Life Cycle Assessment of Hydrogen Generation by Polymer Electrolyte Membrane Electrolyzers

past

Semester project
Autumn 2023

Context

The European Union uses 9.7 million tonnes of hydrogen annually. 95% of this hydrogen is generated from natural gas and coal which cogenerate CO2. Only 5% comes from electrolysis [1], mostly of non-renewable origin. Hydrogen is now mostly used in the chemical industry (to produce ammonia, methanol and treat oil), in metal and semiconductor treatment, and other applications. On the other hand it could serve as large scale energy storage for renewable electricity sources. Since most renewable sources are intermittent, there is sometimes excess electricity available. Storage as hydrogen can use this surplus of electricity thus avoid wasting it. There are different types of electrolyzers : Alkaline Electrolyzers (AEL and AEMEL), Polymer Electrolyte Membrane Electrolyzers (PEM), and Solid Oxide Electrolyzers (SOE). The efficiencies of AEL, PEM and SOE are about 60%, 70% and 90% respectively [2]. Concerning size, efficiency and cost, PEM is considered an intermediate option for energy storage, particularly for small-scale power plant applications. Although PEM is promising in some fields, it faces some economic challenges from competitive technologies, and its materials supply chain relies heavily on critical raw materials (CRM), which brings additional strains and leads to difficulty in long term / large scale use of PEM technology. Therefore, it is critical to build a LCA model on PEM manufacturing first, to understand which manufacture steps can be improved, to reduce emissions and other impact factors. After detecting the key processes, sensitivity analyses can be carried out on material recycling rate, energy replacement etc. A LCA model will be conducted through OpenLCA software. The work will be done in collaboration with GEM and IPESE laboratories.

The project / tasks

  • Understanding H2 production technologies, particular for PEM system.
  • Conducting the LCA for the PEM manufacturing process.
  • Detecting the key processes via the results, and carrying out the sensitivity analyses for different scenarios.

Skills

  • Understanding of energy concepts and life cycle assessment
  • Results interpretation and report writing
  • Course modules: Life cycle assessment in energy systems, Energy Conversion and/or Renewable Energy

Administrative

This project is part of collaborative research work between IPESE and GEM in EPFL-Sion. The project will be supervised by Xinyi Wei (IPESE, GEM). If interested, please send your CV, with short motivation letter, to xinyi.wei@epfl.ch.

Location: This research work is conducted at EPFL, Sion. Travel expense (one day per week) will be reimbursed.

References

  1. Georgia Kakoulaki et al. “Green hydrogen in Europe–A regional assessment: Substituting exist ing production with electrolysis powered by renewables”. In: Energy Conversion and Manage ment 228 (2021), p. 113649.
  2. Jun Chi and Hongmei Yu. “Water electrolysis based on renewable energy for hydrogen produc tion”. In: Chinese Journal of Catalysis 39.3 (2018), pp. 390–394.