In structure I, the CO 2 hydrate crystallizes as one of two cubic hydrates composed of 46 H 2 O molecules (or D 2 O) and eight CO 2 molecules occupying both large cavities (tetrakaidecahedral) and small cavities (pentagonal dodecahedral). [37]

2024年1月1日 · X-ray diffraction demonstrates formation of Structure I hydrate on SBA-15 C 8. At 7.0 MPa and 248 K, the water-to-hydrate conversion on hydrophobized SBA-15 C 8 reaches 96% as compared to only 71% on a pristine SBA-15 sample with comparable pore size, pore volume and surface area.

structure I hydrate 定 义 单位晶胞为立方体心结构，分子式为6X·2Y·46H2O，分子通式为Gas·5.75 H2O。 应用学科 海洋科技（一级学科），海洋科学（二级学科），海洋地质学、海洋地球物理学、海洋地理学和河口海岸学（三级学科）

Gas hydrates have received considerable attention due to their important role in flow assurance for the oil and gas industry, their extensive natural occurrence on Earth and extraterrestrial...

Structure I (sI) hydrates are the most commonly encountered naturally occurring hydrate structure which encases small diameter molecules (0.40 - 0.55 nm) such as methane or ethane gas. [2] Structures II (sII) and H (sH) hydrates accomodate larger guest molecules, typically propane or iso-butane for sII or combinations of methane gas and ...

2024年4月15日 · Gas hydrates with methane as a guest molecule form structure I hydrates with a unit cell containing 46 water molecules arranged on two small dodecahedral cages and six tetra decahedral large cages. An ideal structure I methane hydrate unit cell contains 8 methane molecules and one in each cage.

2002年8月1日 · As a typical structure I hydrate, ethane hydrate is cubic, Pm3n, with unit cell parameter a=11.956 Å. Ethane molecules (Fig. 1) were found in both large and small cavities. The degree of cage filling of the small cavity was 0.058(5), that of the large cavity was 1.00(1).

2018年6月28日 · Gas hydrates are ice-like, nonstoichiometric, crystalline solids composed of a three-dimensional network of hydrogen-bonded water molecules enclosing gas molecules in defined cavities of different sizes. The (nonpolar) gas molecules in turn prevent the water cages from collapsing (e.g., von Stackelberg 1949, Sloan 1998, and literature within).

2024年1月1日 · X-ray diffraction demonstrates formation of Structure I hydrate on SBA-15 C 8. At 7.0 MPa and 248 K, the water-to-hydrate conversion on hydrophobized SBA-15 C 8 reaches 96% as compared to only 71% on a pristine SBA-15 sample with comparable pore size, pore volume and surface area.

Two main gas hydrate structures are cubic type I and type II. Type I unit cell is 12 A and consists of 2D cages and 6T cages (46 water molecules). Type II unit cell is 17 A and consists of 16D and 8H cages (136 water molecules). Photos of two main gas hydrate structures constructed in Janda Lab from plastic kits: