Oxygen concentrators-also known as home-use molecular sieve oxygen generators or portable oxygen concentrators-fundamentally operate on the principle of Pressure Swing Adsorption (PSA). Using ambient air as the raw material and requiring no chemical additives, these devices-when powered on at room temperature-utilize molecular sieves to adsorb nitrogen and other gases, thereby separating and extracting oxygen with a purity of 93% ± 3% from the air. Based on their maximum oxygen output flow rate per minute, these devices are categorized into 1L, 3L, 5L, and 10L models.
In 1886, the Brin brothers developed the Brin process for oxygen production and introduced the first industrialized air separation oxygen generator. By the early 20th century, cryogenic distillation oxygen generators had become the mainstream equipment for industrial oxygen production. During this same period, portable oxygen concentrators experienced a brief resurgence. In the mid-to-late 20th century, the launch of the Med-Ox Duo Par-a dual-function oxygen generator-marked the inception of the trend toward the miniaturization and consumerization of oxygen concentrators. In 1956, Hangyang Group Co., Ltd. (formerly the Zhejiang Iron Works) successfully developed China's first complete set of air separation equipment capable of producing 30 m³ of oxygen per hour. By 1975, small-scale PSA oxygen units were being widely adopted in hospitals. In 1984, Kratz and Sircar filed a patent for a home-use medical oxygen concentrator. In 1993, the American Society for Testing and Materials (ASTM) issued standard specification F1464-1993 for medical oxygen concentrators. In 1996, the International Organization for Standardization (ISO) published ISO 8359:1996, a safety standard for medical oxygen concentrators. In 1998, China introduced its first industry standard for medical oxygen concentrators: YY/T 0298-1998, "General Technical Specifications for Medical Molecular Sieve Oxygen Generating Equipment." Between 2014 and 2021, China's annual output of oxygen concentrators surged from 197,600 units to 4.16 million units.
Oxygen concentrator technology centers primarily on Pressure Swing Adsorption (PSA), Vacuum Pressure Swing Adsorption (VPSA), and intelligent control systems. Product development is currently iterating toward greater portability and energy efficiency, with applications extending across the medical and healthcare sectors (specifically home oxygen therapy), industrial production (such as metal processing), and the fields of new energy and environmental protection.
