The use of ammonia (NH3) as a hydrogen vector can potentially enable renewable energy export from Australia to markets in Asia and Europe. With a higher hydrogen density than liquid H2, plus existing production and transport infrastructure, and well-developed safety practices and standards, the financial and regulatory barriers to this industry are lower than for liquid H2 transport. The only significant technical barrier which remains, however, is the efficient utilisation of ammonia fuel at the near the point of use, either directly or through the production of H2.
For H2 production from NH3, the purity of the product H2 is the prime consideration. As NH3 can degrade the polymer electrolyte in PEM fuel cells, the relevant purity standard for mobile PEM fuel cell applications (ISO14687-2) sets a maximum NH3 concentration of just 0.1 ppmv. Furthermore, the allowable N2 limit is 100 ppmv N2 due to the significant energy penalty that N2 introduces during compression, as well as the risk of NH3 formation through reaction with H2.
Of currently available H2 separation technologies, metal membranes show particular promise as they combine infinite H2 selectivity (i.e., a 100% pure H2 product, assuming a defect-free membrane), high temperature operation (comparable to that required for NH3 decomposition) and tolerance to NH3. CSIRO, in a collaboration with BOC/Linde, is demonstrating a pilot-scale ammonia-to-hydrogen system which integrates vanadium-based membranes with a cracking catalyst to produce high-purity H2 directly from NH3, at a rate of at least 5 kg H2 per day. Please read ABC report - demonstration day at CSIRO QCAT. http://www.abc.net.au/news/2018-08-08/hydrogen-fuel-breakthrough-csiro-game-changer-export-potential/10082514
When scaled and deployed at FCEV refuelling stations, this technology will help enable a renewable ammonia export industry from Australia to the major economies of Asia and beyond.
About the Speaker – Dr Michael Dolan
Michael Dolan is a Principal Research Scientist and Team Leader with CSIRO Energy in Brisbane. Michael leads a team which investigates H2 production from a range of fossil and renewable resources, a key aspect of which is the development of hydrogen-selective metal membranes. This technology is presently being demonstrated at the pilot-scale for the generation of high-purity H2 from ammonia, work which is central to the establishment of a renewable hydrogen export industry in Australia. Michael holds a B.App.Sc (Hons) and PhD from La Trobe University, and an MBA from Torrens University. He has published more than 50 research papers on energy-related materials and processes.
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