Hydrogen generator and process for generating hydrogen for supplying a fuel cell

A hydrogen generator is electronically controlled depending on the difference between the actual and target demand for electric power in a vehicle using the hydrogen to generate power in a fuel cell. The generator has a first zone (10) with catalyst chemically reforming a gas mixture and a second zone (12) with devices forming a cold plasma in the gases. The devices are activated when the power generated is less than the power demand. Independent claims are included for the following: (a) Generating hydrogen as above. (b) Apparatus producing hydrogen has a supply stage with storage for reagents connected to a reforming stage including the above generator. Preferred Features: The second zone is upstream of the first zone and has electrodes arranged along it and connected to a high voltage supply to produce the plasma. The plasma is also produced when the first zone is not up to its normal operating temperature. Downstream of the first zone is a zone (16) for oxidising carbon monoxide produced by the reforming.