liquidgas

Liquid gas, or liquefied gas, is a term for a gas that has been converted into a liquid. Liquefaction typically involves cooling the gas to its boiling point or applying high pressure, producing a dense, low-temperature liquid that is easier to store and transport. Many industrial gases—such as methane, nitrogen, oxygen, argon, and hydrogen—are routinely liquefied. A common example is liquefied petroleum gas (LPG), a mix of propane and butane stored under pressure as a liquid for heating, cooking, or fueling devices. Liquefied natural gas (LNG) is natural gas cooled to about -162°C to condense it for long-distance transport and use as a fuel.

Production and storage: Liquefaction is done in industrial gas plants. LNG requires cryogenic processing and insulated tanks; LPG is stored in pressurized cylinders. Cryogenic liquids like liquid nitrogen, liquid oxygen, and liquid helium are kept at very low temperatures in specialized dewars for medical, industrial, and research uses. Safety: hazards include flammability, asphyxiation risk, and cold burns; proper ventilation, leak detection, and pressure relief devices are essential.

See also: liquefied natural gas, liquefied petroleum gas, cryogenics, Dewar, boil-off.