Abstract

The increasing impact of human activities on the global environment has stirred the deployment of multiple approaches aiming at the decrease of the environmental footprint of these activities, the reduction of greenhouse gases in the atmosphere, and ultimately to mitigate the consequences of global warming and worldwide climate change. In this regard, the geologic CO₂ sequestration (GCS) has been identified as one of the adequate methods to effectively reach these goals. CO₂ can be mineralized and sequestrated in solid forms. Hence, geological structures such as soils, mining residues (tailings) and man-made (industrial) wastes, as well as directly available by-products (cements), have the potential to carbonate many Gt of CO₂ per year. However, there is a technological gap which impairs the real-time monitoring of CO₂ sequestration by GCS processes. This gap has been identified quite early; it is a consequence of the lack of consistent results and methodologies for estimating the CO₂ sequestration and storage capacity. Such a condition seriously hampers the deployment of carbon capture and sequestration (CCS) efforts. For example, the optimization of carbon capture processes requires the very knowledge of the composition of the geological structures. Therefore, the on-site monitoring of the carbon capture and of the factors involved in the carbon sequestration, such as the chemical composition of these structures (elements and minerals), is one of the key capabilities that allow to speed up the development of carbon capture by natural products. The National Research Council Canada (NRC) team has developed analytical methods and prototypes relying on the Laser-Induced Breakdown Spectroscopy (LIBS) technique that appears to be well adapted to fulfill the requirements. The team has worked on the development of the technology for the real-time analysis of geological matrices. In addition, an innovative LIBS approach for the on-site carbon capture assessment in geochemical structures is developed. An accuracy of 0.02% is obtained for the measurement of soil organic carbon in agriculture soils. Moreover, the team devised an integrated LIBS platform to perform automated in-field mineral characterization of rocks. Silicate minerals rich in magnesium and calcium, such as serpentine, are quantified in rocks to evaluate the carbon mineralization rate in waste rocks. In conclusion, this NRC developed approach is able to quantify the carbon content in these structures as well as to characterize and quantify the factors that are involved in the carbon capture process. In this talk, the methods developed, the progress achieved, and the results in the quantification of carbon and the identification of the factors involved in the carbon capture in geochemical matrices (such as soil, mine tailings, concrete and rocks) will be presented.