1. Rare Earth Mineral Exhaustion The Example of Platinum

2. 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

3. 2. What is the recovery efficiency Data shows that its 89% Recoverable Pt is now 37 Gg x.89 = 32.9

4. 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

5. 4. What is the lifetime of a fuel cell 10 years So need 30g of replacement Pt every 10 years per fuel cell

6. 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

7. 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

8. 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?

9. The Pt Depletion Chart YearGg/yearRemaining 11.522-1.5 =20.5 21.519 31.517.5 41.516 51.514.5 61.513 71.511.5 81.510 91.58.5 101.57.0

10. Now we recycle YearGg/per yearPt Left 11(.75) +.757-.75 = 6.25 12.755.5 13.754.75 14.754 15.753.25 16.752.50 17.751.75 18.751.0 19.75.25 and done