Aluminium as a Fuel

Aluminium

Eamon KeaneCo-Authors: Dr David Browne & Dr Alun Carr

University College Dublin 1

Water + Aluminium-Gallium Fuel Pellets

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Prof. Jerry Woodall, Purdue University Claims:

• Energy efficient – 50% recycling efficiency• Environmentally sound• Cheap – equivalent to $3/gallon for petrol• Scalable (enough gallium for 1 billion cars)• Reaction is: • Gallium is inert in the reaction• Can use variable wind power for electrolysis

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2.2L=1L

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2 2 332 2Al O Al O

energy trapped

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Water+ =

Hydrogen on Demand

Aluminium Hydroxide

+

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Aluminium Fuel Cycle Inputs

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Aluminium Hydroxide Alumina

Calcining Smelting

Aluminium Fuel Cycle

13.5% energy efficiency, not 50% 8

Energy and CO2 Per Km Travelled

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Pourbaix Diagram

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33um

Pure gallium in grain boundaries, β phase

α phase: solid solution

Aluminium-Gallium Phase Diagram

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Fuel Pellet

The Reaction

Gallium is not inert in the reaction12

Element E°V (V)

Lithium -3.04

Aluminium -1.66

Gallium -0.56

Hydrogen 0

Gold +0.80

Standard Electrode Potential

Large difference, galvanic corrosion expected.

Reaction Mechanism

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Surface After Reaction

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Gallium Production

Enough for ~ 30,000 cars – not 1 billion!

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Elements with very low worldwide 2008 production (Up to ~ 10,000 tons)

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Aluminium as a Fuel

Aluminium

Any Questions?

Renewable ≠ Green

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