Effects of Layer-Charge Distribution of 2:1 Clay Minerals on Methane Hydrate Formation: A Molecular Dynamics Simulation Study

• DOI: 10.1021/acs.langmuir.0c00183
• Publication Date: 2020-02-28T17:23:15Z
• Authors: Yun Li; Meng Chen; Chanjuan Liu; Hongzhe Song; Peng Yuan; Baifa Zhang; Dong Liu; Peixin Du
• Keywords: Clathrate hydrate; Methane gas

Molecular dynamics simulations were used to investigate the effects of external surface a 2:1 clay mineral with different charge amounts and locations on CH4 hydrate formation. The results showed that 512, 51262, 51263, 51264 formed away from surface. high- low-charge layers was occupied by Na+ form various distributions outer- inner-sphere hydration structures, respectively. adsorbed high-charge layer reduced H2O activity disturbing hydrogen bond network, resulting in low tetrahedral arrangement molecules near surface, which inhibited However, more onto vacancy Si-O rings neutral-charge semicage structures. Thus, order parameter this indicated resulted optimal structure for formation than negatively charged Different nucleation mechanisms surfaces models observed. For minerals (i.e., high charge), homogeneous occurred layer, could nucleate either bulk-like solution homogeneously or at mineral-H2O interface heterogeneously.