describe how one can obtain pure oxygen by fractional distillation of liquedfied air
http://en.wikipedia.org/wiki/Oxygen
To obtain pure oxygen by fractional distillation of liquefied air, you would follow these steps:
1. Compression of Air: The process starts with the compression of atmospheric air to increase its pressure. This compression step is necessary to convert the air into a liquid state at low temperatures.
2. Cooling: The compressed air is then cooled using a series of heat exchangers. The cooling process involves removing heat from the gas, which causes it to condense into a liquid state.
3. Fractional Distillation Column: The liquid air is passed into a fractional distillation column. This column is tall and cylindrical, and it contains several trays or plates. The column is maintained at very low temperatures (-183°C or -297.4°F) to keep the gases in a liquid state.
4. Separation: As the liquid air enters the distillation column, it starts to vaporize due to the temperature gradient along the column. The component gases, such as oxygen, nitrogen, and argon, have different boiling points. Therefore, they vaporize at different heights in the column.
5. Collection: At different heights or stages of the column, the gases are collected in separate trays or plates. The coldest gases condense and collect at the bottom of the column, while the lighter gases move upwards.
6. Purification: After the collection, the obtained oxygen-rich vapor is further purified to remove any remaining impurities or traces of other gases. This purification process ensures that the oxygen is of high purity, suitable for various applications.
7. Storage and Utilization: Finally, the pure oxygen is stored in suitable containers or cylinders under pressure. It can then be utilized for medical purposes, industrial applications, or other relevant uses.
It's important to note that this process requires specialized equipment and expertise due to the extreme temperatures and pressures involved. Hence, it is typically carried out in industrial settings by professionals trained in handling and operating the necessary equipment.