Antonio Valero

1. PHYSICAL GEONOMICS: COMBINING THE EXERGY AND HUBBERT PEAK ANALYSIS FOR PREDICTING MINERAL RESOURCES DEPLETION Antonio Valero July 6, 2009 ISDR Utrecht Centre of Research for Energy Resources and Consumption

2. How fast is humankind degrading the mineral capital on earth?… The exergy countdown: prediction tool for assessing the future state of the mineral capital on earth

3. We want to demonstrate that the irreversibility concept, through the exergy analysis is able to predict the future mineral consumption in the world…

4. EXERGY COUNTDOWN OF THE WORLD’S MINERAL RESERVES By 2070, the peak of production of all mineral commodities in the world will have been reached.

5. Why exergy analysis? The economical evaluation of natural resources rarely take into account physical characteristics that make them valuable: a particular composition and a specific concentration. (Scarcity increases but prices do not!) Physical evaluations of mineral resources in terms of mass (tonnage) and concentration (grade) avoid comparison among minerals. But they can be evaluated from a thermodynamic point of view with a single property in terms of exergy.

6. Why exergy analysis? The exergy of a system measures the level of departure from the environment. => quality. All materials have a definable and calculable exergy content with respect to a defined reference environment. Exergy is the maximum amount of work that may be theoretically be performed by bringing a resource into equilibrium with its surroundings by a sequence of reversible processes.

7. Why exergy analysis? • Advantages • Objective • Transparent • Aggregation / Dissagregation capacity • Universal units: energy units • Monetary evaluation easy through energy prices • It is a physical property, more than an indicator. “The entropy law itself emerges as the most economic in nature of all natural laws […] and this law is the basis of the economy of life at all levels” Georgescu-Roegen. The Entropy Law and the Economic Process 1971

8. A mineral deposit is a rarity in the earth’s crust. Only when a combination of natural processes has worked together to produce an enrichment, is an ore to be found. These complex process operate very slowly compared with the life-span of humans. The exergoecological approach measures the exergy required to reproduce a mineral deposit

9. The value of a mineral may be determined by its composition, concentration and quantity. All three are accounted with exergy. The minimum theoretical work that nature should invest to provide minerals at a specific composition from a degraded earth is equal to the standard chemical exergy: The exergy of a mineral deposit

10. The minimum theoretical work needed to concentrate a substance from an ideal mixture of two components is given by the concentation exergy: The exergy of a mineral deposit

11. Actual exergy Thermodynamic exergy • The exergy cost of a mineral deposit • Exergy accounts for a minimum, however the real processes designed by man are far from ideal conditions. We would ignore technological limits which are much more costly!

12. The exergy cost of a mineral deposit • We must include the real physical unit costs (unit exergy replacement costs) in the thermodynamic evaluation of resources. • They are defined as the relationship between the energy invested in the real process of obtaining the resource and the minimum energy required if the process were reversible. kc and kch are x10 or x100 b. • The real exergy (exergy cost) would be then: • Unit exergy costs are a function of technology and vary with time. => Data from Botero 2000.

13. THE HUBBERT PEAK • The production of fossil fuels follow bell-shaped curves (Hubbert 1956). • Satisfactorily applied to minerals where concentration factor is not important (liquid fuels). • It can be fitted to minerals in terms of exergy -> accounts also for concentration and composition. Q=available resources P=extraction of minerals

14. Three ingredients for assessing mineral exergy evolution throughout mining history: • Production trends. • Reserves. • Ore grade trends. • Historical Statistics from BGS and USGS

15. Non fuel minerals • 3 minerals account for 93% of the exergy cost consumption. • But also Mn, Zn, Ni, Zr, Pb, Cr, U, Sn and Au. • Each year we are degrading 1,3 Gtoe (50% exergy consumption of natural gas).

16. Non fuel minerals • Most depleted commodities are Hg (92%); Ag (79%); Au (75%); Sn (75%), As (75%); Pb (72%); Sb (72%). • Least depleted: Cs, Th, REE, I, V, K, PGM, Al, Ta, Co, Nb (<20%) • Important minerals: Fe (28%); Al (15%); Cu (50%).

17. Non fuel minerals. The Hubbert peak Considering reserve base • Fe: 2068 • Al: 2057 • Cu: 2024 Values in ktoe

18. Fuel minerals

19. Values in Mtoe Fuel minerals. The Hubbert peak Considering proven reserves • Coal: 2060; as opposed to EWG 2007 (2025). • Nat. Gas: 2023; as predicted by Bentley 2002. • Oil: 2008; as predicted by Hatfield 1997, Kerr 1998 or Campbell and Laherre 1998

20. Resources prices depend on different factors such as demand, political and social aspects, speculation... • But the limiting factor that will determine the general trend is the availability of the resource. • If demand continues to increase and no very large oil deposits are found, the price of oil will presumably increase in the future.

21. EXERGY COUNTDOWN OF WORLD’S MINERAL RESERVES The exergy countdown could become a powerful tool with important consequences in the future management of resouces 2010 2040

22. The Exergy countdown The same analysis considering 2 x proven reserves (fuels) and 2 xreserve base (non fuel minerals) • The peak only moves to the right around 15 to 30 years!

23. REFLECTIONS • There are many places in the world unexplored. Nevertheless, these preliminary results are pointing out that the rate of mineral extraction in just one century has been excessive. => The rate of discovery may not compensate the exponential increase. • Many commodities are suffering scarcity problems. Substitution may help, but only as long as other mineral resources are available. • Future consumption scenarios such as IPCC 2000 assume rates of consumption that even exceed the current reserves. Concern about climate change or loss of biodiversity. Scarcity of resources? • The consumption of increasingly scarce minerals implies important environmental problems: consumption of huge amounts of water, energy and the production of waste rock.

24. REFLECTIONS • Mankind has put neither energy nor mass limits to the extraction of minerals. • It is not enough to establish conventional measures of energy efficiency, renewables, CO2 sequestration… A drastic limitation in the extraction of minerals is required.

25. CONCLUSIONS • This paper demonstrates that Thermodynamics can play a key role in the management of natural resources and in the awareness that we are quickly approaching a degraded planet. • The latter will never be determined exactly, but it can be gradually better delimited just by applying the second law evolutionary theories.

26. PERSPECTIVES • A new physical accounting tool could be developed: • Physical Geonomics • (raw materials economy) • It would account for all physical changes in the mineral stock on earth (raw and recycled materials), establishing the basis for an appropriate management of the resources. THE EXERGOECOLOGICAL APPROACH COULD CONSTITUTE A UNIVERSAL AND TRANSPARENT TOOL FOR ASSESSING NATURAL RESOURCES AND HELPING DECISION MAKERS FOR AN APPROPRIATE MANAGEMENT OF THE EARTH’S PHYSICAL STOCK

27. CONCLUSIONS • It is not the same to perceive that time passes than to have a watch and measure exactly how many minutes are left until the end of the day. The aim of this study is to pave the way to precisely account the time to reach a degraded planet.

28. THANK YOU VERY MUCH FOR YOUR ATTENTION