Fundamental Studies on CO2 Sequestration of Concrete Slurry Water Using Supercritical CO2

To prevent drastic climate change due to global warming, it is necessary to transition to a carbon-neutral society by reducing greenhouse gas emissions in all industrial sectors. This study aims to prepare measures to reduce the greenhouse gas in the cement industry, which is a large source of greenhouse gas emissions. The research uses supercritical CO2 carbonation to develop a carbon utilization fixation technology that uses concrete slurry water generated via concrete production as a new CO2 fixation source. Experiments were conducted using this concrete slurry water and supernatant water under different conditions of temperature (40 and 80 degrees C), pressure (100 and 150 bar), and reaction time (10 and 30 min). The results showed that reaction for 10 min was sufficient for complete carbonation at a sludge solids content of 5%. However, reaction products of supernatant water could not be identified due to the presence of Ca(HCO3)(2) as an aqueous solution, warranting further research.

Automated summary

To prevent drastic climate change, it is necessary to reduce greenhouse gas emissions in all industrial sectors. This study focuses on measures to reduce greenhouse gas emissions in the cement industry, using a carbon utilization fixation technology that utilizes concrete slurry water. The results showed promising carbonation reactions, but further research is needed to identify reaction products in the supernatant water.