Air liquefaction, separated according to different gasification points.
The main equipment needed is an air compressor.
Not really, probably.
The critical temperature of oxygen is 154.58K (i.e. -118.57°C), and the critical pressure is 5.043MPa, so the manufacture of liquid oxygen must be at a lower than critical temperature and a higher than critical pressure.
Oxygen industrial production method Industrial large-scale production of oxygen is widely used in the liquid air fractionation method. First make the air through the filter to remove dust and other solid impurities, into the compressor compression, and then through the molecular sieve purifier to remove water vapor and carbon dioxide and other impurity gases. Here the molecular sieve allows smaller molecules such as nitrogen and oxygen to pass through, playing the role of screening molecules. Then it is cooled and depressurized, and when the temperature drops to about -170°C, the air starts to be partially liquefied into the distillation tower, which is fractionated according to the different boiling points of each gas in the air. The boiling point of liquid oxygen is higher than that of liquid nitrogen, and both are easier to vaporize compared to liquid nitrogen. After multi-step fractional distillation can get more than 99% of pure oxygen, and at the same time get nitrogen and extraction of rare gases raw materials. This method is complex. If you need to use the purity of oxygen is not high, the molecular sieve adsorption method can be used to separate the air, the production of oxygen. Specific molecular sieve adsorption capacity of nitrogen than oxygen, when the air through the molecular sieve bed, the outflow of gas containing oxygen is higher, after repeated adsorption can be obtained containing oxygen 70 ~ 80% of the gas. This method is room temperature operation, short cycle, easy to realize automation. In addition, such as the need for high-purity oxygen, can be produced by electrolysis of water, this method of high cost, only suitable for small-scale production. Oxygen separated from the air, generally pressurized storage in sky blue cylinders for industrial, medical or other uses.