Experimental and thermodynamic analysis of the carbonation of geopolymer under geologic CO2 sequestration conditions

The integrity of wellbore sealing is vital for carbon dioxide sequestration. The carbonation of metakaolin-based geopolymer under conditions of 50 °C and 10 MPa was experimentally studied. Furthermore, thermodynamic simulation was utilized to analyze the carbonation of the geopolymer. The experimental results show that unreacted raw materials and granular precursors remain after the hydration of metakaolin-based geopolymer. After 28 days of corrosion, a substantial quantity of sodium aluminosilicate hydrate gel is produced; however, macro-cracks develop on the surface of the sample, resulting in a decrease in strength. Thermodynamic simulation revealed that dawsonite, Clinoptilolite-(K), and Heulandite-(Ca) show excellent resistance to carbon dioxide corrosion. Moreover, an increase in temperature enhances the resistance of mineral phases to carbonation. However, the higher concentration of carbon dioxide in aqueous solution accelerates the rate of mineral corrosion. In the presence of sodium ions and sulfate ions in aqueous solution, Chabazite-(Na) and Stilbite-(K) consume more carbon dioxide during corrosion, leading to increased dawsonite formation. Low-calcium aluminosilicate materials are suitable for developing a corrosion-resistant geopolymer cementing slurry system.