MIN-GRO · Mineal Nucleation and Growth Kinetics: Generating a general, fundemental model by integrating atomic, macro- and field-scale investigations

Final Activity Report Summary - MIN-GRO (Mineal Nucleation and Growth Kinetics: Generating a general, fundemental model by integrating atomic, macro- and field-scale investigations)

The MIN-GRO RTN brought together research groups located in Germany, France, Spain, Denmark, Norway, Iceland, and the United Kingdom, combining innovative approaches and state-of-the-art instrumentation to better understand crystal nucleation and growth. The results of this project provide basic knowledge to support technological advances in the following areas: CO2 sequestration. Groundwater treatment. Waste management and storage. Enhanced oil recovery from chalk reservoirs. Manufacture of more functional materials for paper, paint, pigment, pharmaceuticals and optical devices. The research also provided clues for understanding bio-mineralisation, a necessary key for medical advances in treatment of osteoporosis and arthritis. The MIN-GRO approach was to investigate carbonate nucleation and growth using a complementary suite of overlapping scale-spanning techniques from atomic scale calculations, atomic-force microscopy, rate measurements in fluid flow and closed system reactors to field-scale studies. Molecular dynamics simulation results obtained by MIN-GRO ER Devis DI TOMMASO, reveal that the first hydration shell of the hydrated magnesium ion consists of six water molecules, whereas in the solvated magnesium bicarbonate and magnesium carbonate complexes the Mg2+ is mostly five-coordinated, which indicates that when coordinated to magnesium the HCO3- and CO32- anions reduce its the coordination sphere aiding the precipitation of carbonate minerals. These results suggest that the major energy barrier to nucleation is the removal of the nearest water shell. Results of these first principle calculations were tested and validated by direct measurement of the nucleation and growth rates of magnesium-bearing carbonate minerals by MIN-GRO ER Juan Diego RODRIGUEZ BLANCO. The first steps of dolomite (MgCa(CO3)2) nucleation and growth was followed via synchrotron-based in situ and time-resolved Energy Dispersive X-ray Diffraction (ED-XRD). In accord with the molecular dynamics calculations, dolomite nucleated via an amorphous calcium-magnesium carbonate phase, its growth kinetics were consistent with first order kinetics rate laws, and activation energies were low. Results of the experimental characterisation of carbonate nucleation and growth rates have been applied to a number of industrial and societal problems. For example, MIN-GRO ESR Alex GYSI measured calcite, dolomite, and magnesite growth rates to design methods to precipitate carbonate minerals from the interaction of basalt with CO2-rich water. These results demonstrate the capacity of using basalt - fluid interaction to store CO2 as carbonate mineral in the subsurface, a novel and potentially very effective method to sequester CO2 from the atmosphere. These results are currently being used in the industrial scale CARB-FIX project to test this possibility on the industrial scale.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз