Air contains oxygen. Is there any way to filter out other gases and impurities?
The adsorption capacity of specific molecular sieve to nitrogen is greater than that of oxygen. When air passes through the molecular sieve bed, the oxygen content of the outflow gas is higher, and the gas containing 70 to 80% oxygen can be obtained by repeated adsorption. This method is operated at normal temperature with short cycle cycle and easy automation.In addition, high purity oxygen can be produced by electrolysis water. This method has high cost and is only suitable for small-scale production.Oxygen separated from the air is normally stored under pressure in a sky blue cylinder for use in industry, medical care, or other aspects.
Then cooling and depressurization, when the temperature dropped to about 170 degrees Celsius, the air began to partially liquefied into the distillation tower, according to different gases in the boiling point of fractionation. The boiling point of Liquid Oxygen is higher than the boiling point of liquid nitrogen, which is more easily gasified than liquid nitrogen. More than 99% pure oxygen can be obtained by multi-step fractionation, and nitrogen gas and raw materials for extracting rare gas can be obtained simultaneously.This method is complicated. If oxygen is not of high purity, the air can be separated by molecular sieve adsorption to obtain oxygen.
Liquid oxygen fractionation is widely used in large-scale industrial production of oxygen.First of all, 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 impurities gas. Here, the molecular sieve allows nitrogen, oxygen and other smaller molecules to pass through to play the role of screening molecules.
