Hydrogen Storage for Automotive Applications. Hydrogen. Universe most abundant element Odourless and colorless gas. H 2

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1 Hydrogen Storage for Automotive Applications Hydrogen Universe most abundant element Odourless and colorless gas. H 2 Boils at 253 o C. Density is grams/liter. Source Wilkipedia 1 Kg of hydrogen contains the same amount of energy as 2.1 Kg of natural gas or 2.8 Kg of gasoline. Is not toxic and it s combustion generates water. 1

2 Hydrogen Mass Energy Density 40 MJ/Kg H2 CH4 Gasoline 55MJ/Kg 120MJ/Kg Hydrogen volumetric energy density MJ/m Gas 350 bar Gas 700 bar Liquid H2 CH4 Gasoline 2

3 Hydrogen There is, therefore, nothing to fear. As long as the earth is inhabited it will supply the wants of its inhabitants, and there will be no want of either light or heat as long as the productions of the vegetable, mineral or animal kingdoms do not fail us. I believe, then, that when the deposits of coal are exhausted we shall heat and warm ourselves with water. Water will be the coal of the future." Jules Verne The Mysterious Island Chapter 33 Hydrogen Economy Bottleneck DTI acknowledges that..hydrogen storage is the fundamental technical barrier to the more widespread use of hydrogen 3

4 Fuel Cell Requirements Source Fuel Cell Today V Volt=Jule/Culomb=Watt/Amp 0.5 A cm 2 For example a 500cm 2 Cell has around 250 W Output Hundreds are needed to achieve a kw stack Needed for a Vehicle Source Ballard Fuel Cell Car Requirements Typical Example : 75 kw el with 5 to 6 Kg H 2 to cover 300 miles Total tank mass 100 Kg total volume 150 l Typical System requirements kj/mol process ( C) Delivery rate (0-7.2 kg/h) 1.2 kg H 2 refuelling time / min Work in T range 40 to 70 C 4

5 Hyundai FCEV Source Hyundai Source Hyundai Excellent range of 300km and the ability to go into very cold conditions. The vehicle features a 150 liter hydrogen tank and a fuel cell coupled with a 152 volt battery that helps produce 80 kw of power and achieve a speed of up to 90 mph. Motor Max. Output 95kW (129PS, 127 horsepower) Max. Torque 256N-m (26.1kg-m, lb-ft.) Type AC synchronous motor (Honda Mfg.) Honda FCX Fuel Cell Stack Type PEMFC(proton exchange membrane fuel cell, Honda Mfg.) Fuel Type Compressed hydrogen Storage High-pressure hydrogen tank (350atm) TankVolume 171 liters Dimensions (L W H) 4,760 1,865 1,445mm ( inches) Max. Speed 160km/h (100 mph) Energy Storage Lithium Ion Battery Vehicle Range 270 miles Source Honda 5

6 Opel Zafira Fuel cell in Opel Zafira 200 fuel cells in series produce 125 to 200 volts. Top power 94 kw. The power density is 1.6 kw per liter or 0.94 kw per kg. Source GM Tank specs: 4Kg 133KWh 400Km range 200kWh are needed during the hydrolysis, liquefaction and transport. Can keep hydrogen the for 14 days. Source GM DOE Targets for 5 kg. of Hydrogen System 6

7 DOE Targets Kg of H 2 required to make 300miles (500 km.) 5Kg of H 2 ( RT V=56m 3 with167 kwh power eq.) System Weight Kg System Volume litters Should refuel between 2.5 min to 10min Is roughly the equivalent of fitting the volume of a kidney pool of H 2 into a large bin in 2.5 min. Hydrogen Storage Systems Compressed H 2 storage Safety Issues Compressed state of art is 350 bar Kg H 2 /l this is 5Kg in a 180 L Tank Expensive materials needed. Polymer and Carbon fibbers Even at 700 bar 1.38 kwh per litter are achieved. 133 l tank to host 5kg H 2 7

8 Hydrogen Storage Systems Liquid Hydrogen: Cryogenic storage at 253 deg C 30% of the energy content needed to liquefy H 2 Super-insulation Level probe filling line gas extraction 1 to 3% boil off rate liquid extraction filling port Expensive Insulation inner vessel outer vessel supension liquefiedh 2 (-253 C) safety valve gaseous H 2 (+20 C bis +80 C) to engine electrical heater Reversing valve gaseous/liquid shut-off valve Cooling water heat exchanger Hydrogen Storage Systems Hydrogen Adsorption MOFs and C Nanotubes Surface Physisorption Only saturate at 77K H 2 capacity α surface area Very Low density materials MOF: metal organic frame 8

9 Hydrogen Storage Systems Absorption into Metal Hydrides Each Alloy system has a well characterized P vs T system equilibrium. AB 5 and AB 2 systems (ex. LaNi 5 H 6 and Mg 2 NiH 4 ) are very heavy (1.5% to 3.4 % H 2 wt) but have good H 2 density and low decomposition temperatures. (15KJmol -1 to 30 KJ mol -1 ) AlH 3 (10.7% H 2 wt ) decomposes below room T but requires immense pressures to hydride MgH 2 (7.6% H 2 wt)(covalent bond 76 kj/mol) decomposes at temperatures close to 300 C and generates a lot of heat during hydrogenation. 8 Hydrogen Storage Systems 7 6 Value % of weight that is hydrogen H-atoms per cm3 (x ) MgH2 Mg2NiH4 FeTiH2 LaNi5H6 Very different hydrogen weight capacity have the same H 2 volumetric density 9

10 Hydrogen Storage Systems Organic Carriers Hydrogenation and dehydrogenation using a catalyst Hydrogen Storage Systems Complex Hydride Systems: Borohydrides, Alanates and Amides High gravimetric density Regenerate with very high pressures Catalysis Activation 10

11 Catalysis and Bond Destabilization Catalysis and Structure Mg destabilization MgH 2 TEM Bright lines correspond to highly defected areas, this structure provides a network of crystal boundaries allowing hydrogen to diffuse through just a few nanometres of distance. Ni is assumed to deposit there Magnesium Activation 11

12 Solid Hydrogen Storage Cycle Materials Examples: Ni doped MgH 2 6%Wt H C 1-5 bar -75Kjmol TiCl 3 doped NaAlH C 35 to -45 kj mol 5 %H 2 wt 100bar Mg(NH 2 ) 2 + LiH 2 (Catalysis not fully explored) 200C 5 % H 2 wt 100 bar (Leach ammonia in each cycle). Metal Organic Frames 8%Wt at 77 K Solid Hydrogen Storage Examples one shot Materials: (Excluding CH 4, NH 3 and Chemical storage) NaBH 4 Solutions Millennium Cell technology provides wet H 2 at low P Borate expensive regeneration Mg oil slurry Safe H 2 technology: needs water to react MgOH expensive regeneration 12

13 Example Compressed Hydrogen 350 Bar compressed H 2 FC 2002 H 2 Storage Mass kg 1.9 System Mass Kg 51 Gravimetric density % H 2 wt 3.7 Volumetric density kgh 2 /100l 1.5 Pressure bar 350 Example Toyota 2005 Hydride bar tank -22 kj mol-1 H2 Storage Mass kg 7.3 System Mass Kg 420 Gravimetric density % H 2 wt 1.9 Volumetric density kgh 2 /100l

14 Hydrogen There is, therefore, nothing to fear. As long as the earth is inhabited it will supply the wants of its inhabitants, and there will be no want of either light or heat as long as the productions of the vegetable, mineral or animal kingdoms do not fail us. I believe, then, that when the deposits of coal are exhausted we shall heat and warm ourselves with water. Water will be the coal of the future." Jules Verne The Mysterious Island Chapter 33 14