NOVELTY - A hydrogen generator comprises hydrogen membrane reactor having combustion chamber and reaction chamber. The reaction chamber includes a reaction zone and a hydrogen exhaust zone. The reaction zone comprises reaction channels creating a fluid path through the reaction zone. The hydrogen exhaust zone comprises hydrogen exhaust channels creating a fluid path through the hydrogen exhaust zone.    USE - For use with fuel cells.    ADVANTAGE - The inventive hydrogen generator needs only minor modification that can be used to generate hydrogen from being ammonia or hydrocarbon fuels. It includes hydrogen membrane reactor that is small, efficient, and has excellent heat and mass transfer rates, and can operate at relatively low reaction temperature. It incorporates highly active catalyst having rapid residence times and excellent heat transfer abilities with respect to the reactor. It includes heat exchangers that have very high transfer rates, and efficient insulation that minimizes reactor and heat exchanger heat loss in the environment.    DETAILED DESCRIPTION - A hydrogen generator comprises a hydrogen membrane reactor having a combustion chamber (13b) and a reaction chamber (13a), fuel supply (14) or supplies, first and second fuel supply line, oxygen supply (16), oxygen supply line, tail gas supply line, combustion by-product line, and reaction product line. The combustion chamber is in a fluid connection with and a heat exchange-relationship with the reaction chamber. The reaction chamber includes a reaction zone and a hydrogen exhaust zone. The combustion chamber comprises combustion channels creating a fluid path through the combustion chamber. The reaction zone comprises reaction channels creating a fluid path through the reaction zone. The hydrogen exhaust zone comprises hydrogen exhaust channels creating a fluid path through the hydrogen exhaust zone. The first fuel supply line transports fuel from the fuel supply to the reaction chamber. The oxygen supply line transports oxygen from the oxygen supply to the combustion chamber. The second fuel supply line transports fuel from the fuel supply to the combustion chamber. The tail gas supply line transports tail gases from the reaction chamber. The combustion by-product line transports combustion by-products from the combustion chamber. The reaction product line transports hydrogen from the reaction chamber.    An INDEPENDENT CLAIM is also included for a method for generating hydrogen, comprising flowing a supplemental fuel into the combustion chamber at the combustion catalyst light off temperature, where the combustion of the supplemental fuel generates first combustion product gases; replacing the flowing supplemental fuel into the combustion chamber with a combustible fuel at approximately a time when the temperature of the combustion catalyst reaches the combustion catalyst light-off temperature and continuing combustion to enable the temperature of the reaction catalyst to reach the reaction catalyst light off temperature, where the combustion of the combustible fuel generating second combustion by-product gases; flowing a hydrogen-producing fuel in the reaction zone to contact the reaction catalyst at the reaction catalyst light off temperature to produce a reaction zone hydrogen gas mixture comprising hydrogen gas and reaction tail gases; separating the hydrogen gas from the reaction zone hydrogen gas mixture through the hydrogen separation membrane, the hydrogen gas accumulated into the exhaust zone of the reactor chamber; and collecting the hydrogen gas from the exhaust zone of the reaction chamber.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the primary components of the hydrogen generator in the invention.    Hydrogen membrane chamber (12)    Reaction chamber (13a)    Combustion chamber (13b)    Fuel supply (14)    Pre-regeneration chamber (15)    Oxygen supply (16)    Water tank (19)    Heat exchanger (28)    Oxygen heat exchanger (30)    Second fuel supply (54)    Supplemental fuel supply (55)    Adsorbent supply (80)    Ammonia adsorbent supply (81)