HycycleS - A Project on Nuclear and Solar Hydrogen Production by Sulfur Based Thermochemical Cycles

Abstract

The European FP7 project HycycleS is a European R&D Project on the development of thermo-chemical hydrogen production processes. It concentrates on providing detailed solutions for the design of specific key components for sulfur based thermochemical cycles. The key components necessary for the high temperature part of those processes, the thermal decomposition of H2SO4, and the ones targeted are a compact heat exchanger for SO3 decomposition suitable for operation by solar and nuclear heat, a receiver-reactor for solar H2SO4 evaporation and SO3 decomposition, and an oxygen separator for SO2 and O2 as product separator and as promoter of the SO3 decomposition. Silicon Carbide (SiC) has been identified as the preferred material and is investigated in detail with respect to its use at high temperature and in a highly corrosive atmosphere for the use as a solar absorber or as plates in a heat exchanger. Another focus is catalyst materials for the high temperature reduction of SO3. Requirement specifications were set up as basis for design and sizing of the intended prototypes and mock-ups. Test rigs for different purposes – corrosion tests, catalyst development, catalyst stability tests, and selectivity of separation membranes - have been designed, built and completed. Prototypes of the mentioned components have been designed and will start operation soon.