Supplemental oxygen delivery systems are vital to provide a critical life support respiratory function. Whether they are used for patients suffering from lung diseases or other illnesses, or astronauts donning an oxygen mask during a toxic spill or fire on a spacecraft, lightweight and portable oxygen delivery systems are in high demand. A lightweight portable oxygen concentrator was developed that can produce 1 to 6 lpm of pulse oxygen in a noiseless system that can be worn on the user’s hip or in a shoulder sling.
To concentrate oxygen from air, an electrochemical separation method previously was developed that chemically reacts the oxygen in the air to a water molecule, transports this water molecule through an ion-exchange membrane via diffusion, and subsequently oxidizes the water back to oxygen. This creates a 100% pure oxygen product without having to compress air or use multiple beds that are cycled. By only using a potential driving force to separate selectively oxygen from air, the system is noiseless and has no moving parts.
In theory, oxygen is not pumped through the membrane, but is transported through the membrane as a water molecule. On the cathode side, air is introduced to the cell under ambient conditions where the oxygen is reduced to form water. This water is transported across the ion-exchange membrane via diffusion to the anode where it is oxidized to form oxygen, releasing a proton. This proton migrates through the membrane, back to the cathode, where it reacts with incoming oxygen to produce water, keeping the process going. Of importance is that water is conserved and no other reactants are required for this separation system to function. Only the ambient air and a source of DC energy are required to operate the separator.
There are three major advantages to concentrating oxygen electrochemically:
- An air compressor and valves that actuate between adsorption beds are not needed.
- The electrochemical cell components that provide the separation process are lighter in weight than the ubiquitous zeolite separation beds used in all other separation processes.
- The electrochemical separation process converts oxygen to water, separates it from other constituents, and converts the water back to oxygen, thus producing a 100% pure oxygen stream free from smoke, dust, impurities, nitrogen, and other atmospheric chemical constituents.