Pressurised SOFC system with anode exhaust gas recirculation

The pressurised SOFC system is a large-scale research unit run by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) Institute of Engineering Thermodynamics in Stuttgart. It offers the unique possibility of studying large solid oxide fuel cell modules with anode exhaust gas recirculation while varying the pressure, temperature and fuel. The fuel cells used here are solid oxide fuel cells (SOFCs).

Fuel cells under pressure and heat

The SOFC, a high-temperature fuel cell, is superbly suited to stationary power and heat generation due to its high efficiency and low pollutant emissions. It converts high-efficiency chemical energy into electrical energy. It is possible to use renewable hydrogen as well as carbon-based fuels such as natural gas and biogas due to the integrated catalytic steam reformer, which is operated by hot recirculated exhaust gases.

The system is designed for an electrical output of 30 kW. A high-temperature blower is used to adjust different recirculation rates for the anode exhaust gas at the anode inlet. The system can be loaded up to 5 bar (absolute). As it emulates a coupled microgas turbine, the structure of the system allows hybrid power plant operations to be researched in a realistic laboratory.

The Institute of Engineering Thermodynamics is investigating the stationary and dynamic behaviour of large SOFC systems. Different regulatory strategies and operating concepts are being analysed there, as it is possible to implement wide operating ranges with the highest possible efficiency and fast power changes.
The research activities are geared towards demonstrating the technical feasibility of highly efficient and fuel-variable power plants with low emissions and investigating large stationary high-temperature fuel cell modules within a system context.


Volker Speelmann

Head of Research Infrastructures
German Aerospace Center (DLR)
Executive Board department for Innovation, Transfer and Research Infrastructure
Linder Höhe, 51147 Cologne

Prof. Dr. rer. nat. K. Andreas Friedrich

Head of Department
German Aerospace Center (DLR)
Institute of Technical Thermodynamics
Electrochemical Energy Storage