clathration

Clathration is a chemical process where molecules of one substance are trapped within the crystal lattice structure of another substance. This occurs when a compound forms cavities, or cages, of a specific size during crystallization. If other molecules present in the solution are small enough to fit into these cavities, they become entrapped, while larger molecules are excluded.12

This phenomenon is utilized in various separation techniques, particularly in the chemical industry for separating components derived from petroleum. A notable example is the formation of clathrate compounds by gases like methane, ethane, and carbon dioxide with water molecules, creating crystalline structures where the gas molecules are enclosed within a water framework. These clathrate hydrates, especially methane hydrates, are found in significant quantities beneath the ocean floor and in permafrost regions.23