Prospective Life Cycle Assessment of Hydrogen production with next-generation low-iridium PEM Electrolyzers

The latest advancements in proton exchange membrane water electrolysers (PEMWE) for hydrogen production, highlight the need for increased manufacturing capacity and the challenge of relying on critical raw materials like iridium and platinum. However, the effectiveness of electrolysers hinges on the broader decarbonisation of the energy system, underscoring the importance of analysing future electricity and its impact on hydrogen production. This paper presents a comprehensive prospective life cycle assessment (pLCA) on the fabrication and use of a next-generation PEMWE, which incorporates novel approaches to reduce iridium content without compromising its efficiency and its ecological footprint. The functional unit is 1 kilogram of hydrogen at 30 bar, with a cradle-to-grave approach. The chosen impact assessment method is ReCiPe 2016 (H). The "premise" tool is utilised to create the prospective background database. For the fabrication of the low-iridium PEMWE an evolving life cycle inventory (LCI) and operational parameters are employed. For the use phase, the electricity scenarios derived from the optimised energy scenario for Germany are applied. For the end of life, an economical allocation was considered. The PEMWE stack and plant play no significant role, most emissions are attributable to electricity generation. The significant reduction in impacts from electricity is not only due to a reduction in the impacts of electricity but also to an increase in the efficiency of the electrolysis stack. The production of electricity-based hydrogen is not yet viable from a climate perspective compared to conventional grey hydrogen. However, this changes with an increase in the share of renewable energy in electricity generation. The pLCA allows identifying direct trade-offs from the electrolyser fabrication, performance, and use, including the consumed electricity and the whole supply chain and background processes, which gives a more comprehensive understanding of the system. This study offers a comprehensive examination of the fabrication process and use of a next-generation PEMWE. Our findings underscore the critical importance of updating background data, which serves as a primary driver influencing the environmental impacts of hydrogen production. While infrastructure development for the electrolyser plays a subordinate role in comparison, the efficiency of the system and its consequent electricity consumption emerge as pivotal factors.      «

The latest advancements in proton exchange membrane water electrolysers (PEMWE) for hydrogen production, highlight the need for increased manufacturing capacity and the challenge of relying on critical raw materials like iridium and platinum. However, the effectiveness of electrolysers hinges on the broader decarbonisation of the energy system, underscoring the importance of analysing future electricity and its impact on hydrogen production. This paper presents a comprehensive prospective life...     »