What is a supercritical gas?
Supercritical gas, more precisely known as a supercritical fluid, is a different state of matter that has the properties of liquid and gas. Supercritical gas can be considered the middle state between liquids and gases. Supercritical gases are created only above the thermodynamic point of the material. This usually means high pressures, often between about 40 and 80 atmospheres, although it is very different. Some critical points, especially water, are up to 218 atmosphere and beyond. Supercritical fluids have low viscosities and high diffuse. Supercritical fluids are found in at least two areas of nature. The first is around the hydrothermal holes and underwater volcanoes on the bottom of the ocean, where the pressure is so large that it is possible to create a supercritical gas. The pressure of 3 km (1.8 mi) underwater is 300 atmosphere, very much. Another natural supercritical gas is the lower atmosphere of Venus, which is very dense and hot on the surface (93 atmosphere, 735 hp). Surprisingly, this means that only two states of mass can be found on the surface: solid and supercritical gas. Conventional liquids and gases do not exist there.
Supercritical fluids have at least a dozen industrial applications. One of them is supercritical fluid extraction, where supercritical fluids are used to extract some material from the surrounding matrix. It is used to extract caffeine from coffee beans. Supercritical carbon dioxide sucks caffeine directly from them. Similarly, supercritical fluids are used in supercritical drying, which extracts liquid from the matrix. This is used in the preparation of biological samples for electron microscopy, as well as Airgel synthesis, a material that holds 12 Guinness World Records for features such as lightness and insulation.
Supercritical water oxidation is used to oxidize hazardous waste, making them safe for disposal. This process is also used to synthesize micro and nanoparticles for various pharmaceutical applications. The opposite of greatCritical fluid extraction is called impregnation, the material is introduced into the matrix rather than removed. The list continues. As you can see, the application of supercritical fluids are numerous.