An investigation of the global uptake of CO2 by lime from 1930 to 2020

Abstract. A substantial amount of CO2 is released into the

atmosphere from the process of the high-temperature decomposition of

limestone to produce lime. However, during the lifecycle of lime

production, the alkaline components of lime will continuously absorb

CO2 from the atmosphere during use and waste disposal. Here, we adopt

an analytical model describing the carbonation process to obtain regional

and global estimates of carbon uptake from 1930 to 2020 using lime lifecycle

use-based material data. The results reveal that the global uptake of

CO2 by lime increased from 9.16 Mt C yr−1 (95 % confidence

interval, CI: 1.84–18.76 Mt C) in 1930 to 34.84 Mt C yr−1 (95 %

CI: 23.50–49.81 Mt C) in 2020. Cumulatively, approximately 1444.70 Mt C

(95 % CI: 1016.24–1961.05 Mt C) was sequestered by lime produced between

1930 and 2020, corresponding to 38.83 % of the process emissions during

the same period, mainly contributed from the utilization stage (76.21 % of

the total uptake). We also fitted the missing lime output data of China from

1930 to 2001, thus compensating for the lack of China's lime production

(cumulative 7023.30 Mt) and underestimation of its carbon uptake (467.85 Mt C) in the international data. Since 1930, lime-based materials in China have

accounted for the largest proportion (about 63.95 %) of the global total.

Our results provide data to support including lime carbon uptake into global

carbon budgets and scientific proof for further research of the potential of

lime-containing materials in carbon capture and storage. The data utilized

in the present study can be accessed at

https://doi.org/10.5281/zenodo.7896106 (Ma et al., 2023).