HIGH-TEMPERATURE ELECTROLYSIS (HTE)

High-temperature electrolysis is sometimes called steam electrolysis. It is very similar to water electrolysis. The difference is in the form of provided energy. Some of the energy is brought in the form of electric energy and some in the form of heat. This way, the efficiency of the process is increased. Water and hydrogen enter the electrolyser, forming an enriched mixture (75%hm hydrogen and 25%hm steam). Hydrogen is then dissociated in the condensation unit. The reactions in high-temperature electrolytes are reversed to reactions in solid oxide fuel cells. Energy demands for the process are temperatures between 600 -100°C. In the HTSE process, water is first converted to steam by using nuclear thermal energy rather than electricity, and then dissociated at the cathode to form the hydrogen molecules as well as oxygen ions, which subsequently migrate through the solid oxide electrolyte material, and then form oxygen molecules at the anode surface.[1] 

The overall efficiency can reach up to 45 -50%. The energy demands are lower than conventional electrolysis since the higher the steam temperature, the lower the electricity demand. It is a very clean method of hydrogen production and is constantly under development as one of the candidates for the largescale hydrogen production. Nuclear energy is one of the leading electricity sources.[2]