1. S PA C ER ESEA RC HI N ST IT U T EAuburn UniversityAmmonia Transformation and Utilization Henry Brandhorst1, Martin Baltazar-Lopez1Bruce Tatarchuk2, Don Cahela2, ,and Troy Barron31SpaceResearch Institute2Center for Microfibrous Materials Manufacturing Auburn University3IntraMicron, Inc. 6th International Energy Conversion EngineeringConference (IECEC) 28 - 30 Jul 2008 Center for MicrofibrousSpace Research Institute Materials Manufacturing

2. S PA C ER ESEA RC HI N ST IT U T EWhy Ammonia for Energy? Auburn UniversityEliminates greenhouseDont need fossil fuelsgases (CO2, CH4, etc.)or carbon sources Safely transportableCan be synthesizedfrom water and air Ammonia has manydesirable featuresCan be burned directly Storable with high Stirling, dieselhydrogen content or IC engines (17.6%) Can be reformedSource of fuel for into H2 Stirling or IC engine or fuel cellsBut NH3 poisons PEM FCsCenter for MicrofibrousSpace Research InstituteMaterials Manufacturing 3. S PA C ER ESEA RC HI N ST IT U T E Background Auburn University Study of benefits of ammonia for terrestrial applications Develop processes forUtilize microfibrous materials catalytic reformation of NH3 to encapsulate reforming catalyst Studies on the stability andfeasibility of burning Demonstrate an NH3 NH3 and burning NH3 catalytic burnerwith synthetic reformate Operate a FPSE on hydrogen reformed from ammonia (run on H2, not on reformed NH3 yet)Center for MicrofibrousSpace Research InstituteMaterials Manufacturing 4. S PA C ER ESEA RC HI N ST IT U T EMicrofibrous Materials IntroductionBenefits and Attributes Auburn UniversityActivated Carbon Fiber and 2m Stainless Steel55-85 m sorbent entrapped in 2,4,8 m Ni fibersDefinition: Microfibrous Materials provide for the mechanical andelectrical entrapment of a particle or fibrous solid within sinter-lockednetworks of a secondary fibrous matrixAttributes: The volume loading of each phase is relatively independentof the other phase, and adjustable over a wide range compared to currentSOA materials and practicesCenter for MicrofibrousSpace Research InstituteMaterials Manufacturing 5. S PA C ER ESEA RC HWhats Unique About MicrofibrousI N ST IT U T E Materials? Auburn University Based on a simple, paper-making process Reel-to-reel fabrication demonstrated Multiple materials/material combinations Metals, polymers, ceramics e.g. Ni, stainless steels, Ti, Hastelloy, Nicrome,FeCrAl, Cu Fiber size, length options Size: 1-50 m; tow or chopped (1mm 25 mm) Can include catalysts, sorbents, etc. Able to independently control properties Tailored 3-D structures possible Center for MicrofibrousSpace Research Institute Materials Manufacturing 6. S PA C ER ESEA RC HI N ST IT U T E Why Free-Piston Stirling Engines? Auburn University externalsource of heat Can operateover a wide input temperaturerangesCenter for MicrofibrousSpace Research InstituteMaterials Manufacturing 7. S PA C ER ESEA RC HI N ST IT U T E Why Free-Piston Stirling Engines?Auburn UniversityThey are being used on earth and in space applications Low maintenance and quiet 80W convertor lifetimes over25,000 hrs demonstrated Low or no vibration when usedin dual-opposed operation High efficiency ~37%, depending on Th/Tc >90% alternator efficiency Center for MicrofibrousSpace Research Institute Materials Manufacturing 8. S PA C ER ESEA RC HI N ST IT U T E Why Free-Piston Stirling Engines? Auburn UniversityHigh specific mass (~100W/kg) Only two moving parts that make no contactMany sizes demonstrated 25 kW (1992) 35 W, 80 W, 1.2 kW New NASA 5 kWCenter for MicrofibrousSpace Research InstituteMaterials Manufacturing 9. S PA C ER ESEA RC HWhy Ammonia-Fueled Free-PistonI N ST IT U T EStirling Engines ? Auburn UniversityAmmonia, containing 17.6% hydrogen by mass, could be used withhigh efficiency and reduced pollution It is easily stored and transported safely Flammability limits of NH3 (Vol % in air) only between 15.5% and 27%Optimized NH3 reforming catalysts and the means for entrapping themin a matrix exist Relatively easy to reform NH3 to H2 Is full reformation the best choice? Of course H2/O2 combustion produces a clean flame and only water We have demonstrated catalytic combustors for NH3Including some percentage of H2 in an NH3 stream stabilizes the combustorWell use partial NH3 decomposition to show feasibility of producingtemperatures that could be used by a free-piston Stirling engineCenter for MicrofibrousSpace Research InstituteMaterials Manufacturing 10. S PA C ER ESEA RC HI N ST IT U T E Schematic Diagram of Test Set UpAuburn UniversityPreliminary burner tests were done by implementing asynthesized hydrogen reforming from NH3MFC-1H2MFC-2TemperatureN2Monitor Burner MFC-3 O2Rotameter NH3 Center for MicrofibrousSpace Research Institute Materials Manufacturing 11. Burner Tests 1: NH3 and Air Only Auburn UniversityCold apparatus Difficult to ignite NH3 combustion short-livedHot apparatus NH3 combustion ignites Extinguished when air flowis stopped Temperature: 740 CCenter for MicrofibrousSpace Research InstituteMaterials Manufacturing 12. S PA C ER ESEA RC HI N ST IT U T ENH3 Decomposition Catalyst Bed Auburn UniversityPreparation of catalyst bed Wet laid material Cellulose, 4 & 8 m Ni Alumina fibers and 150-250 micronsupport alumina powder (1:1:3.8) particle(150- Two layers placed on a250m) 120 mesh SS screen and sintered in H2 at 1000C4& 8% chloroplatinic acid used8m Nifor a loading of 10.8 wt % fiberPt on the alumina Dried at 110C and thencalcined in air at 400CCenter for MicrofibrousSpace Research InstituteMaterials Manufacturing 13. S PA C ER ESEA RC HI N ST IT U T EAmmonia Conversion Auburn UniversityCenter for MicrofibrousSpace Research InstituteMaterials Manufacturing 14. S PA C ER ESEA RC HI N ST IT U T EAmmonia-Air Catalytic BurnerAuburn UniversityA disc of microfibrous porous media was used to decomposeNH3 into H2 and N2MFC-1 AirTemperatureMonitor Burner RotameterNH3 Center for MicrofibrousSpace Research Institute Materials Manufacturing 15. S PA C ER ESEA RC H Burner Tests :Catalyst Compared toI N ST IT U T ESynthetic ReformateAuburn UniversitySynthesized reformate ofNH3 , air and H2 Ni media Stable flame Temperature: 990CNH3 plus air thru catalyzedbed with 4.5 m media Stable combustion Temperature: 940CCenter for MicrofibrousSpace Research InstituteMaterials Manufacturing 16. Burner Tests 3: Catalyzed BedAuburn UniversityNH3 plus air thru catalyzedbed, hot apparatus Flame confined to media Temperature: 750 CNH3 plus air thru catalyzedbed, hot apparatus Flame goes into media Temperature: 765 C Center for MicrofibrousSpace Research Institute Materials Manufacturing 17. Burner Tests 4: Catalyzed BedAuburn UniversityNH3 plus air thru catalyzed bed,4.5 m Ni media to preventflame front going into media Stable burning Temperature: 940 CNH3 plus air thru catalyzed bed,4.5 m Ni media to preventflame front going into media Stable burning Temperature: 940 C Temper probe shown Center for MicrofibrousSpace Research Institute Materials Manufacturing 18. S PA C ER ESEA RC HI N ST IT U T EHydrogen Burner for FPSE Auburn UniversityCenter for MicrofibrousSpace Research InstituteMaterials Manufacturing 19. S PA C ER ESEA RC HI N ST IT U T E H2 burner coupled to 35We FPSE Auburn University Qb = 0.544kW (1857.8 BTU/hr)Enough to power up the 35We FPSE, which requires approximately 200W of heat Center for MicrofibrousSpace Research Institute Materials Manufacturing 20. S PA C ER ESEA RC HI N ST IT U T EHydrogen Powered FPSEAuburn University Center for MicrofibrousSpace Research Institute Materials Manufacturing 21. S PA C ER ESEA RC HI N ST IT U T ESummary and ConclusionsAuburn UniversityFavorable conditions for flame stability of combustion of hydrogenreformed from ammonia through a catalyst-impregnated microfibrousporous media were obtained Stable catalytic combustion demonstrated Temperatures of 940C were obtainedFeasibility of ignition and combustion of ammonia depends on: Temperature of the catalyst bed Porosity and pore size of microfibrous media Flow rates of NH3 and airThe microfibrous media can be shaped to conform to the head of aFree-Piston Stirling Engine Multilayer media that controls NOx emissions can also be produced Center for MicrofibrousSpace Research Institute Materials Manufacturing 22. S PA C ER ESEA RC HI N ST IT U T E Summary and ConclusionsAuburn UniversityA simple and safe Hydrogen burner was constructed and tested withinjected air supply and heat recuperation.Based on the findings and feelings of burning Hydrogen with a basicburner, a more sophisticated high efficiency burner can be designed.Demonstrated the feasibility of using a Hydrogen burner usingHydrogen reformed from Ammonia to supply thermal energy to a35We FPSE. Center for MicrofibrousSpace Research Institute Materials Manufacturing 23. S PA C ER ESEA RC HI N ST IT U T EThanks for Your AttentionAuburn University Center for MicrofibrousSpace Research Institute Materials Manufacturing