Evaluation of CO₂ sorption capacity of granite for CO ₂ geological sequestration

Anthropogenic effects on climate can be mitigated through various measures. Among them being CO₂ sequestration into geological reservoirs including deep saline aquifers, depleted oil/gas reservoirs and coal seams are interested in a powerful means for drastically reducing emissions of CO ₂. When CO₂ would be injected into geological reservoir, it should be necessary to know the potential of CO₂ storing into the reservoir. In this study, amount of CO₂ sorption of granite was to evaluate experimentally at temperatures 50, 70, 100 and 200°C and pressure up to 20 MPa using a magnetic suspension balance (MSB), which allows to measure under supercritical condition. As a result, we confirmed that the granite have the potential of CO₂ sorption. Sorption isotherms obtained from the MSB experiment showed that amount of CO₂ sorption increased with the increasing pressure and decreased with the increasing temperature for all experimental conditions. Especially, amount of CO₂ sorption at 50°C compared with that at other temperatures (70, 100 and 200°C) increased rapidly in the vicinity of the critical state. In addition, the granite showed a maximum of CO₂ sorption into granite could reach up to about 1.0% by weight at 50°C and 14.4MPa. The present results may provide a fundamental knowledge for the development of CO₂ geological sequestration technology.