Sol-Gel Materials for Carbon Mineral Sequestration

Abstract

Sol-gel technology was used to design a new, energetically efficient and economically viable CO2 sequestration technology. Calcium silicate grains were embedded into an inorganic silica matrix. These composites were used for the mineral sequestration of CO2; that is, for permanent carbon fixation. It was found that the mineral grains presented better carbonation efficiency when embedded into an inorganic porous silica matrix. The reaction by-products were calcite particles of a few microns and silica particles of a few tenths of nanometres in size. They could be recycled as raw materials for commercial processes, such as coatings and mortar, for example, depending on their morphology, purity, and particle size and on calculations of the total cost scenarios. Finally, sol-gel composites can also be tailored to capture other atmospheric gases, not just CO2, favouring the viability of this technology.