Storage Potential of CO₂ by Distributed CCS in Japan

Abstract

As one type of the CCS (Carbon Capture and Storage), “distributed CCS” (DCCS), conducted by injection facilities situated dispersively near CO₂ emission sources, has recently attracted attention. This study estimates the storage potential of CO₂ of the DCCS into the aquifer in Japan.
This study assumes three cases of the storage depth of 50m∼400m, 400m∼750m, and 50m∼750m. The calculated CO₂ storage potential ranges from 7.9Gt·CO₂ to 33.6Gt·CO₂, which indicates that the DCCS in Japan can stably control domestic emission of CO₂ to achieve the reduction commitments under the Kyoto Protocol for decades of years.
Under the DCCS, proportion of dissolved CO₂ into formation water to injected CO₂ is higher than that of traditional CCCS (Concentrated CCS). This indicates that, in DCCS, solubility trapping and subsequent mineral trapping of CO₂ would efficiently occurs. Further study would be needed how fast the solubility trapping progresses to mineral trapping.
In DCCS, regional distribution of geothermal gradient would be influential to the estimate of the storage potential of CO₂ Investigation of the geothermal gradient around the injected area would improve accuracy of prediction of the storage potential of CO₂.