Europe’s transition to a decarbonised energy system, as outlined in the EU Green Deal, will transform how the EU generates, distributes, stores, and consumes energy. Hydrogen will become an important energy vector, as well as a chemical reactant for the decarbonisation of energy-intensive industries like steel. However, as hydrogen is a light, flammable gas, it is difficult to store and transport, and there is always an inherent safety risk. In contrast, ammonia (NH3) is a clean, carbon-free hydrogen carrier with good volumetric and gravimetric energy densities and zero flammability. Green ammonia (produced using renewable energy) could be used as a hydrogen source and then make it available on demand for fuel cells in many applications, so solving the problem of hydrogen storage and transportation. While the catalytic materials for ammonia decomposition are well known (e.g. Ru, Ni), a catalytic reactor/converter with the necessary capabilities must be developed before we can exploit ammonia decomposition as part of a green-hydrogen energy system. For thermodynamic reasons, ammonia can only be decomposed at temperatures of 450 °C. Furthermore, a conventional, passive catalytic reactor requires either the whole reactor – consisting of an inert support material (ceramic tubes or ceramic powder bed) and an active catalyst (e.g. Ru, Ni) – to be heated by convection and/or radiation or for the reaction mixture to be preheated in a heat exchanger before entering the reactor. In both cases a lot of energy is wasted by heating the reactants and the reactor walls. In addition, the time required to reach the reaction temperature hampers the on-demand production of hydrogen.
In this project bottom-up design was applied to fabricate a modular multiscale ceramic catalytic reactor based on embedded magnetic nanoparticles that can provide carbon-free hydrogen on demand by rapidly decomposing ammonia. This approach will reduce energy consumption and improve the reaction kinetics, as well as making possible the decentralised availability of green hydrogen at a reasonable cost.
While the final goal of the project was to demonstrate the viability and advantages of the proposed approach, its main research focus has been on the AM of ceramic catalytic reactor components with magnetic functionality induced by the in-situ formation of magnetic nanoparticles.
The objective was to design and additively manufacture a Si(O)C catalytic support with a porous structure and magnetic functionality induced by (in-situ formed) magnetic nanoparticles exhibiting magnetic heating capability.
The main objective of the proposal was divided into three manageable sub-objectives:
Objective 1: Synthesis of a metal-functionalised, pre-ceramic polymer, yielding a ceramic soft-magnetic nanoparticle (such as Fe3O4/Fe) composite after pyrolysis (WP1)
Objective 2: Design, AM and catalytically functionalise a complex-shaped ceramic catalytic reactor (WP2)
Objective 3: Validate a magnetically heated reactor for carbon-free hydrogen delivery based on the on-demand decomposition of ammonia. (WP3)
