Titche et al. (2026): A systematic comparison of calcium carbonate quantification techniques for the monitoring of carbon dioxide removal via lime carbonation direct air capture
Aimee Titche, Olivia Hawrot, Jack Shield, James S Campbell and Phil Renforth, IN: Cambridge Prisms: Carbon Technologies, https://doi.org/10.1017/cct.2026.6
Lime carbonation direct air capture (DAC) systems remove atmospheric carbon dioxide (CO₂) by carbonating calcium hydroxide (Ca(OH)₂) to produce calcium carbonate (CaCO₃), which can release CO₂ for durable storage. Accurate and precise measurement of generated CaCO₃ is essential in quantifying CO₂ removed from the atmosphere, and for optimizing the carbonation process. Methods for measurement of carbonate content are well established, but have yet to be applied to materials produced by this system (i.e. almost solely Ca(OH)₂ and CaCO₃). Five carbonate content analysis techniques (loss on ignition, LOI; thermogravimetric analysis, TGA; combustion analysis of carbon via infrared absorption, CAC-IR; volumetric calcimetry; and quantitative fourier transform infrared spectroscopy, FTIR) were investigated for their measurement accuracy and precision over a range of carbonate contents.