Oxygen removal systems during fuel cell shutdown

A purging system for removing oxygen from a fuel cell system during a shutdown period for the fuel cell system, the purging system comprising:

• a separator having an inlet and an outlet;
• a first line for communicating a first gas stream into the separator inlet, the first gas stream including oxygen at a first oxygen molar volume and nitrogen a first nitrogen molar volume;
• a storage device for storing gas, the storage device having an inlet and an outlet;
• a second line for communicating a second gas stream to the storage device inlet for storing the second gas in the storage tank for use in purging the fuel cell system during the shutdown period, the second gas stream including oxygen at a second oxygen molar volume and nitrogen at a second nitrogen molar volume;
• and
• a third line for communicating the stored second gas stream to an inlet of the fuel cell system for delivering the second gas stream to the fuel cell system during the shutdown period,
• the separator removing oxygen from the first exhaust gas stream such that the first nitrogen molar volume is lower than the second nitrogen molar volume and the first oxygen molar volume is higher than the second oxygen molar volume during the shutdown period.