Agradecimentos: The authors thanks the São Paulo Research Foundation (FAPESP) for the project funding (grants: #2018/02713-8, #2020/13300-6, and #2021/13068-9), the "Centro Nacional de Processamento de Alto Desempenho em São Paulo" (CENAPAD-SP) and the John David Rogers Computing Center (CCJDR) at the Institute of Physics "Gleb Wataghin" of the University of Campinas for providing computational resources, the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Brasil for Financial Support, and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Brasil. The Article Processing Charge for the publication of this research was funded by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), Brazil (ROR identifier: 00x0ma614) Ver menos

Abstract: Accurate modeling of density and CO2 partitioning in the CO2-water and CO2-brine systems over a wide pressure and temperature range is of high interest in many subsurface processes. We parametrize a new set of CPA and eCPA equations of state accounting for the CO2–H2O cross-association. The CO2-water phase diagrams and the CO2 solubility in NaCl brine are reproduced up to 700 K and 6 m of salinity. The density of CO2 in aqueous mixtures is predicted accurately, including the effect of CO2 dissolution, which may increase or decrease the density depending on conditions. From Monte Carlo simulations, the SPCE-EPM2 force field with optimized unlike parameters reproduces the high-temperature phase diagram without polarization corrections. In this work, our knowledge of the thermodynamics of CO2 in aqueous mixtures is expanded by providing a model for geothermal and CO2 sequestration conditions Ver menos