Wed, 17 March, 2021
GEOPRO partner, The University of Cologne, talk about their ongoing research in the project
Understanding the physical and chemical properties of superhot geothermal fluids is a challenging task. This is caused, among other things, by the difficulties associated with the measurement of thermodynamic properties such as mineral solubilities and equilibrium constants at high temperature and pressure conditions. In addition, existing thermodynamic models that are used, e.g., for describing the density and chemical composition of geothermal fluids, are often not applicable under superhot conditions.
We predict geothermal fluid properties as a function of temperature and pressure using a computational chemistry approach on the atomic scale. For this purpose, we perform molecular dynamics simulations, in which the movement of ions and molecules in aqueous solutions is sampled in real time. In conjunction with advanced free energy methods, we can obtain, e.g., the equilibrium constants of dissociation reactions.
So far, our simulations have confirmed the linear relationship between NaCl dissociation constant and fluid density, which is known from experiments. Such simple correlations constitute useful ingredients for the development of new thermodynamic models that are strongly demanded by geothermal industry.