How Oxygen is produced and stored artificially?

     Oxygen is one of the most abundant elements on earth. Oxygen is a life sustaining element and is used by all the animals to survive. It also has many scientific, commercial and industrial applications. In this article we will learn how oxygen is manufacture artificially.

The most common method to produce oxygen is by cryogenic distillation in which argon and nitrogen is also produce along with oxygen. Cryogenic means something produce or store below -150°C to absolute zero. Let’s understand the whole process by looking at the given diagram.

  1.) First of all, the air is filtered to remove all dust particles and then is sucked inside a compressor.

  2.) In a compressor, there are two valves – inlet valve and discharge valve. Air comes inside through inlet valve and with the piston; it is compressed to a high pressure. As a result, it heats up (potential energy of piston converts to heat energy). This warm air goes to the freezing unit through discharge valve.

  3.) In the freezing unit, cooling effect is done by coil tube in which liquid nitrogen is been fed. Note that nitrogen is not mixed with compressed air but present in coil tube. Now, air becomes cold and its temperature drops by -200°C.

  4.) After that this cool air is sends to the separator in which carbon dioxide is got separated in the form of dry ice.

 5.) After this air goes inside expansion turbine, in which air turns into liquid air with temperature -200°C.

  6.) Now, liquid air goes in the air distillation column, where its warming starts. Air is a mixture of gases. Because of slow warming, different gases separate out. Nitrogen first separates out with boiling temperature of -196°C, below which argon with temperature -186°C and at last liquid oxygen gets collected with temperature -185°C.

    Nitrogen collected used in fertilizers and food processing industry. Argon mainly used in iron and steel industry. Liquid oxygen is collected and filled in cylinders.

    Oxygen Cylinders:

Oxygen stored in cylinders in liquid form and stored at high pressure almost at 200bar. These cylinders come with pressure regulator to regulate and fix the pressure needed. Today patients needed oxygen at lower pressure than 200bar, so from regulator you can fix or lower pressure.

The larger size cylinder that you see mostly, is 1.5 meters tall and contains 7800litres liquid oxygen. Patient admitted to hospital need 130litres/minute. This means that this cylinder in total will last about an hour.

India has lifted liquid oxygen from Singapore and from other countries in cryogenic liquid oxygen tanks, in which oxygen is stored at temperature -182°C or -185°C.