than that of a standard water electrolyzer because the hydrogen re circulated from the cathode to the anode depolarizes the anode resulting in the hydrogen oxidation reaction rather than the oxygen evolution reaction at the anode and thus a lower cell voltage the reactions occurring in subsystem 600 are as follows anode h 2 u2192 2h 2 e u2212 eqn 8 chemical u2014 center chamber 2h 2nahco 3 u2192 2h 2 o 2co 2 2na eqn 9 cathode 2h 2 o 2 e u2212 u2192 h 2 2oh u2212 eqn 10 it should be understood that subsystem 600 may be modified to include certain components to improve operation or to configure the system for certain applications these components include but are not limited to filters heat exchangers additional valves pumps or blowers and process sensors and alarms additionally it should be noted that although fig6 does not show the interactions between process controller 400 and subsystem 600 process controller 400 controls all aspects of the operation of subsystem 600 the following examples are illustrative only and do not limit the present invention an actual embodiment of system 10 was constructed in this embodiment eoc subsystem 200 included a 5 cell stack with an active cell area of 50 cm 2 cell that was operated at a maximum current density of 100 ma sq cm eoc subsystem 200 generated a maximum of 83 cm 3 min of pure o 2 when in oxygen generation mode when in oxygen removal mode eoc subsystem 200 generated a gas stream of lt 1 oxygen subsystem 300 included a 5 cell dmfc stack with an active area of 80 sq cm.