Methods for industrial production of oxygen

Separation of liquid air.

Since air contains approximately 21% of oxygen, it is the best cheap and easily available raw material for industrial production of oxygen.

Industry production of oxygen uses the method of separating liquid air: pressurizing the air under low temperature conditions, converting the air into liquid air, and then evaporating. Since liquid nitrogen has a lower boiling point than liquid oxygen, the nitrogen evaporates first from the liquid air, leaving mostly liquid oxygen.

Because any liquid substance has a certain boiling point, people take advantage of this property of the substance to pressurize the air at low temperatures to convert the air into a liquid state and then evaporate. Since the boiling point of nitrogen is -196°C, which is lower than liquid oxygen (-183°C), nitrogen evaporates first from the liquid air, and the remainder is mainly liquid oxygen.

In order to facilitate storage, transportation and use, oxygen is usually pressurized to 15000kPa and stored in blue-painted steel cylinders.

Extended information:

Industrial Oxygen Concentrator

RDO oxygen concentrator air separation mainly consists of two adsorption towers filled with molecular sieves. Under normal temperature conditions , the compressed air enters the adsorption tower after purification treatment such as filtration, dehydration and drying. In the adsorption tower, the nitrogen in the air is adsorbed by the molecular sieve.

The oxygen is enriched in the gas phase, flows out from the outlet and is stored in an oxygen buffer tank, while the molecular sieve that has completed adsorption in another tower is rapidly depressurized to analyze the adsorbed components. By circulating the towers alternately, cheap oxygen with a purity of ≥90 can be obtained. The automatic switching of valves in the entire system is automatically controlled by a computer.

Reference: Baidu Encyclopedia Liquid Air Separation Method

Reference: Baidu Encyclopedia Industrial Oxygen Concentrator