Gas liquefaction plants
Introduction
Liquefaction or liquefaction of gases is the change of state that occurs when a substance goes from a gaseous state to a liquid state, due to an increase in pressure (isothermal compression) and a decrease in temperature (adiabatic expansion), reaching a high overpressure.
History
The liquefaction of gases was discovered by Michael Faraday in 1823, when working with ammonia.
It was discovered by subjecting ammonia to high pressures and low temperatures, thus obtaining the transformation from gas to liquid.
Process
Gas liquefaction includes a series of phases used to convert a gas into a liquid state. The processes are used for scientific, industrial and commercial purposes. Many gases can be put into a liquid state at normal atmospheric pressure by simple refrigeration and others, such as carbon dioxide, require pressurization.
The liquefaction of gases is a complicated process that uses different compressions and expansions to achieve high pressures and very low temperatures, using, for example, turboexpanders.
Uses
Gas liquefaction is used for the analysis of the fundamental properties of gas molecules (intermolecular forces), for the storage of gases, for example: LPG, and in refrigeration and air conditioning. In these, the liquefied gas inside the condenser releases the heat of vaporization, and evaporates in the evaporator, where the heat of vaporization is absorbed. Ammonia was the first of these refrigerants, but it has been replaced by compounds derived from petroleum and halogens.
Liquid oxygen is supplied to hospitals for conversion to gas for patients suffering from respiratory problems, and liquid nitrogen is used in dermatology and in artificial insemination to freeze semen.
The liquefied chlorine is transported for eventual solution in water, after which it is used for water purification, sanitation of industrial waste, sewage and swimming pools, bleaching of paper pulp and textiles and the manufacture of carbon tetrachloride "Carbon (IV) chloride"), glycol and many other organic compounds, as well as phosgene gas, which was used in the First World War in Flanders and in gaseous form in Ypres, Belgium, although the tanks were full of liquid.