Periodic Reporting for period 2 - HySelect (Efficient water splitting via a flexible solar-powered Hybrid thermochemical-Sulphur dioxide depolarized Electrolysis Cycle)
Reporting period: 2024-07-01 to 2025-12-31
HySelect will demonstrate the production of hydrogen (H2) by splitting water via concentrated solar technologies (CST) with an attractive efficiency and cost, through the hybrid Sulphur cycle (HyS). The HyS consists of two central steps: the high temperature -yet below-900C - decomposition of Sulphuric acid forming Sulphur dioxide (SO2) and the subsequent low temperature (50-80C) SO2 depolarized electrolysis (SDE) of water to produce H2. HySelect will introduce, develop and operate under real conditions a complete H2 production chain focusing on two innovative, full scale plant prototype core devices for both steps of the HyS cycle: an allothermally heated, spatially decoupled from a centrifugal particle solar receiver, Sulphuric acid decomposition-Sulphur trioxide splitting (SAD-STS) reactor and a Sulphur dioxide depolarized electrolyzer (SDE) without expensive Platinum Group Metals (PGMs). Furthermore, a heat recovery system will be integrated to exploit the temperature difference within the cycle and boost the overall process efficiency. In the course of the work, non-critical materials and catalysts will be developed, qualified and integrated into the plant scale prototype units for both the acid splitting reactor and the SDE unit. Experimental work will be accompanied by component modelling and overall process simulation and culminate with a demonstration of the complete process integrating its key units of a centrifugal particle receiver, a hot particles storage system, a SAD-STS and a SDE into a pilot plant. Testing for a period of at least 6 months in a large-scale solar tower, driven with smart operation and control strategies, will establish the HySelect targeted efficiency and costs. Finally, an overall process evaluation will be carried out in order to assess the technical and economic prospects of the HySelect technology, directly linked to the know-how and developments of the Sulphuric acid and water electrolyzers industries.
The ambition of HySelect is to close the technical gaps and provide the missing links in the overall, complete HyS cycle technology concept, for a realistic overall evaluation of the technology and its scale-up. The innovations to be implemented will lead to highly efficient, long-term and cost-competitive CST-driven thermochemical hydrogen production.
The ambition of HySelect is to close the technical gaps and provide the missing links in the overall, complete HyS cycle technology concept, for a realistic overall evaluation of the technology and its scale-up. The innovations to be implemented will lead to highly efficient, long-term and cost-competitive CST-driven thermochemical hydrogen production.
A detailed plan of the HySelect demonstration plant is in place, with process simulation results and the all relevant technology blocks.
Key results until the end include:
Oxide catalytic materials composition recipes that will ensure significant SO3 splitting conversion at temperatures reachable with current solar receivers with a final selection of formulations being available
Know-how in other-than-SO3 -splitting catalytic reactions with related industries
Cascaded Sulphuric acid decomposition/SO3 splitting reactor following an allothermally-heated shell-and-tube heat exchanger design, a pre-final modular reactor design is in place.
Sulphur dioxide Depolarized Electrolyzer in the pilot-scale, detailed technical discussions with possible manufacturers are ongoing.
SDE bipolar plates with minimal amount/no PGM and anticorrosion properties, various coating techniques are investigated
New membrane materials for long term operation without SO2 crossover
Centrifugal particle receiver and high-temperature particles storage system which has been installed in the Solar tower Juelich, and commissioning is ongoing
Eventual Hydrogen production cost < 5 €/kg for a scaled plant in multi-MW size.
Impacts
New breakthrough approach for transferring heat from a solar receiver to endothermic catalytic reactions.
New catalytic ways to perform SO3 splitting via higher- and lower-temperature catalysts in cascade configurations of appropriately engineered and shaped porous structured catalytic oxide bodies.
New Sulphur Dioxide Depolarized electrolyzers with minimal or no quantities of PGMs
New niche market for electrolyser manufacturers.
New synergies for Sulphuric acid industry.
Diversification of RE-hydrogen production routes
Reduction in use of critical-PGM materials
Addition of extra renewable hydrogen in the future energy mix.
Oxide catalytic materials composition recipes that will ensure significant SO3 splitting conversion at temperatures reachable with current solar receivers with a final selection of formulations being available
Know-how in other-than-SO3 -splitting catalytic reactions with related industries
Cascaded Sulphuric acid decomposition/SO3 splitting reactor following an allothermally-heated shell-and-tube heat exchanger design, a pre-final modular reactor design is in place.
Sulphur dioxide Depolarized Electrolyzer in the pilot-scale, detailed technical discussions with possible manufacturers are ongoing.
SDE bipolar plates with minimal amount/no PGM and anticorrosion properties, various coating techniques are investigated
New membrane materials for long term operation without SO2 crossover
Centrifugal particle receiver and high-temperature particles storage system which has been installed in the Solar tower Juelich, and commissioning is ongoing
Eventual Hydrogen production cost < 5 €/kg for a scaled plant in multi-MW size.
Impacts
New breakthrough approach for transferring heat from a solar receiver to endothermic catalytic reactions.
New catalytic ways to perform SO3 splitting via higher- and lower-temperature catalysts in cascade configurations of appropriately engineered and shaped porous structured catalytic oxide bodies.
New Sulphur Dioxide Depolarized electrolyzers with minimal or no quantities of PGMs
New niche market for electrolyser manufacturers.
New synergies for Sulphuric acid industry.
Diversification of RE-hydrogen production routes
Reduction in use of critical-PGM materials
Addition of extra renewable hydrogen in the future energy mix.