RT Journal Article T1 Three-phase equilibria of CO2 hydrate from computer simulation in presence of NaCl A1 Borrero, Antonio A1 Díaz Acosta, Antonio A1 Blazquez, Samuel A1 Zerón, Iván M. A1 Algaba Fernández, Jesús A1 Conde, María M. A1 Jiménez Blas, Felipe AB In this work, the cryoscopic decrease effect, as a function of the NaCl concentration, on the carbon dioxide (CO2) hydrate dissociation line conditions was determined through molecular dynamic simulations. In particular, we have determined the three-phase (solid hydrate–aqueous phase–liquid CO2) coexistence temperature at 100, 400, and 1000 bar at several initial NaCl concentrations in the aqueous phase, from 0.0 to 3.0 m, using the direct-coexistence technique. We used the well-known TIP4P/2005 and TraPPe force fields for water and CO2 molecules, respectively. Also, the water–salt interactions were described using the Madrid-2019 force field, which has been specifically developed for various salts in combination with the TIP4P/2005 water model. According to the results obtained in this work, the dissociation temperature of the CO2 hydrate decreases when the NaCl concentration in the initial aqueous phase increases. The results obtained are in excellent agreement with the experimental data reported in the literature. We have also observed how the dynamics of melting and growth of the CO2 hydrate becomes slower when the NaCl concentration is increased. As a consequence, longer simulation times (on the order of dozens of microseconds) are necessary when the NaCl concentration increases. Finally, we have also analyzed finite-size effects on the three-phase coexistence temperature of these systems by performing simulations at 400 bar with two different system sizes at two different NaCl concentrations (0.0 and 3.0 m). Non-negligible deviations have been found between the results obtained from the two system sizes. PB American Chemical Society SN 0887-0624 SN 1520-5029 (electrónico) YR 2025 FD 2025 LK https://hdl.handle.net/10272/28197 UL https://hdl.handle.net/10272/28197 LA eng NO Borrero, A., Díaz-Acosta, A., Blazquez, S., Zerón, I. M., Algaba, J., Conde, M. M., & Blas, F. J. (2025). Three-Phase Equilibria of CO2 Hydrate from Computer Simulation in the Presence of NaCl. Energy & Fuels, 39(11), 5522–5533. https://doi.org/10.1021/acs.energyfuels.5c00174 NO The authors extend their heartfelt appreciation to Dr. E. Dendy Sloan for his invaluable contributions to the study of gas hydrates. His groundbreaking work has been instrumental in advancing experimental research while also paving the way for molecular simulations, offering deeper insights into hydrate structure and behavior. His legacy remains a guiding force in both theoretical and applied research, inspiring future generations of scientists. We are profoundly grateful for his unwavering dedication and the enduring influence of his work in academia and industry. This work was funded by Ministerio de Ciencia e Innovación (Grant Nos. PID2021-125081NB-I00 and PID2022-136919NB-C32), Junta de Andalucía (P20-00363), and Universidad de Huelva (P.O. FEDER UHU-1255522, FEDER-UHU-202034, and EPIT1282023), the first four were cofinanced by EU FEDER funds. We greatly acknowledge RES resources at Picasso provided by The Supercomputing and Bioinnovation Center of the University of Malaga to FI-2024-1-0017. S.B. acknowledges Ayuntamiento de Madrid for a Residencia de Estudiantes grant. The authors gratefully acknowledge the Universidad Politecnica de Madrid (www.upm.es) for providing computing resources on Magerit Supercomputer. NO Funding for open access charge: Universidad de Huelva / CBUA DS Repositorio Institucional de la Universidad de Huelva RD 31 may 2026