Solar-based reactor tubes and related systems and methods

A method, comprising:

• using solar power to heat a reactor tube;
• passing a reactant-containing gas through a first region of the heated reactor tube so that a catalyst in the first region of the heated reactor tube catalyzes a reaction of the reactant-containing gas to produce hydrogen;
• passing the hydrogen through a hydrogen-permeable membrane so that the hydrogen enters a second region of the reactor tube which is different from the first region of the reactor tube;
• and
• using a sweep gas to remove the hydrogen from the second region of the reactor tube.

A system, comprising:

• a reactor tube, comprising:
• a first cylinder having an inner surface defining an interior of the first cylinder;
• a second cylinder comprising a hydrogen-permeable membrane disposed within the interior of the first cylinder;
• a catalyst;
• and
• a heating element
• wherein:
• the reactor tube has an annular space between an interior surface of the first cylinder and an exterior surface of the second cylinder;
• and
• the reactor tube has an inner space defined by an interior surface of the second cylinder.