Research Progress on CO2 Capture, Utilization, and Storage of Fly Ash

Abstract

The research progress of different technologies of fly ash for CO2 capture, utilization, and storage at home and abroad was summarized, and the research opportunities were discussed. Fly ash could mineralize, capture, and store CO2 through direct dry, semi dry, wet, and indirect methods, reducing the leaching of heavy metals in fly ash while mineralizing CO2. The mineralized fly ash was more suitable for making concrete additives because it could effectively reduce the content of free CaO and MgO. Fly ash could also be made into activated carbon, zeolite, porous silica, and other products for physical adsorption and capture of CO2. The type of products depended mainly on the composition and physical/chemical properties of fly ash. In terms of CO2 utilization, fly ash could not only expand the utilization of building materials but also be made as catalysts or catalyst carriers required for various chemical processes of CO2 and new materials such as pseudo boehmite. The proposal of "double carbon" in China and the physical/chemical characteristics of fly ash from coal-fired power plants provide a new method for comprehensive utilization of fly ash.