Hydrogen Storage Materials Basic Properties and First Safety Studies - PowerPoint PPT Presentation

Hydrogen Storage Materials Basic Properties and First Safety Studies Maximilian Fichtner Institute for Nanotechnology Department of Nanostructured Materials Karlsruhe Research Center 1 | M. Fichtner | ESHSS | 30. July 2007

Content � Introduction / Problem � Principles of hydrogen storage Physisorption and chemisorption materials � Safety studies with nanoscale hydride � Summary 2 | M. Fichtner | ESHSS | 30. July 2007

Permanent Issue: Energy storage in vehicles The first cars were electric vehicles (1885) ! Speed record: Jenatzy´s world record vehicle „La Jamais Contente“ (1899) reached 106 km/h 3 | M. Fichtner | ESHSS | 30. July 2007

Fossil fuels on a historical timescale 4 | M. Fichtner | ESHSS | 30. July 2007

Why Hydrogen? Liquid fuels can store more energy per volume and mass compared to H 2 storage-systems (incl. Tank, Valves etc.). Energy Storage in H 2 is by a factor 8 better than the best batteries. 5 | M. Fichtner | ESHSS | 30. July 2007

State of the art in hydrogen storage technologies 2007 Current Cost Estimates (based on 500,000 units ) 700 bar 350 bar Liquid H2 Complex Hydride Chemical Hydride $0 $5 $10 $15 $20 2015 target $/kWh 2010 target * source: G. Thomas, US-DoE, 2007 (priv. comm.) 6 | M. Fichtner | ESHSS | 30. July 2007

Physical limits for H storage volumetric storage density Mean distance between H 2 molecules and H atoms 7 | M. Fichtner | ESHSS | 30. July 2007

Binding principles for hydrogen Physisorption Chemisorption Weak binding of H 2 –molecules at the Splitting of H 2 molecule surface (long range Van der Waals Chemical bonding of H atoms in host interactions) lattice 8 | M. Fichtner | ESHSS | 30. July 2007

Energy Diagram for Physisorption/Chemisorption E Pot 2 H E a Desorb E Diss E act E a chemisorb z solid H 2 E phys E chem Physisorption of H 2 Chemisorption of 2 H 9 | M. Fichtner | ESHSS | 30. July 2007

Physisorption Materials: Carbon-nanotubes? First reports about high H-contents were most probably experimental errors ! M. Hirscher, 2005 10 | M. Fichtner | ESHSS | 30. July 2007

Examples Physisorption Materials: Metal-organic frameworks (MOFs)! Yaghi et al., Angew. Chem. Int . Ed. (2005) ZnO clusters Self assembled structures organic linkers (carboxylates) 11 | M. Fichtner | ESHSS | 30. July 2007

MOFs : H storage capacity 7.5 wt% H @ 77 K, 40 bar Yaghi et al., JACS, 2006 12 | M. Fichtner | ESHSS | 30. July 2007

Development of low / medium temperature solid storage materials for hydrogen M. Fichtner, Adv. Eng. Mater. 6 (2005) 432 13 | M. Fichtner | ESHSS | 30. July 2007

Today´s systems: Nanocomposites on hydride basis Nanoscale mixture of: Dopants H-Carrier TM Basis Complex light metal hydrides: & Nanoscale Alanates M(AlH 4 ) Boranates M(BH 4 ) Amides M(NH 2 ) The nanocomposite is the actual storage material. Compared to pure H-carrier: considerably improved H exchange properties. 14 | M. Fichtner | ESHSS | 30. July 2007

Sodium alanate, NaAlH 4 , as hydrogen carrier Bogdanovic ć 1997 (MPI-KF): “ Ti-doped alkali metal aluminium hydrides as potential novel reversible hydrogen storage materials“ (JALCOM 97) ~ 4.5 wt.% H C.M. Jensen et al. , J. Appl. Phys. A 72 (2001) 213 – 219 ~ 4.5 wt.% H reversible reversible @ 80 – @ 80 – 120 °C 120 °C Temp p 3 NaH + Al + 3/2 H 3 NaH + Al + 3/2 H 2 2 Na 3 AlH 6 + 2 Al + 3 H 2 Na 3 AlH 6 + 2 Al + 3 H 2 3 NaAlH 4 3 NaAlH 4 15 | M. Fichtner | ESHSS | 30. July 2007

Safety Issues … 16 | M. Fichtner | ESHSS | 30. July 2007

Physisorption Materials / Safety issues Combustion energy of: Low temperature (77 K) ! Hydrogen No immediate release of stored amount H 2 + Sorbent (carbon, MOF) Sorbent combustible ? 17 | M. Fichtner | ESHSS | 30. July 2007

Chemisorption Materials (Hydrides) / Safety issues Combustion energy of: No immediate release of stored amount H 2 hydrogen + Flame rate metal Self ignition in contact with air / water ? General recommendation: Avoid dust explosions with finely dispersed solid storage materials! 18 | M. Fichtner | ESHSS | 30. July 2007

Methods to extinguish a metal hydride fire Dilute burning powder with inert material (*dry* sand, NaCl) Use a metal fire extinguisher (NaCl + melting polymer � � � � crust) Interrupt air contact Cool it down with liquid N 2 Never use ! � � Laboratory ! � � Water CO 2 19 | M. Fichtner | ESHSS | 30. July 2007

Hydrogen Safety Scoping Tests With Hydride Based Nanocomposite 20 | M. Fichtner | ESHSS | 30. July 2007

Largest (public) research activity on hydrogen in Germany 50 Researchers in 6 institutes Working on: 21 | M. Fichtner | ESHSS | 30. July 2007

Hydrogen Safety Center 22 | M. Fichtner | ESHSS | 30. July 2007

Question: What can we expect if a device filled with a nanoscale complex hydride � is at operating conditions (p,T), and then � the shell breaks and the material is ejected into the environment ? 23 | M. Fichtner | ESHSS | 30. July 2007

Principle setup SS-Tube filled with Ti-doped NaAlH 4 Burst Disk Operation: T � � � � 130 °C P rises Disk bursts at p = 10 bar Material shot into various environments 24 | M. Fichtner | ESHSS | 30. July 2007

Small scale device failure test 4 tests were performed with ca. 100 ml Ti-doped SAH at typical operation temperatures (130°C) and pressures (10 bar) of the material: 1. Reproduction of earlier experiment (ejection in dry air) 2. Spark ignition of hydrogen-dust cloud 3. Ejection into water shower 4. Comparative test with equimolar amount of pure hydrogen 25 | M. Fichtner | ESHSS | 30. July 2007

Basic Equipment for Experiments: ► High speed camera, Speed Cam Visario 1500 ► Infrared camera, Thermovision A40 ► Digital Video camera, DCR-TRV30E ► Digital camera, Camedia C-1 ► Control unit, LABJACK U12 ► Transient recorder, Krenz PSO 9080 ► Fast sound level meter, RO 1350 ► Fast pressure sensors ► Fast T-sensors 26 | M. Fichtner | ESHSS | 30. July 2007

Reactor Setup Electrodes for spark ignition 27 | M. Fichtner | ESHSS | 30. July 2007

Experiment 1: Shot in dry air 28 | M. Fichtner | ESHSS | 30. July 2007

Result experiment 1: Reproduction of „Dry Experiment“ from 2005 29 | M. Fichtner | ESHSS | 30. July 2007

Experiment 2: Spark Ignition / IR camera 0.2 sec 0.6 sec Burning hydrogen ignites dust cloud. Relatively slow combustion 30 | M. Fichtner | ESHSS | 30. July 2007

Setup experiment 3: Water shower 31 | M. Fichtner | ESHSS | 30. July 2007

HighSpeed images of rain shower experiment Ignition by water droplets 30 ms 60 ms Flame 240 ms 560 ms 32 | M. Fichtner | ESHSS | 30. July 2007

Experiment 4: Equimolar amount of pure H 2 + spark ignition Small flame but very fast combustion (approx. 70 ms) � � � turbulent deflagration � 33 | M. Fichtner | ESHSS | 30. July 2007

Soundlevels, first millisecond Pure hydrogen opening of burst disc reproduction 2005 Rain Shower Spark ignition 34 | M. Fichtner | ESHSS | 30. July 2007

Summary Solid storage materials have the physical potential to reach the goals set for hydrogen storage � � t.b.d. � � First safety tests with nanocomposite: • Dry air experiment was reproduced. • Hydrogen/dust cloud with sparks � � � Ignition. High T in the cloud � • Water shower � � � Self-ignition @ several places. Lower T in the cloud. � • Experiment 2 with equimolar amount of pure hydrogen (and no hydride) was much more aggressive � � � � explosion ! • 2., and 3.: flame-thrower like events, no explosion ∆ p < 5 mbar @ 1 m distance ∆ ∆ ∆ • • Heat of reaction is damped by the presence of water • Combustion of powder/H 2 cloud > propagation of flame 10x slower than with pure H 2 • More energy involved, but much slower propagation of the flame � � reduced � � violence. 35 | M. Fichtner | ESHSS | 30. July 2007

Acknowledgements Financial support by: Helmholtz Initative „FuncHy“ EU-IP „NESSHy“ EU-IP „StorHy“ EU-RTN „COSY“ Forschungsallianz Brennstoffzelle BW 36 | M. Fichtner | ESHSS | 30. July 2007

People at the INT… Krzysztof Chłopek Christoph Frommen Nobuko Hanada Johannes Kostka Aline Léon Wiebke Lohstroh Ravimohan Prasad Stephan Wetterauer Oleg Zabara Maximilian Fichtner Nanostructured Materials Olaf Fuhr Cluster Chemistry Olaf Hübner Theoretical Chemistry 37 | M. Fichtner | ESHSS | 30. July 2007

Thank Thank Thank Thank you you you for you for for for your your your your PATIENCE 38 | M. Fichtner | ESHSS | 30. July 2007