Gas hydrates in permafrost

Ab Initio Studies of Structural and Mechanical Properties of NH3, NO, and N2O Hydrates

“…Clathrate hydrates are a nonstoichiometric crystal with inclusions that forms at low temperature or high pressure. , Generally, hydrophobic gases can readily form gas hydrates, such as CH 4 and CO 2 . It is well-known that structures of hydrate in nature are type sI, type sII (both cubic), and sH (hexagonal) structure hydrates; the unit crystal cell of sI consists of two small cages (5 12 ) and six large cages (5 12 6 2 ); the unit cell of sII is composed by 16 small cages (5 12 ) and 8 large cages (5 12 6 4 ); and there are 3 (5 12 ) and 2 (4 3 5 6 6 3 ) cages and 1 large cage (5 12 6 8 ) in sH. ,, With the discovery of a large number of undersea clathrate hydrates worldwide in the 1980s and 1990s, clathrate hydrates have become a research hotspot in the field of energy. , As an important resource, methane gas hydrate’s correspondence with global climate change requires thorough inspection on its stability. Therefore, a growing number of investigations on natural gas hydrates (NGHs) have been conducted, and research direction also extends from the prevention of natural gas pipeline blockages , to resource utilization, − gas storage and transportation, geological disasters, , carbon dioxide capture, environmental protection, , and even gas hydrates in space …”

“…1 , 3 , 4 With the discovery of a large number of undersea clathrate hydrates worldwide in the 1980s and 1990s, clathrate hydrates have become a research hotspot in the field of energy. 5 , 6 As an important resource, methane gas hydrate’s correspondence with global climate change requires thorough inspection on its stability. Therefore, a growing number of investigations on natural gas hydrates (NGHs) have been conducted, and research direction also extends from the prevention of natural gas pipeline blockages 7 , 8 to resource utilization, 9 − 11 gas storage and transportation, 12 geological disasters, 13 , 14 carbon dioxide capture, 15 environmental protection, 16 , 17 and even gas hydrates in space.…”