Home > Encyclopedia of Science > Gases, Liquefaction of

• Critical temperature and pressure
• Words to Know
• Methods of liquefaction
• Practical applications

Liquefaction of gases is the process by which a gas is converted to a liquid. For example, oxygen normally occurs as a gas. However, by applying sufficient amounts of pressure and by reducing the temperature by a sufficient amount, oxygen can be converted to a liquid.

Liquefaction is an important process commercially because substances in the liquid state take up much less room than they do in their gaseous state. As an example, oxygen is often used in space vehicles to burn the fuel on which they operate. If the oxygen had to be carried in its gaseous form, a space vehicle would have to be thousands of times larger than anything that could possibly fly....