Coupling Heat and Electricity Sources to Intermediate Temperature Steam Electrolysis

Abstract

The use of CO2-free energy sources for running SOEC (solid-oxide electrolysis cell) technologies has a great potential to reduce the carbon dioxide emissions compared to fossil fuel based technologies for hydrogen production. The operation of the electrolysis cell at higher temperature offers the benefit of increasing the efficiency of the process. The range of the operating temperature of the SOEC is typically between 800 °C and 1,000 °C. Main sources of degradation that affect the SOEC stack lifetime is related to the high operating temperature. To increase the electrolyser durability, one possible solution is to decrease the operating temperature down to 650 °C, which represents the typical operating range of the ITSE (intermediate temperature steam electrolysis). This paper is related to the work of the JU-FCH project ADEL, which investigates different carbon-free energy sources with respect to potential coupling schemes to ITSE. A predominant focus of the analysis is put on solar concentrating energy systems (solar tower) and nuclear energy as energy sources to provide the required electricity and heat for the ITSE. This study will present an overview of the main considerations, the boundary conditions and the results concerning the development of coupling schemes of the energy conversion technologies to the electrolyser.