Hi, A new paper has been published in the Journal of CO₂ Utilization. The study proposes a method for measuring CO₂ fixed in cementitious materials by dissolving them in acid and measuring the released gas using an IR sensor (TOC). The authors organize the challenges related to pre-treatment conditions and gas generation conditions, and present a method that achieves appropriate accuracy.

They note that for carbonated cement pastes, the presence of silica gel may inhibit the acid dissolution of calcium carbonate, so attention must be paid to particle size and the appropriate volume of solution. They also point out that the gas release duration varies depending on the degree of carbonation and hydration, which means that using an instrument designed for another purpose and fully automated may cause issues.

Since the method allows relatively simple measurement, and in principle can accommodate large-volume samples by adjusting the sensor sensitivity via changing the connected bottle volume, I believe this investigation is an interesting contribution.

R. Kurihara, L. Cheng, R. Igami, Z. Wang, A. Aili, K. Noto, M. Tanaka, H. Takahashi, I. Maruyama, Application of acid digestion-based total inorganic carbon measurement for carbonated cement-based materials, J. CO2 Util. 102 (2025) 103266.