Oxygen Production Process: From Air to Life

Oxygen, essential for life and fundamental in various industries, is one of the most demanded gases in sectors such as health, metallurgy, chemistry and energy. Although it is present in the air at 21%, its industrial production requires a technically advanced process to guarantee its purity, safety and availability. In this note, we will explore the key stages of the oxygen production process, highlighting its importance in critical applications and its impact on industrial and human development.

1. Raw Material: Air

Atmospheric air is the primary source of oxygen, composed of:

Nitrogen (78%)
Oxygen (21%)
Other gases (1%) such as argon, carbon dioxide and traces of noble gases.

The abundance of oxygen in the air makes it a sustainable and accessible resource for industrial extraction.

2. Air Filtration and Purification

Before oxygen is separated, the air is purified to remove particulate matter, moisture and carbon dioxide that could interfere with subsequent stages. This process includes:

Mechanical Filtration: Removes dust, dirt and large particles.
Air drying: Use desiccants or refrigeration to remove moisture.
CO₂ removal: Molecular sieves or chemical absorbents are used.

The result is clean, dry air, suitable for the separation process.

3. Air Compression and Cooling

The purified air is compressed to high pressure using state-of-the-art compressors. It is then progressively cooled in a heat exchanger to reach temperatures close to -200°C, where the gases present in the air are liquefied.

This controlled cooling is a critical step for cryogenic separation, the most widely used method for large-scale oxygen production.

4. Cryogenic Separation

Cryogenic separation is the most efficient process for the production of liquid and gaseous oxygen in large volumes. It consists of:

Air Liquefaction: As air cools, the main components (nitrogen, oxygen and argon) liquefy at different temperatures.
Fractional Distillation: The liquefied air is introduced into a cryogenic distillation tower where it is separated based on the boiling points of its components:
- Nitrogen (-196°C) separates first.
- Oxygen (-183°C) is collected as the main component.
- Argon (-186°C) is separated as a by-product.

This method guarantees oxygen purity of up to 99.5%, suitable for industrial and medical applications.

5. Alternative Production: Oxygen Generators

For smaller scale applications or in remote locations, oxygen generators based on:

Pressure Swing Adsorption (PSA): Compressed air passes through molecular sieves that retain nitrogen, releasing oxygen with a purity of 90-95%.
Separation membranes: They use porous fibers to filter nitrogen and allow oxygen to pass through.

These technologies are ideal for hospitals, small industrial plants and emergency processes.

6. Compression and Storage

The oxygen produced is compressed to facilitate its transport and storage. Depending on its state, it is stored in the following ways:

Compressed gas: In steel cylinders at pressures of 150-200 bars.
Cryogenic liquid: In thermally insulated cryogenic tanks at temperatures of -183°C.

Safe storage is essential to preserve oxygen quality and ensure its availability in critical applications.

7. Transport

Oxygen transport depends on its physical state and the volume required:

Portable cylinders: For small quantities and local applications.
Cryogenic tankers: For long-distance transport in liquid form.
Industrial pipes: For continuous supplies in industrial facilities.

Each method complies with strict safety regulations to ensure product integrity.

8. Applications of Oxygen

Industrially produced oxygen has a wide range of applications, including:

Medical sector: Respiratory therapies, surgery and blood bank storage.
Metallurgy: Cutting, welding and casting of metals.
Water treatment: Oxidation of contaminants and improvement of water quality.
Chemical industry: Production of ethylene oxide, nitric acid and other compounds.
Aeronautics and space: Life support in space suits and vehicles.

Commitment to Sustainability

Oxygen production is evolving towards more sustainable practices, with a focus on:

Energy efficiency: Improving cryogenic and PSA separation processes to reduce energy consumption.
Emissions minimization: Utilization of by-products such as nitrogen and argon for industrial applications.
Use of renewable energy: Powering production plants with solar and wind sources.

These initiatives reinforce the industry's commitment to a cleaner and more responsible future.

Conclusion

The oxygen production process is an example of how science and technology transform a natural resource into an essential input for health, industry and sustainable development. Each stage, from air separation to storage and distribution, is designed to guarantee an efficient, safe and high-quality product.

At Acciomate Engineering & Projects , we offer engineering and project services that optimize each stage of this process, helping companies improve their competitiveness and sustainability.