RT Journal Article
T1 Dissociation line and driving force for nucleation of the multiple occupied hydrogen hydrate from computer simulation
A1 Torrejón, Miguel J.
A1 Blazquez, Samuel
A1 Algaba Fernández, Jesús
A1 Conde, María M.
A1 Jiménez Blas, Felipe
AB In this work, we determine the dissociation temperature of hydrogen (H2) hydrate by computer simulation using two different methods. In both cases, the molecules of water and H2 are modeled using the TIP4P/Ice and a modified version of the Silvera and Goldman models, respectively, and the Berthelot combining rule for the cross water–H2 interactions has been modified. The first method used in this work is the solubility method, which consists of determining the solubility of H2 in an aqueous phase when in contact with the H2 hydrate (H–Lw) phase and when in contact with the pure H2 phase (Lw–LH2) at different temperatures. At a given pressure value, both solubility curves intersect at the temperature (T3) at which the three phases coexist in equilibrium. Following this approach, we determine the dissociation temperature of H2 hydrate at 185 MPa finding a good agreement with the data previously reported in the literature. We also analyze the effect of the multiple occupancy of the D, or small, and H, or large, cages of the sII hydrate structure. We conclude that the T3 value is barely affected by the occupancy of the H2 hydrate at 185 MPa. From the analysis of the solubility curves and performing extra bulk simulations of the three phases involved in the equilibrium, we also determine the driving force for nucleation (ΔμNEC) at 185 MPa as a function of the supercooling degree and the H2 hydrate occupancy. We determine that, thermodynamically, the most favored occupancy of the H2 hydrate consists of 1 H2 molecule in the D cages and 3 in the H cages (i.e., 1–3 occupancy). We also conclude that the double occupancy of the small D cages is not favored because the ΔμNEC values obtained for this occupancy are the most positive ones. The second approach used in this work is the direct coexistence technique using an initial H2 hydrate phase with 1–3 occupancy. We also propose a new modification of the Berthelot combining rule to improve the predictions of the T3 values. Following this method, we determine the T3 at 100, 185, and 300 MPa finding excellent agreement with the experimental data.
PB American Chemical Society
SN 0887-0624
SN 1520-5029 (electrónico)
YR 2025
FD 2025
LK https://hdl.handle.net/10272/28196
UL https://hdl.handle.net/10272/28196
LA eng
NO Miguel J. Torrejón, Samuel Blazquez, Jesús Algaba, Maria M. Conde, and Felipe J. Blas Energy & Fuels 2025 39 (31), 15184-15197 DOI: 10.1021/acs.energyfuels.5c01012
NO The authors wish to express their sincere gratitude to Dr. E. Dendy Sloan for his invaluable contributions to the study of gas hydrates. His pioneering work has not only been fundamental in advancing experimental knowledge of hydrates but has also opened new doors to molecular simulation in this field, enabling a deeper understanding of their structure and behavior. His legacy continues to guide both theoretical and applied research, inspiring future generations of scientists. We deeply appreciate his tireless dedication and the lasting impact of his contributions to both academia and industry. M.J.T., J.A., and F.J.B. acknowledge grant refs (PID2021-125081NBI00 and PID2024-158030NB-I00) financed both by MCIN/ AEI/10.13039/501100011033 and FEDER EU, and Universidad de Huelva (P.O. FEDER EPIT1282023), also cofinanced by EU FEDER funds. S.B. and M.M.C. also acknowledge grant ref PID2022-136919NB-C32 financed by MCIN/AEI/ 10.13039/501100011033 and FEDER EU. M.J.T. acknowledges the research contract (ref 01/2022/38143) of Programa Investigo (Plan de Recuperación, Transformación y Resiliencia, Fondos NextGeneration EU) from Junta de Andalucía (HU/INV/0004/2022). We also greatly acknowledge RES resources provided by the Barcelona Supercomputing Center in Mare Nostrum to FI-2023-3-0011 and by The Supercomputing and Bioinnovation Center of the University of Malaga in Picasso 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 the Magerit Supercomputer.
NO Funding for open access charge: Universidad de Huelva / CBUA
DS Repositorio Institucional de la Universidad de Huelva
RD 30 may 2026