An oxygen generator is a device that separates oxygen from the air and produces it at high purity.
It is widely used in various fields such as medical care, industry, and scientific research.
The main operating principle is based on a technology that separates oxygen (approximately 21%) in the air from nitrogen (approximately 78%) and other gases.
The main technologies used for this purpose are Pressure Swing Adsorption (PSA) and Membrane Separation.
Let me now explain each principle in more detail.
Pressure Swing Adsorption (PSA) Method
The PSA method is the most widely used technology in oxygen generators.
It uses an adsorbent to selectively separate oxygen from nitrogen in the air.
The process works as follows:
Air Compression: Ambient air is drawn in through a compressor, which increases the pressure.
During this stage, the air passes through filters that remove dust, moisture, and other contaminants.
Passing Through Adsorption Columns:
The compressed air passes through two or more adsorption columns filled with an adsorbent.
Zeolite is commonly used as the adsorbent, as it has the property of more strongly adsorbing nitrogen.
As the air flows through the columns, nitrogen is captured by the zeolite, while oxygen passes through, effectively separating the two gases.
Pressure Regulation and Regeneration:
While oxygen is being produced in one adsorption column, the other column reduces pressure to release the adsorbed nitrogen.
This cycle is repeated periodically, enabling continuous oxygen production.
Storage and Supply:
The separated oxygen is sent to a storage tank and supplied as needed, typically at a high purity level (90–95% or higher).
The PSA method offers high energy efficiency and stable supply with relatively simple equipment.
It is widely used in hospitals, industrial sites, and aquariums.
Membrane Separation Technology
Membrane separation uses a special semi-permeable membrane to separate gases, operating based on the following principles:
Air Intake and Filtration:
Ambient air is drawn in, and contaminants are removed through filtration.
Passing Through the Membrane:
The air then passes through a semi-permeable membrane that is designed to allow oxygen molecules to pass through faster than nitrogen molecules.
This relies on the differences in molecular size and diffusion rates between oxygen and nitrogen.
Oxygen Collection:
Once oxygen passes through the membrane, it is collected for use, while nitrogen and other gases are discharged.
Compared to the PSA method, membrane separation systems are simpler and easier to maintain.
However, they typically provide lower oxygen purity (around 30–40%), making them less suitable for applications requiring high purity.
This method is mainly used for small-scale oxygen supply or in specific industrial environments.
Other Methods
Cryogenic Distillation
This method involves cooling air to extremely low temperatures to liquefy it, then separating oxygen and nitrogen based on their different boiling points.
It is mainly used for large-scale industrial production and can achieve very high purity levels.
Electrolysis
This method generates oxygen by electrolyzing water and is primarily used in small laboratories or specialized environments.
Industrial Applications
It is used as an essential resource in various industries.
High purity, in particular, is crucial for chemical reactions, combustion, and life support.
Examples of its applications by industry are as follows.
Medical Industry
One of the most important uses in the medical field is the treatment of patients with respiratory diseases or hypoxia.
Oxygen Therapy
For patients suffering from chronic obstructive pulmonary disease (COPD), pneumonia, pulmonary fibrosis, and other breathing difficulties, high-concentration oxygen is supplied through oxygen generators.
This helps increase blood oxygen levels to sustain life or relieve symptoms.
Emergency Medical Care
Oxygen is used in operating rooms, intensive care units, and emergency rooms for anesthesia machines, ventilators, and more.
Home Healthcare
Portable oxygen generators assist patients with chronic illnesses to receive continuous oxygen supply at home.
Steel and Metal Industry
It plays a key role in steel production and metal processing.
Blast Furnace and Steelmaking
It is essential for smelting iron ore in a blast furnace and removing impurities in a Basic Oxygen Furnace (BOF) to produce steel.
It improves combustion efficiency, reduces energy consumption, and increases production speed.
Cutting and Welding
Oxygen is used with acetylene to generate a high-temperature flame for metal cutting and welding.
It is essential in shipbuilding, construction, and the automotive industries.
Chemical Industry
In the chemical industry, it is used as an oxidizer in various chemical reactions.
Oxidation Reactions
It promotes catalytic reactions in the production of key chemicals such as ethylene oxide, ammonia, and methanol.
Wastewater Treatment
It is used in sewage treatment plants to promote microbial respiration, aiding in the decomposition of organic matter.
Aerospace and Military
Aerospace
It is essential for life support of crew members in spacecraft and high-altitude aircraft.
Additionally, it supports combustion as an oxidizer in rocket fuel.
Military
Used for breathing in submarines, fighter jets, and diving equipment, with high purity being essential for special missions.
Environmental and Energy Industry
Combustion Efficiency
It improves efficiency and helps reduce carbon dioxide emissions during the combustion of coal, natural gas, and biomass.
It is especially important in oxy-fuel combustion technology.
Aquariums and Aquaculture
It increases oxygen concentration in water at aquariums and fish farms to ensure the survival of aquatic life.
Other Applications
Food Industry
It is used in Modified Atmosphere Packaging (MAP) to maintain freshness and to promote microbial activity during fermentation processes.
Mining
It is also used in the cyanide leaching process to extract precious metals such as gold and silver from ores.
Sports and Leisure
Portable oxygen cans are used for high-altitude climbing and diving.
Oxygen generators efficiently supply high-purity oxygen using technologies such as PSA, membrane separation, and cryogenic distillation.
Through this, they play an essential role in various industries including medical, steel, chemical, and aerospace sectors.
In this way, oxygen generators enhance industrial efficiency, contribute to environmental protection and life support, and have become a key resource meeting the diverse needs of modern society.
With continuous technological advancements improving the efficiency and accessibility of oxygen generators, their industrial applications will continue to expand in the future.
