Matériaux pour le stockage réversible de l hydrogène à température ambiante

Transcription

1 1/23 Matériaux pour le stockage réversible de l hydrogène à température ambiante Fermin Cuevas Institut de Chimie et des Matériaux Paris Est CNRS / Université Paris Est Responsable axe-stophe, GdR HySPàC

2 Outline 2/23 Outline Introduction to hydrogen storage methods & materials Metal hydrides as RT stores Practical applications Conclusions

3 Introduction to H-storage The hydrogen chain Energy Source Production Storage Use Reformer Mobile Stationary Electrolyser Fuel Cell (δt) Electric Grid Isolated sites Hydrogen storage: time/space coupling of H 2 production and use 3/23

4 Introduction to H-storage 4/23 Hydrogen storage : physical means High pressure (H 2 -gas) Composite tank Pressure range P bar Capacity 5-6 wt.%; 40 g/dm 3 Low temperature (H 2 -liquid) T= 21 K Insulating tank Capacity 6 wt.%; 35 g/dm 3

5 Introduction to H-storage 5/23 Hydrogen storage : chemical means - solids Molecular hydrogen Atomic hydrogen H H Adsorbed on solids Porous materials Weak-bond: H < 10 kj/mol Zeolites, Carbon, MOFs Absorbed in solids Metallic, covalent or ionic hydrides Strong-bond: 20 < H < 200 kj/mol LaNi 5 H 6, MgH 2, LiBH 4, NH 3 BH 3

6 Introduction to H-storage 6/23 Advantages of hydrogen storage in hydrides Operating, in some cases, at normal P and T conditions Compactness Gas Liquid Hydrides P (bar) T (K) 1 bar 300 K 350 bar 300 K 700 bar 300 K 1 bar 20 K ~ 1 bar ~ 300 K d d (nm) Cv (g H /L) ~120 Safety: low pressure, moderate T, self-regulating reaction

7 Introduction to H-storage Gravimetric and volumetric hydrogen capacities Metal hydrides (TiFeH 2, LaNi 5 H 6 ) Ionic hydrides (MgH 2 ) Complex hydrides (NaAlH 4, LiBH 4 ) Züttel et al. Phil. Trans. R. Soc. A 368 (2010) /23

8 10 8 Introduction to H-storage Operation temperature: a key role LiBH 4 MgH 2 Mass Capacity (wt.%) TiMn 2 NaAlH 4 Material System MgH Temperature ( C) 8/23

9 9/23 Metal hydrides as RT stores

10 Metal hydrides as RT stores 10/23 Basics of hydrogen storage in metals + M(s) + x /2 H 2 (g) Q MH x (s) P H2 Reversible reaction tuned by P and T Absorption exothermic. Desorption endothermic ( Q) M H metallic bonding The metal lattice expands upon absorption ( V/V 20%)

11 Metal hydrides as RT stores 11/23 Reversibility: P-C isotherm β H 2 abs +β H 2 des

12 Metal hydrides as RT stores Ln(P H2 ) 12/23 Dependence of Plateau Pressure with Temperature T 3 > T 2 > T 1 T 3 T 2 + T 1 max C (H/M) min P p increases with temperature: self-regulating reaction

13 Metal hydrides as RT stores LaNi 5 A large variety of compound families c TiMn 2 b TiFe AB n a V A Rare earth or early-transition metal, B late-transition metal 13/23

14 Thermodynamics can be adapted to application Metal hydrides as RT stores Tuning of hydride stability through chemical substitution Plateau pressure (bar) 1 0,1 LaNi 5 Al 0.1 Co 0.75 LaNi 5-x M x 25 C Co 2 Al 0.3 Al 0.3 Co 0.75 Mn 0.4 Mn 0.4 Co 0.75 Mn 0.4 Al 0.3 Mn 0.4 Al 0.3 Co , Cell volume (Å 3 ) Cuevas et al. Appl. Phys. A, 72 (2001) /23

15 Easy activation, handling & thermal effects Pression H 2 (bar) Metal hydrides as RT stores Temps (secondes) T ( C) 15/23

16 Metal hydrides as RT stores ActHyMet-project (PE CNRS) ActHyMet (Activation of Metal Hydride): In-situ microscopic analysis of mechanical and thermal effects during hydride activation CCD/IR Camera t = 230 t = 272 t = 315 Reaction chamber Project leader: Anne Maynadier, FEMTO-ST 500 m 16/23

17 17/23 Practical applications

18 Practical applications 18/23 Nomadic application: mobile Korean phone Kim et al. Appl. Energy 134 (2014) 382 Hydrogen storage properties Compound-type AB 5 Composition Mm (Ni, Mn, Co) 5 Alloy capacity Tank capacity P absorption P desorption Charging time 1.5 wt% Mass: 1.08 wt% Vol: 46 g/l 10 bar max <1 bar (regulator) 40 min (in air) H-storage content 4.1 NL (0.37 g)

19 Practical applications Minibar for Switzerland trains Operational since 2014 Hydrogen storage properties Compound-type AB 5 Composition - Alloy capacity - Tank capacity P absorption P desorption Charging time Mass: 0.66 wt% - 10 bar max 2 bar 2 h (with cooling) H-storage content 935 NL (84 g) Swiss railway company, SBB-CFF 19/23

20 Practical applications 20/23 German submarine U212 (HDW) Operational since 2005 Propulsion: PAC PEM Siemens Hydrogen storage properties Compound-type AB 2 Composition (Ti,Zr)(Mn,V,Fe,Cr) 2 (GfE Hydralloy ) Alloy capacity ~ 1.6 wt % Tank capacity P absorption P desorption Charging time - H-storage content Mass: 1.25 wt% Vol: 46 g/l ~ 10 bar ~ 5 bar 610 Nm 3 (55 kg)

21 Practical applications 21/23 Electricity and heat for Japanese resort Operational since 03/2016 Summer Winter Hydrogen storage properties Compound-type AB 5 P absorption 8 bar max H-storage content 270 Nm 3 (24 kg)

22 Conclusions 22/23 Conclusions Despite their low gravimetric capacity (< 3 wt.%), metal hydrides remain as benchmark of RT storage materials: - Adaptable thermodynamic properties to usage - High volumetric capacities (reduced footprint) - Safe material and system handling Improvement of metal hydride properties is still needed: - Capacity increase: substitution by light elements (e.g. Mg,Ti, Y) - Surface engineering: activation / resistance to impurities - Cost reduction: use of abundant/non critical metals Long-term fundamental research is required to make ionic/covalent hydrides reversible at RT

23 23/23 Acknowledgements Axe STOPHE