A Masterclass at the World Electrolysis Congress 2024 in Düsseldorf, Germany

By Johann Wiebe, Executive Director of Hydrogen Standard

The World Electrolysis Congress 2024 this year kicked off with a masterclass that delved into the intricacies of electrolysis. The event was structured into six insightful sessions, divided between two parallel streams, A and B.

In Stream A, Bianca Grabner and Michael Richter from Hycenta, a hydrogen technology research hub, led a session on Advanced Electrolyser Design Methods. They began with a comparative analysis of the three primary electrolyser types: PEM, Alkaline, and AEM. Alkaline electrolysers were noted for their cost-effectiveness and longevity, while PEM electrolysers were lauded for their design flexibility and efficiency at lower loads. AEM electrolysers, a newer entrant in the field, were highlighted for integrating the benefits of both PEM and Alkaline, despite being in the nascent stages of development.

Image 1: Advanced Testing Strategies

 

The duo emphasised the importance of a methodical approach in constructing an electrolyser, starting from individual components and working up to the complete module. They underscored the necessity of rigorous testing at each phase to ensure optimal functionality. The session concluded with a series of practical demonstrations, including testing protocols, flowfield comparisons, and both simulation and experimental testing.

Concurrently, in Stream B, Stephen Harrison from sbh4 Consulting shared his expertise on Managing Water Through the Electrolysis Process. He stressed that water, being the cornerstone of green hydrogen production, must undergo thorough purification, regardless of its source—be it seawater, river, or tap.

He outlined five key guidelines for PEM and Alkaline electrolysis:

• It takes 2 litres of seawater to produce 1 litre of fresh water.
• To obtain 1 litre of ultrapure water, 1.5 litres of fresh water are needed.
• A supply of 9kg of ultrapure water is essential to generate 1kg of hydrogen gas.
• The water recirculation rate within the electrolyser should be 250 to 500 times the makeup water feed rate.
• For systems cooled by cooling towers, the cooling water top-up rate is between 23 to 30 kg water/kg H.

Stephen also discussed the susceptibility of electrolyser technologies to impurities, which can significantly degrade the catalyst. For SOEC, compounds like Silica, Siloxanes, and Sulphur pose challenges. PEM electrolysers struggle with cations such as Na+, Ca2+, and Mg2+, which trigger various degradation mechanisms. In Alkaline and AEM electrolysers, CO2 levels must be carefully monitored.

The presentation highlighted the critical role of water purification systems, which, while only a fraction of the overall capital expenditure (approximately 10% for a PEM system), can prevent significant operational issues and equipment damage.

He also discussed the broader economic and environmental implications of expanding electrolyser capacity globally. While the hydrogen economy does increase water demand, it does so to a lesser extent compared to sectors like agriculture, industry, and municipal services.

Image 2: Water Use by Enduser

Post-lunch, Stream A resumed with a session on Improving Electrolyser Stack Performance by Bruno G. Pollet, President of the Green Hydrogen Division at the International Association for Hydrogen Energy (IAHE). Bruno referenced a recent IEA study that provided a snapshot of the hydrogen sector’s current state, highlighting the challenges in meeting production targets, cost reduction, and CO2 emission commitments.

The session also addressed the evolving nomenclature within the hydrogen industry, noting the shift from ‘green’ to ‘renewable’ hydrogen, and from ‘grey’ to ‘fossil’ hydrogen, with ‘blue’ and ‘yellow’ hydrogen now falling under the ‘low-carbon’ category.

Image 3: Renewable Hydrogen Production Routes

Innovation in electrolyser technology was a focal point, with discussions on catalyst development, membrane materials, electrode design, and current density optimisation. The collaborative efforts of researchers in enhancing anion exchange membrane electrolysers (AEMEs) were spotlighted, aiming to improve conductivity, chemical stability, and membrane durability. The exploration of non-precious metal catalysts and composite electrode materials was also featured, to boost efficiency and extend lifespan.

Stream B’s session, Safety First! Managing Electrolyser Safety Effectively, presented by Mareike Strub and Mark Hailwood, from the government of Baden-Württemberg emphasised the paramount importance of safety in green hydrogen production. They covered comprehensive safety management, explosion protection, risk assessment, functional safety, and safety leadership. The session concluded with the assertion that the success of green hydrogen production hinges on robust safety management systems, diligent maintenance, sustained safe operations, and strict adherence to safety standards.

Image 4: Safety Steps

The final session in Stream A, led by Lukas Schuffelen, a partner at BET, focused on the Market Integration of Electrolyser to Volatile Renewable Power. Lukas discussed the significance of regulatory requirements for low-carbon hydrogen production, the valuation of renewable power purchase agreements (PPAs), market optimisation, and the dynamics of electricity pricing. He also explored strategies for cost reduction and the role of hydrogen in the sector transition, emphasising the need for innovative solutions to advance the energy transition and achieve sustainability goals.

Image 5: Central Component of a PPA

Furthermore, he explored strategies for cost reduction through market optimisation, aiming to lower hydrogen production costs over operational decades. The role of hydrogen in sector transition is underscored, pointing towards growing demand across various sectors by 2030. Additionally, he delved into the development of electricity price spreads, noting changes in daily price differentials and the significance of battery storage systems in enhancing market flexibility.

Back in Stream B, Stephen Harrison returned to discuss Navigating Electrolyser Supply Chains. He examined the manufacturing processes, materials selection, technology trade-offs, and supply chain logistics crucial to green hydrogen technology. Highlighting companies like Plug Power, he spoke about redesigning products for mass production to cut costs and enhance operational efficiency. The session also featured a case study of Sinopec Kuqa, illustrating the importance of material selection and technology trade-offs in balancing cost, safety, and operability. Stephen concluded by underscoring the significance of supply chain management, manufacturing scale-up, capital expenditure reduction, and the development of new materials to improve electrolyser efficiency and durability.

Image 6: Balancing Factors