A Low-power medical Oxygen Concentrator

An on-board oxygen concentrator is required during long duration manned space missions to supply medical oxygen. The commercial medical oxygen generators based on pressure swing adsorption (PSA) are large and highly power intensive. TDA Research, Inc. is developing a small, lightweight, portable oxygen generator based on a vacuum swing adsorption (VSA) to produce concentrated medical oxygen. The unit uses ambient vehicle cabin air as the feed and delivers high purity oxygen while meeting NASA's requirements for high flow capacity, closed-loop tissue oxygen control and operation in microgravity/partial gravity.

TDA's VSA system uses a modified version of the lithium exchanged low silica X zeolite (Li-LSX), a state-of- the-art air separation sorbent extensively used in commercial Portable Oxygen Concentrators (POCs) to enhance the N2 adsorption capacity. With this sorbent, we are able to design four compact modules which each are capable of generating up to 4 SLPM of medical grade oxygen. One head unit will serve as a manifold to provide a total oxygen delivery rate of 16 SLPM with closed-loop control based on the patient requirements.

Experimental and modeling results of the medical oxygen concentrator will be presented as well as system design concepts.