Measurement report: Method for evaluating CO 2 emissions from a cement plant using atmospheric δ (O 2  ∕ N 2 ) and CO 2 measurements and its implication for future detection of CO 2 capture signals

作者：Shigeyuki Ishidoya, Kazuhiro Tsuboi, Hiroaki Kondo, Kentaro Ishijima, Nobuyuki Aoki, Hidekazu Matsueda, Kazuyuki Saitô · 发表于：Atmospheric chemistry and physics · 年份：2024 · DOI：10.5194/acp-24-1059-2024 · 被引用次数：8 · 研究领域：Atmospheric and Environmental Gas Dynamics、Atmospheric chemistry and aerosols、Atmospheric Ozone and Climate

Abstract. Continuous observations of atmospheric δ(O2/N2) and CO2 amount fractions have been carried out at Ryori (RYO), Japan, since August 2017. In these observations, the O2 : CO2 exchange ratio (ER, -Δy(O2)Δy(CO2)-1) has frequently been lower than expected from short-term variations in emissions from terrestrial biospheric activities and combustion of liquid, gas, and solid fuels. This finding suggests a substantial effect of CO2 emissions from a cement plant located about 6 km northwest of RYO. To evaluate this effect quantitatively, we simulated CO2 amount fractions in the area around RYO by using a fine-scale atmospheric transport model that incorporated CO2 fluxes from terrestrial biospheric activities, fossil fuel combustion, and cement production. The simulated CO2 amount fractions were converted to O2 amount fractions by using the respective ER values of 1.1, 1.4, and 0 for the terrestrial biospheric activities, fossil fuel combustion, and cement production. Thus obtained O2 and CO2 amount fraction changes were used to derive a simulated ER for comparison with the observed ER. To extract the contribution of CO2 emissions from the cement plant, we used y(CO2∗) as an indicator variable, where y(CO2∗) is a conservative variable for terrestrial biospheric activities and fossil fuel combustion obtained by simultaneous analysis of observed δ(O2/N2) and CO2 amount fractions and simulated ERs. We confirmed that the observed and simulated ER values and also the y(CO2∗) valu...