PEC-Solarreactor – Solar reactor for photo-electrochemical recovery of hydrogen from wastewater

Hydrogen is an important energy carrier for achieving the set climate targets. As it is currently mainly produced from fossil fuels, great efforts are being made to produce hydrogen using renewable resources. However, the potential of renewable electricity (e.g. PV /surplus electricity) is limited and far from sufficient to achieve decarbonization in a sustainable way. Innovative ways for hydrogen production are therefore urgently needed.

The developed solar reactor for the first time combines expertise in efficient reactor systems with solar collector development and photo-electrochemical materials research. For this purpose, the photo-electrochemical process is integrated into a reactor with optimized rheology. The reactor tubes are surrounded by concentrating collector mirrors to focus the sunlight. Optimization of the reactor’s rheology ensures ideal mixing and radiation penetration, ultimately increasing hydrogen yield and improving system efficiency.

The solar reactor is being tested on polluted wastewater. The wastewater offers the advantage that dissolved pollutants serve as sacrificial agents and thus “source” of the hydrogen and are degraded in the process.

As a result of the project, a proof-of-concept of a real tested solar reactor (real wastewater, real irradiation conditions) is available, whose potential analysis as well as holistic overall concept considering combined resource and energy efficiency as well as utilization strategies for the hydrogen pave the way for the next development steps towards a marketable product.