強度を損なうことなく二酸化炭素をコンクリート中に貯蔵するプロセス(Process stores carbon dioxide in concrete without strength loss)

2024-06-26 ノースウェスタン大学

＜関連情報＞

• https://news.northwestern.edu/stories/2024/06/simple-new-process-stores-co2-in-concrete-without-compromising-strength/
• https://www.nature.com/articles/s43246-024-00546-9

セメントを懸濁液中で炭酸化することにより、コンクリートを強化しながら二酸化炭素を貯蔵する Storing CO2 while strengthening concrete by carbonating its cement in suspension

Xiaoxu Fu,Alexandre Guerini,Davide Zampini & Alessandro F. Rotta Loria
Communications Materials  Published:26 June 2024
DOI:https://doi.org/10.1038/s43246-024-00546-9

Abstract

Cement is a key constituent of concrete and offers a large sequestration potential of carbon dioxide (CO₂). However, current concrete carbonation approaches are hindered by low CO₂ capture efficiency and high energy consumption, often resulting in weakened concrete. Here, we conceptually develop and experimentally explore a carbonation approach that resorts to injecting CO₂ into a cement suspension subsequently used to manufacture concrete, turning the carbonation reaction into an aqueous ionic reaction with a very fast kinetics compared to traditional diffusion-controlled approaches. This approach achieves a CO₂ sequestration efficiency of up to 45% and maintains an uncompromised concrete strength. The study shows that the CO₂ injection rate influences the polymorph selectivity of mineralized calcium carbonate (CaCO₃) depending on the local environmental conditions and impacts the strength of concrete. The technological simplicity of the proposed approach enables a reduced carbon footprint and promising prospects for industrial implementation.