Mrs sealy apes
This presentation is the property of its rightful owner.
Sponsored Links
1 / 111

Mrs. Sealy APES PowerPoint PPT Presentation


  • 159 Views
  • Uploaded on
  • Presentation posted in: General

Ch. 14 Notes Energy. Mrs. Sealy APES. I. Mining Law of 1872 – encouraged mineral exploration and mining. 1. First declare your belief that minerals on the land. Then spend $500 in improvements, pay $100 per year and the land is yours

Download Presentation

Mrs. Sealy APES

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Mrs sealy apes

Ch. 14 Notes

Energy

Mrs. Sealy

APES


I mining law of 1872 encouraged mineral exploration and mining

I.Mining Law of 1872 – encouraged mineral exploration and mining.

  • 1.First declare your belief that minerals on the land. Then spend $500 in improvements, pay $100 per year and the land is yours

  • 2.Domestic and foreign companies take out $2-$3 billion/ year

  • 3.Allows corporations and individuals to claim ownership of U.S. public lands.

  • 4.Leads to exploitation of land and mineral resources.

http://seattlepi.nwsource.com/specials/mining/26875_mine11.shtml


Mrs sealy apes

  • "This archaic, 132-year-old law permits mining companies to gouge billions of dollars worth of minerals from public lands, without paying one red cent to the real owners, the American people.  And, these same companies often leave the unsuspecting taxpayers with the bill for the billions of dollars required to clean up the environmental mess left behind."

  • -- Senator Dale Bumpers (D-AR, retired)


Nature and formation of mineral resources

Nature and Formation of Mineral Resources

A. Nonrenewable Resources – a concentration of naturally occurring material in or on the earth’s crust that can be extracted and processed at an affordable cost. Non-renewable resources are mineral and energy resources such as coal, oil, gold, and copper that take a long period of time to produce.


Nature and formation of mineral resources1

Nature and Formation of Mineral Resources

  • 1. Metallic Mineral Resources – iron, copper, aluminum

  • 2. Nonmetallic Mineral Resources – salt, gypsum, clay, sand, phosphates, water and soil.

  • 3.Energy resource: coal, oil, natural gas and uranium


Nature and formation of mineral resources2

Nature and Formation of Mineral Resources

  • B.Identified Resources – deposits of a nonrenewable mineral resource that have a known location, quantity and quality based on direct geological evidence and measurements

  • C.Undiscovered Resources– potential supplies of nonrenewable mineral resources that are assumed to exist on the basis of geologic knowledge and theory (specific locations, quantity and quality are not known)

  • D.Reserves – identified resources of minerals that can be extracted profitably at current prices.

  • Other Resources – resources that are not classified as reserves.


Ore formation

Ore Formation

1.Magma (molten rock) – magma cools and crystallizes into various layers of mineral containing igneous rock.


Ore formation1

Ore Formation

  • Hydrothermal Processes: most common way of mineral formation

  • A.Gaps in sea floor are formed by retreating tectonic plates

  • B.Water enters gaps and comes in contact with magma

  • C.Superheated water dissolves minerals from rock or magma

  • D.Metal bearing solutions cool to form hydrothermal ore deposits.

    E.Black Smokers – upwelling magma solidifies. Miniature volcanoes shoot hot, black, mineral rich water through vents of solidified magma on the seafloor. Support chemosynthetic organisms.


Ore formation2

Ore Formation

  • Manganese Nodules (pacific ocean)– ore nodules crystallized from hot solutions arising from volcanic activity. Contain manganese, iron copper and nickel.


Ore formation3

Ore Formation

  • 3.Sedimentary Processes – sediments settle and form ore deposits.

  • A.Placer Deposits – site of sediment deposition near bedrock or course gravel in streams

  • B.Precipitation: Water evaporates in the desert to form evaporite mineral deposits. (salt, borax, sodium carbonate)

  • C.Weathering – water dissolves soluble metal ions from soil and rock near earth’s surface. Ions of insoluble compounds are left in the soil to form residual deposits of metal ores such as iron and aluminum (bauxite ore).


Methods for finding mineral deposits

Methods For Finding Mineral Deposits

  • A.Photos and Satellite Images

  • B.Airplanes fly with radiation equipment and magnetometers

  • C.Gravimeter (density)

  • D.Drilling

  • E.Electric Resistance Measurement

  • F.Seismic Surveys

  • G.Chemical analysis of water and plants


Mineral extraction

Mineral Extraction

  • Surface Mining: overburden (soil and rock on top of ore) is removed and becomes spoil.

  • 1.open pit mining – digging holes

  • 2.Dredging – scraping up underwater mineral deposits

  • 3.Area Strip Mining – on a flat area an earthmover strips overburden

  • 4.Contour Strip Mining – scraping ore from hilly areas


Subsurface mining

Subsurface Mining: 

  • 1.dig a deep vertical shaft,  blast underground tunnels to get mineral deposit, remove ore or coal and transport to surface     

  • 2.disturbs less land and produces less waste

  • 3.less resource recovered, more dangerous and expensive

  • 4.Dangers: collapse, explosions (natural gas), and lung disease


Environmental impacts of mineral resources

Environmental Impacts of Mineral Resources

  • A.Scarring and disruption of land,

  • B.Collapse or subsidence

  • C.Wind and water erosion of toxic laced mine waste

  • D.Air pollution – toxic chemicals

  • E.Exposure of animals to toxic waste

  • F.Acid mine drainage: seeping rainwater carries sulfuric acid ( acid comes from bacteria breaking down iron sulfides) from the mine to local waterway

Google earth


Mrs sealy apes

Steps

Environmental Effects

Disturbed land; mining accidents;

health hazards; mine waste dumping;

oil spills and blowouts; noise;

ugliness; heat

Mining

exploration, extraction

Processing

Solid wastes; radioactive material;

air, water, and soil pollution;

noise; safety and health

hazards; ugliness; heat

transportation, purification,

manufacturing

Noise; ugliness

thermal water pollution;

pollution of air, water, and soil;

solid and radioactive wastes;

safety and health hazards; heat

Use

transportation or transmission

to individual user,

eventual use, and discarding

Fig. 14.6, p. 326


Mrs sealy apes

Subsurface

Mine Opening

Surface Mine

Runoff of

sediment

Acid drainage from

reaction of mineral

or ore with water

Spoil banks

Percolation to groundwater

Leaching may carry

acids into soil and

ground

water supplies

Leaching of toxic metals

and other compounds

from mine spoil

Fig. 14.7, p. 326


Mrs sealy apes

Smelting

Separation

of ore from

gangue

Melting

metal

Conversion

to product

Metal ore

Recycling

Discarding

of product

Surface

mining

Fig. 14.8, p. 327

Scattered in environment


A life cycle of metal resources fig 14 8

A.Life Cycle of Metal Resources (fig. 14-8)

  • Mining Ore

  • A.Ore has two components: gangue(waste) and desired metal

  • B.Separation of ore and gangue which leaves tailings

  • C.Smelting (air and water pollution and hazardous waste which contaminates the soil around the smelter for decades)

  • D. Melting Metal

  • E.Conversion to product and discarding product


Economic impact on mineral supplies

Economic Impact on Mineral Supplies

  • A.Mineral prices are low because of subsidies: depletion allowances and deduct cost of finding more

  • B.Mineral scarcity does not raise the market prices

  • C.Mining Low Grade Ore: Some analysts say all we need to do is mine more low grade ores to meet our need

    1.We are able to mine low grade ore due to improved technology

    • 2.The problem is cost of mining and processing, availability of fresh water, environmental impact 


Mrs sealy apes

Mine, use, throw away;

no new discoveries;

rising prices

A

Recycle; increase reserves

by improved mining

technology, higher prices,

and new discoveries

B

Production

Recycle, reuse, reduce

consumption; increase

reserves by improved

mining technology,

higher prices, and

new discoveries

C

Present

Depletion

time A

Depletion

time B

Depletion

time C

Fig. 14.9, p. 329

Time


Mrs sealy apes

Fig. 14.10, p. 329


A mining oceans

A.Mining Oceans

  • 1.Minerals are found in seawater, but occur in too low of a concentration

  • 2.Continental shelf can be mined

  • 3.Deep Ocean are extremely expensive to extract (not currently viable)


A substitutes for metals

A.Substitutes for metals

1. Materials Revolution

  • 2.Ceramics and Plastics

  • 3.Some substitutes are inferior (aluminum for copper in wire)

  • 4.Will be difficult to find substitutes for helium, manganese, phosphorus and copper


Evaluating energy sources

Evaluating Energy Sources

  • What types of energy do we use?

  • 1. 99% of our heat energy comes directly from the sun (renewable fusion of hydrogen atoms)

  • 2. Indirect forms of solar energy (renewable)

    • wind

    • hydro

    • biomass


Mrs sealy apes

Coal seam

Oil and Natural Gas

Coal

Geothermal Energy

Hot water

storage

Contour

strip mining

Floating oil drilling

platform

Oil storage

Geothermal

power plant

Oil drilling

platform

on legs

Area strip

mining

Pipeline

Pipeline

Oil well

Drilling

tower

Mined coal

Gas well

Valves

Water

penetrates

down

through

the

rock

Pump

Underground

coal mine

Water is heated

and brought up

as dry steam or

wet steam

Impervious rock

Natural gas

Oil

Hot rock

Water

Water

Magma

Fig. 14.11, p. 332


Mrs sealy apes

Society

Kilocalories per Person per Day

Modern industrial

(United States)

260,000

Modern industrial

(other developed

nations)

130,000

Early

industrial

60,000

Advanced

agricultural

20,000

Early

agricultural

12,000

Hunter–

gatherer

5,000

Primitive

2,000

Fig. 14.12, p. 333


Mrs sealy apes

Nuclear power

6%

Hydropower, geothermal,

Solar, wind

7%

Natural

Gas

23%

Biomass

12%

Coal

22%

Oil

30%

Fig. 14.13a, p. 333

World


Mrs sealy apes

Nuclear power

7%

Hydropower

geothermal,

solar, wind

5%

Biomass

4%

Natural

Gas

22%

Coal

22%

Oil

40%

Fig. 14.13b, p. 333

United States


20th century trends

20th Century Trends

  • 1. Coal use decreases from 55% to 22%

  • 2. Oil increased from 2% to 30%

  • 3. Natural Gas increased from 0% to 25%

  • 4. Nuclear increased from 0% to 6%


Mrs sealy apes

100

Wood

Coal

80

Natural gas

60

Contribution to total energy

consumption (percent)

Oil

40

Hydrogen

Solar

20

Nuclear

0

1800

1875

1950

2025

2100

Year

Fig. 14.14, p. 334


Evaluating energy sources1

Evaluating Energy Sources

  • Evaluating Energy Resources; Take into consideration the following:

    • Availability

    • net energy yield

    • Cost

    • environmental impact


Mrs sealy apes

Space Heating

Passive solar

5.8

Natural gas

4.9

Oil

4.5

Active solar

1.9

Coal gasification

1.5

Electric resistance heating

(coal-fired plant)

0.4

Electric resistance heating

(natural-gas-fired plant)

0.4

Electric resistance heating

(nuclear plant)

0.3

Fig. 14.15a, p. 335


Mrs sealy apes

High-Temperature Industrial Heat

28.2

Surface-mined coal

Underground-mined coal

25.8

Natural gas

4.9

Oil

4.7

Coal gasification

1.5

0.9

Direct solar (highly

concentrated by mirrors,

heliostats, or other devices)

Fig. 14.15b, p. 335


Mrs sealy apes

Transportation

Natural gas

4.9

Gasoline (refined crude oil)

4.1

Biofuel (ethyl alcohol)

1.9

Coal liquefaction

1.4

Oil shale

1.2

Fig. 14.15c, p. 335


Net energy

Net Energy

  • Net Energy – total amount of energy available from a given source minus the amount of energy used to get the energy to consumers (locate, remove, process and transport)

  • G. Net Energy Ratio - ratio of useful energy produced to the useful energy used to produce it.


Mrs sealy apes

Oil

  • A.Petroleum/Crude Oil – thick liquid consisting of hundreds of combustible hydrocarbons and small concentrations of nitrogen, sulfur, and oxygen impurities.

  • B.Produced by the decomposition of dead plankton that were buried under ancient lakes and oceans. It is found dispersed in rocks.

http://www.schoolscience.co.uk/content/4/chemistry/petroleum/knowl/4/2index.htm?origin.html


Oil life cycle

Oil Life Cycle

  • 1.Primary Oil Recovery

  • a.drill well

  • b.pump out light crude oil

  • 1:14

http://science.howstuffworks.com/oil-drilling3.htm


Secondary oil recovery

Secondary Oil Recovery

  • a.pump water under pressure into a well to force heavy crude oil toward the well

  • b.pump oil and water mixture to the surface

  • c.separate oil and water

  • d.reuse water to get more oil


Tertiary oil recovery

Tertiary Oil Recovery

  • a.inject detergent to dissolve the remaining heavy oil

  • b.pump mixture to the surface

  • c.separate out the oil

  • d.reuse detergent


Mrs sealy apes

  • Transport oil to the refinery (pipeline, truck, boat)


Oil refining

Oil refining

  • – heating and distilling based on boiling points of the various petrochemicals found in the crude oil. (fractional distillation in a cracking tower) 


Mrs sealy apes

Heated

crude oil

Gases

Gasoline

Aviation fuel

Heating oil

Diesel oil

Naphtha

Grease

and wax

Furnace

Fig. 14.16, p. 337

Asphalt


Conversion to product

Conversion to product

  • a.Industrial organic chemicals

  • b.Pesticides

  • c.Plastics

  • d.Synthetic fibers

  • e.Paints

  • f.Medicines

  • g.Fuel


Location of world oil supplies

.     Location of World Oil Supplies

  • 1. 64% Middle East (67% OPEC – 11 countries)

    • a. Saudi Arabia (26%)

    • b. Iraq, Kuwait, Iran, (9-10% each)

  • 2.Latin America (14%) (Venezuela and Mexico)

  • 3.Africa (7%)

  • 4.Former Soviet Union (6%)

  • 5.Asia (4%) (China 3%)

  • 6.United States (2.3%) we import 52% of the oil we use

  • 7.Europe (2%)


Mrs sealy apes

Arctic

Ocean

Arctic National

Wildlife Refuge

Trans Alaska

oil pipeline

Prince William

Sound

Prudhoe Bay

Coal

Beaufort

Sea

ALASKA

Gas

Oil

High potential

areas

Gulf of

Alaska

Valdez

CANADA

Grand

Banks

Pacific

Ocean

UNITED

STATES

Atlantic

Ocean

Fig. 14.17, p. 338

MEXICO


Mrs sealy apes

70

60

50

40

Oil price per barrel ($)

30

20

(1997 dollars)

10

0

1950

1960

1970

1980

1990

2000

2010

Year

Fig. 14.18, p. 339


Mrs sealy apes

40

2,000 x 109

barrels total

30

Annual production

(x 109 barrels per year)

20

10

0

1900

1925

1950

1975

2000

2025

2050

2075

2100

Year

Fig. 14.19a, p. 339

World


Mrs sealy apes

4

200 x 109

barrels total

1975

3

Undiscovered:

32 x 109

barrels

Proven

reserves:

34 x 109

barrels

Annual production

(x 109 barrels per year)

2

1

0

1900

1920

1940

1960

2080

2000

2020

2040

Year

Fig. 14.19b, p. 339

United States


Mrs sealy apes

286%

Coal-fired

electricity

Synthetic oil and

gas produced

from coal

150%

100%

Coal

86%

Oil

58%

Natural gas

17%

Nuclear power

Fig. 14.20, p. 339


Mrs sealy apes

Disadvantages

Advantages

Ample supply for

42–93 years

Need to find

substitute within

50 years

Low cost (with

huge subsidies)

Artificially low

price encourages

waste and

discourages

search for

alternatives

High net

energy yield

Easily transported

within and

between countries

Air pollution

when burned

Low land use

Releases CO2

when burned

Moderate water

pollution

Fig. 14.21, p. 340


How long will the oil last

How long will the oil last

  • 1. Identified Reserve will last 53 years at current usage rates

  • 2.Known and projected supplies are likely to be 80% depleted within 42 to 93 years depending on usage rate

    • US oil supplies are expected to be depleted within 15 to 48 years depending on the annual usage rate


Heavy oils

Heavy Oils

  • Oil Shale – fine grained sedimentary rock containing solid organic combustible material called kerogenShale Oil – kerogen distilled from oil shale.

    a. could meet U.S. crude oil demand for 40 years at current usage rates (Colorado, Utah and Wyoming public lands)

  • Tar Sand – mixture of clay sand and water containing bitumen (high sulfur heavy oil)


Mrs sealy apes

Fig. 14.22, p. 340


Mrs sealy apes

Shale oil pumped to surface

Shale heated to vaporized kerogen, which is condensed to provide shale oil

Mined oil shale

Retort

Conveyor

Spent shale

Above Ground

Conveyor

Pipeline

Impurities

removed

Shale oil

storage

Hydrogen

added

Crude oil

Refinery

Air

compressors

Sulfur and nitrogen

compounds

Air

injection

Shale layer

Underground

Fig. 14.23, p. 341


Mrs sealy apes

Tar sand is mined.

Tar sand is heated

until bitumen floats

to the top.

Bitumen vapor

Is cooled and

condensed.

Pipeline

Impurities

removed

Hydrogen

added

Synthetic

crude oil

Refinery

Fig. 14.24, p. 341


Mrs sealy apes

Advantages

Disadvantages

Moderate existing

supplies

High costs

Low net energy

yield

Large potential

supplies

Large amount of

water needed to

process

Severe land

disruption from

surface mining

Water pollution

from mining

residues

Air pollution

when burned

CO2 emissions

when burned

Fig. 14.25, p. 342


Xi natural gas

XI. Natural Gas

  • Natural Gas is a mixture of 50-90% methane (CH4) by volume; contains smaller amounts of ethane, propane, butane and toxic hydrogen sulfide.

  • B. Conventional natural gas - lies above most reservoirs of crude oil

  • C. Unconventional deposits - include coal beds, shale rock, deep deposits of tight sands and deep zones that contain natural gas dissolved in hot hot water


Mrs sealy apes

Coal seam

Oil and Natural Gas

Coal

Geothermal Energy

Hot water

storage

Contour

strip mining

Floating oil drilling

platform

Oil storage

Geothermal

power plant

Oil drilling

platform

on legs

Area strip

mining

Pipeline

Pipeline

Oil well

Drilling

tower

Mined coal

Gas well

Valves

Water

penetrates

down

through

the

rock

Pump

Underground

coal mine

Water is heated

and brought up

as dry steam or

wet steam

Impervious rock

Natural gas

Oil

Hot rock

Water

Water

Magma

Fig. 14.11, p. 332


Xi natural gas1

XI. Natural Gas

  • Gas Hydrates - an ice-like material that occurs in underground deposits (globally)

  • Liquefied Petroleum Gas (LPG) - propane and butane are liquefied and removed from natural gas fields. Stored in pressurized tanks.

  • Liquefied Natural Gas (LNG) - natural gas is converted at a very low temperature (-184oC)


Where is the world s natural gas

Where is the world’s natural gas?

  • Russia and Kazakhstan - 40%Iran - 15%Qatar - 5%Saudi Arabia - 4%Algeria - 4%United States - 3%Nigeria - 3%Venezuela - 3%


Advantages

Advantages:

1. Cheaper than Oil

2. World reserves - >125 years

3. Easily transported over land (pipeline)

4. High net energy yield

5. Produces less air pollution than other fossil fuels

6. Produces less CO2 than coal or oil

7. Extracting natural gas damages the environment much less that either coal or uranium ore

8. Easier to process than oil

9. Can be used to transport vehicles

10. Can be used in highly efficient fuel cells


Mrs sealy apes

Advantages

Disadvantages

Ample supplies

(125 years)

Releases CO2

when burned

High net energy

yield

Methane

(a greenhouse

gas) can leak

from pipelines

Low cost (with

huge subsidies)

Shipped across

ocean as highly

explosive LNG

Less air pollution

than other

fossil fuels

Sometimes

burned off and

wasted at wells

because of low

price

Lower CO2

emissions than

other fossil fuels

Moderate environ-

mental impact

Easily transported

by pipeline

Low land use

Good fuel for

fuel cells and

gas turbines

Fig. 14.26, p. 342


Disadvantages

Disadvantages:

1. When processed, H2S and SO2 are released into the atmosphere

2. Must be converted to LNG before it can be shipped (expensive and dangerous)

3. Conversion to LNG reduces net energy yield by one-fourth

4. Can leak into the atmosphere; methane is a greenhouse gas that is more potent than CO2.


Xii coal

XII. Coal

  • Coal is a solid, rocklike fossil fuel; formed in several stages as the buried remains of ancient swamp plants that died during the Carboniferous period (ended 286 million years ago); subjected to intense pressure and heat over millions of years.

  • Coal is mostly carbon (40-98%); small amount of water, sulfur and other materials


Three types of coal

Three types of coal

  • lignite (brown coal)

  • bituminous coal (soft coal)

  • anthracite (hard coal)

  • Carbon content increases as coal ages; heat content increases with carbon content


  • Mrs sealy apes

    Increasing heat and carbon content

    Increasing moisture content

    Peat

    (not a coal)

    Lignite

    (brown coal)

    Bituminous Coal

    (soft coal)

    Anthracite

    (hard coal)

    Heat

    Heat

    Heat

    Pressure

    Pressure

    Pressure

    Partially decayed

    plant matter in swamps

    and bogs; low heat

    content

    Low heat content;

    low sulfur content;

    limited supplies in

    most areas

    Extensively used

    as a fuel because

    of its high heat content

    and large supplies;

    normally has a

    high sulfur content

    Highly desirable fuel

    because of its high

    heat content and

    low sulfur content;

    supplies are limited

    in most areas

    Fig. 14.27, p. 344


    Coal extraction

    Coal Extraction

    • Subsurface Mining - labor intensive; world’s most dangerous occupation (accidents and black lung disease Surface Mining - three types

    • 1. Area strip mining2. contour strip mining3. open-pit mining


    Mrs sealy apes

    Coal seam

    Oil and Natural Gas

    Coal

    Geothermal Energy

    Hot water

    storage

    Contour

    strip mining

    Floating oil drilling

    platform

    Oil storage

    Geothermal

    power plant

    Oil drilling

    platform

    on legs

    Area strip

    mining

    Pipeline

    Pipeline

    Oil well

    Drilling

    tower

    Mined coal

    Gas well

    Valves

    Water

    penetrates

    down

    through

    the

    rock

    Pump

    Underground

    coal mine

    Water is heated

    and brought up

    as dry steam or

    wet steam

    Impervious rock

    Natural gas

    Oil

    Hot rock

    Water

    Water

    Magma

    Fig. 14.11, p. 332


    Why we need coal

    Why we need coal

    • Coal provides 25% of world’s commercial energy (22% in US).

    • Used to make 75% of world’s steel

    • Generates 64% of world’s electricity


    Coal fired electric power plant

    Coal-Fired Electric Power Plant

    • Coal is pulverized to a fine dust and burned at a high temperature in a huge boiler. Purified water in the heat exchanger is converted to high-pressure steam that spins the shaft of the turbine. The shaft turns the rotor of the generator (a large electromagnet) to produce electricity.

    http://www.eas.asu.edu/~holbert/eee463/coal.html


    Coal fired electric power plant1

    . Coal-Fired Electric Power Plant

    • Air pollutants are removed using electrostatic precipitators (particulate matter) and scrubbers (gases). Ash is disposed of in landfills. Sulfur dioxide emissions can be reduced by using low-sulfur coal.


    I world s coal supplies

    I. World’s Coal Supplies

    • US - 66% of worlds proven reservesIdentified reserves should last 220 years at current usage rates. Unidentified reserves could last about 900 years


    Pros and cons of solid coal

    . Pros and Cons of Solid Coal

    • Advantages

    • World’s most abundant and dirtiest fossil fuel, High net energy yield


    Mrs sealy apes

    Advantages

    Disadvantages

    Ample supplies

    (225–900 years)

    Very high

    environmental

    impact

    Severe land

    disturbance, air

    pollution, and

    water pollution

    High net energy

    yield

    Low cost (with

    huge subsidies)

    High land use

    (including mining)

    Severe threat to

    human health

    High CO2

    emissions

    when burned

    Releases

    radioactive

    particles and

    mercury into air

    Fig. 14.28, p. 344


    Disadvantages1

    Disadvantages:

    • harmful environmental effects-mining is dangerous (accidents and -black lung disease)-harms the land and causes water pollution-Causes land subsidence-Surface mining causes severe land disturbance and soil erosion-Surface mined land can be restored - involves burying toxic materials, returning land to its original contour, and planting vegetation (Expensive and not often done)-Acids and toxic metals drain from piles of water materials-Coal is expensive to transport-Cannot be used in sold form in cars (must be converted to liquid or gaseous form)-Dirtiest fossil fuel to burn releases CO, CO2, SO2, NO, NO2, particulate matter (flyash), toxic metals and some radioactive elements.-Burning Coal releases thousands of times more radioactive particles into the atmosphere per unit of energy than does a nuclear power plant-Produces more CO2 per unit of energy than other fossil fuels and accelerates global warming.-A severe threat to human health (respiratory disease)


    Clean coal technology

    Clean Coal Technology

    • . Fluidized-bed combustion - developed to burn coal more cleanly and efficiently.

    • Use of low sulfur coal - reduces SO2 emission

    • Coal gasification – uses coal to produce synthetic natural gas (SNG)

    • . Coal liquefaction - produce a liquid fuel - methanol or synthetic gasoline


    Mrs sealy apes

    Flue gases

    Coal

    Limestone

    Steam

    Fluidized bed

    Water

    Air nozzles

    Air

    Calcium sulfate

    and ash

    Fig. 14.29, p. 345


    Mrs sealy apes

    Remove dust,

    tar, water, sulfur

    Raw coal

    Recover

    sulfur

    Air or

    oxygen

    Clean

    Methane gas

    Raw gases

    Steam

    +

    O2

    2CO

    2C

    Coal

    Pulverizer

    Recycle unreacted

    carbon (char)

    CO

    +

    3H2

    CH4

    +

    H2O

    Methane

    (natural gas)

    Slag removal

    Pulverized coal

    Fig. 14.30, p. 345


    Mrs sealy apes

    Advantages

    Disadvantages

    Large potential

    supply

    Low to moderate

    net energy yield

    Higher cost than

    coal

    Vehicle fuel

    High

    environmental

    impact

    Increased surface

    mining of coal

    High water use

    Higher CO2

    emissions than

    coal

    Fig. 14.31, p. 346


    Clean coal technology1

    Clean Coal Technology

    • Synfuels - can be transported by pipeline inexpensively; burned to produce electricity; burned to heat houses and water; used to propel vehicles.


    Xiii nuclear energy

    XIII. Nuclear Energy

    • A. Three reasons why nuclear power plants were developed in the late 1950s:

    • 1. Atomic Energy Commission promised electricity at a much lower cost than coal

    • 2. US Gov’t paid ~1/4 the cost of building the first reactors

    • 3. Price Anderson Act protected nuclear industry from liability in case of accidents


    Mrs sealy apes

    375

    300

    225

    Gigawatts of electricity

    150

    75

    0

    1960

    1970

    1980

    1990

    2000

    2010

    2020

    Year

    Fig. 14.34a, p. 348


    Mrs sealy apes

    35

    30

    25

    20

    Gigawatts of electricity

    15

    10

    5

    0

    1960

    1970

    1980

    1990

    2000

    2010

    Year

    Fig. 14.34b, p. 348


    Why is nuclear power on the decline

    Why is nuclear power on the decline?

    • B. Globally, nuclear energy produces only 17% of world’s electricity (6% of commercial energy)

      -huge construction overruns-high operating costs-frequent malfunctions-false assurances-cover-ups by government and industry-inflated estimates of electricity use-poor management-Chernobyl-Three Mile Island-public concerns about safety, cost and disposal of radioactive wastes


    C how a nuclear reactor works

    C. How a Nuclear Reactor Works

    • Nuclear fission of Uranium-235 and Plutonium-239 releases energy that is converted into high-temperature heat. This rate of conversion is controlled. The heat generated can produce high-pressure steam that spins turbines that generate electricity.


    Mrs sealy apes

    Small amounts of Radioactive gases

    Uranium fuel input

    (reactor core)

    Containment shell

    Emergency core

    Cooling system

    Control

    rods

    Heat

    exchanger

    Hot coolant

    Hot coolant

    Coolant

    Coolant

    Moderator

    Coolant

    passage

    Pressure

    vessel

    Shielding

    Waste heat

    Electrical power

    Steam

    Useful energy

    25 to 30%

    Generator

    Turbine

    Hot water output

    Condenser

    Pump

    Pump

    Cool water input

    Black

    Pump

    Waste

    heat

    Water

    Waste

    heat

    Water source

    (river, lake, ocean)

    Periodic removal

    and storage of

    radioactive wastes

    and spent fuel assemblies

    Periodic removal

    and storage of

    radioactive liquid wastes

    Fig. 14.32, p. 346


    Mrs sealy apes

    Spent fuel

    assemblies

    Spent fuel

    assemblies

    Decommissioning

    of reactor

    Decommissioning

    of reactor

    Spent fuel assemblies

    Fuel assemblies

    Reactor

    (conversion of enriched UF6 to UO2

    and fabrication of fuel assemblies)

    Open fuel cycle today

    Prospective “closed” end fuel cycle

    Fuel fabrication

    Interim storage

    Under water

    Enriched

    UF6

    Plutonium-239

    as PuO2

    Enrichment

    UF6

    Spent fuel

    reprocessing

    Uranium-235 as UF6

    High-level

    radioactive

    waste or

    spent fuel

    assemblies

    Conversion of U3O8

    to UF6

    Uranium tailings

    (low level but

    long half-life)

    Processed

    uranium ore

    Geologic disposal

    of moderate-

    and high-level

    radioactive wastes

    Uranium mines and mills

    Ore and ore concentrate (U3O8)

    Fig. 14.33, p. 347

    Front end

    Back end


    D light water reactors lwr

    D. Light-water reactors (LWR)

    • 1. Core containing 35,000-40,000 fuel rods containing pellets of uranium oxide fuel. Pellet is 97% uranium-238 (nonfissionable isotope) and 3% uranium-235 (fissionable).

    • 2. Control rods - move in and out of the reactor to regulate the rate of fission

    • 3. Moderator - slows down the neutrons so the chain reaction can be kept going [ liquid water in pressurized water reactors; solid graphite or heavy water (D2O) ].

    • 4. Coolant - water to remove heat from the reactor core and produce steam


    Decommissioning power plants

    Decommissioning Power Plants

    • 1/3 of fuel rod assemblies must be replaced every 3-4 years. They are placed in concrete lined pools of water (radiation shield and coolant).

    • A. Nuclear wastes must be stored for 10,000 years

    • B. After 15-40 years of operation, the plant must be decommissioned by

    • 1. dismantling it

    • 2. putting up a physical barrier, or

    • 3. enclosing the entire plant in a tomb (to last several thousand years)


    Mrs sealy apes

    Advantages

    Disadvantages

    Large fuel

    supply

    High cost (even

    with large

    subsidies)

    Low

    environmental

    impact (without

    accidents)

    Low net

    energy yield

    High

    environmental

    impact (with major

    accidents)

    Emits 1/6 as

    much CO2 as coal

    Moderate land

    disruption and

    water pollution

    (without

    accidents)

    Catastrophic

    accidents can

    happen

    (Chernobyl)

    No acceptable

    solution for

    long-term storage

    of radioactive

    wastes and

    decommissioning

    worn-out plants

    Moderate land use

    Low risk of

    accidents

    because of

    multiple

    safety systems

    (except in 35

    poorly designed

    and run reactors

    in former Soviet

    Union and

    Eastern Europe)

    Spreads

    knowledge and

    technology for

    building nuclear

    weapons

    Fig. 14.35, p. 349


    Mrs sealy apes

    Coal

    Nuclear

    Ample supply

    Ample supply

    of uranium

    High net energy

    yield

    Low net energy

    yield

    Low air pollution

    (mostly from fuel

    reprocessing)

    Very high air

    pollution

    High CO2

    emissions

    Low CO2

    emissions

    (mostly from fuel

    reprocessing)

    65,000 to 200,000

    deaths per year

    in U.S.

    About 6,000

    deaths per

    year in U.S.

    High land

    disruption from

    surface mining

    Much lower land

    disruption from

    surface mining

    High land use

    Moderate land

    use

    Low cost (with

    huge subsidies)

    High cost (with

    huge subsidies)

    Fig. 14.36, p. 349


    F advantages of nuclear power

    F. Advantages of Nuclear Power:

    • 1. Don’t emit air pollutants

    • 2. Water pollution and land disruption are low


    G nuclear power plant safety

    G. Nuclear Power Plant Safety

    • 1. Very low risk of exposure to radioactivity

    • 2. Three Mile Island - March 29, 1979; No. 2 reactor lost coolant water due to a series of mechanical failures and human error. Core was partially uncovered

    • 3. Nuclear Regulatory Commission estimates there is a 15-45% chance of a complete core meltdown at a US reactor during the next 20 years.

    • 4. US National Academy of Sciences estimates that US nuclear power plants cause 6000 premature deaths and 3700 serious genetic defects each year.

    http://www.angelfire.com/extreme4/kiddofspeed/chapter1.html


    Mrs sealy apes

    Automatic safety devices

    that shut down the reactor

    when water and steam levels

    fall below normal and turbine

    stops were shut off because

    engineers didn’t want systems

    to “spoil” experiment.

    Almost all control rods

    were removed from the

    core during experiment.

    Emergency cooling

    system was turned

    off to conduct an

    experiment.

    Cooling

    pond

    Cooling

    pond

    Turbines

    Turbines

    Radiation shields

    Radiation shields

    Reactor

    Reactor

    Additional water pump to cool reactor

    was turned on. But with low power output

    and extra drain on system, water didn’t

    actually reach reactor.

    Reactor power output was lowered too

    much, making it too difficult to control.

    Crane for

    moving fuel rods

    Steam

    generator

    Water

    pumps

    Chernobyl

    Fig. 14.37, p. 350


    H low level radioactive waste

    H. Low-Level Radioactive Waste

    • 1. Low-level waste gives off small amounts of ionizing radiation; must be stored for 100-500 years before decaying to levels that don’t pose an unacceptable risk to public health and safety

    • 2. 1940-1970: low-level waste was put into drums and dumped into the oceans. This is still done by UK and Pakistan

    • 3. Since 1970, waste is buried in commercial, government-run landfills.

    • 4. Above-ground storage is proposed by a number of environmentalists.

    • 5. 1990: the NRC proposed redefining low-level radioactive waste as essentially nonradioactive. That policy was never implemented (as of early 1999).


    I high level radioactive waste

    I. High-Level Radioactive Waste

    • 1. Emit large amounts of ionizing radiation for a short time and small amounts for a long time. Must be stored for about 240,000

    • 2. Spent fuel rods; wastes from plants that produce plutonium and tritium for nuclear weapons.


    J possible methods of disposal and their drawbacks

    J. Possible Methods of Disposal and their Drawbacks

    • 1. Bury it deep in the ground

    • 2. Shoot it into space or into the sun

    • 3. Bury it under the Antarctic ice sheet or the Greenland ice cap

    • 4. Dump it into descending subduction zones in the deep ocean

    • 5. Bury it in thick deposits of muck on the deep ocean floor

    • 6. Change it into harmless (or less harmful) isotopes

    • 7. Currently high-level waste is stored in the DOE $2 billion Waste Isolation Pilot Plant (WIPP) near Carlsbad, NM. (supposed to be put into operation in 1999)


    Mrs sealy apes

    Up to 60

    deep trenches

    dug into clay.

    As many as 20

    flatbed trucks

    deliver waste

    containers daily.

    Barrels are stacked

    and surrounded

    with sand. Covering

    is mounded to aid

    rain runoff.

    Clay bottom

    Fig. 14.38b, p. 351


    Mrs sealy apes

    Grass

    Topsoil

    Gravel

    Soil

    Compacted clay

    Sand

    Gravel

    Clay

    What covers waste

    Fig. 14.38c, p. 351


    Mrs sealy apes

    Waste container

    2 meters wide

    2–5 meters high

    Several

    steel drums

    holding waste

    Steel wall

    Steel wall

    Lead shielding

    Fig. 14.38a, p. 351


    Mrs sealy apes

    Storage Containers

    Fuel rod

    Primary canister

    Overpack container

    sealed

    Fig. 14.39c, p. 352


    Mrs sealy apes

    Underground

    Buried and capped

    Fig. 14.39d, p. 352


    Mrs sealy apes

    Ground Level

    Unloaded from train

    Lowered down shaft

    Fig. 14.39a, p. 352


    Mrs sealy apes

    2,500 ft.

    (760 m)

    deep

    Personnel elevator

    Air shaft

    Nuclear waste shaft

    Fig. 14.39b, p. 352


    K worn out nuclear plants

    K. Worn-Out Nuclear Plants

    • 1. Walls of the reactor’s pressure vessel become brittle and thus are more likely to crack.

    • 2. Corrosion of pipes and valves


    3 decommissioning a power plant 3 methods have been proposed

    3. Decommissioning a power plant (3 methods have been proposed)

    • A. immediate dismantling

    • B. mothballing for 30-100 years

    • C. entombment (several thousand years)

    • 4. Each method involves shutting down the plant, removing the spent fuel, draining all liquids, flushing all pipes, sending all radioactive materials to an approved waste storage site yet to be built.


    Connection between nuclear reactors and the spread of nuclear weapons

    Connection between Nuclear Reactors and the Spread of Nuclear Weapons

    • 1. Components, materials and information to build and operate reactors can be used to produce fissionable isotopes for use in nuclear weapons.

    Los Alamos Muon Detector Could

    Thwart Nuclear Smugglers


    M can we afford nuclear power

    M. Can We Afford Nuclear Power?

    • 1. Main reason utilities, the government and investors are shying away from nuclear power is the extremely high cost of making it a safe technology.

    • 2. All methods of producing electricity have average costs well below the costs of nuclear power plants.


    N breeder reactors

    N. Breeder Reactors

    • 1. Convert nonfissionable uranium-238 into fissionable plutonium-239

    • 2. Safety: liquid sodium coolant could cause a runaway fission chain reaction and a nuclear explosion powerful enough to blast open the containment building.

    • 3. Breeders produce plutonium fuel too slowly; it would take 1-200 years to produce enough plutonium to fuel a significant number of other breeder reactors.


    O nuclear fusion

    O. Nuclear Fusion

    • 1. D-T nuclear fusion reaction; Deuterium and Tritium fuse at about 100 million degrees

    • 2. Uses more energy than it produces


  • Login