Oxygen Production Plant Flow Sheet

oxygen plant

Oxygen ratio in the air on a dry basis is about 20.95 % by volume and 23.20 % in terms of weight. Its boiling point at atmospheric pressure is about 90.2 Kelvin or -182.95 degree centigrade. By the help of Cryogenic technology oxygen from air is separated in pure form. For large scale, oxygen production cryogenic technology is the only method available now.

Oxygen plant is designed based on below equipment:

1. Air compressor: Axial compressor used for building up the air pressure sucking it from the atmosphere through a set of shifting filters.
2. Refrigeration unit: Air is cooled by countercurrent oxygen and waste nitrogen streams.
3. Moisture separator
4. Air purification unit: It consists of adsorbers,  regeneration heater, post filters, nitrogen vent silencer and air vent silencer .
5. Cold box: It is a box enclosed with a main heat exchanger, medium pressure column, low pressure column, expansion turbine, Sub cooler, liquid oxygen circulation pumps, condenser-vaporizer and   Liquid oxygen filters (acetylene adsorbers).
6. Heater
7. Liquid oxygen storage tank
8. Gaseous oxygen storage tank

High production oxygen plants are designed based on the cryogenic system where the air is cooled, condensed, separated and purified and stored as liquid oxygen. Atmospheric air is filtered and compressed to high pressures. Moisture is separated as water and compressed air is passed to silica gel adsorbers. The gas is passed to main heat exchangers and passed to turbines for expansion of gas which results in a temperature drop below the critical temperature and pressure forming liquid mixture and oxygen is collected as liquid oxygen.