- There are several technologies available for generating air enriched in oxygen, including air separation by fractional distillation, electrolysis and pressure swing adsorption.
- From these methods pressure swing adsorption has the lowest infrastructure cost and complexity and was selected for the generation of oxygen in a patient care scenario (10 – 60 l/min).
Pressure Swing Adsorption
- In Pressure Swing Adsorption (PSA), pressurised air is fed to a column loaded with zeolite. The Zeolite is a microporous material, which selectively captures the nitrogen from the airstream and oxygen enriched air leaves the column. As soon as the Zeolite is saturated with nitrogen, the column is vented to release the nitrogen. Then the column is ready for a second cycle, and in switched (loading/venting) operation can produce a quasi-continuous stream of oxygen enriched air.
- The technology does not consume any material (other than air), and has a low energy demand (pressurised air (ca. 6 bar) and electricity to switch valves).
- Depending on operation mode, system size and zeolite choice, Pressure Swing Adsorption is capable of generating oxygen enriched air with oxygen contents higher than 90% and with flow rates exceeding 10 l / min.
- There is an existing industry for the manufacturing of oxygen generators using pressure swing adsorption, e.g. Inmatec, in various scales from single patient units to industrial scale apparatus. However, these manufacturers may not be able to cover the current demand, and DYI solutions may help to treat patients suffering from COVID-19 induced pneumonia.
- The oxygen generator instructions given on this site are the work of a group of engineers to enable the access to oxygen enriched air to as many people and hospital care scenarios as possible.
- We do not sell or commercially manufacture any devices. We only offer education and know-how via this site and instructional videos.
- We can not give any guarantee that a device built by someone else will work or work to a given performance.
Safety and potential hazards
- This technology uses pressurised air (up to 6 bar), which can be hazardous if using large containers.
- The generation of LiX Zeolite from batteries involves hazardous steps and appropriate safety measures are required.
- If using oil-free and toxin free parts and units for the construction of the concentrator, the oxygen enriched air leaving the unit will have the same purity (oil/toxins) as the air fed to the concentrator, but will be enriched in oxygen and depleted in nitrogen and water. It might further be contaminated with dust originating from the Zeolites, and consequently dust filtration and re-humidification are required steps prior to any use of the oxygen enriched air stream.
This is work in progress. Please contribute in the comments. All valuable inputs will help us define the best solution.