Rare Earth Mineral Exhaustion.ppt

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					Rare Earth Mineral
   Exhaustion
 The Example of Platinum
  1. How much is in the Crust?
• Ask the geologists and they claim, from a
  few source surveys that the crust has a
  total of 67.3 Giga Grams of platinum
• Of that 30 has already been mined leaving
  behind a total resource of 37 Gg
 2. What is the recovery efficiency

• Data shows that its 89%
• Recoverable Pt is now 37 Gg x .89 = 32.9
 3. How much platinum is needed
         per fuel Cell
• 0.4 g per KW generated
• Average vehicle power is 75 KW
• 0.4 x 75 = 30 g of Pt needed per vehicle
4. What is the lifetime of a fuel cell

• 10 years
• So need 30g of replacement Pt every 10
  years per fuel cell
   5. What about recycling of fuel
       cells and Pt recovery
• About 50% of Pt can be recovered via a
  recycled fuel cell.
• So, dig up Pt and put 30g in a fuel cell 
  10 years later get 15g to put back into
  another fuel cell to go along with 15g of
  newly mined Pt
 6. How much Pt resource goes to
           fuel cells?
• Other uses of Pt: jewelry, fuel cells for
  stationary power, catalytic converters for
  clean air (1-5 g) per vehicle, industrial
  processes.
• Assume 1/3 of Pt goes to the above
• This leaves us with 2/3 of 32.9 or 22 Giga
  grams of Pt for fuel cells
      7. Pick a starting point
• In the year 1 we make 50 million fuel cells
  for 50 million vehicles
• This uses 1.5 Gg of the available 22 Gg of
  the Pt reservoir
• Every year we make 50 million new
  vehicles and we continue this until we
  have ramped up to 500 million vehicles
• How long can this be sustained?
       The Pt Depletion Chart
Year         Gg/year   Remaining
1            1.5       22-1.5 =20.5
2            1.5       19
3            1.5       17.5
4            1.5       16
5            1.5       14.5
6            1.5       13
7            1.5       11.5
8            1.5       10
9            1.5       8.5
10           1.5       7.0
       Now we recycle
Year     Gg/per year   Pt Left
11       (.75) +.75    7-.75 = 6.25
12       .75           5.5
13       .75           4.75
14       .75           4
15       .75           3.25
16       .75           2.50
17       .75           1.75
18       .75           1.0
19       .75           .25 and done

				
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posted:7/19/2012
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