1. ANLEC R&D COMMUNICATION PACK (3-0510-0040)

2. While the vanadium alloy membranes are an embryonic technology, which require further demonstration are larger scales, they show promise. Alloy Membrane Reactor for Pre-Combustion CO 2 Capture Final Report. April 2015. The replacement of conventional gas processing systems in the low emissions, coal based, pre-combustion capture process with one that offers significant efficiency and cost advantages could lead to a quicker commercialisation of the technology. Despite not meeting the US DOE 2015 performance or cost targets the current assessment of the technology does confirm the potential feasibility of the alloy membrane reactor technology. So, while still in the early phase of development, future improvements in membrane performance, along with performance data from industrial slipstream trials, will refine the data and provide a more accurate picture of its potential. Pre-Combustion Capture Alloy Membrane Reactor for Pre-Combustion CO 2 Capture

3. The successful integration of various coal gas conversion processes into a single process may reduce the commercialisation barrier of this technology. Pre-Combustion Capture Alloy Membrane Reactor for Pre-Combustion CO 2 Capture Project Context: Pre-combustion carbon dioxide capture is when the energy content of coal is converted into a gas in various stages to produce hydrogen and carbon dioxide. The hydrogen is then combusted – and the carbon dioxide ‘pre combustion’ captured. The current pre-combustion capture methodology is capital intensive. One means of reducing the capital intensity is by making process of converting the coal derived gas into hydrogen and carbon dioxide more efficient. It is in this context, this project is placed. Area of Focus

4. The successful demonstration of an Alloy Membrane Reactor offers better efficiency and cost benefits compared with conventional technologies. Project Objectives: Fabricate a reliable vanadium based metal alloy hydrogen selective membrane. Demonstrate a tubular or planar membrane with an acceptable flux. Demonstrate that the developed system is able to be scaled up. Reduce the water-gas-shift and separation costs using this catalytic membrane reactor compare with conventional technologies. The US DOE has set performance and costs targets for this style of technology – which this project seeks to achieve and are seen as the technology success criteria. Pre-Combustion Capture Alloy Membrane Reactor for Pre-Combustion CO 2 Capture The hydrogen transport mechanism in an alloy membrane

5. The technology is in the early stage of development and intermediate scale industrial evaluations are required to further prove the technology. What has the CSIRO established in this work? The vanadium – aluminium alloys are a promising candidate for reducing the capital costs of pre-combustion carbon capture. The main limitation of vanadium based alloy membranes has been its susceptibility to hydrogen embrittlement – this project has developed a (patent-applied-for) alloy with improved embrittlement resistance, and appropriate mechanical properties for conventional tube drawing. A scale up factor of 500 has been achieved in the current test work – demonstrating the vanadium membrane technology can be scaled further using proven industrial manufacturing techniques. The preliminary economics suggest that better than parity with existing technologies may be possible. The technology is still several orders of magnitudes away from commercial deployment and that intermediate industrial evaluations are required to prove the technology and refine the economic analysis. Pre-Combustion Capture Alloy Membrane Reactor for Pre-Combustion CO 2 Capture

6. The embrittlement mechanism of most vanadium alloy membranes has been eliminated at above 30°C with the V 90 Al 10 alloy. Membrane Material Development The impact of this work is to identify the alloy and appropriate steady-state and start-up/shut down operating conditions which will also deliver maximum stability and durability. The addition of 10% aluminium to vanadium to make the alloy membrane V 90 Al 10 suppresses the critical temperature to less than 30°C – enabling this material to be cycled both thermally and hydrostatically while precluding the embrittlement formation mechanisms. This eliminates one of the major issues with vanadium based alloy membranes in a hydrogen environment. This significantly increases the robustness of this material relative to vanadium. Pre-Combustion Capture Alloy Membrane Reactor for Pre-Combustion CO 2 Capture V-H Phase diagram and indicative phase diagram for V 90 Al 10 (right), with shutdown pathways from steady state to rest state.

7. Several vanadium alloys have shown promise with reduced hydrogen absorption while maximising hydrogen diffusivity. Alloy Effect on Hydrogen Permeability Hydrogen permeability is one of the three prime considerations when selecting an alloy for a hydrogen- selective membrane application. The others are phase stability and mechanical formability. Several vanadium alloys have shown promise relative to pure vanadium. Calculated hydrogen diffusivities follow the trend V-Cr > V-Al > V-Ni, with the diffusivity of all the alloys showing a strong concentration dependence. This data combined with mechanical properties (the ability to form the membrane) and phase stability during cycling (embrittlement) will aid the selection of the optimum membrane. Pre-Combustion Capture Alloy Membrane Reactor for Pre-Combustion CO 2 Capture 1 H Hydrogen 1.01 1 H Hydrogen 1.01 23 V Vanadium 50.94 23 V Vanadium 50.94 24 Cr Chromium 52.00 24 Cr Chromium 52.00 28 Ni Nickel 58.70 28 Ni Nickel 58.70 13 Al Aluminium 26.98 13 Al Aluminium 26.98

8. The ‘native’ mechanical properties of the vanadium aluminium alloys can be enhanced and facilitate the use of standard tubular manufacturing techniques. Mechanical Properties To facilitate manufacture through a deformation process such as extrusion or rolling, the alloy must exhibit sufficient deformability. Alloying vanadium is essential to reduce the embrittlement from hydrogen. Understanding various alloy’s mechanical properties is essential. The vanadium nickel alloys investigated have very low ductility – severely limiting their ability to be formed into membrane sheets or tubes. The vanadium aluminium alloys showed far greater ductility. Pre-Combustion Capture Alloy Membrane Reactor for Pre-Combustion CO 2 Capture Microstructure Ductility of the vanadium alloy can be enhanced by minimising the grain size of the alloy. The more ductile vanadium aluminium alloy with the addition of grain refiners have very fine grains without degrading hydrogen permeability. Hot isostatic pressing reduces grain size and increases size uniformity as well as decreasing voids. These effects all improve ductility of the alloy. Grain size formed after casting in V 95 Al 5 alloy (left) and V 95 Al 5 with grain refiners (right)

9. The performance of the palladium / vanadium / nickel membrane performed adequately, but offers no economic advantage over conventional material. Layered Membranes Palladium-based membranes are the clear (expensive) industry benchmark for alloy membrane technologies. This work sought to create a membrane from highly permeable but less expensive metals (vanadium, nickel and aluminium). In addition, the layered configuration provides the opportunity to deposit different catalysts on the feed and permeate surfaces of the membrane. For these experiments an asymmetric palladium / vanadium / nickel combination was tested. The work concluded that while nickel showed promise as a palladium replacement, with membrane performance highly dependent on nickel thickness, no cost advantage was achieved. A significant increase in palladium or a significant reduction in manufacturing costs would be required to achieve an economic advantage of the nickel combination. Pre-Combustion Capture Alloy Membrane Reactor for Pre-Combustion CO 2 Capture Do time and financial constraints, the project could not produce a vanadium alloyed membrane. An alternative approach, using layered configuration was investigated to further the science and modelling for this project. Do time and financial constraints, the project could not produce a vanadium alloyed membrane. An alternative approach, using layered configuration was investigated to further the science and modelling for this project.

10. Despite not meeting the technical and economic US DOE goals, the vanadium alloy membrane reactor shows potential. Membrane Economics Given the pre-commercial nature of the alloy membranes, cost estimations is a difficult assignment. Compared with the industry standard palladium based membranes, the vanadium based alloys offer a much lower cost alternative, which are also immune from palladium price volatility. Despite not meeting the US DOE 2015 flux or cost targets the economic assessment of the technology does confirm the potential feasibility of the technology for pre-combustion CO 2 capture at its current state of development. Future improvements in membrane performance, along with performance data from industrial slipstream trials, will refine the economic data and provide a more accurate picture of its potential. Pre-Combustion Capture Alloy Membrane Reactor for Pre-Combustion CO 2 Capture