Factors controlling the dawsonite formation in geological CO₂ storage-a sensitivity analysis to the geochemical simulation modeling the Tokyo Bay area-

Abstract

Geological CO₂ storage into deep, saline aquifer becomes important in CCS (Carbon dioxide capture and storage) technology as an effective measure to reduce CO₂ emission into atmosphere. The stored CO₂ is expected to be fixed by carbonates through reactions between CO₂, formation water and reservoir rocks. Because of an environment of saline aquifer in sedimentary strata, dawsonite, or Na-Al hydrous carbonate, is frequently formed in geochemical simulation on geological CO₂ storage. However, its stability in a long period over sociological time scale is not understood well at present. We carried out a sensitivity analysis on the formation of dawsonite to parameters used in the geochemical simulation modeling the underground Tokyo Bay area (Todaka et al., 2009). It is concluded that Al-bearing chemical species are important in the formation of dawsonite in the CO₂ reservoir, in addition to fco₂ pointed out in our previous study.