Environmental Geochemistry III. Aleš Bajer

Transcription

1 III. Aleš Bajer Tento projekt je spolufinancován Evropským sociálním fondem a Státním rozpočtem ČR InoBio CZ.1.07/2.2.00/

2 Resources Mineral Resources and Mining Fossil and Uranium Fuels Alternative Energy Resources

3 Mineral Resources and Mining - 2 categories: metallic and nonmetalic rocks and minerals - place with enrichment of one or more mineral = MINERAL DEPOSIT - deposit of metal-bearing minerals that can be mined at a profit = ORE - Ore forms by magmatic,hydrothermal, sedimentary, weathering and metamorphic processes -Mineral resources are mined in two ways: a) OPEN PIT MINE (surface) b) TUNNEL MINE (underground)

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5 HOW ORE FORMS? - By magmatic processes: crystal settling - solid minerals are denser than liquid magma. - crystals sink to the bottom of a magma chamber - in this way heavy metals (platinum, chromium ) forms

6 HOW ORE FORMS? - by magmatic processes: pegmatites - water-rich granitic magma causes solidification of large crystals - rock with extremely coarse-grained minerals is called pegmatite - extreme size of particular crystals of feldspar, quartz and mica (10 x 5 m) - certain rare elements also concentrate in pegmatites (beryl, lepidolite, tourmaline, )

7 HOW ORE FORMS? Hydrothermal ore deposits are results of precipitating from hot water solution. Fluorite, Galena, Barite

8 HOW ORE FORMS? Submarine hydrothermal ore deposits Precipitate from circulating seawater near the mid-oceanic ridge.

9 HOW ORE FORMS? - by sedimentary processes: sedimentary sorting -Placer deposits from where water currents slow down and deposit heavy minerals (gold)

10 MINERAL RESERVES - may increase in two ways: a) discovery new mineral deposits b) by increasing a price or improving a technology of extraction noneconomic mineral deposits change into profitable ones Changes in the reserves of some types of ore

11 MINERAL RESERVES - 4 nations the United States, Germany, Japan and the former Soviet Union consume about 75% of used metals, but their population is only 15% of world population. (China 10% - 16%)

12 MINERAL RESERVES - predictions of future supplies of selected materials use in industry

13 ENERGY RESOURCES Energy is the basic condition for our current western life style. - things like hot water, air condition, car, fresh kiwi in the middle of winter is matter of course for this life style all depend on plentiful cheap energy What are energy resources? - Fossil Fuels (coal, petroleum and natural gass) - Uranium Fuels - Alternative resources Fossil and Uranium Fuels influence on environment negatively. Recently we put the accent on alternative resource searching and saving energy.

14 ENERGY RESOURCES Source of energy production Use of energy in particular sectors

15 COAL - formed from decayed remains of plants in swaps peat by increasing temperature and pressure - there are various types of coal (lignite, brown coal, black coal, antracite) Coal mining: a) underground coal-mining causes subsidence and colaps surface b) opencast coal-mining - causes extensive devastation of land - changes on landscape surface and water drainage Use: electricity production (power station) = 60% steel factory =30% steam factory =10% In the Czech Rep. the coal is used for individual house heating.

16 COAL negative results: - pollution (acid rain, carbon dioxide emission, thermal pollution in water - electromagnetic radiation is escaping at transmission

17 COAL Formation of coal

18 COAL Areas in USA where attractive coal deposits are found

19 PETROLEUM (OIL) - formed from organic matter in shallow coastal waters during rising temperature and pressure - convert the organic matter to liquid petroleum - Petroleum is dispersed in the rock oil traps Driling and pumping causes oil spills and land degradation Transport (pipeline, tanker): oil spills Refining process causes: - air and water pollution Use: gasoline burning causes air pollution (CO2, NOX, Pb)

20 PETROLEUM (OIL) Formation of an oil reservoir

21 PETROLEUM (OIL) Products of rafinery treat Oil pollution

22 PETROLEUM Four basic types of oil traps

23 PETROLEUM Global oil reserves and oil consumption Consumption by country: USA (20 mil), China (7,5 mil), Japan (5 mil), Russia (2,8 mil), India (2,7 mil), Germany (2,5), CZ ( ) EU (15 mil)

24 NATURAL GAS - similar using like petroleum, but causes less pollution - less world supplies and higher price - the leading producer is Russia (problematic supplying) - CZ 10 years ago almost every individual house heating was using natural gas x now incresing price of natural gas = return to coal (increasing of local pollution)

25 URANIUM AND ATOMIC ENERGY spontaneous emission of radiation from an element radioactivity - nuclear power plants use nuclear fission - fuel is isotope of uranium U-235 (not spontaneous) - natural uranium contains only 1% U increasing of U-235 is necessary for using fuel - used in the form of small pellets

26 URANIUM AND ATOMIC ENERGY

27 URANIUM AND ATOMIC ENERGY Radioactive Wastes - after mining the material is radioactive - during enrichment radioactive wastes are produced - fission process produces radioactive waste (it is more radioactive than original U-235) - no satisfactory sollution has been found yet (no permanent storage exists) - at present there are short-term (till 50 years) and middle-term ( years) storing - nowdays pellets are testing to be reprocessed to recover U lifetime of nuclear power plant is about 50 years there is question what to do with it?

28 URANIUM AND ATOMIC ENERGY The nuclear fuel cycle Temporary storage Permanent storga

29 URANIUM AND ATOMIC ENERGY Radioactive accident -generally people are scared about accident at nuclear power plants - there were two big accident in past 1979 USA, Pensylvania, Three Mile Island nuclear power plant 1986 former Soviet Union, Chernobyl (Ukraine) - These accidents influenced on large area Chernobyl half of Europe - The accidents was caused by human failures - Control warning systems were off In my opinion atomic energy is alternative for fossil fuels under the concrete conditions.

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31 ENERGY CONSERVATION (SAVING) 42,5% energy waste could be avoided with conservation

32 ENERGY CONSERVATION - using technologies with higher efficiency

33 ALTERNATIVE ENERGY RESOURCES -The first opportunity is consistent energy discipline in household, industry and transportation - SOLAR ENERGY - passive solar heating

34 ALTERNATIVE ENERGY RESOURCES SOLAR ENERGY -active solar heating (solar collectors) trap the solar energy and use it to heat water there are a few problems: - it is more expensive - it works only during the sunlight period - it wants too much space for to be productivity for example: generating 100 mil. Watts = energy for people it needs 3 km2 of solar panels In spite of all of this solar energy has the greatest potential of all alternative energy resources

35 ALTERNATIVE ENERGY RESOURCES SOLAR ENERGY Boom of solar energy in CZ causes higher price of el. Energy Weakness: solar energy needs to be doubled

36 ALTERNATIVE ENERGY RESOURCES Hydroelectric Energy - use the energy of water droping down-ward throught the dam - produces almost of 20% of the world s electricity - hydroenergetic plants do not pollute the water and do not disturb hydrologic cycle - dams and hydropower systems radically alter stream ecosystem - today huge hydroelectric dam project are building in China, Brasil, India, Nepal and Canada - all of these project influence on environment - the biggest producer is China - in the Czech Rep. the hydroelectric sites are limited. - potential is much lower than in Austria or Switzerland

37 ALTERNATIVE ENERGY RESOURCES Geothermal Energy - energy extracted from the earth s heat - there are two forms: - dry heat (transformation from hot rock into medium) - wet heat (hot spring water is using) - typical for place with high geothermal activity (vulcanic activity, earthquake, hot springs) - in the Czech Rep. geothermal energy is using only locally - unlike Slovak Rep. and Hungary where it is more common

38 ALTERNATIVE ENERGY RESOURCES Geothermal Energy Schematic view of dry geothermal energy plant Steam escapes from hot water heated by deep hot rock

39 ALTERNATIVE ENERGY RESOURCES Wind Energy -the specific form of solar energy sun s heat creates wind - it can be use in places with strong and standy wind - windmills has been used to pump water since Middle Age - today wind farms are generating electricity - they are using especilly in California and Hawaii - in the Czech Rep. the using of this energy is starting to be discussed. Places with good wind conditions were selected. - wind energy is discussed in the view of noice and view pollution.

40 ALTERNATIVE ENERGY RESOURCES Biomass Energy -the main resource (wood) of heating in past - today it is used for local burning stoves - produces so much smoke and pollution especially in winter - today there are special plant products for production of bioenergy - it is prefered as alternative energy resources in EU - large agriculture sites are using for these plants Energy from the seas - tidal energy: are not always economical, there are some projects but not realy using - wave energy: there are a few wave generators in Northern Ireland and England

41 ALTERNATIVE ENERGY RESOURCES Energy for future? - nuclear fussion: the energy of stars such as the sun produces when H combine to form He - huge amount of energy 1 g = 9400 l of gasoline - the process is known in the view of theory - but not prepared for realization in the view of technology now! Conclusion However there are still quite enough of fossill fuel reserves it is important to increase using of alternative energy resources. Energy saving (decreasing of energy use) unlike wasting can increase the amount of available energy in the quickest and least expensive way.