DESC0024963

This proposal is in response to DOE topic C58-12b, which seeks a cost-effective method to separate pure H2 from gas mixtures. We propose the development of very thin and active dense composite Pd-alloy membranes on cost- effective ceramic supports with <25 nm roughness. Globalĺs dense nano-structured Pd-alloy membranes are <200 nm thick and have a high thermochemical stability and surface activity for the prolonged transport of H2. Due to the <200 nm thickness, the membranes have much higher permeances than traditional thicker Pd-alloy membranes. Since they require >200 times less Pd, Pd costs are kept within $80/m2. However, like all Pd membranes the Pd in our nanolayers must be alloyed to improve resistance to a destructive phase transformation and formation of carbon and sulfur compounds. The Pd alloy will be ôsandwichedö between two meso-porous nano- composites of Pd-alloy particles and CeO2 particles. This improves H2 surface transfer kinetics and stability against surface tension driven reorganization. In the proposed project, Global will deposit ôsandwichedö dense composite Pd-alloy nanolayers onto our tubular alumina supports. Performance measurements will be carried out for H2 permeance, H2/N2 selectivity and stability over 100 hrs. Membrane microstructures will be analyzed post synthesis and postmortem, The most promising membrane structures will be used as starting points for further optimization and scale-up experiments with practical feeds in a Phase II effort. We envision, in subsequent scale-up and commercialization efforts, H2 separation units with a capacity of 1 metric ton/day. To realize a hydrogen-based economy first and foremost application of hydrogen combustion must be cost-competitive with respect to current technologies. With the increasing demand for purified or Blue H2 for automobiles, Brown H2 must be purified to Blue H2 without significantly adding to the cost. Use of membranes is the most straightforward way to accomplish this. To reach the ultimate goal of a Green Hydrogen economy, membranes will still play an important role in purifying H2 without a carbon footprint. Globalĺs membrane technology has the potential for the high H2 fluxes and selectivities and low price point needed to make a definitive impact in purification of H2 on a worldwide scale. Summary for members of congress: We are developing thin Pd-alloy membranes on alumina supports to enable cost-effective purification of hydrogen. This hydrogen is needed to implement an environmentally friendly and cost competitive hydrogen economy, particularly for transport applications that require pure H2 as fuel.