Keywords: electrolysis, steam methane reforming, thermochemical processes, water splitting, hydrogen production, nuclear energy, nuclear power, nuclear hydrogen, gas-cooled nuclear reactors, Japan
Producing hydrogen using nuclear energy
The earliest means of separating hydrogen from water was by electrolysis using electrical energy that usually had been produced by low-efficiency thermodynamic processes. Substitution of thermal energy for electrical energy in high-temperature electrolysis gives a somewhat higher overall efficiency, but significantly complicates the process. Today, the vast majority of hydrogen is produced by steam methane reforming (SMR) followed by a water-shift reaction. A well-designed SMR plant will yield hydrogen having 75?80% of the energy of the methane used. Recent work in Japan has demonstrated the feasibility of substituting high-temperature heat from a gas-cooled nuclear reactor to replace the heat supplied in SMR by the combustion of methane. Using high-temperature heat from nuclear plants to drive thermochemical processes for producing hydrogen has been studied extensively. Bench-scale tests have been carried out in Japan demonstrating the sulphur-iodine (SI) process to produce hydrogen.