CO2 Mineralization potential in mafic and ultramafic rocks in Central Italy

Reduction of CO2 emissions is crucial for achieving sustainability goals and to do that, concrete methods of long-term carbon storage should be employed. The most common way is geological storage, in which CO2 is kept in underground formation to ensure that it is out of the atmosphere on geological time scales. Among all the solutions, mineralization is the one of the secure techniques that converts CO2 into solid carbonate minerals. This method is particularly appropriate solution since the final product is not a buoyant liquid that must be pumped back into underground formations. This thesis deep dives into the process of mineralization, its working principles, and the feasibility of its application in Central Italy. It summarizes the main chemistry (what leads to the reactions and how quickly they take place), the contribution of the water-rock interactions and the fractures, and the primary methods of conducting the process in situ. Lessons from international projects are used to set realistic expectations for reaction rates, monitoring, and containment. The review then looks, in general terms, the environment of Central Italy where reactive mafic and ultramafic rocks exists. It discusses the impact of their mineralogy and texture on the potential storage capacity along with the role of structural and petrophysical properties in controlling injectivity and carbonate precipitation. According to the discussions, it becomes quite obvious that there are both strong points, involving a large number of reactive minerals and high-quality subsurface data, and practical issues such as non-uniformity of fracture connectivity, high demand to water in dissolved-CO2 approaches, geochemical spikes early in time, and the complexity of monitoring fractured media. In the last part of this thesis, simple screening logic is provided which explains the connection between mineral capacity and fracture-mediated access, as well as design pointers to keep reactions off the wellbore and toward storage-beneficial volumes. This thesis concludes that CO2 mineralization seems to be an effective, sustainable complement to the emission reductions, and a plausible route, supported by the experience of the world community and the local experimentation, for the case of Central Italy.