Production & Supply Chain

Global attention is being given to hydrogen as it is seen as a versatile energy carrier and a flexible energy vector in transitioning to a low-carbon economy. Hydrogen production/storage/conveyance is metal intensive and it is crucial to understand if there is material availability to fulfil the committed plans. Using the material intensity of electrolysers pipelines and desalinators along with the projected Portuguese and European Union roadmaps we are able to identify possible bottlenecks in the supply chains. The availability of the vast majority of raw materials does not represent a threat to hydrogen technologies implementation with electrolysers requiring almost up to 3 Mt of raw materials and pipelines up to 2.5 Mt. The evident exception is iridium although representing less than 0.001 % of the material requirements it may hinder the widespread implementation of proton exchange membrane electrolysers. Desalinators have the least material footprint of the studied infrastructure.

Electrolysis of water to generate hydrogen fuel is an attractiverenewable energy storage technology. However grid-scale fresh-water electrolysis would put a heavy strain on vital water re-sources. Developing cheap electrocatalysts and electrodes that cansustain seawater splitting without chloride corrosion could ad-dress the water scarcity issue. Here we present a multilayer anodeconsisting of a nickel–iron hydroxide (NiFe) electrocatalyst layeruniformly coated on a nickel sulfide (NiSx) layer formed on porousNi foam (NiFe/NiSx-Ni) affording superior catalytic activity andcorrosion resistance in solar-driven alkaline seawater electrolysisoperating at industrially required current densities (0.4 to 1 A/cm2)over 1000 h. A continuous highly oxygen evolution reaction-active NiFe electrocatalyst layer drawing anodic currents towardwater oxidation and an in situ-generated polyatomic sulfate andcarbonate-rich passivating layers formed in the anode are respon-sible for chloride repelling and superior corrosion resistance of thesalty-water-splitting anode.

In today’s world the need for sustainable energy solutions is paramount to address the ongoing crisis of increasing greenhouse gas emissions and global warming. Industries heavily reliant on fossil fuels must explore alternative energy sources. Hydrogen with its high heating value and zero direct emissions has emerged as a promising fuel for the future. Electrolytic hydrogen production has gained significance as it enables demand-side response grid stabilization using excess energy and the mitigation of curtailment from intermittent renewable energy sources (RES) such as solar and wind. Advanced combined heat and power (CHP) systems comprise of Solid oxide fuel cell (SOFC) module and a coupled reforming reactor to capture energy contained in the SOFC exhaust gases from SOFC. In present work 3D CFD model of an experimental coupled reactor used for onsite hydrogen production is developed and implemented into ANSYS Fluent® software. The study is aimed at opti mizing the reactor performance by identifying appropriate kinetic models for reforming and combustion re actions. SOFC anode off-gas (AOG) comprising mainly of unconverted hydrogen is combined with methane combustion to enhance thermal efficiency of the reactor and hence the CHP system. Kinetic models for catalytic reforming and combustion are implemented into ANSYS Fluent® through custom-built user defined functions (UDFs) written in C programming language. Simulation results are validated with experimental data and found in good agreement. AOG assisted combustion of methane shows a substantial improvement in thermal efficiency of the system. Improvement in thermal efficiency and reduction in carbon-based fuel demand AOG utilization contributes to sustainable hydrogen production and curtailment of greenhouse gas emissions.