All medical oxygen is extracted from atmospheric air. Air consists of approximately 21% oxygen, 78% nitrogen, and 1% rare gases such as argon and carbon dioxide. The core of oxygen production is to extract oxygen from the air and purify it to meet medical purity standards (≥90%). There are two primary air separation technologies: cryogenic separation and pressure swing adsorption (PSA) with molecular sieves.
Principles of Cryogenic Separation
This process uses air as the raw material. The air is compressed, purified and liquefied via heat exchange. Liquefied air is mainly a mixture of liquid oxygen and liquid nitrogen. Leveraging their different boiling points, oxygen and nitrogen are separated through rectification. Oxygen produced by cryogenic separation is industrial oxygen, which requires further purification, sterilization and other processes before it can be used as medical oxygen.
(Schematic Diagram of Cryogenic Separation)
Principles of Pressure Swing Adsorption (PSA) with Molecular Sieves
At room temperature, compressed air is filtered and purified. Special oxygen-generating molecular sieves are used to selectively adsorb nitrogen in the air, producing high-purity oxygen (93%±3). PSA stands for Pressure Swing Adsorption.
Key Differences Between Cryogenic Separation and PSA
The two methods differ most significantly in working principles and product form. The cryogenic process liquefies air at extremely low temperatures and separates gases by rectification based on boiling point differences. It produces liquid oxygen, and the initial output is industrial oxygen that needs additional purification for medical use. By contrast, PSA operates at room temperature. It relies on molecular sieves to adsorb nitrogen and generates gaseous oxygen that can be directly applied for medical purposes.
From the supply chain perspective, cryogenic separation relies on external delivery of liquid oxygen. Any disruption to the supply chain will jeopardize oxygen supply in hospitals. PSA enables on-site oxygen production, which is independent, controllable and free from external influences.
In terms of safety, liquid oxygen tanks for cryogenic systems carry leakage risks. One liter of liquid oxygen vaporizes into gaseous oxygen with 800 times its original volume. A leak will create large oxygen-enriched areas, which may easily trigger fires when exposed to ignition sources. In addition, hydrocarbons like acetylene continuously accumulate in the main cold box of cryogenic equipment, posing explosion hazards. PSA runs at normal temperature and low pressure, and its molecular sieves can adsorb most acetylene and hydrocarbons, delivering inherent safety advantages.
Lianbang Medical has specialized in oxygen generation and supply for 29 years and is a national Specialized, Refined, Unique and Innovative "Little Giant" Enterprise. The company boasts profound expertise in molecular sieve PSA oxygen generation technology.
Core Technological Advantages
Lianbang Medical adopts self-developed low-pressure oil-free oxygen generation technology, which cuts energy consumption by over 40% compared with traditional processes and greatly reduces equipment maintenance costs. The intelligent control system supports remote management and real-time monitoring.
Our low-pressure oil-free molecular sieve oxygen generation systems serve a wide range of scenarios:
• For hospitals: Providing main or backup oxygen supply solutions for Grade A Class II and Grade A Class III hospitals.
• For plateau regions: Alleviating hypoxia with micro-pressure and diffused oxygen supply systems.
• For home use: The Yanglianbang series household micro-pressure oxygen chambers bring professional medical oxygen therapy technology into domestic health preservation.