Environmental and cost assessments criteria for selection of promising palladium membranes fabrication strategies

Abstract

Different strategies to prepare H2-selective composite-membranes demonstrate promising performances, although the selection of the optimum alternative must consider environmental and economic concerns. These aspects, scarce in the available literature, are addressed here to analyze the convenience of using diverse CeO2-based intermediate layers in composite Pd-membranes and recommend a maximum membrane length for scaling-up. The replacement of raw dense-CeO2 by porous or Pd-doped particles in the intermediate layer clearly improves the membrane performance, saving around 50% of required Pd-thickness while increasing the H2-permeance. However, porous-CeO2 almost doubles the major environmental impacts and support modification costs, overcoming the potential saving costs in palladium. On the contrary, dense Pd-doped CeO2 mitigates the environmental impacts by 27% and simultaneously saves 24% of expenses. Further reductions in environmental impacts and costs were reached after increasing the membrane-length up to 25 cm, becoming further improvements almost negligible for longer membranes.