CO2 mineralization feedstock types

Carbon dioxide (CO2) mineralization is a promising carbon capture and storage technology that converts CO2 into stable carbonate minerals. This study provides a comprehensive review of the various feedstock types that can be used for CO2 mineralization. Feedstocks can be divided into two main categories: geologically derived materials and industrial waste products. Geologically derived feedstocks with high carbon sequestration capacity include kimberlite, serpentinite, wollastonite skarns, olivine, and mined alkaline rocks. Industrial waste products like steel slag and mine tailings are also effective feedstocks. CO2 mineralization leverages natural mineral weathering reactions between CO2 and metal oxides/silicates in the feedstocks to form thermodynamically stable carbonates. Key factors affecting feedstock reactivity and carbonation efficiency include mineralogical composition, metal cation presence, porosity, and surface area. This study also outlines the primary carbon mineralization processes, specifically in situ and ex situ mineralization. In situ mineralization involves underground CO2 injection while ex situ is an aboveground process requiring feedstock pretreatment. The environmental, economic, and technological advantages of CO2 mineralization using the diverse feedstock types are presented, highlighting permanent CO2 storage, waste utilization, improved products, and scalability. However, challenges remain regarding reaction kinetics, energy use, and process costs. Ongoing research and innovation to address these limitations is vital to advance CO2 mineralization as an impactful carbon capture and storage solution. This chapter provides important insights into optimal feedstock selection and pretreatment methods to enhance the efficiency, sustainability, and commercial viability of CO2 mineralization technology.