​Hydrogen is already used in many sectors of industry, including chemistry, food processing, glass transformation, iron and steel manufacturing, and microelectronics. Electrolysis also shows promise for use in conversion and storage systems for intermittent renewables.

Today, however, the great majority of hydrogen production processes are based on methane/natural gas reforming. The CEA is developing an alternative process using electrically powered water electrolysis. Using a carbon-free electrical source cuts down on greenhouse gas emissions and saves fossil fuels.

The main difference between the various existing water electrolysis processes is their operating temperature, which determines the quantity of electricity required to separate the water molecule. CEA Liten’s hydrogen production laboratory has just taken a major step forward with its high-temperature (700°C) electrolysis system that produces hydrogen using steam at 150°C and electricity, with electrical consumption of 3.9 kWh/Nm3 (1) of hydrogen. The prototype proves that hydrogen can be produced from low-temperature steam, achieving unrivalled efficiency through optimum use of heat in the system. 

This CEA-designed system comprises a high-performance, cost-efficient cell-stack, which are at the heart of the hydrogen production reaction, together with all the auxiliary components required to manage the fluid, thermal and electrical functions of the system and enable it to operate alone. This compact system, roughly the same size as a refrigerator, can produce between 1 and 2.5 Nm3/h of hydrogen.  Exhaust gas heat is recovered for preheating intake gas using efficient high-temperature heat exchangers when the system is in a slightly exothermal operating mode. The efficiency of the system was measured at more than 90%, confirming the promise of this technology.

Florence Lambert, Director of CEA Liten:

We are convinced that hydrogen as an energy vector will play a major part in energy transition. For us, these system-scale results confirm that high-temperature electrolysis is a credible alternative for economically viable hydrogen production, with no need for fossil fuel resources. With our experience in recent years in electrochemical converters and thermal process optimization, we have now reached an unprecedented level of technological maturity.”