Producing industrial and medical oxygen, is one of the core applications of zeolite molecular sieves. It selectively adsorbs nitrogen molecules through a precise pore structure, thereby efficiently separating high purity oxygen to meet medical, industrial and household needs.
Molecular Sieve Method Oxygen Production Process
Pressure swing adsorption (PSA): Compressed air passes through a molecular sieve bed. During pressurization, the molecular sieve adsorbs nitrogen, enriching oxygen for output. During depressurization, the nitrogen is released, regenerating the molecular sieve.
Vacuum pressure swing adsorption (VPSA): Under pressurization, air enters the adsorption tower, where the molecular sieve selectively adsorbs nitrogen, enriching the oxygen for output. Then switch to vacuum, to desorb nitrogen and regenerate molecular sieve.
Vacuum swing adsorption (VSA): At normal pressure or low pressure, air enters the adsorption tower, nitrogen is preferentially adsorbed by the molecular sieve, and oxygen flows out. Under vacuum, the adsorbed nitrogen is released and the molecular sieve is regenerated.
Cryogenic air separation: Compress the air to a liquid state and separate through distillation process. Nitrogen vaporizes first due to its lower boiling point, while oxygen accumulates in a liquid state for output. Molecular sieves are used for air pretreatment to remove moisture and carbon dioxide.
Applications Of Different Oxygen Production Process
PSA is suitable for portable or medical oxygen production, and small or medium sized industrial oxygen production, the oxygen purity is 90%~95%.
VPSA is suitable for large scale industrial oxygen production, maintaining a stable oxygen concentration above 93%.
VSA is suitable for medium scale continuous oxygen production (large hospital, aquaculture, industrial boilers etc.), the oxygen concentration is 90%~95%.
Cryo-separation offers outstanding large scale production capacity and produces the highest oxygen purity (typically greater than 99.6%), meeting the cutting-edge needs of semiconductors, aerospace. It is widely used in the steel, chemical, electronics, and metallurgical industries.
Zeolite Molecular Sieves For Oxygen Production
Type 5A zeolite molecular sieve: It adsorb small molecules such as nitrogen and carbon dioxide, but has a low adsorption capacity for oxygen. This type of molecular sieve was commonly used in early PSA oxygen production systems.
Type 13X zeolite molecular sieve: It is mainly used for air pretreatment in oxygen production, rather than directly in the core adsorption process for separating oxygen and nitrogen. It has a large adsorption capacity, particularly for moisture, carbon dioxide, and sulfides.
Type LiX zeolite molecular sieve: A modified version of X-type molecular sieve (a variant of 13X), with higher nitrogen selectivity and faster adsorption and desorption rates, it is currently the highest-performing molecular sieve for oxygen production.