Patent ID: 7025931

Claim:
A system for reducing the amount of oxygen in an oxygen-containing gas within a closed environment, comprising: a source of hydrogen gas; a controllable means for mixing, in response to a control signal, a selected amount of said hydrogen gas with a portion of said oxygen-containing gas from said closed environment to form a first gas mixture that includes hydrogen and oxygen; a catalyst coupled to said controllable means for receiving said first gas mixture, said catalyst causing a reaction between said hydrogen and at least a portion of said oxygen in said first gas mixture wherein a second gas mixture is formed and returned to said closed environment, said second gas mixture (i) having a lower percentage of oxygen than said first gas mixture, and (ii) containing oxygen in an amount sufficient to make said second gas mixture breathable; and at least one oxygen sensor positioned in said closed environment and coupled to said controllable means for generating said control signal when oxygen levels of said oxygen-containing gas in said closed environment reach a threshold level defined for an ambient pressure in said closed environment.