Critical materials in PEMFC systems and a LCA analysis for the potential reduction of environmental impacts with EoL strategies

Abstract

Commonly used materials constituting the core components of polymer electrolyte membrane fuel cells (PEMFCs), including the balance‐of‐plant, were classified according to the EU criticality methodology with an additional assessment of hazardousness and price. A life‐cycle assessment (LCA) of the materials potentially present in PEMFC systems was performed for 1 g of each material. To demonstrate the importance of appropriate actions at the end of life (EoL) for critical materials, a LCA study of the whole life cycle for a 1‐kW PEMFC system and 20,000 operating hours was performed. In addition to the manufacturing phase, four different scenarios of hydrogen production were analyzed. In the EoL phase, recycling was used as a primary strategy, with energy extraction and landfill as the second and third. The environmental impacts for 1 g of material show that platinum group metals and precious metals have by far the largest environmental impact; therefore, it is necessary to pay special attention to these materials in the EoL phase. The LCA results for the 1‐kW PEMFC system show that in the manufacturing phase the major environmental impacts come from the fuel cell stack, where the majority of the critical materials are used. Analysis shows that only 0.75 g of platinum in the manufacturing phase contributes, on average, 60% of the total environmental impacts of the manufacturing phase. In the operating phase, environmentally sounder scenarios are the hydrogen production with water electrolysis using hydroelectricity and natural gas reforming. These two scenarios have lower absolute values for the environmental impact indicators, on average, compared with the manufacturing phase of the 1‐kW PEMFC system. With proper recycling strategies in the EoL phase for each material, and by paying a lot of attention to the critical materials, the environmental impacts could be reduced, on average, by 37.3% for the manufacturing phase and 23.7% for the entire life cycle of the 1‐kW PEMFC system.

Economic analysis and environmental assessment of aluminum debris power generator for deployment to communal-scale disaster areas

“…The POCP, EP, AP, and GWP of the aluminum fuel production are attributable to gallium and indium consumption. Although the amount of gallium and indium is small, these rare metals are categorized as critical materials by the European Parliament (2017) according to two assessment criteria: economic importance and supply risk ( Stropnik et al., 2019 ). Given that these metals are expensive, improving their recovery rate would increase their economic and environmental profiles.…”

“…Therefore, the end-of-life phase of these materials should be carefully considered. Stropnik et al. (2019) demonstrated that with proper recycling of these critical materials, the environmental impact could be reduced by 24% on average throughout the life cycle for a 1 kW PEMFC.…”

“…Electricity generation module (Data sources: Noguera, 2014 ; Stropnik et al., 2019 ; Dhanushkodi et al., 2008 ; Dai et al., 2019 ; GaBi professional database)…”

Exploring the Structure–Performance Relationship of Sulfonated Polysulfone Proton Exchange Membrane by a Combined Computational and Experimental Approach

“…The model was finally filled with TIP3P water molecules and Na + counterions have been added to neutralize the charge, to a total number of 122,873 atoms. For this model, the periodic boundary conditions have been fixed and the final box was of 138 × 110 × 100 Å 3 . A detailed description on the setup of the model is provided in the Supporting Information.…”

“…Regarding the PEMs, the state of the art is still based on Nafion ® , the perflurosulfonic acid (PFSA) membrane produced by DuPont TM via the copolymerization of an unsaturated perfluoroalkyl sulfonyl fluoride (PSF) with tetrafluoroethylene (TFE). Its price alone is expected to be approximately 30% of the vehicle's selling price [2], while if we analyze its environmental impact in terms of the so-called global warming potential (GWP), Nafion ® material has the largest impact respect to all the other components of a PEMFC stack [3]. This effect can be easily explained if the manufacturing process of the main substances needed for the polymer synthesis is taken into account.…”