In Eumseong, Republic of Korea, a controlled CO2 release site was designed by Korea CO2 Storage Environmental Management (K-COSEM) Research Center to evaluate properly integrated CO2 monitoring tools at the soil surface. CO2 was released from the 55 m-length PVC-pipe buried at 2.5 m-depth, and then, CO2 concentration and flux were monitored from August 1, 2015 to March 21, 2018 (965 days). Influencing environmental factors such as meteorological data, soil moisture and temperature at 5 different depths were monitored concurrently. The measured soil moisture content decreased rapidly when the soil temperature dropped below 0 °C. When CO2 release began, both surface CO2 flux and soil CO2 concentration increased with a time lag. However, with occurrence of precipitation events, CO2 flux decreased to almost 0 cm3 cm−2 day−1 but soil CO2 concentration increased rapidly. The HYDRUS-SOILCO2 predicted soil moisture, temperature and natural background CO2 flux compared to measured data (R2 = 0.74, 0.89, and 0.85). The 10 scenarios were constructed with different soil characteristic curves. Unlike soil moisture content, the simulated natural CO2 flux did not depend heavily on soil characteristics. The mass of released CO2 was estimated by the difference between the measured CO2 flux data during the release test and natural CO2 prediction model. At the 2nd CO2 release test, there was 1.5 times difference between the actual released CO2 mass and calculated CO2 mass.
Bibliographical noteFunding Information:
The research was supported by the Korea Environmental Industry and Technology Institute (project number: 2018002440003 ), Basic Science Research program through the National Research Foundation of Korea funded by the Ministry of Education (project number: 2016R1D1A1B01008715 ), and the demonstration-scale offshore CO2 storage project in Pohang basin, Republic of Korea, funded from Energy Efficiency & Resources of the Korea Institute of Energy Technology Evaluation and planning (KETEP) (project number: 20162010201980). The simulation input will be available from the public data sharing site such as Zenodo.
All Science Journal Classification (ASJC) codes
- Water Science and Technology