Colloquia

Samenvatting

This thesis delves into the integration of a Planetary Boundaries (PB) framework within the Life Cycle Assessment (LCA) methodology, focusing on the comparative analysis of Alkaline and Proton Exchange Membrane (PEM) electrolysis for hydrogen production. The PB framework is rooted in the Earth's capacity to naturally absorb specific emissions, and exceeding these thresholds raises environmental risks. By applying the PB framework to LCA results, the study identifies key environmental indicators with the most significant impact, providing insights for targeted improvements.

Utilizing the GaBi modelling software, the research combines desk research and expert consultation to gather data for the LCA. The study considers two scenarios (worst-case and best-case) for both current (2019) and future (2050) states of the electrolysers. Challenges related to modelling the end-of-life phase are explored, whilst also giving inside into material scarcity concerns. The LCA results, presented with and without the PB framework, offer a comprehensive environmental sustainability analysis, highlighting differences between electrolyser technologies and the effect that this PB framework has on the LCA results.

The findings underscore that electricity used during the electrolysis process has the most substantial impact, identical for both Alkaline and PEM electrolysis. Notably, the extraction phase of materials reveals a high eco-toxicity indicator during nickel extraction for Alkaline electrolysers, surpassing PB in present and future worst-case scenarios. Other indicators in these extraction phases remain below PB in all scenarios. The conclusion suggests that Proton Exchange Membrane electrolysis is the more sustainable option, due to the negative impact of the high eco-toxicity found in nickel extraction for Alkaline electrolysers.