Air Separation/Liquefaction Systems for Aircraft and Portable Applications
Creare has developed a number of advanced technologies to meet the needs of aircraft and portable gas separation applications including Onboard Oxygen Generating Systems (OBOGS) and Onboard Inert Gas (i.e., nitrogen) Generating Systems (OBIGGS) for military and commercial aircraft. On aircraft, nitrogen is used for fuel tank inerting, and oxygen for emergency breathing, aeromedical use, and special operations missions requiring oxygen prebreathing. Small, lightweight oxygen- and nitrogen-generating systems are also needed for mobile hospitals, home oxygen therapy (HOT), and remote equipment servicing uses. These applications often have unique constraints and requirements.
Our technological approaches span a broad spectrum and include cryogenic separation, molecular sieves, semipermeable membranes, ceramic membranes, and proton exchange membranes. Several of these technologies are described below.
Cryogenic Separation Systems
Creare’s cryogenic separation systems extract high-purity oxygen (99+%) and nitrogen (99+%) from aircraft engine bleed air using advanced, compact cryogenic distillation technology. Cryogenic cooling is provided by a reverse-Brayton cryocooler. The systems produce liquid oxygen and liquid nitrogen for storage and gaseous nitrogen for distribution directly to the aircraft fuel tanks. We have developed large-scale systems for military aircraft application and miniaturized systems for HOT that are based on the production and use of low-pressure liquid, rather than high-pressure gaseous oxygen.
Semipermeable Membrane Separation Systems
Creare’s semipermeable membrane-based OBIGGS combines advanced technology with novel turbomachinery and heat exchangers to provide a lightweight, low-power aircraft fuel tank inerting system.
Molecular Sieve Separation Systems
Creare has developed molecular sieve based oxygen generating systems that combine the advantages of a molecular sieve with the advantages of liquid oxygen storage. In applications that have high peak and low off-peak flow requirements, this hybrid approach allows for a very significant reduction in the size of the system. The molecular sieve and its resource requirements can be much smaller than would be required to meet the peak flow requirements. The peak demand requirements can then be met by the stored liquid oxygen.