Experimental Investigation of Mafic Rocks for Carbon Mineralization Prospect

Abstract

Carbon capture and storage by mineralization (CCSM) in mafic rock is a viable technology to store captured gaseous carbon dioxide (CO 2 ) into carbonate minerals by chemical reaction with rocks. Here, we investigate the interaction of CO 2 with four outcrop mafic rock samples of the Saudi Arabian region for their CCSM potential. Samples interacted with CO 2 at 8.27 MPa and 343 K in a batch reactor system for 2 months, and petrophysical and geomechanical properties were analyzed before and after CO 2 treatment. The results indicate that the initial state of samples is compromised after exposure to CO 2 . X-ray diffaction and scanning electron microscopy analyses confirm the reactivity of CO 2 with samples. Petrophysical and mechanical parameters also changed after interaction with CO 2 ; i.e., porosity decreased, while Young's modulus and hardness increased. The results of this study thus shed light on rapid carbon mineralization in the mafic rocks of Saudi Arabia, which can have direct implications for CO 2 geo-sequestration in the region.

Review on Multiscale CO2 Mineralization and Geological Storage: Mechanisms, Characterization, Modeling, Applications and Perspectives

“…At neutral to high pH under low temperature and oxidizing conditions, groundwater in basalt is enriched with divalent metal cations, such as Ca 2+ and Mg 2+ . CO 3 2– and H + produced by ionization will undergo carbonation and precipitation reactions with silicate minerals in rocks, as shown in eqs –. ,− false( normalCa , normalMg , normalFe false) 2 SiO 4 + 2 CO 3 + 4 H + = 2 false( normalCa , normalMg , normalFe false) CO 3 + SiO 2 + 2 H 2 O Among them, in the process of mineral dissolution, the following processes occur: basaltic glass + x H + → Mg 2 + + Ca 2 + + Fe 2 + · · · Mg 2 SiO 4 + 4 H + = 2 Mg 2 + + 2 …”

“…At neutral to high pH under low temperature and oxidizing conditions, groundwater in basalt is enriched with divalent metal cations, such as Ca 2+ and Mg 2+ . CO 3 2– and H + produced by ionization will undergo carbonation and precipitation reactions with silicate minerals in rocks, as shown in eqs –. ,− Among them, in the process of mineral dissolution, the following processes occur: …”

The Future of CO2 Geological Sequestration: An Overview of Mineralization in Aqueous and Supercritical States

“…This also explains why both CO 2 aqueous solution and scCO 2 experiments try to minimize the particle size, and even use artificial synthesis methods to prepare nanomagnesium olivine crystals for mineralization. , On the other hand, there are many rock minerals available for CO 2 mineralization research, such as basalt, peridotite, , plagioclase, potassium feldspar, basaltic glass, serpentine, olivine, pyroxene, wollastonite and many other minerals, which are all silicate ores rich in Ca 2+ or Mg 2+ . However, the content of Ca 2+ or Mg 2+ varies greatly among them . In the process of geological sequestration, it is crucial to select a suitable site during the process of geological sequestration .…”

Experiments of CO2-Basalt-Fluid Interactions and Micromechanical Alterations: Implications for Carbon Mineralization

“…Understanding the mechanical evolution is of great importance for long-term safety. The existing studies are from the perspective of macroscopic mechanics to study the change in mechanical properties. , However, the diagenetic environment determines the strong heterogeneity of the pore structure of basalt, which contains abundant pores and vesicles. This poses a challenge to the selection of rock samples.…”