Abstract:

Implementation of CO2 capture and sequestration has currently been proposed as an effective way to reduce CO2 emissions and alleviate greenhouse effect.CO2 mineral sequestration is the most secure and stable way among all the geological storage types and basalt has been identified as a potential host formation.Moreover, the process of rock dissolution is the basis of mineral precipitation and CO2 mineral sequestration.Therefore, it is necessary to study the dissolution rate of basalt.Previous researches concentrate on rate models for individual primary minerals in basalts under buffer solution.In this paper, we propose a dissolution rate model of basalt in supercritical CO2 solution under different temperatures.The basalt samples used in the experiments were taken from Linqu County, Shandong Province.The laboratory experiments were conducted under a range of temperatures (45-100 ℃) and 10 MPa.The related parameters in the model were calculated through least square method.Model verification were conducted using the model predicted value and experimental value under 57 ℃, 72 ℃, 92 ℃, respectively. Results show that the model is accurate and reliable, which can be directly applied for calculating basalt dissolution rate under CO2 geological sequestration conditions.

Key words: CO₂ mineral sequestration, dissolution rate model, basalt, supercritical CO2, Linqu County, Shandong Province