Hydrogen is produced from a hydrocarbon fuel such as diesel, the process comprising: subjecting a mixture of the fuel with oxygen gas to plasma treatment in a dielectric barrier plasma reactor to generate oxygenated molecules; mixing the resulting oxygenated molecules with steam and subjecting them to steam reforming in a compact catalytic reactor at elevated temperature, and then to a water gas shift reaction (possibly with additional steam) at an elevated temperature. The resulting gases may then be mixed with a small quantity of oxygen gas, and subjected to selective oxidation to convert any carbon monoxide to carbon dioxide. This process avoids diluting the gases with nitrogen from the atmosphere, and can achieve very high yields. The hydrogen may be subsequently used in a fuel cell to generate electricity. Such a process may be used at an offshore facility.