Life Cycle Environmental Impact Assessment of lab-scale preparation of porous alumina pellets as substrate for hydrogen separation metal layer-based membranes

The study aimed to identify the environmental hotspots of lab-scale preparation of high purity porous Al2O3 pellets with suitable feature to work properly as metal layer-based deposition substrates for hydrogen separation membranes. The work intention was providing hints that may help the designing of upscaled systems, fundamental for the development of a possible future industrial production of hydrogen separation metal layer-based membranes technology. The goal of this study was achieved assessing and analyzing environmental impacts of Al2O3 pellet production at lab scale. Primary data were collected in Padua laboratories of National Research Council of Italy. Secondary data were retrieved from Ecoinvent 3.7 database. Life cycle assessment (LCA) was performed using Environmental Footprint 3.0 method employing SimaPro 9.3 as software. Moreover, the CML LCIA method v. 4.7 was used to verify the robustness analysis of characterized results. Life cycle impact assessment highlighted as the main driver of environmental impacts was mainly associated to the pellet consolidation process and their morphological characterization stage. In particular, the impact of the first energy consuming process resulted strictly related to the peculiar energy mix used (linked to the laboratory geographical location). Conversely, morphological characterization stage was found to affect mainly the mineral resource depletion category due to the Au coating used for performing scanning electron microscope (SEM) analyses. The study identified the environmental hotspots related to lab-scale preparation of porous alumina pellets as substrate for hydrogen separation metal layer-based membranes. The optimization strategies evaluated in this work were addressed to improve the environmental profile of experimental activities considering several scenarios, in view of a possible industrial scale-up.