The fuel cell reactions produce electron current by an exchange process. The hydroxyl ions, hydrogen, and electrolyte produce free electrons at the anode, water, and heat.
All oxygen is consumed in the reactor.
Water Water vapor and hydrogen exit the stack, where the water vapor is condensed, and the hydrogen is replenished and recirculated. The heat of condensation is also removed with the fuel cell coolant loop. Hydrogen is not completely consumed in the reaction, but is recirculated for increased efficiency. Water produced from the reaction and water vapor are extracted with a centrifugal water separator. The water is then pressure-fed to the potable water tanks in the lower deck of the crew cabin.