Controlling hydrogen production from water-reactive aluminum

A method of controlling hydrogen production from water-reactive aluminum, the method comprising:

• immersing a retainer in water held in a primary volume, the retainer defining a secondary volume having an elongate shape and containing a plurality of discrete objects including an activated form of aluminum;
• moving a portion of the water from the primary volume into the secondary volume via permeability of the retainer;
• along the elongate shape of the secondary volume, reacting the portion of the water with the activated form of aluminum to form hydrogen and heat;
• and
• flowing heat and hydrogen from the secondary volume into a remaining portion of the water in the primary volume, wherein a mass ratio of the portion of the water to the activated form of aluminum in the secondary volume is 2:1 along at least a portion of the secondary volume at initiation of the reaction of the water and activated aluminum in the secondary volume.

A system for controlling hydrogen, the system comprising:

• a reaction vessel defining a primary volume;
• a regulator disposed in the primary volume and including a retainer defining a secondary volume in thermal communication with the primary volume, and the secondary volume having an elongate shape;
• a balloon;
• and
• a valve assembly in fluid communication between the balloon and primary volume, the valve assembly including
• a quick-connect valve coupled to the reaction vessel and to the balloon, the quick-connect valve actuatable to release the balloon from the reaction vessel, and
• a check valve disposed in the balloon and operable to move to an open position in response to condensation in the balloon to release at least a portion of the condensation from the balloon while retaining lifting gas within the balloon.