Molecular dynamics simulation study on the growth of CO2 hydrate from high-concentration NaCl solutions

Abstract

The influences of NaCl concentrations from 1–5 mol% on the growth kinetics of CO₂ hydrates and the structural characteristics of the formed solid products were investigated through molecular dynamics simulations. Lower temperatures and higher NaCl concentrations exhibited increasing inhibition effects on hydrate growth. Small numbers of Cl⁻ anions constituted distorted edge-sharing host cages while minority Na⁺ cations tended to behave as hopping guests shuttling among host cages. NaCl crystallites were observed, suggesting both the carbon storage capability in the hydrate even from highly salty solutions and the presence of solid NaCl inclusions within polycrystalline hydrate entities, necessitating practical considerations in potential industrial processes such as oceanic carbon storage and desalination.