In materials science, liquefaction [1] is a process that generates a liquid from a solid or a gas [2] or that generates a non-liquid phase which behaves in accordance with fluid dynamics. [3] It occurs both naturally and artificially. As an example of the latter, a "major commercial application of liquefaction is the liquefaction of air to allow separation of the constituents, such as oxygen, nitrogen, and the noble gases." [4] Another is the conversion of solid coal into a liquid form usable as a substitute for liquid fuels. [5]
In geology, soil liquefaction refers to the process by which water-saturated, unconsolidated sediments are transformed into a substance that acts like a liquid, often in an earthquake. [6] Soil liquefaction was blamed for building collapses in the city of Palu, Indonesia in October 2018. [7]
In a related phenomenon, liquefaction of bulk materials in cargo ships may cause a dangerous shift in the load. [8] [9]
In physics and chemistry, the phase transitions from solid and [gas to liquid (melting and condensation, respectively) may be referred to as liquefaction. The melting point (sometimes called liquefaction point) is the temperature and pressure at which a solid becomes a liquid. In commercial and industrial situations, the process of condensing a gas to liquid is sometimes referred to as liquefaction of gases. Coal liquefaction is the production of liquid fuels from coal using a variety of industrial processes.
Liquefaction is also used in commercial and industrial settings to refer to mechanical dissolution of a solid by mixing, grinding or blending with a liquid. In kitchen or laboratory settings, solids may be chopped into smaller parts sometimes in combination with a liquid, for example in food preparation or laboratory use. This may be done with a blender.
In biology, liquefaction often involves organic tissue turning into a more liquid-like state. For example, liquefactive necrosis in pathology, [10] or liquefaction as a parameter in semen analysis. [11]
[by] a process of liquefaction is meant any process the effect of which is to cause a solid or gaseous body to assume or pass into the liquid state.