Methods and systems for generating hydrogen gas from methane are disclosed. In one embodiment, a method includes heating a vessel containing a catalyst to a temperature above approximately 600.degree. centigrade and pressurizing the vessel to about ten atmospheres. A pressure swing absorbent, a methane stream, and a stream of steam are introduced into the vessel. In a particular aspect, the temperature may be maintained within a range of approximately 600 C. to approximately 700 C.