2 emissions.\u201d<\/p>\n
The team\u2019s method<\/h3>\n The team hydrated cement pastes samples as a concrete replica. They then ground the paste into powder, keeping the non-exposed powder contained and leaving the exposed powder open to the air.<\/p>\n
The team dissolved the powder in acid to collect the gas after a number of days. They then used a technique called accelerator mass spectrometry to analyse the ratio of several carbon isotopes, in particular, carbon-12, carbon-13, and carbon-14.<\/p>\n
This allowed the team to analyse whether the carbon came from carbon capture or was already present in the raw materials. This is because the carbon ratios reflected the known proportion of carbon isotopes in the air at the time the gas was sealed.<\/p>\n
Applying the method to real-world scenarios<\/h3>\n The team now want to apply the carbon capture in cement verification method to real-world scenarios to test how the varied quantities of raw materials used in local concrete production may affect results.<\/p>\n
\u201cFixing carbon dioxide from the air is certified as an act of offsetting CO2 emissions, so it is economically valuable in terms of emissions trading. Digging up calcium carbonate for use in concrete is not, so the distinction is very important, and this research can help to support a healthy market,\u201d concluded Maruyama.<\/p>\n
\u201cWe believe that the carbon neutrality and a circular economy in the construction industry are essential to our future, particularly in Japan where this industry has a role in supporting business continuity and recovery from natural disasters.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"
Researchers from the University of Tokyo and Nagoya University in Japan have developed a method to confirm carbon capture in concrete.<\/p>\n","protected":false},"author":18,"featured_media":40499,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[24433],"tags":[24536],"acf":[],"yoast_head":"\n
Verifying carbon capture in concrete<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n \n \n \n \n \n\t \n\t \n\t \n